AGE

Acmma lestudinalis Müller, ~ :

tomy of. I 191

Adaptive En ifoations ae oc-

cipital condyles in a

en notes on Baham

nakes

Additional record for en Eng-

rustac

Affinities of Bad Crobascous

plant remains commonly re-

ferred to the genera Dammara

and Brachyphyllum «1

jc G. M. Sowerby's hee.

n the American coast . 357

An Flora of Colorado . . 861

Anatomy of Acmea adinak

Müller. Part I 71

m of Cryploranchus ille

ghenien

Andrews, E k Tirar of

crayfish

Application af de Vries’ s miata

tion theory to the Mollusca 327

Arcella, apices study of

finer structure

Autodax bue. Pastore of at

Los Angeles, Cal. ot

Ayers, H. Unity of the gnatho-

stome type ,

. 943

[um

Bacon, R., et al. a of

tancum bbers

Baker, F. C Appliontion of de

Vries’s mutation theory to the

Mollusca 827

iy "Additional - sob

n Bahama snakes . 220

Batrachians of Pennsylvania,

New Jersey, and

Delaware

Notes on reptiles and 159

Berry, E. W. Living and fossil

species of Comptonia

p relations of doriai

dul ‘ills d finum pidin 875

Brachiopoda, Old age in . 95

Bryant, O. Recent extension of

the range of the green crab 382

Burgess, W. S. See Weysse, A.

W., and ——.

Cacti, Biological relations of

re M

Cannon, W. A. Biological rela-

tions of certain cacti 27

pde of big salamander,

utodax at Los

ee er . 741

Causes of extinetion of Maias

, 829

Cedar Point, Ohio, Naididie of 683

Cockerell, T. D. A. Alpine flora

of Colorado .

Cole, L. J. A new yenogonid

from the as ;

Colorado, Alpine flora vis

Comptonia, Living and

species of

Condyles,

modific

. MT

. 861

fossil

. . ABD

dodi pitul, Adaptive

ations of in en 475

f n E

Contributions to the visi n

and biology of the dugong .

Jand — -.

Copepoda of Massachusetts,

Congress of

Porsild, M. P. The Danih

arctic station .

Crayfish, Egg-laying of

Cretaceous plant remains, Affini-

ties of certain

diaries

Anato

alleghenienss,

INDEX

PAGE

Copepoda, Marine, of Rhode Is-

: . 343

. 189

Ber

eg 4. r Additional rec-

dene for New England Crus-

tac

Vedi Aaii of

Nantucket

Cushman, J. i pe Henderson,

wW. P P.

ry study

the finer structure of paa

DAmmMARA and Brachyphyllum,

Affinities of certain Cretaceous

plant remains commonly re-

ferred to the genera ;

Danish arctic station . .

Dexler, H., and Freund, L. Con:

tributions to the physiology

and biology of the dugong

ge: gas of the

Double Thang indio : i

Dragonflies in brackish Vier.

|. and experiments

-3

Dugong, El morphology

. 141

797

. 53

. 567

Duong Physiology and biology

Deut D.

AUS and an unfixed law of

Nat

Ecc-rLav1NG of crayfish

External pene d of the du-

gong .

Flying-fish

. 343

Extinction of Mammalia, pes

, 82

Erkennen: A C. The Tied

of Necturus maculosus

FiNER structure of Arcella, Pre-

liminary study of

Fishes, Notes on Penneyivanis

Flora of Colorado, a

Flow of sap in ma

Flying-fish flight. and an infixed

aw of Nature í

Fowler, H.W. Noteon EM uen

bepet v v.

——- Notes on igno his

fishes,

—— PR elatis in te

Lower Susque

Fragmental edit: | Eeiodub-

tion by, in Metridium i

Fresh-water Copepoda of Mass:

achusetts

Fresh-water ET ol Nan-

tucket

aa.

Freund, L. oe Derler, H.. lod

Girts, Blood, of Simulium pic-

HM S |. o» o3

| Gnathostome type, Unity of

HaBrrs of Necturus maculosus

Simulium pictipes

Henderson,

Histogenesis of the retina . .

Hollick, A., and Jeffrey, E. C.

Affinities of certain Cretaceous

plant remains commonly re-

ferred to the genera Dammara

and Brachyphyllum

P. See Sr

PAGE

. 189

sad o

RETTET

WEM 5 a EDEL NE P T aay ee nee 43 1s

oS N NEE hls TER TE e gu. o 0t ee

JEFFREY, E. C. See Hollick,

A., and ——

Kerner, W. A. Notes on the

genus Leptophrys

LEPTOPHRYSs, Notes on the genus

Lichens of ne Monadnock,

pshire .

Fa)

— ne are ies of Comp

toni

eiie Variation in her of

INDEX

. 335

335

661

. 485

787

Lull, R. " Volant adaptation

: . 537

in vertebrates

MAMMALIA, Causes of extinction

[o . 769,

~ us und flow " sap

M Copepsdh a Rhode P

land, Noteson .

Mead, C. S. Adaptive modë-

cations of occipital condyles in

ammala . 22 € 235

Mechanism of the odontophoral

apparatus in Sycotypus can-

aliculatus

Metridium margi uv. Repn

duetion of by fragmental ds.

NOD . . 20 25. ut

Miller, L. H. Capture of the

salamander, Autodax —

at Los Angeles, Cal.

Mollusea, Application of p

Vries's mutation theory to the

ren External, of the

dugon.:

Mount RR Lidess e i

Muhlenberg’s turtle, Note on

. Mutation Dm jen of,

to the Mollus

Naipipa of Cedar Point, Ohio

Nantucket, Fresh-water rhizo-

Necturus ae SUS, : Habits of

New England Crustacea, Addi-

tional records for

829

. 639

475

. 371

123

; 141

New Hampshire, Lichens of

Mount Monadnock . . . 661

New gg from the Ba-

ham . 217

Notes er Litst:

Anthropology sea ff

Anthropology, Notes <o M

Astronomy and M ss » o. 803

Biol 804

gy . 739,

Botany 143, 461, 600, 814

Botany, Pe

148, 464, d 744, 815

Botany, The Journa

153, 471, "673, 751, en

456

Evolution . . .

PROGR . . 2 3. . . 458

Geology soe . 52

Geology, Notes 155, 529

Paleontolo, vos a

duca Notes FI. ve

Ze 137, 375, 593, 741, iis

Zoólogy, Ichthyological Notes,

5, 808

Zoölogy, Notes 141, 382, 743

Note on Muhlenberg’s turtle . 596

Notes on the genus Leptophrys 335

Notes on marine Copepoda of

Rhode Islan . 639

Notes on Praneyivanii Dha . 595

Notes on reptiles and batrachians

of oe New Jersey,

Number of atk of lotos, aas

Höhn: . 27 7. o0 2 I

OBSERVATIONS and experiments

on dragonflies in brackish

water . 395

Occipital condyles i in | Mammalia,

Adaptive modifications of . 475

Odontophoral apparatus in Sy-

cotypus canaliculatus, Mechan-

ism of 7

Ohio, Kaidi of Cedar Poink 683

Old age in Brachiopoda — a pre:

liminary study 95

Osborn, H. F. Causes of ariin

tion of Mammalia 769, 829

vi | INDEX

PAGE

Osburn, R. C. Observations

and experiments on dragon-

flies in brackish water .

Parker, G. H. Double hens’

ERBE o a er

Pearl, R. Variation in number

of seeds of lotus . . 757

Pearse, A.S. Vred-wator Cope:

poda of Massachusetts Be

Reactions of Tubularia

crocea (Ag.)

Pennsylvania fishes, Notes omn . 595

Physiology and biology of the

MO ce 5. 25

Picea excelsa, Variations in the

poll Be... ee

Pimephales notatus in the Lower

Busquehänna . . . 4 . -TAS

Pollen ie Ad Picea excelsa,

Variations . 253

Pollock, J. B. Variations in ds

pollen grain of Picea excelsa 253

Preliminary study of fnac. Mus.

ture of Arcella . . 197

m and flow of | in the

aple . 409

Kika reod vod 233, 677, 887

MIN from the Bahamas,

RANGE of the green crab, Recent

extension of . : 382

Reactions of Tubularia crocea

Recent SEP of the range of

the gree

Reese, ki M Anatomy of of Cru»

tobranchus alleghenien . 287

Reproduction of M. wore mar-

ginatum by fragmenta! fission 583

Retina, Histogenesis of "c | 611

Reviews:

Alder and Hancock's British

Tunicates .

pug s Dositatio de Bo-

ay MB

Brooks's s The Oyster . (0.7. 8H

PAGE

Campbell's Structure and De-

nn of Mosses and

ern . 603

edes on dedit Biruction . 814

Clements’s Research Methods

in Ecology . . 804

nn. obest ut

Plant . 605

Farlow's 8 Bibliographical ie

dex of North American

ungi

Freeman's ee "Plant

Diseases

D v4 s .4

Hantzsch’s Birds of Iceland . 139

arris on Anther Dehiscence 461

Holder’s Half Hours with the

Lower Animals . . 140

R. H. and M. A. Howe's Can:

mon and Conspicuous Li-

chens of New England . . 605

Jenks's The Bontoc Igorot . 597

Jordan's Guide to the Study

of Fishes . 52

Kellogg's American Inmssete . 137

Kingsley’s Elements of Com-

parative Zoölogy . Do. 1108

Lacouture's Liverw ads of

France . . 608

Lankester’s Extinet Animali . 526

Loeb's I of Living

Matte . 739

Lotsy's Thess of Dini . 456

TO s Special Method in

Elementary Science . . . 455

Mayer’s vno Life . 378

Moore's Universal Kinship. . 805

EE s Experiments with

Plan

ee of ‘Northern Sees: i . 593

Pratt’s Vertebrate Zoólogy . 806

Punnett's Mendelism . . . 139 -

Ries’s Economie Geology of

the United States . . . 528

Sabine's Manual of a tabiii

C in Physical

Measurements .

Sargent’s ap = the Trees

of North Am

Schillings’s With “Psi

and Rifle

Er A IT

Scott’s

covery

Smith’s Basis in Relation

to Plant Diseases

Stephens’s California Win-

mals

Ward’s

Trees and Shrubs

Weismann’s The Micaisition

ee ae

Wiesner on Light Intensity

Wiesner on Plants and Light 6

Willson’s Laboratory Astron-

DEAE VS SO a ae

Rhizopods, Fresh-water, of Nan-

NEN |. — . — 3

SALAMANDER, Autodax lugubris,

Capture of at Los Angeles,

CH. iar 3 5s ded

Sap in maple, Pressure and flow

o ox ud y Vx d

Seeds of lotus, Variation in num-

ror 2... IAN sus

Shimer, H. W. Old age in

Brachiopoda — a preliminary

a i 5 74 4 4a

Simulium pictipes, Blood gills of 875

Snakes, Additional notes

Banara 512. S V

Sowerby's whale on the Ameri-

Stone, W. Notes on reptiles

and batrachians of Pennsyl-

Voyage of the Dis-

F lowes "m English

INDEX

AGE

375

815

229

vania, New Jersey, and Dela-

WEM. al i;

Structure of Arcella, Preliminary

study of WO PRACT

Study, Preliminary, of finer

structure of Arcella

Sycotypus canaliculatus, Wakin-

ism of —— —

ipn crocea (Ag.), Reac-

Turtle, Mublenberg’ 8, ‘Note. on

Unity of the gnathostome type

VARIATION in number of seeds of

lotus

_ Variations in the pollen grain of

| wea eXceisa á €^. ^. ye

| Vertebrates, Volant adaptation

in KW A El Oi E. T

Volant adaptation in vertebrates

Watton, L. B. Naidide of

Cedar Point, Ohio .

Weysse, A. W., and Bur atiu, w.

S. Pistigenesia of the retina

Whale, Sowerby’s, on the Ameri

can coast

Wiegand, K. "i Pressure ad

; . 409

Williams, `

marine €— of Rhode

Island :

vil

AGE

. 197

. 707

. 4

596

537

611

. 357

. 639

THE

AMERICAN NATURALIST

Vor. XL January, 1906 No. 469

FLYING-FISH FLIGHT, AND AN UNFIXED LAW OF

NATURE

C. D. DURNFORD

THE controversy amongst naturalists as to whether flying-fish

do or do not flap their wings in flight has become so one-sided as

almost to represent extinction — as a controversy.

It is desirable, if possible, to revive it a little, by carrying the

argument into new ground: first, because the one side which is

at present believed in would appear to be the wrong one; and,

secondly, because it seems to have escaped the notice of the other

that this is capable of proof.

The arguments, if they may be so called, hitherto in use are

simple assertion and denial, and may be summed up into:—

“Flying-fish do fly, moving their wings with extreme rapidity.

I have carefully and frequently watched them and there can be

no doubt whatever about it.”

And the converse:—

“Flying-fish do not flap their wings, but use them as aéroplanes,

like swallows when in skimming or sailing flight. I have carefully

and frequently watched them, and there can be no doubt whatever

about it.”

Somewhat similar remarks will be heard in any ordinary group

of ship’s passengers watching the fish. Some will insist that they

see the wings flapping, and some will aver that they are quite still.

2 THE AMERICAN NATURALIST [Vor. XL

But among scientists wing-flapping is undoubtedly very much

the under dog and the carefully written paper by Captain Barrett-

Hamilton (Ann. Mag. Nat. Hist., ser. 7, vol. 11, p. 389, 1903), also

a convinced aéroplanist, perhaps expresses current opinion as well

as may be; and even Professor Whitman (Amer. Naturalist, vol.

14, p. 641, 1880), who insists that he has seen “distinctly the indi-

vidual flaps of the large pectorals," adds that this flapping “may

be continued for the whole or part of the flight, but it is generally

discontinued after the first few rods, and the course continued by

a pure skimming or sailing movement"— thus showing that he,

too, believes in the possibility of the aéroplane flight. =~

Proof that such flight by any known species of flying-fish is a

mechanical impossibility is the new ground which I propose to take

up.

In order to make clear what the aéroplane theory is, I quote

from the Encyclopedia Britannica (art. * Flying-fish") the “chief

results of the inquiries” (Die Bewegungen der Fliegenden Fische

durch die Luft, Leipzig, 1878) of one of its chief exponents, Pro-

fessor K. Mébius. ‘These results, which seem also to have formed

the groundwork of many subsequent articles, are — with certain

omissions on my part for brevity’s sake — summed up as follows:—

“ They are more frequently observed in rough weather, and in

a disturbed sea then during calms; they dart out of the water... .

and they rise without regard to the direction of the wind or waves.

The fins are kept quietly distended without any motion, except

an occasional vibration caused by the air, whenever the surface

of the wing is parallel with the current of the wind. Their flight

is rapid, but gradually decreasing in velocity, greatly exceeding

that of a ship going ten miles an hour, and a distance of 500 feet.

Generally it is longer when the fishes fly against, than with, or at

an angle to, the wind. Any vertical or horizontal deviation from

the straight course, when flying with or against the wind, is not

caused at the will of the fish, but by currents of air... .in a rough

sea, when flying against the course of the waves; they then fre-

quently overtop each wave, being carried over it by the pressure -

of the disturbed air. They...:fall on board vessels. This never

happens from the lee side, but during a breeze only, and from the

weather side. During the night they frequently fly against the

No. 469] FLYING-FISH FLIGHT 3

weatherboard, where they are caught by the current of air and

carried upwards to the height of 20 feet above the surface of the

water, whilst under ordinary circumstances they keep close to it.”

The above is fairly representative of the aéroplane theory.

There are, however, several variants to it, the most notable being

the addition by later writers of the use of the tail, both as a propeller

in air, and also as an explanation of the loud buzzing sound always

heard when the fish fly near or over a boat, and which is really

made — it seems odd to have to write it — by the rapid whirring

of the wings.

Of this whirring or flapping motion Professor Whitman writes:

“Tt is so rapid that it is not easily recognized at any great distance

until experience has sharpened the eye.” Therein lies, I think,

the cause of the birth of the aéroplane theory, though I must add

that experience need not necessarily sharpen even good natural

sight into. being able to see the wing-movement. Knack or chance

may come in in such matters. Some time ago, for instance, I

was astonished, whilst testing the shooting of a shot-and-ball gun

at the butts, to find that in certain lights I could plainly see the

ball during its whole flight, whilst the attendant, whose daily busi-

ness it was to test rifles and guns, and whose sight was far supe-

rior to mine, tried over and over again but could not pick it up.

So have I seen many watch the whirring wings and declare them

to be still.

It is commonly accepted that in matters of observation an affirm-

ative evidence is superior to a negative one. In the special case

under consideration, the value of the affirmative true flight evi-

dence is very greatly increased by the fact that the aéroplane

contradiction thereof must be in proof of a unique act in nature

without a known parallel. Flying lizards and flying squirrels

are perhaps the nearest, but in both cases the aéroplane is, I believe,

greater by far compared with the weight borne, and — of more

importance — the course is certainly far less and falling, not hori-

zontal, or rising, as is that of the flying-fish.

Surely, therefore, it is not too much to ask from the aéroplanists

either a reference to some mechanical parallel, or else absolutely

overwhelming evidence in favor of the marvellous —a fair

expression if no parallel be produced. We do not receive the

4 THE AMERICAN NATURALIST [Vor. XL

evidence, for, as before noted, it consists of a series of witnesses

very fairly divided as to whether they can or cannot see the wing-

movement, although scientific writers on the subject nearly all

follow the latter. We do receive reference to certain parallels,

and I shall endeavour to examine these with such lights as I can

find. The parallels are, first, the “sailing” or skimming flight

of birds (swallows being usually mentioned), and, secondly,

parachutes.

For purposes of comparison in this examination, we will take a

typical flying-fish. I have the wings of one, which flew on board

a steamer on which I was traveling, before me as I write. Its

weight was just over a pound, and it had a wing-area of 62 square

inches, very liberally computed.

Let us consider the bird-flight first. Concerning this we have

certain recognized facts to guide us, for which I refer readers to

Professor E. J. Marey’s work on Animal Mechanism (vol. 2, pp.

221-225, 1874).

We are specially concerned in his acceptance therein of the

division of birds into two main classes, viz., those largely given

to "sailing" or still-wing flight (which class is found to be endowed

with a large wing-surface), and those which confine themselves

more to the “rowing” or wing-flapping flight (which, as a class,

have short and narrow wings).

“Tf,” says Professor Marey (loc. cit., p. 221), “we compare

together two rowing, or two sailing. ..,” arranging as far as possi-

ble “to have no difference between them except that of size, we

shall find a tolerably constant ratio between the weights of these

birds and the surface of their wings." Tables are added of this

ratio in various birds, as found by dividing the square root of their

wing-surface in square centimeters by the cube root of their weight

in grammes.

I will from these tables give this ratio for three of the sailing

birds and for three of the rowing birds, including the two lowest

ratios of the latter. I will add on my own account the ratio for

the flying-fish, which is quite properly comparable with birds in

this respect.

No. 469] FLYING-FISH FLIGHT 5

| : ;

| eight= rf f wings

Name ee | | ion —

| in grams | —2a in sq. em. n

Falco palustris...... l 208.76 | 1188 | 5.810

Falco subbuteo(?)..... | 509.62 | 1684 | 5.138

iru urbica | |

(House martin) .... 18.00 | 120 | 4.180

Columba vinacea......| 112.00 | 292 3.545

cola Ihe... | 56.05 | 125 2.922

Perdix cinerea... ..... .| 280.00 | 320 2,734

Exocetus (Flying-fish) 453.59 400 2.603

Note the place of the flying-fish. It is quite in its proper posi-

tion as a very low order of wing-flapper, requiring great wing-

speed to sustain it in air. Note also the representative of the

swallow tribe, weighing considerably under an ounce, in its proper

place in the sailing class. ‘The Hirundo rustica, or swallow proper,

would doubtless hold a higher place still — our principal parallel,

whose featherweight ought to have protected us from the com-

parison.

The figures should be convincing; I will not, therefore, com-

ment more upon this, but proceed to another test, viz., to find what

size of wing a one-pound (453 grams) fish would require to raise

it into the sailing class. No birds are dealt with by Marey of

exactly one pound weight; I will therefore take the next above

and the next below that weight.

The Falco subbuteo above shown has a weight of 509 grams

and a wing-area of 1684 sq. cm., with ratio of 5.138, and the Corvus

cornix has a weight of 374 grams and a wing-area of 1156 sq.

cm., giving a ratio of 4.717.

Our one-pound flying-fish, to enable it to sail, would thus require

a wing-area between three and four times greater than the 400

sq. cm., which it possesses. And, mark this, even then it would

only sail as birds sail, in favorable winds and circumstances,

falling and rising and using the “rowing” flight frequently, as

may be necessary, not as our fishes go, "without regard to the

direction of the wind," horizontally, and close to tbe water, and,

according to aéroplanists, with ever still wings! Further, “concave

bird-like surfaces afford from 3 to 7 times as much support as

6 THE AMERICAN NATURALIST [Vor. XL

planes.” (Encycl. Brit., art. “ Aöronautes,—re flight.’”’) It has

been pointed out to me that it is extremely improbable that a

flying fish’s wings can assume this concave shape. If this be so,

“from 9 to 28" may be substituted for “‘between three and four"

times, above.

Need I go on? I am afraid so —superstitions, especially

learned ones, die hard. So to the second parallel offered us, the

parachute. The term implies the act of falling through the air,

and not the horizontal or the rising motion with which we are

dealing. Still, the word has been used in explanation of the fish’s

supposed deeds, and I will try to deal with it and at the same time

keep clear of the pitfalls which will surround the effort.

Professor Móbius puts the speed of the flying-fish as “greatly

exceeding that of a ship going 10 miles an hour." George Bennett

(Wanderings in New South Wales, vol. 1, p. 31, 1834), much

quoted, puts its extreme time in air at 30 seconds “by the watch,”

and its distance at 200 yards; this works out at rather over 133

miles an hour, extreme rate. It will, perhaps, give a sufficiently

large margin to call the fish’s average speed 15 miles an hour.

Now if wind and a body, either or both in motion, meet at a

rate of 15 miles an hour directly against each other, the body hav-

ing 1 square foot of surface, the pressure exerted thereon will be

1.107 Ibs. That, I think, implies that if a flying-fish weighing a

little over a pound and having a wing-surface of 144 square inches

(an impossibly large one, of course, for such a fish) were falling

through still air, it would descend at the rate of about 15 miles an

hour; or, on the other hand, if it were in a wind blowing 15 miles

an hour straight upward from the sea (an impossibly favoring

wind, of course) it would just be supported. I will leave it entirely

to my readers to imagine the effect in the second case upon our

fish of reducing its wing-area from the suppositious 144 sq. inches

to its actual 62 sq. inches.

If the reader’s imagination is not sufficient to drop the fish into

the sea at once by the reduction, then let him add the effect of

removing as much support as would be taken away by changing

the impossible upward-blowing wind into the ordinary horizontal

one at the same 15 miles an hour speed, meeting the wings at an

acute angle. There are pitfalls here, so I will avoid angles and

No. 469] FLYING-FISH FLIGHT 7

calculations, and merely point out that, however much scientists

may differ as to the amount of the loss of the supporting power

involved, none will dispute that there will be a very great loss.

Yet again, if these descents from favoring suppositions to

sober facts will not convince, I must advance one more argument.

It is, I believe, like the others, new ground, and I will give it a

fresh paragraph.

Flying-fish, at the end of their first flight of usually about 10 to

50 yards, have a habit, especially when approaching the crest of a

wave, of momentarily checking their wing-movement and slowing

down from the blur of great rapidity into a pace in which the

flapping of the wing becomes easily visible. This period of visi-

bility is supposed by aéroplanists to be the only portion of the

flight during which the wings move, and they even deny them at

this time any supporting power whatever. It is their “period of

occasional vibration” or “fluttering,” and their explanation thereof

will make a mechanician smile or feel sad, according to his tem-

perament. I have already quoted it from Mébius, and it amounts

to the wings trailing in the wind like a loosely flapping flag, thus

not only depriving the heavy fish of the so called support of its

miniature aéroplanes, but actually converting them into an active

drag.

And yet, according to the theorists, at an extreme suggested

speed of 133 miles an hour, the fish still sails!

Such an upsetting of one of the best known of nature’s laws as

all the foregoing implies would be impossible of final acceptance,

even if we could not, as many of us can, see the flying-fish flying.

I studied the “vibration” or flutter periods very carefully this

spring when returning from the Gulf of Mexico. Their object

and method seemed simple and clear, and to be as follows: the

slowing down from extreme wing-speed into visibility heralds an

immediate increased effort of flight, often, if not usually, to enable

the fish to surmount a wave. The fish is, in fact, pulling itself

together for a spurt. The flutter, as was to be expected, is accom-

panied by a slight fall of the fish of perhaps 2 or 3 inches; but the

spurt, at once put on, regains the lost elevation and lifts the fish

well over the obstacle. This sudden rise of the fish (the “fre-

quently overtop each wave” of Möbius) is constantly to be seen,

and to many the wings seem still at this time.

8 THE AMERICAN NATURALIST [Vor. XL

'The difference in the rates of speed of wing-flapping on differ-

ent days is very marked. At times, and often for many successive

days, it is noticeable that, although the bodies of the fish as they

rise from under the steamer's bows are clearly and sharply defined

their supporting wings have a peculiar hazy and blurred look, with

a want of definition of outline which cannot be accounted for, for

they seem to be still. ‘Then a day will come when the fish, still

fleeing in front of the ship, will move their wings less rapidly and

their motion will become plainly visible. ‘There are still many

lookers-on who cannot pick it up, but for the rest the aéroplane

theory is exploded for ever, and when next the swifter-moving

wings are seen with the eye of knowledge the wonder is that there

had been any difficulty. The haze and blur are exactly what

should have been looked for under the cireumstances.

We have all of us watched sea-gulls soaring quietly in a certain

direction, but obliged to flap when they turn away, the vigor of

the flapping varying more or less regularly with the direction in

which they meet the wind. It is more than probable that the

change of wing-speed of the fish varies for similar reasons in degree

of rapidity, soaring being, as I have endeavored to show, quite

out of the question. From whatever cause, it certainly does so

vary.

A curious thing about the “ vibration" periods is that they seem

to offer fleeting glimpses of a satisfactory wing; for a moment,

now and again, the wings have outlines and edges, and will also

occasionally return a sun-glare to the eye from their wet glassy

surfaces, such as might be expected from them when not whirring.

Such a glare is also now and then momentarily to be seen when a

fish ceases flying, and just before it strikes the water, if it be in

the proper position with regard to the sun. There would, of

course, be many long periods of this glare were the wings really

still.

One or two more prominent fallacies are handed on from writer

to writer, and often accepted as facts. One is that the fish are

helped in their flight by the distention of their air-bladder. If

such had any appreciable effect it would be that of impeding the

flight, for the contained air being under compression would be

denser and therefore heavier than the outside air, and the increased

"ager equ ER 5

cue ic emp D T cd

No. 469] FLYING-FISH FLIGHT 9

size of the fish would merely check its speed as a hollow bullet is

checked.

Steering-power is also denied to the fish by most naturalists.

It is, nevertheless, a matter of common seafaring knowledge that

they turn with deliberate intention. I have myself watched one

fly towards the ship, and, circling back, finish its flight in a direc-

tion straight away from the ship. It approached within a yard

or so of the side, close under where I was standing. The check

of speed on its first taking alarm was marked, and during the turn

of half a circle of about 10 or 12 feet radius which it made it could

not have been flying at a rate of more than three or four miles an

hour.

Again, they rise quite at will, though this power also is denied

by aéroplanists. With reference to this, as well as to their power

of steering, the late Earl of Pembroke, or Doctor G. H. Kingsley,

joint authors of South-Sea Bubbles, says (p. 64, 7th ed., 1895):

" Flying-fish do fly, moving their pectoral fins with extreme rapidity,

moreover, they raise and lower themselves over the tops of the

waves, and do not dip into them,. . . .I remember between Panama

and Rapa I used to see the cabin's bulls’ eyes surrounded by a

circle of scales every morning left there by flying-fish." They

were making for the light. No ingenuity can fasten this upon

“currents of air," which are credited with so many other impos-

sible feats on behalf of these fish. This habit of theirs is quite

well known, and is effected by raising themselves and steering,

pure and simple. |

Their taking a baited hook is also denied. As a matter of fact,

a baited hook is the first part of the fishing-process of the Barbados

flying-fishing fleet, with which I have been out. We had a blank

day; but, according to the animated description of the boatmen,

the struggles of the first victim bring round it swarms of sympa-

thizers (as gulls flock round a wounded companion), and these are

“raked” into the boat by the hand hoop-net, an enlarged edition of

a round shallow shrimp-net without any handle.

I have throughout this paper spoken of flying-fish generally,

for the wing-areas of all of the known kinds are to their weights

and speeds such that the impossibility of their practical use as

aéroplanes differs only in degree. —

10 THE AMERICAN NATURALIST [Vor. XL

Flying-fish put on different aspects according to the state of

air and sea. One is rather startled at times by the changes in

their methods. In oily equatorial calms, I have watched them

in numbers flying long distances with their tails in the water and

their heads and wings in the air, the body making an angle of

perhaps 30° or 40° with the horizon. ‘The wake left in the water

by the dragging tail showed, as well as I could judge, no signs of

its having been used for purposes of propulsion, even in its own

element, and it is, perhaps, simply to relieve the fish of its weight

that it is so supported when there is no fear of the wings being

caught by ruffled water; nevertheless the peculiar long lower half

of these tails specially adapts them for use as auxiliary propellers

to a fish which, with their exception is “a fish out of water"; and

it looks so like a case of natural evolution, that I feel inclined to

doubt the justice of my personal observation as to their non-use.

It would seem, from this habit, reasonable to suppose that the

fish have the power of flapping their wings at various angles, as

have birds, as ordinarily their bodies are fairly horizontal as they

fly.

The flight of these fish is often described as “graceful,” “light,”

and so on. ‘To him who believes that they soar along easily for

200 yards without further effort than a preliminary leap from

the sea, such an opinion may be a natural one.

To him who recognizes that such a leap is mechanically impos-

sible, whether or not assisted by a continuous tail-movement, or

to him, who, without thinking particularly about it, simply sees

the heavy laboring of the wings as the fish patiently whirrs along

its even, uneventful way, “graceful” and “light” are terms mis-

placed. Strenuous, persistent, plodding effort is the impression

left upon the mind, the least failure in which effort means plump-

ing into the water. One often sees this happen obviously without

intention on the fish’s part.

In conclusion, it is, I think, made clear:—

1. That flying-fish would require to have a wing-area several,

and probably many times greater, according to their weights,

than they actually possess to enable them to accomplish sailing

flight in even such a restricted form as that carried out by sailing

irds.

No. 469] FLYING-FISH FLIGHT 11

2. That we know of no parallel case in nature which would

justify the assumption that the possession by these fishes of even

such increased wing-area would of necessity enable them to sail

long distances —(a) horizontally, or (b) close to an obstruction

(the sea), or (c) in defiance of the direction of the wind; much less

all three (a), (b), and (c) combined, as they commonly fly.

3. That their common flight is exactly what is to be expected

of flyers holding, as they do, a very low wing to weight ratio —

flyers capable of and of necessity employing, extreme wing-speed.

HAvELET HOUSE

GUERNSEY, ENGLAND

CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF

THE MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD

COLLEGE. E. L. MARK, Director. No. 173

DOUBLE HENS’ EGGS

G. H. PARKER

THE presence of an additional yolk or of a second more or less

perfect egg in a hen’s egg, though not an unusual occurrence,

is rare enough to excite the attention of those interested in natural

phenomena and has been a matter of record since the time of

Aristotle. A recapitulation of the early instances of this kind

has already been given by Davaine (’61), who has also added

much to our knowledge of double eggs. The following account

contains a description of five such eggs which have come to the

writer’s notice in the past few years and present certain features

worthy of record.

Öf these eggs the first to be described was laid 26 June, 1905,

by a hen belonging to Mrs. Prince Stuart of Wood’s Hole, Mass.

I am indebted to Mr. A. S. Pearse for the opportunity of examin-

ing it. The egg was unusually large, its major axis measuring

74 mm., its minor 55 mm. In form it was not unlike a normal

egg except that the point was less certainly distinguishable from

the butt than is commonly the case. ‘The shell was almost white;

near the poles its surface was smooth, but about its equator there

was a broad band of unusual roughness. Within was a normal

shell membrane inclosing a single mass of albumen containing

two yolks. These lay one toward the butt, the other toward the

point of the egg. The one toward the butt was approximately

spheroidal with its major axis at right angles to that of the whole

egg. It measured 34 mm. by 30 mm. The yolk nearer the point

was smaller than the other one, by which it was indented on the

side away from the point. It measured 21 mm. by 27 mm., and

its major axis was also at right angles to that of the whole egg.

14 THE AMERICAN NATURALIST Von XL

Though the two yolks were in intimate contact along their applied

faces, they were organically distinct, since each possessed an

independent vitelline membrane. So far as could be judged,

they were of the same age, in that both had the appearance of

freshly laid yolks.

The second egg to be described is one that I had the privilege

` of examining through the kindness of Mr. C. C. Spratt. It had

been laid in the spring several years ago by a hen belonging to

Mrs. C. H. Gould of North Bridgton, Me. ‘The outer shell,

which was thick but otherwise normal, was much broken; its

two axes measured 54 mm. and approximately 73 mm. It was

lined with a shell membrane and its contents were lost except for

a small complete egg which it contained. ‘This measured 33 mm.

by 39 mm., and, though rather roundish in outline, it presented a

butt and a point. Its shell was thinner than usual and its whole

outer surface was granular. The inside of this shell was lined

with a shell membrane and contained dried albumen and a dried

yolk.

The three remaining eggs were laid by a hen belonging to Mr.

F. Nielson of Medford, Mass. ‘They were laid in March, 1903,

and shortly after the laying of the largest one the hen died. When

the eggs came to my hands, each had a small opening at one end.

I am therefore unable to give their exact length but in other respects

they were in excellent condition for examination. The smallest

measured 43 mm. by approximately 57 mm., the next 48 mm. by

approximately 56 mm., and the largest and last to be laid 55 mm.

by approximately 71 mm. In each instance a point and a butt

could be distinguished and the shells were of normal texture,

color, and thickness. Each shell contained a shell membrane

and a mass of albumen in which was imbedded a second smaller

egg.

These eggs were used for exhibition purposes, but I was allowed

to cut open the one of intermediate size, and the appearance of its

section face is given in the accompanying figure. It will be seen

at once that the inclosed egg is relatively large; it measured 45

mm. by 29 mm. A butt and a point could be easily distinguished

on it. The chief axis of the small egg was parallel to that of the

large one and its point and butt were just within the corresponding

o eC

No. 469] DOUBLE HENS’ EGGS 15

parts of the inclosing shell. The shell of the small egg was rather

thin; it was lined with a shell membrane and contained albumen

which had withdrawn slightly from the shell wall, probably through

shrinkage. Between the inner shell

and the membrane lining the outer

shell, was a mass of albumen, which

was slightly discolored around the

equator of the smaller egg and near

its butt by a small amount of yolk

substance. Aside from thisneither the “`

larger nor the smaller egg contained

any evidence of yolk. Fig. 1.— A double egg cut in

The internal condition of the other nun

two eggs belonging to this set couldnot 48 mm. by about 56 mm.; the

be ascertained, for the owner preferred contained albumen, that of the

to keep them in their present form. !nclosing egg showing yolk sub-

Judging, however, from what could’be figure). Beginning at the butt

seen through the small holes in their tn ege, Ben

ends, they contained relatively large the first solid line, the shell of

eggs with firm limy shells like that seen then membrane, amd eon its

in the egg that was cut. the surface of its albumen.

An examination of the five eggs thus brane, and membrane and albu-

far described and a comparison of their pe probably due to shrink-

conditions with those of other recorded

cases of double eggs, have led me to the conclusion that at least

two factors are concerned in the production of such eggs. Double-

yolk eggs like the first one described, are due in my opinion to the

simultaneous or almost simultaneous discharge of two yolks from

the ovary instead of one, these two being enveloped by albumen,

shell membrane, and shell in an essentially normal manner.

Inclosed eggs on the other hand may be the product of an en-

tirely normal ovary and may result from the abnormal action of

the oviduct, in that a yolk normally supplied by the ovary may

be abnormally covered, retained, and inclosed in another egg.

Thus two factors in the production of double eggs may be dis-

tinguished: ovarian and oviducal.

That these two factors are really independent is indicated in

several ways. First, they seem to come into play at somewhat

-- a

16 THE AMERICAN NATURALIST [Vor. XL

different seasons. The double-yolk egg described in this paper

was laid in June, and, though Bauer (’98, p. 304) and Immermann

(99, p. 7) record cases of this kind in December and Panum (’60,

p. 186) in January, the great majority of such occur during the

warmer part of the year, from May to August according to Immer-

mann (’99, p. 7) or from March to September according to Panum

(60, p. 186). The inclosed eggs on the contrary are produced

in the winter and spring. Thus the second egg described in this

paper was laid at some time in the spring and the remaining three

in March. A compilation of the published records of this kind

shows the period to extend from December to March or April.

It therefore appears that while double-yolk eggs may be laid

at any time of year, they are most abundant in summer and that

inclosed eggs, so far as the records go, are limited exclusively to

the winter and spring.

Another point in evidence of the independence of the ovarian

and oviducal factors is seen in the condition of the hen. The

laying of eggs with two yolks may become, as Landois (’78, p. 24)

declares, almost habitual with certain hens. Bartels (95, p. 143)

states that the hen that laid the double egg described by him had

often laid such eggs and Immermann (’99, p. 8) records the case

of a hen that laid such an egg about every eight days. Apparently

this is as much an organic peculiarity of certain hens as is the pro-

duction of twins by certain individuals in the human species, and,

while it may be called abnormal in that it is unusual, it is in no

sense indicative of serious organic derangement or disease. ‘The

laying of inclosed eggs, however, is often followed by serious con-

sequences to the hen. Thus the hen belonging to Mr. Nielson

died shortly after laying the last of the lot of three inclosed eggs

described in this paper, and the same fate immediately overtook

the hen that laid the two inclosed eggs described by Fritsch (’95).

Evidently the laying of such eggs indicates a more serious state

of affairs so far as the hen is concerned than the laying of double-

yolk eggs and brings out again a difference between the ovarian

and the oviducal factors.

*Inclosed eggs have been recorded as laid in winter (Chobaut, '97),

December (Philippi, '93), January (Parona e Grassi, '77), March (Collin, '94;

Féré, :02), and at Easter (Schumacher, '96).

No. 469] DOUBLE HENS’ EGGS 17

As a result of the action of these two factors, three classes of

double eggs can be distinguished: first, those whose yolks have

_ come from an abnormal ovary but have passed through a normal

oviduct; secondly, those whose yolks have come from a normal

ovary but have passed through an abnormal oviduct; and finally,

those produced by an ovary and oviduct both of which have been

abnormal in their action.

Of the first class little need be said. Although eggs with three

yolks are extremely rare, those with two are of rather common

occurrence and, as has been pointed out, they are often repeatedly

laid by a given hen without injury to herself. As Immermann

(99, p. 10) rightly observed, these eggs fall into two subclasses:

the first includes eggs in which the yolks have separate vitelline

membranes, and the second those in which the two yolks are

within one membrane. In the former the yolks were probably

discharged simultaneously from separate ovarian follicles; in the

latter both yolks very likely came from the same follicle. When

these eggs are incubated, the two embryos begin their develop-

ment together and proceed at about the same rate. In this respect -

they are in strong contrast with most inclosed eggs in which, as

in the egg described by Féré (:02, p. 349), the inclosed yolk is in

advance of the inclosing one in development. The two yolks of

double-yolk eggs are usually each of normal size and in conse-

quence induce the formation of a large egg, though the volume

of the whole is usually not more than once and a half to once and

three quarters that of a normal egg. The fact that hens can lay

such large eggs repeatedly and yet without injury to themselves,

shows that the death of the hen, which often follows the laying

of inclosed eggs, cannot be attributed merely to mechanical causes.

Under this first class of abnormalities have also been placed

eggs with yolks of unusual form, such as the apparently double-

yolk egg described by Möbius (795). Since such apparently

double or partly double yolks often arise from a rupture of the

vitelline membrane and a flowing out of yolk substance, they

cannot of course be regarded as real examples of double yolks.

Such yolk hernias may be due either to a weak vitelline membrane

or, as Davaine ('61, p. 256) has suggested, to a constricted oviduct,

but in either case they are not to be classed with true double eggs.

18 THE AMERICAN NATURALIST [Vor. XL

The second class of abnormal eggs includes those in which a

normal yolk is received by an abnormal oviduct and in consequence

becomes covered with an abnormal set of envelopes. This is

represented by eggs that are normal as to contents, form, and size,

but are contained in other larger eggs. Instances of this kind

have been described by Barnes (763; '85), Fritsch (95), Chobaut

(97), and Gruvel (:01). Very likely the second egg described by

Supino (797) belongs to this class, but the inclosed egg, though of

normal size, is said to contain an unusual yolk, indicating possi-

bly an ovarian abnormality. Here also should probably be placed

an egg recorded by Féré (:02) in which the inclosed yolk, though

apparently normal, is contained in a small amount of albumen

and what appears to be a thick egg membrane, but is without a

shell.

In most of the instances just cited, the enveloping eggs are of

two kinds. The first consists of shell, membrane, and albumen as

in the cases described by Fritsch, Chobaut, and Gruvel; and the

second possesses a yolk in addition to these parts, as in the eggs

recorded by Barnes and Supino. The exact method by which a

normal egg becomes inclosed in a second more or less complete

egg is not wholly clear; but a discussion of this question will be

deferred till the third class of eggs has been described.

In the third class of double eggs there is evidence of both ova-

rian and oviducal abnormalities. In examples of this kind the

inclosed eggs usually consist of shell and membrane containing a

mass of albumen and a small yolk, as in the cases recorded by

Vaillant (75), Parona e Grassi (77), de Man (778), Philippi

(93), Schumacher (796), Herrick (99a; '99b, p. 409), and Kunstler

et Brascassat (:01); or inclosing albumen but without a yolk, as

in the first egg described by Supino (97), and those described by

Herrick (99b, p. 410), and Gruvel (:02). In this class two types

of inclosing eggs might be expected: one with a yolk and one with-

out a yolk, but, strange to say, of the nine instances! in which the

descriptions are sufficiently full to allow this point to be ascer-

tained, the inclosing egg always consisted of shell, albumen, and

yolk. :

*Parona e Grassi (77), de Man (78), Philippi (793), Schumacher (96),

Supino, two eggs (’97), Herrick, two eggs (’99a; '99b), and Kunstler et

Brascassat (:02).

No. 469] DOUBLE HENS’ EGGS 19

Notwithstanding the fragmentary character of the second egg

described in this paper, it undoubtedly falls under the third class;

and I am also of the opinion that the three eggs from Mr. Nielson’s

hen likewise belong here. It will be remembered, however, that

of these three eggs the one that was opened presented the remark-

able feature, not hitherto recorded to my knowledge, of the absence

of yolks from both the inclosed and the inclosing egg, though

traces of yolk substance were found in the latter. These traces

lead me to believe that the inclosing egg originally contained a

yolk which, however, probably broke and almost entirely ran out

before the membrane and shell of this egg were formed.

- To explain how such inclosed eggs reach their positions, at

least two hypotheses have been put forward. According to the

first of these, which has been advocated by Davaine (’61, p. 238),

Schumacher (’96, p. 368), Herrick (’99b, p. 413), and Kunstler et

Brascassat (:01; :02), an egg after having passed by peristalsis to

the distal end of the oviduct and after having received its usual

coverings of albumen, shell membrane, and shell, is supposed to

be carried by antiperistalsis up the oviduct where it meets a second

egg, and passing down with this, becomes covered by a second

shell, and is laid. :

According to the second hypothesis, which has been advanced

by Panum (’60, p. 185), Chobaut (97), and Rabaud (:02), anti-

peristalsis plays no part in the formation of inclosed eggs, but the

egg which is to be inclosed remains in the distal part of the oviduct

instead of being laid and is there overtaken by a second egg while

the second one is still without shell. After the second egg has

enveloped the first, a shell inclosing both is laid down.

In testing these two hypotheses, the chief question is whether

or not there is any evidence for antiperistalsis. The common

occurrence of a small egg with a limy shell in the albumen of a

large one whose shell membrane is intact, seems to me inexplicable

except on the assumption of antiperistalsis. Such an egg as the

smaller one could not receive its shell except by resting some time

in the distal part of the oviduct and it could not come to lie in the

albumen of another egg whose shell membrane was not ruptured

except by passing to a region in the oviduct above that in which

the shell membrane is formed; as this region is proximal to the

20 THE AMERICAN NATURALIST [Vor. XL

shell-forming portion of the duct the operation seems to me to

necessitate antiperistalsis. It might be assumed that the inclosed

egg made its way into the albumen of the inclosing one by rup-

turing the shell membrane of the latter just as that egg reached

the shell chamber of the oviduct. But there is no evidence in

such eggs of a ruptured membrane as this hypothesis would require

and indeed there is a case on record (Gruvel, :02, p. 73) in which

the inclosed egg apparently met the inclosing one when the shell

membranes of the latter were forming and, instead of rupturing

them, the inclosed egg remained between the inner and outer mem-

brane and never entered the albumen of the inclosing egg at all.

I therefore do not believe that the inclosed egg enters the albumen

by rupturing egg membranes but by meeting the inclosing egg by

antiperistalsis high in the oviduct and before the membranes have

been formed.

Another fact that seems to me impossible of explanation except

on the assumption of antiperistalsis is the occurrence of “ soft-

shelled” eggs in the body-cavities of fowls. This has been re-

corded by Davaine (’61, p. 241) and more recently by Landois

(99, p. 52), who states that in one instance he found four such

eggs in the body-cavity of a hen. Two of these were broken, but

two were whole and had all the appearances of normal eggs except

that they lacked shells. As there is no source for the albumen

and shell membranes of these eggs except the middle and lower

part of the oviduct and no way into the body-cavity except by the

infundibulum, I believe the conclusion inevitable that these eggs,

after the formation of their shell membranes, were moved proxi-

mally by antiperistalsis.

How antiperistalsis is excited in the oviducts is not understood.

It has been suggested that an egg of small volume might induce

such a movement and thus be returned to the upper part of the

oviduct, but, though this cannot be denied, it must be remembered

that, as Landois ('95, p. 32) has shown, small eggs such as are

often found in large ones, may be laid by hens. Moreover, as

was stated in describing inclosed eggs of the second class, eggs of

normal size are often found within the shell membranes of exces-

sively large eggs and must therefore have moved up the oviduct.

Hence the small size of an egg cannot be the only cause of anti-

peristalsis, if in fact it is at all effective in this respect.

i diced uc LC dM EL LO C i m dr acid ee E c in, tie

No. 469] DOUBLE HENS’ EGGS 21

Although in the present state of our knowledge it is impossible

to assign a cause for the setting-in of antiperistalsis, it seems to

be a process that may occur not only once but even twice in the

enveloping of ayolk. Davaine (’61, p. 237) quotes a case in which

an egg presented the very unusual condition of three separate

envelopes instead of two; these were a firm outer shell, a strong

shell membrane, and a thin shell membrane, and a second case

is given by Landois (’92, p. 34) of an egg of the red-backed shrike

(Lanius collurio L.) that had three shells one within the other.

So far as I know, the only objection that has been raised against

antiperistalsis of the oviduct has come from Rabaud (:02, p. 201),

who claims that this process could not bring two eggs together,

but would simply move them up or down the oviduct. But such

an objection is formal rather than otherwise, for it must be evident

to anyone who has watched the process as it occurs in the intes-

tines that its local character is such that eggs could easily be made

to approach in the oviduct through its means. I therefore dis-

miss this objection as without weight.

Although I believe antiperistalsis to be an all important factor

in the formation of inclosed eggs, it is in all probability some-

times greatly restricted, as is indicated by an egg described by

De Toni (’90) and the second of the two described by Supino (’97).

In both these eggs the outer surface of the inclosed shell is adher-

ent to the inner surface of the inclosing one; in other words, the

albuminous investment of the inclosed egg is imperfect, as though

the smaller egg, while resting in the shell chamber of the oviduct,

was imperfectly enveloped by the inclosing egg, whose shell on

forming adhered to the inner shell where the envelope was incom-

plete. Thus an inclosed egg might be imagined to arise after the

manner suggested by the second hypothesis already given. But

in both these instances the inclosed egg lies in the albumen of the

inclosing one and within its shell membrane, and, as already

pointed out, it is impossible to explain this position except on the

assumption of at least some slight antiperistalsis. I therefore

believe that the formation of inclosed eggs cannot take place

simply by the undue retention of one egg till it is overtaken by

another, as stated in the second Pre mens but that in all instances

some antiperistalsis occurs.

22 THE AMERICAN NATURALIST [Von. XL

Admitting antiperistalsis to be essential to the formation of

inclosed eggs, it is interesting to observe that, notwithstanding

the migrations of these eggs, they appear to retain always the

same axial relations to the oviduct that they had in the beginning.

This is clearly seen in the eggs described by Barnes (763), Chobaut

(97), Herrick (99b, p. 410), Kunstler et Brascassat (:02), and

Gruvel (:02), as well as in one of those described in this paper,

in all of which the point of the inclosed egg is in the direction of

that of the inclosing one and not toward its butt, showing that the

smaller egg has retained its original axial relations to the oviduct

even though it has moved in both directions through that tube.

Moreover, when the inclosed egg is so small that it might lie either

near the point or near the butt of the inclosing egg, it does as a

matter of fact (Barnes, ’63; Herrick, '99b, p. 410; Gruvel,

and Kunstler et Brascassat, :02) always lie near the point, showing,

since the egg moves through the oviduct point forward, that it is

the second egg that incloses the first and not the reverse.

In one respect the egg obtained from Mr. Nielson is of special

interest. As I have already stated, it contained no yolk in either

the inclosed or the inclosing albumen, though traces of yolk sub-

stance occurred in the latter near the butt of the inclosed egg.

This was due, I believe, to a ruptured and partially escaped yolk.

If this explanation is true, is it possible that the yolkless condition

of the inclosed egg is also due to the loss of its yolk? It seems

well established, however, that albumen can be formed in the

oviduct without the presence of a yolk. Possibly foreign bodies

when introduced into the oviduct by accident may induce the pro-

duction of this material. Von Nathusius (95, p. 655) has pointed

out that when a hen lays an egg, the distal portion of the oviduct

is so far rolled out that foreign bodies may adhere to it and thus

be carried well into its cavity. In this way chicken-yard refuse

and feathers, such as have been noted by Landois ('82, p. 23) in

eggs, have doubtless reached that position in the oviduct where

incorporation in a forming egg was possible. These and like

bodies may excite the oviduct to the production of albumen and

thus give rise to a core around which a shell might be secreted.

Parasites are also known to make their way into the oviduct,

and, though what have been supposed to be tapeworms in eggs

No. 469] DOUBLE HENS’ EGGS 23

have in all cases thus far carefully inquired into proved to be mere

clots of albumen or other like materials (Landois, '94), it is well

known that distomes and threadworms do sometimes occur im-

bedded in egg shells (Landois, ’78; Collin, '94). One of these

might well form a nucleus around which albumen could be depos-

ited.

But it must also be kept in mind that the ovary and the oviduct

are not such independent organs as perhaps has been implied.

Davaine (’61, p. 256) states that Claude Bernard opened a hen

that had died after laying numerous small yolkless eggs and found

the infundibulum closed and the body-cavity full of yolks. It is

therefore probable that the simple activity of the ovary may in

some indirect way excite the production of albumen in the oviduct,

and it is my opinion that many yolkless eggs such as that described

in this paper, are formed in this way rather than that they once

possessed yolks and through some accident lost them. Such

questions, however, are subjects for experimental investigation

rather than for speculation.

BIBLIOGRAPH Y

BARNES, R.

.'63. Description of a Specimen of an Ovum in Ovo. Trans. Obstet-

rical Soc. London, vol. 4, pp. 87-89, pl. 3.

BARNES, R.

'85. Ovum in Ovo: Abnormal Hen’s Egg. British Med. Jour., 1885,

vol. 2, p. 759. `

ARTELS, M.

'95. Hühner Ei mit zwei Dottern. Sitzungs-Ber. Gesellsch. naturf.

Freunde Berlin, Jahrg. 1895, No. 7, pp. 143-145.

BAUER, R. W.

'98. Ueber das Doppelei eines Haushuhnes. Biol. Centralbl., Bd.

18, No. 8, p. 304.

CHOBAUT, A.

'97. Un œuf de poule monstrueux. La Feuille d. jeunes Natural-

istes, ser. 3, ann. 27, no. 324, p. 215.

24 THE AMERICAN NATURALIST [Vor. XL

COLLIN, A.

: Ein merkwürdiger Einschlussim Hühnerei. Ornithol. Monatsber.

[Reichenow], Jahrg. 2, No. 1, pp. 3-4.

DAVAINE, C.

'61. Mémoire sur les anomalies de l'eeuf. Compt. Rend. et Mém.

Soc. Biol. Paris, sér. 3, tom. 2, pp. 183-266, pls. 1-2

De Tont, E.

'90. Un Uovo di Gallina mostruoso. Bull. Soc. Veneto-Trentina Sci.

Nat., tom. 4, no. 4, pp. 236-237.

FÉnfÉ, C.

:02. (Euf de poule contenant un autre œuf. Compt. Rend. et Mém.

Soc. Biol. Paris, tom. 54, pp. 348-349.

Fritscu, G.

'95. Hühnerei mit einem zweiten im Innern. Süzungs-Ber. Gesellsch.

natur]. Freunde Berlin, Jahrg. 1895, No. 10, pp. 202-2

GRUVEL, À.

:01. Vp hi d'un œuf à double envéloppe. Proc. Verb. Soc.

s. Nat. Bordeaux, ann. 1900-1901, pp. 20-23.

GRUVEL, A.

:02. Sur un cas spécial d'ceuf tératologique. Proc. Verb. Soc. Sci.

Phys. Nat. Bordeaux, ann. 1901-1902, pp. 72-76.

Herrick, F. H.

'99a. A Case of Egg within Egg. Science, new ser., vol. 9, no. 219,

: p. 364.

en EH.

'99b. Ovum in Ovo. Amer. Nat., vol. 33, no. 389, pp. 409-414.

IMMERMANN, F.

'99 ris Doppeleier beim Huhn. Inaugural-Dissertation, Basel;

‚43 pp, 5 Fi

ne J ., ET Bnascassar, M.

:01. Étude sur la collection d’ceufs tératologiques du Muséum. Actes

Soc. Linn. Bordeaux, ser. 6, tom. 6, pp. elxi-elxii.

KUNSTLER, J., ET BRASCASSAT,

:02. Etude d'un œuf monstrueux. La Feuille d. jeunes Natural-

istes, ser. 4, ann. 32, nos. 381-382, p. 200.

Lanpoıs, H.

"I8. Missbildungen bei Hühner-Eiern. Zool. Garten, Jahrg. 19, No.

» pp. 17-

Lawpors, H.

':82. Fremde Minschitase in Hühnereiern. Humboldt, Bd. 1, pp.

22-2

Laxpors, H.

'92. Ei des rotrückigen Würgers mit drei ineinander geschachtelten

Eischalen. 20. Jahresb. Westfälischen Prov.-Vereins f. Wiss.

und Kunst, 1891, pp. 34-35.

No. 469] DOUBLE HENS’ EGGS 25

Lanpois, H.

’94. Würmer in Hühnereiern. 22. Jahresb. Westfälischen Prov.-

Vereins f. Wiss. und Kunst, 1893-94, pp. 50-51

Lanpois, H.

'95. [Notes on Abnormal Hens’ Eggs.] 23. Jahresb. Westfälischen

Prov.-Vereins f. Wiss. und Kunst, 1894-95, pp. 32

Doo is, H.

Hühner-Eier in der freien Bauchhóhle. 27. Jahresb. West-

jälischen Prov.-Vereins f. Wiss. und Kunst, 1898-99, pp. 52-53.

Man, J. C. DE.

’78. Mededeeling over eenige Monstra, afkomstig uit de Rotter-

damsche Diergaarde. Tijdschr. Nederl. dierk. Vereen., Deel 3,

Af. 4, pp. 153-171.

Mößıvs, K.

'95. Hühner-Ei mit zwei Dottern. Sitzungs-Ber. Gesellsch. natur].

ua. Berlin, Jahrg. 1895, No. 7, p. 143.

NATHUSIUS, W.

'95. Einschluss eines Hühner-Eies, Knorpel-, Knochen-, und Binde-

gewebe enthaltend. Arch. f. mikr. Anat., Bd. 45, pp. 654-692,

Taf. 35.

Panu, P. L.

'60. Untersuchungen über die Entstehung der Missbildungen zu-

nächst in den Eiern der Vögel. Berlin; 8vo, xii--260 pp.,

12 Taf. ;

Parona, C., E Gnassr, B.

T. Sovra en Mostruositä di Uova di Gallina. Atti Soc. Ital.

ci. Nat. Milano, tom. 20, pp. 103-124, tav. 2.

PHILIPPI, R. A.

’93. Eiim Ei. Zool. Garten, Jahrg. 34, No. 2, p. 57.

RaBavp, E.

:02. [Note on Kunstler, J., et Brascassat, M., :02.] La Feuille d.

jeunes Naturalistes, sér. 4, ann. 32, nos. 381-382, pp. 201-202.

SCHUMACHER, 8.

'906. Ein Bi im Ei. Zool. Anz., Bd. 19, No. 510, pp. 366-368.

SuPrNoO, F.

'97. Deux ceufs de poule anomaux. La Feuille d. jeunes Natur-

alistes, ser. 3, ann. 27, no. 323, p. 201.

VAILLANT, L.

"75. [Un œuf de poule monstrueux.] Compt. Rend. et Mém. Soc. Biol.

Paris, sér. 6, tom. 1, p. 162.

BIOLOGICAL RELATIONS OF CERTAIN CACTI?!

W. A. CANNON

EsPECIAL interest is attached to the study of the cactus family

because it is peculiarly well adapted by habit and by structure

to withstand the trying conditions of the desert. The greatest

development of the group occurs in the arid portions of tropical

and subtropical America, but the conception which this statement

is likely to give that the cacti thrive best with a modicum of water

and live in localities that are too severe for all other desert plants

to endure, is erroneous. The cacti like other plants of the desert

are most vigorous when the water supply is adequate, and it is

by no means certain that such a form as the giant cactus (Cereus

giganteus) or the barrel cactus (Echinocactus wislizeni), as well

as the larger Opuntias, do not require a larger amount of water

than many of the large plants of other families.

However, it is also likely that no desert plants can live and

perpetuate their kind under more arid conditions than some of

the cacti. The general means by which they accomplish this are

too well known to require repetition here, but certain adaptations

to desert conditions, not so well known perhaps, may be pointed

out. The most important factor in the life relations of the des-

ert plants is unquestionably the available water supply, and the

most striking adaptations accordingly are associated with the

absorption, the storage, or the conservation of water. This rela-

tion to the water supply, either in apparent independence of it

or in intimate association with it, is met at each stage of devel-.

opment. For instance, the seeds of the giant cactus will ger-

minate in summer while lying on the top of air-dry sand and

without previous wetting. Seedlings of Opuntia versicolor are

provided with water-storage organs (Fig. 1) although such are

absent in the adult plants. The reaction of the mature plants

to a variable water supply is also noteworthy. Specimens of

! Papers from the Desert Botanical Laboratory of the Carnegie Institution,

No. 11.

28 THE AMERICAN NATURALIST ^" [Vou.XL

Opuntia engelmanni, wrinkled from the loss of water during a

long drought (Fig. 2), absorbed sufficient water within two days

following a storm to make their joints plump and smooth (Fig.

3). The giant cactus is especially adapted by the peculiar for-

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Fig. 1.— Young plants of Opuntia versicolor showing the water-storage organs —

the swollen roots — which are not present as such in the mature form,

mation of the rind to undergo without injury considerable changes

in volume which are induced by a variation in the water content

(E. S. Spalding, :05). Other adaptations, such as certain char-

acteristics of the root systems, certain peculiarities of structure

and their relation to transpiration, and the transpiration under

different conditions may be presented somewhat more fully.

Fic. 2.— Opuntia engelmanni, May 11. May 11 marked the close of a severe dry

period and the wrinkled surface of the cactus shows that it was suffering from

the drought.

30 THE AMERICAN NATURALIST [Vor. XL

Tue Roor SYSTEMS

A special study of the structure and extension of the root sys-

tems of desert plants cannot fail to be of great interest and im-

portance in contributing to a right understanding of the biology.

of these plants. Many characteristics of the desert vegetation

are without much question directly traceable to peculiarities a

the various root systems. It has been observed (Coville, '93,

p. 43) that the fairly equal spacing of desert shrubs is one of

the characteristics of their distribution. The primary cause for

this is presumably the struggle for water and their distribution

is, therefore, an expression of the mutual relationship of the root

systems. Again, frequently the form of the root is incompatible

with certain habitats,— for example a subirrigated plant would

find difficulty in growing where the subsoil is the rock-like calliche,

— and plants with such deeply penetrating roots, for instance,

are for this reason limited in their distribution. It is theoretically

possible, and so far as I have observed actually true, that those

plants that have a root system which is at once superficial and

which penetrates the ground deeply, all other things being equal,

may also have the widest choice of habitats. Certain it is that

the creosote bush, for example, which has a root system of this

character (V. M. Spalding, :04) is perhaps the most widely dis-

tributed of our desert shrubs. Although this view of the relation

of the character of the root systems to the distribution of these

plants is advanced tentatively only, the importance of it ás a

factor which must be taken into consideration in this connection

and sometime carefully studied, is very apparent.

The root system of a specimen of Echinocactus wislizeni which

was 60 cm. high and 35 em. in diameter, growing about 75 meters

north of the laboratory, was carefully exposed and the course of

its roots mapped (Fig. 4). The roots, as the figure indicates,

were branched very freely. There were three main roots which

arose from the base of the plant not far from 10 cm. from the sur-

face of the ground and which so directed their growth, and that

of the branches, that the area compassed by them was about

equally apportioned and well covered. As a rule the roots were

Fic. 3.— Opuntia engelmanni, May 14. This is the plant shown in Fig. 2. Rains

came May 10-12; the plump condition of the joints of the plant on May 14

indicates that water was absorbed promptly after the rains, and in consider-

able quantity.

32 THE AMERICAN NATURALIST [Vor. XL

slender. At a distance of 15 cm. from the plant one of the largest

of them was 7.6 mm. in diameter, and one meter from the plant

it was 4.6 mm. in diameter. The roots ran about 6 cm. below

the surface, in places which were free of stones, but when a stone

was encountered the root dipped beneath it and availed itself of

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Fic. 4.— Root system of Echinocactus wislizeni. Scale: 1 unit — 30 cm.

the better water supply to be found there. The most deeply

placed root, however, was not more than 10 em. below the surface

of the ground. ‘There are therefore two noticeable characteristics

of the root system of Echinocactus wislizeni, namely, the roots

No. 469]

BIOLOGY OF CACTI

AL.

Fre. 5.— Root system of Cereus giganteus. Scale: 1 unit = 10 em.

34 THE AMERICAN NATURALIST [Vor. XL

are slender en their entire course and they are super-

ficially placed.

The roots of Cereus giganteus, on the other hand, in form and

position, and perhaps in extent and branching also, are very dif-

ferent from those of Echinocactus. Fig. 5 represents the root

system of a Cereus giganteus, about one meter high, which was

growing 200 meters west of the Echinocactus just described. Four

main roots were observed to arise from the base of the plant. At

first they were relatively heavy, from 2 to 4 cm. in diameter at

the proximal ends, but they became smaller very rapidly as the

distance from the plant increased —in a manner much as is

indicated by A of the figure. Very soon after leaving the plant

the roots branched. One branch, whose later history could not be

traced, struck directly downwards, and. the other took a more or

less horizontal course. The latter branched at intervals, although

perhaps not so frequently as those of Echinocactus, and extended,

in one instance at least, over one meter from the plant's base.

How much farther the root reached could not be learned because

of its fragility and the small size of the distal branches. The

superficial portion of the root system of Cereus giganteus was

more deeply placed than were. the roots of Echinocactus, and

owing to the fact that these parts were not so richly branched,

the groünd included by them was not so thoroughly covered.

However, in' one characteristic, which is of interest to note but

whose significance I have not investigated, the superficial roots of

the two forms are alike, namely, the longer roots and the greatest

number of roots are situated on the uphill side of the respective

plants. This peculiarity is shown- in- the two figures. In Fig. 4

the uphill des is to Fe right, and in Fig. 5 itJis’at the top of the

sketch.,

CERTAIN STRUCTURAL FEATURES

Perhaps the correlation of structure and function is nowhere

more patent than in the peculiar transpiration-controlling and

transpiration-promoting tissues, and the rate of transpiration in

certain cacti. As is well known, the cacti are well adapted struc-

turally, laying aside for the moment the matter of water storage,

No. 469]

to retain water for long periods.

( XJ ur

2x M )

a specimen of Cereus

giganteus must ordinari-

ly retain water in this

locality, the following

may be suggested. Cal-

culations based upon the

known average water con-

tent of these cacti, on the

estimated spread of the

root system, and on the

average rainfall at this

place indicate that ap-

proximately two years’

rainfall, assuming the

rainfall to be normal

each year, 11.74 in., -are

required to supply

cactus 15 feet high with

an amount of water

BIOLOGY OF CACTI

Fic. 6.— Echinocactus wislizeni.

As an illustration of how long

A portion of the

cortex showing chlorenchyma with large inter-

cellular spaces.

The section was made parallel

to the surface.

equal to what it usually contains. The necessity of husbanding

This section was parallel to the surface.

the water so hard-gained is even

more apparent when the relation

' of the normal rainfall to the usual

evaporation is taken into account.

As has been pointed out (Coville

and MacDougal, :03, p. 27) the

annual evaporation is 7.7 times

the rainfall. This is the normal

ratio, but when the precipitation

is below average, as in 1904

(when it was 75 percent normal)

the disparity is even greater (Can-

non, :05b).

Although, as mentioned above,

the structural adaptations for the

retention of water are well known,

reference should here be made

to the special adaptations found in Echinocactus wislizeni, par-

36 THE AMERICAN NATURALIST [Vor. XL

ticularly on account of the small rate of transpiration which

was demonstrated in this plant. Echinocactus has a heavy outer

| membrane which is cuticularized

(Figs. 9, 10). The stomata are

peculiarly fitted to guard well a

too rapid loss of water, and they

have a somewhat complicated

structure. The stoma as charac-

teristic of many xerophytic plants,

is sunken below the general sur-

face of the stem, and from it in

Echinocactus a tube, divisible in-

to two portions of separate func-

Fic. 8. Waagen wislizeni. Surface |. .

vius chun tion, leads deeply into the outer

portion of the cortexand becomes

the peripheral portion of the extensive intercellular aérating sys-

tem of the plant. The substomal tube, really trachea, is shown

schematically in Fig. 11. The outer portion, which is heavily

shaded in the sketch, is cuticu-

larized throughout its course in

the sclerenchymatous tissue (Fig. p

10) of the cortex, and in this part Q

it acts merely as a tube for the a

conduction of gases. Beneath

the supporting tissue the tube

enters the chlorenchyma and its

wall is no longer cuticularized; it

here functions as the substomal

chamber proper.

It is of interest to contrast

with this permanent structure a p, 9.— Echinocactus lit. Bio:

form of stoma and sort of adjoin- mata and substomal canal which passes

ing tissue which are a part of tan Peer T ARE:

evanescent organs, and which also — *"ehyme (Fig.

appear to have somewhat different functions. I have reference

to the stomata of the leaves of Opuntia versicolor. The perma-

nent stomata of this Opuntia closely resemble those of Echino-

cactus but the temporary stomata, those of the leaves, are very

Be Fr i Bi E k

RO ED REIT NE ERS CEU

No. 469]

different (Figs. 12-14).

BIOLOGY OF CACTI

These stomata are superficially {placed

Fig. 10.— Echinocactus wislizeni.

tissue

and they open directly into the substomal

chamber (Fig. 12). The substomal canal

of the permanent organ, therefore is lack-

ing. Associated with thisform of stoma is

the absence of asclerenchymatous support-

ing tissue, and, consequently, the exten-

sion of the chlorenchyma to the epidermis.

The heavy outer epidermal wall of the

older portions of Echinocactus is here

replaced by a delicate one. In connec-

tion with this structure of the leaves of

Opuntia appears their function of pro-

moting transpiration, and presumably

the respiratory activities as well, and in

this they render it an important service,

as will be apparent from the results of

the transpiration studies.

Same as Fig. 9, to show character of supporting

Fic. 11.— ee:

enden

sketch Be the rela-

tions of the substomal

chyma is represented by a

lighter wa

TRANSPIRATION OF CEREUS AND ECHINOCACTUS

In all of Hie ne on the transpiration of cacti which were

method (Cannon :05a), described

elsewhere, was anod: A few, however, which will be pointed

38 THE AMERICAN NATURALIST [Vor. XL

out later, were done in the laboratory by weighing in a manner

Fie. 12.— Opuntia versicolor. Cross section of a leaf showing two stomata, one

of which was cut in two at right angles to the guard cells and the other parallel

to and to one side of them. The confluent substomal chamber is shown.

section is to be contrasted with Fig. 13.

to be described. This change in method was made necessary

on account of the high relative humidity prevailing at the time.

Fic. 13.— Opuntia versicolor. Substomal canal and partly developed

supporting tissue of a young stem.

No. 469] BIOLOGY OF CACTI 39

Experiment No. 1. Cereus giganteus

Percent of

Time Saturation Temperature Milligrams

9:27 A. M. 42.0 94? F. 67.5!

10:82 A WC ; 48.5 105? F. 106.0

The cactus was located in the shade of a palo verde (Parkin-

sonia microphylla) on a dry mountain-side not far above the bed

of Salvino Canyon, 18 miles east of the Laboratory. Higher

Fig. 14.— Opuntia versicolor. Cross section of a leaf to illustrate its delicate struc-

ture. >

on the same slope were many other giant cacti of large size, and

other typical desert plants such as Encelia jarinosa, Fouquieria

splendens, as well as other species of cacti.

1 The first amount in each case is the absolute humidity of the atmosphere

of the bell glass when the experiment begins. The second amount is the

absolute humidity at the close of the experiment. The difference between

the two is the amount transpired.

40 THE AMERICAN NATURALIST [Vor. XL

The transpiration of the cactus was taken September 9, and

as the high relative humidity at the beginning of the experiment

shows, the effects of the rains of August were still manifest. The

rate which is 0.2 milligrams per minute for 100 sq. cm. of tran-

spiring surface, may be considered a high one, since without ex-

ception the greatest rate of transpiration of all the plants, whose

seasonal variation in rate has been observed, has been after or

at the time of the summer rains.

Experiment 2. Echinocactus wislizent

Percent of Amount in

Time Saturation Temperature Milligrams

10: 28 a. M. 32:5 82° F. 36.0

2: 05 P. M. 35.5 91° F. 51.0

This experiment took place on March 19, at the Desert Botan-

ical Laboratory.

The rate of transpiration of the entire plant per hour is 3.4

milligrams.

On September 3 the experiment was repeated when the fol-

lowing data were derived :—

Experiment 3. Echinocactus wislizeni

Percent of

Amount in

Time Saturation Temperature Milligrams

12: 24 ». M. 35 104? F. á 60

3: 14 P. M. 45 109? F. 89

The rate for the entire plant is 9.6 milligrams per hour.

This specimen of Echinocactus is growing on a westerly slope

on the Laboratory Mountain. In its vicinity are found a few

giant cacti and Encelia jarinosa, Lycium sp., and Parkinsonia

microphylla. Because of the desirability of preserving this speci-

men the surface was not computed and therefore the rate cannot

be compared directly with that of Cereus giganteus as given in the

preceding experiment. However, it happened that the two cacti

were of nearly the same size, — 10 cm. in height,— and a gen-

eral comparison between the two can be made. The rate of

No. 469] BIOLOGY OF CACTI 41

Cereus per hour was approximately 33 milligrams while that of

Echinocactus on September 3 was 9.6 milligrams. Whether

this difference in the rate is constant for the two genera, or is

attributable to other and unknown causes aside from the rela-

tively slight difference in surface, is not known.

TRANSPIRATION OF Opuntia versicolor

A specimen of Opuntia versicolor about 20 cm. high, growing

near the laboratory building, was studied at various times during

the dry portions of the year (1904), namely, in March, April,

June, and July. The observations indicate that the reaction of

Opuntia to water is very different from that of other desert plants,

such for instance as Covillea tridentata, Encelia farinosa, or Fou-

quieria splendens (Cannon, :05a, p. 404), suggesting a unique

position among its associates and an important factor among

the varied ones that brought about the present distribution of the

group to which it belongs.

As has been shown in another place, the transpiration of Fou-

quieria splendens, as well as that of other desert plants and plants

of more humid regions (Burgerstein, :04), under certain con-

ditions increases with an addition to the available water supply

(see Cannon, :05b; V. M. Spalding, :04, :05). Thus after

rains, but before leaves appeared, the rate of transpiration of

Fouquieria splendens increased about three fold; after leaves

had been formed and while they were developing the rate was

relatively very great. A similar condition was likewise observed

in Encelia farinosa, Covillea tridentata, and in other plants. In

Opuntia versicolor, however (see Figs. 2, 3), and probably in

other Opuntias the response to the rains is indeed also positive

but in a very different way. The cactus absorbs water greedily,

and as a consequence it at once increases in size, and its tissues

become turgid. But, so far as I observed, the rate of transpira-

tion did not increase proportionally. Indeed, laboratory experi-

ments, in which a small specimen of O. versicolor was attached

to a potometer by a long delicate tube so that the cactus could

be weighed at intervals at the same time that its rate of absorp-

tion was being recorded, showed very clearly that under such

42 THE AMERICAN NATURALIST [Vor. XL

conditions the cactus may absorb water much faster than it gives

it up by transpiration.

It should be noted that the specimens of cactus which were

experimented upon both in the field: and in the laboratory did

not have an adequate water supply at their disposal previous to

the times of the experiments. As a general thing not until some

time has passed after the water has been absorbed, does new

growth appear with its embryonic structure and its evanescent

leaves and then only does the rate of transpiration become greatly

increased. During the periods of drought the plants make but

little new tissue. These peculiarities of Opuntia versicolor were

observed repeatedly and will be presented in the succeeding

résumé of representative experiments.

The transpiration of Opuntia versicolor,—an entire plant,—

was as follows: —

March 25 . i i A 51.0 milligrams in one hour

March 6 . P i ob aM" RES dr n

Awl 20s A a NM

June 30 . ; i : 27.5 «6 D A a

July 4 : 26.1 “ co u “

During the period from March to July the rainfall was unusu-

ally small and the cactus had an insufficient supply of water.

The rates of March, April, and June, therefore, represent the

transpiratory activities of the plant in times of drought. At

various times in the midst of the dry seasons Fouquieria, Covil-

lea, and other plants had been irrigated and the effects on their

transpiration were recorded (Cannon, :05b). To learn how an

increase in the water supply of Opuntia versicolor would influence

its rate, as well as to learn how the rate under such circumstances

would compare with that during dry conditions, it, also, was irri-

gated. On June 27, which was a time of drought, nine gallons

of water were poured slowly on the ground at the base of the

cactus, but it did not show by an accelerated rate (see the rate

of July 4, above) that it had absorbed any of the water. That it

had really done so, however, was indicated by the fact that the

plant had become rigid by the increased turgescence of its tissues.

Unfortunately a small branch was broken from the plant after this experi-

ment so that the winter and the summer rates are not comparable.

No. 469] BIOLOGY OF CACTI 43

The transpiring surface of the Opuntia was not estimated,

so that its rate cannot be compared directly with the rate of other

cacti or plants of other families although this, perhaps, is of minor

consequence. The important fact was established that the plant

does transpire measurable amounts of water even in the driest

times and that it absorbs water quite out of proportion to its rate

of transpiration.

I wish now to call attention to a phase of the biology of Opun-

tia versicolor which is also of great importance in the economy

of the plant but which has hitherto received little emphasis,

namely, to the röle which the leaves play in transpiration.

On August 18 the polymeter apparatus (Cannon, :05a, Fig. 4)

was adjusted to take the transpiration of a branch of the cactus

which bore leaves and which was situated a few meters north of

the laboratory building. The data derived from this experiment

are as follows:—

Experiment 4. Transpiration of Leaves of Opuntia versicolor

Percent of Amount in

Time Saturation Temperature Milligrams

2:20 P. M. 40 UT Ff, i

2:30 P. M. 59 98? F. 101.

The branch transpired at the rate of 234 milligrams in one

hour, or 0.91 milligrams per minute for 100 sq. cm. of transpir-

ing surface.

As soon as the experiment was finished the surface to the stem

was coated with vaseline and the experiment was repeated. The

following, therefore, is the transpiration of the leaves only.

Percent of |J Amount in

Time Saturation Temperature Milligrams

2:42 P. M. 97? F.

2:52 P. M. 52.0 100? F. 87.

The rate per hour for the leaves of the branch is 108 milli-

grams, or 0.42 milligrams a minute for 100 sq. em. of surface.

The surface of the stem alone was estimated at 331 sq. cm.;

that of the leaves at 97 sq. cm. ‘Therefore with somewhat less

44 THE AMERICAN NATURALIST [Vor. XL

than one fourth the entire transpiring surface, the leaves alone

transpired nearly one half the whole amount.

The high humidity at this time was unfavorable to the further

use of the polymeter method so that the experiments upon the

transpiration of the leaves of the cactus were continued with a

special weighing apparatus in its stead. Since the results of all

of these experiments were essentially alike, I shall refer to one of

them only.

A branch of Opuntia versicolor with leaves was placed in a

bottle containing water which was so arranged, with a capillary

tube as well as the branch fastened in the stopper, that the air

could enter and maintain a pressure within uniform with that of

the room, while only an inappreciable quantity of vapor escaped.

In one hour, 2 : 15 to 3 : 15 P. m., the branch lost 180 milligrams

in weight. The stem was then coated with vaseline and in one

hour, 3 : 30 to 4 : 30 r. w., the loss of weight was 100 milligrams,

which was, of course, the transpiration of the leaves only.

There were 69 leaves on the branch whose entire surface was

estimated at 55 sq. cm. The surface of the stem alone was 65

sq. cm. ‘Therefore the leaves had about 45 percent of the entire

transpiring surface and they gave off about 55 percent of the

entire amount transpired.

SUMMARY AND CONCLUSIONS

The leading points in this paper and the conclusions may be

briefly stated in the following summary.

1. The root systems of Cereus giganteus and of Echinocactus

wislizeni which were studied and mapped, present characteristic

differences. The root system of Cereus is in part superficial

and in part deeply placed. The root system of Echinocactus is

superficial only. There appears to be a relation between the char-

acter of the root systems of these plants and that of the habitats

in which they naturally occur. For example, the form and the

extension of the roots of Cereus inhibit its occurrence in localities

where the underlying formation is of such nature that they cannot

reach the usual or needful depth. We accordingly find the plant

on rocky mountains, or where the soil is deep, but in this locality

No. 469] BIOLOGY OF CACTI 45

it does not grow at all, or rarely, on the mesa where the rock-like

calliche forms a thick and nearly impenetrable stratum which

reaches almost to the surface. However, it may not be wholly

a problem of anchorage, since the morphological condition may

be associated with a physiological one, as for instance, subirriga-

tion or proper drainage which may be indispensable factors in

its water relations. Although the character of the root system

may thus be closely connected with the character of the habitat,

certain features in the local distribution indicate that it cannot

be too narrowly insisted upon. For example, Cereus giganteus

avoids northern slopes, although to all outward appearances the

structure and the water supply may be quite the same as on the

other sides.

Echinocactus presents quite a different condition of affairs.

The plant does not require unusual protection against lateral

stresses. It grows most abundantly in this locality on the mesa

where the soil is shallow. The roots are so placed that they can

neither afford safe anchorage for a tall plant, nor absorb water

at the water level. There is therefore a direct relation between

the character of the plant and that of the root system, on the

one hand, and the character of the root system and that of the

habitat, on the other. It should also be noted that the roots

of Echinocactus, which are very shallowly placed, permit the

plant to derive benefit from relatively small rains, but, by the

same token, that they prevent it from getting water other than

what falls on the area included by them.

2. The striking disproportion between absorption and tran-

spiration, which was observed in Opuntia versicolor, is thought

to be of great importance in accounting for the distribution of

the plant (and perhaps of the family) in those parts where evap-

oration greatly exceeds precipitation.

A low rate of transpiration was demonstrated in Opuntia

versicolor and Echinocactus wislizeni during periods of prolonged

drought. At the time of the summer rains the rate was greatly

increased and in all instances the increase was associated with

the renewal of growth.

4. A direct relation was observed between structure and tran-

spiration. The mature portions of Echinocactus and of Opuntia

46 THE AMERICAN NATURALIST [Vor. XL

versicolor are suited by the heavy outer epidermal wall, which

is cuticularized, as well as by the stomata of peculiar structure,

to resist rapid loss of water. This is the type of structure that is

to be found during the periods of drought. ‘The embryonic por-

tions of these cacti, and the evanescent organs, in which are

included the leaves of Opuntia, are well adapted to promote tran-

spiration. This is accomplished in the embryonic tissues by a

thin epidermal wall and by the undifferentiated portions of the

outer part of the cortex by which a rapid transfer of water is possi-

ble. The substomal tube functions also throughout its entire

length as the substomal chamber. In the leaves of Opuntia not

only is the epidermal wall delicate, but the outer cortex is never

differentiated into sclerenchyma and chlorenchyma and there is

no substomal canal. Such is the structure of the tissues at the

times when the rate of transpiration is most active.

5. The leaves of Opuntia versicolor play an important röle

in transpiration. In one instance with somewhat less than one

fourth the entire transpiring surface the leaves transpired nearly

one half the whole amount. In another instance about 45 per-

cent of the entire transpiring surface was foliar and the leaves

transpired about 55 percent of the total amount. |

DESERT. BOTANICAL LABORATORY

OF THE CARNEGIE INSTITUTION

No. 469] BIOLOGY OF CACTI 47

LITERATURE

BURGERSTEIN.

704. Transpiration der Pflanzen. Jena.

Cannon, W. A.

:05a. A New Method of Measuring the Transpiration of Plants in Place.

Bull. Torrey Bot. Club, vol. 32, p. 515

Cannon, W. A.

:05b. On the Transpiration of Fouquieria splendens. Bull. Torrey

Bot. Club, vol. 32, p. 397.

CoVILLE, E. V.

'93. Botany of the Death Valley Expedition. Contr. U. S. Nat. Herb.,

4, p. 43

CoviLLE, F. V., anb MacDovaat, D. T.

:03. The Desert Botanical Laboratory. Public. Carnegie Inst., Wash-

ington.

PLOTA, E. S.

Mechanical Adjustment of the Suguaro (Cereus giganteus) to

Varying Quantities of Stored Water. Bot. Gaz., vol. 32, p. 57.

SPALDING, V. M.

:04. The Creosote Bush (Covillea tridentata) in its Relation to Water

Supply. Bot. Gaz., vol. 38, p. 122, 7 figs.

SPALDING, V.

:05. Soil Water! in Relation to Transpiration. Torreya, vol. 5, p. 25.

CONTRIBUTIONS TO THE PHYSIOLOGY AND

BIOLOGY OF THE DUGONG

H. DEXLER AND L. FREUND

THE accounts of the habits of the dugong that have hitherto

been brought to the notice of naturalists are really limited to a

detailed description by Klunzinger, who as surgeon on the ** Koseir "

in the sixties, collected these accounts of the dugong of the Red

Sea from the Bedouins. 'The account in Brehm's Tierleben is

taken from him. ‘The few who before or after him have had to

do with the subject, have added but little that was new. For

this reason we are warranted in publishing some very recent

observations based on the field notes of one of us (Dexler). In

1901, through the generous support of the Gesellschaft zur Fór-

derung deutscher Wissenschaft, Kunst, und Literatur in Bóhmen,

Dexler was enabled to make a visit of several months to the Coral

Sea, and there to attend personally to the capture of the dugong.

Incidentally, also, the rare opportunity was afforded of observing

minutely for forty-eight hours the habits of a captive dugong, and

to investigate in life what has hitherto been impossible for us to

find out in the case of this animal.

'The low flat coast of East Australia is a favorite haunt of the

dugong. Here are broad, shallow bays choked with sand and

covered with water at low tide, and connected with the outer

ocean by numerous channels and passages. Here is the plant-

bearing sea bottom on which occur the so called “dugong grasses”

that constitute the food of the dugong. These bottoms are the

chosen pasture of the dugong and it is one of their permanent

occupants, being directly dependent for sustenance upon places

of this sort. Wherever there are these conditions, to which must

be added sea water and a particular temperature, there the dugong

will be found as all observers agree (Ruppel, Klunzinger, Finsch,

Semon). Sea water is its native element and it is questionable

if it occurs at all in brackish water at the mouths of rivers, as is

50 THE AMERICAN NATURALIST [Vor. XL

maintained by many, e. g., Brown. But as Finsch has stated,

observations on this point are lacking, and we ourselves observed

nothing of the sort. It is not known by the old Queensland dugong

fishers to enter brackish water, and that it seeks the fresh water

of the river itself is out of the question.

During the day the dugong remains in the deeper waters of

the outer ocean and only at night comes in through the channels

previously mentioned to feed in the bay. This observation is

corroborated by those of Klunzinger in the Red Sea, and by the

statements of Semon and Finsch. With regard to its appear-

ance at night, Klunzinger makes a noteworthy statement based

on the accounts of the Bedouins. According to them the dugong

is recognized at night not only by its "blow" and by the phos-

phorescence of the disturbed water, but also, they asserted, by

three shining spots on the back, a fact of which he was repeat-

edly assured but which he found it difficult to believe. Krauss

attributed this to the luminosity of the sea, but by Brehm it is

explained as due to the sparkling in three places of the water

that is disturbed in swimming, and thus made luminous. These

three places would correspond well to the rounded ripples that

would be made by the head, the middle of the back, and the cau-

dal fin. Langkavel also cites Klunzinger's statement. No such

phenomenon was observed in the Australian waters, a fact that

may have been in part due to the slight degree of phosphores-

cence of the surface water at that time of the year (the Australian

winter). However, in spite of the bright light of the tropical sea,

it is highly probable that this is a faulty observation, and untrue

of the dugong. For as it swims, its head first appears above

water to take breath, rarely the back follows, while the tail is

never shown. These movements might very well produce a

more or less clear flashing when the water is strongly phosphor-

escent, but it would seem quite as impossible to identify the ani-

mal by this as to tell it by the noise it makes in breathing. Dexler

hunted the animals in waters inhabited by both dugongs and

dolphins, and in the tropical nights made careful observations

for many hours while lying in wait at the nets in their pursuit.

At no time, however, was it possible to distinguish the two by their

resounding "blow" though often they were extremely near at

No. 469] BIOLOGY OF THE DUGONG 51

hand. Moreover, the blackfish hunters were questioned in regard

to this point, and although they are extraordinarily expert in what-

ever has to do with the pursuit of their quarry, they were unable

to distinguish between the sounds produced by the breath of these

animals. :

It is well known that the movements of the dugong in swim-

ming are slow and clumsy (Klunzinger and Finsch). "Thus late

one evening Dexler observed from his boat, six dugongs that

lazily broke water scarcely ten meters away, and with a forward

roling movement disappeared again. As a rule, only the nasal

portion of the head came above water in taking breath as Ruppel

also has observed ; but Ruppel and Semon likewise agree in

stating that very rarely the anterior part of the body or the entire

head may appear.

Before proceeding to describe certain peculiarities of biological

interest, we may add the important observations made on a

captive live dugong that have furnished the basis for the system-

atic treatment of the biological material to follow. More partic-

ular details as to capture will also be given shortly.

On one occasion when the nets were examined, there were

found in them a large ray, an ocean-butterfly, and a dugong

whose tail had become entangled in the net, though otherwise

the animal was able to move freely. This might be called very

unusual, for the animals generally strike the net headfirst, or

with one of the flippers, getting entangled, and while hanging in

the net they thrash and roll about until they are completely en-

tangled by the cords. The heavy net is thus drawn together

into a solid mass and the dugong, no longer able to raise it in

order to come to the surface for breath, is drowned. . In the

present case, as the net was tightly drawn together, it could not

be pulled up on the spot, and it was decided to drag the whole

thing out onto the shore, with the captive in tow. The fast

cutter had some difficulty in pulling the animal, but despite its

tremendous struggles it was towed along after the boat, tail first

in the gurgling wake. Twice the boat was stopped in order to

allow the exhausted bull to obtain air, and on these occasions it

became very excited and unmanageable. It kept constantly try-

ing to dive, jerking its arched body into the deep, and when it

52 THE AMERICAN NATURALIST [Vor. XL

felt the pull on its tail it rolled over and over on its long axis two

or three times. Repeatedly during these movements, it voided

gaseous and solid excrement which diffused the characteristic

odor of the dugong. The captive came up to breathe at intervals

of from 14 to 42 seconds, exhaled with a long and forcible “blow”

and inhaled with less noise and more quickly. Then the diving

and rolling were repeated.

With the flood tide the boat was brought over the bar to the

mouth of the Wallumkreek and there anchored. Here in the

shallow water the animal became for the first time somewhat

quiet after the people had withdrawn, but when the dingies put

off from land again and approached it, straightway the diving

and struggling began anew. From this it seemed that it was

not so much the sight of the approaching boats as it was the

sound that acted upon the animal’s consciousness. If a black

cloth or a piece of white canvas were waved above its head, the

animal was not visibly disturbed or only rarely. But if one

stamped on the deck then immediately it thrust its nose into the

sand in a reflex diving or escaping movement.

It was a simple matter to secure the dugong, for the helpless

animal had hardly more than its great weight with which to oppose

its capture. A strong line was soon tied about its tail and made

fast to the shore, and the dugong was then rolled out of the net

into the water. There it appeared to feel better and began at

once to thrash clumsily about, and tried to hide underneath the

cutter. However, the strain on the line soon relaxed and with

but slight exertion the dugong could be dragged into shallow

water. By this time it put its snout above water for breath

at intervals of from 17 to 65 seconds and breathed in the manner

above described. If anyone spoke, or struck the tiller, or rattled

the anchor chain, or made any other noise, the dugong started

off violently and tried to dive deeper with a movement like that of

the dolphins that roll head foremost over the surface of the water.

In these attempts the animal repeatedly struck the sand bottom

with considerable force. As soon as the line drew taut and the

dugong felt the pull, it at once executed those remarkable rapid

revolutions on the long axis of its body so that the line began to

crack. Whenthe noise ceased, the dugong soon became quiet and

No. 469] BIOLOGY OF THE DUGONG 53

lay motionless at the bottom, resigned to its fate. The intervals

between breaths also became longer; at first they were from 43

to 60 seconds, then later, from 100 to 120 seconds apart. The

following intervals were particularly noted: 104, 43, 60, 58, 95,

45, 105, 145, 85, 52, 50, 56, 120, and 85 seconds. The longest

interval was 145 seconds though of course it must be kept in mind

that in this case the animal was living under abnormal conditions,

of which it must have been sensible, despite its partial freedom.

The exhaled air had the same aromatic odor that is peculiar to the

flesh, the excreta, the fat, and the steam from the boiling meat.

Thus the captive was studied for a number of hours, though

but little else was brought out, for the radius of movement of

which it availed itself was very small. Such observations as were

made, however, were concerned almost entirely with the breath-

ing. If one struck the animal with the tiller, it took each stroke

with a slight shudder of the entire body. A more delicate sensi-

tiveness of the skin could be made out at the corners of the mouth

only. If one touched this region with the thumb, the dugong -

suddenly raised its head a hand’s breadth from the bottom.

At evening the animal was rolled up onto the shore. During

this process it thrashed about but little and allowed itself to be

borne to land as quietly as a barrel. Not until it was choked did

it repeat the tremendous strokes with the tail; at other times it

moved neither the hinder part of the body nor the flippers. ‘The

latter were held against the breast, but if they were pulled away

from the body, they remained in that position. For forty-eight

hours it lay motionless. Its death was easy, for it was asphyxi-

ated by quickly thrusting two gun wads into the nostrils during an

inhalation. It raised its head, gave three mighty strokes with its

tail and expired.

After this description, necessitated by the nature of the case,

the biological details will again be systematically discussed. A

little has already been said in regard to the manner of inspiration

and expiration. Both processes take place out of water and ex-

clusively through the nose. When the captured dugong was

asphyxiated by closing its nostrils, it made no attempt to open

and breathe through its mouth. These conditions in the dugong,

it is interesting to observe, correspond exactly to those found

54 THE AMERICAN NATURALIST [Vor. XL

elsewhere in which the epiglottis is behind the velum or in front

of it, and thus does not permit of a supplementary breathing

through the mouth also (see Boenninghaus, :03, p. 84). Still, a

similar topographical relation of the parts in question does not

correspond to similar physiological phenomena, since in the

Sirenia the velum palatinum and the epiglottis are very short

(dugong, Owen, ’38, p. 36; manatee, Waldeyer, ’86, p. 245;

Murie, ’70, p. 178).

The dugong takes breath quickly, closes its nostrils, and sinks

into the water. The closing results from the fact that the base

of the nostril is raised as a slight eminence and pressed tightly

against the top. It is interesting to observe that this procedure

was also kept up while the animal was lying on the shore, and

after each inspiration the nostrils were fast closed until the next

breath was taken. According to Finsch, the closing of the nos-

tril takes place through the action of a muscle which he does

not indicate further. Ruppel (34, p. 101) makes the incorrect

statement that the nostrils can be hermetically closed by valves

opening inwards and this fallacy is repeated by Brandt (46—'69,

p. 272). It is worthy of note that Turner (’94, pp. 319, 322,

326) found in the embryo and in the head of an adult dugong,

valves (“ valve-like flap," “plug-like valve"). No trace of such

a valve can be demonstrated. The same structure, it has been

claimed, has been found in the manatee. Brandt has previously

asserted that in the Sirenia “aperturae nasales valvulis clau-

dendae esse." Garrod (77, p. 139) plainly speaks of a “flap

valve" which forms the base of the nasal passage during the act

of breathing but rises and completely closes the nostrils when it

is shut. Likewise Brown (78, p. 292), Chapman (775, p. 461),

Crane (81, p. 457), and Noack ('87, p. 297) speak of a valve.

Murie ('80, p. 32) had already rejected Garrod's statement and

described the arrangement in the manatee as similar to that in

the dugong, that is, that the base of the nostril is raised by con-

traction of a circular muscle and the opening is thus closed and

that a free valve is out of the question.

In expiration there is a perceptible sound, that has been described

above as a loud, long “blow.” Klunzinger calls it a puff, Finsch

a breath and a puff. Semon speaks of it as a singular hollow puff.

Moreover, it is not accompanied by a discharge of vapor.

No. 469] BIOLOGY OF THE DUGONG 55

The increase in the length of the intervals between breaths,

given above, is of interest. It is of course quite possible that

the conditions of living and of breathing incident to the animal's

long period of captivity were extremely abnormal, so that it is

difficult to learn from them precisely the normal conditions.

Nevertheless, we cannot be far wrong if we take as the average

time between breaths a minute or a trifle less. The accounts of

writers show great disparity on this point. Ruppel states that

the dugongs come to the surface about once a minute. Accord-

ing to Klunzinger they do so every ten minutes and always about

four times. Semon observed a large male that came up at inter-

vals of from three to five minutes, and Finsch agrees as to these

longer intervals. However that may be, it should be observed

that the longest interval between breaths noted by us did not

exceed two and a half minutes.

'The dugongs, as above noted, feed chiefly by night and the

same is also true of the manatee. To be sure, Noack ('87, p.

300) writes that they eat all day long without interruption, though

Brown (778, p. 295) had previously shown that as with nocturnal

animals in general, they appear to feed at night only (see also

Murie, '80, p. 24). The food and the feeding habits of the dugong

have hitherto received very meager treatment. The animals lie,

it appears, directly on the sea bottom, and with their thick lips

graze leisurely upon the seaweeds (sea alge, according to Ruppel)

that grow on the rocks or the sea floor, or they tear them from

the bottom. Klunzinger speaks of sea plants, phanerogams

(Niades). According to Finsch and Semon it is chiefly sea grasses

and species of Fucus, according to Fairholme, “grass-like sea-

weeds," that constitute the food supply. But it may be stated

that the food of the dugong does not consist of the thick, dark

brown seaweeds floating up free from the bottom, but rather of

the two green phanerogamous plants which were present in the

stomachs of all the dugongs killed, unmixed with any other vege-

table remains. The dugong fishermen employed by Dexler paid

no attention to the beds of thick, dark brown seaweeds that could

be seen growing up from the depths, but kept a sharp and con-

stant watch of the clear sand that was almost without vegetation.

There only were traces of.the dugongs to be found, and never in

the rank forest of seaweeds.

56 THE AMERICAN NATURALIST [Vor. XL

At our request Professor Aschersohn of Berlin, had the kind-

ness to examine the species of plants found in the stomachs of

the dugongs, and determined the one to be Halophila ovalis (of

the Hydrocharidaceze) and the other a species of Zostera (Zos-

tera capricorni Aschersohn). ‘The latter grows as a dense or

scattered low bed, while in Halophila the root stalk and petiole

are hidden in the sand and only the small leaflets project slightly.

These two plants do not occur on rocky bottoms. ‘The Halophila

growth is limited to a depth of about six meters below the low

tide mark; higher up, the growth becomes sparser until it entirely

disappears. The white sand, peculiarly flecked and spotted by

the Halophila leaves, is the especial feeding place of the dugong.

'The slight depths at which the dugong's food plants can grow

also explain why the animal spends part of its life in the shallow

seas and part in the off-shore waters.

Among the beds of Halophila are the so called dugong's tracks

which at once show us how the animal takes its food. The tracks

are long, curved, or wavy furrows in the white sand, with sides

parallel, about four fingers broad and from four to six cm. deep.

They are completely denuded of the Halophila. ‘Their age is

determined by the condition of their edges; fresh tracks have

raised, sharply defined edges rising from one to two: cm. above

the sea bottom. If the strong flood tide has swept over them

once, the sand becomes washed away, the edges obliterated, and

the depth less, until finally they are entirely washed away. ‘These

furrows, showing white through the dark water, indicate the

presence of the dugong. ‘They are produced by the dugong pass-

ing over the Halophila beds as it feeds, pulling up the plants

with its palatal processes, seizing them and perhaps washing

them free of sand and other extraneous matter after the manner

of certain waterfowl (ducks), and then chewing them up with its

molar teeth. The dugong trails are not made up of separate

marks which would indicate that the food is not plucked or bitten

off in tufts. Such plainly continuous trails could not be made

by the animal's lying sluggishly at the sea bottom. Also the

. peculiar lateral mark made by the tusks' in case of the male is

1 Finsch believes that the tusks serve for uprooting the sea grasses rather

than as weapons, but the fact that they are lacking in the females, argues

against this view.

No. 469] BIOLOGY OF THE DUGONG 57

explained by the method of feeding just described which neces-

sitates their active share in this process. Finsch, however, speaks

of dugong tracks that were found on bars left more or less dry

at low tide and could be readily recognized by the cropped sea

grass, the disturbed bottom, and the imprints that were left by

the animals’ bodies. ‘The first of these marks is established by

the description preceding, but we may very well doubt whether

the last is possible. Nothing of the sort was certainly observed

in Moreton Bay, Sandy Straits, Wide Bay, and the northern Coral

Sea.

There can be no doubt that the sensitive upper lip plays an

important part in the taking of food. We know from the numer-

ous careful observations made on living manatees in aquaria (we

may mention only Brown, Murie, and Noack) how extensively

these animals use the upper lip in feeding. It is unnecessary to

lay particular stress on the fact that the food plants of the man-

atee are considerably different from those of the dugong because

of their different habitats. The feeding habits of the dugong,

as described, likewise differ in a general way from those of the

manatee.

The washing of the food plants in the mouth must be very

thoroughly done. Moreover, the dugong in its progress stirs

up a quantity of sand and other inorganic particles but for all

that, matter of this sort is seldom found in its stomach contents.

It has been previously stated that the captured dugong while

being pulled ashore, voided excreta and intestinal gases with the

characteristic dugong odor. It likewise did the same while lying

hauled out on the land. The fæces were rather solid, cylindrical,

and greenish yellow to greenish black, aromatic but not foetid;

in the water they sank at once. Brandt (’69, p. 235) on the other

hand, states that the intestinal contents of the Sirenia are strongly

foetid, that the excreta float on the water, and are similar in form

to those of the cow or the horse. Chapman (’75, p. 460) records

that the fæces of a captured manatee that appeared to be suffer-

ing from constipation, were very hard, and that a constant stream

of gaseous bubbles was given out from the anus. Murie (’80,

P. 22) in case of his manatee merely mentions the droppings.

Noack (’87, p. 300) on the other hand, states positively that the

58 THE AMERICAN NATURALIST [Vor. XL

excreta of Trichechus senegalensis appear greenish brown and

rather formless, and that they are usually seen in the water only.

Brandt’s description agrees with neither the dugong nor the man-

atee. The urine of the dugong is clear as water.

Unfortunately no exact observations could be gathered as to

the temperature of the dugong. The captured specimen, when

brought out on land grew remarkably cool. The rectum showed

a temperature of 19° C. Immediately after its death the ther-

mometer was thrust into a cut made towards the base of the heart.

"The dark red blood, laden with carbon dioxide, that gushed forth

had a temperature of 17° C. One can therefore hardly express

an opinion as to the normal temperature of the dugong, espe-

cially as the temperature of the air (taken by whirling the ther-

mometer under a clouded sky) was from 12° to 18° C., and the

animal had lain motionless for 48 hours. In addition the heavy

body, weighing some 192 kilograms, pressed the easily fixed .

sternum hard against the heart, whereby the activity of the lat-

ter, the blood circulation, and consequently the body temperature

must have been very much disturbed. The marked increase in

the interval between breathings is also evidence for this. ‘The

beating of the heart could not be detected either by its palpitation

or by auscultation. This dugong impressed one as an animal

that had become cooled off, and whose temperature conditions

(irrespective of its abnormal position on the shore, and the un-

usual pressure) were so sensibly disturbed that it had lived only

a short time after being taken from the water. Moreover, obser-

vations on manatees taken and kept in captivity, show that almost

always changes in temperature are the cause of the sickness and

death of the animals (Chapman, ’75, p. 461; Murie, ’80, p. 23;

Crane, '81, p. 460).

No voice or production of a sound on the part of the dugong

could be detected beyond the blowing already mentioned, that

accompanies exhalation and inhalation and it is similar to that of

the dolphins. Finsch leaves the question open as to whether or

not there is a real voice. The earlier writers speak of a hollow

moan or snort in the case of adult animals, and of a short, sharp

ery frequently repeated on the part of the young (Brandt, '69,

p. 235). However, Brandt thought all these sounds were pro-

No. 469] BIOLOGY OF THE DUGONG | 59

duced by dying animals only, for Steller likewise stated that the

uninjured rhytinas never uttered a sound, while the wounded

ones gave a sort of hollow moan. Also in the case of the mana-

tee no trace of a voice has been observed (Murie, ’80, p. 22) though

Murie believes that this may be different under other circum-

stances. Nevertheless it is to be remembered that the Sirenia

have no vocal cords and that therefore sounds or noises may per-

haps arise through vibrations of the laryngeal cartilages and should

thus presumably take their course out through the nose.

As regards the activity of the sense organs the dugong as well

as the manatee has reached a considerable degree of develop-

ment. 'lo many sense organs we are unable to assign a very

definite function. This is true of the senses influenced by chemi-

cal stimulation, particularly the organ of taste, although as Gmelin

(92, p. 18) has shown, a taste organ is found in the manatee in

the form of a so called papilla foliata. The care shown in the

selection of food likewise points to a certain taste function. It is

still more difficult to demonstrate the function of the organ of smell

since the olfactory region is a nasal tract that is hermetically closed

when under water. And yet Chapman claims that in conformity

with the well developed bulbi olfactorii, the sense of smell must

be very keen, for it was observed that his captive manatee seemed

to become aware of food thrown in the water through its sense of

smell rather than by any other sense. Brown (778, p. 295) says

the same, referring to Chapman.

Boenninghaus (:03, p. 91) has pointed out that mammals that

seek their food in the water, can make no use of their sense of

smell in obtaining it because the nose is tightly closed in diving.

Even if this were not the case, he continues, mammals would

still be unable to smell under water since the necessary stimulus

for their olfactory nerves consists of scent particles which are

held in suspension in the air and not, as with fishes, those that

are suspended in the water. ‘The disuse of these organs in the

case of whales has led to their partial atrophy or total disappear-

ance. ‘Thus in the toothed whales the olfactory nerve is lacking,

and correlated with this is the reduction of the exethmoid bones.

In the Sirenia, however, in spite of a reduction in this bone, an

olfactory nerve and bulbus are well developed, and this, too, not-

60 THE AMERICAN NATURALIST [Vor. XL

withstanding the objections just mentioned to the possibility of

a smelling function. This possibility becomes a probability if

not a reality by the observations on the manatee given above.

From these observations it follows that in the Sirenia, at least,

there is no connection between the reduction of the exethmoids

and that of the olfactory nerve as there may be in case of the

whales. It is also clear that the olfactory nerve as a functional

structure must be capable of perceiving chemical stimuli that

utilize water as the carrying medium instead of air as with land

mammals. This assumption, of course, implies not only a par-

tial functional adaptation of the olfactory nerve but it also limits

such an adaptation to the herbivorous Sirenia alone. Finally we

must also assume that the chemical stimulus, since it cannot

reach the olfactory membrane in the usual way, must take another

course, perhaps by way of the mouth, pharynx, and choanes.

One more observation on the reflex irritability of the nasal

membrane may be added here. Before the death of the captive

dugong, Dexler endeavored to squirt water into the animal's

nose as it drew in a breath. Instantly there came so violent an

expulsion of the fluid — which had barely entered the nostril —

that it was blown into a fine spray. The reflex was astonishingly

violent and quick, and after it had taken place the nostril open-

ings were fast closed as before. Thus the breathing movement

that had been begun, was not completed. Surely so prompt a

reaction is of the greatest importance for aquatic mammals.

The action by which the nose is closed in case of the dugong is

thus two-fold: voluntary and reflex. Water pressure as an aid

is not necessary, or at least only auxiliary.

'The dugong's sight must be characterized as rather poor.

Otherwise it would be impossible to capture the animal with

so roughly constructed a net, as is actually done. Nets from 80

to 150 meters long and from 5 to 6 meters deep are so disposed

over the dugong's feeding grounds as to form a vertical wall.

If a dugong comes in contact with the net, then it is usually all

up with him; but a dolphin or a shark is never captured in so

simple a manner. To be sure, the dugongs avoid the nets more

easily on clear nights and for this reason the best time to take

them is during the nights of the new moon. The cords of the

No. 469] BIOLOGY OF THE DUGONG 61

net are colored brown also. But if one is lucky he may capture

the animals during the full moon as well, and even with new nets

of shining whiteness. A further proof of the poorly developed

vision is the fact that the captive dugong did not notice very

much the waving of a white or a black flag and that not infre-

quently no notice was taken by the dugongs of the noiseless ap-

proach of the boat so that it was possible to observe these ani-

mals at very close quarters. Semon has remarked the same thing

and the fishermen employed by Dexler asserted that they had

- repeatedly sailed right over feeding dugongs. This might be

due, however, to the fact that it does not seem particularly shy

(Semon) or that it is but little concerned for its own safety

(Finsch). Feebleness of vision has likewise been recorded in

case of the manatee (Chapman, '75, p. 454; Brown, ’78, p. 295).

Investigation of the eye in case of our captive dugong was very

diffieult and therefore inadequate. For in order to do this one

must lie directly beside the animal on the sand, and as may be

readily seen, this is, to say the least, disconcerting when one does

not know what movement the creature may make next. More-

over, the focal illumination was considerably hindered because

the bulbi were deep set and constantly held pointing slantwise

forward and downward, and the slit between the eye lids was

narrow. Furthermore there flowed from the conjunctival sac

such a quantity of tough, stringy secretion that the eye opening

was constantly obstructed as with a thick plug.

'l'his had first to be removed and the short intervals before its

re-formation were utilized in a rapid study of the front portion

of the eye. It was impracticable to expose the bulbus by open-

ing the eye lids with one's fingers for these were closed tightly

at the slightest touch. If they were forcibly pressed apart the

nictitating membrane was then pushed up and the bulbus re-

tracted in such a way that it disappeared under the membrane

and the periorbital masses of fat that were forced forward. After

five or ten minutes there appeared at the bottom of the fatty

funnel thus formed a bit of the cornea like a small black spot

which became no clearer in spite of long waiting. When the

finger was removed the eye returned to its proper place, but for

hours after it remained more deeply in the socket than it had

62 THE AMERICAN NATURALIST [Vor. XL

been before the investigation. This retraction movement took

place independently of the position of the other bulbus.

By combining a number of partial observations, only the fol-

lowing particulars could be made out: a very strongly curved

cornea, a considerable mobility of the blackish brown iris which

reacted promptly to light, an indistinct radial striation, and a

circular pupil.

The use of the ophthalmoscope seemed at first to be attended

with no results, for nothing but a deep black was visible. Then

at a chance motion of the dugong’s éye the small, round rose-

colored papilla or the disc of the optic nerve came in sight. There-

upon further exploration of the retina was made though without

additional results. The entire area of all four quadrants con-

sisted of a deep black continuous tapetum nigrum in which no

details could be made out, as is likewise true to some extent in

case of the ventral portion of the fundus of the horse. In order

to perceive clearly the few extremely delicate capillaries that

radiated to the tapetum from the upper rim of the disc required

an increase of the observer’s myopia from 23 to 5 dioptria from

which may be deduced the degree of short-sightedness .of the

animal when out of water. The refraction of both eyes was the

same.

It is noteworthy that the dugong also exhibited a certain dis-

like for bright light. At least one may so conclude from the

eagerness with which it sought the shadow cast by the hull of

the cutter.

In the manatee the pupil is round in life, but is transversely

oval when the animal is dead (Murie, ’80, p. 24). The dugong’s

pupil did not change shape after death. As in the manatee the

nictitating membrane is well developed and freely movable. The

eyelids are contractile and can be brought together until there is

only a small slit, 12 mm. long, that remains not quite closed.

The complete isolation of the bulbus from the exterior is effected

by the nictitating membrane and the periorbital fat. The lids

when closed are deeply wrinkled in a radial fashion, on account

of the very strong orbicular contraction. This fact disposes of

Piitter’s (:03, p. 369) assumption based on the study of an em-

bryo dugong whose eye slits were 5 mm. long and 3 mm. broad,

No. 469] BIOLOGY OF THE DUGONG 63

that the eye lids as in case of the whales cannot be opened nor

approximated. ‘The copious secretion of the conjunctival sac

has already been mentioned. In our captive the string of slime

was of the consistency of the white of an egg, was as thick as

one’s finger, and flowed over the entire eye and down to the

ground. ‘That this secretion might be due to the irritation caused

by the atmospheric air or the unaccustomed light immediately

suggested itself, but in all the animals taken the secretion was

similar without any difference in regard to mass, thickness, con-

sistency, nor transparency and thus possessed properties not

present in a catarrhal flow. The corneal reflex was easy to demon-

strate and the eye lids were always held open.

The eyes of the dugongs that were dead when taken, were

always injured even if they had hung in the nets only six or eight

hours. In such cases there were uneven scratches with finely

serrated edges, spreading superficially or even onto the mem-

brana descemeti. They were always interior to the poles of the

cornea, which lay free in death. The lens usually showed star-

shaped to diffuse whitish cloudy spots that generally became

more pronounced the longer the body was allowed to remain in

the water. These spots were doubtless phenomena incident to

death. The secretion of so great a quantity of slimy viscous

matter from the conjunctiva is a protective adaptation to keep

the surface of the eye from injuries from the sea water or its plank-

ton fauna. If the slimy covering fails then the bulb of the eye

is without protection. In this way are caused the scratches above

mentioned, of whose traumatic nature there can be no doubt.

In some specimens this even results in the eye lids becoming so

abraded that they bleed freely.

The presence of a slimy protective coat for the eye has also

been demonstrated for the whales, only in them it is not watery

and mucous as in the dugong, but oily for otherwise it would be

too easily washed away by the sea water (Piitter, :03, p. 370).

Thus in the Cetacea a change of function has taken place in the

glands of the eye as an adaptation to the conditions of aquatic

life, and their products are likewise changed.

The copious secretion of mucus from the dugong’s eye has

long been known to many of the islanders of the Malay archi-

64 THE AMERICAN NATURALIST [Vor. XL

pelago. All sorts of fantastic tales are associated with the so

called dugongs’ tears, in regard to their use as a powerful charm.

Brandt (’69, p. 274) speaks only of the young dugong’s shed-

ding tears and that these were carefully gathered because they

aroused in the possessor an affection as strong as that of the female

dugong for its young. This belief was taken advantage of by

the German and French perfume makers in order to assure a

better market in Java for their perfume imported under the name

of “dugongs’ tears," “ajer mata doejoeng” (Dexler, :05, p. 200).

In contrast to the senses hitherto mentioned, that of hearing

appears to be very well developed in the dugong. Both in the

water and on the land the animal seemed to be much more affected

by sound impressions than by those of sight. ‘The dugong lying

on the beach winced considerably at a sharp squeaking sound

made by drawing in air between the puckered lips, as do also the

guinea pig and the mouse. Only after numerous and quickly

repeated stimuli of this sort did it remain motionless. Whether

its ear was acoustically over sensitive with the absence of water

pressure could not be determined. Nevertheless some sort of a

stimulating influence is within the range of possibility since the

meatus acusticus externus de norma transmits the pressure of

the water to the ear drum. Also in the great size of the ear bones

is seen an adaptation for hearing under water and not in the air,

just as in whales (Boenninghaus, :04, p. 282). Evidence for

keenness of hearing in the dugong is also found in Finsch's state-

ment to the effect that in setting out the hunting-scaffolds for

capturing the dugong, one must work with great care since the

slightest rattling of these is said to be enough to frighten the ani-

mals away. Also in harpooning them one must proceed with

absolute silence (Fairholme). Dexler’s fishermen gave the floats

of their nets a wedge-shaped form in order, as they claimed, to

obviate the slight noise produced by the waves in striking floats

of any other shape, and so frightening the animals away. But

as a matter of fact the dugongs were rather frequently captured

when the floats splashed loudly.

Besides the sense of hearing, we must also accord a fairly good

development to that of cutaneous sensibility. The large upper

lip appears to be very richly provided with nerves of feeling and

No. 469] BIOLOGY OF THE DUGONG 65

as is evident from its anatomical construction, it is especially

adapted for a manifold touch function, a fact that is of the greatest

importance in the procuring of food. Apparently it serves in

some degree to offset the seemingly poor eyesight, so that the

animal in its wanderings over the beds of seaweed may be ac-

quainted of the presence of blocks of coral, stones, and the like.

The finely developed sense of touch in this organ is also shown

by the fact that it was never found to be injured, in contrast to

the skin of the rest of the body.

The presence of numerous scars and scratches on the skin of

the back and sides of the body is characteristic of the dugong.

As to their origin one can only guess. A very small portion of

them may be set down as due to the wounds from the tusks of

the males. Even in the oldest of 25 specimens examined, these

tusks projected only 32 mm., and on their median sides they were

almost entirely covered by the palatal processes. ‘They are there-

fore very poorly adapted for making wounds. Possibly the ani-

mals wounded themselves in their endeavors to scrape off clinging

parasites. The fishermen give a different explanation: they

maintain that they have often seen the dugongs while at play,

wound their backs on stones and corals as they rolled or swam

about on the bottom. They thought the dugongs did this par-

ticularly over beds of Pinna shells, but it was impossible to deter-

mine this point.

There is little to be said in favor of the much discussed intel-

ligence of the dugong. We have thus far seen no convincing

evidence for according a particularly high degree of acuteness

to a single one of the animal’s senses. The senses of hearing

and touch may be deemed the most highly developed; then, in a

descending series, sight, taste, and smell. But even the keen-

ness of hearing accorded the dugong cannot be compared with

that of a really very keen-eared animal; otherwise the fact would

be inexplicable that it is possible, though rarely to be sure, at

times to sail up to feeding dugongs. When Dexler saw the herd

of dugongs, previously mentioned at Moreton Bay, his men were

rowing with splashing oars and without particular precaution.

It must also be recalled that the often emphasized sound stimulus

in water may frequently be communicated by the sensitive skin

66 THE AMERICAN NATURALIST [Vor. XL

and mucous membranes of the head as well. The other senses,

as before mentioned, are much less well developed. Consider-

ing the manifestly slight capabilities of the peripheral sense organs,

it can hardly be concluded that the central nervous system has

reached a high state of development. In fact, the brain of the

dugong is not only relatively small — 445 to ¢}o of the weight

of the body — but as we shall show in a later paper, it is so lowly

organized that only a comparatively slight degree of intelligence

may be presumed in this animal. A further proof of the stupidity

of the Sirenia is found particularly in their behavior towards

enemies, in their defencelessness, and in the ease with which they

may be killed and exterminated.

Another question which we will here treat at further length

is that of the use of the flippers. While on the one hand it is

assumed (Freund, :04, p. 346, and elsewhere) that the flippers

of the Sirenia are used as paddles and balancing organs, on the

other hand it is supposed (Abel, :04, p. 186, etc.) by way of ex-

plaining certain anatomical changes, that their function is that

of supports. In the dugong, particularly in case of the specimen

that lay on the shore, one could clearly see that movement from

place to place in the water was accomplished solely by means of

the caudal fin. The pectoral limbs were held motionless at the

sides, and directed backwards. If one endeavored to roll the

dugong over on its side, it began to strike out with its tail but

allowed its pectoral limbs to remain where they were. Active

movements of the flippers for the purpose of locomotion on dry

land were not observed.

'There has been very little recorded as to the movements of

the dugong on dry land in general, where a use of the append-

ages in locomotion is to be presumed. Klunzinger makes only

the indirect statement that in the northern part of the Red Sea

they are frequent in winter especially in December and January,

and that otherwise they seldom go to the land. Finsch (:01, p.

10) speaks of an account by Leguat who was led to Rodriquez,

in 1691, mainly on account of a dugong that was seen lying on

the shore. Still, in Finsch’s opinion this was a stranded animal

since the dugong does not voluntarily go onto the land, and more-

over has nothing to seek there. If a dugong be captured and

No. 469] BIOLOGY OF THE DUGONG 67

thus foreibly brought to land, it may live 24 hours he was told

by old Kabury on Palau. This observation is corroborated by

that on our dugong which passed an even longer time — 48 hours

— on land. It appears therefore that the dugong has not been

actually observed to come out onto the land of its own accord,

and in our opinion such a procedure is out of the question since

the pectoral limbs are insufficient to enable the animal to do this.

In no wise can it be established, as Brehm would have it, that

“one can at least assume that those dugongs that have been seen

lying on the shore were left by the ebb tide and were too sluggish

to push their heavy bodies into the water again, preferring rather

to wait quietly the next flood tide." They are simply incapable

of using their anterior limbs, even as supports, on dry land. ‘The

possibility still remains that they support themselves on their

flippers while gathering their food in the water. But against

this supposition, in the first place, are their observed manner of

feeding and the so called dugongs’ tracks. In the second place,

the difference in specific gravity between the animal’s body and

the supporting medium, cannot, in view of the considerable mobil-

ity of the dugong, be such as to entail any great burden on the

limbs. ‘Thirdly, the slender form of the appendages, their rela-

tively small size, and finally the uninjured epidermis on the parts

in question, furnish evidence against their use as supports in the

water. Also in the case of the manatee, here adduced for com-

parison, the use of the flippers as organs of support is denied rather

than maintained. Moreover, Brandt cites three authors who

conclude from the manner of capturing the American manatee,

that it is incapable of getting back to the water (by the aid of the

limbs) if left up on the dry land. Garrod (’77, p. 139) says very

decidedly that his manatee seemed wholly unable to move either

forward or backward on the land. It made- use of the limbs in

sidewise movements only, at the same time twisting the body and

tail. Chapman (’75, p. 461) and Murie ('80, p. 26) observed

that their manatees swam quietly about at the bottom of the aqua-

rium with the body sharply bent and the head and tail pointed

downwards. Neither author says a word about their supporting

themselves on their flippers, and Murie figures the animal in

the posture described, with the limbs hanging down. He men-

68 THE. AMERICAN NATURALIST [Von XL

tions their aid only in the taking of food. . Brown (778, p. 296)

brings up still another argument against the possibility of a man-

atee being able to leave the water by aid of its flippers, namely

the weakness of these organs, and his investigations into this

matter also resulted negatively. Crane ('81, p. 457) makes a

similar statement, basing his opinion on the generally clumsy

movements of the animal when on dry land as well as on certain

other considerations. Opposed to these observations are only

the statements of Cunningham ('70) and Noack ('87, p. 299).

‘The former saw a manatee support itself above the water by its

flippers in order to crop the grass at the edge of the shore. ‘This

was done in such a way that one limb rested upon the shore. ‘The

latter author goes still further, for he states that the manatee is

able to come out and move about on the land. “The animal

(M. senegalensis) can actually move from place to place, though

in a hobbling and unsteady manner. In so doing it supports

itself on its wrists [!] and the outer edge of the forwardly directed

hands, moving them alternately, and thus it progresses forward,

though slowly, wriggling its body as it goes." But one may also

suppose that the wrigglings of the body were the primary and

locomotor movements, while the motions of the flippers might

have prevented the body from falling over. In any case the

position of these limbs as described is very remarkable! Noack

relates that his manatee while in the water used its flippers to

remove from its mouth pieces of bread that had proved too large.

But as for a supporting function of these organs while in the water,

Noack likewise knew of no evidence.

To sum up, it must be said, then, that scientific observation

on the sea cows (for in case of the rhytina, also, Steller mentions

that they are unable to move about on land) has hitherto pro-

duced but slight evidence that would permit us to assume so con-

siderable a use of the flippers for body-supports as would explain

the development of many anatomical details. ^ Nevertheless,

theoretically one may suppose it has only chanced that the use

of the limbs as supports has been so seldom seen. But on theo-

retical grounds also, considerable objection may be raised against

the evidence brought forward by Abel (:04, p. 166) as has already

been done in the course of this discussion. We should remember

CE QOIS

ee SE aaa a

No. 469] BIOLOGY OF THE DUGONG 69

that the Sirenia have arisen from air-breathing land forms of

Mammalia; further we should not forget that their terrestrial

type, with its adaptations of the body to pressure and weight,

is greatly modified by adaptations to an aquatic life. Thus as we

trace the evolution of the Sirenia, their mechanical adaptations

to terrestrial life will be less and less noticed while those for aquatic

existence will increasingly force themselves upon our attention.

In like manner the anatomical changes brought about by these

adaptations show the same progression. Such convergent ana-

tomical changes in animals of the same biological environment

are due to the influence of identical causes. In the case of these

water mammals where proof of such changes is impossible to-day,

we need not always assume different causes; here the same causes

were acting on different objects (e. g., Cetacea and Sirenia) and

therefore it is conceivable that the same causes may bring about

different results.

The dugong is the host of great numbers of parasites, both

external and internal. On its back, as with whales, numerous

barnacles establish themselves; a few Balanus but mostly Chel-

onobia. Internally, at the opening of the inner nares, on the

dorsal surface of the velum .palatinum, but particularly in the

Eustachian tubes of both sides, were found numerous leaf-shaped

trematodes from 3 to 5 mm. long clinging to the membrane in

a mass of an hour-glass shape. These must have been identical

with the Opisthotrema cochleare described in 1884 by Fischer.

He had received them from Semper (of Wiirzburg) who collected

them in the Philippines from the tympanic cavity of the dugong.

Leuckart also, in 1875, described a trematode from the Eusta-

chian tube of the dugong under the name of Monostomum dujonis.

Von Linstow (’78) considers both forms as probably identical.

The favorite habitats of these trematodes give, we believe, an indi-

cation of the path by which the infection has spread in case of

the dugong, namely, from the nose, to pharynx, Eustachian tubes,

and tympanic cavity. To be sure, Boenninghaus (:04, p. 259) has

controverted the idea that in case of the parasites of the whale’s

ear the path of infection has been through the pharynx and the

Eustachian tubes. He himself mentions a nematode, Pseudalius

minor Kuhn, from the ear cavity of Phocena. Moreover, von

70 THE AMERICAN NATURALIST [Vor. XL

Linstow records Strongylus arcticus Cobb from the ear of the

beluga, and Pseudalius alatus from the Eustachian tube and the

pharynx.

In the alimentary tract of the dugong, trematodes occur in

the gut and the cecum. In the small intestine some very large

worm masses were observed, whose composition could not be fully

determined. In addition, a species of Ascaris has long been

known from the digestive tract and numerous specimens of this

were also found in the glands of the stomach. It is Ascaris

halicoris Owen, also wrongly called Ascaris dugonis Brandt.

Whether the Ascarid seen by Steller in the rhytina is identical

with that found in the dugong cannot now be determined. Two

endoparasites are also described from the manatee: a nematode,

Heterocheilus tunicatus Diesing, and a trematode, Amphistomum

jabaceum Diesing (von Linstow, '78, ’89). Chapman (775, p.

456) found the large intestine of his American manatee filled

with the latter.

VETERINARY INSTITUTE OF THE

GERMAN UNIVERSITY OF PRAGUE

USTRIA

LITERATURE

ABEL, O.

04. Die Sirenen der mediterranen Tertiarbildungen (Esterreichs.

Abh. Geol. R. Anst. Wien, vol. 19, pt. 2

BoENNINGHAUS, G.

Der Rachen von Phocena communis Less. Eine biolog. Studie.

Zoöl. Jahrb., Abth. f. Anat., vol. 16, pp. 1-98, 1 pl.

BoENNINGHAUS, G.

- Das Ohr der Zahnwale, zugleich ein Beitrag zur Theorie der

Schalleitung. Zoöl. Jahrb., Abth. f. Anat., vol. 19, pp. 189-360,

2 pls

BnaNpr, J. F.

'46-'69. Symbole Sirenologiee. Mém. Acad. Imp. St. Pétersbourg,

ser. 6, vol. 5, p. 1-160; ser, 7, vol. 12, pp. 1-384. -

ED BET AAE ALL 7 A ee

No. 469] BIOLOGY OF THE DUGONG 71

BREHM, 8.

'91. Halen 3 Aufl, bearb. von Pechuel-Loesche: Säugetiere.

"78. The Sirenia. Amer. Naturalist, vol. 12, pp. 291-298.

CHAPMAN, H. C.

"n drin on the Structure of the Manatee. Proc. Acad. Nat.

i. Phila., 1875, pp. 452-462, 1 pl.

CRANE, Ü

'81. Notes on the Habitsof the Manatee (M. australis) in Captivity in

the Brighton Aquarium. Proc. Zool. ¥ Soc. London, 1881, pp.

456-460.

CUNNINGHAM, R. C

’70. Letter from....concerning a Specimen of the Manatee (M.

americanus) kept alive in Captivity. Proc. Zool. Soc. London,

1870, p. 798.

Dexter, H.

02. Bericht über eine Reise nach Australien, zum Zwecke der Erwer-

. bung anatomischen und entwicklugsgeschichtlichen Materiales

vom Dugong. Deutsche Arbeit., vol. 1, pt. 7, pp-

DExtLER, H.

:05. e Leipzig, 200 pp.

Famnorm

G the Australian Dugong (Halicore australis). Proc. Zool. Soc.

London, vol. 24, pp. 352-533. :

Finscu, O.

:01. Der Dujong. Zoologisch-ethnographische Skizze einer unter-

gehenden Sirene. Samml. gem. verst. Vortr., Holtzend, pt. 359.

Hamburg.

FREUND, L. -

:04. Die Osteologie der Halicoreflosse. Zeitschr. f. wissensch. Zoöl.,

vol. 77, pp. 363-397, 2 pls.

Garrop, A. H.

Notes on the Manatus, recently living in the Society’s Garden.

Trans. Zool. Soc. London, vol. 10, pp. 137-145, 3 pls.

GMELIN, D.

'92. Zur Morphologie der Sager vallata und foliata. Arch. mikr.

Anat., vol. 10, pp. 1-38, 1 pl.

KruNziNGER, B.

"TB. Die Wirbeltierfaunaim und am Rothen Meere. Zeitschr. Gesellsch.

Erdk. Berlin, vol. 13, pp. 61-96.

Krauss, F.

"T0. Beiträge zur Osteologie von Halicore. Arch. Anat. Phys., 1870,

pp. 525-614.

LANGKAVEL, R.

'906. Der Dugong. Zoöl. Garten, 1896, p. 337.

72 THE AMERICAN NATURALIST [Vor. XL

von Linstow, O.

"78. Cpa der Helminthologie. Ein Verzeichnis der bekann-

ten Helminthen, ete. Hanover, 382 p

voN Linstow, O.

'89. Compendium der Helminthologie. Nachtrag. Die Litteratur

der Jahre 1878-89. Hanover, 151 pp.

Munig, J.

"4. On the Form and Structure of the Manatee. Trans. Zool. Soc.

London, vol. 8, pp. 127-202, 10 pls.

MURIE, .

'80. Further Observations on the Manatee. Trans. Zool. Soc. Lon-

don, vol. 11, pp. 19-48, 5 pls.

Noack, TH.

'87. Lebende Manati. Zoöl. Garten, 1887, pp. 293-302.

PUTTER, A.

:03. Die Augen der Wassersüugetiere. Zoöl. Jahrb., Abth. f. Anat.,

vol. 17, pp. 99-402, 3 pls.

Rupeni, E.

Beschreibung des im Rothen Meere vorkommenden Dugong

(Halicore). Maus. Senckenberg., vol. 1, pp. 95-114, 1 pl.

TunNER, W. 2

’94. The Foetus of Halicore dugong and of Manatus senegalensis.

Journ. Anat. and Phys., vol. 28, pp. 315-334.

WALDEYER, W.

'86. Beiträge zur normalen und vergleichenden Anatomie des Pharynx

mit besonderer Beziehung auf den Schlingweg. Sitzb. preuss.

Akad. Wissensch. Berlin, vol. 1, pp. 233-250.

CORRESPONDENCE

Congress of Oceanographers

Editor of the American Naturalist.

Sir:— I enclose copies of correspondence in regard to a Congress

on Oceanography which is to be held in connection with the Colonial

Exposition at Marseilles, France, in 1906, and in compliance with the

French Ambassador’s request, invite your attention to the desire of

the organizers to secure the coöperation at the Congress of the asso-

ciations and individuals named in the accompanying list, the Amer-

ican Naturalist being among them.

a I am, sir,

Your obedient servant,

ROBERT BACON

Acting Secretary

DEPARTMENT OF STATE, WASHINGTON

October 11, 1905

Translation of Letters from French Embassy

Mr. Secretary of State.

The Minister for Foreign Affairs has sent me a letter in which

Mr. Charles Rouse, Commissioner General of the Colonial Exposi-

tion to be held at Marseilles in 1906, expresses the wish to have the

attention of the Government of the United States invited to the sec-

tion of Oceanography of that Exposition.

In order to comply with this request, which is particularly com-

mended by the Minister of Commerce and Industries, the French

Ambassador desires to request the Federal Government kindly to

invite those persons in America, who make a study of oceanography,

to take the result of their studies to the Marseilles Exposition, com-

municating to the particular ninth section of said Exposition, the

results of their research and to participate in the Congress on Oceanog-

raphy which will be organized under the auspices of the section in

question.

I shall thank Your Excellency for kindly informing me in order

74 THE AMERICAN NATURALIST [Vor. XL

that I may notify my Government, of the replies which the Depart-

ment of State shall receive to this communication.

Accept, Mr. Secretary of State, assurances of highest esteem.

Des PORTES

EMBASSY OF THE FRENCH REPUBLIC

IN THE UNITED STATES. WASHINGTON

October 2, 1905

Mr. Secretary of State.

Inder date of September 11 last, this Embassy had the honor to

invite attention of the Department of State to the interest felt by

the Republic in the Colonial Exposition at Marseilles, and partic-

ularly the Section of Oceanography and Sea-fishing, which is a part

thereof. Referring to that communication as well as to the kind

reply made by the Department of State, I take the liberty of trans-

mitting herewith to Your Excellency a list of the associations and

individuals who, in the opinion of organizers of the projected reun-

ion, would be especially apt to contribute to its success.

I should be very grateful to Your Excellency if you would request

them to signify their adhesion to this important international mani-

festation which promises to be of great scientific as well as practical

interest.

Accept, Mr. Secretary of State, assurances of my high esteem.

: JUSSERAND

EMBASSY OF THE FRENCH REPUBLIC

IN THE UNITED STATES

NEWPORT

September 11, 1905

(No. 468 was issued Dec. 14, 1905)

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VOL. XL, NO. 470 FEBRUARY, 1906

THE

AMERICAN

NATURALISI

A MONTHLY JOURNAL

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IN THEIR WIDEST SENSE

CONTENTS

Page

I. The Unity of the Gnathostome Type ped e cee DR. Eie RIES T

II. Old Age in Brachiopoda — Prettwinarg Study | . . DR. H. W. SHIMER 95

III. The Habits of Necturus PONE . PROFESSOR A. C. EYCLESHYMER 123

IV. Notes and Literature: Zoó/ogy, Kellogg's American Insects, Kingsley’s Ele- 187

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of Iceland, Holder’s Half Hours with the Lower Animals; Notes, A

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_ WILLIAM M. DAVIS, M.E., Harvard Uawr

THE

AMERICAN NATURALIST

Vor. XL February, 1906 No. 470

THE UNITY OF THE GNATHOSTOME TYPE

HOWARD AYERS

SINCE zoölogists have recognized the simple nature of the

Cyclostome fishes there have been many contributions to our

knowledge of their structure and many discussions as to their

nature and their true zoölogical position.

The increase in our knowledge of the anatomy of amphioxus

and the clearing up of its development by the investigations of

Kowalevsky, Hatschek, and Willey, have increased the amount of

interest in these discussions and have added to the subject an en-

tirely new phase in that the amphioxus, instead of being longer

considered a zoölogical curiosity, a degenerated or aberrant form,

has become the center of an intense and searching discussion of

the origin and relationships of the Vertebrata; and amphioxus

has thus come into its own by being recognized as an ancestral

form in the genealogy of the vertebrate stock and the oldest living

relative and representative of this group of animals. -

We can now see clearly enough that the Marsipobranchia and

the Acrania both stand in the relation of ancestors to the verte-

brates above them, and there is no longer any doubt, while recog-

nizing to the full the many unsolved problems in connection with

its structure and development, that amphioxus belongs to the

group of forms, the Prospondylia, predecessors of the Archicrania,

from which the Cyclostomes are directly descended. It must

76 THE AMERICAN NATURALIST [Vor. XL

be admitted that the gap between amphioxus and Bdellostoma

is very great, both as regards time and the amount of the trans-

formation of structure which it has undergone, and that in many

things we cannot yet satisfactorily explain the manner in which

this transformation has come about.

On the other hand, we may with certainty say nearly as much

about the gap between the Cyclostomes and the other Gnatho-

stomes, ‘but the absence-of complete knowledge has never been

permitted to blind unprejudiced minds to the just estimate of

the known facts in any zoölogical problem.

Recent advances in our knowledge of the Marsipobranchs

render Haeckel’s estimate of the amount of difference between

the Cyclostomes and vertebrates above them quite untenable.

He says (Syst. Phylog., vol. 3): “Eine tiefe morphologische

Kluft und ein entsprechend langer historischer Zwischenraum

trennt beide Classen der Agnathonen nicht bloss von den echten

Fischen, sondern auch von allen übrigen Vertebraten die wir in

der Hauptgruppe der Amphirhinen oder Gnathostomen zusam-

menfassen."

There is no reason why we should, at the present time, follow

partisans of any genealogical theory of the origin of the verte-

brates in ignoring the many anatomical and embryological facts

which we now possess and which clearly enough establish the

genetic relations of these forms.

Some writers are too prone to assume the existence of large

groups of extinct forms intermediate between the groups of exist-

ing vertebrates and between these and those forms from which

the vertebrates have descended — which have disappeared with-

out leaving any trace of their structure in recent forms.

There is neither anatomical nor embryological ground for the

removal of amphioxus from the vertebrate class, and we may

express our view of the relation of existing forms thus:—

VERTEBRATA

Amphioxus — Leptocardia — Acrania

All others — Pachycardia — Craniata

and by the following table:—

GENEALOGICAL TREE OF THE ICHTHYOPSIDA

Amphibia

Teleostei

. Ganoidei

Petromyzon : Dipneusta

Myxinoidea ^ * Selachia

Gastrobrancha,

( Myxine )

Bdellostoma

Ammoccetes

Protomyzontes

Paleospondylus Protoichthyopsida

| |

Gnathostomata

Leptocardia

Branchiostoma

Paramphioxus )

Asymmetron

chieraniata

Agnathous Pachycardia

(Type form of the Craniat

Prospondylia

(Type form of Acraniate Vertebrates)

Tunicata

Thalidix

Ascidia

Copelata

Protochordata

(Type form of the Chordata)

78 THE AMERICAN NATURALIST [Vor. XL

Before taking up the question of the unity of the Gnathostome

type, a brief consideration of some of the general features of the

vertebrates will clear the way for a better understanding of the

arguments and facts which bear on the solution of the problem.

First of all we may well consider amphioxus as a typical ancestral

vertebrate.

The Vertebrata, as we find them to-day, form a morphological

unit in much the same way that the birds form a closed group —

and it is only through paleontology that the shading off of the

group into lower forms is to be found or proven. ‘That the verte-

brates have arisen from a common source is a statement which

cannot to-day be questioned, for the present state of our knowl-

edge of their anatomy, ontogeny, and physiology is a practical

demonstration of the problem. Each increase in our knowledge

only makes the demonstration stronger. All three fields of inves-

tigation — comparative anatomy, comparative embryology, and

paleontology — unite in one affirmation of this fact. All three show

that there has been an orderly progression (to use only living

forms as examples) from amphioxus to man. No one can read

Hasse’s Das natürliche System der Elasmobranchier, to mention

only one of many similar investigations, without having the fact

of the historical succession of these early vertebrates indelibly

impressed upon his mind. The genetic relationships of this

procession of Selachians from the earliest geologic ages, when

the fossiliferous records of the vertebrate stock were begun, is

proven by the comparative morphologic study of the skeletons

of extinct and recent forms and this proof is strengthened by the

as yet only partial, embryonic record which has been worked out

by many investigators. The course of development is marked

by the retention in all living forms of all the divergent branches

of vertebrates, from amphioxus up to the mammals, of the same

fundamental arrangement of organs and systems of organs, and

by the same general cellular structure. ‘The variations in arrange-

ments of the organs and the differences in the histological details

of the tissues are not greater than the variations of the external

form or of the shape of the internal organs. ‘These are large facts

of fundamental value, and have a greater morphologic worth

than the many minor variations can possibly have, even when

No. 470] UNITY OF GNATHOSTOME TYPE 79

taken together. They prove the essential unity and genetic

relationship of all the Vertebrata.

Semper’s view that amphioxus is not a true vertebrate has long

since been effectively disproved, and the most forceful part of

the proof that amphioxus does belong to the ancestral stock of

vertebrates is contained in its simple palingenetic development,

at least so far as the earlier stages are concerned.

The method of laying down the gills up to the time that the

secondary gills are established, is in every way comparable with

the processes of gill formation in Bdellostoma. The transforma-

tion of the brain up to the apex of its development is similar to

the development of the vertebrate brain, the only difference being

that it stops its growth in a very primitive stage of the Craniate

brain. The differentiation of the tissues is in every respect the

same as that occurring in other vertebrates, except that the proc-

ess of tissue formation does not go as far, while some tissue sys-

tems, which appear in upper vertebrates, are never developed in

amphioxus. For example, the masses of connective tissues com-

mon to other vertebrates, in the form of true cartilage and bone,

are not even hinted at. The statement that its tissues are epithelial

is most erroneous. Ä

The lack of formation of such structures as jaws, chambered

heart, lacunar hepatic gland, cartilaginous skull, etc., is certainly

to be put down as a palingenetic characteristic.

When we seek the type form of the vertebrate stock we are

forced to look to the invertebrates as the source of origin. Almost

all the groups of the Metazoa have been searched for the ancestral

type, and in nearly every case a type-form has been discovered

which shows the means of descent sufficiently satisfactory to the

individual zoologist to warrant a long and careful discussion of the

manner in which the morphologie and physiologic changes have

come about that have ‘resulted in producing the vertebrates as

we find them to-day.

Three types of structure have, however, been used more fre-

quently than the others. They are, respectively, nemertean,

annelid, and arthropod. All three of these types possess a suf-

ficient number of characteristics in common with the vertebrate

type to warrant many parallels being drawn between each of them

and the vertebrates.

80 THE AMERICAN NATURALIST [Vor. XL :

The great difficulty in thé way of accepting any of the well de-

veloped jointed invertebrates as the ancestral vertebrate type lies

in the necessity of a revolution of the body through an angle of

180 degrees, whereby the dorsal surface of the invertebrate be-

comes the ventral surface of the vertebrate; and also in the con-

comitant necessity of the formation of a new mouth and the total

disappearance of any trace of the old mouth. While there is, at

the present time, abundant evidence to show that the functional

mouth of the vertebrate of to-day is a neomorph, and that the origi-

nal mouth was situated at a point anterior and dorsal to the pres-

ent location, it does not follow and the evidence does not tend to

show, that the old mouth corresponds in any way to the mouth,

e. g., of the arthropod.

This translocation of the mouth from the invertebrate ventral

to the vertebrate ventral surface must have been connected with

the reduction of the circumcesophageal nerve ring, and with the

total disappearance of that section of the stomodaeum which con-

nects the mesenteron with the mouth by preforating the nervous

system through the territory of the circumcesophageal nerve ring.

The fact that the stomodeum no longer perforates the nerve

ring is a fact which must be satisfactorily explained by in some

way discovering the stages through which the transformation has

passed from the invertebrate to the vertebrate condition, or the

genealogy of the vertebrate stock with the arthropod as the an-

cestral form cannot be satisfactorily explained.

There is great doubt that the vertebrates are derived from a

highly organized annulate invertebrate. ‘They are more probably

a distinct branch split off from the unsegmented worms, and de-

veloped independently. Many are the theories which have been

offered to harmonize the annulate and the arthropod conditions

with the vertebrate, but none of them have accounted for a suffi-

cient number of facts to warrant their general acceptance, and, as

above stated, the main difficulty has consisted in the inability to

picture the revolution of the invertebrate body in such a way as

to make it physiologically possible in living forms.

It matters not what position we take with reference to the origin

of the vertebrate stock, when we arrive at the stage of development

represented by amphioxus we are compelled to admit, in the light

No. 470] UNITY OF GNATHOSTOME TYPE 81

of our recent knowledge, that amphioxus is a true vertebrate, lack-

ing it may be the first trace of the craniate skeleton, and lacking

many of the other features which are characteristic of most of

the existing vertebrates, but is nevertheless, the only existing form

which serves as a ‘connecting link between the simple ancestral

type of structure and the more complex anatomical and poe

ological conditions of the higher vertebrate.

Some zoólogists have recently re-uttered Semper's opinion, that

amphioxus is not a true vertebrate, but such restatement of Sem-

per's opinion is justly to be compared to the restatement of the

opinions of the older zoólogists, who at various times held amphi-

oxus to be à worm, a mollusc, and a tunicate. Instead of making

assertions as to what amphioxus is or is not, the only scientific

method of solving the problem of its actual position in the animal

series is by a careful study of its structure and a comparison of

this with the structure of the lower vertebrates. Such comparison

proves beyond the shadow of a doubt the relation of the amphioxus

to the lowest fishes.

A review of some of the salient features of amphioxus’ anatomy

will not be out of place at this point. As regards the form of the

body, all zoólogists recognize the fact that the shape of the verte-

brate body is a result of the direct response of the organism to its

environment, particularly the necessity of locomotion. The lancet

shape of amphioxus is due to its burrowing habit. The lack of

paired appendages is due to the fact that amphioxus represents

- the stage of the development of vertebrate structure when such

appendages had not yet been developed. The median fin folds

are well developed, both in the head and in the caudal region, and

serve the same function in essentially the same way that they do

in other vertebrates. There is no trace of a quasi lateral fin fold,

nor of the buds of lateral appendages in the amphioxus, but neither

of these are found in the Cyclostome fishes, which are much more

highly organized than amphioxus. -

The lack of the development of paired appendages in amphi-

oxus and the Cyclostomes is not a mark of degradation, or degen-

eration, as some zoölögists would put it, because the whole course

of their development and the facts of their morphology prove con-

clusively that these structures were not called forth by the response

82 THE AMERICAN NATURALIST [Vor. XL

of these animals to the stimuli of their environment in the direction

of pedal locomotion on the sea bottom. It is highly probable

that these appendages arose as ventrally projecting bar-like struc-

tures, to enable the bottom-living forms (since all were bottom

dwellers to begin with) to move more readily from place to place

on the surface of the sea floor while remaining in contact with the

sea floor, thus avoiding the necessity of the more difficult feat of

balancing themselves in the lighter ambient fluid above the earth

floor, in the effort to effect a change of place.

Paired appendages then did not arise as fins for the purpose of

balancing the animal in the water, but the paired fins of fishes have

been developed by the transformation of the primitive paired or-

gans of locomotion, of which the paired appendages of the Amphi-

bia and their descendants are the direct and, in their simplest

forms, the least modified derivatives. '

When one studies the life habits of amphioxus and Bdellostoma

in their natural element and, at the same time, the history of their

development, he no longer entertains the idea that these animals

have lost paired appendages once possessed by their ancestors,

but will, and can only, say that they are the ancestral forms of

animals possessing paired appendages, and that in the case of

amphioxus and of Bdellostoma we have two stages in the response

of the vertebrate stock to the stimulation of the environment

looking toward the formation of locomotor appendages. !

They are both bottom dwellers of necessity, although they take

occasional excursions into the superambient water, but quickly

fall back, from the force of gravity, to the bottom. These excur-

sions into the superambient liquid are effected by the motion of

the caudal fin from side to side. This fin is the main organ of

locomotion used by all fish-like vertebrates for progression through

the water.

When amphioxus strikes the bottom after such an excursion,

it lies quietly upon its side, since it is unable to coil its body suf-

ficiently to lie on its ventral edge. Most of its life it passes buried

in the sand. ‘To enter the sandy bottom in which it lives, it first

makes an excursion into the superambient water and then descends

head first upon the sandy bottom, boring its way among the parti-

cles of sand. When swimming it maintains its body in the dorso-

ventral position. :

No. 470] UNITY OF GNATHOSTOME TYPE 83

In the case of the Bdellostoma we have a very different con-

dition. The Bdellostoma possesses a body remarkable for its

flexibility and its elasticity, and is fitted not only to swim in a

dorso-ventral position, but during life, when it rests upon the

bottom, always does so with a dorso-ventral orientation. While

amphioxus shows a distinct inability to orient itself and main-

tain equilibrium in this position for any but the shortest periods

of time, Bdellostoma exhibits in a high degree the capacity to

maintain its position with ease, accuracy, and for an indefinite

period. This capacity for the equilibration of its body without

the possession of paired appendages is both remarkable and de-

serving of more careful study than has yet been given.

With the possession of a simple ear, the tubular portion of

which lies in one plane of space, and with the lack of equilibrating

paddles in the form of pectoral and pelvic appendages, Bdellostoma

maintains its position while in motion with at least as great pre-

cision and as great apparent ease as any of the vertebrates possess-

ing paired appendages.

It is clear, then, that it is not the necessity jor the equilibration

of the body that has brought about the development of the paired

appendages in the vertebrate stock.

Since the formation of the paired appendages in all other water

dwellers besides fishes is for the purpose of moving the body over

the bottom, that is locomotion, it becomes very probable that the

fish fin is a secondary structure, derived from the primitive pedal

appendages, which were used by the ancestral form exclusively

for locomotion.

This effectively depen the theory of Gegenbaur of an

ancestral archipterygium, and the Thatcher-Balfour lateral fin-

fold theory, and it removes from the field of vertebrate morphology

one of the most difficult problems which it has been called on

to solve, by simplifying the conditions of the problem.

While Bdellostoma is able to swim with ease, accuracy, and

precision, and thus change its position in space either for the

purpose of capturing prey, avoiding its enemies, or seeking a

new position upon the bottom, it is not able to progress upon the

bottom except by using the same swimming motion of its caudal

region which enables it to progress through the water. It cannot

84 THE AMERICAN NATURALIST [Vor. XL

be said, however, to possess the power of locomotion except by

swimming or springing. Undoubtedly the next step in the trans-

formation of the Bdellostoma-like body of the ancestral Gnath-

ostome was the gradual formation of pedal appendages, which

enabled it to move bed ipia. and symmetrically over the

bottom.

It is just as erroneous to maintain any hypothesis which would

derive the paired appendages of the Amphibia, for example, from

the paired fins of fishes as it is to maintain the claim that the

pectoral appendages (arms — forelegs) of land vertebrates are

derived from the wings of birds.

When we consider thé structure of the nervous system we are

again brought face to face with the fact that amphioxus represents

a developmental stage in the central nervous system repeated by

other members of the vertebrate stock. Its nerve cord possesses

all the relations to the other main organs of the body that are pos-

sessed by the central nervous system of: other vertebrates. It

lies immediately above the dorsal surface of the notochord in the

hollow skeletal tube composed of a connective tissue membrane,

in the walls of which, however, no chondroidal tissue is formed,

and in which no calcareous matter has at any time been deposited,

but this condition of the protective tube of the central nervous

system is reproduced in the development of all the other verte-

brates, from the amphioxus to man. ‘This tube is not surrounded

by skeletal structure in the amphioxus, but it is perforated with

lateral openings made through its lateral face for the exit of the

nerves passing out from it and entering it. In this it is also in

harmony with the conditions found in all other vertebrates.

In the antero-posterior direction, the nerve tube is divided

into two main parts, as in all other vertebrates, a brain and a

spinal cord. ‘While there are differences of histological value

between the spinal cord of amphioxus and higher forms, this dif-

ference is hardly greater than exists between species of the higher

vertebrates above it.

We may dismiss further consideration of this part of the nervous

system with the statement that it is in every respect a vertebrate

spinal cord. When we come to consider the structure of the

brain, however, we find a simplicity in the arrangement of the

No. 470] UNITY OF GNATHOSTOME TYPE 85

parts, which has until recently been an obstacle to most zoölogists

in establishing the homologies between the amphioxus brain and

the brain of the Craniata, and even to-day very few anatomists

know enough about the structure of amphioxus to m able to

establish the homologies which are existent.

Apparently the first zoölogists to note the presence of the am-

phioxus brain were Leuckart and Pagenstecker, who homol-

ogized the entire brain vesicle of amphioxus with four ventricles

of the Craniata.

Owsjannikow later held the same view. In 1858, Professor

Huxley, after careful examination, decided that the amphioxus

neuroccele was the equivalent of the oe of the

Craniata.

In 1860, Wilhelm Miiller concluded that it corresponded with

the thalamencephalon and the prosencephalon of the ‘Craniata.

He further determined the location of the pigment in the anterior

end of the brain tube and found that the pigment granules were

located in the anterior ends of the brain cells. He also discovered

that the olfactory pit was connected with the anterior end of the

brain.

In 1861, Langerhans discovered the true relation of the olfac-

tory epithelium of the olfactory tubercle of the brain. He decided

that the va ames brain included the whole of the primitive

Craniate brain.

In 1891, I described in a brief way some of the anatomical fea-

tures of the amphioxus, giving the following account of the brain.

“The anterior end of the neural axis of amphioxus is a brain and

corresponds with a certain definite portion of the brains of other

vertebrates. Its anterior wall is the homologue of the lamina

terminalis of other vertebrate brains, and the anterior portion of

its unpaired ventricle is the thalamoccele:"'

“I would define the vertebrate brain as follows: the ‘vertebrate

brain' is that portion of the anterior part of the axial nerve cord,

associated with organs of special sense, containing an enlargement

of the central canal, which is carried out into all structures formed

by the outgrowth of the brain wall. Its walls contain the prin-

cipal centers for the-coördination of sensations and movements.

All further additions to: thi Rune: brain (npe are (beim

86 THE AMERICAN NATURALIST [Vor. XL

in responseto the-demands of the organs of special sense, with

which is associated extension of the coordination apparatus. With

such additions we have the compound brain of all other known

vertebrates up to man, inclusive.”

“Reasons why the anterior end of the nerve cord of Amphioxus

is a brain. It is a brain because: —

It forms the anterior termination of the neural axis.

2. It stands in intimate relation to the sense organs, eye, and

nose.

3. It gives off a: least two pairs of sensory nerves provided with

peripheral ganglia. | :

4. It possesses large groups of ganglion cells forming centers of

coördination.

5. It possesses an enlarged section of the central canal in the

form of an unpaired ventricle with three well marked

diverticula — two optic, one olfactory.

6. It is the largest part of the nervous system, at a time when

the massive musculature and branchial apparatus of the

anterior middle fourth of the body have not reached the

stage requiring much enlarged central accommodations.

7. It shows in young larve growth to such an extent as to cause

a ventral flexure of the chorda, while the brain itself bends

downwards and so produces a “ cranial flexure.”

8. It shows in all other details of structure that it is not simply

the anterior end of the spinal cord, but a brain.

9. It shows in a larval stage, soon after the differentiation of

fibers in the neural axis (larvee with one gill slit), a marked

differentiation into ganglionic and fibrous regions, and the

boundaries of the unpaired ventricle as well as of the lamina

terminalis are distinctly marked out. There is then a ven-

tricular segment of the brain reserved for the special sense

organs. ‘The fibers appear simultaneously with the forma-

tion of the pigment spot, and are in all probability the

ways by means of which the sensations from this special

sense organ are conveyed backward to the motor centers.

10. Since amphioxus is a vertebrate, these relations must have

direct and important bearings on the phylogeny of the

vertebrate brain and head, and will afford us invaluable

aid in clearing up these intricate problems.”

No. 470] UNITY OF GNATHOSTOME TYPE 87

“The large collections of ganglion cells just posterior to the

thalamoccele are homologous with the medullary nuclei of other

vertebrates, since their connections show them to be centers for

the control of the branchial apparatus, and the sensory and motor

structures lying in the territory of the gill basket, e. g., centers of

respiration, deglutition, etc.”

“ The ontogenetic changes of the neural axis in other vertebrates

carry the brain through the condition which in amphioxus remains

permanent as the adult brain.”

As regards the eye, I announced in 1891 that the eye-spot of

amphioxus — that is to say, the unpaired but bilaterally symmet-

rical patch of epithelial cells lying in the lamina terminalis of the

amphioxus brain — is the forerunner of the vertebrate eye, and

that, as regards its physiology, it was not a visual organ nor an

organ of sight, but an organ for the perception of the variations

in the intensity of light.

This pigmented patch of epithelium occupies the same position

in the adult amphioxus that the unpaired but bilaterally symmet-

rical patch of pigmented cells in the embryo sturgeon, as described

by Kupffer, and in the embryo of Galeus, as observed by me, does

with reference to the lamina terminalis of the brain of these forms.

In both the latter cases the pigmented patch is converted into

the recessus opticus, and the recessus opticus gives rise by a proc-

ess of evagination to the two optic vesicles.

Amphioxus, therefore, presents us with an adult condition

which is represented in the higher vertebrate form by the simple

condition of the brain wall in the earlier stages of the development

of the nervous system.

For a fuller discussion of the anatomical conditions present in

the adult amphioxus see my paper (loc. cit., pages 238 to 234).

It is clear from this description of the lamina terminalis in the

embryos of the sturgeon and of the dog-fish that the early stage

of the eye in fishes is truly comparable, indeed is homologous,

with the eye organ in amphioxus and is developed in identically

the same way. As I have already pointed out, the pigment in the

eye of the amphioxus lies in the inner end of the cells forming the

anterior end of the neural tube.

In the sturgeon this pigmented area on the inner face of the

88 | THE AMERICAN NATURALIST [Vor. XL

anterior brain wall is subject to the evagination process, being

carried out with the cells of the recessus opticus. s;

My conclusions with reference to the eye of amphioxus were

based upon a very extensive study of the eye of both the old and

the young of amphioxus, and I was able to show that there is a

great diversity in the form of the pigment area in different mem-

bers of a series of individuals and that there is a tendency for the

pigment area to divide symmetrically on either side of the —

line.

Of greatest moment, therefore, are my idit € those

of Kupffer which show that the pigment to be later used in the

retina of the eye is first of all laid down in the inner ends of the

cells of a primitively unpaired, even though bilaterally symmetrical,

plate of cells which evaginates from the brain as the recessus opticus.

Minot attempts to homologize the vertebrate eye and optic tract

with the highly differentiated arthropod eye, supra-esophageal gan-

glion and the cireumesophageal nerve ring, but the idea that the -

visual organ of the vertebrates is to be sought for in such a spe-

cialized organ as the compound 7. of arthropods is eier

by morphological facts.

The nose in amphioxus remains in the form of a suits epithe-

lial pit, whose apex is connected with or is in contact with the

anterior end of the brain.

This pit is the so called sinus olfactorius impar, being the

remains of the anterior neuropore. The right and left walls of

this conical pit are thus morphologically equal, and, notwith-

standing the fact that the pit is later pushed to one side by the

growth of the base of the median fin-fold, we must hold that it

is bilaterally symmetrical both in origin and in adult life and is

strictly comparable to the plate of cells which evaginates from

the anterior end of the brain of Bdellostoma and of the sturgeon,

and which has been conveniently called the unpaired nasal plate.

It has long been accepted that the nasal epithelium of the

_ Gnathostome vertebrate is laid down as a pair of bilaterally sym-

metrical plates in the embryo and continues paired throughout

life, while in the Cyclostome it is laid down in an unpaired con-

dition and ever remains so. Nothing could be more incorrect,

for the plate in some Amphibia is identical with that in the Cyclo-

No. 470] UNITY OF GNATHOSTOME TYPE 89

stomes. It is a single patch, of cells symmetrically placed with

reference to the sagittal plane of the body. In reality it is a double

patch, although the indifferent tissue, which later forms a septum,

has not at this stage developed.

It is said that in Acipenser embryos a median unpaired nasal

plate precedes the paired nasal organ. ‘This being the case, we

have all the more reason to consider the Marsipobranch nose a

paired structure, even though it appears to develop from an

unpaired plate.

There is certainly no truth in Haeckel’s dictum that “the

. pharyngo-nasal canal [of Myxinoids] is a secondary acquirement

in connection with parasitic habit.”.

Notwithstanding that much has been said about the naso-

pharyngeal tube of the Myxinoids, the full significance of this

structure has not yet been made out. While it at first seemed to

be an organ at the height of its developmerit in Bdellostoma, the

embryological evidence would indicate that it is a very old struc-

ture. We should not forget that in, the Petromyzontes it is

already closed off from the pharynx, and that in all other verte-

brates it arises in a very early stage of embryonic life as a naso-

hypophysial invagination of the ectoderm towards the mesenteron.

It would thus seem to be on the verge of extinction in the Cyclo-

stomes. No other stages of its development are known to us.

The total absence of an auditory organ in amphioxus is held

by certain zoölogists to be a difficulty in the way of accepting this

animal as an ancestor of the vertebrate stock.

They point out that in the tunicates, especially in the Appendi-

cularia, there is an otocyst with inclosed otolith, which sup-

posedly serves as an organ for the perception of wave motion in

the water. It is also held that, since the tunicates stand in genetic

relationship to the vertebrate stock, it is very unlikely that any

form intermediate between them and the vertebrates would

entirely lack an auditory organ. The error in their reasoning

lies in the fact that they assume that the auditory organs of the

tunicates and the vertebrates are homologous structures.

This is not the case, as all the evidence, both morphologic and

ontogenetic, clearly proves. The vertebrate auditory organ is

a neomorph arising within the vertebrate stock, from a sense-

>»

90 THE AMERICAN NATURALIST [Vor. XL

organ rudiment entirely absent, so far as we yet know, from the

tunicates. So that the absence of an ear from amphioxus is fully

accounted for, at least in so far as relation to the tunicates is con-

cerned. The tunicate ear is, in a strict sense, an otocyst, and

not an ear.

With reference to the segmentation of the body of amphioxus,

all the evidence seems to point to the ancestral character of this

segmentation in relation to mesodermic segmentation of the

higher vertebrate forms, with the exception of one peculiarity,

which is probably palingenetic in its nature, but which, so far as

we know, does not occur unmodified in any other vertebrate. I

refer to the origin of the mesodermic segments from two bilaterally

placed hollow pouches pushed out from the mesenteron.

From the many indications which have been discovered by

numerous investigators, the mesoderm in the higher forms follows

this plan of origin, but the architecture of the transformation is

coenogenetically very much shortened and due as in the

case of many other organs of the body.

There is no occasion to dismiss all the uU edd indications

preserved in the higher forms which indicate that this method

of origin was the primitive one, simply because complete and

well formed diverticula are absent from the ontogeny of the

mesoderm in all vertebrates above amphioxus that have yet been

investigated.

Regarding the suggested affinity between amphioxus and the

annelids in this matter of the segmentation of the mesoderm,

the unprejudiced mind will not hesitate to make the conclusion

that it is far less intimate than the relationship already described.

The difficulties surrounding the establishment of the homology

of the reproductive organs of amphioxus with those of the higher

vertebrates are certainly not solved by any reference of the verte-

brate stock to the annelids as ancestors, for the difficulty com-

plained of by Minot that the reproductive organs appear seg-

mentally in amphioxus, but non-segmentally in other vertebrates,

is only increased by carrying the ancestral vertebrates back to

the annelids, for here the segmental arrangement of the gonads

is even more primitive and is accompanied by many annelidan

characters of the other organs of the body; which carry us farther

No. 470] UNITY OF GNATHOSTOME TYPE 91

than ever away from an explanation of the origin of the internal

sexual organs of the vertebrate body. Certainly, when we have

to choose between annelids and amphioxus for an ancestor of

the vertebrates, it would be giving up much we have already

gained to go back to the vermian type when we have an animal

such as amphioxus, possessing many of the vertebrate characters

already developed and showing a stage of organization which no

one can for a moment doubt is immediately below that of the

vertebrates and far removed from that of the annelids and tunicates.

It is good occasionally for the zoölogist to view in the large and

in perspective the whole animal and to take note of the interrela-

tionship of all its parts, together; in other words, to take a “ bird’s-

eye view" of the form being studied in order that minute and

occasional differences, which our incomplete knowledge does

not yet permit us to explain, shall not be unduly magnified and

thereby be given an importance entirely unwarranted, and thus

prevent our establishing the homologies and recognizing the real

genetic relationships of the form in question. Much that has

been said about amphioxus in recent years has been in the nature

of zoölogical quibbling, a playing with non-essentials and an ignor-

ing of the fundamental facts of the anatomy and development of

this creature.

The intestinal tract of amphioxus also represents an ancestral

condition, which is passed through ontogenetically by higher verte-

brates. The liver pouch always arises as an unpaired divertic-

ulum of the mesenteron, which later becomes established as a

pair of diverticula higher up in the phylum.

As regards the other features of the intestinal tract, they remain

in a very primitive condition, and in the Cyclostome we have a

decided advance towards the condition occurring in higher forms.

In the Cyclostome the liver becomes a massive gland, with the

characteristic vertebrate structure, but neither amphioxus nor the

Cyclostomes possess a pancreas.

The mouth in amphioxus is extremely primitive and shows no

traces of skeletal structures which may yet be safely homologized

with the maxillary and mandibular appendages of the Cyclostomes

and the vertebrates above them.

The endostyle, which exists in a high state of development in

amphioxus and which is well preserved in the larval Ammoccetes,

92 | THE AMERICAN NATURALIST [Vor. XL

possesses as its function the collection and transference of food

to the pharynx. During the transformation of larval Ammocoetes `

into the adult Petromyzon the organ is functionless. Beginning

with the adult Cyclostome, and from there on throughout the rest

of the vertebrate series, its remnant forms the thymus gland.

As regards the excretory organs of amphioxus, the researches

of Boveri show that they are segmental in nature and that each

tubule opens upon the surface of the body, no collecting duct being

formed. Even on the theory of the annelidan origin of the ver- :

tebrates this is a stage of development through which the verte-

brate ancestors must have passed, and instead of being an argu-

ment against the close genetic relationship of amphioxus to the

vertebrates above it, it is one of the best examples we have in all

zoólogy of the persistence of an extremely primitive condition of

an organ, even after the general advancement of the body, in a

morphological sense, makes the presence of such segmental organs

appear out of place and not in harmony with the mage of ea

ment of the organism as a whole.

A similar instance of the persistence of primitive excretory

organs in the adult condition is furnished by Bdellostoma, the

only vertebrate which possesses a functional pronephros in the

adult condition, and when we compare the adult pronephros of the

Bdellostoma with the ontogenetic condition of the pronephros as

seen in mammals and in birds, we recognize at once that the dif-

ferences between these two stages are greater than the differences,

for example, which we find between the mesodermic segmentation

of amphioxus and other vertebrates or the segmentation of the

reproductive organs of the same two forms.

So that this evidence, as well as all that I have previously brought

to notice, points to amphioxus as the nearest living form among the

ancestors of vertebrates.

A glance at the information contained in the table given below

will serve as a basis for comparing Bdellostoma with amphioxus,

on the one hand, and with the Mer vertebrates, on the mess;

Table of some of the primitive characters 49) of: PCR is

which are embryonic (e.), for higher wariahentee: >

1. Notochord. (p. e.): PEecod que

2. Andits extension to the hypophysis. (p. e.)

No. 470] UNITY OF GNATHOSTOME TYPE 93

3. Membranous skeleton of Bdellostoma. (p. e.)

4. Simple heart. (p. e.) |

5. Cranial aorta. (p. e.) (Subcordal aorta.)

6. Peritoneo-pericardial cavity. (p. e.)

7. Subintestinal vein. Ventral vein of amphioxus. (p. e.)

8. Passage of subintestinal 7 Persistent subintestinal vein,

vein through liver with- 2 which passes around portal

out capillary net (p. e.) L system.

9. Gill arteries correspond to gill arches, not to hemibranchs.

(P-

10. Vein from pronephros to right cardinal vein. (p. e.)

11. Blood from anterior body walls passes into portal system.

(p. e.) |

12. Contractile portal heart. (p.)

13. Origin of carotids from lateral branchial commissure. (p. e.)

14. Segmental disposition of somatic and renal artery and veins.

(p. e.) -

15. Frequent anastomosis between post. card. veins. (p. e.)

16. Inferior jugular veins. (p. e.)

17. Large number of gills up ¢ Functional branchial vessels;

to 14. (p.e) functional branchial bars or

cartilages.

18. Their reduction during ontogenesis. (p. e.)

19. Functional pronephros. (p. e.)

20. Absence of genital ducts. (p. e.)

21. Brain. (p. e.) :

22. Cranial and spinal nerves — separation of motor and sensory

branches. (p. e.) :

When we compare these characters of a Craniate with the con-

ditions obtaining in amphioxus, we find a surprising agreement

between them. ` |

I think, from the presentation of facts just made, it is clear that

amphioxus belongs to the ancestors of the present day vertebrates.

It is, however, neither a Craniate nor.a Gnathostome, and it is

separated from all the other forms. by a zoölogical gap which we

cannot yet adequately measure, but which is very large. Let us

now pass to a consideration of the relationships of the Craniate

Vertebrata.

94 THE AMERICAN NATURALIST [Von XL

Let us assume, with Haeckel, that the Prospondylia are the stock

from which the Leptocardia and the Archicrania both arose.

From the latter hypothetical group are developed all the Craniate

forms which, down to the present time, have been classified in two

main divisions: the Cyclostomata and the Gnathostomata.

In 1894, I showed that the so called tongue apparatus of the

Cyclostome fishes, particularly of the Myxinoids, was developed

by a transformation of the jaw apparatus from the maxillo-man-

dibular apparatus of some Gnathostome ancestor, and these views,

together with the anatomical evidence supporting them, were

printed in the Journal of Morphology, vol. 17, and in the Bulletins

of the University of Cincinnati, vol. 1, nos. 1 and 2.

The development of the mouth of Bdellostoma and the pre-oral

and postoral bars (the maxillary and mandibular arches) respec-

tively in the early stages of Bdellostoma, before the formation of

the tongue apparatus, adds further corroboration of the accuracy

of the interpretation of the homologies of the cranio-facial appa-

ratus of the Marsipobranchi.

With the discovery of the jaw apparatus in the Cyclostomes,

the most essential character used by systematists for the separa-

tion of this group from the Gnathostomes disappears.

Many other characters, however, of which perhaps the absence

of paired appendages is the most noteworthy and important, re-

main as a sufficient ground for a very distinct separation of these

forms from the rest of the vertebrates.

But the group Gnathostomata must now include the Marsipo-

branchi as well as all the forms hitherto included, so that, as our

classification now stands, all the Craniata are Gnathostomes, and,

as before, the only living Acraniate is amphioxus.

The solution of the problem of the origin of the cranio-facial

apparatus is thus pushed back upon the extinct vertebrate forms

which fill in the gap between the common ancestor of amphioxus

and Craniata. Possibly paleontology may bring us the needed

information, or it may be that the embryology of some form yet

unstudied will disclose the method of the transformation of the

acraniate or agnathous into the craniate or gnathostome head.

CINCINNATI, OHIO

OLD AGE IN BRACHIOPODA— A PRELIMINARY

STUDY

H. W. SHIMER

Tue following paper was prepared as the result of studies pur-

sued at Harvard University under the direction of Professor R. T.

Jackson, to whose oversight and suggestive criticisms the writer

is indebted. Thanks are also due Mr. R. H. Willcomb of Ipswich,

Mass., for his kindness in taking the photographs.

In this study we have made use of the fine collection of the

Student Paleontological Department of Harvard University, the

collections of the Boston Society of Natural History, and those

of the Massachusetts Institute of Technology. Unless otherwise

stated, the specimens referred to are in the Student Paleontological

Laboratory at Harvard University. Those from the Massa-

chusetts Institute of Technology are either still in that institution

or have since been transferred to the Boston Society of Natural

History.

This paper aims to summarize the principal characters which

accompany old age in brachiopods, to illustrate them with some

typical examples, and to present a few suggestions as to their

origin and meaning.

Following the present usage, we employ the terms, nepionic

for the larval or postembryonic stage of an animal’s individual

development; neanic for the immature or adolescent; ephebic

for the mature or adult; and gerontic for the senile or old. Each

one of these is further subdivided into three substages by the pre-

fixes, ana-, meta-, and para-, denoting the beginning of a given

stage, its culmination, and its decline (Hyatt, 94, pp. 390-397;

93, pp. 93-108).

SENILE CHARACTERS

Senility is expressed in the shell by one or more, frequently all,

of the following characters:—

96 THE AMERICAN NATURALIST [Vor. XL

1. Lamellosity of Growth Lines.— The concentric growth lines

become more closely spaced and lamellose, with a tendency to

pile up at the lateral and anterior borders of the shell.

Examples: a pedicle valve of Laqueus californicus Koch, No.

.1.— A seni ile individual of Laqueus californicus Koch from Catalina Island,

com Old age is indicated by the lamellosity of the concentric growth

of curvature. The resorption of the umbo by the pedicle is likewise shown.

0. 71 rvard.

Fie. 1a.— A different view of the individual seen in Fig. 1, showing resorption of

the umbo and of the deltidial plates by the pedicle.

715, up\to and including its mature growth, a length of 40 mm.,

has only one or two strongly marked growth lines, while on its

Fic. 2.— A side view of the individual seen in Fig. 1, showing anteriorly the

change in the angle of curvature.

No. 470] OLD AGE IN BRACHIOPODA 97

gerontic portion there are at least eight in a length of but 10 mm.

(Figs. 1 and 2.)

A specimen of Atrypa spinosa Hall, No. 499, has in its mature

or ephebic stage a length antero-posteriorly of 30 mm. or of 36

mm. measured on the curve of the pedicle valve. In succeeding

growth originated a change in the angle of curvature at the an-

terior portion of the shell, indicating old age (see below). From

the umbo up to and including the mature portion of the shell

there are 24 well marked growth lines about equidistant; on the

gerontic or deflected portion there are nine growth lines in a

space of but 4.5 mm. Thus in old age the growth lines become

crowded, as one occurs in every 0.5 mm., while in the previous

growth one occurred in only every 1.5 mm. The piling up of

the growth lines was caused by their continued production unac-

4 3

Fic. 3.— A very large senile individual of Atrypa spinosa Hall from the Hamil-

ton of Eighteen Mile Creek, New York, vun "WIDE the change in the angle of

curvature, the groove at the junction of the valves, and the lamellose pers

tion of the growth lines upon the tradi beth of the shell. No. 499,

Harvard

Fig. 4.— A fully mature lioe 2 Abend spinosa Hall, on which none of the

above gerontic features ap

companied by any considerable growth of the shell in the anterior

direction (Fig. 3

A Lower Helderberg specimen of Atrypa reticularis (Linné),

No. 641, shows 12 growth lines on the gerontic portion in less

than 5 mm. This is after the abrupt deflection while the preced-

ing portion of about 21 mm. in length also had only 12.

2. Change in the Angle of Curvature.— T his often results in

a groove at the junction. of the two valves. An abrupt change in

98 THE AMERICAN NATURALIST [Vor. XL

direction occurs at the lateral and anterior borders of the shell so

as to produce maximum growth almost or completely at right

angles to the plane of separation of the valves. This change is

frequently so great as to produce a reéntrant groove of greater

or less depth at the junction of the valves, at the lateral and an-

terior portions of the shell. The groove results from the failure

of each successive growth line to build out as far as the preceding

one, and thus results in bending in the edges of the valves so that

they meet in a depression.

Examples: in a pedicle valve of Athyris spiriferoides (Eaton),

No. 498, the first lamellose growth lines appear after the shell has

attained a length of 22 mm. and a width of 26 mm. At this period

in growth the shell not only ceased to increase in width at the

cardinal angles but actually decreased and so produced a groove

E d

5 6

Fic. 5.— Athyris adeste eec A t individual from the Hamilton

group of Eighteen Mile Creek, New York.

Fic. 6.— A senile ME. o Athyris spiriferoides (Eaton) from the Hamilton

of Eighteen Mile Creek, New York. erontism is well shown here in the

change in the angle of curvature and the conspicuous groove at the junction

of the valves. No. 498, Harvard

1 mm. in depth (Fig. 6). 'The change in the angle of curvature

took place at the anterior portion of the valve later than at the

cardinal angles.

In a specimen of Laqueus californicus, No. 715, measuring 45

mm. in length by 35 mm. in width, the change in the angle of

curvature in old age at the sides of the shell is about 45?, and at

the anterior portion is much less. This specimen also shows a

shallow, broad groove at the cardinal angles (Figs. 1 and 2).

A slight groove is also developed at the cardinal angles of a

No. 470] OLD AGE IN BRACHIOPODA 99

specimen of Rhynchotrema capax (Conrad), No. 142, and of

Atrypa spinosa Hall, No. 499 (Figs. 8 and 3). In these speci-

mens, however, the groove does not extend to the anterior por-

tion of the shell as it does in some.

3. Rotation of the Umbos toward Each Other.—T his results

in greater gibbosity of the shell.

As shown above, the anterior growth of the valves in old age

Fia. 7.— Rhynchotrema capaz (Conrad) from the Hudson River group of Cincin-

nati, Ohio. A mature form.

Fic. 2 A Aig senile ee of Rhynchotrema capax (Conrad) from the Hud-

n River group of Cincinnati, Ohio. Senility is shown in the lamellose

Benin nie and in the sn gibbosity. No. 142, Harvard.

is at a more or less abrupt angle to the previous growth. This

gerontic growth thus tends to push the edges of the ephebic shell

farther and farther apart, and causes the valves to rotate outward

on the axis of the hinge line. This rotation brings the umbos

closer and closer together until often the beak of the brachial

9 10

` Fie. 9.— A fully mature form showing in the pronounced growth varices the

beginning of senility. Platystrophia lynx (Eich.) from the Hudson River

Fig. 10.— An advanced gerontic form of Platystrophia lynx (Eich.) from the Hud-

n River wir of Cineinnati, Ohio. Old age is especially shown here xo the

strongly lamellose growth lines and in the closely approximated u

No. 1011. M. L 7.

valve encroaches on the delthyrium of the pedicle valve to such

an extent as to block the original pedicle opening entirely (Figs.

100 THE AMERICAN NATURALIST [Vor. XL

8 and 10). As long as the pedicle remains active it will resorb

the umbo of the pedicle valve as fast as the brachial umbo en-

croaches upon it, thus keep-

ing a passage open for itself

(Fig.11). From this rota-

tion of the valves there re-

sults a lengthening of the

dorso-ventral axis of the

shell. This gives it a gib-

bous appearance which is

seen even in forms that are

in maturity flat and thin, as

Fia. 11.— Rhynchotrema capax (Conrad). Se Rafinesquina alternata. This

son Hiver group aa trou re a great increase in thickness

of the umbo, kept its pedicle passage open pari is shown in Figs. 3, 5, and

passu with the rotation of the umbos toward . :

each other. No. 1156, Harvard. 6, and also mn the following

measurements :—

Rafinesquina alternata (Figs. 12 and 13). Adult, No. 1912,

M.I.T. Length, 32 mm.; breadth, 41 mm.; thickness, 3.5 mm.

Old age, No. 128. Length, 39 mm.; breadth,51 mm.; thickness,

11 mm.

Rhynchotrema capax (Figs. 7 and 8). Adult, No. 1913, M. I. T.

Length, 22 mm.; breadth, 21 mm.; thickness, 26 mm.

Fic. me — Mature individual of Rafinesquina alternata (Emmons) from the Hud-

n River ig f Cincinnati, Ohio.

Fic. e" — A la erontic individual of Rafinesquina alternata (Emmons) vius

the H leon hoes p of Cincinnati, Ohio, indicating een in the lamel-

losity of the conc a growth lines, in the dungen angle of curvature, an ni

in the greater gibbosity of the shell. No. 128, Harvard.

No. 470] OLD AGE IN BRACHIOPODA 101

4. Flattening-out of Plications.—In old age the plications (ribs)

tend to flatten out and disappear. ‘Their presence is usually

indicated on the gerontic portion of the shell by zigzag lines of

growth, though the surface of the shell is at this area smooth.

This is seen in Rhynchotrema capax, Platystrophia lynx, Tropi-

doleptus carinatus, Spirifers, etc., and holds true in all specimens

examined (see p. 117).

Examples: in Rhynchotrema capax, No. 142, from Cincinnati,

Ohio, the pedicle valve has during maturity 15 ribs; during meta-

gerontism it has 11, and at the last growth before the death of

the animal there are none, although zigzag growth lines represent

them. The brachial valve has during maturity 14 ribs; during

metagerontism, 10, with none at the death of the animal.

In Spirifer oweni, No. 57, from the Hamilton of Clark Co.,

Indiana, the ribs become broader and lower until in extreme old

age they, as well as the zigzag growth lines at the edge of the shell,

have almost entirely disappeared even at the anterior portion of

the shell (see p. 117 for further discussion).

The ribs disappear earlier and more completely from the brach-

ial than from the pedicle valve. ‘This was noticed especially in

Terebratella plicata Say, Tropidoleptus carinatus (Conrad), Meek-

ella striatocostata (Cox), Spirifer mucronatus var. thedfordense

Shimer and Grabau, and Rhynchotrema capax

(Conrad). This character is often only faintly

marked; its presence is first noted at the cardi-

nal angles. Raymond (:04, p. 128), also notes

the more nearly complete obliteration of the

plications on the brachial valve in Tropidoleptus

carınalus.

5. Disappearance of Median Sinus and Fold.

— The median sinus and fold tend to flatten out

and disappear in a few observed species.

Examples: in Ambocelia umbonata N showing the dis-

(Fig. 14), the median sinus disappears in old age. bt eg

In Bilobites varicus (Conrad) there is also a ten-

dency to obliterate the marginal sinus. This is shown in a series

of shells, No. 4, from the Lower Helderberg of Clarksville,

Albany Co., New York (Fig. 15). For further examples see

also Beecher (:01, p. 403).

102 THE AMERICAN NATURALIST [Vor. XL

In some species the median sinus appears to become more ac-

centuated with age. For example, Athyris spiriferoides shows

well this accentuation of the sinus with hardly any corresponding

. development of the median

fold, while in Celospira gra-

baui Shimer, both sinus and

Fia. 15.—Series showing gradual obliteration fold are developed (Shimer,

Rd ca NN jj inen : 04, P 253

Helderberg of Clarksberg, New York. No. 6. Enlargement of Cardi-

nal Angles.— The cardinal

angles, that is, the angles made at the cardinal extremities

between the hinge line and the sides of the shell, enlarge during

senescence.

Examples: a specimen of Rafinesquina alternata, No. 128, has

just preceding senescence, a cardinal angle of 87°. This increased

to 99° during old age (Fig. 13).

A specimen of Spirifer mucronatus var. thedfordense, No. 405,

has at the close of the neanic or Spirifer mucronatus stage (Shimer

and, Grabau, :02, p. 171) a cardinal angle of 25°. "This angle rap-

idly increases as seen in Fig. 16, through the ephebic and gerontic

stages until it measures 60° at the death of the animal.

7. Reduction of Shell Index.— The shell

index, i. e., the breadth divided by the

length, becomes smaller with old age (see

Cumings, :03, p. 3). In other words the

shell becomes proportionally longer in old

age than in maturity and in this respect

approaches the nepionic condition.

Examples: a specimen of Spirifer mucro-

group of Arkona, Ontario.

: : This shows senility in the

natus var. thedfordense has during its enlarging cardinal angles

EN b and in the piled-up growth

nepionic stage a shell index of 1.77; dur- jines. No. 405. Harvard.

ing its neanic, 3.57; and during ephebic,

1.90. For further measurements and discussion of the varietal

form see Shimer and Grabau (:02, p. 174).

An old specimen of the above species, No. 405a, had during

early maturity a width of 34 mm. and a length of 14 mm., giving

a shell index of 2.43. In old age the width was 33 mm., the length

18 mm., and shell index 1.83.

No. 470] OLD AGE IN BRACHIOPODA 103

Rhynchotrema capaz, No. 142, had in maturity a width of 18

mm., a length of 17 mm., giving a shell index of 1.06. In old age

the width was 20 mm., the length 23 mm., and shell index 0.87

In Rafinesquina alternata, No. 128, the mature shell measured

42 mm. in width, 30 mm. in length, and the shell index was 1.40;

the senile shell was 51 mm. wide by 39 mm. long with a shell

index of 1.30.

8. Modification of Pedicle Opening.—a. The pedicle opening

may be enlarged during growth. As the animal increases in size

the pedicle normally increases in diameter if it continues attached.

The resulting growth of the pedicle may resorb the surrounding

shell (the deltidium or deltidial plates and umbo) and thus enlarge

its opening. This is especially conspicuous in the Terebratuloids.

In some shells resorption is'made doubly necessary if the pedicle

would continue to exist, for the rotation of the umbos toward

each other would otherwise soon cut it off. This condition is seen

well in some specimens of Rhynchotrema capaz.

Examples: a specimen of Laqueus californicus, No. 715, is a

senile individual as indicated by its lamellose growth lines, abrupt

deflection, and groove at the cardinal angles. The umbo shows

considerable resorption as do also

the deltidial plates (Figs. 1 and 1a).

A senile specimen of Hebertella

occidentalis Hall, No. 2, has a

triangular delthyrium 9 mm. high,

5.5 mm. wide at the hinge line,

and 2.5 mm. at the apex of the

umbo. The delthyrium, already

large in maturity with the delti- ue

dium resorbed, has been much ye e E a E

enlarged in old age; in addition Hudson River group of Cincinnati,

Ohio, showing the pedicle opening

the umbo of the pedicle valve has much enlarged through resorption of

been resorbed, destroying much !heumbo. No.2, Harvard.

more than the nepionic shell (Fig.

17). This destruction of the umbo may be partially due to

breaking as shown by an irregularity at the anterior side, but

there is no doubt that most of the opening is due to resorption

104 THE AMERICAN NATURALIST [Vor. XL >

asit has the same general smoothness and evenness. of the sides -

as the delthyrium.

In those forms of Rhynchotrema capax which continue jich

throughout life, the increasing gibbosity makes necessary, even

during late maturity, a resorption of the umbo of the pedicle valve.

But this resorption becomes very great in senile specimens, as

for example in a specimen, No. 1156, the apex of whose pedicle

valve has been resorbed anteriorly at least 1.5 mm. (Fig. 11).

The smoothness of this opening and the evenness with which it

is prolonged out from the interior of the shell show it to result

from true resorption and not from breaking.

b. The pedicle opening may be partially or completely closed.

This is accomplished :—

(1) By deposits of calcareous matter in the apex of the valve,

sometimes forming a callosity. -

Example: in Stropheodonta demissa (Conrad), No. 1914, M. I.

T., the delthyrium has been completely closed by growths that

extend from either side and meet in the middle; these form two

Fic. 18.— The interior of the pedicle valve of a mature form of Spirifer acumı-

natus (Conrad) from the Upper Helderberg of the Falls of the Ohio, showing

Fic. 19.— The interior of a pedicle valve of a gerontic individual of Spirifer

acuminatus (Conrad) from the Upper Helderberg of the Falls of the Ohio,

showing the accentuation of the callosity. No. 646, Harvard.

convex callosities on the inner or proximal side which meet in

the median line. The outside of these growths is smooth and

also the cardinal margin is wanting in the denticulations character-

istic of the rest of the shell. :

A testaceous callosity sometimes forms in the pedicle cavity,

and extends across the delthyrium (see also Hall and Gare

’94a, p. 6). This is seen in Spirifer acuminatus (Conrad), 5

granulosus (Conrad), and S. audaculus (Conrad).

No. 470] OLD AGE IN BRACHIOPODA 105

Example: in a gerontic pedicle valve of S. acuminatus, No. 646,

the callosity extends 17 mm. from the apex of the valve to the

anterior border, uniting the dental lamell® and sending off a

median portion forward between the posterior extremities of the

diduetor muscle impressions. In a mature valve of this species

there appear only faint indications of this callosity in the apex

(Figs. 18 and 19). Hall and Clarke (94a, p. 921), mention this

deposit of calcareous matter in the apex of the valve as a frequent _

condition in senile Spirifers. They also state that “the tendency

to contract the pedicle cavity and deltidium presents its extreme

manifestations in the Devonian forms of Stropheodonta, Stropho-

nella and Leptostrophia where it has become almost and some-

times quite obliterated and the entire umbonal area filled with

testaceous secretions” (Hall and Clarke, '94a, p. 919).

(2) By the encroachment of the umbo of the brachial valve

upon the delthyrium of the pedicle valve, so as partially or com-

pletely to cover it. This follows from the rotation of the umbos

toward each other in senescence as already described (p. 99).

When its original opening is thus covered, the pedicle may keep

its passage free by resorption into the umbo of the pedicle valve,

as already seen (Figs. 1, 11, 17), or may become atrophied and

disappear, leaving the shell unattached.

Examples: in a senile specimen of Platystrophia lmz, No.

1911, M. I. T., the umbos are so closely appressed that no pedicle

opening can be seen (Fig. 10). An approach to this condition

is seen in many senile Spirifers, Rhynchotrema capaz, etc.

9. Disappearance of Spines, Nodes, etc.— In old age the sur-

face tends to become smooth, thus repeating the nepionic surface

character. In all forms this is noted first at the angles and later

at the anterior portion of the shell. There is slight development

of surface ornamentation among the brachiopods beyond the

simple plications and median sinus and fold. ‘This lack is especi-

ally noticeable when we. compare this. class with the pelecypods,

gastropods, and cephalopods which are often characterized by

an excessive development of ribs, spines, nodes, etc. If, in brachi-

opods, spines or nodes are present in maturity, they gradually

become less numerous until in extreme old age they disappear

entirely (see also Hyatt, ’89, p. 20, and Beecher, :01, p. 94).

Examples are noted in Productus, Atrypa, and Ambocoelia.

106 THE AMERICAN NATURALIST [Vor. XL

Productus horridus, No. 600, 43 mm. wide and with a length of

82 mm. following the curve of the pedicle valve, has no spines

on the last added 12 mm. of the anterior portion, while the spines

had disappeared earlier from the surface at the cardinal angles

(see p. 110).

Another specimen of the same species, No. 607, has no spines

on the last added 18 mm. This disappearance of spines in old

age is also well seen in Ambocelia spinosa and in Atrypa spinosa.

In Atrypa nodostriata the disappearance of nodes from the senile

portion of the individual was noted.

10. Thickening of Valves.— This may result in the formation

of an elevated ridge about the muscular area and in the building

of a ridge just inside the margin of the concave valve in concavo-

convex forms. Both valves, and especially the pedicle valve,

thicken by interior additions. The area of maximum increase

usually extends from each side of the muscular impression to the

| cardinal angles. Sometimes, as for

example in Athyris spiriferoides, the

greatest thickening isat the lateral edges

‘of the valves. The pedicle valve be-

comes especially thickened over the

gential organs asseenin Atrypa, Spirifer,

etc.

ba a a u Examples: a pedicle valve of Atrypa

a gerontic specimen of Atrypa reticularis, No. 641, has a broad, promi-

reticularis (Linné) from the . *

Lower Helderberg near Cat- nent ridge bounding the muscular area

viden i punk "m laterally and sloping outward to a de-

ened and inflected edge of pression between it and the much

ment shige houndine the mus, thickened and inflected edge of the shell;

cular area. No. 641, Harvard. jt disappears entirely anteriorly (Fig. 20).

A pedicle valve of Spirifer acuminatus,

No. 646, shows a greatly depressed muscular area due to the great

thickening of the posterior portion of the valve on each side of

it, which slopes gradually to the lateral margins of the valve (Fig.

19).

In Platystrophia lynx, No. 3, the pedicle valve is thickened

very much at the sides of and anterior to the muscular area (see

also Cumings, :03, p. 28).

No. 470] OLD AGE IN BRACHIOPODA 107

In the above cases, as well as in all observed, the greatest thick-

ening in the interior of the valve occurs in the region of the princi-

pal trunks of the vascular sinuses, and it is in these main trunks

that in modern brachiopods the genital organs occur (for further

discussion see p. 117). In most concavo-convex and resupinate

shells the concave valve bears just inside its margin and posterior

to where the convex valve fits over it, a swollen and strongly papil-

21 22

Fic. 21.— ature brachial valve of Rafinesquina alternata (Emmons) from

the Sinn River group of Cincinnati, Ohio. No, 1, Harvard.

Fic. 22.— Th hial valve of a gerontic individual of Rafi i

(Emmons) from t dson Riv Cincinnati, Ohio, showing the

vascular verum Sog and its abrupt descent to the edge of the valve.

vard collectio;

lose ridge which extends from the cardinal angles to the anterior

portion of the shell. In the brachial valve of Rafinesquina alter-

nata the ridge has a very irregular surface and descends abruptly

to the narrow margin of the valve. This makes the interior of

the valve quite flat while the outside is concave (Fig. 22). This

submarginal thickening was also noted in Tropidoleptus carinatus

(Conrad), Strophomena rugosa Blainville, Plectambonites sericeus

(Sowerby), Chonetes granulijera Owen, Stropheodonta magniventra

108 THE AMERICAN NATURALIST [Vor. XL

Hall, and S. concava Hall. Sometimes the papille are so well

developed that they are spine-like. This was most conspicuous

in Stropheodonta magniventra, No. 1165, and in S. concava, No.

1099, M. I. T.

In the majority of brachiopods the muscular area of the pedicle

valve becomes in gerontic individuals depressed below the general

interior level of the shell through the thickening of the shell about

it, and thus frequently leaves this area translucent in its thinness

while the remainder of the shell is very thick. The area is often

strongly marked off from the rest of the valve by an elevated ridge

at times high and well defined, surrounding it. This ridge is

Fic. 23.— The pedicle f anie

Fıg. 24.— The pedicle valve of a gerontic individual san s ebertella M N

showing the high ridge defining the muscular

conspicuous in Rafinesquina alternata, Leptena rhomboidalis,

Hebertella occidentalis (Fig. 24), Eatonia peculiaris, and Hip-

parionyx proximus, in all of which the muscular area is strongly

marked off from the rest of the shell. In Spirifer acuminatus

(Fig. 19) the ridge surrounding the muscular area is merged with

the general thickening of the shell. We have not been able to

examine any senile forms in which the dental lamelle of the pedicle

valve are strongly developed and form a spondylium, as for ex-

ample in Pentamerus, Gypidula, etc. In these the muscular

area is thus raised instead of retaining its youthful position. ‘This

thickening of the valves may in a few individuals result in the

lessening of the total capacity of the body chamber. Usually,

No. 470] OLD AGE IN BRACHIOPODA 109

however, the internal thickening is more than offset by the growth `

of the margins of the valves toward each other; for even a slight

marginal growth means a large increase in the cubic capacity

of the shell.

DESCRIPTIONS OF A FEW SPECIES

The following species were chosen for description of senescence

because there were gerontic specimens of them in the collections

studied and also because they are common. Similar old age

characters were, however, noted upon all forms which showed

any approach to gerontism. When one specimen is described,

this is merely taken as a type but the characters hold true for all

the specimens of that species examined.

Rafinesquina alternata (Emmons).— A large specimen, No.

128, from the Hudson River group of Cincinnati, Ohio, was 30

mm. long when it first showed signs of old age in the appearance

of lamellosity and in the changed angle of curvature; this change

is much more noticeable on the pedicle than on the brachial valve.

The shell also increases in thickness from. 3.5 mm. in a normal

mature specimen to 11 mm. in this gerontic individual. In old-

age specimens of this species the pedicle opening is usually en-

tirely closed and if it exists, is much too small to admit the passage

of a pedicle large enough to support a shell of such a size (on this

point see also Hall and Clarke, '92, p. 141). This condition is

not, however, due wholly to senility but existed during maturity.

'The interior of the brachial valve has, extending from the car-

dinal angles around the margin of the valve anteriorly, a tumid

ridge with a very irregular surface. This descends abruptly to

the edge of the valve. For comparison of mature and gerontic

forms see Figs. 21 and 22.

Strophomena rugosa Blainville (Streptorhynchus planumbonus

Hall).— A pedicle (concave) valve, No. 582, of this species bears

just inside its edge a tumid ridge with a considerable vascular

surface, which is not developed to such an extent as in the concave

(brachial) valve of Rafinesquina alternata. This fact is interesting

as the ridge is developed in opposite valves in the two species.

'The muscular area remains translucent while the rest of the valve

110 THE AMERICAN NATURALIST [Vor. XL

becomes much thickened and more or less grooved by vascular

markings. Both valves of this species bear lamellose growth

lines. There is also a greater lamellosity in the latest built por-

tion of the deltidium and chilidium.

Productus horridus Sowerby.— No. 600 from the Lower Zech-

stein of Gera, Thuringia, is not very senile. Old age, however,

is indicated by the greater concavity of the brachial valve and

by the absence of spines from the last added 12 mm. of the ante-

rior portion. They had disappeared before this from the car-

dinal angles, showing thus the progressive advance of senility

from the cardinal angles to the anterior portion. This order of

disappearance is just what we should expect from their order of

initiation, appearing as they do at the cardinal angles before they

develop on the main portion of the shell.

Platystrophia lynx (Eichwald).— A gerontic individual of this

species from the Hudson River group of Cincinnati, Ohio, No.

1911, M. I. T., attained a length of 31 mm. before it began to

show evidence of old age in any marked degree; after this point

it added a length of 13 mm. to each valve. The senescent char-

acters noted here are: lamellosity of growth lines, flattening of

the ribs, and formation of a groove at the cardinal angles. Through

the change in the angle of curvature and the consequent growing

toward each other of the two valves, the entire shell becomes very

gibbous. The accentuation of these characters in increasing old

age may be seen by comparing Figs. 9 and 10. The cardinal angle

measures 78° at the close of the ephebic stage and 94° in the geron-

tie. Similar observations are given by Cumings (:03, p. 12).

A pedicle valve of this species, No. 3, from the Hudson River

group of Cincinnati, Ohio, shows a very pronounced thickening

on each side of and anterior to the muscular area. This area

thus appears to be very much depressed, with high, perpendicular

bounding walls. The development and relationship of this species

are very thoroughly discussed and illustrated by Cumings (:03).

Rhynchotrema capax (Conrad).— A specimen of this species,

No. 142, from the Hudson River group of Cincinnati, Ohio, after

reaching maturity when it had a length of 15 mm., became lamel-

lose at the cardinal angles and the ribs began to flatten out, while

the angle of curvature in each valve became relatively greater.

No. 470] OLD AGE IN BRACHIOPODA 111

It then lengthened the pedicle valve 8 mm. on the curve of the

shell, during ana- and metagerontism. At this point the growth

lines become still more lamellose, more of the ribs flatten out,

and a sudden increase in the angle of curvature takes place. From

this point it added 7 mm. to each valve. There is shown especi-

ally on the median sinus and folds of this latest added portion a

groove in the center of each rib on account of the changed plane

of growth. A shallow groove is formed at the junction of the

valves. This is greater at the cardinal angles since it is there

first formed and proceeds progressively anteriorly. This groove

is due in the anterior portion to the last added two or three growth

lines only. The specimen has the pedicle opening entirely filled

by the umbo of the brachial valve. Another specimen, however,

No. 1156, as large as the preceding and

representing a similarly advanced stage of

senescence, has a very large pedicle open-

ing. Mature and RER forms are shown

in Figs. 7 and 8.

Terebratula harlani Morton.— In this spe- Fıc.2

cies old age is shown in the lamellose con-

centric growth lines, the change in the angle

of curvature, the groove at the cardinal

angles, the larger cardinal angle, and the re- indicated In the Ee,

sorption of the umbo and deltidial plates. angles, reduction of shell

index, and in t

Exactly similar characters are shown in T. _zening-out of the ribs.

perovalis Sowerby y. ese last always disap-

Tropidoleptus carinatus (Conrad).— In the cardinal angles to

. . : the front of the shell.

an old-age specimen of this species, No- 5 1015 MILT

1915, M. I. T., the ribs are flattened out on

the gerontie portion and the growth lines are lamellose, irregular,

and more or less piled up. These senile characters appear pro-

gressively from the cardinal angle to the front of the shell (Fig.

25). The cardinal angle enlarges and the shell index grows smaller.

The ribs flatten out on the brachial valve before they do on the

pedicle valve. In other specimens the submarginal ridge of the

concave (brachial) valve, so characteristic of Rafinesquina alternata,

also occurs, though in a less marked degree. Raymond (:04,

PP. 126-131) discusses this species fully.

112 THE AMERICAN NATURALIST [Vor. XL

Laqueus californieus Koch.— A specimen of this recent species,

from Catalina Island, California, No. 715, shows old age in the

lamellose growth lines, the change in the angle of curvature, and

the formation of a groove at the cardinal angles, and in the larger

cardinal angles (Figs. 1 and 2). These characters also appear in

L. rubellus Sowerby, etc.

Atrypa spinosa Hall.—In a specimen Nom the Hamilton of

Eighteen Mile Creek, New York, No. 499, old age is first indicated

after a growth of 27 mm. by the sudden erowding together of the

growth lines and by the change in the angle of curvature. After

this the anterior growth through the change in curvature adds

about 5 mm. to the thickness of the shell and 4 mm. to its length

measured along the antero-posterior axis. This gives the shell

a very gibbous appearance. Senility is first expressed at the

cardinal angles as seen in the development there first of the greater

lamellosity of the growth lines, the change in the angle of curva-

ture, and the formation of a groove which does not extend far

anteriorly. The thickness of the comparatively flat pedicle valve

is much greater than that of the brachial. For comparison of

the senile characters of this specimen: with an adult form, see

Figs. 3 and 4. A pedicle valve, No. 641, shows the separation

of the muscular area from the rest of the valve by a thick, promi-

nent ridge which is especially developed at its sides, ?. e., over

the genital organs (Fig. 20). The thickened lateral edges of this

form a prominent inflected edge.

Spirifer mucronatus var. thedfordense Shimer and Grabau.—

A specimen of this species, No. 405, from the Hamilton group

of Arkona, Ontario (Fig. 16), shows old age in an increase of the

lamellosity of the concentric growth lines, the fading-out of the

ribs, the change in the angle of curvature, and the development

of a groove cardinally at the junction of the two valves. These

characters hold true in all senile specimens of this genus examined.

In S. acuminatus the greatest thickening of the valves is on each

side of the muscular area. This character appears to hold true

in all species. In some species (e. g., euryteines, acuminatus,

oweni, etc.) a conspicuous thickening (callosity) occurs also pos-

terior to the muscular area in the pedicle valve, thus separating

it widely from the apex of the valve (Fig. 19).

No. 470] OLD AGE IN BRACHIOPODA 113

N ucleospira ventricosa Hall.— Senility in this very small, Low-

er Helderberg species is shown by a conspicuous roughness or

lamellosity of the concentrie growth lines in the otherwise smooth

shell, a change in the angle of curvature, and the formation of

a reéntrant groove at the cardinal angles, the point where senility

is first indicated. No shell sufficiently senile to have developed

a groove in the ‘anterior portion was observed.

Athyris spiriferoides (Eaton).— One specimen from the Hamil-

ton of Eighteen Mile Creek, New York, No. 498, was 22 mm.

long and 26 mm. wide when senescent characters first appeared.

After that it grew 10 mm. anteriorly measured on the curve of

the shell. This growth increased the antero-posterior axis only

6 mm. The maximum width of the pedicle valve was increased

only 2 mm: though the total amount added to the width in old

age measured over the curve of the valves, was 11 mm. The

rest of the growth both anterior and lateral merely added to the

thickness of the shell. In this shell old age is expressed by the

lamellosity of the growth lines and the change in the angle of

curvature. This latter character is more especially noticed at

the sides of the pedicle valve as this valve piled up growth lines

here to a thickness of 4.5 mm. The lateral edges of the brachial

valve thickened less. A groove was formed at the junction of

the valves. The cardinal angle enlarged from 100° in the mature

shell to 125° in paragerontism (Fig. 6). This specimen shows

the normal progression of old age characters from the cardinal

angles to the anterior border, in the first appearance there of the

lamellose growth lines and of the groove. This groove at the

death of the animal had advanced only halfway to the anterior

border of the shell. A separate pedicle valve, No. 635, shows

the maximum thickening from each side of the muscular impres-

sion to the cardinal angles, with the greatest thickening at the

edge of the valve. Figs. 5 and 6 show for comparison a mature

and a gerontic individual.

CONCLUSIONS.

Minot (’91, p. 151) says very suggestively: “I think it is now

conclusively established that there is in guinea pigs a progressive

114 THE AMERICAN NATURALIST [Vor. XL

loss in the power of growth, beginning almost immediately after

birth.” This same decrease is very realistically shown in the

little gastropod, Litorina littorea, so abundant on our Atlantic

coast. his shell, in the vicinity of Boston, is very quickly at-

tacked by an alga which discolors and erodes it. So if a series

of the shells from small to large is collected at mid- or late sum-

mer before the new growth has become corroded by the alge,

the amount of that year’s growth is very distinctly shown. Such

a series shows that, while on the small specimens the year’s growth

was more than two complete whorls, in older specimens it became

progressively less until in some of the mature ones it was but 3.5

mm. Finally on the older shells growth was extremely reduced,

being on one shell only 0.75 mm. For these facts concerning

Litorina we are indebted to Professor R. T. Jackson whose series

of these shells collected from Manchester, Mass., shows the above

facts. The series is now on exhibition at the Boston Society of

Natural History. Ä

This relative decrease in growth is also shown in the crowding

of the septa in old-age cephalopods. Among pelecypods and

brachiopods the relative decrease in the amount added to the shell

is indicated in the more crowded condition of the later added

growth lines. For example, a specimen of Atrypa reticularis, No.

641, shows 12 growth lines on the gerontic portion which give

a thickness of 5 mm. while the preceding growth, about 22 mm.

long, has also only 12. Yet if the growth lines were added at

regular time intervals the gerontic stage represented as long a

period as that from embryonic through ephebic.

That the more prominent growth lines may define the shell

growth for definite periods of time is indicated in the following

examples. Buxbaum showed that Anodonta cellensis, one of the

Unionide, had two strongly marked concentric lines and hence

three sets of more faintly marked areas, and this shell was known

to be three years old (Latter :04, p. 163).

The common oyster commercially marketed is about four years

old when gathered. Blue Points, which are smaller, are three

years old. This age is broadly indicated on the shells by the

stronger growth lines. On the Litorina cited above, the new

growth is usually bounded posteriorly by a prominent growth

line. : : |

No. 470] OLD AGE IN BRACHIOPODA 115

While thus the increase in the size of the animal becomes less

and less for each succeeding growth period, a time is reached,

varying with each individual, when another factor enters and

actual decrease or shrinkage begins. The tendency of the soft

parts of animals to contract in old age is familiar to us. (See

Hyatt, 96, p. 15; Quain, :03, p. 1478). Through this tendency

can be explained many alterations in the hard parts which are

otherwise difficult of explanation.

The soft parts and especially the mantle of brachiopods, as

well as of molluscs, are so closely related to the shell (Morse, : 02,

Fig. 26.— Shell showing gerontic effects produced by injury. Laqueus califor-

nicus Koch from Catalina Island, California. No. 738, Harvard.

p. 321) that the least change in the former is expressed in the

latter. For example, a specimen of Laqueus californicus Koch,

No. 738, had the anterior portion of the mantle injured. The

scars occur in the same relative position on each valve, and the

mantle edge left a groove on the shell, indicating the scar (Fig.

26). Before the animal was injured the surface of the shell was

very smooth, showing no signs whatever of declining strength,

but as soon as the injury occurred a lessened vitality is very notice-

able in the change in the angle of curvature and in the lamellose

growth lines, simulating senescence.

A change in the angle of curvature of the shell shows that the

Soft parts of the animal have ceased to grow as fast as formerly.

When, however, we consider such gerontic individuals as Athyris

116 THE AMERICAN NATURALIST [Vor. XL

spiriferoides, No. 498 (Fig. 6), and Atrypa spinosa, No. 499 (Fig.

3), as described above, it is evident that the growth of the soft

| parts must have practically ceased, while their secreting activities

were continued, but were now almost entirely directed toward

thickening the shell (see also Beecher, :01, p. 91).

The formation of a groove at the junction of the valves means

further, not only that the growth of the mantle has ceased, but

that it is in fact growing smaller, in other words is shrinking. As

noted above in the description of Athyris spiriferoides, etc., the

width of the shell on the right and left axis is less during parageron-

. tism than it is during the earlier anagerontic stage. This tendency

of the soft parts of the animal to shrink and to express this shrink-

age in the hard parts is also well exhibited among pelecypods and

cephalopods.

The lamellosity of the growth lines in such types as Athyris,

27 28 29

Fic. 27.— The pedicle valve of a senile individual of Atrypa reticularis (Linné)

from the Lower Helderberg.of Catskill, New York. The prominent ridge sur-

rounding the muscular area occurs beneath the main vascular sinus.

Fig. 28.— The pedicle valve of Atrypa reticularis (Linné) showing the muscular

(m) and vascular impressions with the ovarian markings (0) within the main

vascular sinus of the latter. (After Zittel.)

Fic. 29.— Brachial and pedicle half of pallium of the recent Terebratulina core-

anica with the main pallial sinus and lacune filled with eggs. b, brachial

valve; p, pedicle valve; la, lacuna; m. p., main pallial sinus (after Morse).

Atrypa, etc., is caused by the relatively decreasing extent of the

successive lamella of shell growth built in old age. This as result-

ant brings about a change in the angle of curvature which in

extreme cases causes even a resultant angle of less than 90°.

The thickening of the shell on the interior often takes place

very irregularly, and leaves the surface strongly papillose. This

is well seen in the Spirifers, Stropheodontas, etc. In some Strophe-

No. 470] OLD AGE IN BRACHIOPODA 117

odontas, as noted above (section 10), these papillose protuberances

become almost spine-like.

The principal thickening in at least many brachiopods occurs

over the main trunks of the vascular sinuses (compare Figs. 27,

28, 29; see also Fig. 22). It is a significant fact that in these are

located the genitalia (Hancock, '59, p. 817). If a greater con-

traction took place there it is just in line with what we know occurs

in higher animals (Quain, :03, p. 1478). It is usually held that

“no gerontic limit is known to the reproductive time in the lower

animals" (Hyatt, '97, p. 220). As there is doubtless in most

shells an increasing amount of space unoccupied by the soft por-

tion of the animal as it increases in age, it is not necessary to

postulate a great shrinkage of the soft tissues to account for the

thickening of the shell. Yet the fact remains that in many species

the principal thickening is over the main trunks of the vascular

sinuses, just where the genitalia occur in modern species and

where very probably they were located in fossil ones.

'The greater reduction of the lateral growth of the mantle over

that of anterior growth in brachiopods is seen in the fact that in

old age the shell is proportionally longer than in maturity. The

result of these old-age processes appears first at the cardinal angles

where the loss of lateral growth to compensate for the shrinkage,

causes the flattening-out of the mantle folds (see also Williams,

'95, p. 309). The reduction of the radial ribs proceeds progres-

sively from the cardinal angles to the anterior border of the shell

and hence it is on the sinus and fold that we find the ribs persist-

ing strongest.

In those cases where the ribs flatten out entirely their continu-

ance is indicated by zigzag lines of growth on the smooth surface

of the gerontic portion of the shell. These show that the mantle,

after flattening out on one plane, still retained the scalloped border

on another. This scalloped edge (as seen for example in Rhyn-

chotrema capax) resulted from the faster growing of parts of the

mantle over others. As the mantle curved, the parts which formed

the summits of the ribs fell behind those which formed the depres-

sions. In other words the portions in the depressions grew faster.

'This difference in the rate of growth may be seen by following

two ribs and their included sinus from the umbo to the front of

118 THE AMERICAN NATURALIST [Vor. XL

the shell, plotting the angles and lengths of the successive growth

lines in crossing them (Fig. 30). Thus when the shell surface

becomes smooth in old age the zigzag lines of growth where pres-

ent represent the successive positions of the mantle border. It

is as if the plications had been merely transferred from the vertical

a b to the horizontal plane, as the actual

mantle is probably scalloped to the

v same degree in both cases and the

absence of ribs results simply from the

3 changed angle of curvature of the shell.

Often, hovever, there is a tendency of

the mantle edge to fill out the scallops

and to present a smooth edge. A

beginning in this direction can be seen

at the cardinal angles of many plicate

individuals. Examplesof this are noted

in very old specimens of Spirifer oweni,

Fic. 30.— Diagrams showing the

slower growth of the plications

when compared with the furrow

between. a, enlargement of a

furrow and its bounding plica-

tions with a few concentric

growth lines; b, the growth lines

ically the greater growth in the

furrow; p, plication; s, sinus

or furrow; c, concentric growth

lines. These figures were plot-

ted from the median sinus of a

specimen of Rhynchoterma

capaz, No. 142, Harvard. x 24.

Rhynchotrema capaz, etc.

The continued anterior growth after

the practical cessation of lateral growth

causes the cardinal angles to increase

in size and causes also the shell index

to decrease (see sections 6 and 7).

This is a taking-on again of the large

cardinal angles and small index of the

nepionic stage.

Not only is there repetition of youth-

ful characters in the outline of the shell

but there is also a similar repetition in the loss of ornamentation,

for the nepionic shell is smooth. An old man with his bald head,

curved back, toothless gums, and size smaller than during matu-

rity, resembles the child. Though in these and in many other

respects the resemblance is very striking yet in the child the form

is the result of positive, developing factors; in the man it is nega-

tive, degradational (see also Hyatt, '97, p. 218). So among

brachiopods the enlargement of the cardinal angles, reduction

of shell index, and the obliteration of ribs, spines, nodes, etc., are

in a certain sense a return to the features seen in the nepionic

No. 470] OLD AGE IN BRACHIOPODA 119

stage, yet it is a resemblance due to loss of characters. It is thus

essentially different from the developing of the similar characters

in youth. The characters usually disappear from the shell in the

inverse order of their initiation (see also Hyatt, ’94, p. 20, and

Beecher, :01, p. 269).

As seen above, senility is first shown at the cardinal angles

and from there it takes place progressively to the anterior portion

of the shell. Hence it is at the cardinal angles that we look for

the first expression of old age,— as a change in the angle of cur-

vature, lamellose growth lines, flattening of ribs, and development

of a groove at the junction of the valves. Very rarely are indi-

viduals found sufficiently old to have expressed on the anterior

portion of the shell all of the above senile characters.

When these characters do not appear simultaneously on the

shell they appear in a definite order, viz., (1) flattening of ribs,

(2) lamellose development of concentric growth lines, (3) change

in the angle of curvature, (4) formation of a groove at the junc-

tion of the valves, (5) flattening of sinus and fold. ‘This is the

usual order, though at the cardinal angles they frequently occur

at approximately the same growth line.

Originating thus at the cardinal angles, these gerontic features

are pushed farther and farther forward until in paragerontism

they are present on the most anterior portion of the shell.

MASSACHUSETTS Institute OF TECHNOLOGY

GEOLOGICAL DEPARTMENT

120 THE AMERICAN NATURALIST [Vor. XL

LITERATURE

BEECHER, C. E.

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State Mus., vol. 1, no. 1, pp. 1-95, pls. 1-8.

Cumines, E. R.

:03. The Morphogenisis of Platystrophia. A Study of the Evolution

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Davipsow, T.

'86-'88. A Monograph of Recent Brachiopoda. Trans. Linn. Soc.

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GRABAU, A. W.

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HALL, J., AND CLARKE, J. M

’92. An Introduction to the Study of the Brachiopoda. [Part I.]

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Haut, J., AND CLARKE, J. M.

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943, pls. 23-54.

FERN J., AND CLARKE, J. M.

Geological Survey of the State of New York. Paleontology.

Volume 8. An Introduction to the Study of the Genera of

Paleozoie Brachiopoda. Part 2.. Albany, xvi + 394 pp., pls.

21-84.

Hancock, A.

'59. On the Organization of the Brachiopoda. Phil. Trans. Roy.

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Hvxrey, T. H.

'56. Contributions to the Anatomy of the Brachiopoda. Proc. Roy.

Soc. London, vol. 7, pp. 106-117, 2 figs

Hyarr, A.

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Hyatt, A

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xi+238 pp., pls. 1-14, tables.

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Hyatt, A.

bre Phylogeny of an Acquired Characteristic. Proc. Amer. Phil.

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HYATT, A. à

'96. Lost Characteristics. Amer. Nat., vol. 30, pp. 9-17.

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Jackson, R. T.

'90. Phylogeny of the Pelecypoda. The Aviculidz and their Allies

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text figs. 1-53

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:04. Natural History of some Common Animals. Cambridge Biol.

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Observations on Living Brachiopoda. Mem. Boston Soc. Nat.

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Raymonp, P.

: The reiten Fauna at Canandaigua Lake, New York.

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'97. A Synopsis of American Fossil Brachiopoda including Bibli-

ography and Synonymy. Bull. U. S. Geol. Surv., no. 87, 464 pp.

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:04. Upper Silurie and Lower Devonic Faunas of Trilobite age

Orange County, New York. N. Y. State Mus., Rep.

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:02 Hamilton Group of Thedford, Ontario. Bull. Geol. Soc. Amer.,

vol. 13, Dr 149-186.

Wrams, H.

"95. Geli Biology.

ZrrTEL, K. A.

:00. iban of Paleontology. Transl. and ed. by C. R. Eastman.

THE HABITS OF NECTURUS MACULOSUS!

ALBERT C. EYCLESHYMER |

Necrurvs although widely distributed throughout eastern and

middle North America, is found most abundantly in the rivers

tributary to the Great Lakes and in the inland streams and small '

lakes of the adjoining States. Upon the study of the lake species

(Necturus maculosus Rafinesque) the following notes are based.

The many names under which Necturus has been described

lead to such confusion that some of those most frequently met

are here given: Necturus maculatus, Necturus maculosus, N ecturus

lateralis, Menobranchus | lateralis, Menobranchus tetradactylus,

Menobranchus sayi, Menobranchus lacepedii, Menobranchus hye-

malis, Phanerobranchus tetradactylus, Phanerobranchus lacepedit,

Triton lateralis, Proteus maculatus, Siredon hyemalis, Siren lacer-

tina. It is known by fishermen and others unacquainted with

scientific nomenclature by various names such as: Proteus of

the Lakes, Proteus of the Alleghany River, Siren of Barton,

mud-puppy, water-dog, water-lizard, fish-lizard, etc.

Size.— According to the writer’s observations the adults vary

considerably. in size, ranging from twelve to eighteen inches.

This is based upon an extended series of measurements of indi-

viduals taken from different localities and comprising not only

the females taken from their nests in the spring, but also both

males and females taken in the autumn. It is thus evident that

the writer cannot agree with David Starr Jordan (799, p. 175)

and other eminent systematists that Necturus attains a length

of 24 inches. In order to ascertain upon what observations these

1 Rafinesque, in 1818, described this form under the name Sirena maculosa

(Amer. Monthly Mag. and Crit. Review, vol. 4, 1818, p. 41). In 1819, the

name Necturus maculatus was given (Journ. de Physique, vol. 88, 1819, p.

418). In 1820 the specific name maculosus was restored (Annals of Nature

or Annual Synopsis of new Genera and Species of Animals, Plants. . . .discovered

in North Amèrica. First Annual Number, 1820. Transylvania University,

March 1, 1820. Lexington, Ky.).

123

124 THE AMERICAN NATURALIST (Vor. XL

statements are based, the literature has been carefully searched.

If we turn to the earliest description, given by Schneider (1799,

p- 50) we read: “Corpus ultra 8 pollices longum.” This

measurement was given for the specimen which he found in

Hellwig’s cabinet at Braunschweig and which Hellwig had ob-

tained from Lake Champlain. The specimen described by

Lacépède (’07, p. 230) was obtained by M. Rodrigues and placed

* in the Natural History Museum but its original source was un-

known. The specimen measured 15 cm.

Mitchell (21) in 1821 received a specimen from Major Dela-

field taken from Lake St. Clair. In a descriptive letter written

to Professor Configliacchi of Pavia we read the following: “He

grows, as I am informed, frequently to the length of two feet.

The present specimen is not more than one half that length, one

of the smaller having been selected for the greater ease of trans-

portation.” |

A length of two feet is here mentioned for the first time, and

as Harlan (’35, p. 164) has already pointed out, this mistake was

due to the fact that Necturus and Cryptobranchus were confused

by Mitchell. In a letter written to Charles de Schreiber in 1823

Mitchell (’21) even speaks of Necturus as the creature “ which

the white fishermen have called by the vulgar name of Hell-bender

and the Indians 'T'weeg." It is not difficult to understand how

such an error might have occurred since certain naturalists (Daudin

Lacépéde, Barton) had considered Necturus as the larval form of

Cryptobranchus.

Even Cuvier (29) writes: “L’espece la plus connue (Meno-

branchus) vit dans les lacs de l'America septena et devient

fort grande; atteint dit on, deux et trois pieds." Since this time

the error has been repeatedly copied.

Coloration.— The color of the adult is so variable that a descrip-

tion does little more than emphasize this fact; indeed the writer

has been so forcibly impressed with this variability that it has

led to the surmise that Necturus possesses the ability, more or

less common to other Amphibia, of changing its color through

its control of the black chromatophores. The animal usually

appears a dark ashy brown above, with more or less irregular

mottling; below it is more evenly colored and of an ashy flesh

No. 470] HABITS OF NECTURUS 125

tint. The mottling is due to the presence of large irregular dark

areas which are surrounded by a pale yellow margin. Often

these spots coalesce to form larger areas or bands. In the younger

animals there is frequently a dark band extending from the nostril

to the eye, from the eye to the anterior margin of the gills, and

from the posterior margin of the gills backward along the side

of the body. In some cases the upper surface presents no large

areas but is more uniform, and the chromatophores and lipo-

chromes are so distributed that the surface presents a granular

appearance. The ventral surface of the body frequently becomes

lighter toward the median line and in some a sharply defined

linea alba is present. The lower part of the head and tail are

frequently dotted with small clusters of lipochromes.

In short, the contrast of black and yellow may in some appear

vivid, in others subdued and again disappear almost entirely.

It is probable that these variations in color are responsible for

a number of specific names. As ‘an instance I might state that

some years ago Dr. Garnier ('88) described a small Necturus,

taken from the Maitland and Lucknow Rivers in Ontario, to

which he gave the name Menobranchus lateralis, var. latastei.

“The colouration above was black, the abdomen sooty and the

gular fold white.”

. During the summer of 1904 the writer was fortunate enough

to secure two young animals which measured about 4 and 6 inches

respectively. The smaller corresponds closely to the description

given by Dr. Garnier and there is every reason for believing that

the animal in question is the young of Necturus maculosus. The

older of the two presents the general coloration of the adult. That

Necturus should undergo such striking changes in color may

appear remarkable to one who has not studied the early stages

but when one has followed the changes in color patterns during

growth he finds that they are no less striking and remarkable

than in the birds.

Habitat.—'The environment to which they are best adapted

is not known. In spring and summer excepting the time of egg-

laying they are most frequently observed in quiet waters from

four to eight feet deep where a clean sandy bottom is fairly well

covered by vegetation. In the autumn they are found in pairs

126 THE AMERICAN NATURALIST [Von XL

or small groups. From this fact and others to be recorded later

it is inferred that this is the mating season. —

At times they seem to congregate in large numbers. Milner

(74, p. 62) states that “Mr. George Clark of Ecorse, Mich., had

a minnow-seine fitted to the bag of a sweep-net, and at one haul

took two thousand of the ‘water-lizards.’ Estimating the extent

that the net had passed over, he calculated the average number

of ‘lizards,’ to each square rod, to be four." Milner again states

that “a fisherman at Evanston, Ill., a few years ago had nine

hundred hooks set in the lake, and in one day took from these

five hundred lizards.” p x |

Holbrook says that “they are seldom taken except in the months

of April and May.” Kneeland states that “they are rarely if

ever seen except during the winter.” The writer has repeatedly

taken them through the ice on set lines during the months of

January and February. Reese also reports having taken them

through the ice in February. While there are no records showing

that they are taken i in all the winter months there is but little

doubt that they are more or less active throughout the winter,

a fact which indicates the absence of a period of hibernation.

Necturus moves from place to place at night and rests quietly

beneath boards, logs, or stones during the day. In aquaria they

avoid the sunlight, and retire if possible to a shaded portion and

always seek concealment. Their movement in the water is slow

and is effected by walking, in which act the diagonally opposite

legs move in unison. When disturbed they move with celerity

through a vigorous lateral motion of the broad and powerful tail,

with: the feet closely applied to the body and motionless. "They

never swim long distances, at most a few yards, then seek con-

cealment either in the mud or beneath some object.

One is rarely fortunate enough to get a glimpse of them during

the day; they seem to be extremely sensitive and disappear at

the slightest disturbance of the water, such as that caused by

the approach of a boat. If they are undisturbed, one usually

sees the head protruding from beneath the concealing object.

The animal thus presents a curious appearance with its ruby

gills moving gracefully to and fro. When they are disturbed

the gills change from their bright red to a dusky color and are

at once drawn down tightly against the neck.

No. 470] HABITS OF NECTURUS 127

When these animals are retained in aquaria they are frequently

observed to thrust their snouts above the water, open the mouth

widely, and then return to the bottom where they soon expel the

air both through the gill slits and from the mouth. It would

thus seem that while the branchiz are the chief means of respira-

tion the lungs play considerable part. Kneeland (59) made some

very interesting observations on this point which are here quoted.

“He put two of these repüles into an aquarium with half a dozen

minnows, varying in size from two to three inches. 'The fish

were frequently seen nibbling at the expanded gills of the rep-

tiles, which as often suddenly darted from their ordinary state of

repose, attempting to seize the fish, which they never succeeded in

doing. In about ten days the menobranchs had nothing left of

the gills but the almost bare cartilaginous supports, with only

here and there a branchial fringe. The fish were then taken

out, and the branchial fringes began to grow again, and in the

course of six months had regained about half their normal size.

He had watched these reptiles for two summers, and no similar

falling of the gills ever took place, so that it appears in the pres-

ent instance that the fish actually eat them off, their loss being a

pathological and not a natural phenomenon. In either case this fact

seems interesting from a physiological point of view, as bearing

upon the respiratory organs of these reptiles. He had ascertained

experimentally that they survive out of water about four hours,

showing that their pulmonary sacs, or lungs, are not alone suf-

ficient for the maintenance of respiration. In the present in-

stance, though their pulmonary sacs were the principal respira-

tory organs, the animals did not apparently suffer. .

“The question , arises, why are these lungs áppsieltly sufficient

for respiration in the water and not in the air, though the respired

element be in both cases the same? As there is no evidence of

internal gills, the reason must be that in the air the branchial

tufts from dryness are unfit for circulating the blood, the com-

plimentary respiration of the skin, so important in reptiles, can-

not be carried on — the pulmonary sacs alone are insufficient

for the aération of the blood, and the animal dies. In the water,

however, even though the branchie, as in this case be useless,

the cutaneous respiration is unimpeded and with the pulmonary

128 THE AMERICAN NATURALIST [Vor. XL

is sufficient for the purification of the blood. This fact shows

the importance of the cutaneous respiration and the insufficiency

of the pulmonary."

Food.— Concerning their natural food little is known beyond

the fact that dissections of the alimentary tract reveal the presence

of small crustaceans, insect larvee, and occasionally a small fish.

Harlan (35) and James (723) both record having found earth-

worms in the alimentary tract. Kneeland (58) says: “They

seize living worms eagerly and suck them down, if small, with

a single sudden swallow; if the worm be large, it is swallowed

by repeated suctions, the teeth preventing its escape; the act

of suction may be seen by the movements of the impurities in

the water, as it is drawn in and afterwards expelled. They often

miss the worm; sometimes it may be too far off, but at others

so close to them that it seems that their vision must be imperfect.

They will not eat a dead worm unless they have been kept with-

out food for a considerable time."

A very curious performance was witnessed by Kneeland and

reported by the secretary of the Boston Society of Natural His-

tory as follows: “A number of Necturi had been without food

for five months when four living minnows were placed in the

aquarium, three of the four minnows were swallowed before

the expiration of fifteen minutes, and among them the largest.

After they had swallowed them, they seemed very uneasy, moving

the bones of the head and jaws, and contorting their bodies in

various ways, as if they did not feel quite easy in their stomachs;

however they at last became quiet, but at the end of twenty hours

they became uncommonly active, and the three fish were regurgi-

tated with the scales off, the eyes out, and the entrails of the

smallest gone; they were perfectly white, and looked like ghosts

of fish. It was either diet to gross for their delicate and weak-

ened stomachs, or else not sufficiently comminuted for the action

of their gastric juice." Garnier says that they eat small living

fish and crayfish by preference, and do not readily take meat

in captivity. |

Montgomery states that “from observations of the Meno-

branchus in an aquarium plentifully stocked with molluscs, such

as Physide, Limnzans, Paludin®, Planorbes, Anodonts, etc., as

No. 470] HABITS OF NECTURUS 129

well as crustaceans I am not warranted in asserting that it feeds

on anything other than true fishes."

Milner quotes Clark as stating that “those taken at Ecorse,

Mich., were so gorged with white-fish spawn that when they were

thrown on shore, hundreds of eggs would fly out of their mouths."

'The writer has tried to feed them with various kinds of food.

Necturus will readily eat living earthworms but will pay no atten-

tion to dead ones. Pieces of liver which are held in forceps and

moved gently through the water in close proximity to the snout they

seize and devour. But the most satisfactory food is small minnows

which at intervals are placed in the aquaria. The movements

of the minnows seem to excite the animals whose heads are soon

seen protruding from beneath the concealing objects. When

the minnow comes in close proximity there is a flash-like move-

ment toward the minnow which in turn either escapes or is swal-

lowed. 'The writer has observed repeated failures to catch the

minnow, but the persistence of the animal is remarkable and

it sooner or later succeeds. ,

From the fact that whenever the water is disturbed in the vicin-

ity of the snout they snap viciously one is led to infer that in taking

food they rely almost entirely upon the tactile sense.

Necturus is much dreaded by the ordinary fishermen who re-

gard them as poisonous as do also the Indians (Durkee). Ac-

cording to Gibbes (753) the negroes are terrified by its presence.

He says that "the piggin or wooden vessel, in which an animal

was placed after its capture, was destroyed by the negro to whom

it belonged, who was resolved never to carry food in it or eat out

of it again." Notwithstanding this popular superstition the ani-

mal is perfectly harmless and may be handled at pleasure. Its

flesh is white and said to be very palatable by Wilder (74) who

writes as follows: “In preparing a paper upon their anatomy

and embryology, Dr. W. S. Barnard and myself have had occa-

sion to use them in numbers; and a single fisherman, who sets

many hooks for fish has brought us a hundred during the past

month (March); he, and all others, apparently regard them as

poisonous, and are rather averse to touching them; so far is this

from the case, that they are absolutely harmless in every way:

and on the 5th Dr. Barnard and myself ate one which was cooked,

130 THE AMERICAN NATURALIST [Vor. XL

and found it excellent: it is our intention to recommend it as

food, but not until our investigations are complete.”

Their great tenacity of life is a matter of frequent comment.

They seem to be able to live for months without food. ‘They

have been left for three or four hours out of water and are then

easily revived. After severe mutilations they recover, but not-

withstanding this great vitality they seem to fall easy vietims of

a fungus which has not as yet been determined specifically. Mr.

Browne (Milner, ’74) of Grand Haven, Michigan, states that

“some years ago, an epidemic seemed to prevail among the Meno-

branchi in Grand River, in the month of June, and that their

carcasses were washed ashore by hundreds, so that they lined

the banks of the river and the mill-men were obliged to throw

the bodies off into the current, to be carried down stream to pre-

vent the offensive eem that was wafted into the mills from the

decaying remains.’

Casting of Epidermis. — Kneeland (’57) states that Necturus

sheds its epidermis in the winter. ‘They shed their skins at

this season; I have had several with the old skin hanging to the

new in shreds and patches, which are washed off by the water

in two or three days, leaving the colors of the new skin very

bright; the edges of the tail are then so thin and transparent

kd the network of blood vessels can be seen with thé naked

eye.’

While endeavoring to obtain a photograph of Necturus on

February 9, 1897, Mr. A. H. Cole, one of my students, observed

the animal cast its epidermis. His notes read as follows: “The

epidermis as a thin layer appeared to have loosened from the

entire surface of the body, appearing frosty-white with bubbles

of air. The loosened epidermis was split along the mid-dorsal

line, its free edges floating upward in ragged streamers. On the

following day none of the epidermis remained excepting glove-

like portions which were yet attached to the feet; these portions

were not cast until two days later.”

Breeding Habits.— Although more than a century has elapsed

since Necturus became an object of special study on the part of

both American and European naturalists, no one seemed fortu-

nate enough to obtain embryological material until Professor

No. 470] HABITS OF NECTURUS 131

Charles O. Whitman some eighteen years ago discovered the

nests and obtained a complete series of developmental stages.

Those who sought the embryological material were forced to

enter an unexplored field. No one felt certain that he had even

found the adult animal, since the error of Mitchell, that the adult

measured two feet, had been and is yet, copied by the leading

systematists. Moreover, Barton (Gray, ’57, p. 61) held that the

animal was the larval form of Cryptobranchus. Cope (66) ex-

pressed the opinion that it was a larval Sperlerpes and changed

in the same manner as the Siredon to an Amblystoma. Baird

(50) suggested that it might be the unmetamorphosed form of

some great salamander as yet unknown. If the above were true

it then remained to be determined whether the animal bred in

the larval or the adult condition, or in both. All these possibil-

ities demanded careful consideration.

Again it was not known whether they were purely aquatic or

whether they came frequently on land, as described by Smith

(32), DeKay (42), and others. When this question was an-

swered others arose, and foremost among these was the time of

breeding. Concerning this period there were numerous con-

jectures. Kneeland (757) states that the animals were taken in

abundance near the shore during the winter months. “ The

reason why they approach the shore at this season may be on

account of this change in skin, and possibly for breeding purposes.

About once a week they pass from the anus a gelatinous mass,

about the size of a pea, of a whitish color, I thought this might

be possibly an egg, but the envelope soon becomes soft in water,

and its contents are lengthened out into a somewhat convoluted

form.”

Holbrook (’42) observes that er are "seldom taken except

in the months of April and May which is their spawning season.

Their eggs are about the size of peas and as many as one hundred

and fifty have been counted in a single female.”

Milner (’74) states that a “full series was this season (73) col-

lected from the Detroit River, from the length of one and one

fourth inches to thirteen inches. Later, about the middle of the

month of July, Mr. George Clark collected a quantity of their

eggs, proving this month to be the spawning season of the animal.”

132 THE AMERICAN NATURALIST [Vor. XL

Spring, summer, and winter were each regarded as the breed-

ing season and, so far as the observations were concerned, with

equal degrees of probability.

Thus there was little to be gathered from the observations pre-

viously made. ‘The only reliable data were to be obtained through

a systematic examination of the ovarian eggs at different seasons

of the year. Even when this tedious work had been carried out

and clews obtained as to the egg-laying period, other and greater

difficulties arose. The Great Lakes and their tributary streams

in which Necturus had been reported most abundant were usually

so clouded by muddy water that search for eggs was futile. Local-

ities must be found where the animals were plentiful and where

the water remained clear. The small inland lakes of eastern

Wisconsin seemed best to fulfil these conditions. Again, no one

knew or had even suggested where the animals deposited their

eggs, whether in deep or shallow water, whether they were laid

in masses in open places like those of Amblystoma, or scattered

in strings like those of the toad, or laid singly and concealed among

the leaves and branches of aquatic plants like those of the newt.

The knowledge of the egg-laying habits of other Amphibia

gave no clue, but nevertheless the work was continued and after

years of persistent and patient effort Professor Whitman finally

discovered the nests and eggs of Necturus. Only those who have

for years been baffled in their attempts to obtain the embryological

material of other North American Urodeles, such as the Siren,

Amphiuma, and Cryptobranchus can properly appreciate the

enormity of the task.

Through the kindness of Professor Whitman the writer first

obtained a knowledge of the habits and breeding places of Nec-

turus, and each summer for the past eight years has made obser-

vations on the habits of these animals in their natural environment.

Egg-laying.— The time of egg-laying varies in different lakes,

depending upon the time when the temperature of the water reaches

a certain degree. In the larger, deeper lakes with bold shores

this is much later than in those possessing wide shoals. Again,

in the individual lakes the time is dependent upon the same con-

ditions. The eggs are first deposited in those localities where

the water is shallow and exposed for the greater part of the day

No. 470] HABITS OF NECTURUS 133

to the sun. The period of egg-laying usually covers two or three

weeks. There is no foundation whatever for the statement made

by Hans Virchow! that the animals deposit their eggs so to speak

at the same hour.

According to Professor Whitman’s and my own experience the

best time for collecting is during the middle and latter parts of

the month of May. The writer has collected eggs as early as

May 3, and as late as June 5, but these extremes mark the begin-

ning and closing of the early and late seasons.

Preparatory to egg-laying, Necturus seeks the sandy shoals of

the lakes or streams. ‘They seem to prefer those localities where

the bottom is strewn with numerous logs and boards. It is more

than probable that the animals seek these grounds at night since

they are rarely if ever seen moving about during the day.

During the day they lie quietly concealed beneath the various

objects and one not familiar with their habits would rarely if ever

detect their presence. If one desires to see the animals in their

natural positions he must approach with much care and he may

perchance be rewarded by seeing the head of one protruding. If,

however, the jar of the boat or the scraping of an oar has caused

them to hide, he must overturn the concealing object. If this

is done with great care the animal is occasionally undisturbed

and lies for some time motionless, then begins to crawl slowly :

about. If, however, the disturbance be violent it darts away

and conceals itself beneath some other object.

The nest of Necturus, if indeed, such it may be called, is, as

has been said, always carefully concealed beneath some object

and consists of nothing more than a slight excavation in the sand

with a narrow opening through which the animal’s head pro-

trudes; the nest is thus perfectly guarded against the attacks of

enemies. The objects beneath which the nests are most frequently

found are clean logs or boards which lie partially imbedded in

1 Sitzb. Ges. natur]. Freunde zu Berlin, 1894, p. 37: * Necturus kommt

in den zalreichen Seeen im südlichen Wisconsin häufig vor und auch an

anderen Stellen der Vereinigten Staaten. Die Laichzeit ist nach mündlichen

Angaben der Brüder Meyer Mitte Mai, im Jahre 1893 fiel sie auf den 22. Mai,

d. h. später wie gewöhnlich; sie variirt nach dem Wasserstande. Die Thiere

legen nicht zu verschiedenen Zeiten ab, sondern angeblich zu gjeicher Zeit,

sozusagen auf dieselbe Stunde."

134 THE AMERICAN NATURALIST [Vor. XL

the sand. The writer has also found them beneath pieces of

tin, canvas, and even an old hat.

The depth of the water in which these nests are found, is vari-

able. The writer has found nests covered by only four inches of

water, again a nest was found beneath a board at a depth öf ten

feet, but these are unusual conditions. ‘The majority of nests are

found at a depth of from two to four feet. The nests are often

found in close proximity to one another; and it is not at all excep-

tional to find several nests on a single board frequently not more

than a foot or two apart. In one instance ten nests were taken `

from a single board not more than twelve feet long.

In order to facilitate the collection of eggs it has been found ad-

vantageous to place boards in suitable localities during the early

spring months. When the breeding time has come many of these

shelters will have been chosen as nesting places.

During egg-laying the males are never found with the females,

and where they remain is unknown. In just what manner the

female deposits the eggs is also problematic. There are’ different

stories told by those who during recent years have acquired some

knowledge of their habits. In some way the female brings her

body in such a position that the eggs are deposited on the shelter-

ing object. When the laying is finished the eggs are found scat-

tered over a surface from six to twelve inches in diameter. The

eggs are attached singly by the outermost of the three enclosing

envelopes and are about a quarter of an inch in diameter, of a

pale cream-color, sometimes showing a faint tinge of green.

The period of deposition undoubtedly covers many hours and

probably i in some instances, days, since in several cases all the

eggs were removed from nests and the following day freshly de-

posited eggs were found. Further proof is found in that the same

nests frequently contain eggs in both early and late cleavage stages.

This supposition is further confirmed by the fact that some days

after the beginning of egg-laying the oviducts yet contain mature

eggs.

If one wishes to leave the nest in such a condition that the fe-

male will return and continue laying he must exercise great care

in replacing the object to which the eggs are attached. If the

nest be much disturbed, one will find upon his return for a fresh

No. 470] HABITS OF NECTURUS - 135

supply of eggs, that even those which were left are missing. Sev-

eral times the writer has found an animal in the nest whose stom-

ach was distended with eggs. The inference, although positive

proof is wanting, is that the parent devours her eggs when the

nest is much disturbed.

The length of time which intervenes between ee and

the beginning of cleavage has been accurately determined in a

single instance in which four eggs were deposited after the animal

was placed in the aquarium. ‘These were placed in a hatching

dish in which the water was 17° C. In one egg the first cleavage

groove appeared in 18 hours, in two at 20 hours, and in one at

23 hours. The time in some cases certainly exceeds 24 hours,

since eggs taken from the nest were kept in a hatching dish for

this length of time before cleavage began.

LITERATURE

Bamp, n

Revision of North American Tailed Batrachia, with Descriptions

of New Genera and x Journ. Acad. Nat. Sci. Phila, ser.

2, vol. 1, pp. 281-2

Corr, E. D.

'66. On the Structures and Distribution of the Genera of the Arci-

ferous Anura. Journ. Acad. Nat. Sci. Phila., ser. 2, vol. 6, pp.

67-112, pl. 25. i

Cuvier, G.

'29. Le regne animale. Paris, new ed., vol. 2:

DeKar, J.

'42. Natural History of New York. Part 3. Albany.

GARNIER, J.

':88. [On a New Species of Menobranchus Makirallr var. lataste) ]

Proc. Can. Inst., ser. 3, vol. 5, pp. 218-219.

Gisges, L. R.

'53. Description (with Figure) of Menobranchus punctatus. Boston

Journ. Nat. Hist., vol. 6, pp. 369-373, pl. 13.

136 THE AMERICAN NATURALIST [Vor. XL

Gray, J. E.

’57. On the Genus Necturus or Menobranchus, with an account of its

Skull and Teeth. Proc. Zool. Soc. London, vol. 25, pp. 61-64.

Haran, R.

'85. Medical and Physical Researches or Original Memoirs. Phila-

delphia.

Hor»roox, J. E.

'42. North American Herpetology; a Description of the Reptiles

inhabiting the United States. Philadelphia, 4to, 5 vols., illus.

JAMES, E.

'23. Account of an Expedition from Pittsburg to the Rocky Moun-

tains, 1819-20. London, 3 vols.

Jordan, D. S.

'99. Manual of Vertebrates of the Northern United States. Chicago,

8th ed.

KNEELAND, S.

’57. [On a supposed New Species of Siredon.] Proc. Boston Soc. Nat.

Hist., vol. 6, pp. 152-154.

KNEELAND, S.

'58. [Habits of Menobranchus.] Proc. Boston Soc. Nat. Hist., vol. 6,

pp. 371-373.

KNEELAND, S.

’59. [On the Breathing Apparatus of the Menobranchus.] Proc.

Boston Soc. Nat. Hist., vol. 6, pp. 428-430.

LacÉpEpzg, B. G.

'07. Sur une espèce de quadrupède ovipare non encore décrite. Ann.

8. Hist. Nat. Paris, vol. 10, pp. 230-233, 1 pl.

MILNER, J. ; w.

"4. Report on the Fisheries of the Great Lakes: the Result of In-

quiries prosecuted in 1871 and 1872. Report U. S. Fish Comm.,

1872-73, pp. 1-75.

MıtcHELL, S.L.

'21. Observations on Several Reptiles of North America, which seem

to belong to the Family of Proteus, etc. Amer. Journ. Arts

and Sci., vol. 7, pp. 63-69.

SCHNEIDER, J. G.

1799. Historiæ Amphibiorum Natrii et Litterariæ. Jena.

SMITH,

32. [N ecturus coming out on Land.] /sis, p. 1088.

QEBDG

"14. Mesibeitidus Edible. Amer. Nat., vol. 8, p. 438.

NOTES AND LITERATURE.

ZOOLOGY.

Kellogg's American Insects.'— It is gratifying to observe the great

progress that is being made in the science of entomology, and to

welcome a book such as the author now brings before the public.

While the biological side is strongly emphasized it is not overdone

and we have the subject presented in a much broader sense than

has perhaps ever been done in a single volume. It is written in a

clear and popular style, and the fact that the species of economic

importance are more fully treated adds much towards making the

work of general interest. The 674 pages are illustrated by over

800 figures in the text and 18 colored plates, well selected to show

the biologic, systematic, and economic features in the study of insect

life.

The first chapter treats of the structure and special physiology of

insects, and the second of the development and metamorphosis,

followed by the classification and description of the various groups '

arranged under 19 orders, with keys to the families and many of the

genera.

The student will naturally compare this work with that concise

and well balanced volume, Comstock’s Manual,— a work dearer to

the hearts of American entomologists to-day than a year or two after

its publication. While the new work is quite different i in its general

makeup, and of a more popular nature, it has not been edited with

as much care, but, considering the size of the volume there are com-

paratively few mistakes, and those which might be misleading to the

young student can be briefly noted as follows: on page 201 the figure

of Ranatra jusca represents either an imperfect specimen, without

wings, or an immature example; the respiratory tube is also poorly

shown; Fig. 317 is a Micromus not Hemerobius; Coptocycla auri-

chalcea, Fig. 389, and Cassida bicolor mentioned in the text (page

281) are synonymous (the latter specific name is now used); Fig.

* Kellogg, Vernon L. American Insects. New York, Henry Holt and

Co., 1905. Svo, vii-- 674 pp., 13 pi 812 text figs. $5.00.

137

138 THE AMERICAN NATURALIST [Vor. XL

463 is Dasyllis sacrator; Fig. 500 is Sepedon fuscipennis not fasci-

pennis; Plate 12, Fig. 3, is Synchloé reakirtit not genutia; Plate 13,

Fig. 3 is an Elis sp.; Figs. 681 and 682 undoubtedly represent the

same species. Although questioned, it is hard to account for Fig.

684, which belongs to an entirely different family; the male of Pele-

cinus polyturator is figured in Packard's Guide to the Study o] Insects.

Following the chapters devoted to the descriptions of the various

orders is a very interesting chapter on insects and flowers in which

the pollination of various plants by insects is described. A chapter

on "Color and Pattern and their Uses" presents a subject open to

much criticism. There is a tendency to carry the so called “mimicry,”

or preferably protective resemblance, beyond the limits of our every-

ay walks in the fields and woods, 7. e., to emphasize this feature by

selecting the most pronounced forms Bois the fauna of the world and

arranging them in museums regardless of their natural surroundings.

The **dead-leaf butterfly" (Kallima) is very effective arranged on a

twig among the dried leaves of the elm or beech, but when we read

that the butterfly usually alights on the trunk of the tree head down-

ward, the charm is broken. Our various species of Polygonia (Grapta)

and several groups of moths present fully as interesting examples of

protective resemblance. A very instructive and timely chapter is

devoted to insects and disease. The work concludes with an appen-

dix on collecting and rearing insects.

C. W. ds

Kingsley's Elements of Comparative Zoology.'— In this second

edition of Kingsleys Elements of Comparative Zoölogy the most

marked changes from the first edition (1897) are due to a re-

arrangement, the descriptive part being separated from the labora-

tory directions and brought together to form the last two thirds of

the book, under the heading, in the table of contents, of “Systematic

Zoölogy.” This plan, which is that adopted by the same author

in his Comparative Zoölogy of Vertebrates, would seem to be of

distinct pedagogical value owing to the confusion in the student’s

mind arising from the discontinuity of the other arrangement. The

questions for a tabular comparison of the forms studied and the groups

‘to which they belong — an especially valuable feature — have been

retained, and in a few cases somewhat extended. On page 108 there

is a repetition of er (3 and 7) which should be corrected.

'Kingsley, J. B Elements of Comparative Zoölogy. Second edition, revised.

New York, Henry Holt and Co., 1904. 8vo,x + 437 pp.

No. 470] NOTES AND LITERATURE 139

Punnett's Mendelism.'— A useful popular exposition of Mendel's

law of heredity. It contains a brief biographical sketch of Gregor

Mendel, an account of his experiments in hybridizing plants, the

rediscovery of his law of heredity long after Mendel’s death, with

numerous examples of Mendelian inheritance in animals as well

as in plants. No complete account is given of the development of

Mendelian theory since 1900, nor does the book contain a bibliog-

raphy.

W. E. C.

Hantzsch's Birds of Iceland.’— This substantial contribution

to faunal ornithology is a good example of the present-day “local

list,” or résumé of the avifauna of a circumscribed area. Iceland,

because of its position and physical features, affords an unusually

interesting field for study. The grass-lands, the moors, the barren

mountain tops, the glaciers, rivers, woods, and sea here provide a

variety of country, but the rigorous environment is unsuited to many

land birds.

The author in his introduction, summarizes briefly the ornitho-

logical literature of Iceland, and at the end of the chapter lists the

more important works dealing with Icelandic birds. The topography

of the island is then treated and the species peculiar to the different

areas are listed. An interesting feature is the hot springs which

never freeze in the winter and make it possible for certain species

to pass the cold season in their vicinity far to the north of their usual

winter range. ! `

A number of changes in the avifauna within historic times are

noted. Certain birds of prey have evidently decreased, as have also

certain fresh-water ducks. Eider ducks, owing to recent protective

legislation are more abundant now than formerly. ‘The cliff-breed-

ing Alcidz are for the most part holding their own. The Great Auk

was exterminated in Iceland in 1844. Following chapters deal with

the derivation of the birds of the region, their migrations, and their

economic importance to the Icelandic people. The migrations are

of particular interest and might well have been treated in more detail.

A number of wanderers reach Iceland during the fall migrations,

‘Punnett, R. C. Mendelism. Macmillan and Co., London, 1905. 16mo,

vii + 63 pp.

®Hantzsch, Bernhard. Beitrag zur Kenntnis der Vogelwelt Islands. Berlin,

R. Friedländerand Sohn, 1905. vo, vi + 341 pp., 26 figs., 1 map. 12 Marks,

140 THE AMERICAN NATURALIST [Vor. XL

having evidently been blown out to sea by southerly storms in crossing

from Norway to the lands to the south. Migrants to the far north

and Greenland pass through on their migrations, or come down in

fall to winter, for the warm Gulf Stream waters keep the southern

coast of Iceland largely open in the cold months. The fall migration

of native birds is chiefly to the southeast, via the Faróe Islands to

the British Isles or to southern Norway, and the reverse in spring.

'The second part of the book is devoted to the annotated list of

Icelandic birds, with synonymy, and notes on the habits. One

hundred and twenty species are recorded as certainly known, exclu-

sive of the Great Auk. 'The greater part of these are water birds,

and some thirty-two only are land birds, of which latter, but twelve

are known to breed in Iceland. In the notes relative to the different

species is brought together a great mass of valuable information

largely the result of the author's personal experience. A few of the

more interesting notes are the account of the nesting of Megalestris

skua; the occurrence of a single specimen of the Yellow-nosed Alba-

tros (Thalassogeron chlororhynchus) for several seasons on the south

coast until shot (in 1846); the nesting habits of Barrow's Golden-

eye Duck; and the occurrence of such American species as the Amer-

ican Widgeon, Belted Kingfisher, the Lapland Longspur (rarely

noted with flocks of Snow Buntings).

The author's use of Latin names differs somewhat from the accepted

usage of American ornithologists. Thus the Kittiwake is Rissa

rissa; Palidna is used as an emendation of Pelidna. We are glad

to note, however, that the Ringed Murre is not considered a distinct

species from Uria troile.

G.M. A

Holder’s Half Hours with the Lower Animals.'— Dr. Holder, to

use his own rather awkward phraseology, has “endeavored to make

this volume a popular combined review and supplemental reader on

the lower forms of animal life from the Ameeba to the insects

inclusive." There are twenty-nine chapters, twelve of which are

devoted to the different families of insects, four to crustaceans, and

one each to most of the other groups. It seems to the present

reviewer a mistake to have attempted the combination of text-book

and reader. The result is neither fish, flesh, nor fowl. There is

‘Holder, Charles F. Half Hours with the Lower Animals. Protozoans,

Sponges, Corals, Shells, Insects and Crustaceans. New York, American Book

Company, 1905. 8vo, 236 pp., illus.

No. 470] NOTES AND LITERATURE 141

a great deal of information about the more interesting species, en-

livened by bits of personal observation on the Florida reefs and off

the California coast. Every now and then the author remembers

that the book was also intended for a text-book, and injects accounts

of the external or internal anatomy of the group or species under

discussion with references to accompanying figures. ‘There is con-

stant evidence either of careless throwing together of notes or of a

very poor literary handling of material. On page 81 the reader

has been hearing about Lingula for nearly two pages, when suddenly

in the very midst of a paragraph he takes a flying leap into a Sikh

rebellion in India and is put to flight by a horde of land leeches which

drop from the trees. On page 213, the author, speaking of butter-

flies, refers to a figure of the head of a moth; moreover the figure

shows the pollinia of an orchid attached to the moth’s eyes, and the

reader is allowed to assume that they are a structural part of the

head.

The book has decided merit as a reference book or a supplementary

reader for a class in nature study. If the author had not coquetted

with the text-book idea, and had arranged his material with more

care, the book could have been greatly improved. The illustrations

are excellent.

R H.

Notes.— Additional Records jor New England Crusiacea. Since the

publication of Miss Rathbun’s list of the New England Crustacea

(Occasional Papers Boston Soc. Nat. Hist., vol. 7, no. 5, July, 1905)

the writer has gone over the study series of the Society’s collection

and the more recent acquisitions. During this work notes were made

when the specimens found added something to the records published

in that list, either in the way of localities, extension of range, or the

animals with which the crustacean was associated either as a i pane

site or in a symbiotic relation. These records follow :—

Uca minax (LeConte).— Above Fall River, on the Taunton River,

were found all three species of Uca; on sandy flats on the outer river

bank were found U. pugnax (Smith) common, and U. pugilator

(Bose.) a few. In Thatch Pond, a somewhat protected area, were

found U. pugnax, a few, and U. minax (LeConte) very plentifully.

Sesarma reticulatum (Say).— A single specimen of a male from

Bristol, R. I., and several specimens from Wood’s Hole, Mass.

Pinnotheres maculatus Say.— Specimens from gills of Modiolus

modiolus Linné, Vineyard Sound.

142 THE AMERICAN NATURALIST [Vor. XL

Pagurus pollicaris Say.— A single specimen from Beverly Bridge,

Mass., collected by J. H. Emerton, gives a northward extension to

the range of this species.

Cirolana polita (Stimpson).— Specimens from Ipswich, Mass.

JEga psora (Linné).— Single specimens from Head Harbor, Me.,

Matinicus Island, Me., and off Thatcher's Island, Mass.

Nerocila munda Harger.— Specimens from fins of file fish, Buzzards

Bay, Mass. !

C hiridotea ceca (Say).— Eastport, Me.

Asellus communis Say.— Salem (J. S. Kingsley, coll.) and Boston,

Mass. (S. Henshaw, coll.).

Tryphosa pinguis (Boeck).— Eastport, Me., (A. S. Packard, coll.).

Ampelisca macrocephala Lilljeborg.— Specimens from Grand Ma-

nan give a more northern record. ‘There are also specimens from

No Man's Land, Mass. (A. Hyatt, coll.).

Ampelisca compressa Holmes.— Also from No Man's Land, Mass.

Byblis gaimardii (Kröyer).— Eastport, Me.

Haploóps robusta G.'O. Sars.— Massachusetts (H. D. Storer, coll.).

Acanthazone cuspidata (Lepechin).— Eastport, Me., and off Cape

Ann, Mass., 25 fathoms.

Lafystius sturionis Króyer.— Cape Ann, Mass., on cod.

Pontogeneia inermis (Króyer).— Eastport, Me.

Dexamine thea Boeck.— Beverly Harbor, Mass., (J. H. Emerton,

coll.). : $

Gammarus annulatus Smith.— Noank, Conn.

Mera dane (Stimpson).— Eastport, Me., and off Cape Ann, Mass.

Ischyrocercus anguipes Króyer.— Eastport, Me., and Marblehead

Neck, Mass., (J. H. Emerton coll.).

Ericthonius rubricornis (Stimpson).— Eastport, Me., and off Cape

Ann, Mass.

Dulichia porrecta (Bate).— Eastport, Me.

gina longicornis spinossima Stimpson.— Salem, Mass.

Caprella linearis (Linné).— Annisquam, Mass.

Lepas anserifera Linné.— Portland, Me., from vessel.

Lepas jascicularis Ellis and Solander.— Eastport and Pemaquid,

Me., Ipswich Bay and Lynn, Mass.

Lernea branchialis Linné.— Annisquam, Mass.

Eubranchipus vernalis (Verrill).— Cohasset, Mass.

; : | JosePH A, CUSHMAN.

No. 470] NOTES AND LITERATURE 143

BOTANY.

Smith's Bacteria in Relation to Plant Diseases.'— Bacteriol-

ogists have long awaited Dr. Smith’s work on the bacterial diseases

of plants. We are now favored with the first part dealing with the

methods of work and general literature of the subject. The mono-

graph is not intended to take the place of the many text-books on the

‚subject, but rather to supplement them. The work will be found

useful to animal pathologists, as well as to plant pathologists. The

monograph is the outgrowth of the work which has ‘been carried on

in the study of bacterial diseases of plants in the Laboratory of Plant

Pathology, United States Department of Agriculture. The methods

described have all been tested and are now in use in the Department.

The following suggestions in regard to “A Study of an Organism”

should be impressed on every beginner. :

“Every one who has carefully inquired into the matter knows

that the brief statement of the behaviour of an organism on nutrient

agar, on gelatin, and on two or three other media, with perhaps a

loose statement of its color and size, no longer constitutes a description

which describes. Such accounts, of which there are a great many,

usually fail to mention just those things which might serve to dis-

tinguish the organism from its fellows. If a new species is not to be

described so that it can be identified by others, what then is the use

of any name or description? The name will only serve to encumber

future synonymy and to recall the incapacity of its author.” -The

following opies indicate the broad and comprehensive scope of the

subject matter: The Disease, The Organism, Physiology, Relation

to Free Oxygen, Luminosity, Bibliography, General Literature, and

Formule. | vc

'The author states that great stress should be laid on the minute

morphology in a variety of cultures. He: recommends especially

the use of photography in microscopie work, which Dr. Koch has

said “would certainly have prevented a great number of unripe pub-

‘Smith, Erwin F. Bacteria in Relation to Plant Diseases — Volume 1,

Methods oj Work and General Literature oj Bacteriology exclusive of. Plant

Diseases. Publication No. 27 Carnegie Institution of Washington, 285 pp.,

31 pls., 146 text figs. : : ; iu

144 THE AMERICAN NATURALIST [Vor. XL

lications.” Not only is it necessary to determine motility, but the

organs of motility should be stained. The part of the work dealing

with culture media is an excellent treatise; every working bacteriol-

ogist can get many valuable suggestions from it. The many con-

flicting statements as to the behavior of organisms by different authors

arise largely from the character of the media used. In regard to

vegetable media, he prefers to have them sterilized in the steamer rather

than the autoclave. If boiling changes the nature of any fluids it

is advisable to use the Chamberland or Berkefeld filter, but Chamber-

land bougies should not be used continuously for more than three

days, because of the growth of small organisms in the walls of the

filter, when they should be sterilized. There is a highly interesting

discussion of sensitiveness to plant acids. The Bacillus tracheiphilus

is used to show tolerance for sodium hydrate. Its tolerance for

this substance can be considerably increased by inoculating each

time from alkaline bouillons rather than from acid ones. ‘The

thermal relations of bacteria are among the most interesting and

should be studied with great care. Under the head of economic

aspects of the subject he argues with force that more attention

should be given to the collection of accurate statistics by competent

rsons as an aid to legislature and governments. There are some

excellent suggestions on natural methods of infection, how the para-

sites are introduced from one field to another by the roots of plants

and in plants. The soil is a living thing and should not be trans-

ported from one field to another carelessly; the parasite may gain

an entrance through wounds, by way of the stomata, lenticels, water

pores, and nectaries. The keeping of records is an important part

of the work of the experimenter, and it would be well for every

bacteriologist to have Dr. Smith’s work at hand and follow care-

fully the outlines given. The beginner should also be interested in

the card-catalogue system used by the author.

e systematist will be interested in his discussion of nomenclature

and classification, a subject naturally in a very chaotic state because

systematic botanists have given so little attention to it, and medical

men have cared even less about the classification of bacteria. He

does not think it advisable to use Bacillus 1, 2, or 3 or A. B. C.; if

the organism is really new and distinct, it should be given a name.

Every working botanist will agree with him that all polynomials

like Bacillus coli-communis are to be regarded as “nomina excludenda.”

We agree also that all species antedating the Koch poured-plate

method, which are not accurately described, should be abandoned.

No. 470] NOTES AND LITERATURE 145

“The Micrococcus pellucidus, although published quite recently

and in the Comptes Rendus of the French Academy, is not described

any better.” “I find it quite impossible,” says Mr. Stoddert, “to

identify many species from published descriptions.” Numerous

complaints of this sort, made in recent years by well trained and com-

petent men, sufficiently indicate the necessity of a thoroughgoing

reform. He makes a plea for better and more careful descriptions,

and concerning the use of the uncertain old names says: “And

here I wish to register a protest against anything of this nature ever

being done. If, in his own generation, a name cannot be associated

beyond doubt with a particular organism by means of an author's

description or figures or collected specimens, then this name should

disappear, never to be revived. Societies of bacteriologists should

unite in the near future on some authoritative date for the beginning

of species priority, so that some sort of stability may be guaranteed

to the nomenclature of the future.” :

In this part of the work there is a good discussion of the more

modern systems of classification, that of Dr. Alfred Fischer, 1895,

and the Migula classification, the latter of which is largely followed

in this country. He then gives descriptions of the following orders

and families: order Eubacteria, family Coccacee (Zopf emend.),

Mig., family Bacteriacese, family Chlamydobacteriaceze; order Thio-

bacteria, family Beggiatoacez, family Rhodobacteriacex, subfamily

Thiocapsacex, subfamily Lamprocystacex, subfamily Thiopediacez,

subfamily Amoebobacteriacez, subfamily Chromatiacez, to which

he has very properly added the Myxobacteriacee. Some changes

are proposed in nomenclature of genera and species. The genus

Bacterium (Cohn) takes.the place of Pseudomonas of Migula. 'The

seudomonas campestris becomes Bacterium campestris. ‘The Bacillus

anthracis of Cohn is the type of a new genus, Aphlanobacter. The

organism then should be called Aphlanobacter anthracis (Cohn) E. F.

Smith. The genus Vibrio (Muller, Cohn) includes the Spirillum

cholera-asiatice. Otherwise he follows the classification of Migula.

There are good grounds for the changes here proposed.

The author has brought together formule for stains, synthetic

and nonsynthetie culture media, tests for indol, and fixing fluids.

Sixty-three pages are devoted to: bibliography, well: arranged and

frequently provided with abstracts of the papers. Many excellent

plates accompany the paper. The frontispiece contains halftones

of five eminent bacteriologists: Ferdinand Cohn, Robert Koch,

Louis Pasteur, Emile Roux, and Emile Duclaux.

146 THE AMERICAN NATURALIST [Vor. XL

This volume is the most important piece of general bacteriological

literature that has been published in this country. It would be wel

indeed to have a copy of it in every working laboratory.

LB Pattie

A Bibliographical Index of North American Fungi.'— For

about thirty years Professor Farlow has been accumulating a card

index referring to the fungi of North America. Nearly twenty years

since, two authors’ lists of works on this subject were published, and

have been kept at the elbow of every student of our fungi since their

appearance. ‘The publication has now been commenced of the

references to genera and species, as Publication No. 8 of the Carnegie

Institution.

The preparation of an index may appear to the uninitiated a simple

matter. A perusal of the author’s seven-page preface is calculated

to undeceive one who holds such an opinion, and the preface also

contains some of the most sensible of recent commentary on nomen-

clature in natural history. A full list of abbreviations, and their

consistent use, have rendered possible a wonderfully condensed pres-

entation of the references to publications, which are kept within the

limits of a single text line each. Synonyms are intelligibly collo-

cated with accepted names, and free use is made of cross references.

In the preparation of the index, the author has had the assistance

of Mr. Seymour's keen eyes for many years, and it may be predicted

with safety that no important omissions will be found. Dr. Farlow’s

own familiarity with the literature of his subjeet is second to that of

no one, and the knowledge of fungi that he has brought to the accept-

ance of admitted names, the placing of those treated as synonyms,

and a very free critical annotation, is unequalled.

The Carnegie Institution is to be congratulated on having under-

taken the publication of so generally useful a work as the Index of

North American Fungi, the value of which in facilitating thorough-

ness of study is certain to make itself felt in all future publications

on this important subject.

W.T.

Osterhout’s Experiments with Plants ’— This book brings before

‘Farlow, W. G. Bibliographical Endes of North American Fungi. Vol. 1,

part 1, “ Abrothallus" to “ Badhamia.” The Carnegie Institution, Washington,

Sept. 1,1905. 8vo, xxxv + 312 p.

2Osterhout, W. J. V. Experiments with Plants. New York, The Maemillan

Company, 1905. 8vo,x + 492 pp., 252 figs.

No. 470] NOTES AND LITERATURE 147

the teacher and student the latest phase in the development of mor-

phological conceptions. No longer is the plant treated as a mere

mechanical complex of root, stem, and leaves. Instead it is pre-

sented as a living being, plastic in its environment. The work of

root, stem and leaves, of the flowers and of the fruit, the influence

of the surroundings upon the plant, are discussed in separate chapters,

and these matters are made the subjects of extensive experimental

investigation. Yet these experiments are simple in the extreme, as

` is the apparatus, in the construction of which a great deal of ingenuity

has been displayed. It is such that any handy, intelligent boy can

readily make it. i

'The primary-school teacher will find this book a valuable adjunct

in her work; in the high school and university it can be given directly

into the hands of the student, whom it forces to think rather than be

content with the absorption of predigested statements.

The last two chapters, the one on plants which cause decay, fer-

mentation, and disease and the other on making new kinds of plants,

bring the laboratory more directly in touch with the outer world since

they show how man can control diseases on the one hand and the

formation of new varieties of fruits and flowers on the other. The

introduction of a chapter relating chiefly to the work of Burbank and

de Vries, with both of whom Dr. Osterhout is thoroughly acquainted

personally, is a distinct innovation as far as botanical text-books are

concerned. Then, too, the book deals with those other problems,

which more recently have been suggested to the popular mind by

newspaper and magazine articles, such problems as the pasteurizing

of milk, vaccination and antitoxins, the self-purification of rivers and

streams, nitrifying bacteria,— all of them issues of to-day and of great

popular interest, interest which will necessarily extend to Experiments

with Plants. — ]

'The book will prove equally acceptable from a purely botanical

and from a purely pedagogical standpoint. It is intended to take the

place of a similar book the writing of which was projected by Pro-

fessor Bailey, to complete his series of Botanical 'Text-books. Cer-

tainly no one was better qualified to undertake the work than Dr.

Osterhout, whose clear and concise manner of presenting the subject

and whose easy, almost colloquial style make the book attractive.

'The illustrations are as numerous as they are excellent. Most of

them are from original photographs and drawings, a very pleasing

feature, since it becomes tiresome to meet again and again the same

familiar drawings, however excellent. The bookwork too, deserves

148 THE AMERICAN NATURALIST [Vor. XL

commendation.. A fairly large type, good paper, and lack of typo-

graphical errors are always appreciated. ; | Er

Hus

Sargent's Manual.'— No other person so well equipped for the

description of North American trees as Professor Sargent could have

been found, nor an illustrator so expert and practiced as Mr. Faxon;

hence it results that no manual of our trees so good as the present

could have been expected from any other source. 'To the makeup

of the book the Riverside Press have brought their usual skill. The

total result, therefore, is a well devised, well written, well illustrated,

and well made book, condensing into convenient size what is neces-

sary for the study of our trees, and yet not skimping the descriptions.

As was to be expected, the sequence (after Engler and Prantl) and

nomenclature (after Sargent's Silva) are rather radically modern,

while the treatment of species is rather conservative except in the

daily amplifying genus Crategus, to which further species are here

added. ...,

A synopsis of families with a key based on their leaves renders the

first placing of a given form easy, while genera and species are differ-

entiated in the same manner. |

If any fault is to be found with the book it will probably be with the

absence of synonymy, especially that referring to the new names intro-

duced, except for references to differing names employed in the author's

Silva.

WR.

Notes.— Contributions from the Gray Herbarium of Harvard

University, n. s., no. 31, published as vol. 41, no. 9, of Proceedings of

the American Academy of Arts and Sciences under date of July 24,

contains “Descriptions of Spermatophytes from the Southwestern

United States, Mexico, and Central America,’ by Greenman, and

“Diagnoses and Notes relating to American Eupatoris,” by Robin-

son.

A reprint of the original edition of Nuittall’s Journal of Travels

into the Arkansas Territory, during the Year 1819, Philadelphia, 1821,

forms vol. 13 of Thwaites’ Early Western Travels, in course of publi-

"Sargent, C. S. Manual of the Trees of North America exclusive of Mexico.

Boston and New York, Houghton, Mifflin and Co., 1905. 8vo, xxiii + 826 pp.,

644 text figs., with map showing the principaltree regions of the United States.

No. 470] NOTES AND LITERATURE 149

cation by the Arthur H. Clark Company of Cleveland. The editor’s

preface to the present volume contains an interesting sketch of Nuttall’s

work.

The 3-volume edition of James’ Account of an Expedition from

Pittsburgh to the Rocky Mountains, performed in the Years 1819, 1820

. under the command of Maj. S. H. Long, London, 1823, forms

volumes 14-17 inclusive of Thwaites’ Early Western Travels.

The third series of Vegetationsbilder, by Karsten and Schenck

(Jena, Fischer, 1905) presents, thus far, “Flower Gardens of Brazilian

Ants,” by Ule, “Vegetation of Russian Turkestan,” by: E. A. . Bessey,

and the “Vegetation of Java,” by Biisgen, Jensen, and Busse.

Professor Peck’s “Report of the State Botanist, 1904” forms Bul-

letin 94 (Botany 8) of the New York State Museum, and bears date

July, 1905.

Coste’s Flore descriptive et illustrée de la France reaches Orchidacex

in the recently issued fourth fascicle of vol. 3.

Vol. 4, part 3, of Wood’s N atal Plants, issued in June, contains

plates 351-375, with descriptive text.

A revised classification of roses, by Baker, is published in the

Journal of the Linnean Society — Botany, of July 1.

Miss Eastwood has published a very usable handbook of the trees

of California under date of July 8 as Occasional Papers no. 9 of the

California Academy of Sciences. Leaf, fruit, and general character

keys make the paper useful, and it is illustrated by 57 plates, partly

from nature but largely after drawings by the late Dr. Kellogg.

A revision of Berberis is being published by Schneider in the Bul-

letin de l' Herbier Boissier.

The species of Cratzgus of Berks Co., Pa., are considered by C. L.

Gruber, of Kutztown, Pa., in three pamphlets, the first two of which

were issued by the Berks County Natural Science Club in 1903, while

the last appears in the Bulletin of the Torrey Botanical Club for 1905.

L. A. Dode has recently issued from vol. 18 of the Mémoires de la

Société d Histoire Naturelle d'Autun a monographie account of Pop-

ulus. © | a

A note on his American dbeertuions on the biennis group of Œno-

thera is separately printed by DeVries from the Album der Natuur.

150 THE AMERICAN NATURALIST [Vor. XL

Beccari’s long-interrupted palm studies have been resumed, and

he has recently published several important papers in Webbia, issued

by Count Martelli of Florence.

Habit re of Sabal palmetto are given by TEE in Die

Gartenwelt of July 15

A note on some ER at Le Martola is published by

Berger in The Gardeners’ Chronicle of August 26.

From tests recorded in Bulletin no. 72. Bureau of Plant Industry,

U. 8. Department of Agriculture, Scofield concludes that the salt water

limit of Zizania aquatica is approximately represented by 0.03 of the

normal solution of sodium chloride,— when the water is not appre-

ciably salty to the taste.

An illustrated paper on the ancestors of the “ Big Trees” (Sequoia),

by Berry, appears in Popular Science Monthly for September.

According to vol. 5, no. 3, of the Bulletin du Jardin Impériale Bota-

nique de St. Pétersbourg, the St. Petersburg garden has recently secured

three specimens of Osmunda regalis over 1000 years old.

Two fascicles (222 and 223) of Engler and Prantl’s Die natürlichen

Pflanzenjamilien, by ee dealing with: mosses, have recently

been issued.

A lecture on diatoms with illustrations, by Mann, is contained in

vol. 48, part 1, of Smithsonian Miscellaneous Collections.

Regeneration among kelps is considered by Setchell in wk 2, no. 5,

of University of California Publications — Botany.

A well illustrated popular account of desert plants is ns by

Holder in The Country Calendar of August.

A paper on the megaspore membrane of the gymnosperms, by

Thomson, forms no. 4 of the U mais of Toronto Studies, Biolog- -

ical Series.

Karyokinetie papers of importance occupy vol. 24, part 1, of the

Jahrbücher jur wissenschajtliche Botanik, issued in July.

The importance of investigations of seedling stages, as presented

by Dr. Harris before the St. Louis cdm of 1904, is a. in

Science of BT 11;

No. 470] NOTES AND LITERATURE 151

A paper on seed studies made by Todaro at the Modena agricul-

tural station is published in Le Stazioni Sperimentali Agrarie Italiane,

vol. 38, fascicle 5-6, with a colored plate showing the tests of dry and

viable seeds of Trifolium and Hedysarum.

A paper on the dispersal of seeds by wind is Po 7 Ridley in

the Annals of Botany for July.

The pollination of Cypripedium spectabile by honey-bees is de-

scribed and photographically illustrated by W. H. Sargent in Country

Lije in America for September.

A paper on the insect galls of Indiana, by M. T. Cook, is published

in the 29th Annual Report of the Indiana Department of Geology and

Natural Resources.

A paper on “The Science of Plant Pathology” is 3g by

Stevens in Popular Science Monthly for September.

Hedgcock, in Science of July 28, reports some of the results of his

work with “ crown gall” of fruit trees, walnuts, etc.

Some vine diseases in Sonoma County, Cal., are discussed by Butler

in Bulletin no. 168 of the Agricultural Experiment Station of the Uni-

versity of California.

A report on plant diseases of the State, E Sheldon, forms Bulletin

no. 96 of the West Virginia Agricultural Experiment. Station, issued

on June 30.

A second Hemileia, on orchids, is described and figured by Massee

in The Gardeners’ C hronicle of August 19.

A paper on white rust of the lemon is published by Cavara and

Mollica in vol. 17 of the Atti della Accademia Gioenia di Catania.

Three new fungi from Catalina Island are described by Ellis and

Everhart in the April Bulletin of the Southern California Academy of

Sciences, which also contains a short article by Blanche Trask on San

Jacinto plants.

Nigrospheeria is the name given by Gardner to a new genus pro-

posed for Spheria (Hypocrea) setchellii Harkness, in vol. 2, no. 6, of

University of California Publications — Botany.

Thaxter publishes ‘‘Preliminary Diagnoses of New Species of

Laboulbeniacez — VI” as Contributions from the Cryptogamie Lab-

152 THE AMERICAN NATURALIST [Vor. XL

oratory of Harvard University — LXII, in vol. 41, no. 11, of Proceed-

ings of the American Academy of Arts and Sciences, issued in July.

Mangin and Viala give an account of Stearophora radicicola, a fun-

gus parasite of the roots of Vitis, in the Revue de Viticulture of July 6.

Holway has begun the publication of a series of descriptions with

photomicrographic illustrations of the North American Uredines.

The first fascicle, dealing with the Puccinias of Ranunculacex, Ber-

beridacez, Papaveracex, Bromeliacex, Commelinacex, Juncaces,

Liliacez, Amaryllidacez, Iridacex, and Orchidacex, was issued on

the 15th of April.

A paper by Peglian on the os. disease of alfalfa is pub-

lished in vol. 14, no. 12, of Attidella R. Accademia dei Lincei.

An illustrated account of the Ustilagines of Connecticut, by Clinton,

forms Bulletin no. 5 of the Geological and Natural History Survey ot

that State.

An illustrated article on Mushrooms and Toadstools” is published

by Arthur in The Country Calendar for September.

A well illustrated preliminary report on the Hymeniales of Con-

necticut, by White, forms Bulletin no. 3 of the er ag and Natural

History Survey of the State.

An illustrated account of new Citrus creations of the Department,

by Webber and Swingle, is separately printed from the Yearbook of the

United States Department of Agriculture for 1904.

The maple-sugar industry forms the subject of Bulletin no. 59 of the

Bureau of Forestry, United States Department of Agriculture, by Fox

and Hubbard.

A paper on red gum (Liquidambar), by Chittenden and Hatt, has

recently appeared as Bulletin no. 58 of the Bureau of Forestry, United

States Department of Agriculture.

De Vries describes some of Burbank’s methods in Popular Science

Monthly for August.

An account of Kola in Yoruba Land is given by Bernegau in Der

Tropenpflanzer for July.

Statistics concerning yerba maté (Ilex paraguayensis) are given in

Daily Consular Report No. 2247, of May 2.

No. 470] NOTES AND LITERATURE 153

An account of rubber cultivation in Hawaii is given by Smith in

Press Bulletin no. 13 of the Hawaii Agricultural Experiment Station,

dated July 20, 1905.

An article on gutta percha, with photograms of Palaquium, is pub-

lished by Murdoch in The Indian Forester of June.

An exhaustive account of the aboriginal use of wood in New York

is given by Beauchamp in Bulletin 89 (Archeology 11) of the New

York State Museum.

Preliminary accounts of the recent International Botanical Congress

at Vienna are given by Rendle in The Journal of Botany for July 1

and Britton in Science of August 18.

Under the title Webbia, Count Martelli has recently issued a volume

of botanical papers, by various writers, commemorative of the 50th

anniversary of the death of Barker-Webb.

An appreciative sketch of Delpino, by Ludwig, is published in

Naturwissenschaftliche Rundschau of August 10.

The Journals. — Botanical Gazette, July:— Smith, “Undescribed

Plants from Guatemala and other Central American Republies —

XXVII"; Snow, “ The Development of Root Hairs”; Frye and Blod-

gett, “A Contribution to the Life History of Apocynum androsemi-

jolium”; Nelson, “Contributions from the Rocky Mountain Her-

barium — VI"; Bfarnes], “The Vienna Congress"; and Florence

Lyon, “Another Seed-like Character of Selaginella.”

Botanical Gazette, August:— Moore, “Sporogenesis in Pallavi-

cinia"; McCallum, “Regeneration in Plants — I"; Dean, “On

Proteolytic Enzymes — II”; Schneider, “Contributions to the

Biology of Rhizobia — IV, Two Coast Rhizobia of Vancouver Island,

B. C."; Beal, “The Vitality of Seeds"; Rose and Painter, ‘Some

Mexican Species of Cracca, Parosela; and Meibomia”; Greenman,

“A New Krynitzkia."

The Bryologist, September:— Chamberlain, “Maryland Bryo-

phytes and Two Mosses from Virginia”; Williams, “Notes on Luzon

Mosses”; Holzinger, “Bryum fosteri”; Britton, “The Botanical

Congress at Vienna”; Sargent, ‘‘Lichenology for Beginners — HI

Fink, *What to Note in the Macroscopie Study of Lichens — II^;

Gilbert, “ The Advantage of Frequent Visits to Moss Localities.”

154 THE AMERICAN NATURALIST [Vou. XL

Bulletin of the Torrey Botanical Club, July:— Latham, “Stimula-

tion of Sterigmatocystis by Chloroform”; Murrill, “The Polypor-

ace: of North America—XI, a Synopsis of the Brown Pileate Species”;

House, “ Further Notes on the Orchids of Central New York”; Piper,

“The two Eastern Species of Melica” ; Gruber, ‘‘Crategus in Berks

County, Pennsylvania — IIT.”

Bulletin of the Torrey Botanical Club, August:— Cannon, “On the

Transpiration of Fouquieria splendens"; Martin, “Studies on the

Effect of some Concentrated Solutions on the Osmotie Activity of

Plants”; Schneider, “Chroolepus aureus a Lichen”; Piper, “Poa

gracillima Vasey and its Allies.”

A small quarterly of miscellaneous contents, has been started

by T. J. Fitzpatrick of Iowa City under the title The Iowa Natur-

alist.

Journal o Mycology, May:— Morgan, “A New Obetespluerin? ;

Lawrence, “Notes on the Erysiphaceze of Washington"; Ellis and

Bartholomew, ‘ ‘Two New Haplosporellas” ; Beardslee, us "The Rosy-

spored Agaries or Rhodospore”; Ricker, "Notes on Fungi — II,

with New Species from Various Localities"; Bates, "Rust Notes

for 1904"; Thom, “Some Suggestions from the Study of Dairy

d Kellerman, “Index to North American Mycology” ; Keller-

man, “Notes from Mycological Literature — XV.”

J vital of the New York Botanical Garden, August:— MacDougal,

“The Suwarro, or Tree Cactus."

Pittonia, part 28:— Greene, “Revision of Eschscholtzia”; TA

New Pe Genus [Petromecon]”; “A Study of Dendro-

mecon"; “Suggestions Regarding Sanguinaria.”

The Plant World, June: — Ramaley, “A Botanist’s amps to Java" ;

Spillman, “ Cactus as a Forage Plant."

The Plant World, July:— Reed, *A Brief History of Ecological

Work in Botany”; Blodgett, “ Fasciation in Field Peas.”

P roceedings of the Iowa Academy of Sciences for 1904:— Shimek,

“Botany in its Relation to Good Citizenship”; Fink, “Notes on

American Cladonias"; Fink, “Some Notes on Coral Iowa Alge”;

Macbride, “The Slims Moulds of New Mexico”; Gow, “An Ecologi-

cal Study of the Sabine and Neches Valleys, Texas” ; Fawcett, “ Varia-

tion in Ray Flowers of Anthemis cotula and ‘sche Composites” ;

Buchanan, “Notes on a Thermophilic Bacillus”; Pammel, “Notes

No. 470] NOTES AND LITERATURE 155

on the Flora, especially the Forest Flora, of the Bitter Root Moun-

tains”; Seaver, “An Annotated List of Iowa Discomycetes”; Rueda,

“The Biology of the Bacillus violaceus laurentius or Pseudomonas

rapa Anderson, “Plants New to the Flora of Decatur County,

Iowa”; Lindly, “Flowering Plants of Henry County"; Watt,

“Growth and Pigment Production of Pseudomonas janthina”;, Peck,

“ The Flowering Plants of Hardin County.”

Proceedings of the Society jor the Promotion of PRIME aao.

26:— Bailey, “What is Horticulture ?”; Lazenly, “The Economic

Uses of Wood”; Pammel, “Some Fungus Diseases Common in

Iowa During the Season of. 1904”; Beal, “The Vitality of Seeds”;

Arthur, “The Part taken by Deletes: and /Ecidia in the. Dis-

tribution of Maize and Cereal Rusts.”

Rhodora, August:— Shear, “Letter of Dr. Asa Gray to Lewis D.

de Schweinitz”; Blanchard, “The Yellow-fruited. Variety of the

Black Raspberry”; Fernald, “The Genus Arnica in Northeastern

America," “Spergula sativa in Connecticut,” “Some Lithological

Variations of Ribes," and “Anaphalis margaritacea var. occidentalis

in Eastern America” ; Ballard, “A Second Vt. Station for Arenaria

macrophylla.” XT |j

Torreya, July:— Schneider, *An Example of Complex Life-rela-

tionship"; Christ, " Quelques mots sur l'article de Mr. Underwood

‘A much Named Fern’”; Greene, “Derivation of the Name Chame-

crista"; Harper, “Two Misinterpreted Species of Xyris.”

Torre eya, August:— Coker, “Observations on the Flora of the

Isle of Palms, Charleston, S. C."; Cockerell, “Names of Insects”

Hanmer, “A Note regarding the Discharge of Spores of Pleurotus

ostreatus.”

GEOLO GY.

Notes.— Water Supply and Irrigation Papers, 97, 98, 99, and 100,

form the report of the branch of the Division of Hydrography dealing

with stream measurements for the year 1903. These four reports

represent over fifteen hundred pages of valuable data, collected from

almost all the important streams of the United States. The results

have been compiled by J. C. Hoyt, under the direction of F. H. Newell.

156 THE AMERICAN NATURALIST [Vor. XL

The relation between rainfall and run-off, under different climatie

conditions, is very clearly brought out in many of the tables.

The “Report of Progress of Stream Measurements for the Cal-

endar Year 1904” forms Water Supply and Irrigation Papers 124-

135 inclusive. The various portions of the country are treated in

the separate bulletins, as follows :—

124, Pt. 1, Atlantic Coast and New England Drainage.

125, “ 2, Hudson, Passaic, and Delaware River Drainages.

126, “ 3, Susquehanna, Patapsco, Potomac, James, Roanoke,

Cape Fear, and Yadkin River Drainages.

127, Pt. 4, Santee, Savannah, Ogeechee, and Altamana Rivers,

and Eastern Gulf of Mexico Drainage.

128, Pt. 5, Eastern Mississippi River Drainage.

129, “ 6, Great Lakes and St. Lawrence River Drainage.

130, “ 7, Hudson Bay, Minnesota, Wapsipinicon, Iowa, Des

Moines, and Missouri River Drainages.

131, Pt. 8, Platte, Kansas, Meramee, Arkansas, and Red River

Drainages. |

132, Pt. 9, Western Gulf of Mexico and Rio Grande Drainages.

133, “ 10, Colorado River and the Great Basin Drainages.

134, “ 11, The Great Basin and Pacific Ocean Drainage in Cali-

fornia.

135, Pt. 12, Columbia River and Puget Sound Drainages.

A new term applying to veins, namely “rift-veins,” is proposed

by J. A. Reid, in a paper entitled “The Structure and Genesis of

the Comstock Lode” (University of California, Bulletin of the Depart-

ment of Geology, vol. 4, no. 10, pp. 177-199). The type of this kind

of vein is the Comstock, where “the surface ‘east vein, the famous

bonanza, and the ‘vein’ now being worked have an identical origin.

Their formation lies in the fact that the lower part of the hanging

wall block has settled more than the upper, relative to the foot wall,

and has been torn apart by the stresses developed."

The Journal oj Geology for July-August, 1905, contains the fol-

lowing articles: “The Geographical Cycle in an Arid Climate," by

W. M. Davis; “Notes on Baked Clays and Natural Slags in Eastern

Wyoming," by E. S. Bastin; “The Delaware Limestone,” by C. 5.

Prosser; *M egacerops tyleri, a New Species of Titanothere from the

Bad Lands of South Dakota," by R. S. Lull; “Comment on the

"Report of the Special Committee on the Lake Superior Region, "

by A. C. Lane.

No. 470] NOTES AND LITERATURE 157

“The Lead, Zinc and Fluospar Deposits of Western Kentucky," by

E. O. Ulrich and W. S. T. Smith, forms Professional Paper no. 36 of

the United States Geological Survey. The general geology of the dis-

triet is treated by Ulrich, while the detailed description of the different

' deposits is by Smith. Smith regards the fluorite as having been

deposited from circulating underground waters, and having been

derived, probably, from the limestones of the region. On noticing

the number of faults and dikes that have been mapped in this region,

one questions why a deep-seated source of the fluorite is regarded

untenable.

The character of the triclinic feldspars at high temperatures has

recently been investigated by Messrs. Day and Allen. The careful

measurements of the melting points, points of crystallization, specific

gravities, etc., all prove that in triclinic feldspars, isomorphism is

complete. The slides prepared from the various feldspar mixtures

were examined by J. P. Iddings, and he found that, optically, the

feldspars correspond very closely to the mixtures prepared. The

optical portion of the paper is illustrated by six remarkably clear

plates. This report is entitled “The Isomorphism and Thermal

Properties of the Feldspars," and is published by the Carnegie Insti-

tution of Washington, as Publication no. 31.

An exhaustive description of the Bingham District of Utah has

been prepared by Boutwell Keith, and Emmons. This report,

which is published as Professional Paper no. 38 of the United States

Geological Survey, consists of four parts. ‘The first part is a general

presentation of the problem by Emmons. The second part is by

Keith, and treats the areal geology of the region. The third, and

by far the most important portion of the monograph, is by Boutwell.

The successive stages of oxydation are well shown by the fact that

in the surface zone free gold, some oxides, and carbonates were found;

on descending, a zone of carbonates occurred, with a little sulphide;

while, at a greater depth, the sulphides became more and more abun-

dant until the carbonate and oxide ores have given place almost

entirely to sulphides, of which the copper sulphide is most important,

economically. The fourth portion of the report is an appendix describ-

ing the fossils of the Bingham District, by Girty.

Professional Paper no. 34 of the United States Geological Survey,

“The Delavan Lobe of the Lake Michigan Glacier of the Wisconsin

Stage of Glaciation and Associated Phenomena," by W. C. Alden,

158 THE AMERICAN NATURALIST [Vor. XL

is a detailed study of southern Wisconsin and northern Illinois. "The

report is fully illustrated by maps, re the successive. stages

in the deglaciation of the district.

` Publication 101 of the Field Columbian Museum, entitled “The

Rodeo Meteorite” by O. C. Farrington, is a description of a medium

octahedrite with high phosphorus content, weighing about one hun-

dred pounds. Lbs mass was found in 1852, in the State of Durango,

Mexico.

A series of ee which aim to give some quantitative values

for the pressures exerted by growing crystals, has been performed

by G. F. Becker and A. L. Day. In these experiments, it has been

proved that crystals increase most rapidly on their under surfaces,

and thus lift the earlier formed portions. So energetic is this action

that a kilogram weight was raised several millimeters by an alum

crystal whose bearing surface was only a small fraction of a square

centimeter. The force, therefore, is believed to be of the same order

of magnitude as the resistance that crystals offer to crushing. "The

published account of these experiments appears in the Proceedings

of the thou a Academy of Sciences, vol. 7, pp. 283-288.

PSD

(No. 469 was issued January 20, 1906)

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ds A. ALLEN, Pu.D., American Museum of Natural History, > York

E. A. ANDREWS, Pr. D., Johns Hopkins University, Baltim

; WILLIAM S. BAYLEY, Pu.D., Colby University, Wa E

-DOUGLAS H. CAMPBELL, Pu.D., Stanford Unioeraiy

= J. H. COMSTOCK, S.B., Cornell University Ithaca

— WILLIAM M. DAVIS, M.E. Sites University, Cambridge

= ALES HRDLICKA, M.D., U. S. National Museu EN

—D. S. JORDAN, LL.D., Stanford University

= CHARLES A. KOFOID, Px.D., University of California, Berkeley

Ta NEEDHAM, Pn.D., Lake Forest University

ARNOLD E. ORTMANN, Pu.D., Carn ripis Museum, Pittsburg

EG nr Museum of m History,

a a is an inet monthly ag zine

. General Biology, Zoology,

ical Geography, and Mi

ach month will cor

ee sn ssi

pa S, s, biographic

en E to Shee there will vll be ‘briefer Wess

interest

editorial. deris on scientific questions of the

vs of recent ure pant: a Secs record of.

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THE

AMERICAN NATURALIST

Vor. XL March, 1906 No. 471

NOTES ON REPTILES AND BATRACHIANS

OF PENNSYLVANIA, NEW JERSEY

AND DELAWARE

WITMER STONE

IN view of the increasing interest in the study of our reptiles

and batrachians it seems desirable to place on record any facts

that may add to our knowledge of the distribution and relative

abundance of the various species. 'The writer therefore offers

the following list which is based upon his personal observations

in eastern Pennsylvania and southern New Jersey, and upon

specimens contained in the splendid collection of the Academy

of Natural Sciences of Philadelphia, which includes the collec-

tions of Green, Hallowell, A. E. Brown, and Cope, together with

local material collected by Samuel Ashmead, Samuel N. Rhoads,

Henry W. Fowler, and the writer.

No species are included unless specimens obtained in one of the

three States have been examined, and unless otherwise stated the

specimens are in the Academy collection.

It follows that a few species which have been recorded from the

district under consideration but of which no specimens were ac-

cessible have been omitted, and as the notes are only intended as

a contribution toward a complete list, no attempt has been made

to quote records or observations at second hand. Further collec-

tions will undoubtedly extend the range of many species.

Necturus maculosus Rafinesque.— One specimen obtained in

159

160 THE AMERICAN NATURALIST [Vor. XL

Darby Creek near Essington, Delaware Co., Pa., by Jas. Gardiner,

March 2, 1900, is the only example I have ever seen from this

vicinity.'

Cryptobranchus alleghaniensis (Daudin). —Mainly west of the

Alleghanies. Specimens examined from the Beaver and Alle-

ghany Rivers and also from the Susquehanna near T'ucquan, Lan-

caster Co., where it was occasionally taken by the late Jacob

Stauffer, of Lancaster, Pa.

Amblystoma opacum (Gravenhorst ).— I have never personally

collected this species but have examined specimens from

New Jersey, Atlantic City (W. J. Fox), Beesley's Point (Ash-

mead ), and Medford (J. S. Wills);

Delaware, Newark (T. B. Wilson ).

Amblystoma punctatum (Linné ).— Occasional but not an abun-

dant species.

Pennsylvania, Philadelphia (J. W. Tatum), Ardmore, Mont.

Co. (I. N. De Haven), Clifton, Delaware Co. (B. Wainwright ),

York Furnace, York Co. (Stone), Chambersburg (Rhoads ).

Amblystoma conspersum Cope.— Cope's type specimen from

Londongrove, Chester Co., Pa., is the only one I have seen from

this district.

Amblystoma bicolor (Hallowell).— I have seen only the type

specimen from Beesley's Point, N. J.

Amblystoma tigrinum (Green ).— Specimens have been exam-

ined from Beesley's Point, N. J. (S. Ashmead, G. H. Horn), and

from Crosswicks, N. J. (J. H. Slack). I have never taken it in

Pennsylvania.

Amblystoma jeffersonianum (Green ).— One specimen in the

Academy collection was obtained by Dr. Hallowell “ near Phila-

delphia." I know of no other captures.

Hemidactylium scutatum (Schlegel ).— Five specimens were ob-

tained by S. N. Rhoads at Swartzwood Lake, Sussex Co., N. 23

in October, 1895, and another from the same County a year later.

Plethodon cinereus (Green ).— An abundant species about Phil-

adelphia ranging to the highest parts of the Pennsylvania Alle-

ghanies, — Ganoga Lake, Sullivan Co. (S. Brown)—and to Swartz-

1 Cf. Fowler, Science, (n. 8.), vol. 11, p. 555, 1900.

No. 471] PENNSYLVANIA REPTILES AND BATRACHIANS 161

wood Lake, northern New Jersey (Rhoads). I have also taken

it in Delaware and have examined specimens from as far south as

Seaford in that State.

It has always been my experience that this and the following

species are nowhere equally abundant; one or the other always

predominates.

Plethodon glutinosus (Green ).— I have never taken this sal-

amander about Philadelphia or in southern New Jersey, and it

seems to be a characteristic species of the mountains or their foot-

hills.

I have examined specimens from the following localities: —

Pennsylvania, Warren Co. (Dr. Kennedy ), Venango Co. (Miss

Brown), Huntingdon Co. (Dr. Leidy), Juniata Co., York Co.,

Sullivan Co., Pike Co.

New Jersey, Swartzwood Lake, Sussex Co. (Rhoads).

Gyrinophilus porphyriticus (Green ).— This is also a mountain

species, and has never so far as I am aware, been taken within

the limits of the Carolinian fauna. I have examined the follow-

ing specimens : —

Pennsylvania, Warren Co. (Dr. Kennedy ), Altoona, Blair Co.

(Dr. Leidy ), Round Island, Clinton Co. (Rhoads ), and Tuscarora,

Juniata Co. (C. Ingersoll ).

Spelerpes bilineatus (Green ).— This is a rather common and

widely distributed species. I have taken it at various points in

Philadelphia, Chester, and Lancaster Co., Pa., as well as in south-

ern New Jersey west of the pine barrens. I have also examined

specimens from Atlantic City, N. J., and from Morris Co. (F.

Canfield), Swartzwood Lake and White Pond (Rhoads) in the

northern part of the State and from Dingman's Ferry, Pike Co.,

Pa. (Rhoads).

Spelerpes longicauda (Green ).— This species is not so plentiful

as the preceding and I have never taken it in the southeastern

part of Pennsylvania nor in southern New Jersey although there is

one in Cope’s collection from Atlantic City, N. J.

Farther west in Pennsylvania I have examined specimens from

Lancaster Co., Huntingdon Co. (Cope), Cresson, Blair Co., and

Round Island, Clinton Co. (Rhoads). In northern New Jersey

Rhoads obtained it at White Pond, Warren Co.

162 THE AMERICAN NATURALIST [Vor. XL

Spelerpes ruber (Daudin).--- A common species in spring heads.

I have taken it in Philadelphia, Chester, and Lancaster Cos., and

in Camden Co., N. J. It seems fairly well distributed and has

been obtained in the Alleghanies at Round Island, Clinton Co.

(Rhoads), and in Blair Co. (Dr. McCook); also at Wilmington,

Delaware. I fail to distinguish the variety montanus Cope.

Desmognathus ocrophea Cope.— This seems to be a boreal

species and I have only seen specimens from the higher Alle-

ghanies, Harvey’s Lake, Luzerne Co. (Stone), Lake Ganoga,

Sullivan Co. (Rhoads), and Clinton Co., Pa. (S. Brown).

Desmognathus fusca (Rafinesque).— Probably our most abun-

dant salamander. Found throughout eastern Pennsylvania,

northern and southwestern New Jersey, but apparently not in

the streams of the pine barrens. In Delaware it occurs in the

Brandywine drainage and probably elsewhere.

Desmognathus nigra (Green).— The only Pennsylvania speci-

men that I have seen is one presented to the Academy by Dr.

Holbrook without definite locality.

Diemyctylus viridescens Rafinesque.— An abundant species in

the lakes and ponds of the mountainous parts of Pennsylvania

and New Jersey; the terrestrial form is common in the hemlock

forests.

I have taken it sparingly in York and Chester Cos., but not

about Philadelphia nor in southern New Jersey, though Dr. Wilson

obtained some near Newark, Delaware.

Bufo lentiginosus americanus (Holbrook).— Everywhere abun-

dant from the mountains to the coast, including the pine barrens.

Acris gryllus crepitans Daird.— I have found this species com-

mon along the lower Delaware and Susquehanna valleys. H. W.

Fowler has secured it at Cape May, N. J., and S. N. Rhoads ob-

tained it in Sussex, Somerset, and Warren Cos., in the upper part

ofjthe State.

Chorophilus triseriatus Wied.— Personally I have not observed

this frog but Cope states that it is common in southwestern New

Jersey and he also observed it in southern Chester Co., Pa.

Rhoads obtained specimens at Pine Grove, Cumberland Co., Pa.

Hyla versicolor Le Conte.— This is the most frequent tree frog

during the summer, for the others are seldom seen except when

No. 471] PENNSYLVANIA REPTILES AND BATRACHIANS 163

gathered in the ponds, in springtime. It is quite generally dis-

tributed south of the mountains, the most northern specimen that

I have examined being from Morristown, N. J. (M. Fisher ).

Hyla pickeringii Holbrook.— A common species in shaded pools

in early spring. I have examined specimens from the Delaware

valley, Chester Co., Pa., and also from Altoona, Blair Co., Pa.

(Dr. Leidy), and Pine Grove, Cumberland Co. (Rhoads). Dr.

Wilson obtained it in Delaware.

Hyla andersonii Baird.— All the specimens so far secured ex-

cept the type have come from the pine barren region of New

Jersey. Dr. Leidy’s specimen from Jackson and one obtained

by Mr. H. L. Viereck! at Clementon are in the Academy’s collec-

tion. The others were two secured at Pleasant Mills by Dr. J. P.

Moore and one from May’s Landing, (J. E. Peters).

Rana pipiens Schreber.— Abundant all along the coast marshes

and large rivers. I have examined specimens also from White

Pond, N. J., and Waynesburg, Green Co., Pa. (Rhoads), and

from several cedar swamps in the New Jersey pine barrens. In

the latter region R. palustris does not seem to occur.

Rana palustris Le Conte.— Common throughout Pennsylvania

and in northern and southwestern New Jersey. It ranges to the

top of the Alleghanies as I have seen it in Sullivan and Wyoming

Cos., and Rhoads took it at Round Island, Clinton Co., Pa.

Rana sylvatica Le Conte.— Distributed throughout Penn-

sylvania and New Jersey. I have found it on the highest ranges

of the Alleghanies and on the edge of the pine barrens at Med-

ford, N. J., while Rhoads secured a specimen at May's Landing,

in the same State.

Rana clamitans Latreille.— Abundant and widely distributed,

occurring both in the mountains and in the pine barrens of New

Jersey where it is the most abundant frog.

Rana catesbiana Shaw.— Apparently widely disttibuted but

much scarcer than formerly. I have taken it on the lower Dela-

ware and Susquehanna and their tributaries and have seen speci-

mens from Absecon, N. J. (S. Ashmead ), and Harvey's Lake, Pa.

! Stone, Proc. Acad. Nat. Sci. Phila., 1901. Since this paper was prepared,

W. T. Davis has discovered this species and Rana virgatipes at Lakehurst

in the New Jersey pine barrens (Amer. Nat., vol. 38, p. 893; vol. 39, p.

795).

164 THE AMERICAN NATURALIST [Vor. XL

Rana virgatipes Cope.— All of the specimens of this interesting

frog that have been captured, are, so far as I am aware, in the

Academy’s collection and have been fully reported upon by H.

W. Fowler. They are all from the New Jersey pine barrens;

the one obtained by the writer was from Speedwell, Burlington

Co.

Carphophiops amenus (Say ).— Obtained in Chester and York

Cos., Pa., and Pt. Pleasant, Beesley’s Point (Ashmead ), Trenton

(Abbott), and Bridgeton (Walmsley ), N. J.

Virginia valerie Baird & Giraud.—One specimen is in the

Academy collection from Delaware received from C. Drexler.

Storeria occipitomaculata (Storer ).— A common snake through-

out the mountains south of the Pocono plateau and east of the

Alleghanies. I have only seen one example which I captured in

the New Jersey pine barrens on the edge of Bear Swamp, east of

Medford. This record is interesting as in the same vicinity we

find Evotomys, a northern rodent, common in the mountains, but

absent in the intervening territory.

Storeria dekayi (Holbrook).—A rather common snake in

southeastern Pennsylvania; also obtained at May’s Landing,

N. J., and doubtless of wider distribution in both States.

Clonophis kirtlandi (Kennicott).—' Two examples from the

region under consideration are in the Academy collection; one

obtained near Trenton, N. J., by Dr. C. C. Abbott, the other in

. Delaware Co., Pa., by E. Dutton.

Tropidoclonium lineatum Hallowell.— A snake was obtained

at Round Island, Clinton Co., Pa., by Seth Nelson collecting for

Mr. S. N. Rhoads, which he identified as this species. I exam-

ined it at the time and I have no doubt as to the correctness of

the identification. Unfortunately the specimen cannot now be

found.

Thamnophis sauritus (Linné).— This is a rather common snake

throughout the lowlands and probably the mountains also. I

have seen specimens from the Pocono plateau, Pa., and Swartz-

wood Lake, N. J., but not as yet from the main Alleghany range.

Thamnophis sirtalis (Linné ).—'T'he Garter Snake is distributed

"Proc. Acad. Nat. Sci. Phila., p. 662, 1905.

No. 471] PENNSYLVANIA REPTILES AND BATRACHIANS 165

all over the region under consideration and presents several more

or less distinct types of coloration. So far as the material avail-

able for examination is concerned it would seem that the dark

form with the stripes nearly obliterated, T. s. ordinatus, is re-

stricted to the higher Alleghanies as the only specimens are from

Sullivan and Wyoming Cos. (Stone) and Port Alleghany, McKean

Co. (Fowler). All the specimens that I have seen from south

of the mountains are true sirtalis with well defined stripes and

usually conspicuous spots. Those obtained by Rhoads at Round

Island, Clinton Co., Pike Co., Pa., and Sussex Co., N. J., are

somewhat intermediate. ‘That these two forms are not absolutely

coincident with the Canadian and Carolinian-Alleghanian belts

as indicated, is shown by the fact that a fairly typical sirtalis was

obtained on the high Alleghanies of Sullivan Co., Pa. A nearly

uniform green specimen, “T. s. gramineus " Cope, was also ob-

tained at the latter locality. This I take to be a mere color form

of ordinatus.

Thamnophis butleri Cope.— While for some years Thamnophis

brachystomus Cope has been regarded as a mere abnormal example

of T. sirtalis, the recent discovery of a number of specimens in

Michigan! seems to establish its distinctness. The type is from

Franklin, Venango Co., Pa. (Miss A. M. Brown) and I am now

able to record an additional Pennsylvanian specimen obtained

at Port Alleghany, McKean Co., Aug. 19, 1904, by H. W. Fowler.

This individual has the plates as follows: upper labials, 6-6;

lower labials, 6-7; postoculars, 2-2; gastrosteges, 136; uro-

steges, 47; length, 377 mm. It presents the principal additional

characteristics of the species in a marked degree, 7. e., the rapid

tapering toward both head and tail, and the very slight constric-

tion at the neck. The lateral stripe is mainly on the third row of

scales involving part of the second and at some points part of the

fourth row.

After the above was written Alex. G. Ruthven examined the

two specimens and pronounces them in his opinion identical with

T. butleri a conclusion which he had already reached in connection

with Dr. Clark's specimens.’

'H. L. Clark. Proc. Biol. Soc. Wash., vol. 16, pp. 83-88, 1903.

*Biol. Bull., vol. 7, no. 5, Nov., 1904.

166 THE AMERICAN NATURALIST [Vor. XL

Regina leberis (Linné ).— This does not appear to be a common

species and I have never seen it alive. Two specimens marked

“ Pennsylvania ” (J. L. Wortman ) are in the Academy collection

as well as specimens from Philadelphia (J. E. Ives), Waynesburg,

Green Co., Pa. (Rhoads), and Newark, Del. (Dr. T. B. Wilson ).

Natrix sipedon (Linné ).— Common in suitable localities through-

out the region.

Calopeltis obsoletus (Say ).— I have only taken this snake in

Chester Co., Pa., but have examined several from southern New

Jersey, one of which was obtained on the coast at Stone Harbor,

by D. McCadden.

Calopeltis obsoletus confinis Baird & Giraud.— One young

specimen secured many years ago at Dennisville, Cape May Co.,

N. J., by Samuel Ashmead is in the Academy collection, and an-

other was secured at Diamond Valley, Huntingdon Co., Pa., Sep-

tember, 1905, by J. A. G. Rehn. While currently referred to this

form it seems probable that these are nothing more than young

obsoletus which at this age may be highly colored, but so far as I

know there is no description of the young of this species. The

specimens before me are gray with brown spots.

Opheodryas sstivus (Linné).— I have taken this in the south-

ern part of New Jersey only, and have seen no specimens from .

elsewhere in the district under consideration. It is locally rather

plentiful.

Liopeltis vernalis (DeKay ).— A common species throughout

the Pennsylvania mountains, McKean Co. (Fowler), Sullivan and

Wyoming Cos. (Stone), Clinton Co. (Rhoads), Monroe Co. (C.

T. Sands). The only New Jersey example that I have seen was

taken at Trenton, N. J., by Dr. C. C. Abbott.

Bascanion constrictor (Linné).— Common in the low grounds

and at least onto the first ridges of the mountains and though I

have not as yet seen a specimen from the main Alleghany range,

it no doubt occurs there.

Pituophis melanoleucus (Daudin ).—The commonest large snake

in the New Jersey pine barrens but I have not seen specimens

from farther north in the State nor from Pennsylvania.

Diadophis punctatus (Linné).—Sparingly about Philadelphia

but more plentiful nearer to the mountains, over which it ranges.

Specimens examined from

No. 471] PENNSYLVANIA REPTILES AND BATRACHIANS 167

Pennsylvania, Bucks Co. (W. A. Shryock), Cumberland Co.

(Rhoads), Lancaster Co. (Stone), Monroe Co. (Rhoads), Har-

vey’s Lake, Luzerne Co. (Stone);

New Jersey, Morris Co. (Dr. Fisher ).

Lampropeltis getulus (Linné).— A rather common species in

southern New Jersey, the most northern record being Pt. Pleasant,

Ocean Co. (S. Brown). All the specimens I have examined came

from the eastern and western edge of the pine barrens rather than

from the heart of the region though this may have been accidental.

Rhoads obtained this snake at Seaford, Del., but I have never

seen a specimen from Pennsylvania.

Lampropeltis doliatus (Linné).—One typical specimen from

Delaware (J. Green) is in the Academy collection and another

not quite typical from the same State obtained by Drexler.

Throughout the greater part of eastern Pennsylvania and New

Jersey is found L. d. clericus and it is everywhere a common snake

unless it be in the New Jersey pine barrens from which district I

have seen no specimens. Another race, L. d. triangulus (Boie),

seems to be the form of the higher mountains and is represented

in the Academy collection by a specimen from McKean Co., Pa.

(Fowler) and one marked near Philadelphia. More material will

be necessary in order to ascertain whether these two forms are

constant and confined to the districts assigned to them. Certain

it is that examples from twenty localities south of the mountains

are all clericus, the Philadelphia specimen above mentioned being

the only exception.

Heterodon platyrhinos Latreille.— Common, ranging from the

Alleghanies across to the coast.

Agkistrodon contortrix (Linné).— Becoming scarce in thickly

settled distriets. I have seen it in York and Fulton Cos., Pa.,

and have examined specimens from Carbon Co. (Rehn), Lehigh

Co. (Rehn), Pottsville (C. T. Hughes), Round Island, Clinton

Co. (Rhoads), Pa. I have seen no specimens from New Jersey.

Crotalus horridus (Linné).— I have found this species within

the past few years on the foothills of the main Alleghany Moun-

tains near Lovelton, Wyoming Co., and on Tuscarora Mt., Fulton

Co., Pa., while Rehn collected several in Huntingdon Co. and

Rhoads obtained specimens at Round Island, Clinton Co., and

168 THE AMERICAN NATURALIST [Vor. XL

in Pike Co., Pa., and I have examined additional specimens from

Chambersburg (Mrs. P. P. Calvert) and Warren Co., Pa. (Dr.

Slack). In the southeastern parts of the State it is exterminated.

In southern New Jersey it is very rare and I know of no authentic

recent records though there is a specimen in the Academy collec-

tion collected many years ago at Pemberton, N. J. (Dr. Coleman ).

Eumeces fasciatus (Linné).— I have taken this lizard at York

Furnace, York Co., Pa., and J. A. G. Rehn obtained it on the

mountains of Huntingdon Co., Pa., where one would rather expect

E. anthracinus, a species which I know from the State only on the

strength of Baird’s Carlisle record. In New Jersey it occurs at

May’s Landing, Jones Mill, and doubtless other spots in the pine

barrens. In Delaware I have found it about Choptank Mills.

One in the Wagner Institute collection, captured in Fairmount

Park, Philadelphia, a few years ago, may have escaped from con-

finement like the specimens of Phrynosoma and Alligator which

are occasionally found within the city limits.

Leiolepisma laterale (Say ).— On September 2, 1901, J. A. G.

Rehn and I caught one of these little lizards and saw another a

mile or so east of Atsion, Burlington Co., N. J., in the heart of the

pine barrens. Dr. J. P. Moore had previously taken it at Pleasant

Mills some ten miles farther south.

Sceloporus undulatus (Daudin ).— Abundant all over the pine

barrens of New Jersey, but I have not seen it from north of this

region. In Pennsylvania it is rare, though formerly more com-

mon. I have only taken it along the lower Susquehanna valley,

in York and Lancaster Cos., though Rhoads obtained it at Round

Island, Clinton Co., and I have examined a specimen collected in

Chester Co. by Cope.

Dermochelys coriacea (Vandelli).—One was washed ashore at

Asbury Park, N. J., some years ago, and another from Delaware

Bay is in Cope’s collection.

Aspidonectes spinifer (Le Suer ).— A few of these turtles have

of late years found their way into the Delaware valley. One was

captured in Cooper’s Creek, N. J., in 1902, and another in Warren

Co., N. J., now in the Wagner Institute collection, Philadelphia.

I have also examined specimens from the Alleghany River in

western Pennsylvania.

No. 471] PENNSYLVANIA REPTILES AND BATRACHIANS 169

Chelydra serpentina (Linné ).— Widely distributed throughout

the region.

Kinosternon pennsylvanicum (Bosc. ).—I have so far found this

species only in southeastern Pennsylvania and southern New

Jersey, ranging as far north as Sea Girt (Rhoads ).

Aromochelys odoratus (Latreille).— Apparently more abun-

dant than the preceding and of wider range. I have seen it from

the same general region as the above and also from Swartzwood

Lake, Sussex Co., N. J. (Rhoads).

Graptemys geographicus (Le Suer).— I found a carapace and

plastron of this turtle on the marsh at Bayside, N. J., in the spring

of 1903.

Malaclemmys centrata (Latreille)J.— I have examined speci-

mens from Cape May, N. J. (Dr. Ruschenberger ) and the coast

of Delaware but have only one recent record, a specimen in the

Wagner Institute collection in Philadelphia, captured in Dias

Creek, Cape May Co., N. J., a few years ago. It has become

rare within the district under consideration.

Pseudemys rubriventris (Le Conte ).— I have seen this turtle in

ponds and slow streams at several points in southern New Jersey,

especially at Medford and Milford and have examined specimens

obtained at Woodbury and Rehoboth Beach, Delaware (T. R.

Peale). One in the Academy collection is marked “ Delaware

River, Philadelphia.”

Chrysemys picta (Hermann ).— This species is abundant in

most large streams and ponds throughout the district though I

have no data upon its occurrence on the Alleghanies.

Clemmys muhlenbergi (Schweigger).— I have seen probably a

dozen specimens of this turtle in W. Bradford township, Chester

Co., Pa., and several in Tinicum, Delaware Co. In New Jersey

I secured one at Medford, May 30, 1905, and found another near

Audubon, Camden Co., in December. The only other specimens

that I have examined were labeled “ near Philadelphia."

Clemmys insculptus (Le Conte ).— Apparently wide ranging but

not very common. I have taken it in Chester and Fulton Cos.,

Pa, and have examined the following additional specimens:

Bristol, Pa. (Fowler), Round Island, Clinton Co., Pa. (Rhoads ),

Delaware Gap, Warren Co., N. J. (Rhoads), and Woodbury, N.

J. I have no record for the pine barrens.

170 THE AMERICAN NATURALIST [Vor. XL

Clemmys guttatus (Schneider ).— All over southeastern Penn-

sylvania and southern New Jersey, including the pine barrens but

as to its occurrence in the higher mountains I am in doubt.

Terrapene carolina (Linné).— Common throughout southeast-

ern Pennsylvania especially in Chester Co., and also in the south-

western part of the State, Waynesburg, Green Co. (Rhoads ).

For New Jersey my data are meager but I have no record for the

pine barrens. The species seems to be restricted to the Caro-

linian fauna. "Two specimens of T. triungius Agassiz are in the

Academy collection labeled *' Cistudo clausa, near Philadelphia,

S. G. Worth." 'The labels must surely have been transposed as

this is quite beyond the range of the species.

ANATOMY OF ACMEA TESTUDINALIS MULLER

PART I. INTRODUCTORY MATERIAL— EXTERNAL

ANATOMY

M. A. WILLCOX

INTRODUCTION

SOME months ago I published in this journal under the title

“Biology of Acmea testudinalis Müller” an excerpt from a mono-

graph of this species upon which I have long been engaged.

I have now decided to publish the entire monograph in sections

of which the present is the first. It should naturally be introduced

by remarks upon the scope of the work but as these were prefixed

to the earlier article, I refer the reader to that, adding merely that

the investigation is intended not only as a contribution to a knowl-

edge of the New England fauna but also as a first step in such a

careful comparative study of the different species of the genus as is

there suggested. This being its aim, it occupies itself in the main

with anatomy, touching only incidentally upon either histology or

embryology. I have, moreover, tried tomake a paper which would

serve as an introduction to the study of the neglected but fascinat-

ing group of Gastropoda. This aim will, I trust, serve as excuse

for the admission of some material too elementary to be included

in a paper addressed exclusively to specialists.

ZOOLOGICAL POSITION OF ACMA AND ITS ALLIES

Acmea belongs to the Scutibranchiata (Aspidobranchia, Dioto-

cardia of Bouvier et al.), a suborder which includes all the more

primitive Prosobranchiata and which is divisible into two sections:

the Rhipidoglossa (Diotocardia of Remy Perrier) and the Doco-

glossa (Heterocardia). The only characteristics by which mem-

bers of these two sections may infallibly be distinguished are

first, the nature of the radula and second, the presence of dialy-

171

172 THE AMERICAN NATURALIST [Vor. XL

neury in the nervous system of the Rhipidoglossa and its absence

in the Docoglossa. Dialyneury, it will be remembered, is the

name applied to that form of nervous system in which the mantle

is innervated in part from the pleural and in part from the visceral

ganglia and in which these two systems of nerves are connected

by anastomosis. It may be added that the ventricle in Rhipi-

doglossa is usually traversed by the rectum although the Heli-

cinidee, which have but one auricle, are an exception to this rule.

The Rhipidoglossa fall into two subsections: the Zygobranchia,

characterized by the possession of two gills and two auricles, which

are usually symmetrically disposed, although one gill may be

smaller than the other; and the Azygobranchia with but one gill

and ordinarily with two auricles, one of which is more or less

rudimentary or even absent altogether. The Docoglossa have a

single gill (ctenidium) or none at all, a single auricle with no trace

of a second,‘ and a heart whose ventricle is never traversed by the

rectum. It is thus evident that the three divisions of Scutibran-

chiata form in many respects a continuous anatomical series

whose members, whatever the view as to their phylogenetic rela-

tionship, may often be profitably compared.

The Docoglossa? include three families: the Lepetidie, Acmæi-

dee, and Patellide. The Lepetide is a small family whose mem-

bers inhabit water of considerable depth. Of its fourteen species

and varieties only one is recorded as living at low-water mark;

the others have been dredged at depths varying from ten fathoms

(five fathoms in one instance) to thirteen hundred ninety-five

fathoms. While in certain respects, as in the shell and radula,

they exhibit relationship to the Rhipidoglossa, in others they are

modified in correlation with their environment so that they appear

to be, as maintained by Dall, less typical Docoglossa than are the

others. The family contains three genera: Lepeta, (including

Pilidium), Propilidium, Lepetella.

The two remaining families are much larger and are typically

‘ Spillmann (:05, pp. 569-571) considers that he has found traces of a

second auricle.

In the classification of the Docoglossa I follow Pilsbry (Tryon and Pilsbry,

91).

No. 471] ANATOMY OF ACMEA TESTUDINALIS 173

litoral animals. The first one, the Acmæidæ, comprises those

limpets which retain the primitive gill (ctenidium) with or with-

out a cordon of branchial leaflets; the second, the Patellide,

comprises those which lack a ctenidium but have a branchial

cordon. The Acmeide contains three genera: Pectinodonta,

with one species, a deep-sea form found off some of the West

Indian islands; Acmæa, with eighty-four species, of almost world-

wide distribution; Scurria (including the subgenus Lottia), whose

five species are found only on the West American coasts, as far

north as San Francisco. ‘The Patellidz contains also three gen-

era: Patella (including the subgenus Helcion and the sections

Patina, Scutellastra, Ancistromesus, all often regarded as genera),

with forty-eight species which with one exception (P. mexicana)

are entirely restricted to the Old World; Nacella, whose seven

species are found only in the region about the southern part of

South America; Helcioniscus, with forty-eight species in various

portions of the Indian and Pacific Oceans but not extending on

the American coast farther north than Chili.

History oF INVESTIGATION

The name Patella (Acmea) testudinalis first appears in 1776

in Miiller’s Prodromus but more than fifty years went by before

any record was made of so obvious a feature in its anatomy as the

possession of a ctenidium. It was the observation of this fact

which led Eschscholtz to establish in 1830 the new genus Acmea.

As is well known, his early death left uncompleted the Zoologischer

Atlas which was to have embodied the results accumulated during

the years of his circumnavigating voyages. Such material as was

in condition to be used by another was completed by his friend

Rathke and published in 1833 as a fifth part of the Atlas. It con-

tained an anatomical account, covering two folio pages, of the

new genus Acmza followed by brief descriptions, dealing with

only the shells, of eleven species collected by Eschscholtz in the

neighborhood of Sitka.

This first anatomical study is purely description and is of merely

historie interest. The points touched upon are only the more

174 THE AMERICAN NATURALIST [Vor. XL

obvious ones; the account contains some unquestionable. errors

and some statements which if correct, do not apply to all members

of the genus.

A step in advance was marked by Dall's successive papers on

the limpets of which the first appeared in 1869. ‘These papers

deal mainly with the Acmeide and although preéminently sys-

tematic, contain occasionally anatomical facts of interest and

importance.

The first considerable contributions to the morphology of

Acmæa are contained, however, in two papers on the compara-

tive anatomy of certain organs of Prosobranchs which issued

from the laboratory of Professor E. Perrier about fifteen years ago.

The first of these papers, (Bouvier, ’87) dealt with the nervous

system; the second, (Bernard, '90) with the pallial organs. Bou-

vier ('87, pp. 15-22) gives a full and careful description of the

nervous system of Patella and in a single paragraph compares

therewith the very similar one of A. testudinalis. Bernard de-

scribes in detail the osphradium and the innervation of the gill

in a species of Tectura (Acmza) and in the same connection fig-

ures and describes the arrangement of the principal ganglia in

what he calls T. fontainesi. It should be noted that this latter

species is without doubt, as I have shown elsewhere, (Willcox, 00)

incorrectly named and that the identification of the other, so far

as concerns the species, is questionable. The so called Tectura

fontainesi, having circumpallial branchial lamelle (Bernard, '90,

p. 217) is of course not a true Tectura (Acmxa) but may very

probably be a Seurria. T. pileopsis, Bernard's other species, is

stated by him (90, p. 217) to have come from Chili but that spe-

cies is recorded by Pilsbry (Tryon and Pilsbry, '91, p. 57) as be-

longing to the New Zealand, Indo-Pacific, and Australian region.

The first work in which Acmxa was treated monographically

was Haller's Studien über docoglosse and rhipidoglosse Proso-

branchier, which appeared in 1894. This deals with one species

of Seurria and three of Acmæa and as it treats all the important

organs of the body except the shell, it would at first sight seem to

render superfluous further work upon the small family of Ac-

mæidæ. Various statements made by Haller have, however,

been the object of vigorous criticism and in other particulars which

No. 471] ANATOMY OF ACMEA TESTUDINALIS 175

have not yet come under publie discussion I have found myself

unable to adopt his views or to confirm his observations. It is

unfortunate that of Haller’s four species three are incorrectly

named (cf. Willcox, :00). One, Scutellina galathea, is in all

probability an Acmæa but its specific name can only be surmised;

for his two other Acmxas he employs the name Lottia, a synonym

which was not only discarded by its author some sixty years ago

but which has been since 1865 in use for another genus or sub-

genus, so that the Lottia of Haller is an entirely different animal

from the Lottia of Carpenter and modern authors in general.

In' 1898, appeared a brief monographie account by myself of

A. fragilis. This paper dealing as it did entirely with preserved

material which was studied almost exclusively by means of sections,

left room for such completion and enlargement as is presented in

the present work. In 1904, appeared an excellent paper on the

anatomy of Lottia gigantea by W. R. Fisher to which I shall fre-

quently have occasion to refer. The latest contribution is an arti-

cle by Spillman in which (:05, pp. 553-564, 568-572) the heart

and vessels of Acmeea are described.

Other papers which in the last decade have discussed the Ac-

meeidee have been occupied mainly with criticism of some of Hal-

ler’s statements and with the presentation of counter observations.

The chief matters in dispute have been the existence of a ccelom

as distinct from the pericardial, nephridial, and gonadial cavities,

the extent of the nephridium, the presence of a subradular organ.

The chief disputants have been Haller, Pelseneer, Thiele, Willcox.

METHODS

The first problem which faces any student of the Mollusca

relates to narcotization. This is a much less important question

among the limpets than in most other groups since the form of

the body is such that no great amount of distortion can be effected

even by the most powerful contraction. Proper extension of

mantle and tentacles are the main results to be attained. For

these purposes I have employed various methods — Epsom salts,

cocaine, chloretone, stale sea water, fresh water. No one of these

176 THE AMERICAN NATURALIST [Vor. XL

methods was altogether successful. The cocaine — a 2% solu-

tion in 50% alcohol added drop by drop — produced extension of

gill and cephalic tentacles. In specimens killed after this treat-

ment, the subradular organ was likely to be extruded. Chlore-

tone — crystals gradually added to sea water — produced at first

a general extension but a larger dose brought about contraction.

This agent is especially useful for narcotizing parts — as gills or

tentacles — which it is desired to study while still alive. Exten-

sion of mantle tentacles is best obtained by killing in Gilson's

fluid, extension of the mantle in general by this method or by

allowing the animal to die in stale sea water, or, as recommended

by Fisher, in fresh water.

'The most satisfactory killing agents I have found to be picro-

sulphuric acid, chrom-alcohol (equal parts of 70% alcohol and

"1, % chromic acid), and corrosive sublimate with 5 to 20% of acetic

acid. A weak — 5% — aqueous solution of sublimate preserves

the external cilia better than a stronger one; this solution also I

have employed with success for material in which it was desired

to demonstrate mucus. The various osmic acid solutions — vom

Rath's, Hermann's, Flemming's — have no marked superiority

except for demonstrating certain glands as noted in the section on

the integument. Picro-sulphuric acid has the advantage when

used for very small specimens, of decalcifying the shell while leav-

ing it in situ; in specimens killed in corrosive acetic the shell

parts from the animal, in consequence I suppose of the pressure

due to the more rapid evolution of gas brought about by the

larger proportional amount of acid. An acid killing agent, as

Bernard has pointed out, is desirable because it at once coagulates

the mucus and thus renders the goblet cells more conspicuous.

For purposes of dissection it is desirable to have some specimens

killed in formalin. The comparative transparency produced by

this agent as well as its slight swelling action are often of advan-

tage; it has the further good quality that it preserves at least for

some time the color of the nephridial epithelium. A 2% solution

is most satisfactory and it is of course desirable that the solution if

acid should be neutralized. Opaque specimens for dissection are

best killed in Gilson's fluid. It is perhaps unnecessary to add

that details can often be made out better in specimens in which

No. 471] ANATOMY OF ACMA TESTUDINALIS 177

the pressure on the viscera entailed by the contraction of the foot

has been done away with either by removal of this organ or by

slitting it lengthwise and thus opening the visceral cavity.

Sections were prepared by imbedding in paraffin, were stained

usually with hzemalum and eosin or with Ranvier’s picrocarmine

and methylen blue, and were mounted in xylol balsam. For dem-

onstration of mucus Mayer’s mucicarmine was employed on sec-

tions of material killed in 5% sublimate solution. Endothelium

was demonstrated by bathing the fresh membrane for half an hour

in a mixture composed of four parts saturated aqueous solution of

methylen blue and 96 parts fy% salt solution, then leaving it for

some hours in a saturated solution of ammonium picrate. Speci-

mens thus prepared were mounted in glycerine saturated with

ammonium picrate and have kept well for some years.

For macerations, good results have been obtained with Haller’s

fluid (cf. Lee's Vademecum, 4th ed., p. 318) and Bernard’s fluid

(Bernard, ’90, p. 101).

Total preparations showing the innervation of thin structures

like the mantle or the gill were most successful when stained with

methylen blue and mounted in glycerine surcharged with ammo-

nium picrate. Such preparations are fairly permanent.

HABITS

Here should be intercalated the article on the biology of Acmæa

already mentioned. To the facts there stated I have only to add

that I have occasionally found in the nuchal cavities of specimens

collected at Eastport tiny shells, measuring about one mm. in

diameter which have been identified for me by Mr. Charles W.

Johnson of Boston as in all probability the young of Lacuna neri-

toidea Gould. Whether these are commensals or merely accidental

visitants I am not prepared to say.

The literature dealing with this section is incorporated in the

list at the close of the present article. The statement by Dall

that fertilization is internal was published not in 1879 but in 1882.

178 THE AMERICAN NATURALIST [Vor. XL

(GENERAL DESCRIPTION

Acmea testudinalis, like the limpets in general, has a somewhat

dish-shaped shell, (Figs. 1 and 2), roughly conical in section and

with a mouth (corresponding to the base of the cone) which is

broadly oval though with the anterior part a trifle narrower than

the posterior. The apex of the shell lies not over its center but

about one third of the distance from the anterior end. It may be

A $

; |

A : y

Fig. 1. Fic. 2.

Fic. 1.— Acmaa testudinalis. Ventral view. X 13. Whole on Re the excep-

tion of the mantle, strongly contracted. c., ctenidium; f., foot; l, lip sur-

rounding the circular mouth which is dilated to show vat inner i between

which appears the dark radula; m., mantle; t., uroer Camer:

Fig. 2.— Acmea testudinalis. Side view. Xx 1}.

worthy of mention that the true, or docoglossate limpets and the

keyhole limpets (Fissurellide) differ in this respect from all the

other widely dissimilar genera to which this form of shell is common

and in which the apex, though varying in position in different

forms, is never anterior. The condition in Acmza is a secondary

one for Boutan (’98, p. 1869) finds that in A. virginea the apex is

at first posterior and only in course of development assumes the

adult position.

In color the shell is usually yellowish gray marked with radiat-

ing stripes or tesselations of dark brown. ‘The extent and the tint

of the markings vary greatly and they are sometimes almost or

quite absent. The hypostracum, or inner layer of the shell, stops

a little short of its edge so that on the internal aspect the markings

appear as a narrow border. This I understand to be the “more or

less distinct internal border of the aperture,” mentioned by Tryon

and Pilsbry (’91, p. 5) as a character by which the Acmeeide are

No. 471] ANATOMY OF ACMEA TESTUDINALIS 179

usually distinguished from the Patellide. While the family to

which a limpet belongs may often be thus recognized, the genera

at least of the Acmeide, cannot according to Pilsbry, be deter-

mined by a study of the shells alone.

In the living animal the mouth of the shell i is almost entirely

filled up by the foot, a broad fleshy expansion of the ventral body

surface which apparently serves as a sucking disc! to hold the ani-

mal to the rocks on which it lives. The organ is composed chiefly

of muscle fibers most of which run from the shell ventralward,

spreading both laterally and toward the median line. A few fibers,

however, are parallel with the sole and run either lengthwise or

transversely. The fibers are imbedded in connective tissue and

are entirely wanting near the margin of the foot, which is com-

posed mainly of connective tissue excavated by large blood sinuses

and is therefore extremely flexible. ` Certain marginal unicellular

glands, whose secretion may aid the foot in clinging, are described,

together with the epithelium in general, under the topic Integu-

ment. Just in front of the foot appears a ventral prolongation of

the head, the muzzle; it bears on its tip the small circular mouth

surrounded by the simple frill-like lip, which is characteristic of

the subgenus Collisella. In a specimen which has been narcotized

with chloretone the mouth is usually dilated enough to show the

yellowish brown inner lips (Fig. 1) and in a fresh one its continual

opening and closing permits a good view of the radula, which has

a constant licking motion. It has been suggested by Davis and

Fleure (:03, p. 49) that this movement serves to keep in motion

the blood in the cireumodontophoral sinus and thus reinforces

the feeble ventricular muscles.

At the sides of the muzzle appear a pair of long and very con-

tractile tentacles; they are borne on the posterior part of the head

and each carries on the outer side of its base a simple optic pit

which in the living animal or in a formalin specimen appears as a

spot of black pigment.

In front of the head or at the right of the foot the etenidium, or

gill may usually be seen. When fully extended this organ is nearly

' This almost universally accepted view has been controverted by Davis

(95; Davis and Fleure, :03, pp. 4, 15) but the arguments do not seem to

me conclusive.

180

THE AMERICAN NATURALIST

[Vor. XL

one half as long as the entire animal; it is attached to the poste-

rior wall of the nuchal cavity so that its distal end alone is visible

Fie. 3.— Acmaa testudi-

nalis. Nuchal cavity.

x 2. Columellar mus-

cle cut and roof of cham-

ber turned bac

anal papilla; c., cteni-

dium; cm., columellar

muscle; f., foot; In., rn

left and right nephridial

papill®; o., osphradium;

pericardium; pm.

(Fig. 3). Itisa somewhat plume-like organ;

the shaft of the feather is represented by a

flattened triangular lamina, very long and

very narrow, which bears on its flattened

dorsal and ventral faces the structures cor-

responding to the barbs. ‘These are two

series of flattened more or less semicircular

sacs each of which runs transversely across

the shaft so that its cavity communicates

with each of the two lateral vessels described

below.

Blood is conveyed through the gill by

means of two vessels each of which occu-

pies one margin of the shaft. That on the

pallial muscle E

right edge conveys blood from the suprarenal

plexus (cf. p. 184) to the gill, that on the left carries blood from

the gill to the auricle. In the living animal the gill is usually so

rotated that the efferent vessel alone is visible.

Attachment of the shell is effected by a band composed of the

pallial and the columellar muscles (Fig. 4). The pallial muscle

is ring-like and its fibers extend from the shell into the mantle.

The columellar muscle is horseshoe-shaped and lies just internal

to the pallial muscle from which it is separated by no sharp bound-

ary; its fibers run from the shell into.the foot and it is of course

interrupted anteriorly where the head is interposed between these

two structures.

From this muscle band depends the mantle, a thin, tentacle-

fringed, membranous fold which lines the marginal part of the shell

and in front of the columellar muscle runs up to the apex. In this

region it forms the roof of a deep cavity, the nuchal cavity, which

lies above the head and neck and is bounded at the sides and be-

hind by the columellar muscle and the front part of the visceral

mass. Elsewhere the mantle forms the outer wall of a groove-like

space, the mantle groove, enclosed between it and the foot. Mantle

groove and nuchal cavity are of course continuous; both together

constitute the mantle cavity.

No. 471] ANATOMY OF ACMEA TESTUDINALIS 181

* The dorsal part of the body is in the main developed into the

convex visceral mass, but just above the anterior part of the foot

it suddenly contracts into the neck (Fig. 2) and this, passing for-

ward and slightly enlarging, gives rise to the head which curves

ventralward and ends in the so called muzzle, thus bringing the

mouth to lie flush with the foot. The head consists of a thin,

muscular wall which in the region of the muzzle is fused with the

pharyngeal walls but farther back is separated from them by a

large blood sinus.

The visceral mass contains the digestive tract, blood vascular

system, reproductive glands, and nephridia. It is covered by a

green epithelium which immediately underlies the shell and may

readily be brushed away. ‘This being done, parts of all the above-

mentioned organs may be made out through the thin body wall

though they can be seen somewhat more readily in a specimen

preserved in Gilson's fluid or formalin.

In such a preparation (Fig. 4) one notices first the band com-

posed of pallial and columellar muscles; it is divided into a series

of fascicles by blood vessels which cross it. External to the muscle

ring is the mantle, fringed with its tiny tentacles and marked on

the edge with a band of pigment whose alternations of light and

dark tint have a general correspondence with the light and dark

radial markings of the shell. In this region the mantle is thick-

ened by the presence of a mass of unicellular glands of uncertain

function. Just internal to the pigment band is a zone, often con-

tracted to extreme narrowness, which represents the thin, non-

glandular part of the mantle. Internal to the anterior curve of the

pallial muscle and between the ends of the columellar muscle is a

pellucid space, the roof of the nuchal cavity, in which may be noted

traces of a blood plexus and through which the outlines of the

ctenidium and the head may be more or less clearly seen.

Turning now to the visceral mass we note just internal to the

columellar muscle and pericardium (see below) the edges of the

generative gland; the bulk of the organ lies in the ventral part of

the body directly above the foot, but its margins, especially the left

one, curve dorsalward until they immediately underlie the nephri-

dium through whose thin walls they are more or less clearly to be

seen. Internal to the pericardium a small portion of the gland is

182 THE AMERICAN NATURALIST [Vor. XL

always distinctly visible. In the apical part of the visceral mass is

the digestive gland; partly imbedded in it and partly lying between

Fia. 4.— Acmea testudinalis. Dorsal view X shell gi un. epithelium

removed. x 4. d., ee c., cten: nn cm., mellar aee enclos-

ing the en cavity and visceral m an ie ir e ring; d.,

digestive gland; e., eye; I., generative land: gm., glandular zone sind mantle;

cardium; rm

and obscures the external pallial vessel. The rectum, un marked, lies be-

tween the — gland and the right nephridium, For names of | blood

ls see te 'Two of the

lines at the leti; diebus they underlie and are obscured by the horizontal

interfascicular vessels, Outlines drawn with camera, details combined from

several specimens,

it and the generative gland are portions of the coiled alimentary

tract especially the obliquely-running posterior end; sometimes a

bit of the radula appears near the middle of the gland. On the left

No. 471] ANATOMY OF ACMEA TESTUDINALIS 183

side, abutting against the anterior portion of the columellar muscle

is a pellucid triangular space, the pericardium. ‘This space lies

for the most part in the anterior, nearly vertical wall of the visceral

sac and may in a preserved specimen of a ripe Acmæa be almost or

quite hidden by the generative organ, which seems to overlie it.

Such an appearance is, however, an artefact, being due to a folding

of the anterior wall brought about by strong contraction. Behind

the pericardium and abutting against the whole remaining extent

of the columellar muscle lies the dorsal portion of the right nephri-

dium; the ventral part of the organ occupies the right half of the

ventral face of the visceral mass directly underlying the generative

gland and is, of course, invisible from above. The marginal part

of the dorsal nephridial wall is especially conspicuous for this is

produced dorsally into numerous branched coeca that immediately

underlie and are grown to the dorsal integument. Anteriorly the

nephridium not only occupies the margin of the visceral sac but

sends from its right limb toward the median line a large branched

lobe which reaches and in part overlies the end of the intestine.

On the left of the rectum between it and the pericardium, may be

distinctly seen the small left nephridium, partly overlying the

rectum.

The structures thus far described may, as has been stated, be

made out more satisfactorily in a preserved specimen; the blood

vessels now to be enumerated can be studied to much better advan-

tage in a living animal though some of them are distinguishable in

a preserved one. An Acmæa which has been kept in water of 15°

to 25° C. until dead or dying is well relaxed. In such a specimen

some at least of the mantle nerves may often be seen and it usually

shows clearly the following vessels:—

1. Internal pallial vessel (Mantelrandvene or Mantelrand-

arterie of Haller), which lies just outside and beneath the pallial

muscle and, like it, forms a complete ring.

2. Perivisceral vessel, a U-shaped vessel lying just inside the

columellar muscle. On the right it is continued around the end

of this muscle and across the pallial muscle to the internal pallial

vessel; on the left it ends just behind the pericardium, where it

falls into one of the horizontal interfascicular vessels.

3. External pallial vessel (pallial vein of authors), which forms

184 THE AMERICAN NATURALIST [Vor. XL

a second ring around the margin of the mantle at the base of the

glandular zone.

4. The horizontal interfascicular vessels (Quervenen of Haller),

a series of vessels which cross the columellar and pallial muscles

connecting the perivisceral and the internal pallial trunks.

5. The vertical interfascicular vessels, a series of vessels which

run up from the foot in the columellar muscle, join each with a

horizontal interfascicular vessel and so connect with the internal

pallial.

6. The mantle plexus. This consists of a dorsal and a ventral

network. The vessels of the ventral network arise from the inter-

nal pallial trunk and the ultimate branches end blindly in the

glandular zone. The vessels of the dorsal network arise from the

external pallial trunk and end blindly in the non-glandular zone

of the mantle. In a view such as we are describing the two net-

works are indistinguishable.

7. The transverse pallial vessels. One or two vessels, which

arise from the external pallial trunk opposite the left end of the

columellar muscle, unite (if two are present) and curve around the

muscle to the auricle. In a relaxed specimen such as we are de-

scribing they cannot be traced to the auricle but in a perfectly

fresh animal their pulsation is readily seen.

8. Indications of a suprarenal plexus (periintestinales Venen-

netz of Haller). ‘The distal ends of the nephridial coeca are grown

to the dorsal body wall and the blood sinus in which they lie is

thus broken up into a series of connecting spaces.

9. Supravisceral vessels, which ramify over the dorsal surface

of the digestive gland and open eventually into the suprarenal

plexus. I have been most fortunate in finding these dorsal vessels

showing clearly in specimens preserved in Gilson’s fluid in which

the contraction had been reduced to a minimum either by nar-

cotizing with chloretone or by slitting the muscles of the foot.

10. Ctenidial vessels. In a preserved specimen one may see

through the wall of the nuchal cavity the ctenidium with its dorsal

series of lamellae and the afferent and efferent vessels running

respectively along its right (posterior) and left (anterior) edges.

The afferent vessel brings blood from the suprarenal plexus, the

efferent one carries it to the auricle. At the base of the gill may

No. 471] ANATOMY OF ACMHA TESTUDINALIS 185

be seen small opaque patches, the expression of interspaces be-

tween vessels that open directly into the auricle or the gill vessels.

Those which open into the afferent vessel come from the anterior

part of the suprarenal plexus; those which open into the auricle

and the efferent vessel come from the nuchal plexus.

The nuchal cavity (Fig. 3), as has been said, lies in front of the

visceral sac and above the head and neck; it is somewhat triangu-

lar in longisection and its posterior wall curves from side to side so

that the cavity is much deeper from front to back in the median

line than laterally. It contains the following structures, which

with the exception of gill and pericardium are borne entirely on

the posterior wall: pericardium with the enclosed heart, ctenidium,

papille of small left and of large right nephridia, anal papilla.

Separate generative openings are absent, as is also a hypobran-

chial gland.

On looking into the cavity from the front, one notices first the

large ctenidium whose line of attachment runs along the mantle

from the left tip of the columellar muscle obliquely back to the

hinder wall of the cavity, where it ends a little on the right of the

median plane. ‘Through the thin posterior wall of the chamber

can be seen the rectum lying near its dorsal edge and extending

from the ctenidium almost to the right tip of the columellar muscle,

where it ends upon a prominent anal papilla. Below the rectum

appears a portion of the large right nephridium. It opens by a

sizable papilla (infra-anal papilla of authors) located at the right

of the anus. Above the rectum, in the triangle included between

it, the gill, and the dorsal edge of the mantle cavity, lies the small

left nephridium; it opens by an inconspicuous papilla (supra-anal

papilla of authors) above and to the left of the anus. Behind and

on the left of the ctenidium is a large triangular space enclosed

between it and the columellar muscle and lying partly in the poste-

rior and partly in the dorsal wall; this is the pericardium. The

osphradia are so inconspicuous as to be readily overlooked; they

are a pair of narrow transverse epithelial ridges which lie on the

neck a little behind the anterior end of the columellar muscle. In

a specimen whose shell was 35 mm. in length the left osphradium

was 2 mm. long and the right 1.5 mm. According to Dall these

Structures are sometimes rendered conspicuous by an orange pig-

ment; I have never seen such specimens.

186 THE AMERICAN NATURALIST [Vor. XL

Previous Investigations.— No extended account of the external

anatomy of Acmæa has hitherto been published; the fullest

description is embodied in a single paragraph by Forbes and

Hanley (53, p. 436). Haller’s description of the mantle and

gill will be discussed in subsequent sections.

LITERATURE

BERNARD, F.

’90. Recherches sur les organes palliaux des gastéropodes proso-

branches. Ann. Sci. Nat., zoöl., ser. 7, vol. 9, pp. 89-404, 10

pls

Boutan, L.

'98. Sur le développement de l'Acmaa virginea. Compt. Rend. Acad.

Sci. Paris, vol. 126, pp. 1887-1889.

Bouvier, E. L.

'87. Systéme nerveux, morphologie générale et isses des gas-

téropodes prosobranches. Ann. Sci. Nat., zoöl., ser. 7, vol. 3,

pp. 1-510, 19 pls.

Dart, W. BH.

'82. On certain Limpets and Chitons from the Deep Waters off the

Eastern Coast of the United States. Proc. U. S. Nat. Mus., vol.

4, pp. 400-414. (Date of volume 1881; date of paper, January,

'95. The deii of Limpets. Nature, vol. 51, pp. 511-512.

Davis, J. R. A., AND FLEunE, H. J.

:03. L.M a C. Memoirs. X. Patella. London, 76 pp., 4 pls.

Do, F.

'33. Zoologischer Atlas. Fünftes Heft, herausgegeben von D. Mar-

tin Heinrich Rathke. Berlin.

Fisugn, W. R.

:04. The Anatomy of Lottia gigantea. Zoöl. Jahrb., Abth. f. Anat.,

vol. 20, pp. 1-66, 4 pls.

Forses, E.

'89. OnaShell Bank in the Irish Sea considered Zoologically and Geo-

logically. Ann. Nat. Hist., vol. 4, pp. 217-223.

No. 471] ANATOMY OF ACM.EA TESTUDINALIS 187

FonBEs, E., ann Han ey, S.

AE A History of British Mollusca and their Shells. Vol. 2.

GEDDES, P.

"79. On the Mechanism of the Odontophore in Certain Molluscs.

Trans. Zool. Soc. London, vol. 10, pp. 485-491.

Hausen, B.

Studien über docoglosse und rhipidoglosse Prosobranchier.

Leipzig, 166 pp., 12 pls.

Piuspry, H. A.

'98 iie Function of the Radula. Proc. Acad. Nat. Sci. Phila. 1898,

SMITH, E. d

:03. A List of Species of Mollusca from South Africa. Proc. Malacol.

Soc. London, vol. 5, pp. 348-402.

SPILLMANN, J.

:05. Zur Anatomie und Histologie des Herzens und der Hauptar-

terien der Diotocardier. Jen. Zeitschr. j. Naturw., vol. 33,

'82-—84. Structural and Systematic Conchology. Philadelphia.

Tryon, G. W., anp Pruspry, H. A.

'91. Manual of Conchology. Vol. 13. Philadelphia.

Wittcox, M. A.

'98. Zur Anatomie von Acmea jragilis Chemnitz. Jen. Zeitschr. j.

Naturw., vol. 32, pp. 411-456, 3 pls.

W TELOOX, M. A.

A Revision of the Systematic Names employed by Writers on the

Morphology of the Acmæidæ. Proc. Boston Soc. Nat. Hist., vol.

29, pp. 217-222.

Wittcox, M. A.

:05. Biology of Acmea testudinalis Müller. Amer. Nat., vol. 39, pp.

325-333.

AFFINITIES OF CERTAIN CRETACEOUS PLANT

REMAINS COMMONLY REFERRED TO

THE GENERA DAMMARA AND

BRACHYPHYLLUM'

ARTHUR HOLLICK AND EDWARD C. JEFFREY

INTRODUCTION

Tus paper is a preliminary contribution, designed to demon-

strate the value of critical examinations of paleobotanical mate-

rial by means of the microscope. The results obtained by such

examinations of three kinds of Cretaceous fossil plant remains

are described, viz.: cone scales commonly referred to the living

genus Dammara, leafy branches commonly referred to the extinct

Coniferous genus Brachyphyllum, whose exact botanical affinities

have not heretofore been satisfactorily determined, and certain

lignitic fragments found associated with the foregoing.

The first mentioned are shown to belong not to Dammara but

to an extinct genus, closely related to it, to which the new generic

name Protodammara is given. The second are shown to be

Araucarinean in their affinities and probably to represent the

branches of the tree which bore the cones from which the scales

of Protodammara were derived. 'The third are shown to be

referable to Araucarioxylon and probably to represent the wood

of the tree which bore the leaves of Brachyphyllum and the cones

of Protodammara.

! Read before the Botanical Society of America, New Orleans meeting,

January 4, 1906.

Contributions from the Phanerogamie Laboratories of Harvard University.

0. 4.

Contributions from the New York Botanical Garden.— No. 79.

189

190 THE AMERICAN NATURALIST [Vor. XL

DISCOVERIES WHICH SUGGESTED THE PREPARATION OF THIS

PAPER

The discoveries which suggested the preparation of this paper

were described in a previous paper read before the Botanical

Society of America at the Philadelphia meeting, on December

30th, 1904. During the autumn of that year an interesting

section of Cretaceous deposits was found exposed in the Andro-

vette clay pit, at Kreischerville, Staten Island, N. Y. At this

locality the deposits consist of irregularly stratified sands and

clays, in one part of which occurs a lens-shaped bed of closely

packed vegetable débris, consisting of leaves, cone scales, twigs,

amber, charred wood, and lignite. At that time special attention

was given to the amber and the other remains were merely exam-

ined superficially and briefly mentioned. ‘The suggestion was

made by Dr. Jeffrey that critical examination of the lignitic frag-

ments would probably produce interesting results, and this sug-

gestion led to two joint visits to Kreischerville during the past

year and the collection of a large amount of new material, in part

from the original locality and the remainder from the nearby

Drummond pit. Some of the results obtained from the exami-

nation of this material form the basis of this contribution.

OBJECT AND SCOPE OF THE INVESTIGATION

One of the great difficulties in connection with any attempt to

determine satisfactorily the relationships of paleobotanical speci-

mens is due to the fact that such specimens are nearly always

more or less fragmentary, being represented only by dismembered

parts or organs of plants, and seldom or never by a complete

individual organism. Under such conditions it is not surprising

that descriptions based upon superficial characters only have fre-

quently resulted in erroneous generic determinations; different

parts of the same species have often been described under two or

more specific or generic names; or occasionally a single specific

1 Arthur Hollick. “The Occurrence and Origin of Amber in the Eastern

United States.” Published in Amer. Nat., vol. 29, pp. 137-145, pls. 1-3, 1905.

No. 471] CRETACEOUS PLANT REMAINS 191

name was made to include several different fragments which were

subsequently ascertained to belong to two or more distinct species.

The identification or determination of a genus solely from the

shape or superficial markings of a cone or some of its detached

scales or of a leaf or a leafy twig, can seldom be entirely conclusive

or satisfactory; but it may be readily appreciated that if, in addi-

tion, the internal structure of such specimens can be made out by

the use of the microscope, not only may the genera be thus deter-

mined beyond question, but many fragmentary scattered remains,

presenting no superficial characters of any diagnostic value, might

thus be identified and brought together into their true generic and

specific relationships.

Superficial examination of the Kreischerville material showed

that it contained a number of recognized species, descriptions of

which were based upon well defined external characters, besides

quantities of specimens which were not identifiable: by ordinary

means. This indicated a specially favorable field for investiga-

tion, of which advantage was taken, and the methods employed,

together with some of the selected results obtained, are here de-

scribed.

DESCRIPTION OF THE GROSS MATERIAL

Botanical Characters of the Plant Remains.— A rough exam-

ination of the gross material showed the presence of pteridophytes,

angiosperms, and gymnosperms. The remains of the pterido-

phytes were exceedingly fragmentary and unsatisfactory. Those

of the angiosperms consisted for the most part of dicotyledonous

leaf impressions in the clay, usually accompanied by a thin film

of carbonaceous matter, which generally disappeared on exposure

to the air.

The remains of the gymnosperms proved to be more satisfactory,

however, being represented not only by isolated coniferous leaves

which retained more or less of the substance of the plant, but also

by leafy twigs and branches, cones and cone scales, and fragments

and logs of lignite, some of which contained amber in their inter-

stices. Special attention was therefore given to these remains

amongst which specimens of the following genera and species

were separated out and identified.

192 THE AMERICAN NATURALIST [Vor. XL

List of the Coniferous Remains

1. Cone scales, allied to Dammara and similar to very small speci-

mens of D. microlepis Heer. These are described in this paper on p. 199

under the new generic name Protodammara.

2. Cone scales and leaves of Pinus sp. The scales are relatively

small. Several of the leaf specimens showed three in a bundle, enclosed

in a sheath.

3. Leafy twigs of Sequoia reichenbachi (Gein.) Heer, S. heterophylla

Vel., Juniperus hypnoides Heer, Widdringtonites reichit (Etts. Heer,

F Hineopetd gracilis Newb., and Brachyphyllum macrocarpum Newb.

4. Lignite and other‘ MISERIS coniferous remains which could

not be generically determined from their external characters.

mber, occasionally in the interstices of the lignites, but for the

most part in the form of small drops or “tears” and irregular fragments.

METHODS EMPLOYED IN THE CRITICAL EXAMINATION OF THE

MATERIAL

Maceration and Separation of the Gross Material.—In the

examination of the finer vegetable débris previously described

the following method was employed. Caustic soda or potash

in 1 to 3% solution was used with considerable success. After

this treatment the fragments of plants were somewhat swollen

and separated readily from one another and from the argillaceous

matrix. The loosened clay was washed away on a wire gauze

tray of not too fine meshwork and the lignitic or carbonaceous

fragments were left in a clean and recognizable condition. ‘The

fragments in most cases were rather small, especially those of

greatest interest, so that the most convenient method of recogni-

tion was by means of a dissecting microscope of very low magni-

fication. A great many different kinds of coniferous remains

were thus separated out and identified from their external appear-

ance, as well as many charred specimens of dicotyledonous woods.

Of these in general no account will be given at the present time,

for attention was restricted to the cone scales similar to those

referred by Heer to the genus Dammara, leafy branches belonging

to the Brongniartian genus Brachyphyllum, and certain Ar-

aucarineous lignites. ‘The chosen material was often in a very

No. 471] CRETACEOUS PLANT REMAINS 193

good state of preservation especially when charred, or partially

charred.

Sectioning and Microscopic Examination of Specimens.— In

the case of lignitic or charred vegetable remains it is necessary

for successful study to obtain very thin sections, on account of the

dark color and opacity of the fossilized tissues. By the use of

hydrofluoric acid for removing mineral matter and by embedding

in thickened celloidin, it was found possible to make sections

often of large area, as thin as 5 micra which proved admirable

for photomicrographic purposes. These sections were cleared

at once in benzole without previous staining, since the natural

dark color of the lignites was sufficiently pronounced to differ-

entiate the structures, even in very thin sections. In some cases

it was found necessary to reduce the natural dark hue of the prepa-

rations and chlorine water was useful for this purpose. The

sections were mounted in balsam on plate-glass slides and after

previous drying were subjected to pressure and high temperature

in the warm oven for the purpose of making them perfectly flat.

All the photomicrographs in the present article were made by

means of Zeiss lenses, except those showing surface features.

The latter were executed with the admirable Heliar lenses of the

Spencer Lens Co. Electric light was employed in all cases as the

illuminant. :

DESCRIPTIONS OF SPECIMENS

Cone Scales Commonly Referred to Dammara. — Fossil cone

scales similar to ours were described and figured for the first time

by Professor Edward Hitchcock, in his account of the organic

remains found at Gay Head, Martha’s Vineyard. ‘They were not

named by him, but his figures and description leave little to be

desired. He says: “Figs. 4, and 5, represent different individuals

of another variety of vegetable remains... .These are not mere

impressions; but a scale of carbonaceous matter, mixed with

amber, marks the spot where the vegetable was imprisoned. . . . It

seems to me very obvious that these remains must be the seed

vessels of some coniferous plants."

! Final Rept. Geol. Mass., vol. 2, p. 430, pl. 19, figs. 4, 5, 1841.

194 THE AMERICAN NATURALIST [Vor. XL

It was not until many years after Hitchcock’s description was

published that any further discovery of similar remains was made,

or at least recorded, and to Professor Oswald Heer belongs the

credit of first recognizing their affinities with the living Coniferous

genus Dammara, in his description of specimens identical with

those from Gay Head, under the name D. borealis; from the

Cretaceous of Greenland, in his discussion of which he says (p. 55):

“Es haben diese Schuppen so grosse Aehnlichkeit mit derjenigen

von Dammara (Agathis), dass wir sie derselben Gattung zutheil-

en dürfen." For purposes of comparison a figure of this species,

representing a specimen collected at Gay Head, is shown on Plate

1, Fig. 1

Two other so called species were also described and figured

by the same author, viz.: D. microlepis? and D. macrosperma.’

A specimen of the former, collected at the Gay Head locality, is

shown on Plate 1, Fig. 2, which, by comparison, may be seen to

differ from D. borealis merely in size. D. macrosperma has not

been recognized in any collection of material except that from

Greenland, and it is doubtful if it should be regarded as speci-

fically distinct from the other two. In other words all three of

these so called species might very well be included under D.

borealis.

Heer was evidently in considerable doubt in regard to the

identity of some of his specimens and also with regard to their

botanical relationships. In his discussion of D. microlepis for

example he says (p. 55, loc. eit.): “Hat einige Aehnlichkeit mit

den Blüthenknospen des Eucalyptus Geinitzi," and a comparison

with the figures of the objects which he refers to the fruit of that

species * shows them to be so closely similar in appearance to his

Dammara scales as to be practically indistinguishable from them.

Krasser, Beyer, and Velenovsky subsequently described and

figured similar remains from the Cretaceous of Europe, with vary-

ing opinions as to their probable botanical affinities. The last

! Fl. Foss. Arct., vol. 6, pt- 2, p. 54, pl. 37, fig. 5, 1882,

? Ibid., p. 55, pl. 40, fig. 5

5 Ibid., vol. 7, p. 17, pl 45, fg. i1, 1883.

* Ibid., vol. 6, pt. 2, p. 93, pl. 45, figs. 4-9, 1882,

No. 471] CRETACEOUS PLANT REMAINS 195

author first referred them to Eucalyptus geinitzi Heer, with the

leaves of which species they were found closely associated, but

later he called what are evidently identical remains Dammara

borealis Heer.”

In 1889, Mr. David White visited Gay Head, and in the fol-

lowing year, in a paper “On Cretaceous Plants from Martha's

Vineyard"? he described and figured specimens collected there,

referring to them as follows (pp. 98, 99): “Next to the preceding

species, the most numerous of the plants from Gay Head is

Eucalyptus Geinitzi Hr., fig. 8-11, two of whose fruits, ‘ resem-

bling unopened flowers of syngenesian plants,’ were figured as

‘scales of vegetable remains’ in Hitchcock’s Final Report. This

species, first described from the Liriodendron beds (Middle Cre-

taceous) of Greenland, is abundant in and most characteristic of

the Middle Cretaceous of Bohemia, and is also present in the

same stage (Cenomanian) in Moravia. The specimen, fig. 11,

is included here on account of its coincidence with one figured by

Velenovsky (Foss. Flor. bóhm. Kreide., iv, pl. xxv, fig. 7), which

he supposed represented a flower of this species. It may belong

to a conifer.

“ The remains of the nuts show longitudinal furrows (white in

the figures) filled with a resin which is 'indistinguishable by

ordinary tests from Amber, and which was observed and pro-

nounced amber by Hitchcock in 1841. These doubtless are the

remains of gum or oil vessels, such as exist in the nuts of recent

Eucalypts; and the granules of *amber can hardly be else than

Eucalyptus gum.

“ The explanation is at once suggested that the fragments of

amber observed by various writers, during the last hundred years,

about Gay Head, and in the New Jersey Cretaceous, where also

Eucalypts are found, are the product of the contemporaneous

'gum-trees, rather than of some conifer. None of this Ameri-

can amber has, I believe, been tested for succinic acid, or to

show its relation to true amber."

! Foss. Fl. Böhm. Kreidejorm., pt. 4, p. 1 [62], pl. 1 [24], figs. 1, 2; pl. 2

[95], figs. Sup pl. 4 [27], fig. 13 in part, 1885

* Kvet. Cesk. Cenomanu, p. 7, pl. 1, figs. 28, 29, 1889.

! Amer. AGE Sci., vol. 39, p. 93-101, pl. 2, 1890.

196 THE AMERICAN NATURALIST [Vor. XL

At about this same time Dr. J. S. Newberry was engaged in the

investigation of the Cretaceous flora of New Jersey, the results of

which were later included in his “Flora of the Amboy Clays.” *

In this work he lists Dammara borealis Heer as a characteristic

and abundant element of the flora, and says (pp. 46, 47): “In his

Flora Fossilis Arctica (loc. cit.) Professor Heer describes and fig-

ures the scales of a conifer which very much resemble those of

Dammara australis, and yet there are some reasons for doubting

the accuracy of his reference. It may also be said that the fruit

scales which he calls Eucalyptus Geinitzi....are without doubt

generically the same.... the fruits figured by Heer under the

name of Eucalyptus are plainly scales, and are parts of an imbri-

cated cone. I say this with confidence, because it has happened

that in the Amboy clays we have found numbers of them some-

times associated together, oftener scattered and showing both faces.

A peculiarity of these scales is that they are striped longitudinally

by clefts which are filled with an amber-like substance. This

structure is plainly seen in those figured by Professor Heer on Pl.

XLV. Similar scales are described in an article by Mr. David

White on the fossil plants from Gay Head....

“The considerations which have led me to doubt whether these

cone scales are those of Dammara are that we have found no

Dammara-like leaves associated with them, whereas in New

Jersey they occur in great numbers mingled with and sometimes

apparently attached to the branchlets of an extremely delicate

conifer much like Heer’s Juniperus macilenta.... Almost no

other plant except this conifer is found with the cone scales, and

it is difficult to avoid the conclusion that they belong together.

Another reason for doubting whether these are the scales of a

Dammara is that in some of them traces of two seeds are appar-

ently visible, while in Dammara there is but one seed under each

scale.”

The discussion is further continued by Dr. Newberry under his

1 Monogr. U. S. Geol. Surv., vol. 26, 1895.

2 This observation by Dr. Newberry is particularly interesting in the light

of what we now know in regard to the Kreischerville specimens, as may be

appreciated by referring to our description of the seed scars on those scales,

on p. 199.

No. 471] CRETACEOUS PLANT REMAINS 197

description of Juniperus macilenta, on pp. 54, 55 (loc. eit.), as fol-

lows: “ Thickly scattered among the twigs there are cone scales

and cones.... The cone scales are evidently identical with those

described by Heer under the name of Dammara microlepis....

and probably with those described by him as Dammara borealis.”

He says, however, that they cannot belong either to Dammara

or to Juniperus and finally concludes with the hope “that in the

future material will be obtained that will enable us to reconstruct

this tree and determine with accuracy its botanical relations.”

Dr. Newberry again refers to the scales in connection with his

discussion of Eucalyptus ? angustifolia, in the following words

(ibid., p. 111): “Professor Heer feels strengthened in his refer-

ence of leaves having this nervation to Eucalyptus by finding in

company with them what he regards as the fruit of Eucalyptus;

but in my judgment the examples he gives of this fruit. ...are

rather detached scales of the cone of some conifer, and probably

generically identical with the cone scales which he has called

Dammara borealis."

Some years ago the senior writer of this.paper began an investi-

gation of the Cretaceous flora of the Atlantic coastal plain, and in

the material collected in New Jersey and on Staten Island, Long

Island, Block Island, and Martha's Vineyard, numerous speci-

mens of cone scales were found, some of them unquestionably

identical with Dammara borealis or D. microlepis as defined by

Heer, and others which apparently represented new species.

Following are references to the specimens in question:—

" Dammara borealis, Heer?" Tottenville, Staten Island. Trans.

N. Y. Acad. Sci., vol. 12, p. 31, pl. 1, fig. 17, 1892.

"Dammara borealis, Heer." Chappaquidick, Martha’s Vine-

yard. Bull. N. Y. Bot. Gard., vol. 2, p. 402, pl. 41, fig. 6, 1902.

" Dammara microlepis Heer (?).” Ball’s Point, Block Island.

Ann. N. Y. Acad. Sci., vol. 11, p. 57, pl. 3, figs. 9 a, b, 1898. At

the time when these two specimens were described they were only

referred provisionally to this species, in the following words: “The

ones under consideration are, however, smaller than any which .

have been previously figured and might perhaps be referred to a

new species, but in view of the limited amount of material and its

fragmentary condition, I have thought it best to refer the speci-

198 THE AMERICAN NATURALIST [Vor. XL

mens provisionally to Heer's species." I am now satisfied that

they belong to the new genus and species hereafter described and

they are included, for comparison, on Plate 1, Figs. 12, 13.

* Dammara Northportensis sp. nov." Little Neck, Northport

Harbor, Long Island. Bull. N. Y. Bot. Gard., vol. 3, p. 405, pl.

70, figs. 1, 2, 1904. A figure of this species is reproduced on Plate

1, Fig. 4.

“Dammara (?) Cliffwoodensis n. sp.” Cliffwood, N. J. Trans.

N. Y. Acad. Sci., vol. 16, p. 128, pl. 11, figs. 5-8, 1897. A figure

of the type specimen of this species is reproduced on Plate 1, Fig. 3.

This species may also be found described and figured by Mr.

Edward W. Berry in his “Flora of the Matawan Formation (Cross-

wick’s Clays)," * and again in a subsequent paper on ** Additions

to the Flora of the Matawan Formation";? but the figures more

nearly resemble D. borealis than they do the species to which they

are referred, and the author himself remarks, in regard to the one

last mentioned (p. 70): “The specimen is an unusually perfect

one.... In outline and size it is very similar to the scale from

Tottenville referred by.Hollick to Dammara borealis Heer.”

Finally may be mentioned the species described and figured by

Dr. F. H. Knowlton, under the name Dammara acicularis, in his

“Fossil Plants of the Judith River Beds," * which differs from all

the other species in the possession of a well defined apical awn or

spine, although in many of our individual specimens a similar

feature, of smaller size, is present, and in others its former pres-

ence is clearly indicated.

If all the opinions expressed by the authors in the papers quoted,

are analyzed it may be seen that a majority favor the idea that the

scales are Coniferous and that their relationships are with Dam-

mara, or with some other genus closely allied to it. Whether

more than one species is represented in the various forms that

have been described as such is a problem which yet remains to be

solved and its solution will doubtless be attended with more or

less difficulty, but the identification of the genus to which each

form belongs should be a comparatively easy task, provided the

1 Bull. N. Y. Bot. Gard., vol. 3, p. 61, pl. 48, figs. 8-11, 1903.

? Bull. Torrey Bot. Club, vol. 31, p. 69, pl. 1, fig. 11, 1904.

3 Bull. U. S. Geol. Surv., no. 257, p. 134, pl. 15, figs. 2-5, 1905.

No. 471] CRETACEOUS PLANT REMAINS 199

material available for study is such that it can be sectioned and

subjected to critical examination under the microscope. Thus

far the only specimens which we have so examined are those from

Kreischerville, but it is hoped that the investigation may be con-

tinued in the future so as to include specimens from other localities.

Protodammara speciosa n. gen. et sp.

Plate 1, Figs. 5-13; Plate 2, Figs. 1-5

““ Dammara microlepis Heer (?)." Hollick, Ann. N. Y. Acad. Sci., vol.

11, p. 57, pl. 3, figs. 9 a, b, 1898.

Organisms consisting of kite-shaped cone scales, from 4 to 6 mm.

long by 4 to 6 mm. broad above, abruptly narrowed from about the

middle to the base, rounded, incurved, and apiculate above; resin

ducts five or more, extending down the lower surface of the limb;

seed scars three in number, crescentically arranged above the middle

and approximately in the broadest part of the scale, with the central

one higher up than the laterals.

Plate 1, Figs. 5-13, shows the scales natural size; Plate 2, Figs.

1 a, b, e, 2, shows four specimens with the upper surfaces exposed,

magnified about ten diameters. Although they may be seen to

resemble closely those of a small female cone of Dammara they

are distinguished from the scales of that genus by the apical proc-

ess and by the fact that they obviously bore three seeds instead

of only one. It might indeed be inferred, from the presence of

three apically attached ovules, that we have here to do with cone

scales of one of the Sequoiineze, rather than with one of the Arau-

carinex, but the internal structure shows that they are truly

Araucarian.

Plate 2, Fig. 3, represents a transverse section of the base of a

scale, magnified about 40 times. A little below the middle point

may be seen a single small fibrovascular bundle. At a higher

plane of section this separates off a single upper bundle of inverted

orientation and gives off a number of lateral bundles to the lower

surface of the scale. The upper bundle supplies the seeds. In

the higher part of the scale the inferior bundles are surrounded

200 THE AMERICAN NATURALIST [Vor. XL

by a dense cordon of transfusion tissue. The arrangement of

the bundles of the scale presents throughout a close resemblance

to that found in Dammara.

Plate 2, Fig. 4, represents about half of a transverse section of

a scale, magnified about 50 times. The funicular attachment of

one of the lateral seeds may be seen on the upper surface of the

scale.

Plate 2, Fig. 5, shows a longitudinal section through the apex of

the scale, which at the same time is also nearly median, magnified

about 40 times.

There can be no doubt that these scales are Araucarian and that

while they resemble the genus Dammara they do not belong to it.

We have therefore proposed for them the generic appellation

Protodammara.

Formation and Locality: Cretaceous clays, Raritan Formation.

Pl. 1, Figs. 5-11 and Pl. 2, F igs. 1 a, b, c, 2, Kreischerville, Staten

Island, N. Y.; Pl. 1, Figs. 12, 13, Ball's Point, Block Island,

R. I.

Leafy Branches Commonly Referred to Brachyphyllum.— This

genus was based upon the external characters of certain leafy

branches, of Jurassic age, and was described under the noncom-

mittal heading “Conifere douteuse.” The type of the genus is

B. mamillare Brongt., which he described but did not figure.

The species was figured by subsequent authorities however, not-

ably by Saporta, one of whose illustrations (fig. 4, loc. eit.), is

reproduced on Plate 1, Fig. 14. A number of other species have

also been described under the genus and under the closely related

or synonymous genera Echinostrobus, Arthrotaxites, Thuites,

Palseocyparis, ete. By some authors these genera have been all

included under Brachyphyllum and by others they have either

been regarded as distinct:or else they have been grouped in various

combinations. Their true botanical relationships, however, were

never satisfactorily determined, although they were generally con-

sidered as allied to the Sequoiine or the Cupressinee and as

related to Arthrotaxis, Thuja, or Glyptostrobus. The species

! Prod. Hist. Veg. Foss., p. 109, 1

? Plantes Jurassiques, vil 3, pl. "Yn am. 3-7, 1884.

No. 471] CRETACEOUS PLANT REMAINS 201

described by the earlier authors were all from Jurassie horizons

but subsequently species were described from the Cretaceous,'

and it is with these that we are especially concerned.

The question of generic identity between the several allied

forms does not, however, come within the scope of this paper.

The only matter which is of immediate concern is the fact that

we have found at Kreischerville the leafy branches of a Brachy-

phyllum and have been able to determine, for the first time, by

means of its internal structure, the exact relationship which it

bears to certain living Coniferz. This species is the same so far

as external characters are concerned, as that described by New-

berry from the Amboy clays of New Jersey (B. macrocarpum

Newb., loc. cit.), and it has also been found at Northport,

Long Island, and at Cliffwood, N. J. A reproduction of New-

berry’s fig. 1 (Joc. cit.) is shown on Plate 1, Fig. 15, and the North-

port specimens on the same plate, Figs. 16, 17. These are all

natural size.

Plate 3, Figs. 1 a, b, c, shows three fragments of branches from

Kreischerville, magnified about 6 times, and Fig. 2, on the same

plate, shows one magnified about 10 times.

Plate 3, Fig. 3, shows a piece of another branch magnified about

the same as the latter, and illustrates particularly well the longi-

tudinal converging strise characteristic of the leaves of Brachy-

phyllum.

Plate 3, Fig. 4, represents a transverse section through a rela-

tively old branch, magnified by 8, in which the woody cylinder is

well developed. The pith has largely collapsed, although it con-

sists in large part of sclerotic cells.

Plate 3, Fig. 5, shows a transverse section of a young branch,

magnified by 15. Four leaves may be seen on the margins of the

figure, and of these, those on the broad upper and lower surfaces

of the branch overlap those on the margins, as they are cut through

at a higher region. ‘The leaves are attached to the surface of the

stem by practically all of their ventral surface, with only a very

! Echinostrobus squamosus Vel., Gymnosp. Böhm. Kreideform., p. 16, pl. 6,

figs. 3, 6-8, 1885; Thuites crassus Lesq., Cret. and Tert. Fl., p. 32, 1883; Brachy-

Phyllum macrocarpum Newb., “ Fl. Amboy Clays” (Monogr. U. S. Geol. Surv.,

vol. 26), p. 51, footnote, pl. 7, figs. 1, 2, 5, 7, 1895.

202 THE AMERICAN NATURALIST [Vor. XL

narrow border left free, where in their upper portions they over-

lap their neighbors. The anatomical features cannot be made

out in this section as the magnification is not sufficient.

Plate 4, Fig. 1, shows a transverse section through the woody

cylinder of the younger branch shown on Plate 3, Fig. 5. By

using a lens it may be seen that at this stage the cylinder consists

of clearly separated bundles. On the right a single leaf-trace is

passing off.

Plate 4, Fig. 2, reproduces a cross section of the basal portion

of a leaf from the margin of the same young branch. It may be

seen that there are several fibrovascular bundles present. ‘These

have originated from the single trace previously described. Of

the Cupressinez, Sequoiinez, and Araucarinex, the only Conifers

with which Brachyphyllum has ever been placed, the latter group

alone have the branched leaj-trace.

Plate 4, Fig. 3, shows a similarly branching leaf-trace from one

of the broad leaves which clothe the upper and lower surfaces of

the stem in the genus Brachyphyllum.

Plate 4, Fig. 4, shows a portion of the latter under a higher

degree of magnification. The lower fibrovascular tissue is obvi-

ously dividing into three branches.

Plate 4, Fig. 5, is part of a branch of Brachyphyllum in trans-

verse section. The light spaces are the sections of resin-canals.

Although the material was passed through a number of solvents

of resin, used in a hot condition, there is still some matter present

in the lumina of the resin-passages. This appears to be of a

mucilaginous nature and is comparable to that found among living

Conifers only in the genera Araucaria and Dammara.

Plate 4, Fig. 6, shows a transverse section of a diseased branch

of Brachyphyllum, in which there is one particularly large resin-

cavity. The fossil mucilage, as we consider it to be, is present

also in this instance. We have, in fact, found this substance to

be always present in Brachyphyllum, except in charred branches,

and those which had become very rotten in the process of fossili-

zation. The mucilaginous contents of the resin-canals afford an-

other reason for associating Brachyphyllum with the Araucarinee

rather than with the Cupressinee or the Sequoiinee.

The most important argument, however, in favor of the Arau-

No. 471] CRETACEOUS PLANT REMAINS 203

carineous nature of Brachyphyllum is the structure of the wood

and phloém. Plate 5, Fig. 1, is a longitudinal radial section of the

tracheids of the wood, highly magnified. They show the flattened

and alternating bordered pits, which are the diagnostic feature of

Araucarioxylon Kraus.

Plate 5, Fig. 2, makes the diagnosis beyond dispute, as it shows

the very striking Araucarineous character of the rays. Plate 5,

Fig. 3, represents a transverse section through the xylem and

phloém in a yearling branch. Plate 5, Fig. 4, shows two bundles

in the young stem of Brachyphyllum. It may be seen that the

region of the phloém is marked by the absence of the regularly

alternating rows of hard bast-fibers, which are found without

exception in the phloém of all Cupressineous and Sequoiineous

Conifers.

Lignites Rejerable to Araucarioxylon.— Associated with the cone

scales of Protodammara and with the leafy branches of Brachy-

phyllum are found numerous specimens of lignite, amongst which

are two types of Araucarioxylon. The first of these is very simi-

lar to the wood of the living Dammara, and like Dammara it is

characterized by the presence of resinous tracheids. ‘The pith,

when present, is seen to be large and composed mainly of tanni-

niferous cells as in that genus. When wounded the wood of this

Araucarioxylon does not give rise to traumatic resin-canals.

The second type, so far as we have been able to observe, does

not possess resinous tracheids. ‘The pith, when present, is sclerified

and of small size as in Brachyphyllum. The wood, when injured,

forms resin-canals of a traumatic character.

Plate 5, Fig. 5, shows a row of traumatic resin-canals in this spe-

cies. Plate 5, Fig. 6, shows one of these resin-canals and the ad-

jacent wood, highly magnified. The tracheids of the wood are seen

to be free from resin. This type of Araucarioxylon appears to be

the wood of Brachyphyllum, while the type first described appears

to belong to Araucarian Conifers more nearly allied in structure

to those now in existence.

204 THE AMERICAN NATURALIST [Voi XL

CONCLUSIONS

The cone-scales referred by Heer to Dammara, at least in the

case of those from Kreischerville, do not belong to that genus but

to the hitherto unrecognized Araucarinean genus Protodammara.

The leafy shoots and branches from several eastern American

Cretaceous beds referred by various authors to Brachyphyllum'

are of Araucarian affinities, as shown by their structure and as

indicated by their constant association with the cone scales of

Protodammara.

A large part of the lignites associated with both the above are

Araucarineous and probably represent in part the wood of the

trees which bore the leafy branches of Brachyphyllum and the

cones of Protodammara.

The latter genus was in all probability the last survivor of an

ancient Araucarian line of descent, joined near its base with the

primitive stocks of the Abietineous and Cupressineous series. Its

anatomical characters show that it was forced to occupy less

advantageous situations in Cretaceous times, and possibly in

earlier periods as well. It may have grown on dry hills, while

the better adapted related forms, which still survive in the modern

genera Araucaria and Dammara, flourished in the richer lowlands,

in company with other gymnosperms of higher type of develop-

ment and with the angiosperms, which even then had begun to

assume the predominant position which they occupy to-day.

1 We do not consider it by any means proved, that all the leafy branches

of the type of Brachyphyllum are necessarily Araucarian. It appears not

improbable that some of the shoots of this general type may belong to

other families of the Conifers. This for example may well be the case with

some Coniferous remains recently described by M. Zeiller, from the upper

Lias of Madagascar and referred to Sequoiineous affinities. In this instance

the cones were found attached to the branches and the author remarks that

the superior portion of the cone scale terminates “en une pointe obtuse-

ment aigue”, a somewhat suspicious feature of resemblance to our Pro-

todammara.

PLATE 1

Fig. 1.— Dammara borealis Heer, natural size. Gay Head, Martha’s Vineyard,

Fic. 2.— Dammara microlepis Heer, natural size. Gay Head, Martha’s Vineyard,

Fic. 3.— Dammara cliffwoodensis Hollick, natural size. Cliffwood, N. J.

Fic. 4.— Dam a northportensis Hollick, natural size. Little ck Northport

Harbor, Long Island, N. Y.

Figs. 5 gen. et sp atural size. Figs. 5-11, Krei-

5-13.—

ee — Island, N. Yi Figo. 12, 13 a has Point, Block Island, R. I.

en BR ds tuas hyllum mamillare ae (after r Saporta), natural size.

Fic. h ural size. South Amboy, N. J.

ne 16, 17.— Daas llum ss eniti Mot. natural size. Little Neck,

orthport Harbor, Long Island, N. Y.

PLATE 2

Pr otodammara speciosa n. gen. et sp., enlarged. ^ Kreischerville,

Fig. 4.— About half of a transverse section of a s

Fig. 5.— send grim section ehr the apex ota a soa x 40.

Figs, 1-5.—

Staten Island, N.

Figs. 1 a, b, c, er surface of cone scales, x 10, or more.

Fig. 3.— Transverse —— va ae base of à "egi E ntes 40.

PLATE 4

Fics. 1-6.— Brachyphyllum ‘macrocarpum Newb. enlarged. Kreischerville,

Staten Island, N. Y.

Fig. Transverse en through the young woody cylinder of the branch

shown on Plate 3, Fig.

Fig. ort pgs section = the basal portion of a leaf from the margin of the

same,

Fig. Ee Ped ars a wd leaf trace, x 50.

Fig. 4.— uie highly ed,

Fig. 5.— Transverse ‘section of a branche showing resin-canals, x 30.

Fig. 6.— et ze of a diseased branch, ee a rohr

large resin-canal,

212

PLATE 5

Fios. 1-4 Mee aa macrocarpum Newb., enlarged. Kreischerville,

ada Island, N. ;

Fig. 1.— era radial section showing the radial pits of the tracheids,

x 200.

Fie. 2.— — LM showing the characteristic Araucarian lateral pits of

the ray cells,

Fig. 3.— Td section of the xylem and phloém in a yearling branch,

x 200.

Mer „4.— Transverse section of a young branch showing the xylem and

m, x 200.

ha Pa ge re sp., enlarged. Kreischerville, Staten Island, N. Y.

section of injured wood,

Fig. i One of the traumatic resin canals of the same, x 150.

214

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A NEW PYCNOGONID FROM THE BAHAMAS

LEON J. COLE

Mr. Thomas Barbour has kindly turned over to me for exam-

ination a single pycnogonid taken upon the expedition made by

himself, in company with Dr. G. M. Allen and Mr. Owen Bryant,

to the Bahama Islands in the summer of 1904. A general narrative

of their cruise has been published privately by Allen and Barbour

(:04) The present paper constitutes the seventh of a series based

upon the specimens collected by them.

It would appear from the fact that only a single pycnogonid

was taken during this trip, and that none has been reported from

the collections of previous scientific expeditions to the same region,

that this group must be poorly represented in the waters contiguous

to the Bahamas. And in this connection it is interesting to note

that the specimen under consideration belongs without doubt, in

its systematic relationships, with two species which Dohrn (81)

described from the Gulf of Naples, constituting his genus Barana.

This genus is undoubtedly very close to Parazetes, established by

Slater (79) for a pyenogonid from Japan, and possibly should be

united with it. The chief difference appears to be the possession

by Parazetes of only 9 joints in the palpi, but this is of the less

importance when one considers that it is apparently the terminal

joint which is lacking, and that the other joints have about the

same relative proportions that they have in Barana. Slater lays

emphasis on the point that in his specimen the proboscis was

4-cleft; but since the trimerous proboscis is almost universal *

in all other known Pyenogonida, it is not unreasonable to suppose

that he might have had a specimen possessing an individual

abnormality. Unfortunately he gives no figures, which would

greatly have facilitated the comparison of Parazetes with other

‘In Rhynchothorax mediterraneus O. Costa the proboscis is said to consist of

but two antimeres, owing to the failure of the dorsal antimere to develop (cf.

Dohrn, '81, p. 211).

217

218 THE AMERICAN NATURALIST Vorn XL

pyenogonids. Should later discoveries show these forms to belong

properly in the same genus, the name Parazetes will take pre-

cedence over Barana.

‘As Sars (’91, p. 133) remarks, the genus Ascorhynchus is cer-

tainly very close to Barana, but Eurycyde appears to be well

characterized. It seems to me doubtful that Nymphopsis * Has-

well (’85) and Aleinous O. Costa (’61) belong in this family (Eury-

cydidee).

Barana latipes sp. nov.

Pl. 1, Figs. 1-4; Pl. 2, Figs. 5-11 a

Type: Adult 2, Museum of Comparative Zoólogy, no. 6947,

Crustacea. Collected by Owen Bryant, from rocky shore, Sweet-

ing's Village, Great Abaco, Bahamas, 22 July, 1904.

'Trunk broad, compact, tapering somewhat posteriorly; seg-

mentation well marked, the first three segments conspicuously

enlarged dorsally and ventrally at their posterior ends, this en-

largement forming almost a knob on the dorsal side. Lateral

processes stout, about as broad as long, closely approximated but

without touching, and each with a conical protuberance dorsally

near its distal end. First trunk segment extending anteriorly

from the eye tubercle in an elongate, cylindrical neck, which has

distinct processes for the articulation of the palpi and the ovigera,

the former at the anterior end, the latter immediately anterior to _

the processes of the first legs. ‘The neck is prolonged at its ante-

rior end into two sharp conical processes, beneath which the

chelifori arise. Trunk and all its processes almost smooth and

unarmed.

Caudal segment (Pl. 2, Fig. 7) elongate, horizontal, enlarged

distally, and sparsely armed with a few scattered small spines;

about as long as neck anterior to the processes for the ovigera.

Eye tubercle situated at the base of the neck and midway in

the length of the first trunk segment; rather high and pointed

forward; consisting of a smaller pointed dome placed on the ante-

rior face of a larger conical elevation (see Pl. 1, Fig. 2). Eyes

dark; in the smaller dome.

‘More fully characterized by Schimkewitsch ('87, p. 128).

No. 471] ` NEW BAHAMA PYCNOGONID 219

Proboscis large, trimerous, with three distinct lips at the tip

(Pl. 2, Fig. 6); it arises from the ventral side of the neck at its

anterior end, and is directed downwards and backwards, in which

position it reaches back to the posterior border of the second

trunk segment (see Pl. 1, Fig. 2). In outline it is seen to be

fusiform, but is divided at about its distal third by a distinct

groove; the basal part does not, however, constitute a distinct

segment as in Eurycyde. The proximal portion expands rather

regularly to its outer end, while the distal portion taken by itself

is distinctly pear-shaped. In cross section, or as viewed from the

‚end (Pl. 2, Fig. 6), the proboscis is triangular, the dorsal angle

being directed downward as the organ is carried turned back

under the body. !

Chelifori (Pl. 1, Fig. 3) short, 2-jointed,' and armed with a

few small, scattered spines. The basal joint, which expands

somewhat distally, is only about as long as the breadth of one

of the lateral processes, while the second joint is merely a minute

rounded knob. No indication could be seen of a former chelate

condition, though these organs undoubtedly possess chelz in the

arva.

Palpi (Pl. 2, Fig. 11) arising from small lateral processes at

the anterior end of the neck; 10-jointed; joints 1 and 2 very

short; joints 3 and 5 about equal in length, and much the long-

est of all; the former expands rather gradually distally, while the

latter is broadest near its proximal end. Joint 4 equals in length

about one third of joint 5; joint 6 is still shorter and bends at a

right angle to 5; joint 7 is slightly longer than joint 6, and the

succeeding joints, 8, 9, and 10, decrease gradually in size. ‘These

distal four joints normally lie in nearly a straight line and par-

allel with joint 5, and reach back about two thirds of its length.

The first five joints are sparsely armed with small spines, which

become more numerous, however, at the distal end of joint 5,

‘Carpenter (: 05, p. 4) maintains with good reason that each of the parts of

the chela, when present, should be counted as a joint. Without explanation,

however, such a nomenclature is apt to introduce confusion, especially in those

cases where the movable finger is reduced to the merest knob or projection on

the palm, or may apparently disappear completely, as in the case of the species

here described.

220 THE AMERICAN NATURALIST [Vor. XL

and are thickly set on the outer sides of all the succeeding joints,

where they are about equal in length to the diameter of the joints.

The whole palp, if extended straight backward, would reach

about to the base of the caudal segment.

Ovigera (Pl. 2, Fig. 9) 11-jointed;! about a third longer (in

the female) than the palp, the length to the principal flexure, be-

tween the fifth and sixth joints, being, however, almost exactly

equal to the length of the palp to the corresponding place.

Joint 1 short; joints 2 and 3 about equal in length, and longer

than joint 1; joints 4 and 5 each slightly more than twice as long

as joint 2 or 3; joint 6 bent backward upon joint 5, and only a

litle more than half as long; joints 7, 8, 9, and 10 grow succes-

sively smaller, both in length and in diameter; this part (the

“terminal part") of the oviger is usually somewhat flexed. The

terminal claw, which constitutes the eleventh joint of the append-

age, is small and curved. The first four joints are practically

free from hairs or spines; a few scattered short. spines occur on

joints 5 and 6; joints 7 to 10 are armed with three or four series

of denticulate spines with deeply incised margins. These spines

are longer on one side of the joint, and become smaller in each

of the longitudinal rows as one moves across to the other side

(Pl. 2, Figs. 9 and 10). Each of these joints has in addition

near its distal end a rather strong simple spine. At the middle

of the fourth joint is a prominent knob-like protuberance, which

probably carries the opening of what Dohrn (’81, p. 123) calls

the excretory organ.

Legs rather stout, somewhat less than twice as long as body

from anterior end of neck to tip of caudal segment. Coxal joints

(Pl. 2, Fig. 8) all short and broad, the second being a little longer

than the first and third, which are about equal. The femur and

first tibial joint are each a little shorter than the three coxal

joints together, while the second tibial joint is slightly longer than

the coxal region. Femur broadest, being about a third as long

as broad; tibial joints narrower. These joints are flattened from

side to side, so that the ventral margin forms rather a sharp edge.

‘I agree with Dohrn (’81, p. 123) that the terminal claw should be counted

as a joint.

No. 471] NEW BAHAMA PYCNOGONID 221

First tarsal joint short, squarish, bilobed distally; second tarsal

joint four to five times as long as broad, its inner (ventral) bor-

der only slightly curved, the outer (dorsal) somewhat more arched

(Pl. 1, Fig. 4). Claw short and rather stout, less than a third

the length of the second tarsal joint; somewhat curved towards

the tip; auxiliary claws wanting. The coxal and femoral joints

are only sparsely armed with short spines, which become longer

and more numerous on the tibial and tarsal joints, especially long

bristles (about as long as the breadth of the segments) occurring

along the dorsal margins of the second tibial and second tarsal

joints. On the ventral side of the second tibial joint near its dis-

tal end begin a number of thickly set short spines, which be-

come more numerous on the tarsal joints and give to them a

comb-like appearance. No "heel" is developed on the foot.

A few ova could be distinguished in the femoral joints, and the

openings of the oviducts could be seen in the usual position on

the ventral side of the second coxal joints of the second, third, and

fourth legs, and they were probably present also on the first pair

although they could not be made out.

Color in alcohol yellowish or light brown.

Measurements

Extent : 2 14 or 15 mm.

Length, anterior etd of tok to m ot oxudal segment 3.8 mm

Length of proboscis ; i 22 mm.

Length of caudal sedit" : ‘ : 1 : 1.0 mm.

Length of cheliforus : : : : ; 0.33 mm.

Length of palp Pe cl en ees 2.8 mm.

Length of oviger ie 35 mm.

222 THE AMERICAN NATURALIST [VoL. XL

LITERATURE

ALLEN, G. M., anp BARBOUR, T.

: 04. Narratisg of a Trip to the Bahamas. Printed privately, Cam-

bridge, 10 pp., 3 pls.

CanPENTER, G. H.

:05. The Marine Fauna of the Coast of Ireland, Part VI. Pyeno-

gonida. Fisheries, Ireland, Sci. Invest., 1904, vol. 4, pp. 1-8, pls.

1-3

Costa, O. G>

'61. Microdoride Mediterranea, o descrizione de’ poco ben conosciuti

od affatto ignoti viventi minuti e micoscropici del Mediterraneo.

Tomo primo, Naples, 8vo, xviii + 80 pp., 13 pls. (i, iA-xii).

DoHrn, A.

'81. Die Pantopoden des Golfes von Neapel und der angrenzenden

Meeres-Abschnitte. Fauna und Flora des Goljes von Neapel,

vol. 3, 252 pp., 18 pls. (i-x, xa, xi-xvii).

HaswELL, W. A.

'85. On the Pyenogonida of the Australian Coast, with Descriptions

of New Species. Proc. Linn. Soc. N. S. Wales, vol. 9, pp. 1021-

1034, pls. 54-57.

Sans, G. O.

'91. Pyenogonidea. The Norwegian North-Atlantic Expedition,

1876-1878, Zoólogy,vol. 6, pp. 1-163, pls. 1-15.

SCHIMKEWITSCH, W.

'87. Ueber eine von Dr. Korotnew auf den Sunda-Inseln gefundene

Pantopoden-Form. Zoól. Jahrb., Abth. j. Syst., vol. 3, pp. 127-

134, pl. 5

SLATER, H. H.

"I9. On a New Genus of Pyenogon and a Variety of Pycnogonum lit-

torale from Japan. Ann. Mag. Nat. Hist., ser. 5, vol. 3, pp. 281-

283.

PLATE 1 .

Barana latipes sp. nov., female

(All fig d with Abbé camera)

Fie. Dorsal

Fic. 2. — View from right side, ka legs of that side removed. X 12.

Fie. 3.— Left chelifo:

Fia. 4.— Foot of seule leg oy a side. x 50.

PLATE 2

Banara latipes sp. nov., female

(All figures except Fig. 6 drawn with Abbe camera)

fro Ae +h late ai

Fie. 6. up tee s viewed. direct] y from the

Fıc. 7.— Caudal vus from above (dria Vi at x 50.

Fic. 8 — Coxal joints of second right leg; o, Bose! i ot external genital opening.

Fic. a 2 and proboscis, with right cheliforus, palp, and oviger, as Us

Fia. ic — Oviger o f left side; v, row of spines shown enlarged in Fig.10. x 50.

Fig. — Row of denticulate spines marked zinFig.9. x 213.

Fra. Hd — Pap of left side. x 50.

ADDITIONAL NOTES ON BAHAMA SNAKES

THOMAS BARBOUR

THE specimens which form the basis of this paper are now all

the™ property of the Museum of Comparative Zoölogy at Cam-

bridge, Mass.

In December, 1904, a paper! was published in which a good

series of lizards but rather few snakes were reported on. Now

an opportunity is presented to offer notes on about forty speci-

mens of Ophidians, for last winter Mr. A. E. Wight collected a

number of fishes and reptiles during February and March; while

later Gustav Sabille returned to New York from Nassau with an

interesting lot of living snakes. These were also purchased and

advantage has been taken of this opportunity to study the species

while yet alive. Five examples of the New Providence Island

Boa from five to perhaps eight feet long have been presented to

the New York Zoölogical Society. They are still alive in the

Reptile House at Bronx Park, where shortly after their arrival

two specimens simultaneously gave birth to thirty-eight young.

I regret that I do not know the number in each litter. Mr. R.

L. Ditmars has also told me that several specimens of Alsophis

vudii ate a few Ungualiz which were in the same case and have

refused other food.

Since the afore-mentioned paper was published, Dr. Leonhard

Stejneger has published an excellent analysis of the herpetology

in a volume? on the Bahamas edited by Dr. Shattuck of Baltimore.

In general I agree very heartily with Dr. Stejneger’s conclusions,

but doubt whether Typhlops lumbricalis will ever be found on

New Providence. I, as well as others, have searched carefully

for it on this island and have never heard of its occurrence. With

‘Barbour, Thomas. “Batrachia and Reptilia from the Bahamas.” Bull.

Mus. Comp. Zoöl., vol. 46, no. 3, pp. 55-61.

*The Bahama Islands. Edited by George Burbank Shattuck. The Geo-

graphical Society of Baltimore; New York, The Macmillan Co., 1905, xxxii

+ 630 pp., plates and text figs.

229

230 THE AMERICAN NATURALIST [Vor. XL

far less opportunity to hunt for it carefully I obtained a specimen

near Marsh Harbor, Abaco, on July 6, 1904. I imagine that

for some unknown reason this species has skipped New Providence

in its northward progression, as Liocephalus carinatus appears

to have done, though, to be sure, the species has not yet been

taken on any island except on Great Abaco.

For the Northern Bahaman Boa Boulenger’s and Stejneger’s

application of Fischer’s name is undoubtedly correct.

Epicrates striatus Fischer.

E. strigilatus Cope. Barbour, Bull. Mus. Comp. Zoöl., vol. 46,

p- 59.

Six specimens just born, and one considerably older; all New

Providence Island stock. The very young ones are about 14}

inches long; the tail takes up 22 inches of this length. The

color of these young is considerably lighter than that of adults,

the opalescence is if anything more marked. One specimen is

diffusely blotched with white laterally.

An older specimen measures 28} inches in total length but part

of the tail is gone. This example is much darker in color than

the small ones. The pattern is the broken irregular one which

is characteristic of the adults of the species. In the very young

ones, on the other hand, there is a dorsal series of light blotches

separated by darker; below this laterally there is a light chestnut

stripe very iridescent; below this again are three darker stripes,

the uppermost lightest, the middle one darkest. Between these

are two light bands, the upper one buffish, the lower one almost

white. The bellies are ivory white.

The natives call this the “fowl snake." The squamation of

this species is typically so variable that the counts of these speci-

mens are of no especial interest.

Ungualia pardalis Gundlach.

Six specimens, all from New Providence Island. One of these

is younger than any examined heretofore.

No. 471] BAHAMA SNAKES 231

In my previous paper the dichromatism of this species was

mentioned. ‘This is also shown very well among these specimens.

One about 123 inches long is almost uniform buffish brown above

with a lateral row of small darker markings. A few dark mark-

ings are on the gastrosteges, which are yellow. The tail is blackish

above for one inch, below for less than 1 inch. Two other speci-

mens of about the same size are slaty blue with two dorsal rows

of squarish darker blotches. Between these pairs of markings

is a narrow very light band. Two others are brown with a double

row of dorsal markings. The sixth, and smallest, is 5} inches

long. It is slate-colored, the dorsal markings are fused. There

is a very distinct lateral row of squarish spots and on the gastro-

steges posteriorly there are two rows of dark spots generally in

pairs. The distal 4 inch of the tail is bright yellow with the ex-

treme tip black. Previously it has been noted that the amount

of black on the tail seemed correlated with age. ‘The scale counts

of these specimens are given in the same order as that in which

they have been mentioned :—

wa nn. 0, M ee

` 1524+ 31’ 149 -31' 1524-30' 157--33' 153+31’ 153-33

The natives call these “thunder snakes," because they say

that they frequently crawl about after severe rain storms.

This species is most frequently taken among the heaps of

broken rock which are piled about the trunks of orange trees;

or under stone walls. I have never seen one above ground.

Alsophis vudii Cope.

Twenty-four specimens, all from New Providence Island.

The largest specimen is 43 inches in total length with the tail

12 inches long. The smallest is about 21 inches long, with the

tail nearly one third of the total length.

The color of this species is vastly more variable than published

descriptions and material previously examined, had suggested.

One large one about 40 inches long, has the head and neck mottled

black and rich reddish brown. There is a black stripe on each

side of the neck. The color gradually changes until the posterior

232 THE AMERICAN NATURALIST [Vor. XL

half of the creature is- deep lustrous brown-black. Another

specimen is brick red above and almost salmon-color below.

Still another is uniform ashy gray above, marbled with darker

below. The top of the head is richly puncticulate with black

and red-brown. There is a dark stripe through the eye, also

several dark blotches on the neck region above. A number of

specimens are rich chocolate brown both above and below, often

with a light-edged dark stripe running through the eye. Several

examples are brown above and pinkish beneath. ‘The last speci-

men which I shall mention is dark iron-gray anteriorly, shading

posteriorly into olive-brown. This one also has a light-edged

dark stripe through the eye.

The Cuban specimens of A. angulifer do not show such varia-

tion. I can but think that the Bahaman examples are worthy of

specific distinctness.

The natives call this “chicken” or “whip snake." I have

added the scale counts of these individuals thinking that perhaps

they may be of use for comparison when someone procures a

large series of the Cuban form. It is remarkable how many of

the tails are imperfect.

New Providence Island specimens: —

ed, A Y RES

170+108’ 165+ ? ’ 109+ ? ' 165+104’167+105 ' 164+ ?

II mun a. et

169--?' 166--107' 159-112? 169-111! 162+ ? ^ 1714-19

u uM : LE MED

163--116' 163--101' 165+109’ 168+110’ 1702-107 165+117

17 17 17 17 17 17

ee ee ee ee PARU Ti nae SDN A

1654-106 166+ ?' 164--119' 170+111’ 169+113’ 162+119

Other specimens in the Museum collection show the following

scale counts :— 17 17 17 17

167+? ° 170-101? 1644118’ 161+ ?

The four following are from Andros. Island: —

COME ee

1714-121'166--? ’161+? " 164—118

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ALDER, J., AND Hancock, A. The British Tunicata, an Unfinished Mono-

graph. Vol. I. London, Ray Society, 1905, 8vo, xvi + 146 + 4 pp., 20 pls.

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234 THE AMERICAN NATURALIST [Vor. XL

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236 THE AMERICAN NATURALIST [Vor. XL

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Commercial Feeding-stuffs. R. I. Agric. Exp. Sta., bull. 106, pp. 95-107.—

WHEELER, H. J., HARTWELL, B. L., Wesseıs, P. H., AND Gray, J. P. Ana-

lyses of Commercial Fertilizers. R. I. Agric. Exp. Sta., bull. 108, 12 pp.—

Wirsow, C. B. North American Parasitic un belonging to the Family

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VOL. XL, NO. 472 APRIL, 1906

THE

AMERICAN

NATURALISI

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IN THEIR WIDEST SENSE

CONTENTS

Page

I. Fresh-water Copepoda of Massachusetts ge ara PEARSE MNE

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III. Anatomyjot.Cryptobranchus allegheniensis . PROFESSOR A. M. REESE 287

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AMERICAN NATURALIST

Vor. XL April, 1906 No. 472

FRESH-WATER COPEPODA OF MASSACHUSETTS

A. S. PEARSE

In her excellent review of the Crustacea of New England, Miss

Rathbun (:05) lists nine species of fresh-water copepods for

Massachusetts, as follows: —

?H eterocope sp. Diaptomus leptopus Forbes.

Cyclops vernalis Fischer. Cyclops viridis insectus Forbes.

Cyclops bicuspidatus Claus. .. Cyclops albidus (Jurine).

Cyclops serrulatus Fischer. Cyclops prasinus Fischer.

Cyclops phaleratus Koch.

As her paper cites the original description of each of these species

and the authority for its occurrence in Massachusetts, these points

need not be taken up here. The occurrence of Heterocope in

America is doubtful and it cannot properly be included on the

evidence that Cragin (83) offers.

To the above list I am now able to add the following: —

Eurytemora affinis Poppe. Epischura massachusettsensis n. sp.

? Diaptomus ashlandi Marsh. Diaptomus sanguineus Forbes.

Diaptomus pygmeus n. sp. Diaptomus spatulocrenatus n. sp.

Cyclops edax Forbes. Cyclops leuckarti Claus.

Cyclops viridis brevispi Herrick. Cyclops fuscus (Jurine).

Cyclops bicolor Sars. Cyclops varicans Sars.

Cyclops fimbriatus poppei Rehberg.

Canthocamptus illinoisensis Forbes. Canthocamptus staphylinoides Pearse.

Canthocamptus northumbricus ameri- Canthocamptus minutus Claus.

canus Herrick.

241

242 THE AMERICAN NATURALIST [Vor. XL

I have also observed all the species in Miss Rathbun’s list

except Heterocope and Cyclops prasinus. Eurytemora affinis has

never been observed before in America outside the Gulf of Mexico

(Foster, :04). The previous eastern range of Diaptomus ash-

landi is Indiana; Diaptomus massachusettsensis and Diaptomus

spatulocrenatus are apparently new to science. ‘The ranges of all

the species of Canthocamptus here listed, are considerably ex-

tended. The ranges of several species of Cyclops are widened

somewhat but this is of no very great significance as it is a cos-

mopolitan genus and all the species have been previously found

in the United States.

My thanks are rendered to J. A. Cushman for specimens from

various stations and for collections from Nantucket Island which

were made by Mariana Hussey, E. W. Morgan, and S. D. Rich-

mond. I am also indebted to I. L. Shaw for specimens from

Brookline, Wellesley, and Randolph.

The types of the new species here described have been pre-

sented to the Boston Society of Natural History.

Genus EunvrEMORA Giesbrecht

Eurytemora affinis Poppe.— This species occurred in a collec-

tion from Squam Pond, Nantucket Island, made by S. D. Rich-

mond, June 4, 1905.

Genus Episcuura Forbes

Epischura massachusettsensis n. sp.

This species is described from nine females collected by I. L.

Shaw at Wellesley, Mass., April 20, 1905. No males were taken

at that time nor in October when several dredgings were made.

ical NR 332.3 * 1

Description.— Of medium size, from above,

broadest about the middle, truncate at anterior end; six-segmented, first

segment almost half the cephalothorax and having a suture at its middle;

last segment distinct. Abdomen (Fig. 4) symmetrical, slender, five-

segmented (furca included). First segment very short, second segment

longest, third segment longer than first but shorter than fourth. Furca

twice as long as wide, hairy on inner margin, bearing three strong plumose

terminal setze and a smaller one at both the inner (not plumose) and outer

distal angles. Antennsm twenty-five-segmented and when reflexed, ex-

tending to middle of furca.

No. 472]

Fic.

Fig.

Fia.

Fic.

MASSACHUSETTS COPEPODA 243

GEN

ABIN

N N

p N

1.— Diaptomus pygmeus. Dorsal view of femal x 66.

2.— Diaptomus pygmaeus. Left fifth foot, usta x 343.

3.— Diaptomus pygmeus. Left fifth foot, male, x 290.

4.— Epischura massachusettsensis, Abdomen, female. x 65.

244 THE AMERICAN NATURALIST [Vor. XL

Fifth foot (Fig. 5) uniramose, three

segmented. First segment about as broad

as long, slightly tapering toward its free

end; armed at outer distal angle with a

slender spine. Second segment two thirds

as broad as long, slightly longer than pre-

ceding segment, armed on distal end with

a sharp spine at outer angle. Third seg-

ment half as broad as long and one third

longer than second segment, armed on

inner margin with three strong acute

spines which are denticulate on the outer

side; at the apex with three strong spines

(middle one denticulate) the innermost of

which is longest, being one third the

length of the segment; on the outer mar-

gin at the distal third armed with a small

1G. 5.— Epischura massachusett- strong spine.

TP E eoa Length of female 2.04-2.81 mm.

Genus Diaptromus Westwood

? Diaptomus ashlandi Marsh.— A single specimen, doubtfully

identified as belonging to this species, was taken at Cambridge,

May 5, 1905.

Diaptomus leptopus Forbes.—This species was common from

the middle of May to the middle of October. Localities: Cam-

bridge, Medford, Wellesley.

Diaptomus sanguineus Forbes.—Collected at Wellesley and

Medford in April and May.

Diaptomus pygmzus n. sp.

Figs. 1-3

Description.— A rather slender species of small size as the name indi-

cates. "The cephalothorax (Fig. 1) is widest at the middle; first segment

is thrice the length of the following ones, which are about equal; last two

segments are confluent above; last segment produced posteriorly and

armed on each side with a short acute spine. First abdominal segment

dilated laterally and armed on each side with a minute spine; second seg-

ment shorter than the third which equals the furca. The furca are two

thirds as wide as long and hairy on the inner margin.

No. 472] MASSACHUSETTS COPEPODA 245

Antenne twenty-five-segmented; in the female reaching beyond tips

of furcal setze and in the male to the ends of furcal rami. Male right

antenna not swollen anterior to geniculate joint; antepenultimate seg-

ment without special armature.

First basal segment of right fifth foot of male (Fig. 3) slightly longer

than broad and bearing a tubercle at its outer distal angle which is armed

with a sharp strong spine. Second basal segment three fourths as broad

as long; provided with a tubercle bearing three minute spines at the

inner distal angle, and the usual hair on the outer margin. First segment

of the outer ramus is as broad as long and has a ridge projecting on its

caudal surface near the distal end. Second segment of the outer ramus is

two and one half times as long as wide and bears a small spine on its

inner margin; outer margin has a long spine more than half as long as the

segment, which is placed slightly beyond the beginning of its proximal

third and is denticulate on its inner margin. Terminal hook about

twice as long as the preceding segment, not strongly tapering; curved

somewhat sharply near the center; inner margin denticulate throughout

its outer three fourths. Inner ramus of right fifth foot, one-segmented ;

extending well beyond the end of the first segment of the outer ramus;

hairy at the distal end on both margins

Basal segment of male left fifth foot broader than long; armed with a

spinous process at its outer distal angle. Second basal segment about as

broad as long; provided with the usual hair, and roughened at its inner

distal angle. First segment of the outer ramus longer than preceding

segment; twice as long as broad; inner surface hairy. Second segment

hairy on inner proximal surface; armed with a long finger-like terminal

process and also with a shorter conical process on the projecting inner

surface; the latter is separated from the rest of the segment by a suture.

Inner ramus one-segmented; broad at base and strongly tapering; hairy

on outer two thirds of inner peti and rough on basal third; about as

long as first segment of outer

First basal segment of che: rs foot (Fig. 2) produced at the outer

distal angle. Second basal segment triangular and bearing the usual

hair on theouter margin. First segment of outer ramus almost twice as

long as wide; slightly arcuate. Terminal segment about equal to the pre-

ceding in length; slightly curved; denticulate on the middle third of its

inner margin; armed on the outer side with two spines, the inner of which

is one third as long as the segment and the outer one somewhat less. The

inner ramus is longer than the first segment of the outer ramus; acutely

pointed; hairy on inner surface at the tip; armed with two spines slightly

more than one half as long as the segment.

Length: female, 1.0-1.09 mm.; male, 0.97-1.0 mm.

This species strongly resembles D. reighardi Marsh, but differs

from it in enough points to be easily distinguished. Specimens

246 THE AMERICAN NATURALIST [Vor. XL

have been examined from Arlington, Brighton, Cambridge, and

Wood’s Hole, which were taken in June, July, and August. It

therefore seems probable that this species is common in eastern

Massachusetts during the summer months.

Diaptomus spatulocrenatus n. sp.

Figs. 6-9

Description. — Cephalothorax robust and

six-segmented. The first segment is three

fourths the length of the cephalothorax, shows

` a dorsal transverse groove at about its middle.

Last two segments indistinct on the dorsal

surface. Last segment produced posteriorly

and armed with two sharp spines on each side

(Fig. 7). Abdomen stout, first segment long-

er than the remainder of the abdomen; sec-

ond segment one sixth as long as first and one

half as long as third. Furcal rami one fourth

longer than wide; hairy on inner margin.

Antenne twenty-five-segmented; those of

the female extending to the tips of the furca.

Right antenna of male (Fig. 6) geniculate;

swollen from the eleventh segment to the

geniculate joint; twelfth

segment armed with a

strong pointed process

the segment is wide;

ninth and tenth segments

armed with shorter proc-

esses; antepenultimate

segment armed with a

sharp curved process

which is a little over half

Fic. 6.— Diaptomus spatulo- as Der as the penulti-

crenatus, Right antenna, male, mate se

p Fifth rss of male (Fig.

8) dust First basal segment of left foot 00

reaching almost to end of first segment of outer side of female showing

ramus of right fifth foot; as wide as long; armed end of cephalothorax.

on the posterior surface with a long slender spine

at the outer distal angle. Second basal segment two thirds as wide

-T

No, 472] MASSACHUSETTS COPEPODA 247

as long, slightly tapering, the usual hair on the outer margin. First seg-

ment of outer ramus not quite half as wide as long, hairy at the inner distal

angle. Second segment hairy within, armed at the outer distal angle

with a strong blunt process which is minutely denticulate on its inner

margin, and at the inner distal angle with a slender hair which is as long

as the segment and hairy on the inner margin. Inner ramus two-seg-

mented, reaching almost to tip of outer ramus; first segment one fifth

Fic. 8.— Diaptomus spatulocrenatus. Fifth feet, male.

168.

Fig. 9.— Diaptomus spatulocrenatus. Right fifth foot, er x 247.

as 'wide as long; second segment spatulate, crenate on inner margin,

covered with minute hairs at tip and on inner and anterior surfaces.

Right fifth foot of male with first basal segment armed at the distal end

with a sharp spine; second basal segment armed with a large tubercle on

its inner margin at the distal third and the usual hair on the outer margin.

Inner ramus rudimentary being represented by a blunt curved process

which does not reach beyond the end of the second basal segment. First

248 THE AMERICAN NATURALIST [Vor. XL

segment of outer ramus about as long as second basal segment, over twice

as wide as long; second segment nearly twice as long as first, armed at

outer distal angle with a stout hook more than one half as long as the seg-

ment. Terminal hook stout, tapering, with a sharp curve at about the

middle, not quite as long as preceding segment, denticulate on inner mar-

gin beyond the sharp curve.

Fifth feet of female (Fig. 9) with the first basal segment bearing a very

large pointed process at the outer distal angle; second basal segment

armed with the usual marginal hair. Inner ramus one-segmented reach-

ing beyond the first segment of outer ramus, tips hairy and armed with

two plumose spines which are more than half as long as the ramus. Outer

ramus two-segmented; first segment about twice as long. as wide; second

segment one third longer than first, curved, bluntly pointed, denticulate

on outer two thirds of inner margin and armed with three spines on the

outer margin of which the inner one (plumose) is longest and the outer

one shortest.

Length: female, 1.47-1.58 mm.; male, 1.30-1.33 mm.

This species somewhat resembles Diaptomus lintoni Forbes.

The specimens upon which the above description is based, were

collected in Wigwam Pond, Nantucket Island, Mass., May 30,

1905, by G. D. Richmond. There were three males and two

females. One of the latter was carrying eggs and both bore

spermatophores.

Genus Cycrors O. F. Müller

Cyclops leuckarti Claus.— Localities: Cambridge, Middlesex

Fells.

Cyclops edax Forbes.— Localities: Cambridge, Lexington.

Cyclops viridis insectus Forbes.—'l'he most abundant member

of this genus in the collections examined. Localities: Arlington,

Cambridge, Brookline, Middlesex Fells, Nantucket, Waltham,

Wood's Hole.

Cyclops viridis brevispinosus Herrick.— Localities: Cambridge,

Watertown.

Cyclops vernalis Fischer.— Localities: Brookline, Arlington.

Cyclops bicuspidatus Claus.— This is a common species. Local-

ities: Arlington, Cambridge, Middlesex Fells, Nantucket, Wal-

tham.

Cyclops fuscus (Jurine).— Localities: Brookline, Middlesex

Fells, Wellesley.

No. 472] MASSACHUSETTS COPEPODA 249

Cyclops albidus (Jurine).— An abundant species. Localities:

Arlington, Brookline, Cambridge, Nantucket, Watertown, Welles-

ley.

Cyclops bicolor Sars.— This species was observed ony. once at

Cambridge, on August 6, 1905.

Cyclops varicans Sars.— Occurred once in a collection made on

Nantucket Island, May 30, 1905.

Cyclops serrulatus Fischer.— An abundant species. Localities:

Arlington, Brookline, Cambridge, Middlesex Fells, Nantucket,

Randolph, Watertown, Wellesley.

Cyclops phaleratus Koch.— Localities: Cambridge, Wellesley.

Cyclops fimbriatus poppei Rehberg.— Localities: Cambridge,

Middlesex Fells, Nantucket.

Genus CANTHOCAMPTUS Westwood

Canthocamptus staphylinoides Pearse.— This is an abundant

species. Localities: Cambridge, Middlesex Fells, Nantucket,

Reading, Wellesley.

Canthocamptus illinoisensis Forbes.—Common in a dredging

made October 9, 1905, at Wellesley.

Canthocamptus minutus Claus.— Localities: Middlesex Fells,

Stony Brook.

Canthocamptus northumbricus americanus Herrick.— This spe-

cies occurred in a collection made October 9, 1905, at Wellesley.

The length of the female was 1.16 mm. which is longer than Her-

rick ('95) gives. In other respects the female was similar to his

figures in Plate 29. No males were taken.

250 THE AMERICAN NATURALIST [Vor. XL

BIBLIOGRAPHY

CRAGIN, F. W.

’83. A Contribution to the History of the Fresh-water Copepoda.

Trans. Kansas Acad. Sci., vol. 8, pp. 66-80, pls. 1-4.

Fonnzs, E. B.

'97. A Contribution to a Knowledge of North American Fresh-water

Cyclopide. Bull. Ill. State Lab. Nat. Hist., vol. 5, pp. 27-82,

pls. 21-35

Forsss, S. A.

’76. List of Illinois Crustacea, with Descriptions of New Species. Bull.

Ill. State Lab. Nat. Hist., vol. 1, pp. 3-25

'82. On some Entomostraca of Lake Michigan and Adjacent Waters.

Amer. Nat., vol. 16, pp. 537-543, 640-650, pls. 8-9.

'90. On some Lake Superior Entomostraca. Ann. Rep. U. S. Comm.

Fish and Fisheries for 1887, pp. 701-717, pls. 1-4.

’93. A Preliminary Report on the Aquatic Invertebrate Fauna of the

Yellowstone National Park, Wyoming, and of the Flathead

Region of Montana. Bull. U. S. Fish Comm. for 1891, vol. 11,

pp- 207-258, pls. 37-42.

Foster, E.

:04. Notes on the Free-swimming Copepods of the Waters in the.

Vicinity of the Gulf ee Station, Louisiana. 2d Rep. Gulf

Biol. Stat., pp. 69-

GUERNE, J. DE, ET Riemann, f

'89. Revision des Calanides d'eau douce. Mém. Soc. Zool. France,

vol. 1, Q, pp. 53-181, pls. 1-4, 60 figs.

HERRICK, C. L.

’84. A Final Report on the Crustacea of Minnesota included i in the

Orders Cladocera and Copepoda. 12th Ann. Rep. Geol. and Nat.

Hist. Surv. of Minn., pp. 1-191, pls. A-V.

Herrick, C. L., AND Turner, C. H.

'95. Synopsis of the Entomostraca of Minnesota. Geol. and Nat.

Surv. of Minn., zoöl. ser., vol. 2, pp. 1-525, pls. 1-71.

LEHMANN, H.

:03. Variations in Form and Size of Cyclops brevispinosus Herrick

and Cyclops americanus Marsh. Trans. Wisc. Acad. Sci., vol.

14, pp. 279-298, pl. 23.

LILLJEBORG, W.

:01. Synopsis Specierum hucusque in Suecia observatarum Generis

Cyclopsis sive Bidrag til en Ofversigt af dei nom Sverige iaktagna

No. 472] MASSACHUSETTS COPEPODA 251

Arterna af on ET Svensk. Vet.-Akad. Handl., vol. 35,

. 1-118, pls.

:02. Synopsis een hucusque in Aguis Duleibus Suecie obser-

vatarum Familie Harpacticidarum sive Bidrag til en Ofversigt

af de uti Sveriges farska vatten hittills iaktagna Arterna af Fam-

ilien Harpacticidz. Svensk. Vet.-Akad. Handl., vol. 36, pp. 1-

75, pls. 1-4.

: 02a. Tres Species Nove Generis Canthocampti e Novaja Semlja et

Sibiria Boreali sive Trenne Nya Arter af Slaktet Canthocamptus

frau Novaja Semlia och Norra Sibirien. Bih. svensk. Vet.-Akad.

Handl., vol. 28, pp. 1-20, pls. 1-3.

MaRsH, C. D.

'93. On the Cyclopidz and Calanid: of Central Wisconsin. Trans.

Wisc. Acad. Sci., vol. 9, pp. 189-224, pls. 3-6.

'95. On the Cyclopid and Calanide of Lake St. Clair, Lake Michigan

and Central Inland Lakes of Michigan. Bull. Mich. Fish.

Comm., pp. 1-24, pls. 1-

:03. Ona N ew Species of Canthooamptus from Idaho. Trans. Wisc.

Acad. Sci., vol. 14, pp. 112-116, pl. 9.

PEARSE, A. S.

:05. Contributions to the Copepod Fauna of Nebraska and other

States. Proc. Amer. Micr. Soc., vol. 26, pp. 145-160, pls. 13-17.

:05. Fauna of New England. 5. List of Crustacea. Occasional

Papers Boston Soc. Nat. Hist., vol. 7, 117 pp.

SCHACHT, F.

'97. North tien Species of Diaptomus. Bull. Ill. State Lab. Nat.

Hist., vol. 5, pp. 97-208, pls. 21-35.

'98. North American Centropagid, belonging to the Genera Osphran-

ticum, Limnocalanus, and Epischura. Bull. Ill. State Lab. Nat.

Hist., vol. 5, pp. 225-270.

SCHMEIL, O.

92. Dostquad freilebende Susswasser-Copepoden. I. Teil, Cy-

clopide. 208 pp., 8

'93. Ibid. II. Teil, iopet. 120 pp., 8 pls.

'96. Ibid. III. Teil, Centropagidæ und Nachtrag. 192 pp., 14 pls.

Scorr, T.

:03. Some Observations on British Fresh-water Harpactids. Ann.

Mag. Nat. Hist., ser. 7., vol. 11, pp. 185-196.

VARIATIONS IN THE POLLEN GRAIN OF PICEA

EXCELSA'

JAMES B. POLLOCK

INTRODUCTION

WHILE teaching the reproduction of gymnosperms to a class in

the University of Michigan, the writer observed a very unusual

structure in a pollen grain of Picea excelsa L. (Pl. 1, Fig. 10). The

structure of this pollen grain was reported at the meeting of the

Botanists of the Central States, in December, 1901, and the sug-

gestion was made that possibly the extra cells found at the dorsal

side of the pollen grain should be interpreted as a prothallium,

much more highly developed than usual.

On using some of the same material for other classes it was

found that the structure in question occurred rather frequently,

along with other variations in the structure of the pollen grain of

Picea, so that it was considered of sufficient importance to report

in the present paper. As will appear later, a further examination

of numerous pollen grains has led to an interpretation of the obser-

vation different from the one suggested above.

The material was a part of the stock material of the botanical

laboratory at the University of Michigan, collected May 14, 1884,

but there was no indication on the label as to who was the collector,

where it was collected, or of the method of killing the material.

The condition of the material suggested that it was killed by putting

it directly into aleohol. In all the grains the protoplasm was con-

siderably contracted from the walls of the cells, but was otherwise

well preserved.

METHODS

In order to make the interior structure of the pollen grains as

plain as possible, the anthers, which were almost at the stage of

‘Contribution 88 from the Botanical Department of the University of

Michigan.

253

254 THE AMERICAN NATURALIST [Vor. XL

dehiscence, were allowed to stand in a solution of Kleinenberg’s

hematoxylin for twenty-four hours. They were then washed in

alcohol and changed very gradually from 96% alcohol to pure

clove oil. In the clove oil the pollen sacs were broken up and the

pollen grains set free in the oil. The pollen grains were studied

by mounting a drop of the oil containing them. It was found that

the pollen grains stained very unequally, some not having stained

at all, and others having stained so densely that the interior could

not be seen. Examination showed that the unstained ones were

often the most satisfactory objects for study, so no further efforts

at staining were made. This is the method used in demon-

strating the interior structure of the pollen grain to large classes,

and the author has no claim as the originator of the method.

When the grain is thoroughly permeated by the clove oil it becomes

so transparent that the interior can be seen very plainly.

The contracted condition of the protoplasm of the various cells

in the interior of the pollen grain made the outlines of these cells

very plain, and their number easy to determine with certainty in a

large series of the grains examined. Thus the crudeness of the

method of killing the material proved a decided advantage in the

study of it. Another advantage appeared in mounting the pollen

grains in clove oil, in that the same individual pollen grain could

be studied from different points of view on causing it to roll over

by means of pressure on the cover glass. Two views of the same

pollen grain are shown in Figs. 11 and 12, also in Figs. 13 and

14 PI I:

HISTORICAL

The older literature concerning the pollen grain has reference

to the external characters and structure, and for the internal struc-

ture there is no need to go farther back than 1834, when von Mohl

published his work, Ueber den Bau und die Formen der Pollen-

körner (34). In this article von Mohl cites the older literature

on the subject, and figures pollen grains of a few gymnosperms.

His figures, however, do not show internal structure, and only in

the work of Fritzsche (1836), do we first find figures which show

something of the internal structure of the pollen of gymnosperms

as we now know it.

No. 472] POLLEN GRAIN VARIATION 255

Among numerous species of angiosperms and a few gymno-

sperms Fritzsche (’36, p. 693) described and figured the pollen

grains of Pinus sylvestris and Pinus larix (Larix europea). The

terms he used for the different cells formed in the pollen grains

were totally different from those now in use. He did not regard

the bodies seen as cells, nor did he have any knowledge of their

function or homology. His figures show, however, a remarkable

accuracy of observation, if we take into consideration the state

of knowledge of his time, and the comparatively poor microscopes

and crude microscopical methods. He examined the pollen

grains in oil of lemon (Citronenél), and he undoubtedly saw one

of the disintegrating prothallial cells in both Pinus sylvestris and

Larix europea. His Plate 3, Figure 10, shows this for the former,

and Figure 14 for the latter. In Larix, besides the disintegrating

prothallial cell, he showed the cells which were later called the

“stalk” and “body” cells. The latter, Fritzsche called the cen-

tral vesicle, and the other two cells he called “ Zwischenkórper."

Later investigations have shown that in Larix, and sometimes

in Pinus also, there are two prothallial cells cut off which later

may disintegrate wholly or partly. It is not safe, however, to con-

clude that these genera vary in the number of prothallial cells

formed merely because Fritzsche did not see two of them while

other writers have done so. When we remember the difficulties

encountered by later observers equipped with much better micro-

scopes than Fritzsche could have had in 1836, the wonder is that

he saw so much.

Meyen (’39) pointed out that Fritzsche’s “Zwischenkérper’”’

were really cells, and that one of them served as stalk of attach-

ment to the larger cell. This was probably the first application

of the term “stalk” to this cell (’39, p. 189).

For about two decades after this time the literature concerning

the pollen grain is occupied mostly with evidence for and against

the view of Schleiden, advanced in 1837, that the embryo has its

origin in the pollen tube. Schacht (52, p. 407) went so far as to

say that the pollen is the egg of the plants, and that there is no real

analogy between animal and plant fertilization among phanero-

gams.

Hugo von Mohl (55), Hofmeister (55), and others opposed

256 THE AMERICAN NATURALIST [Vor. XL

these views, and it was only when Schacht himself discovered in

Gladiolus segetum (58a) a case in which the embryo undoubtedly

originated in a cell which was in the embryo-sac previous to the

advent of the pollen tube, that the controversy practically came to

an end in favor of the views of Hofmeister and von Mohl.

Schacht (’60) reported variations in the structure of the pollen

grains of several gymnosperms. On page 143 of the article desig-

nated he says that the pollen of Cupressus sempervirens has a

slightly elongated roundish form, which has divided into two un-

equal cells when the anther opens. Thuja orientalis shows the

same relation, only here oftener than in Cupressus (italics are mine)

further division takes place in the larger cell. Two of these extra

divisions are shown in his Figures 22 and 23, Plate 17. The text

cited above implies that similar divisions are formed in Cupressus,

but none are figured. Schacht also found variations in the num-

ber of cells in pollen grains of Larix europea, shown in his Figures

4 and 5. Since Schacht did not understand that one or more of

- the cells first cut off in these pollen grains may disintegrate, it is

possible that his observations do not really mean a variation in

the total number of cells formed in Larix, but his figures seem to

the writer to indicate that he actually observed such a variation

in Larix europea. He also states (760, p. 144) that Abies pectinata

(Tanne), Picea vulgaris (Fichte) [Picea excelsa L.], and Pinus

sylvestris (Kiefer) are like Larix in the interior of the pollen grain,

only in the first two there are almost always three cells, and in the

latter sometimes only two. No figures are given for these, but it

seems probable that Schacht really observed variations in the

number of cells in the pollen of the species named. Schacht was

probably the first to figure the sperm cells (58a) though he did not

understand their function.

Hofmeister (762, p. 406) described the structure in the pollen

of Juniperus, Taxus, and Thuja differently from what it is now

understood to be, but the apparent variation is probably due to a

wrong interpretation.

Juranyi in a preliminary notice in 1870 and in the fuller article

in 1872, reported a variation in the number of cells found in the

pollen of Ceratozamia longijolia Miq. He found that the one-

celled stage of the pollen grain divided into a large and a small

No. 472] POLLEN GRAIN VARIATION * 298

cell, the latter bulging into the former. The smaller cell divides

again into two unequal cells, the smaller lying against the pollen

grain wall, the larger one being hemispherical. Most pollen

grains are ripe at this stage of development, and undergo no further

changes till the time of fertilization. Often, however, one meets

a pollen grain which does not remain at this stage of development,

but goes a step farther in that the hemispherical cell divides once

more, so that a three-celled body is found in the interior of the

pollen grain. Juranyi's Figures 3 and 8 of Plate 33 (72) show

very well what he found. He, as well as Hofmeister, was mis-

taken as to the divisions of the smaller cells, since later investiga-

tions have shown that the small cells are cut off successively from

the larger one and that only the last of the smaller cells divides

when the “stalk” and “body or central” cells are formed. Jur-

anyi’s figure (’72, Pl. 33, Fig. 8), which shows three small cells,

may either be an actual variation in the number of cells, or it may

be a case of premature division into “stalk” and “central” cells.

No certain conclusion can be reached, but if the division into

“stalk” and “central” cells is the same in Ceratozamia as Webber

found in Zamia, then Juranyi’s figures of the former do indicate

a variation in the number of prothallial cells or else a two-celled

stalk. In 1882, Juranyi reported that he had seen a few cases

among the Cycadacee in which the small cells could divide parallel

to the long axis of the prothallium (Vorkeim), and that in Larix

europea he found some pollen grains in which the prothallium

ended with two cells lying beside each other, and separated by a

division wall. The upper cell had divided parallel to the long

axis of the prothallium. In the cases just mentioned in which

the small cells in some of the Cycadacee divide parallel to the

long axis of the prothallium, it cannot be questioned that we have

a case of variation from the normal, both as to the number of cells

formed, and as to the relation of those cells to each other in space.

In the cases of Larix europea in the upper cell there may have

been an earlier division than usual into the two sperm cells, though

at the time these observations were made the exact origin of the

sperm cells was not understood.

Strasburger, in Die Coniferen und Gnetaceen (72) added much

to our knowledge of these plants, though some of his observations

208. 4 THE AMERICAN NATURALIST [Vor. XL

were inaccurate and his earlier conclusions wrong. Strasburger.

wrongly interpreted the disintegrating cells at the base of the pollen

grain as mere slits in the wall having an origin similar to that of the

wings of the grain (’72, p. 127). Schacht (’60) had interpreted

these correctly as also had Meyen (’39). Following Hofmeister's.

suggestion Strasburger said that the cells formed in the interior

of the pollen grain could only be considered vegetative cells,

homologous to the prothallium of the fern. He supposed the large

cell of the pollen grain corresponded to an antheridium, believing

that it furnished the male gametes. He also thought that the cell

structure was the same in Pinus, Podocarpus, and Cupressus

(72, p. 130). Later investigations have shown that no two of

these are exactly alike. On page 131 Strasburger (72) remarks.

that the number of cells which are formed by division in the pollen

grain in Cycads and Coniferz remains constant. It never exceeds,

two, according to his observations. The report of a larger number

can only be founded on the view that the split in the wall is a disin-

tegrated cell.

In a paper published in 1875, Tschistiakoff wrote that where

there are several small cells, they arise by successive division of

the large pollen cell as in Larix, or the second cell can divide to

form two cells as in Ginkgo (75, p. 100). In Pinus according to

Tschistiakoff two, or at the most three small cells arise. The

one or two first cells arise by a real division of the large pollen

cell. The small cells may have their whole volume in the intine.

The third large cell, arching into the pollen grain, arises by divi-

sion of a small cell. In Abies the third cell forms by free cell

formation, this divides into two, each of these can divide again,

and these secondary cells can divide longitudinally or transversely.

The small cells (Suspensorzellen) can likewise divide.

Though some of the observations made by Tschistiakoff were

inaccurate, at least two new truths were presented, even if they

were not proved, namely, that several small cells were cut off

successively from the large pollen cell in such grains as those of

Larix and Pinus, and that the last one of the row of cells formed, .

became the progenitor of spermatozoid mother cells. His article

also mentions variations in the prothallium of Abies, and in the

number of cells formed in Thuja, where he says there may be two:

divisions instead of one, and these may be in different directions.

No. 472] POLLEN GRAIN VARIATION 259

Both of the two truths presented by T'schistiakoff were either

denied or ignored by later writers, (Strasburger, ’78; ’80). While

Juranyi (’82) admitted Tschistiakoff’s view of the origin of the

small cells, proving it in Cycads, and believing it true for Con-

iferee, both Juranyi and Strasburger believed the large tube cell

of the pollen grain furnished the male gametes and therefore

represented an antheridium, and it was not until Belajeff (’91-’93)

proved the contrary for Taxus baccata that the correct view was

finally established, and generally accepted. Both Belajeff (’91-

93) and Strasburger (92) showed that in the Abietinez also it

was not the tube cell, but the end cell of the row of interior cells

formed, from which the male gametes were derived. Strasburger

(84) had previously admitted that Tschistiakoff’s view of the

origin of the small cells in the pollen was correct, and he had also

shown that in Larix europea the third small cell cut off from the

large pollen cell divided into two cells which he named the “stalk”

(see Meyen, 739, p. 189) and “body” cells respectively. The

recognition of the "splits" in the wall of Larix pollen as disin-

tegrating cells (84, pp. 2-3) was a confirmation of the earlier

views of Schacht and Meyen.

Strasburger (’92) reported some interesting variations in the

number and arrangement of cells in the pollen of Ginkgo biloba.

Ordinarily there are three narrow cells and one large one found in

the ripe pollen grain. Usually the first two of the former are dis-

organized, but it often happens that two prothallium cells are

absorbed and yet two permanent ones are found. Also pollen

grains were repeatedly observed in which there were three perma-

nent inner cells preceded by one absorbed cell. Finally one grain

was seen in which all three prothallium cells were permanent, and

the first of these was divided longitudinally. Also (Strasburger,

'92, p. 18) the stalk cell of the antheridium appears to divide under

some circumstances.

Since 1893 the most important step in the progress of our knowl-

edge of the pollen of gymnosperms was the discovery of motile

spermatozoids in 1896 and 1897, by Ikeno ('98) in Cycas, by

Hirase ('97) in Ginkgo, and by Webber (797) in Zamia. Webber's

(:01) observations on Zamia and Ginkgo are interesting from the

point of view of variation in those genera. He did not work out

260 THE AMERICAN NATURALIST [Vor. XL

the details of the formation of prothallial cells, but in the species

of Zamia studied there were always at least two prothallial cells

cut off at one side and projecting into the grain as in Ceratozamia

and Macrozamia, and different from Cycas and Ginkgo, where

the walls are straight across the grain and not arching into it. It

seemed to Webber, however, that three prothallial cells were

occasionally formed, and in this case the first one was resorbed

as described by Strasburger and others in Pinus, Ginkgo, ete.,

remaining as a dark refractive layer in the wall of the pollen grain,

situated at the point of contact of the other cells. In many in-

stances in mature grains, and in later stages, during germination,

no indication of this resorbed prothallial cell can be observed,

but in some cases it is unmistakable. A careful investigation of

the development of the pollen in Zamia will have to be made before

it can be determined whether three prothallial cells are regularly

formed or whether the remnants of a third cell, occasionally ob-

served, are to be considered as cases of rare and somewhat abnor-

mal development.

Webber (:01, p. 24) clears up a point in the origin of the stalk

cell and the central cell (body cell of Strasburger) showing that

they originate by the division of the inner prothallial cell. Up to

the time of Webber’s full publication this point was quite obscure

and this brings it in agreement with the facts in other gymnosperms

investigated, except that the sterile cell bulges strongly into the

stalk cell and this had led to a wrong interpretation. Webber also

shows that Ginkgo is probably similar to Zamia on this point, and

Seward and Gowan (:00, p. 130) show that this is actually the

case. ‘They also state that in Ginkgo the pollen grain at maturity

contains a prothallium of from 3 to 5 cells.

Lang (’97) reports that Stangeria paradoxa has two prothallial

cells when pollen is shed, but his Figure 18, Plate 22, seems to

show three.

An interesting question is suggested by the different results

observed in two species of the genus Ephedra. Jaccard (’93)

reported that in E. helvetica at the time of anthesis there were in

the pollen grain three free nuclei, but not separate cells, and he

called these nuclei respectively the prothallium nucleus, the gener-

ative nucleus, and the tube nucleus. Land (:04) in Ephedra

No. 472] POLLEN GRAIN VARIATION 261

trifurca found two persistent prothallial cells, the first cut off by a

wall, the second not so cut off, while a third cell which he calls the

primary spermatogenous cell divides into the stalk and body cells,

which are not separated by a wall, but have a common membrane

(not cellulose but plasmic?). At time of anthesis therefore it has

two prothallial cells, a stalk cell, a body cell, and a tube nucleus.

Land (:04, p. 8) remarks that it is hardly to be expected that two

prothallial cells will be present in one species and wholly absent

in another of the same genus. The question, however, cannot be

settled in this summary manner. Jaccard’s observations can be

set aside only after further examination of the same species he

studied, and not by the examination of another species.

Miss Ferguson (:01, Pl. 12, Fig. 6) figures pollen grains of

' Pinus strobus with two prothallial cells, and also with one pro-

thallial cell (Pl. 12, Fig. 8), and in the latter case she labels the

one cell shown as the second prothallial cell. Of course this is on

the supposition that the same number of cells is always produced

in this species, and that in the pollen grain shown in her Figure 8

the first cell formed had disappeared. The question naturally

arises, however, whether this may not be a real variation, and the

prothallial cell shown, be the only one formed in this case. A

decisive answer of course must rest on further observations.

Coker (:02) has described some interesting variations in Podo-

carpus. The two prothallial cells do not promptly disintegrate,

but persist as cells, and the second, and sometimes the first also,

behaves in a manner hitherto unknown among the Conifers, and

only paralleled among the Cycads and in Ginkgo. The nuclei

enlarge and become as conspicuous as the generative nucleus. The

cytoplasm of the second prothallial cell loses its individuality and

its nucleus slips from its former position and lies free in the general

cytoplasm. This nucleus may divide amitotically before libera-

tion. In such cases the two nuclei generally slip out in different

directions and place themselves on opposite sides of the generative

cell (Coker, :02, Pl. 5, Figs. 8, 10). The number of cases in

which this division occurs is probably as great as the number in

which it does not occur. Hundreds of cases were found. In not

à few cases the first prothallial cell liberates its nucleus into the

general cytoplasm.

262 THE AMERICAN NATURALIST [Vor. XL

Arnoldi (:00) has reported a variation somewhat similar to this

in Cephalotaxus fortunei, where he found the tube nucleus dividing

amitotically, thus showing three free nuclei in the end of the pollen

tube besides the generative cells. Arnoldi actually observed one

case of division of the tube nucleus. He also reports that the non-

functional male nucleus may divide amitotically in the upper part

of the egg. Two tube nuclei were reported by Juranyi (’72, Pl. 34,

Figs. 11, 12) in Ceratozamia. Two or more tube nuclei have been

reported in the angiosperms, (Chamberlain, 97; Fullmer, '99;

Smith, '98). The last-named author found two tube nuclei in

half the pollen grains examined in Eichhornia crassipes.

Juel (:04) has found in Cupressus a variation which he seems

to have discovered for the first time among the gymnosperms. In

the pollen tube of this genus he found not merely two sperms, but -

from eight to ten, or even twenty in some cases. Chamberlain

(97) had found in angiosperms occasionally a pollen grain with

three sperm nuclei. In the same species, Lilium philadelphicum,

he also found a number of cases of a prothallial cell cut off at one

side of the pollen grain.

"Thompson (:05) has reported that in the pollen tube of Arau-

caria and Agathis there are supernumerary nuclei. His prelim-

inary note did not disclose their origin.

Lopriori (:05) shows that in Araucaria bidwellii these super-

numerary nuclei arise from cells formed in the pollen grain, pri-

marily by unequal division of the large cell of the pollen grain,

and the smaller cells thus cut off may themselves divide until there

are fifteen or more. These cells at first have walls but the walls

dissolve and the nuclei come to lie free in the pollen tube. Lopriori

believes these cells are spermatogenous cells and the nuclei derived

from them male nuclei. The writer does not accept this interpre-

tation of Lopriori and will give reasons for his opinion in con-

nection with a later discussion.

Miyake (:03) found in Abies balsamea that the second sperm

nucleus, the tube nucleus, and the stalk nucleus which are left in

the upper part of the egg after fertilization, may all divide, or at-

tempt to divide, before they disintegrate.. He says that the divi-

sion figures are more or less abortive or abnormal, hence the

divisions are apparently mitotic ones. This author saw one case

No. 472] POLLEN GRAIN VARIATION 263

of “double fertilization,” in which the second sperm nucleus

united with a secondary segmentation nucleus of the fertilized

egg.

If one could always rely on the observations reported in the

literature, the conclusion would have to be drawn that in other

gymnosperms than Cupressus and possibly the Araucarineæ there

were variations in the number of male cells. T'schistiakoff sup-

posed that there might be numerous spermatozoid mother cells

formed and Strasburger (’80, p. 49) writing of Juniperus virginiana

states that one of the two primordial cells found at the tip of the

pollen tube, divides into two, and often into two more, and these

are used for fertilization. At a later date, however, the same

author states (702, p..32) that in all the cases he has had oppor-

tunity to study exactly, the generative (primordial) cell of gymno-

sperms divides into two sister cells. Both are generative and even

in the Cupressinee both are called to perform a sexual function

(p. 33). In the Abietinez a difference in size between the cells

makes its appearance, and finally in Taxus a very unequal division

of the generative cell takes place, and only the larger sister cell

functions in fertilization. Since that statement was written by

Strasburger, numerous writers all report only two male cells from

each pollen grain, and we must conclude that the earlier observa-

tions were not correct as to the larger number; so that Cupressus

stands alone among the gymnosperms in forming numerous sperm

cells, unless the supernumerary nuclei reported in the pollen tube

of Araucarinee by Thompson (:05) and Lopriori should prove

to be sperm cells, as Lopriori believes or else this variation among

the gymnosperms has been generally overlooked. The variation

in the size of the male cells formed is common.

In a recent work on the gymnosperms, in fact the only one in

which an adequate discussion of the group is given from the modern

point of view (Coulter and Chamberlain, : 03) a variation is noted

in the Cycadacee and Ginkgo, as compared with other gymno-

sperms, in the relative position of the “stalk” and “body” cells.

They are said to stand side by side, instead of dorsiventrally as

they do in the other gymnosperms. ‘These descriptions (pp. 25,

42) are evidently based on the descriptions and figures of Hirase

for Ginkgo, and of Ikeno for Cycas. If Webber’s completed

264 THE AMERICAN NATURALIST [Vor. XL

work on Zamia (:01) had appeared somewhat sooner the descrip-

tions as to Ginkgo would necessarily have been different in the

above-mentioned work. Webber shows very conclusively that

in Zamia, and in all probability in Ginkgo also, the division into

stalk and central cell (body cell) does not leave those cells side by

side, but in the position found in the other groups of gymnosperms.

The bulging of the last vegetative prothallial cell into the stalk

cell probably led to a wrong interpretation of the earlier obser-

vations. Webber pointed out that the work of Ikeno and Hirase

was obscure on this point, and that before it can be certainly con-

cluded that any Cycad divides so as to bring the stalk and body

cell side by side, except as an unusual variation, the figures show-

ing the stages of development must be more convincing than those

now available.

Lawson (:04) found a variation in the behavior of the nuclei

and cells in the pollen grain of Cryptomeria japonica, as compared

with other gymnosperms which have the same number of nuclei.

The primary spermatogenous nucleus is free in the cytoplasm of

the pollen grain and not separated from the tube nucleus by any

membrane, except for a short time, and even then the membrane

is so difficult to distinguish that it almost escaped the observation

of the author. à

Variations in the pollen grain of several gymnosperms have been

reported in the Botanical Gazette by Coker (:04a) one of which is

much like some of those found in Picea excelsa by the present

writer. Coker’s Figure 7 of Larix europea is similar to my Fig-

ure 8. His Figure 6 is merely an earlier stage of the same thing.

His Figure 8 of Larix europea and Figure 4 of Cupressus semper-

virens show a condition that is like that found by Lawson in

Cryptomeria japonica., Coker’s Figure 9 of Larix europea shows

the last division wall in the pollen grain straight across, as is usual

in Cycas, instead of the strongly bulging wall that is usual in Larix.

Coker merely reports these as abnormal grains, apparently not

attaching any significance to them. It seems to the writer that

they are of some significance, at least as indicating the limits of

variation in the different genera and species of gymnosperms, an

when our knowledge of these variations is more complete they

may be of some assistance in determining whether or not the struc-

No. 472] POLLEN GRAIN VARIATION 265

ture of the pollen grain in gymnosperms is at the present time in a

state of stable equilibrium or in a process of retrogressive modifi-

cation. Coker’s Figures 6 and 7 will be further noticed in con-

nection with some of mine.

PICEA EXCELSA

In presenting my own observations I have considered it desir-

able to illustrate rather fully the different variations found in the

pollen grains of Picea excelsa L., and these illustrations show a

surprising range in the variation in internal structure of the pollen.

One fact that seemed especially significant was that so few pollen

grains could be found showing satisfactorily what has been called

the "normal" structure, that is showing two disintegrating pro-

thallial cells. For the larger number of pollen grains showed

only one such disintegrating cell without a trace of a second, even

as a split in the wall of the pollen grain. In order to get at the

proportion of those which showed only one disintegrating pro-

thallial cell, 466 pollen grains were counted. Only those were

counted which lay in the position most favorable to the necessary

observation, that is, the side view as shown in Figs. 1-6 (Pl. 1).

No pollen grain was counted unless its internal structure seemed

reasonably clear. Of the total of 466 grains counted, 310 or 66.5 95

showed only one disintegrating prothallial cell with no trace of

another even as a split in the wall; 73 or 15.7% showed more or

less plainly two disintegrating prothallial cells; 18 or 3.8% showed

no disintegrating cells; 65 or 13.995 were doubtful as to whether

they had one or two disintegrating cells. Even if all the doubtful

ones are counted as “normal” the percentage of those grains which

showed only one prothallial cell is still more than twice as great

as the "normal." Of course it may be said that in those grains

in which only one prothallial cell showed, the one first formed had

completely disappeared. But if it is not to be seen, what evidence

is there that it was ever formed? Two reasons may perhaps be

given for believing in its formation and disappearance. First,

in many cases in which two prothallial cells may be recognized

the one first formed is barely recognizable as a mere slit in the wall

of the pollen grain, and it is probable that in some cases the cell

266 THE AMERICAN NATURALIST [Vor. XL

disappears so completely as not to be recognizable at all. Second,

it is said that the pollen grain of Picea always forms “normally ”

two prothallial cells which disintegrate more or less, hence when

only one is found the other must have disappeared. Some va-

lidity must of course be granted to the first reason given. It is

probably true in some cases, but it is absolutely impossible to

prove its truth in a given case, hence the number of cases in which

it is true is purely a matter of conjecture. As to the second reason

given, it is a conclusion based on observation, and cannot be used

to prove the correctness of the observations upon which it rests.

Back of it lies the assumption that the “normal” is invariable,

an assumption which is far from the truth. Even if some pollen

grains of Picea have been shown to form two disintegrating pro-

thallial cells, it does not at all follow that they do so invariably.

Fig. 4 (Pl. 1) shows a pollen grain in which there were undoubt-

edly three disintegrating prothallial cells. All of them were per-

sistent, and separate from each other, and from the antheridium

part of the pollen grain, so that there was no difficulty in recog- -

nizing the number certainly. This grain was at the stage pre-

ceding the division which separates the stalk and the central cell.

The third disintegrating cell cannot be interpreted as a stalk cell,

first, because it so closely resembles the other disintegrating pro-

thallial cells in size and appearance, and second, because it is so

completely separated from the dome-shaped cell to which it would

be closely attached if it were a stalk cell.

Fig. 5 (Pl. 1) shows a variation in the position of the prothallial

cells, though their number is “normal,” that is, two. In Fig. 6

(Pl. 1) there is a variation in both the number and the position.

Three pollen grains were seen like Fig. 5, but only one like Fig. 6.

The latter shows without any doubt whatever a case of three

prothallial cells in addition to the stalk cell, central cell, and large

cell that forms the pollen tube. If Fig. 4 has been correctly inter-

preted, it and Fig. 6 furnish direct proof that the number of pro-

thallial cells in Picea may vary from what has been called the nor-

mal in the direction of a greater number and it seems much more

probable that they would also vary in the direction of a smaller :

number, since so many of the gymnosperms, as Thuja and Juni-

perus, have no vegetative prothallial cell.

El.

PLAT

ariation in the pollen grains,

Picea excelsa

268 THE AMERICAN NATURALIST [Vor. XL

Fig. 2 (Pl. 1) also seems to show three prothallial cells, one with

no protoplasm, and two with very little. In this case the walls of

the cells had persisted after the protoplasm had almost or entirely

disappeared, and so far as appearance was concerned seemed to be

like the inner layer of the pollen grain wall and continuous with it.

Usually, however, these cells do not show so persistent and evident

a membrane. Fig. 1 has the number regarded as the normal for

Picea. In this case also the membrane persisted after the proto-

plasm was entirely gone in the first one formed, showing that the

membranes were not plasmic, but in all probability of cellulose.

No mierochemical tests were made on them. Fig. 1 shows a

distinct separation of the protoplasm of the central cell from that

of the large tube cell. This separation was the result of plas-

molysis, probably due to the killing fluid. The boundary of this

cell, however, appeared to be only a plasmic membrane. At least

it was exceedingly thin and closely applied to the surface of the

protoplasm. |

Fig. 3 (Pl. 1) shows the typical arrangement of cells, with two

prothallial cells, but between the main part of the pollen grain

and the wings there are two spaces cut off by cellulose walls, con-

taining no trace of protoplasm. The writer was unable to decide

whether these should be considered as cells or not. ‘They seemed

to bear no definite relation to the main part of the pollen grain.

In this grain the membrane surrounding the central cell, and con-

tinued around the stalk cell, plainly projected beyond the limits

of the protoplasm where it had been pulled away from the wall of

the pollen grain by plasmolysis. This membrane was very much

thinner than the inner cellulose layer of the wall of the pollen grain,

but if it was only a plasmie membrane it was at least much firmer

than the protoplasm which it bounded, and from which it was

partly separated by plasmolysis.

There is shown in Fig. 7 (Pl. 1) a variation somewhat different

from those already discussed. Only one disintegrating pro-

thallial cell is apparent, but projecting into the tube cell of the

pollen grain is a row of three cells of approximately equal size

and structure except that the innermost one of the row is dome-

shaped while the others are flattened against the adjacent cells.

These three cells have equally large, prominent, and well preserved

No. 472] POLLEN GRAIN VARIATION 269

nuclei, and apparently either the stalk cell or the central cell of the

typical pollen grain has in this case divided again. ‘There was no

indication as to which of the two furnished the third cell found here.

Another interpretation of this pollen grain is possible. The outer-

most of the three almost equal cells might be regarded as the second

prothallial cell. The writer does not accept this interpretation of

that cell because of its large size, its prominent and well preserved

nucleus, and its close connection with and general resemblance to

the adjacent cell.

A very different type of variation is illustrated in Fig. 8 (Pl. 1).

Here the pollen grain, while having the typical form externally, is

divided into two equal portions by a wall perpendicular to the long

axis of the grain. This wall was very plain where it joined the

outer wall of the grain, but where the protoplasm lay against it

on both sides it could not be recognized certainly, and it was

represented in the drawing only where is was unmistakable. Its

position is probably indicated by the cleft in the protoplasm which

throws five cells on one side and three on the other. This gives

the typical form and arrangement of cells with two prothallial cells

on one side, while on the other side of the dividing wall no pro-

thallial cells are formed, and the three cells present apparently

represent a stalk cell, a central cell, and a tube cell. The writer

believes this difference in the two halves to be of some importance

in relation to the variation in number of prothallial cells. If the

number of those that disintegrate is invariably two for each pollen

grain, which ordinarily has one antheridium, in this double grain

where there are two antheridia, there ought to be two disintegrating

cells for each antheridium. If it be supposed that one set of two

prothallial cells serves as the basis of two antheridia, variation

from this arrangement and number of prothallial cells is found in

other grains of this same type, containing two antheridia. Fig. 9

shows a grain with the two antheridia in different positions in their

respective portions, and each has only one disintegrating pro-

thallial cell visible. Thirty-two grains of this double type were

studied in more or less detail. In most of them the two anther-

idia were placed as in Fig. 8. There was much variation in the

number of the prothallial cells connected (to the various anther-

idia. Put in the simplest form and using the single antheridium

270 THE AMERICAN NATURALIST [Vor. XL

instead of the double pollen grain as the basis of comparison

the following table shows the amount of variation.

Total No.

2 Pr KE No Fr. Cells Total Pollen

Cells Cells Cells Uncertain Antheridia Grains

No. of antheridia 4 24 18 18 64 32

In the group marked uncertain, the uncertainty was sometimes

due to inability to recognize clearly the total number of cells

present, and in other cases the position of the wall dividing the

pollen grain was uncertain where it ran between the disintegrating

prothallial cells. Only one sixteenth of this lot of antheridia shows

what has been called the normal number of prothallial cells. Of

even more importance than this fact is the further one that in no

case did both the antheridia in the same double grain have two

prothallial cells, as should have been the case if two is the normal

number. There were several cases in which the numbers for the

two antheridia were respectively 2 and 1, 2 and 0, 1 and 1, 1 and 0,

0 and 0. In those cases in which there were two prothallial cells

in one part, and one or none in the other part of the double grain,

it cannot be argued that some had disappeared by disintegration,

because the two parts of a double grain are usually at about the

same stage of development, and there is no reason to suppose that

two cells should so completely disappear in one part, and none in

the other. At least some cases should have been found in which

both parts of the double grain had two prothallial cells, and most

of the double grains should have shown the same number of pro-

thallial cells on the two sides of the dividing wall. Since neither

of these conditions was found to exist in the grains examined, and

in the light of other facts reported in earlier paragraphs of this

article, the writer feels justified in drawing the following con-

clusions: —

1. The number of disintegrating prothallial cells in the pollen

grain of Picea excelsa L. is not invariably two, and when a grain

is found which shows only one such cell it is not necessarily the

second prothallial cell and should not be so named. At the most

it can only be said that it is uncertain whether the case is one in

which a prothallial cell has completely disappeared, or whether

it is a case of normal variation.

No. 472] POLLEN GRAIN VARIATION 271

2. ‘The number of. vegetative prothallial cells certainly varies

from one to three, though the latter number is rare. It may also

happen that there are none at all. This condition is comparable

with that found in those gymnosperms which typically produce

no prothallial cell, as Juniperus, Taxus, and others. In Picea it

was found in 3.8 % of the pollen grains that contained only one

antheridium. :

3. The prothallial cells may vary in position as well as in num-

ber. 'lhe usual arrangement is dorsiventral, forming a single

continuous row with the stalk and central cells, but two prothallial

cells may be placed laterally in relation to each other instead of

dorsiventrally, and in case of three cells the arrangement may be

partly lateral and partly dorsiventral (Pl. 1, Figs. 5, 6).

4. In very rare cases the variation in number may extend to

that part of the row of cells which usually is composed of the stalk

cell and the central cell. An extra cell may be formed at this point

perhaps by division from the central cell. The stalk is then two

cells high.

5. The number of prothallial cells formed in the majority of

pollen grains would seem to be one, if the results obtained in count-

ing are to be fully relied upon, since 66.5 % of them showed but

one prothallial cell as against 15.7 % which showed two. This

difference is probably greater than it should be, since it cannot

be denied that one cell may have disappeared in some of those

grains which showed only one.

6. The membranes of the prothallial cells sometimes persist

after the complete disappearance of the protoplasm, hence they can-

not be plasmie, but are probably cellulose. In other cases there

is no trace of cellulose walls.

Coker (:04a) interpreted his double pollen grains of Larix shown

in his Figures 6 and 7, as having been formed by one instead of

two divisions of the pollen mother-cell, and the daughter cells

. having been retained within the mother-cell wall. In the pollen

grains of Picea studied by the writer this interpretation seems very

improbable, first, because no trace of the mother-cell wall was ob-

served around the pollen grain; second, because of the fact that

the “wings” of the pollen grain were always present, and always

typical in number and arrangement. , If these double grains were

272 THE AMERICAN NATURALIST [Vor. XL

contained in a pollen mother-cell, the pollen mother-cell wall was

euticularized and expanded into two wings. No indications of

this condition were observed.

A pollen grain with a very different appearance from that of any

yet described is represented in Fig. 10 (Pl. 1), which is a drawing

of the pollen grain whose discovery led to the observations recorded

in this article. In this grain we have the typical tube cell, central

cell, stalk cell, and what seem to be two disintegrating prothallial

cells, but in addition we find lying along the dorsal wall of the pol-

len grain a row of four rather prominent cells, each with a nucleus.

"These cells appear to be of unequal size and of somewhat different

shapes. They are separated from the rest of the pollen grain by

a wall which was continuous with the inner layer of the wall of the

grain, and which appeared just like it in structure. ‘The presence

of this wall was made evident by the contracted state of the proto-

plasm adjacent to it.

The structure of this grain was reported at the meeting of botan-

ists mentioned above, and it was suggested that possibly the four

cells represented a prothallium or gametophyte of a much larger

size than usual, and the pollen grain showed a reversion to an ear-

lier type of structure. At that time the writer saw no way of deter-

mining definitely whether that was the correct interpretation of

the structure discovered. In succeeding years, it was found that

the class material from which that pollen grain came also contained

numerous others similar to it as well as the variations of the differ-

ent kinds that are reported in this article.

After studying a number of grains of this same type the thought

occurred that perhaps a clue to the meaning of the unusual structure

might be obtained if the same grains could be studied from the dor-

sal as well as from the lateral view. Since the pollen grains were

mounted in clove oil, this could be done, by causing them to roll

over while observing them under the microscope. By repeated

trials it was found possible to study some of these abnormal grains

from all possible points of view, dorsal, ventral, lateral, and end

views. The dorsal and lateral views were the most important.

A total of 22 grains of this structure was studied, and many of

them were drawn in two or more views for purposes of compari-

son. Figs. 11 and 12 (Pl. 1) are respectively the lateral and dorsal

No. 472] POLLEN GRAIN VARIATION 273

views of the same pollen grain, and Figs. 13 and 14 (Pl. 1) are the

corresponding views of another grain. A study of the structure

shown in Figs. 12 and 14 as well as others more or less similar to

them finally suggested what the writer believes is the correct inter-

pretation of the extra cells along the dorsal wall of pollen grains

as shown in Figs. 10, 11, and 13. In Fig. 12 it will be noticed at

once that the cells labeled a and 6 are like the stalk and central

cell in a typical pollen grain, while cell c has the same relation to

the others as a tube cell, and cell d has no corresponding part in

the typical pollen grain. No cells appear to correspond to the

prothallial cells in the typical grain. In Fig. 14 the correspond-

ence to the typical pollen grain is less clear than in Fig. 12. Never-

theless there is a distinct suggestion of a similar structure. In

short, a study of the dorsal view of as many of these grains as possi-

ble led to the conclusion that grains of this type are not so very

different from the type shown in Fig. 8. They are double pollen

grains, but the division wall, instead of running from dorsal to

ventral side and dividing the grain into two equal parts, divides

it into two very unequal parts, and cuts off the smaller portion along

the dorsal wall. ‘This interpretation was made more certain on

looking over all the rough drawings made during the study, when

it was found that there was a very complete series of transitional

stages between the structure shown in Fig. 8 and that in Fig. 12.

In these transitional stages the division wall ran from some point

on the dorsal side obliquely toward one of the wings. Fig. 9 is an

example of one of these transitional stages, and Fig. 15 is a diagram

of what was seen in a dorsal view of a pollen grain with an oblique

division wall. "The dotted line zy is presumably the line of junction

of the oblique division wall with the dorsal wall of the grain. This

was of course not plain, owing to the oblique position of the reced-

ing wall. Cell a bulges into cells b and c like the cell which divides

to form the stalk and central cell. Cells b and c taken together

represent the tube cell. If, as is generally supposed, the tube cell

represents an antheridium wall, then we have here a case where

the antheridium wall is two-celled, a very unusual thing among

the gymnosperms. One other case was observed almost exactly

like this one, except for a slightly different position of the wall

separating cells b and c. It is just possible that the two tube

274 THE AMERICAN NATURALIST [Vor. XL.

nuclei found by Juranyi (’72) in the young pollen tube of Cerato-

zamia longifolia and by Arnoldi (:00) in Cephalotaxus fortunei

represent two cells in the antheridium wall or tube cell of the pollen

grain, but that interpretation can hardly be insisted upon very

strongly on the evidence now available.

In the case of the two or more tube nuclei in the pollen tube

of angiosperms, the above interpretation. ought to be considered,

but here there will be even more hesitation over its acceptance:

than in the gymnosperms.

As regards the large number of nuclei found in the pollen tube

of Agathis and Araucaria, Lopriori concludes that in Araucaria

bidwellii they are male nuclei, and that the cell-complex which is

formed in the pollen tube, and from which they are derived, is a

spermatogenous cell-complex. Lopriori’s conclusion is evidently

much influenced by Juel’s discovery of the numerous male cells.

in Cupressus. ‘The present writer cannot accept Lopriori’s con-

clusion until there is direct evidence that the nuclei in question

do actually function in fertilization. The reasons for rejecting

the conclusion at the present time are these: —

1. The cell-complex from which the nuclei are derived is formed

in the pollen grainfand not in the pollen tube as Juel found in

Cupressus goweniana.

2. It is formed, not from a single generative cell, but primarily

by the successive unequal divisions of the large cell of the pollen

grain, though secondarily the small cells.thus formed may them-

selves divide in different directions.

'These reasons seem sufficient to show that the cell-complex is

not spermatogenous in its nature, but that it is the vegetative part

of a male gametophyte, and as such is exactly the condition which

the present writer thought he had found when he first saw the

pollen grain of Picea represented in Fig. 10 (Pl. 1). Though this

interpretation proved to be wrong for Picea, Thompson and Lopri-

ori have probably discovered in the Araucarinev a group of gymno-

sperms which have the multicellular male gametophyte, and in

this particular at least they show the most primitive condition of

any of the gymnosperms.

It is to be hoped that these investigators will follow out the full

life history of all the cells and nuclei found in the pollen grain and

tube of the Araucarinez.

No. 472] POLLEN GRAIN VARIATION 275

In a recent short review of Lopriori’s paper, C. J. Chamberlain

also rejects that writer’s conclusion that the numerous nuclei are

male nuclei, but he gives no reasons therefor except “judging

by his figures.”

The structure in Fig. 16 (Pl. 1) requires little discussion. It

represents one of the somewhat irregular variations in a double

grain, but the portion marked a seems to consist of a mass of pro-

toplasm completely cut off from the rest, and contains no trace of

a nucleus. In order to determine the frequency with which the

variation of the double pollen grain occurred, a count was under-

taken. Fresh drops of clove oil containing the pollen grains were

mounted and all the grains on the slide were systematically counted.

A separate list was made of all the grains that were double, both

those like Fig. 10 and like Fig. 8 and also the ones intermediate

between these two. The total number counted was 1120. Of

these there were 27, or 2.4 % which showed the double character

more or less plainly. This was a much higher percentage than

was expected, but there is no reason to think a mistake was made

in the counting. Indeed it is more probable that some of the

double grains may have been overlooked. If any of them lay in

the position with the dorsal or ventral side toward the observer

they would almost certainly have been overlooked since in that

position their double nature is very difficult to recognize. ‘The

proportion among those that were counted did not impress the

observer as being any greater than the proportion among the

hundreds that were not counted but were looked over in making

the study of the variations found.

As a result of the study of the type of variation shown in Figs.

10-14, the following additional conclusions may be drawn: —

1. The three or four cells lying along the dorsal side of the pol-

len grain of this type do not constitute a prothallium or game-

tophyte of unusual size, an interpretation which the writer at one

time thought a possibility.

They constitute the smaller portion of a pollen grain sepa-

rated by a division wall into two very unequal portions, each of

which may form a more or less typical antheridium.

3. The cells of the larger part of such a pollen grain are similar

to the cells in a typical single pollen grain, and cases were observed

in which the number of prothallial cells visible was 2, 1, and 0.

276 THE AMERICAN NATURALIST [Vor. XL

4. In the smaller portion of such a double pollen grain there is

more variation in the size, number, and arrangement of cells, but

generally there is a distinct resemblance to the typical antheridium.

In several cases the similarity was striking and unmistakable.

5. In two cases where a cell which is like the one that divides

into the stalk and central cell, was plainly marked, the rest of that

portion of the pollen grain, which corresponds to the tube cell or

antheridium wall, was divided into two cells by an anticlinal wall,

that is, the antheridium wall was two celled (Pl. 1, Fig. 15).

6. In the material examined the proportion of double pollen

grains was found to be 2.4 % in a count of 1120.

Writers who feel justified in labeling a single prothallial cell as

the second one, may be inclined to reject some of the conclusions

reached in this article, especially the conclusion that a majority

of pollen grains in Picea excelsa form only one prothallial cell

(p. 271) on the ground that so much of the material studied was

abnormal. It has already been admitted that there is room for

argument as to the number of pollen grains in which only one

prothallial cell is formed, and the point at issue is really the deter-

mination of what is the normal number, or to state it more clearly

perhaps, the problem is to determine the limits of variation in the

number of cells in the pollen grains of Picea, and the relative

frequency of the different numbers. Stated in that form, it is

apparent that the abnormal, which is only the less frequent, is as

much a part of the problem as the normal. The abnormal is

only normal variation. Hence conclusions cannot be rejected

because based on observation of abnormal structures.

After consideration of both the historical and original parts of

this article it is obvious that variation in the number and arrange-

ment of the cells found in the pollen grain and pollen tube is

widespread among the families, genera, and species of gymno-

sperms. ‘They occur in those species which usually have no dis-

integrating prothallial cells, as well as in those which have one or

more such cells. ‘These variations cannot be dismissed with the

statement that they are abnormal, since the abnormal is only the

less frequent modification. It seems to the writer that they may

have a significance pera) the mere fact that the individual

species vary.

No. 472] POLLEN GRAIN VARIATION 217

A comparison between angiosperms and gymnosperms as re-

gards the structure of the pollen grain recalls the well known

difference. ‘The essential structure of the pollen is much more

uniform among the angiosperms, showing a spermatogenous cell

usually free within the larger tube-forming cell, the whole structure

to be regarded as probably a gametophyte reduced to an antheri-

dium, the tube cell forming the antheridium wall, and generally

there are no prothallial cells. Among the gymnosperms the struc-

ture of the pollen grain is not uniform in the different families and

genera, and it is not so much reduced as in the angiosperms. In

the more complex of the gymnosperms (Picea for example) there

is not only an antheridium represented, but there may be from

one to three disintegrating prothallial cells, and in addition the

antheridium has a cell, the so called stalk cell, which has nothing

to correspond to it in the angiosperms. This stalk cell is a sister

cell to the so called body cell or central cell, which divides to form

(usually) two sperm cells, and therefore corresponds to the sperm-

atogenous cell in the angiosperms. In those gymnosperms with

the simpler pollen grains no disintegrating prothallial cells are

formed, but the stalk and central cells are uniformly present, the

mother cell of these two being cut off at one side of the large tube-

forming cell. In the pollen of the simplest gymnosperms there-

fore there is one cell more than in that of the angiosperms, that is

the stalk cell. Cryptomeria seems nearer to the angiosperms in

this particular than any other gymnosperm, since Lawson (: 04)

has found that the cell cut off at the side of the pollen grain is

soon set free and lies within the cytoplasm of the large tube-forming

cell. Chamberlain (’97) has also found cases in pollen grains of

angiosperms which show one prothallial cell and more often it is

found in angiosperm pollen that the spermatogenous cell is cut

off at one side of the grain instead of lying free in the tube cell

(Coulter and Chamberlain, : 03, pp. 134-135).

The gymnosperms then, compose a group containing various

transitional stages, as regards the pollen grain structure, between

the very reduced condition characteristic of the angiosperms and

the condition found among the pteridophytes in which the male

gametophyte is more or less developed. Indeed some pterido-

phytes as Isoetes and Selaginella have more reduced male game-

tophytes than some gymnosperms, as Picea and Pinus.

278 THE AMERICAN NATURALIST [Vor. XL

The facts just presented suggest the question whether the gym-

nosperms at the present time are in a process of retrogressive modi-

fication in the direction of the condition found in the pollen of the

angiosperms, or have the gymnosperms reached a condition of

stable equilibrium, not so much reduced as that of the angio-

sperms and with different groups of genera stable at different

stages in the reduction process.

The mental attitude of those investigators who insist on labeling

a single prothallial cell as the second one implies a stable condi-

tion, with the number of cells formed invariable, and this mental

attitude seems to be the common one among the writers on the

subject. It seems to the present writer, however, that the number

and wide distribution of the variations found among the gymno-

sperms may indicate that the gymnosperms, or at least some of

them, are not in a state of stable equilibrium as regards the struc-

ture of the pollen grain, but that the process of reduction of the

male gametophyte is in progress. In Picea, for example, a very

few cases were found in which three vegetative prothallial cells

were seen, 15.7 % of the grains counted showed two, 66.5 %

showed one, and 3.8 % showed none. The number in others

was uncertain. In the case of the double pollen grains divided

into nearly equal parts, several showed no prothallial cell in one

part, and a few showed none in either part. ‘The extreme limits

of variation in the number of prothallial cells in the pollen grain

of Picea excelsa are therefore from 0 to 3, with 1 as the number of

greatest frequency.

These facts do not prove that Picea is in a condition of progres-

sive reduction of the male gametophyte, but at the very least they

allow that interpretation, and it is set forth merely tentatively.

Other investigations may either confirm or disprove it. Should

further investigations confirm this conclusion we should have a

case of a structure changed by gradual modification rather than

by mutation. The occasional variations found in angiosperms

in which the pollen grain shows a vegetative prothallial cell, or

several tube nuclei, or the spermatogenous cell cut off at one side

of the grain instead of lying free in the cytoplasm of the tube-cell

(Coulter and Chamberlain, :03, p. 134-135) may possibly have

a similar significance. If so, the condition now found in the pollen

No. 472] POLLEN GRAIN VARIATION 279

of angiosperms also has come about by gradual modification, and

the variations mentioned show that the “normal” structure is not

so firmly fixed but that a small proportion of the grains produced

reverts to a condition which was a stage in the gradual develop-

ment. If this interpretation of the variations is rejected, then they

must be looked upon as mutations, for whose cause we have noth-

ing at all to suggest.

It is worth noting that among the gymnosperms the reduction

of one structure in the pollen grain is not necessarily accompanied

by the reduction of other structures in the same pollen grains. For

example in Cupressus (Coker, : 04) no sterile prothallial cell is cut

off, and yet many sperm cells are formed instead of only two (Juel,

:04). On the other hand, Picea, which may have as many as

three sterile prothallial cells not only has the sperms reduced to

two nuclei in one cell but even one of those nuclei has undergone

a further reduction in size and only one, the larger, is functional

(Miyake, :03). In the reduction of the sperm cells therefore,

some of the gymnosperms have been modified to even a greater

extent than the angiosperms. The degree of reduction seems to

be closely associated with “use and disuse” of the parts concerned.

Reduction of one of the sperm cells takes place only in cases where

both could not function in fertilizing the egg. In the angiosperms

the second sperm cell functions by uniting with the polar nuclei

to form the endosperm, and this functioning whether a true fertil-

ization or not, has been sufficient to prevent the reduction and

possible suppression of one of the sperm cells.

The observations of Miyake (:03) that in Abies balsamea the

second sperm nucleus may divide, or attempt to divide before it

disintegrates in the upper part of the egg, and especially the obser-

vation that in one case this second sperm nucleus united with one

of the second segmentation nuclei of the fertilized egg, is sugges-

tive as to the possible way in which “double fertilization” may

have arisen. The sperm nucleus that is left over after the union

of the other one with the egg nucleus, has a tendency to unite with

any nucleus that may be available, and in the angiosperms the

polar nuclei offer the opportunity for such a union. It is not at

all necessary that either of the polar nuclei be the homologue of

an egg as Bonnier (:05) believes, in order to explain the union

280 THE AMERICAN NATURALIST [Vor. XL

with the male nucleus, since the latter has been shown to be able

to unite with a purely vegetative nucleus, even of the sporophytic

generation. This observation of Miyake's seems therefore to

strengthen the evidence that the endosperm of angiosperms was

vegetative phylogenetically (Coulter and Chamberlain, :03, p. 183),

and to weaken correspondingly the view that it was strictly sexual

in its origin (Bonnier, :05) and that the endosperm is to be re-

garded as a modified embryo.

If the introduction of the characters of the male parent into the

endosperm modified that endosperm so as to make it produce

food more suitable to the embryo with characters inherited from

the same male parent (Sargent, :00, p. 708) then the embryo

would be more vigorous, and more fit to survive in the struggle

for existence than the one not nourished by such an endosperm

Hence those individual plants in which “double fertilization

took place would finally become dominant in the competition

with others of the same species.

The reduction, disintegration, and final complete suppression

of the vegetative part of the male gametophyte may also depend

on the law of “use and disuse.” The vegetative cells of a well

developed male gametophyte function chiefly in the process of

photosynthesis. In most of the gymnosperms this function is

impossible since the pollen grain is soon enclosed in the micropyle

and light is excluded by the thick scales of the fertile cone. It is

then a waste of energy and food materials to form cells that do

not function, and this waste is only in part compensated for, if the

cells formed disintegrate later and thus become available as food

for the work necessary in forming sperms. Disuse leads to disin-

tegration of the useless cells, and their complete suppression is the

most advantageous condition of all.

It is interesting to note in this connection that in Araucaria

which probably has the well developed male gametophyte, the

pollen grain does not enter the micropyle (Thompson, :05), but

germinates at the distal end of the ligule, more or less entangled

on its serrated edge. From this point the pollen tubes pass in the

grooves on the surface of the ligule or scale, a distance of an inch

or more, to the micropyle. It would seem from this description

of Thompson’s that the pollen grains are exposed to the light dur-

ing the development of the tubes, hence the multicellular male

No. 472] POLLEN GRAIN VARIATION 281

gametophyte present may function in photosynthesis. Contin-

ued use has prevented in this case the reduction which took place

in those species in which the pollen grain enters the micropyle

directly.

In addition to the specific conclusions in regard to Picea (see

pp- 270 and 275) the following more general ones are drawn, some

of which are suggested rather than demonstrated :—

The variations in the male gametophyte and other structures

in the pollen of gymnosperms, indicate that in this group there are

examples of progressive reduction of some of those structures.

2. This reduction is by a gradual modification and not by

mutation, and is due to the disuse of the vanishing structures.

3. The different structures are not necessarily reduced to a

corresponding degree in the same species. ,

4. The suppression of the male gametophyte in gymnosperms

is a distinct advantage where the function of photosynthesis is

impossible to it.

5. The occasional prothallial cell in the pollen of angiosperms

indicates that in this group. also there was a reduction by gradual

modification.

The division of the non-functional male nucleus in the egg

of some of the gymnosperms and its fusion with a segmentation

nucleus of the fertilized egg in Abies balsamea, strengthens the evi-

dence for the view that the endosperm of angiosperms is phyloge-

netically a modified gametophyte and not a modified embryo.

7. The extremes in the variation of the male gametophyte

among the genera of gymnosperms are found in Araucaria with a

gametophyte of from 20 to 44 cells, (provided my interpretation

of Lopriori's observation is correct) and Cryptomeria japonica

(Lawson, :04), in which there is not only no vegetative male

prothallium, but in which even the division wall between the tube

nucleus and the primary spermatogenous nucleus is so fugitive

as almost to escape detection.

The writer has no intention of making any iiber investigations

along this line, as his special interests lie in another direction, but

he felt that the opportunity to make the observations here recorded,

though arising only incidentally, ought not to be neglected.

BOTANICAL DEPARTMENT OF THE

UNIVERSITY OF MICHIGAN

282 THE AMERICAN NATURALIST [Vor. XL

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ANATOMY OF CRYPTOBRANCHUS ALLE-

GHENIENSIS

ALBERT M. REESE

THE SKELETON

The Skull

SINCE the skull of Cryptobranchus allegheniensis is strong and

largely composed of bone, it is easy to prepare and to study. Figs.

1 and 2, A and B, are dorsal and ventral views of the skull proper

and of the lower jaw, taken from photographs.

The skull as a whole has essentially the same structure as that

of the Japanese giant salamander, described and figured by

Osawa (:02), but it differs from the latter somewhat in general

outline and in the shape of some of its constituent bones. Its.

length is greater in proportion to its width than is the case with

the Japanese species, and the anterior outline of the head, formed

by the maxillary and premaxillary bones, i is more rounded in the

American species, in which it forms an almost perfect arc of a.

circle. In the Japanese form the maxille and premaxille, as

figured by Osawa, are relatively heavier than in the American

species, and the posterior ends of the maxillary bones approach

more closely the anterior borders of the pterygoids. The shape

of the lower jaw is about the same in both species, but, if any-

thing, is narrower in the American salamander, so that it does.

not fit with very great precision against the upper jaw. The

anterior border of the skull is formed, as has been said, by the

maxillary and premaxillary bones (Figs. 1, 2, 3, Mx., P. Mz.), both

of which are armed with numerous small, conical teeth, there

being about 12 on each premaxilla, and 38 on each maxilla, making

100 teeth in the entire row.

The cartilaginous portions of the skull are not so extensive as.

in the Japanese salamander, and are superficially visible in the

region of the anterior nares only, the anterior part of the orbit,

the auditory region, and the articular surface of the quadrate.

287

AMERICAN NATURALIST [Vor. XL

288 THE

FıG. 1.—A. Ventral view of the mandible. B. Dorsal view of the ape from a

eee. Pr gular; Co., coronoid; Ct., ope nal (‘ alis

ipani”); T. dentary; E., NO, E. C., ethmoidal af

Mz., pe ister zu ei nares $.i O., ext

ME a ash al foramen; Or., P., parietal; Pl. t

g vetula pm quadrate; S., squamosal.

pre krontal; 2

premaxillary

entral view of skull ( igo a tesi

Fia. 2.—A. Dorsal view of mandible. B.

raph 1., angular; C., minute canals trough "aper geris ro-

tid canal; Co., coronoid; D., dentary; x., maxillary; O., exoccipi itai: eg

orbit; Pa., parasphenoid; P. Mz Tapes, Po. proótic; Pt., ptery-

, ve

goid; Q., quadrate; S., anorni: V.

No. 472] ANATOMY OF CRYPTOBRANCHUS 289

The bony cranium will first be described, and then a brief

description of the cartilaginous cranium will be given.

The premazille, forming the extreme anterior tip of the skull,

are firmly united with each other in the middle line, and articulate

less closely, on each side, with the adjacent maxilla. Their dorsal

surface is prolonged backward somewhat, to articulate with the

anterior borders of the nasals. Between them, in the mid-dorsal

line, is a small foramen, and each of them exhibits a small fora-

men on its anterior surface (Fig. 1, P. Mx.). Their antero-ventral

border is armed with the teeth above mentioned, while the postero-

ventral border articulates with the anterior border of the vomers

(Fig. 2, P. M«., V.). About half of the median border of the

nasal opening (V.) is formed by the premaxilla.

The two maxillary bones (Mz.) form the rest of the upper jaws,

and make up, in fact, about three fourths of their extent. Their

entire ventral border is armed, as has been described, with a single

row of teeth. The medial end of their are is in articulation with

the premaxillary, while the lateral end tapers somewhat and is

connected with the anterior angle of the pterygoid by a tough

band of connective tissue. On the dorsal aspect of the maxillary,

near the medial end, a triangular projection extends in a postero-

medial direction between the frontal and the prefrontal. On the

anterior border of each maxilla, at the base of the triangular pro-

jection just described, are two small openings, the infra-orbital

foramina.

The nasals (Figs. 1 and 3, Na.) lie just back of the premaxillze

and form the posterior half of the median border of the anterior

nares (N.). The two bones, when taken together, have somewhat

the shape of an arrowhead, the tip of the head pointing towards

the base of the skull. The base of the arrowhead articulates

anteriorly with the posterior projections of the premaxille that

have already been mentioned. In the mid-dorsal line the two

nasals articulate closely with each other, while their postero-

lateral borders articulate with the frontal bones. The anterior

half of each nasal is closely united, ventrally, with the dorsal side

of the corresponding vomer, and thus helps to form the septum

between the two nasal chambers.

The frontals (F.) are two large, much elongated bones that lie

290 THE AMERICAN NATURALIST [Vor. XL

just posterior to the nasals and form a considerable part of the

roof of the skull. Like the nasals, these two bones, when taken

together, have somewhat the shape of an arrowhead, the tip of

the head again being towards the posterior. Along the middle

line, where the bones articulate with each other, is sometimes:

seen a well marked ridge. Each frontal forms the posterior half

of the lateral border of the corresponding nasal opening, and

articulates laterally with the maxillary, prefrontal, and parietal;

anteriorly with the nasal, and medially with its fellow of the oppo-

site side. Ventrally the frontals are more or less closely united

with part of the cartilaginous cranium, to be described later.

The prefrontals (Pf.) are two elongated bones in the roof of

the skull, on the antero-medial border of the orbits. Each bone

articulates anteriorly with the corresponding maxilla, medially

with the frontal, and posteriorly with the extreme anterior end

of the parietal.

The parietals (P.) are two large bones that form the greater

part of the roof of the cranial cavity. The posterior half of each

bone is broad and angular, while the anterior half is long and nar-

row, and extends forward to articulate with the posterior end

of the prefrontal, as has already been stated. The posterior

halves of the two parietals articulate with each other, but the nar-

row anterior portions are separated from each other, and into

the space thus formed the posterior ends of the two frontals pro-

ject and articulate. The narrow, anterior part of the parietal

overlies and is more or less closely attached to the ethmoid, pres-

ently to be described. "The broad, posterior part of the parietal

articulates laterally with the squamosal, and posteriorly with the

lateral occipital. The sagittal suture, between the two parietal

bones, extends back to the antero-dorsal border of the foramen

magnum. A very small portion of this border is formed by the

medio-posterior extremities of the parietals.

The ethmoids (E.) will be described at this place, although they

are partially composed of cartilage even in the adult, and are

described by Osawa in connection with the cartilaginous crani-

um. ‘The ossified portion of the ethmoid is shown at E. in Figs.

land 3. It is an elongated rod of bone, attached dorsally to the

parietal, as has been mentioned, and ventrally to the parasphenoid

No. 472] ANATOMY OF CRYPTOBRANCHUS 291

ii!

a Rut

en,

Fic. 3.— The bones - the skull, disarticulated. jp ame a an suditoty

capsule; E., ethmoid (cartilaginous at each Meus z. on , maxillary

Na., n nasa al; O., exoccipital; P., parietal; Pa., paras ae Po prefrontal;

P. Mr., premax re Po., proótic; Pt., pterygoid; er ine S., squa-

mosal; vom

and, slightly, to the pterygoid. Extending laterally through the

midventral region of this osseous part of the ethmoid is a small

ethmoidal canal (E.C.). Anteriorly and posteriorly the osseous

ethmoid is continuous with the cartilaginous cranium of the nasal

and the occipital regions.

The pterygoid (Pt.) has, with the nr of the parasphenoid,

292 THE AMERICAN NATURALIST [Vor. XL

a greater surface than any bone in the skull. Seen from the dor-

sal aspect, it is nearly rectangular in outline, but seen from the

ventral side, it exhibits a long, postero-laterally projecting process

which underlies the squamosal and quadrate bones. Its anterior

and lateral borders are thin, and the former makes the irregular

outline of the posterior border of the orbit. ‘The antero-lateral

corner is connected with the maxillary by a band of connective

tissue, as has already been pointed out. The median border

underlies the ethmoid to a slight extent, and is attached ventrally

to the side of the parasphenoid. The posterior border is hid-

den, in a dorsal view, by the squamosal and quadrate, with which

it articulates. The above-mentioned postero-laterally projecting

process of the pterygoid is an elongation of the lateral and posterior

borders, and extends entirely across the squamosal until it shows

behind it, and forms a part of the articular surface for the lower

jaw. This projection of the pterygoid behind the squamosal

and quadrate is shown in Fig. 1. The pterygoid is somewhat

arched from side to side, with the convexity of the arch dorsad.

Above the postero-median corner of the pterygoid, in the angle

between the ethmoid, the parietal, and the squamous, is a marked

depression (see Fig. 1) covered in life by a membrane. In the

bottom of this depression several canals leading into the cranial

cavity may be seen. One of these canals is much larger than the

others, and is said by Osawa to be for the exit of the trigeminal

nerve. At the postero-lateral corner of the depression is a short

canal, formed by a narrow space left between the squamosal above

and the pterygoid below. ‘This canal does not lead into the cavity

of the skull, but extends backward to the outer side of the auditory

capsule, and seems to be an anterior continuation of the vertebral

canal; it is apparently the canal that Osawa calls the palatine.

The squamous bones (S.) are among the most important in

determining the shape of the skull. They are elongated, rod-

shaped bones that extend laterally, at right angles to the long

axis of the skull, and form the square outline of its base. Each

bone has the appearance of being slightly twisted, due to a well

marked dorsal ridge that extends nearly its entire length. The

medial end of the bone is somewhat flattened and enlarged, and

articulates with the side of the parietal near its posterior end.

No. 472] ANATOMY OF CRYPTOBRANCHUS 293

The distal end of the squamosal is firmly united with the enlarged

end of the quadrate, and partially overlies that bone. Ventrally

the squamous articulates with the posterior border of the ptery-

goid as has been described.

The quadrate bones (Q.) are two small bones that form almost

the entire articular surfaces for the lower jaw. A small portion

of these surfaces, however, is formed by the pterygoids. Each

quadrate is a small, triangular bone lying at the distal end of the

squamous above described, and largely covered by it. The heavy,

basal portion of the bone projects beyond the end of the squamous

and, together with the tip of the pterygoid, is covered with a thick

pad of cartilage for articulation with the lower jaw. ‘The slender,

medially projecting portion of the bone lies anterior and ventral

to the squamous, and dorsal to the pterygoid. It is more closely

attached to the former than to the latter bone. Osawa figures the

quadrate in the adult skull as entirely of cartilage, and describes

it with the cartilaginous cranium, but in the present form it is quite

fully ossified.

The tympanic bones, described by Osawa in the Japanese spe-

cies, could not be determined.

The exoccipitals (O.) form the greater part of the border of the

occipital foramen. Each bone presents a postero-laterally pro-

jecting condyle, for articulation with the first vertebra. ‘Through

the base of this condyle passes a horizontal canal of considerable

size into the posterior part of the cranial cavity. This canal is

probably for the exit of the vagus nerve. ‘The anterior part of the

exoccipital is much enlarged and is hollowed out to form the pos-

terior half of the auditory capsule. The dorso-anterior borders

of the exoccipital articulate with the posterior end of the parietal,

while the ventral border articulates with the posterior end of the

parasphenoid.

The occipital foramen or foramen magnum is markedly tri-

angular in outline, especially when seen from the dorsal aspect.

The apex of the triangle, which lies at the posterior end of the

sagittal suture, is some distance in front of the base, so that the

plane of the aperture, instead of being vertical, slants in a dorso-

anterior direction. Only a small portion of the base or ventral

border of the foramen is formed by the parasphenoid.

294 THE AMERICAN NATURALIST [Vor. XL

All of the bones described above are seen in a dorsal view of the

skull; those of the bony eranium that will now be described, are

best seen from the ventral aspect.

The parasphenoid (Pa.) is the only unpaired bone in the skull,

and is larger than any other single bone. It forms practically the

entire floor of the cranial cavity, as seen from the exterior. The

bone as a whole has somewhat the shape of a broad, blunt-pointed

dagger, with the point towards the anterior end of the skull, and

partially concealed, in a ventral view, by the posterior ends of the

vomers, with which it articulates (Pa. in Figs. 2 and 3). Later-

ally the parasphenoid articulates, for the anterior half of its length,

with the pterygoids. Just posterior to the pterygoids it articulates

dorsally with the small proótics, and posterior to the auditory fora-

men it articulates with the exoccipitals. Its extreme posterior

end forms the ventral border of the occipital foramen. A short

distance anterior to this point is seen, in some specimens, a well

defined, irregular transverse line (Fig. 2), which would seem to

indicate the presence of a basioccipital bone, but as no separation

of the bone along this line could be effected, the presence of a de-

finite basioccipital could not be determined. On each side of the

parasphenoid, close to its point of union with the proótic, is a canal

(C. C.), leading into the cranial cavity, called by Osawa the caro-

tid canal. Nearer the midventral line, somewhat anterior to the

preceding, are two very small openings (C.), probably for the en-

trance of minute blood vessels. ‘The ventral surface of the para-

sphenoid is smooth and nearly flat, except at the anterior end where

it is more or less convex, with a slight median ridge that fits in

between the posterior ends of the vomers.

The vomers (V.) are the large flat bones that form the base of

the anterior end of the skull and the floor of the nasal cavity.

‘They may, perhaps, be considered as formed of the fused vomers

and palatines. Each bone is roughly triangular in outline, one

side of the triangle being fused with the corresponding side of the

other bone in the midventral line. Another side, which is rather

deeply indented by a sort of bay, forms part of the inner border of

the orbital space; and the third side, which is in the form of an arc

and is armed with teeth, is attached to the maxilla and premaxilla.

'The row of teeth, lying on anterior borders of the two vomers,

No. 472] ANATOMY OF CRYPTOBRANCHUS 295

forms an arc that is almost exactly concentric with the arc of the

premaxille and maxille, except that there is a slight depression

in the middle where the two vomers meet. The anterior half of

the median edge of each vomer is elevated dorsally into a ridge,

and the median elevation formed by the union of these ridges sep-

arates the nasal chamber into its two parts, and unites the vomers

below with the nasals and the premaxille above. It forms, in

other words, the bony nasal septum.

The proöties (Po.) are two small bones of irregular shape that

form the antero-dorsal borders of the auditory capsules. Even

in the adult they are largely composed of cartilage, so that in the

dried skull they scarcely show from either the dorsal or the ventral

side. They are more closely united to the parasphenoid than to

any other bone, but they also articulate with the cartilaginous pos-

terior end of the ethmoid, with the parietals, with the squamous

bones, and, possibly to a slight extent with the pterygoids. There

are several canals that lead from the exterior to the cranial cavity,

in the neighborhood of the proötic. Of these the largest has

already been mentioned in connection with the pterygoid bone,

and is said by Osawa to be the trigeminal foramen. It is a break

in the median border of the proótie, rather than an actual canal

through the bone. The only other canal in this bone that can be

made out without difficulty is the facial, which lies in the edge of

the bony part of the proótie, just dorsal to the carotid canal, and

runs transversely through the bone to the cranial cavity.

Columella auris is the name given to two very small bones that

are found in connection with the auditory capsules. Each col-

umella is fan-shaped or palmate in outline, and, on account of its

minute size and loose attachment to the rest of the skull, is easily

lost in the preparation of the skull. The broad part of the bone

is connected by cartilage with the foramen ovale of the auditory

capsule, while the narrow end (the handle of the fan) projects lat-

erally and, according to Osawa, is connected by cartilage with the

quadrate, though this latter point could not be determined in the

present species. The columella does not show in either of the fig-

ures of the skull.

The cartilaginous cranium will now be described. It may be

divided, to use the terms adopted by Osawa, into two general

296 THE AMERICAN NATURALIST [Vor. XL

regions, an anterior naso-ethmoidal and a posterior petroso-

occipital, regions which are connected by two narrow longitudinal

bands in the position of the ethmoids. The space between these

bands is the pituitary space, and the bands themselves are ossi-

fied in their middle regions to form what we have already described

as the ethmoid bones, while their ends are cartilaginous to connect

anteriorly and posteriorly with the naso-ethmoid and petroso-

occipital regions respectively.

The naso-ethmoid cartilage serves chiefly as a lining to the nasal

chamber, and may be seen in a dorsal view of the skull, over a part

of the anterior nares and at the antero-lateral angle of the orbital

space.

The petroso-oceipital region is more extensive, and the cartilage

is there thicker than in the naso-ethmoidal region. It forms, as

the name would suggest, the cartilaginous basis of the occipital

region, and though in the adult it is largely ossified, there is a con-

siderable cartilage that persists even in the adult skull. The

thickest cartilage is found in the region of the ear, where it forms

a large part of the auditory capsule. Various parts of the petroso-

occipital region are more or less fully ossified to form the following

bones, whose form and position have already been described, and

which are described by Osawa in connection with the cartilaginous

cranium: the exoccipital (occipitale laterale), the proötic, the

quadrate, and the columella. The ethmoid, which forms the

middle of the longitudinal bands connecting the petroso-oceipital

and naso-ethmoidal regions, has also been described in connection

with the bony cranium.

It remains now to describe the bones and the cartilages of the

visceral skeleton.

The Visceral Skeleton

The visceral skeleton is made up of six arches: the mandibular

arch or lower jaw, the hyoid arch, and four visceral arches. It

differs, then, markedly from the Japanese species which, accord-

ing to Osawa, has only four arches, the last two visceral arches

being absent. ‘The visceral skeleton as a whole is large and strong

and, though consisting largely of cartilage, it persists throughout

No. 472] ANATOMY OF CRYPTOBRANCHUS 297

life. It forms the supporting framework to the floor of the capa-

cious mouth and throat so important in the process of inspiration.

The mandible or lower jaw (Figs. 1, 2, 4) is made up of two

distinet parts, joined together anteriorly, in the middle line, by

a short ligament of cartilage, the mandibular symphysis. As

may be seen from the figures, the curve of the anterior margin

of the mandible is not so wide as that of the upper jaw, so that

the two jaws do not fit together very closely. Each half of the

mandible is made up of three elements: the dentary, the coro-

noid, and the angular.

The dentary (D.) is the largest of these three bones, and extends.

from the symphysis almost to the posterior angle of the jaw. Its

anterior end is thick and rounded, while the posterior end is thin.

and pointed to fit against the outer e

surface of the angular. The ventro-

anterior surface of the dentary is

smooth, and is marked by a series

of about six small openings, mental

foramina, which do not show in

either a ventral or a dorsal view of

the mandible. The dorso-posterior,

or upper-and-inner, border of the

dentary is depressed to form a deep

alveolar surface, along the outer bor-

der of which are situated the small,

conical teeth in a single row. There

are about forty-five teeth in each

dentary. The alveolar surface ex-

tends for somewhat more than two

thirds of the entire length of the

bone, and ends posteriorly at the -

point where the dentary meets the Fre. 4.—The bones of the mandible,.

outer border of the coronoid. The a > patus:

teeth are all of nearly the same size,

except that those at the posterior end of the row are slightly

smaller than the rest. They are attached to the bottom and side

of the alveolar depression, so that their crowns sometimes project

but a short distance above the upper border of the dentary bone.

298 THE AMERICAN NATURALIST [Vor. XL

Individual teeth are frequently broken off, but whether they are

ever regenerated again the writer is not able to say.

The coronoid (Co.) is a spindle-shaped bone that lies on the

inner side of the mandible near its posterior end. Its inner or

medial surface is smooth and rounded except near the middle of

its length, where it is elevated and roughened to form the coronoid

process for the attachment of muscles. In the anterior corner of

the triangular depression between the dorsal borders of the dentary

and coronoid bones is a small canal leading towards the anterior

end of the jaw. It may be called the alveolar canal. A ventral

view of the jaw shows a more evident canal (Ct.) entering between

the dentary and coronoid bones, just at the anterior end of the

angular, as seen from the surface but really at some distance

behind this end as the anterior portion of the angular is hidden

between the two other bones. This canal corresponds, perhaps,

to the inferior dental foramen of higher forms. "The canal that

Osawa describes, in this region, passes directly through the coro-

noid bone; he calls it the “canalis chord: tympani.” The outer

surface of the coronoid (hidden, of course, by the other bones)

is deeply grooved longitudinally to receive a long, slender proc-

ess of the angular (Fig. 4).

The angular (A.) forms the posterior end of the mandible and

presents there an articular surface for attachment to the quadrate.

This articular surface is triangular in outline, with the apex of the

triangle towards the posterior. ‘The articular portion of the angu-

lar is a thick mass of cartilage, and extends forward to fill the

angular space between the dentary and coronoid bones that has

already been mentioned. Anterior to this angular space, this

cartilage is continued forward as a long, slender rod (Meckel's

cartilage) lying in a furrow between the dentary and the coronoid.

Meckel's cartilage extends for nearly three fourths of the length

of the jaw, or to about the middle of the row of teeth. The part

of the angular that is seen from the ventral aspect (Fig. 1, A) is

ossified, and extends, as may be seen from the figure, for some

distance, anteriorly, between the dentary and the coronoid. In

fact it extends farther in an anterior direction than is seen from

the surface, being covered for some distance by the coronoid.

The hyoid apparatus (Fig. 5), using that term to include both

No. 472] ANATOMY OF CRYPTOBRANCHUS 299

the hyoid and the visceral arches, has, as may be seen from the

figure, a very complicated structure. It differs from the same

apparatus in the Japanese salamander in having two more vis-

ceral arches, as has been said; also in the relative amounts of bone

and cartilage, and in the general form of the constituent parts.

The arches will now be described in order, from before backward.

The hyoid arch (H .,

H'., C.) is, as would

be expected, much the

largest of the arches,

andis composed of two

S-shaped bars united

medially by a small,

unpaired copula (C.).

Each bar is made up

of two closely united

segments (H., H’.), of

which the anterior one

(H'.) is nearly straight

and is united with the

copula, while the pos-

1 C., copula of hyoid

terior one (H.) 1S arch; C’., copula of first and second visceral arches;

strongly curved out- H., H’., elements of the hyoid arch; M., membrane

R between the first and second visceral arches; V'!-*.,

wards atits free or pos- first to fourth visceral arches.

terior end where it ends

in a cartilaginous surface for articulation with the skull. As may

be seen in the figure, nearly half of the posterior segment of the

- hyoid arch is bony (the cartilaginous portions being, in all cases,

dotted). In the Japanese form the entire hyoid arch is composed

of cartilage, and each bar is of a single piece, instead of being

of two pieces as in the present form. The copula or median con-

necting piece is of about the same shape in both species, and con-

sists of a short transverse portion with a pointed knob projecting in

a postero-dorsal direction. The elements of the hyoid arch are

flattened in a dorso-ventral direction, so that they are elliptical in

cross section. The whole hyoid arch has somewhat the shape of

a wide letter U, with the free ends of the letter bent widely apart.

Into the space between the two bars of the hyoid arch projects the

300 THE AMERICAN NATURALIST [Vor. XL

flat, cartilaginous copula (C’.) of the first and second visceral

arches. It is flat, broadly heart-shaped in outline, and is com-

posed of soft, fibro-cartilage. It is united around its periphery

with the inner border of the hyoid arch by a thin but tough con-

nective-tissue membrane. On the midventral line of this copula,

at its posterior edge, in a slight cartilaginous elevation to which

are attached the anterior ends of the first and second visceral

arches, the former to its lateral, the latter to its posterior border.

The first visceral arch (V !.) is composed of two slender, some-

what flattened, S-shaped bars united in the median line by the

copula that has already been described. Each bar of this arch

is composed of a single rod of firm, translucent cartilage. Along

its entire median border this arch is united, by a tough, fibrous

membrane, to the outer border of the second visceral arch (V?.)

which, in distinction to the preceding arches, is composed almost

entirely of bone. Its constituent bars, instead of being S-shaped,

are practically straight laterally though somewhat arched in a

dorso-ventral direction. Viewed from the ventral aspect, the two

bars of this arch form an almost perfect letter V. Each bar is

formed of two elongated bones, of which the anterior or dorsal

one is the longer. Both bones are nearly circular in cross section,

and are enlarged at each end, the two adjacent ends being the

larger, and somewhat flattened. The free end of the posterior

or ventral bone is tipped by a small piece of cartilage.

Between the two bones of the second visceral arch, on each side,

is a small pad of cartilage which extends medially and becomes

spread out for the attachment of the anterior ends of the third (V?.)

and fourth (V*.) visceral arches, of which the former is composed

almost entirely of bone, and the latter entirely of cartilage. The

third and fourth arches are formed of distinet bars; that is, they

are not united in the midventral line by a copula as are the pre-

ceding arches. The bars of the third and fourth arches on each

side are united with each other at both ends, and form a loop

which serves to stiffen the border of the permanent gill slit. The

third bar is of bone, and is tipped at the posterior end with a

small head of cartilage for attachment to the corresponding end

of the fourth bar. ‘This bar is cylindrical in cross section, and

is slightly curved, so that the loop is kept permanently open, while

No. 472] ANATOMY OF CRYPTOBRANCHUS 301

the elasticity of the cartilaginous fourth bar allows considerable

variation in the size of the loop and consequently in the size of the

gill slit. The anterior end of the third bar is united, for a short

distance, with the posterior bone of the second bar by the same

tough membrane that was noted in connection with the more an-

terior arches.

The Vertebral Column

The vertebral column of the American

salamander (Fig. 6) consists of from 39 to

42 bones or vertebrae. ‘The giant salaman-

der of Japan, according to Osawa, has in

its vertebral column forty-five vertebrae,

besides two cartilaginous rudiments at the

tip of the tail. The vertebrae may be divided

into three sets: those of the body, of which

there are 19; those of the tail, 19 to 22 in

number; and a single vertebra between these

‘two sets, the sacrum. The number of body

vertebrz, as might perhaps be expected,

seems to be more constant than the number

of caudals, though the variation in the latter

may be partly due to the great difficulty of

preserving the last few vertebra on account

of their small size and cartilaginous nature.

All of the vertebral centra, with the excep-

tion, of course, of the anterior surface of the

first, are deeply amphiccelous. The anterior

and posterior concavities are so deep that

they almost meet in the middle of the centra.

There is, however, no continuous passage

through the centra.

As a type of the body vertebra, or those

lying anterior to the sacrum, the tenth verte-

bra may be described (Figs. 6 and 7). As

is seen in Fig. 7, D, a lateral view, the cen-

trum is distinctly hourglass-shaped, and its

length is about twice its greatest diameter.

Fic. 6.— Dorsal view of

the entire vertebral col-

umn, with the ribs

attached (from a photo-

graph).

Like all of the other body vertebra, except the first, this vertebra

302 THE AMERICAN NATURALIST [Vor. XL

has strongly developed transverse processes (Figs. 6, 7, 8, T.),

to which are attached short, thick ribs (R.). These ribs, like the

processes to which they are attached, are flattened in an antero-

posterior direction, so that, at their points of attachment, they are

considerably thicker in a dorso-ventral direction than they are in

an antero-posterior direction. The ribs, with the exception of

those attached to the sacrum (to be presently described), stand

out at right angles from the vertebrz, and taper to a sharp, round

point. In the anterior part of the body the ribs are somewhat

longer than the processes to which they are attached, while in the

region near the sacrum they are shorter. ‘The transverse proc-

esses are of about the same length on all of the body vertebre,

and project rather strongly towards the posterior. The base of

nam 24 D

Fic. 7.—Four views of the tenth vertebra. A, Ventral. B,dorsal. C, posterior.

D, lateral. terior articular process; C., centrum; D., dorsal spine; P.

A., diego zi cmd process; R., rib; S. C., spinal canal; T., transverse

proce V. C., vertebral canal.

each transverse process is perforated by a small vertebral canal

(Fig. 7, V. C.). The dorsal or spinous process (Figs. 7 and 8,

D.) is small and inconspicuous in all of the body vertebree, and is

most prominent on the first.

No. 472] ANATOMY OF CRYPTOBRANCHUS 303

The posterior articular processes (Fig. 7, P. A.) have a rounded

outline, as seen from above, and are flattened ventrally where

they articulate with the underlying anterior processes of the suc-

ceeding vertebra. The anterior articular processes (Fig. 7, A.)

do not differ greatly from the posterior, except in having their

articular surfaces on the dorsal instead of the ventral side. ‘The

vertebrae of the body region resemble each other so strongly in

shape that it would be very difficult to say from just what part of

the body any given vertebra had been taken, but in an individual

skeleton the vertebrz in the middle region of the body are both

longer and heavier than those anterior and posterior to them.

The sacral vertebra differs from those immediately in front

and behind it only in the much greater development of the trans-

verse processes (Fig. 6, S.), and the ribs. The sacral ribs, since

they serve for the attachment of the pelvic girdle, are much heavier

and stronger than any of the other ribs. Instead of projecting

as sharp points straight out from the body, they curve downward

and end in articular surfaces for the attachment of the upper ends

of the two rods of the ilium.

The caudal vertebrze present more variations both in size and

form than do those of the body. The first caudal vertebra so

closely resembles the last body vertebra that it would be very

difficult, if not impossible, to tell them apart. The third caudal

vertebra may be described as a type of those of this region (Figs.

6 and 8). The chief differences between this vertebra and the

typical body vertebra are, besides the smaller size of the former,

the weaker transverse processes, the larger dorsal spine, and the

presence of a well developed hæmal arch. ‘Transverse processes

are found on the first eight of these vertebra, and are provided,

at least in the case of the first four or five, with minute ribs. These

processes diminish in size from before backward, so that those

of the eighth caudal vertebra are very small (Fig. 6). The dorsal

spines, on the other hand, become more prominent from before

backward, until they reach their greatest development in the mid-

caudal region, or, at any rate their greatest relative development.

As the caudal vertebra become more and more compressed later-

ally, the posterior articular processes approach each other until,

in the midcaudal region, they are not distinguishable from the

304 THE AMERICAN NATURALIST [Vor. XL

large dorsal process. Even in the third caudal, these processes

(Figs. 6 and 8, D., P. A.) have the appearance of being mere

articular surfaces on the sides of the spinous process. ‘The

anterior articular processes (Figs. 6 and 8, A.) also diminish in

size towards the posterior until, on the last few vertebree, they,

like the posterior articular processes, practically disappear, and

the vertebr in this region are united by their centra only.

Fig. 8. TER: views of the third caudal u > un B, posterior. C,

ventral. A., anterior articular process; C., ; D., dorsal spine; H.,

spine; H. A., hemal arch; P. A., DEL articular process; S. C.,

spinal canal; T., tranevered process,

The hemal arch, which is characteristic of the caudal vertebra,

is well developed on the third vertebra (Fig. 8, H. A.), in which

the two sides of the arch are prolonged ventrally into a long spine

(H.). As may be seen in Fig. 8 the canal formed by the hzemal

arch is larger than the spinal canal; this is true of all the caudals

except the first, which is without a hæmal arch.

The hinder caudal vertebrz, besides being laterally compressed,

show an actual concavity in each side of their centra.

'The two cartilaginous rudiments at the end of the tail, that

are described by Osawa, I have not been able to determine,

though I am not willing to say that they do not exist in the Amer-

ican as well as in the Japanese form. ‘There is, however, except

in the number of vertebrze, a strong resemblance between the

vertebral columns of the two animals.

No. 472] ANATOMY OF CRYPTOBRANCHUS 305

Skeleton of the Appendages

The Anterior Extremity.— Both pairs of appendages are small

and weak, and the two girdles are largely made of cartilage. ‘The

shoulder girdle is almost entirely composed of cartilage, and the

scapular, which is small, is the only part that is bony.

The sternum (Fig. 9) is so small and is composed of such thin

cartilage that it may easily be overlooked in a -— dissection.

It lies in the usual midventral position, and ER

is overlapped anteriorly for about half of

its length by the large coracoids, that is to

say, the coracoids overlap it on its ventral

side. In a medium-sized specimen it is

about 2.5 centimeters long and of nearly the

same width. It is somewhat shovel-shaped,

with the rounded edge towards the anterior

(Fig. 9). The ventral aspect is smooth and

slightly convex, while the dorsal side is correspondingly concave,

and is provided with a V-shaped thickening, which projects

slightly in an antero-dorsal direction. It is chiefly by this thick-

ening that the sternum is attached to the body wall. The edges

of the sternum thin out so gradually that it is difficult to deter-

mine where the cartilage ends and the fibrous tissue begins.

The coracoids, which are described by Osawa as being composed

of two parts, the procoracoids (Fig. 10, P. C.) and the coracoids

| (C.) proper, though there is nothing to distinguish the two regions,

are by far the most conspicuous elements of the shoulder girdle.

They are composed entirely of cartilage and, together with the

sternum, form a complete, though thin cartilaginous sheath for

the ventral side of the thoracic region of the body. "They overlap

each other almost completely, as each sheet extends almost to the

opposite side of the body. Like the sternum the coracoid is very

thin, especially at the edges, but, unlike the sternum, it has no

thickening on either side for muscular or connective tissue attach-

ments. At the outer edge the coracoid becomes considerably

thickened, where it articulates with the scapular and with the

humerus. With the scapula it is firmly united, but with the

humerus it forms a ball-and-socket joint, the glenoid cavity (Fig.

Fic. 9.—Dorsal view of the

sternum.

306 THE AMERICAN NATURALIST [Vor. XL

10, Gl.) being rather deep to receive the rounded head (H’.)

of the humerus (H.). The center of the coracoid is perforated

by an irregular aperture of varying size (F.), called by Osawa.

the “‘supracoracoid foramen."

The scapula and suprascapula (Fig. 10, Se., S. Sc.) form, to-

gether, a spatula-shaped structure whose area is small in com-

parison with that of the coracoid, with which it is firmly united.

The suprascapula forms the blade of the spatula, and is a broad,

thin sheet of cartilage, somewhat curved to conform to the curva-

ture of the side and back of the animal’s body. The scapula is

PU.

Fic. 10.—Anterior appendage. A, dag B, distal portion in -

ferent position. C., córacold: Cn centrale: F. foramen; a an cav-

ty; Hu humerus; H'., head of humerus; I., intermedium; diana med.

P., phalanges; P.C., procoracoid; X wu R'., radiale; re scapu S.

Sc., suprascapula; T., tuberosity of humerus; U., ulna; U’., ulnare; 3, 4,

5, distal row of carpals.

an elongated, somewhat flattened structure, slightly enlarged at

one end, where it is attached to the suprascapula, and considerably

enlarged at the other, where it is attached to the coracoid. It is

the only part of the shoulder girdle that is composed of bone.

The humerus (Fig. 10, H.) is rather thick in proportion to its

No. 472] ANATOMY OF CRYPTOBRANCHUS 307

length, and articulates with the glenoid cavity of the coracoid by

the round, cartilaginous head (H’.). Its more or less cylindrical

shaft is marked by a large tuberosity (T.) near its proximal end,

and is separated from the head by a well marked neck. At its

distal end it is broad, somewhat as in the human humerus, and

articulates with both the radius and the ulna.

The radius and the ulna are entirely distinct from each other,

and take nearly equal parts in the formation of both elbow and

wrist joints, though the ulna, as is usual, is the more closely as-

sociated with the humerus. The ulna (Fig. 10, U.) is slightly

longer than the radius (R.), and strongly resembles the corre-

sponding bone in the human arm, though it is, of course, not so

long in proportion to its diameter, and its shaft is not so nearly

cylindrical in section. Its proximal end is enlarged to form the

concave articular surface, the sigmoid cavity, and its distal end

is also slightly enlarged, and is provided with a disc of cartilage of

considerable thickness. ‘The radius presents no peculiarities in

structure. It enlarges rather rapidly from the center towards

each end, where well marked discs of cartilage are found.

The carpus, though composed entirely of cartilage, shows with

considerable distinctness the seven elements of which it is made

up. Two elements articulate with each of the forearm bones:

on the radial side are the radiale (R’.) and the centrale (Cn.), the

latter lying in about the center of the carpus; on the ulnar side are

the ulnare (U'.) and the intermedium (J.) Uniting the four

elements above described with the metacarpals are three distal

carpals (Fig. 10, 3, 4, 5), one of which is united with two of the

metacarpals. On the anterior appendage are four digits, each

of which is made up of an elongated metacarpal element (M.)

and two short phalangeal elements (P.), of which the more

distal tapers to an almost claw-like sharpness. The two middle

digits which are of about the same length, are somewhat longer

than the two outer ones. ‘There is no sign, on the fourth digit,

of the third phalangeal element described by Osawa in the Japanese

salamander. ‘The relative sizes of the metacarpal and phalangeal

elements are about the same in each of the four digits.

The Posterior Extremity.— The posterior extremity, consisting

of the pelvic girdle and the hind legs, is a rather curious mixture

308 THE AMERICAN NATURALIST [Vor. XL

of cartilage and bone. Its structure, in general, agrees closely

with the corresponding region in the Japanese species, as described

by Osawa, except in regard to the epipubis, which is markedly

different.

The pelvic girdle will first be described. ‘Taken as a whole,

it has a roughly triangular form. The apex is formed by the

anteriorly directed epipubis, while the basal angles are formed

by the dorso-posteriorly directed ilia. Its ventral surface is

somewhat convex, and, along its posterior half, is marked by a

slight, median, longitudinal ridge for the attachment of muscles.

Its dorsal surface is concave, with the most marked concavity

between the bases of the two ilia (Fig. 11). The greater part of

the pelvis is made up of the pubis, which is divided into two parts,

the pubis proper, and the epipubis.

The pubis proper is a shield-shaped plate of cartilage (Fig. 11,

P.), whose ventral convexity and dorsal concavity have been men-

tioned in speaking of the pelvis as a whole. It is almost com-

pletely divided into lateral halves by a median suture which is

especially evident at the posterior end of the pelvis, between

the two ischia (Fig. 11, S.). On each side of this suture, slightly

anterior to the middle region, there is a small opening (Fig. 11,

O. F.), the obturator foramen. ‘The posterior corners of the pubis

are elevated for the attachment of the ilia (J.), and under these

elevations the deep, well developed acetabula are situated.

Anteriorly, the pubis is prolonged into a long, cartilaginous

epipubis (Ep.), which, instead of being forked as in the Japanese

salamander and some other Amphibia, is a straight rod, slightly

broadened and flattened at its distal end and somewhat enlarged

both laterally and dorso-ventrally at its attached end. The union

of the pubis and epipubis is a close one, but allows considerable

freedom of motion.

Firmly united with the posterior end of the pubis, and continu-

ous with it, are two oblong plates of bone, the ischia (Is.). To-

gether, the ischia form a blunt, posteriorly projecting process to

the pelvis. ‘The ischia are separated along the middle line by the

median suture, but their adjacent edges are not quite parallel, so

that a slight cartilage-filled space is left between them at one place.

"There is also a small triangular piece of cartilage at their extreme

posterior end. |

No. 472] ANATOMY OF CRYPTOBRANCHUS 309

The ilia (I.), like the ischia, are of bony consistency, except at

their extremities, where there is a small amount of cartilage. They

are somewhat curved in a postero-dorsal direction, and are con-

siderably enlarged at their pelvic end, and less so at their sacral

end.

Fig. 11.—Posterior appendage, from the dorsal aspect. Cf., centrale fibulare;

Ct., centrale tibialis; Dt., distal row of tarsal elements; Ep., epipubis

femur; Fb., fibula: Fb., fibulare; I., ilium; Zn., intermedium; Zs., ischium;

` M., metatarsus; Of., obturator foramen; P., pubis; Pl., phalanges; S., su-

ture; T., tibia; T.’, tibiale.

The femur (Fig. 11, F.) is rather more slender in proportion

to its length than it is in the Japanese animal. Its proximal end

is enlarged to form a round, cartilaginous head, which articulates

with the deep acetabular cavity that has already been mentioned.

On the ventral side, near the proximal end, is a sort of trochanter,

or roughened projection for the attachment of muscles. The

shaft tapers rapidly from the enlarged proximal end to about the

middle length of the bone, where it is nearly cylindrical in cross

section, and is not more than half the diameter of the head. The

distal half of the femur is much broadened, in a dorso-ventral

direction, and flattened in an antero-posterior direction. This

marked flattening does not show in the figure because of the posi-

310 THE AMERICAN NATURALIST [Voi XL

tion in which the leg is drawn. This distal enlargement of the

femur is slightly convex on its anterior surface, and concave on

its posterior surface. On the convex anterior surface is a very

slight ridge, which is prolonged distally as an inconspicuous knob.

Almost the entire distal end of the femur articulates with the tibia,

but there is a small articular surface for the proximal end of the

fibula. Between the distal end of the femur and the proximal

ends of the tibia and fibula is a layer of cartilage of considerable

thickness.

The lower leg is made up of two entirely distinct bones, the

tibia and fibula. Of these bones, the tibia (Fig. 11, T.) is larger

and will be described first. It is considerably larger at its proximal

than at its distal end, and forms almost the entire articular surface

of the knee-joint. The proximal end is broadened and flattened

in the same planes as is the distal end of the femur, with which it

articulates. On the anterior surface of this end is a slight ridge,

corresponding to the ridge that has been noted on the distal end

of the femur. The shaft of the tibia tapers rapidly from the

proximal end to a point a little beyond the middle of the bone,

and then increases in size to form the somewhat flattened distal

enlargement, which articulates with the tibiale and centrale of

the foot. The flattening of the distal end is in the same plane as

that of the more enlarged proximal end. The distal, like the

proximal end, is provided with a well developed plate of cartilage.

The fibula (Fig. 11, Fb.) is not so long as the tibia, and, as is

shown slightly exaggerated in the figure, is strongly bowed on the

tibial side. 'l'he side away from the tibia is only slightly bent,

so that the bow is chiefly due to the shape of the surface next to

the tibia. The enlargement at the proximal end is rounded, and

articulates laterally with the side of the tibia and proximally with

the distal end of the femur. The shaft of the bone is somewhat

flattened, so that it is elliptical instead of circular in cross section.

` The distal end is more enlarged than the proximal, but is flattened

instead of being rounded. At the extreme end of each flattened

surface is an inconspicuous depression, not shown in the figure.

The fibula, like most of the other bones that have been described,

ends, both proximally and distally, in cartilage.

The tarsus, like that of the Japanese species, is composed of

No. 472] ANATOMY OF CRYPTOBRANCHUS 311

ten cartilaginous elements, which are arranged in two more or

less definite groups, the proximal and the distal, with two elements

in an intermediate position. Articulating with the tibia, or rather

with the cartilage that tips the distal end of the tibia, is the tibiale,

(T’.) an irregular, elongated mass of cartilage. Attached in the

same way to the fibula is the fibulare (Fb.’); and lying in an inter-

mediate position and articulating more or less with tibia, fibula,

tibiale, and fibulare is the angular intermedium (In.). The

distal row of tarsal elements (Dt.) is composed of five masses of

cartilage, all of about the same size, and each attached to the basal

end of one of the metatarsal bones. These distal cartilages are

smaller than the proximal. Between the proximal and the distal

rows, are two small elements (sometimes fused into one) called

by Osawa the “centrale tibiale” and “centrale fibulare” (Ct. and

Cj.). |

The metatarsus (M.) is composed of five elongated, cylindrical

bones, somewhat enlarged as usual at the ends. They are of

nearly the same length, though the first (on the tibial side) is

somewhat shorter than the rest, and the third and fourth are

somewhat longer.

The phalanges (Pl.) of the first, second, and fifth digits are

made up of two elements, while those of the third and fourth

digits contain three elements each. The terminal element of

each digit is a pointed, claw-like structure.

THE VASCULAR SYSTEM

For the purpose of working out the course of the blood vessels

the usual method of injecting the arterial and venous systems

with masses of different colors was used. ‘The injection of the

arterial system was accomplished with but little difficulty by

inserting the cannula into the well developed conus arteriosus,

and through it forcing the injection mass into all of the arteries.

But the injection of the veins was a more difficult matter, and

will be described in connection with the description of those

vessels.

312 THE AMERICAN NATURALIST [Vor. XL

The Arterial System

From the anterior edge of the ventricle leads forward the thick-

walled conus arteriosus (Fig. 12, T.). It is of considerable length,

and is more or less bent towards the right. It becomes consid-

erably enlarged anteriorly to form the conspicuous bulbus arte-

riosus (B.). The bulbus arteriosus gives off from its anterior

end, on each side, four branchial vessels (Fig. 12, 1, 2, 3, 4), which

diverge slightly as they pass towards the side. All four of these

arches are united with one another, just beyond the gill cleft (G. C.).

but it is from the second and third that the real systemic arch (S.),

is chiefly formed. This complicated arrangement of the branchial

blood vessels is, in the main, similar to that described in the Jap-

anese hellbender by Osawa, but differs considerably from the

description given by Chapman (’93), also of the Japanese sala-

mander.

The first arch, which may be called the carotid, extends for

some distance as a single vessel and then becomes slightly swol-

len to form a sort of carotid gland (C. G.), similar to that found

in the frog. From the median side of the carotid gland is given

off an artery which is distributed to the hyoid apparatus and the

floor of the mouth, and may hence be called the lingual (L.).

Just beyond the carotid gland the arch divides and reunites

again, giving off one or two small vessels to the neighboring parts.

Then, after continuing for some distance as a single vessel, it

divides into two vessels, the external and internal carotids (E. C.,

1.). Just before dividing into the external and internal carotids

the arch is connected with the main systemic arch by a vessel that

is called by Marshall the ductus Botalli, by Osawa the ramus com-

municans (Com.).

The second and third branchial arches (Fig. 12, 2, 3), after run-

ning more or less parallel to each other to a point back of the caro-

tid gland, unite to form the main systemic arch (S.). The third

arch runs along the anterior margin of the gill cleft (G. C.), and

gives off, just before uniting with the second arch, a branch to

the fourth branchial arch. This branch may be called the ductus

Botalli (D. B.).

Fic.

1sılilliitır

AERARII UE E m

fT y

bulbus arteriosus

12.—The arterial system, ventral aspect

nteric;

M., accessory mese 2 A. 86, anterior soap ar; B i

B tes hial; C. G., carotid glan , caeliaco-mesenteric on ramus

om ns; D., to dorsal region, near lungs; D. A., dorsal aorta; D.

ductus Botalli; E. C., external carotid Epi., epigastric; G nterior geni-

tal; Gas., gastric; G. C., gill cleft; H., hyoid; Hep., hepatic; Hy., hypogas-

€; I., internal carotid; Il., iliac; L., lingual; Lm., lumbar; O. V., occipito-

vertebral; ben creatic; P. A., onary; Pel., lvie; P. Epi., posterior

epigastric; P. M., posterior mesenteric; P. Sc., posterior scapular; = sys

temic arch; Sc., scapular; Sci nE, = sh tem bap Sp. , splen T

conus arteriosus; U. G., Preeti UY. caudal; J, 2, 3, 4, first to Nub

branchial arches,

314 THE AMERICAN NATURALIST [Vor. XL

A short distance beyond the point of union of the second and

third arches, the systemic arch gives off a well marked vessel (H.),

to the end of the hyoid apparatus, and some distance beyond this

it gives off an occipito-vertebral artery to the vertebral column

and occipital region (O. V.). After passing around to the dorsal

side of the digestive tract, the two systemic arches unite, just above

the heart, to form the dorsal aorta (D. A.).

The fourth branchial arch passes just posterior to the gill open-

ing, at the outer margin of which it is connected with the third

arch by the ductus Botalli. Beyond the ductus Botalli it gives

off an artery (Sc.) to the region of the scapula, and then two

small arteries (D.) to the muscles of the dorsal part of the body

in the region of the lungs. ‘The main branch of this arch con-

tinues posteriorly as the pulmonary artery (P. A.).

Some variation in the relative sizes of the vessels of the bran-

chial region occurs as well as some slight variation in their dis-

tribution, but the normal condition is about as described above.

The distribution of the blood vessels that arise as branches of

the dorsal aorta will now be described. The aorta and its branches

are so easily filled with the injection fluid that it is a comparatively

easy matter to work out their distribution, especially in the abdom-

inal region. In fact, the only part of the arterial system that offers

any difficulty is the outer part of the visceral arches, in the region

of the gill openings.

The branches of the aorta will be described in order from before

backward. The most anterior branches are given off in the

region of the heart, as a pair of rather small arteries (Fig. 12, G.

A.) which arise nearly opposite each other and extend in a pos-

terior direction to supply the anterior part of the reproductive

organs, especially the oviducts.

A short distance posterior to the last described arteries, are

given off the two subclavians (S. Cl.), the right vessel arising a

little anterior to the left. As might be expected from the slight

development of the anterior appendages, the subclavian arteries

are comparatively small vessels. On reaching the shoulder gir-

dle, each subclavian divides into four main branches. ‘The most

anterior of these (A. Sc.) supplies blood to the region in front of

the scapula. The next branch (Br.) is the brachial, and extends

No. 472] ANATOMY OF CRYPTOBRANCHUS 315

into the fore leg. The third branch (P. Sc.) extends to the region

posterior to the scapula, and also probably, to the posterior bor-

der of the fore leg. The most posterior branch of the subclavian

(Epi.) runs in a posterior direction, and carries blood to the lat-

eral part of the body back of the anterior leg; it is called by Osawa

the epigastric.

Some distance posterior to the subclavians is seen an unpaired

vessel (Gas.) which sends branches to the lesser curvature of the

stomach, and may be called the gastric. The next artery, which

may be called the coeliaco-mesenterie (C. M.), is a rather large one,

and branches almost immediately into three parts. ‘The most

anterior of these branches (Sp.) supplies the greater curvature of

the stomach, and also the spleen, and may be called the splenic.

The second branch of the cceliaco-mesenteric divides into three

smaller branches: a pancreatic (P.) supplying the pancreas; a

hepatic (Hep.) supplying the liver; and a third branch, the an-

terior mesenteric (A. M.), which carries blood to the anterior third

of the small intestine.

The most posterior of the three branches of the coeliaco-mesen-

teric artery is distributed to the small intestine posterior to the

region supplied by the anterior mesenteric; it is the first of several

vessels that supply blood to the posterior two thirds of the small

intestine, and that might be called accessory mesenterics (Ac. M.).

There are three unpaired accessory mesenterics posterior to the

one just described, and a fourth is formed as one of the two divi-

sions of another unpaired branch of the dorsal aorta (Ac. M.).

There are thus five of the so called accessory mesenteric arteries.

The artery (P. M.), with which the most posterior of the ac-

cessory mesenterics unites to form a single vessel is the posterior |

or inferior mesenteric and supplies blood to the anterior third of

the large intestine. Five or six rather large, unpaired arteries

(Lm.) are given off by the aorta, at more or less regular intervals,

between the origin of the cceliaco-mesenteric and the iliacs. These

lumbar arteries pass into the body wall along the mid-dorsal line.

Numerous pairs of urogenital arteries (U. G.) are given off by

the aorta in the abdominal region, and supply the kidneys and

reproductive organs. On account of the great elongation of the

kidneys in a posterior direction, the last of the urogenital arteries

316 THE AMERICAN NATURALIST [Vor. XL

lie as far back as the cloaca or even posterior to it. In the neigh-

borhood of the cloaca, the dorsal aorta gives off a pair of large

arteries, the iliacs (Il.) which are continued into the posterior

appendages as the sciatic arteries (Sei.). Each iliac artery gives

off, a short distance from its origin, a vessel, the posterior epigastric

(P. Epi.), which is chiefly distributed to the ventral body wall,

but which also sends blood to the pelvic region (Pel.). A short

distance distal to the posterior epigastric, each iliac gives off a

small artery to the pelvic region. From the right iliac an addi-

tional artery is given off, distal to those just described, to the

bladder and the posterior end of the rectum. ‘This is the hypo-

gastric (Hy.).

Posterior to the point of origin of the iliac arteries, the aorta

continues backward, with diminished caliber, as the caudal

artery (Y.) to supply blood to the tail. Besides several pairs

of renal arteries, there is given off from the aorta, just back of

the iliacs, a pair of arteries (Pel.), to supply blood to the dorsal

region of the pelvis. This completes the description of the more

important vessels of the arterial system. Without stopping to

describe the distribution of the more minute vessels, the venous

system will now be described.

The Venous System

The venous system is much more difficult to work out than the

arterial system, due chiefly to the difficulty of obtaining good

injections, especially in the region anterior to the heart.

The venous system, as described in this paper, will exhibit

more differences from that described by Dr. Osawa for the Jap-

anese giant salamander than were seen in connection with the

arterial system. The veins of the posterior region of the body

were injected, without especial difficulty, as follows: the abdom-

inal vein was injected both forwards and backwards; the portal

vein was injected forwards, beginning so far towards the tail that

practically the entire system was filled; and the posterior vena

cava was injected by cutting off the tail and inserting the cannula

into the caudal vein. The veins of the anterior parts of the body

were injected through the anterior vene cave, and it was here

No. 472] ANATOMY OF CRYPTOBRANCHUS 317

that the greatest difficulty was experienced in getting the injec-

tion fluid into the smaller vessels, in fact, it was only by repeated

injections at various points that even the more important veins

of this region could be filled. The posterior end of the posterior

cardinal veins could not be filled with the injection mass, even

after repeated attempts, so that the connections of these veins,

if any exist, with the other veins of the abdominal region could

not be made out. 5

The conspicuous, thin-walled sinus venosus (Figs. 13 and 14,

S. V.) into which the blood from the various parts of the body

is emptied, is formed mainly by the union of three large veins:

the two superior vene cave (S. C.), and the inferior vena cava

(I. C.). The pulmonary veins (L.), bringing blood back to the

heart from the lungs, as their name would indicate, unite with

each other dorsal to the sinus venosus, and empty into the latter

at a point whose exact location is difficult to determine on account

of the small size of these pulmonary vessels. The superior vena

cava of the right side seemed in most, if not all cases, to be attached

to the apex of the ventricle. What the object of this attachment

might be, was not determined. Each superior vena cava is formed

by the union of the following veins: the innominate (In.) which

is practically nothing more than the lateral continuation of the

superior cava itself, the external jugular (E. J.), and the posterior

cardinal (Car.).

The external jugular collects blood chiefly from the lower side

of the head, and is formed by the union of two veins which proba-

bly correspond to the mandibular and lingual or laryngeal, though

they could not be traced to their origin.

The posterior cardinal (Car.) empties into the superior cava

at a point nearly opposite the opening of the external jugular.

Throughout most of its course it lies deeply buried in the muscles

of the dorsal body wall, and, as has been said, its extreme poste-

rior termination could not be determined, owing to the impossi-

bility of obtaining a complete injection. It was traced back-

ward as far as the anterior end of the kidney, but whether beyond

that point it is simply lost in the body wall or is connected with

some of the veins of the abdominal region, could not be deter-

mined. Near its anterior termination the posterior cardinal is

318 THE AMERICAN NATURALIST [Vor. XL

joined by a vessel (S.) from the region of the shoulder, and a

short distance posterior to this point it is connected, by a sort.

PE CN

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Fig. 13.— The venous system, ventral aspect. A., "irre seek Br., brachial; C.,

caudal; Car., posterior cardinal; Cu., cutaneous; E. J., external jugular; G.,

genital; I. C., inferior cava; I. G., inferior gastric LE. re IL

iliac; In., innominate; J. V., vein of Jacobson; L., pulmonary; M., mesen-

eric; O., oviduct; P., portal; Pn., pancreatic; R., parietals; S. C., supe-

rior vena cava; S., from shoulder; Sp., posed S. V.,sinus venosus; V., ver-

tebral; Vs., from urinary bladder; X., plexu

of simple plexus of veins (X.), with the brachial vein (Br.) which

brings blood to the heart from the anterior appendage. To the

brachial and to the plexus of veins just mentioned, are added a

No. 472] ANATOMY OF CRYPTOBRANCHUS 319

number of small veins from the region of the shoulder. ‘The

innominate vein (In.) is formed by the union of the internal

jugular (I. J.) and the brachial (Br.). The main branch of the

former returns blood from the interior of the skull, and is joined

shortly before its union with the brachial, by two smaller vessels

(Cu.), leading from the side of the head. The brachial, as might

be expected from the small size of the fore leg, is a comparatively

small vein. This completes the description of the vessels con-

nected with the superior ven® cavee,as the vessels of the two sides

of the body in this region are alike.

The veins of the abdominal region will now be described.

Since these vessels are usually injected without difficulty, their

distribution may be made out with comparative ease. One of

the largest and most noticeable veins in the body is the abdominal

(A.). It adheres closely to ventral body wall, slightly to the

right of the median line, and, unless care be taken, may easily

be cut in opening the abdominal cavity. In the diagram it, like

the veins from the stomach and intestines, is for the sake of clear-

ness drawn towards the side. Posteriorly it is formed chiefly

by the union of the two iliac veins (Il.),a union which takes place

just anterior to the cloaca (clo.). The iliac veins return the blood

from the posterior appendages, and, like the brachial veins, are

of comparatively small size. A short distance anterior to the

point of union of the iliac veins the abdominal vein receives a.

very small vein (Vs.) from the urinary bladder. Into the most

anterior quarter of the abdominal vein, near to its junction with

the liver, empty several (eight or nine) veins, the parietals (R.),

which return blood from the ventral body wall. Anteriorly, the

abdominal vein enters the liver, a little in front of the apex, and

becomes broken up into capillaries, though it may be traced along

the ventral surface of the liver for a considerable distance in an

anterior direction.

The arrangement of the veins from the stomach and intestines,

the hepatic-portal system, is rather peculiar, and will now be

described. The blood from practically the entire length of the

intestines, both small and large, is collected by a single vein (M.)

which may be called the mesenteric. A short distance posterior

to the liver, this vein unites with the splenic vein (Sp.) to form the

320 THE AMERICAN NATURALIST [Vor. XL

main branch of the portal vein (P.) through which the blood finds

its way into the liver. The splenic vein, as its name would indi-

cate, collects blood from the spleen, but it brings blood also from

the middle region of the stomach. The greater part of the blood

from the stomach is collected into two well marked veins, the

superior and inferior gastries (S. G., I. G.) which empty into

that part of the abdominal vein which has already been described

as extending for some distance along the ventral side of the liver.

Of these two gastric veins, the inferior is the larger, and empties

into the abdominal vein at some distance behind the superior

gastric. Emptying into the abdominal at almost the same place

with the inferior gastric, is a vein of considerable size, the pan-

creatic (Pn.). The portal vein proper, then, brings blood to the

liver from the intestines and the spleen; but most of the blood

from the stomach and apparently all that from the pancreas is

carried into the liver through the abdominal vein.

It now remains only to describe the system of the inferior vena

cava, and especially that part of the system that lies posterior to

the liver. The blood from the tail is collected into a caudal vein

(C.) that, after entering the abdominal cavity, becomes the in-

ferior or posterior vena cava (J. C.). This posterior part of the

inferior cava lies between and slightly ventral to the kidneys, and

is so closely associated with these organs, from which it receives

, numerous veins, that its individuality as a distinct vessel seems

almost lost. Extending along the distal sides of the kidneys, and

connected at frequent intervals by small vessels with the inferior

cava, are the more or less distinct veins of Jacobson (J. V.). Each

vein of Jacobson receives about six vertebral veins (V.) from the

corresponding side of the vertebral column. On account of the

great number of the renal veins and the close attachment to the

kidneys of the veins of Jacobson, the details of these veins are dif-

ficult to determine.

'The blood from the reproductive organs is emptied into the

inferior cava through several pairs of genital veins (G.), some of

which lie anterior to the kidneys while some cross the anterior

ends of these organs to reach the inferior cava. In the female,

a comparatively large vein leads from the anterior end of each ovi-

duct to empty into the inferior cava just behind the liver (O.).

No. 472] ANATOMY OF CRYPTOBRANCHUS 321

The inferior cava enters the liver near the apex of the right lobe.

By carefully dissecting away the substance of the liver, the course

of this large vein may be followed entirely through that organ. It

extends in a nearly straight line through the dorso-lateral part of

the right lobe, and emerges from the anterior surface of the liver

as the large thin-walled vessel that empties into the heart. Just

before, or at about the time of its emergence from the liver, it is

joined by the large hepatic vein, so that that part of the inferior

vena cava which is anterior to the liver is many times as large as

that part which is posterior to the liver. This completes the de-

scription of the more important peripheral vessels of the vascular

system; and it now remains to describe the structure of the heart.

The Heart

The heart lies far forward in the body, just anterior to a line

joining the front legs. It is protected ventrally by the broad

underlying cartilages of the procoracoids and the sternum, to

which it lies so close that they must be removed with some care in

order not to cut into the pericardial cavity. The size of the heart

is moderate in relation to the size of the entire animal, and seems

to vary considerably, even in animals of the same approximate

size. It has the vitality usually seen in cold-blooded animals,

and will continue to beat for a considerable time after being re-

moved from the body, or after being filled with the injection fluid.

External Anatomy.— When seen from the ventral aspect (Fig.

14, A), it presents six main regions: the conus arteriosus, the

bulbus arteriosus, the ventricle, the right and left atria or auricles,

and the sinus venosus. These regions may be seen from the dorsal

aspect as well, if the heart be dissected from the body (Fig. 14,

B), and they will now be described in turn. Their form and rela-

tive size will vary somewhat, of course, with their state of disten-

sion at the time they are sketched. The heart from which the

figure was made, was moderately well filled with the injection

fluid, and differs considerably in general appearance from Osawa’s

figures of the heart of the Japanese salamander.

The bulbus arteriosus (B.), to begin at the most anterior region

of the heart, is a striking object, seen on removing the skin and the

322 THE AMERICAN NATURALIST [Vor. XL

cartilages of the pectoral girdle from the ventral side of the throat.

It is of a whitish color, and its walls are tough and thick. Anteri-

orly it divides to form the arterial arches of each side, and posteri-

orly it narrows suddenly to form the truncus, which connects with

it at somewhat of an angle, instead of entering exactly in the middle

line. Its ventral surface is smooth and even, while its dorsal sur-

face may be more or less grooved longitudinally, as seen in the

figure. In cross section it is elliptical, and is compressed in a

dorso-ventral direction.

The conus arteriosus (C.) is a well marked tubular structure

Fic. 14.— The heart. A, ventral. B, dorsal aspect. B., bulbus arteriosus; C.,

conus arteriosus; L., left oe L. C., left anterior vena wer Pul., pul-

onary; R., garners vessels; R. C., right vraies vena cava; S. V., sinus

venosus; V., ventricle,

leading from the anterior angle of the ventricle, and becoming

enlarged at its anterior end to form the bulbus arteriosus that

has just been described. It is unusually long, and its cylindrical

shape and tough walls make it an excellent place into which to

insert a cannula for the purpose of injecting the arterial system.

The ventricle (V.) is a thick-walled structure of a markedly tri-

angular form, especially when seen from the ventral side (Fig. 14,

A), with the apex of the triangle towards the head, where it opens

into the truncus arteriosus. Owing to the thick muscular walls

the ventricle remains smooth and of about the same size and shape

No. 472] ANATOMY OF CRYPTOBRANCHUS 323

whether it be empty or distended. It forms the right anterior

quarter of the heart, and lies somewhat ventral to the other parts

of that organ.

The left auricle or atrium (L.) forms the left anterior quarter of

the heart, and is its largest division, though on account of its thin

distensible walls this chamber may vary considerably in size. Its

walls are usually wrinkled and uneven, and its outline is more

rounded than that of the ventricle, though the entire outline cannot

be seen in either a dorsal or a ventral view, since the chamber is

partially covered dorsally by the left auricle, and ventrally by the

ventricle. At some point on its dorsal side the vein (Pul.) formed

by the union of the two pulmonary veins probably enters it, but,

on account of the very small size of this single pulmonary vein, its

exact point of entrance could not be determined with certainty,

and so has not been indicated in the figure. The size of the pul-

monary veins in the figure has been exaggerated. The anterior

edge of the left auricle lies nearer the head than any other part of

the heart except the bulbus arteriosus.

The right auricle (R. A.) lies dorsal and posterior to the ven-

tricle and the left auricle, so that in a ventral view of the heart

only the posterior half of this chamber shows. Owing to its very

thin walls and to the large opening of the sinus venosus it has no

very definite shape. It is depressed in a dorso-ventral direction,

and its greatest diameter is from side to side. Into its antero-

lateral corners open the right and left anterior vene cave (R. C.,

L. C.), while posteriorly it is separated by only a slight constrie-

tion, externally, from the sinus venosus which in turn is continued

ack as the posterior vena cava. Extending longitudinally across

the dorsal wall of the right auricle, and closely attached to it, is

the pulmonary vein (Pul.), formed by the union of the two small

veins from the lungs.

The sinus venosus (S. V.) is merely the enlarged anterior end

of the posterior or inferior vena cava. Its walls are extremely

thin, and its size and shape will depend upon the amount of fluid

it contains. Blood vessels to supply the walls of the heart may

be seen at several places, and are shown in the figure at R.

324 THE AMERICAN NATURALIST [Vor. XL

LITERATURE

BETHGE, E.

'97. Das Blutgefässsystem von Salamandra maculata, Triton teniat-

tus, und Spelerpes fuscus. Zeitschr. f. wiss. Zoöl., vol. 63, pp.

680-708, pls. 42-43.

CHAPMAN, H. C.

'93. Observationson the Japanese Salamander, C. maximus (Schlegel).

Proc. Acad. Nat. Sci. Phila., pp. 327-333, pls. 5-7.

Ducks, A.

'84. Recherches sur l'ostéologie et la myologie des batraciens, etc.

Paris.

GOoETTE, A.

"16. Entwickelungsgeschichte der Unke. Leipzig.

Zur Anatomie der Pipa americana. Zoöl. Jahrb., Abt. j. Anat.,

vol. 7, pp. 629-647, pls. 37-38.

Har, ©, P.

’90. The Skeletal Anatomy of Amphiuma during its Earlier Stages.

Journ. Morph., vol. 4, pp. 11-34, pl. 2.

HocHSTETTER, F.

':88. Zur Morphologie der Vena cava inferior. Anat. Anz., vol. 3,

pp. 867-872

HocnsrETTER, F.

’88. Beiträge zur vergleichenden Anatomie und Entwickelungsge-

schichte des Venensystems der Amphibien. Morph. Jahrb.,

vol. 13, pp. 119-173, pls. 2-4.

HocHSTETTER,

'93— '94. CASES des Venensystems der Wirbeltiere. Ergebn.

d. Anat. u. Entwickelungsgesch., vol. 3, pp. 460—489, 24 figs.

HUMPHRY.

’71. The Muscles and Nerves of the T japonicus. Journ.

Anat. and Physiol., vol. 6, pp. 1-61, pls. 1

Hvxıey, T. H.

"4. On the Structure of the Skull and of the Heart of Menobranchus

lateralis. Proc. Zoöl. Soc. London, pp. 186-204, pls. 29-32.

Hyrtt, J.

'65. Cryptobranchus japonicus. Vindonae.

Kıngsgury, B.

'95. The ee Line System of Organs in some American Amphibia,

and Comparison with Dipnoans. Proc. Amer. Micr. Soc., vol.

17, pp. 115-157, pls. 1-5.

No. 472] ANATOMY OF CRYPTOBRANCHUS 325

v. KLINCKOWSTRÖM, A.

'904. Zur Anatomie der Pipa americana. Zoöl. Jahrb., Abt. j. Anat.,

vol. 7, pp. 647-667, pls. 39.

LANGERHANS, P.

’73. Notiz zur Anatomie des Amphibienherzens. Zeitschr. f. wiss.

Zoöl., vol. 23, pp. 457-459, pl. 25

McGrecor, J. H.

'96. Preliminary Notes on the Cranial Nerves of Cryptobranchus

allegheniensis. Journ. Comp. Neurol., vol. 6, pp. 45-53.

MECKEL, J.

18. Ueber das Zungenbein der Amphibien. Deutsch. Arch. f. Physiol.,

vol. 4

Mivart, ST. GEORGE.

'69. On the Myology of Menopoma allegheniensis. Proc. Zcól. Soc.

4-271.

'69a. On the Myology of Menobranchus lateralis. Proc. Zoöl. Soc.

London, pp. 450-466.

Mivart, St. GEORGE.

"10. On the Axial Skeleton of the Urodela. Proc. Zoöl. Soc. London,

pp. 260-278.

Murray, J. A.

'97. The Vertebral Column of Certain Primitive Urodela. Anat.

Anz., vol. 13, pp. 661-664, 3 figs

Osawa, G. :

:02. Beiträge zur Anatomie des japanischen Riesensalamanders.

Mitteil. a. d. med. Facultät d. kaiserl. Univ. Tokio, vol. 5, pp.

1-207, pls. 11-54.

Ossory, H. F.

’84. Preliminary Observations on the Brain of Menopoma. Proc.

Acad. Nat. Sci. Phila., pp. 262-274, 6 pls.

Osporn, H. F.

'88. A Contribution to the Internal Structure of the Amphibian

Brain. Journ. Morph., vol. 2, pp. 51-96, pls.

PARKER, W. K.

'81. On the Structure and Development of the Skull in the Batrachia.

Part 3. Phil. Trans. Roy. Soc. London, vol. 172, pp. 1-266,

pls. 1-44.

Reese, A. M.

:04. The Sexual Elements of the Giant Salamander. Biol. Bull.,

vol. 6, pp. 220-222, 3 figs.

Reese, A. M.

:05. The Eye of Cryptobranchus. Biol. Bull., vol. 9, pp. 22-26, 1 fig.

SEYDEL, O.

'95. Ueber die Nasenhóhle und das Jakobson’sche Organ der Amphi-

bien. Morph. Jahrb., vol. 23, pp. 453-544, 22 text figs.

326 THE AMERICAN NATURALIST [Vor. XL

STRONG, O.S.

'95. The Cranial an of Amphibia. Journ. Morph., vol. 10, pp.

101-230, pls. 7-1

WIEDERSHEIM, R.

'97 POA Anatomy (translated). London.

WILDER,

' 1. A Uodtribution to the Anatomy of Siren lacertina. | Zoól. Jahrb.,

Abt. f. Anat., vol. 4, pp. 653-695, pls. 39-40.

Wirper, H. H

'91. Die Nasengegend von Menopoma allegheniensis und Amphiuma

tridactylum, etc. Zoöl. Jahrb.. Abt. f. Anat., vol. 5, pp. 155-

177, pls. 12-13.

Wivper, H. H.

’96. Tuga Salamanders. Anat. Anz., vol. 12, pp. 182-192, 7 figs.

(No. 471 was issued March 22, 1906.)

BERGEN’S

ELEMENTS OF BOTANY

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THE

AMERICAN NATURALIST

Vor. XL May, 1906 No. 473

APPLICATION OF DE VRIES’S MUTATION THEORY

TO THE MOLLUSCA

FRANK COLLINS BAKER

PROBABLY no work since the publication of Darwin’s Origin

of Species has produced such a profound sensation in the biological

world as the work entitled Die Mutationstheorie, by Hugo de Vries.

A perusal of that work (or, perhaps better for those not having the

time, the shorter work Species and Varieties; their Origin by

Mutation) leads the zoölogist to ponder upon the question as to

how far these theories may be used in connection with animal

forms, especially with the invertebrates. Much experimentation,

covering a long period of time, must be done, however, before

anything definite can be accomplished. De Vries spent twenty

years raising and studying primroses. The zoölogist must do

likewise and study some common forms for a long period, breeding

them under conditions conforming as closely as possible to the

natural environments of the organisms. The question of ele-

mentary species and varieties is one which would seem to have a

meaning in botany somewhat different from the use of the same

terms in zoölogy, in fact, in some of the Invertebrata (the Mollusca,

for example) there would seem to be no distinction between an

elementary species and a variety, the terms being synonymous.

However this may be, it would seem that to the Mollusca the

de Vries theory might be applied with some interesting results.

The writer would ask the question: Are not many of the varia-

tions of the Mollusca produced in the manner outlined by this

new aspect of evolution? The writer does not feel warranted

327

328 THE AMERICAN NATURALIST [Von XL

in answering this question in the affırmative, but he does believe

that the illustrations which follow are suggestive and certainly

point to some such derivation. It is not held, even by de Vries,

I take it, that the mutation theory is to supplant or take the place

of the older evolution by whose slow and gradual processes

(natural selection, survival, environment, distribution, etc.) the

present state of animal and vegetal matter has been reached, but

as an additional process in that great scheme of life.

In certain mollusks the species seem to be unstable, that is,

they have a tendency to vary, not in a given direction but in many

Fia. 1.— Lymnea palustris Müller, from Halma, en Note the wide range

of variation in the form of the shell. Enlarged.

directions at the same time. These seem to come under the head

of mutants, or sports. The fresh-water pulmonates belonging

to the genus Lymn:ea are examples of this class and every species

which has been studied in any quantity has been found to vary

in this manner. Lymnea palustris Müller (= elodes Say) is one

of the most notably variable, and its mutations are many and

marked. Fig. 1 represents a set of ten shells of this species col-

lected by Mr. L. E. Daniels in Muskag swamps, Halma, Minne-

sota. They vary from a long, narrow shell, with elevated spire

No. 473] MUTATION IN MOLLUSCA 329

(1) to a fat, robust shell, with a comparatively short spire (10).

In some specimens the whorls are flat-sided (4), while in others

they are convex, especially the last, which is very convex (3, 10).

The columella plait also varies in size and elevation and the

sutures vary in the degree of impression (compare 3, 4). Several

of these mutations, if we can so designate these variations, have

Fate Lymnaa Saar Müller, from "emm Island, Alpena, Michigan. Enlarged.

been described as species or varieties; thus 10 is Lea's nuttalliana

and 1 is Say's elodes. It will be seen that no line can be drawn

between 1 and 10 in the presence of the intervening figures. Take

away these connecting links and a very distinct variety remains.

In the Mollusca the factor of geographic variation plays a very

important part. The shells from the locality illustrated in Fig. 1

are rather small, measuring 23 mm. in length. Fig. 2 illustrates

the same species from Sugar Island, near Alpena, Michigan (col-

330 THE AMERICAN NATURALIST [Vor. XL

lected by Dr. W. A. Nason); the shells are much larger than

those of Fig. 1, and measure 30 mm. in length. It will also be

noted that the variation in this lot of shells is not so marked as in

those illustrated in Fig. 1. There is considerable difference

between the extremes but the majority of specimens conform

more or less to a single type, the large, corpulent form. A study

of several hundred specimens from each locality shows that each

lot varies a certain percentage toward a given form. In lot 1,

(Fig. 1), the variation is 75 percent toward no. 1, while in lot 2

(Fig. 2) the variation is about 60 percent toward no. 8. Without

more data to disprove it, this would seem to point to the fact that

the species of each locality varies toward a definite form. In lot

no. 1 the dominant form is palustris, while in lot no, 2 the domi-

nant form is nuttalliana.

The interesting fact in connection with all this is (and this is

where de Vries’s mutation theory seems applicable) that all the

forms illustrated will develop from the same egg capsule. ‘The

eggs laid by nudtalliana will produce narrow palustris as well as

the fat parent form, while the narrowest palustris will likewise

produce the fattest nuttalliana. May this not be an illustration,

also, of two types (although this subject is treated under ever-

sporting varieties by de Vries) which he calls poor races and rich

races. In Fig. 1, 75 percent of the progeny are palustris (assum-

ing that the parent was a palustris form) and are of the rich race,

while in Fig. 2 (as-

suming the parent to

be palustris) the prog-

eny are of the poor

form, only 40 percent

being the palustris

form. This, however,

is only hypothetical in this case. Nothing but actual experimenta-

tion can give accuracy to this phase of the subject.

In some other groups of shells the variation is along certain

definite lines and the species seem to be more stable. For example, -

among the land shells Polygyra profunda and Polygyra multilin-

eata vary in lacking or having bands, the uniform varieties being

light (albino) or dark. Polygyra tridentata varies in its aperture

1 2 5 4

Fic. 3. -7 Variation in Tavas. de EK. T dis

Walke

2. 3. nata

Lea. 4. y. bicarinata normalis Walker. n isses

No. 473] MUTATION IN MOLLUSCA 331

from no teeth through one, two, to three teeth. Some of the forms

of Polygyra may be perforate or imperforate (Polygyra monodon,

for example). In Valvata (Fig. 3) the variation seems to be still

more marked, the variant being in the number and position of the

caring; for example, Valvata tricarinata has three carine (1); var.

confusa has two carinze (2) and another variety has one carina.

So also with Valvata bicarinata, which has two carine (3) while

the variety normalis has three carinæ (4). Vivipara contectoides

is another example in point, the typical form being banded, while

a variety is without bands. These variations would seem to con-

form to de Vries’s retrograde varieties, differing from the parent

species in the absence of one or two characters. The majority of

the latter examples are true varieties, lacking some characteristics

of the type form, while the variations of Lymnza are mutations

combining most of the characteristics of the parent form. It is

to be noted, however, that these two conditions overlap each other,

so that no sharp and fast line can be drawn between them.

Some of the paleontologists have hailed de Vries's theory with

delight, for they say that it is only in the light of such a theory

that the sudden appearance of marked types in certain ancient

faunas becomes intelligible. May it not also account for the

finding of certain new species in regions supposed to have been

thoroughly explored? May it not also account for the sudden

disappearance of certain species, the mutations dying out but

the parent form still continuing? A case in point is Lymnaea

shurtleffi described from an artificial pond at Weatogue, Hartford

Co., Connecticut. This species was found in large numbers,

ER with a new variety of Planorbis (P. eireumstriatus TS

The finding of this Lymneea is thus described by Mr. Tryon: '

“The cireumstances under which this and the following species

were found are so peculiar that it is with great hesitation that I

have ventured on a description of either of them. That new

species of these shells should exist undetected in sections of the

United States which have been so well explored by assiduous

naturalists would be surprising; but in the present instance the

almost irresistible supposition is, that these species are of very

ı4mer. Journ. Conch., vol. 2, p. 112, 1866.

332 THE AMERICAN NATURALIST [Vor. XL

recent origin [italics mine] in fact, contemporaneous with that of

the body of water which they inhabit. I have looked in vain for

some evidence upon the specimens themselves of the effect of

some strong local influence. ‘The species are so distinct that they

afford no clew to a possible derivation from others.

“Tn conclusion, I present the following interesting particulars:

“Extract from a letter from the late Dr. S. Shurtleff to Isaac

Lea, Esq., Weatogue, Hartford Co., Connecticut, November 22,

1865.

“In the summer of 1860 I made an excavation some two rods

below a spring that flows about eight months in the year. The

spring comes from a neighboring hill. The overlying rock is

New Red Sandstone. From the time of the excavation till the

summer of 1864 there was water in the artificial pond. It was

dry in 1864, but I did not examine for shells, as before the excava-

tion I had repeatedly examined the spring, but never found shells

of any description.

“After my return from Pennsylvania, in September, 1865,

accidentally crossing the pond, which was dry, I noticed quanti-

ties of shells clustered in the hollows. I gathered a few and laid

them by for leisure examination; when I came to look at them

again I found L. umbrosa, as I supposed, as well as a non descript

species. I immediately went to the pond and secured all the

Lymneeans I could find— some alive and many dead; and, fearing

the dry season would destroy them all, I put many of the living

shells into a pond that I have since made, that will never dry up.

I may have collected 50 specimens of L. wmbrosa (?) and of other

specimens a half-pint.

“How these shells came into the pond is as much a matter of

surprise to me as it is to you. I have no knowledge that there

was ever a shell put into the pond.

“One fact more. The spring and pond are perfectly isolated,

as the overflow disappears at the edge of a sandy plain in less than

ten rods from its fountain head, and there is no stream of perpetual

running water within one mile of it. The Farmington River is

about a mile distant in the valley below, and here the only species

yet found are Lymnea columella Say, Physa heterostropha Say,

Planorbis bicarinatus Say, Vivipara decisa Say, Unio complanatus

Solander, and Unio radiatus Lamarck.

No. 473] MUTATION IN MOLLUSCA 333

“The pond is two hundred feet above the bed of Farmington

River.”

Tryon says: “Besides the above two species I found a single

specimen of Lymnæa umbrosa Say, and several of L. desidiosa

Say.”

From the foregoing account it would appear that shurtleffi

(Fig. 4) was an offshoot (or mutant, if we apply the de Vries

theory) of umbrosa! (= elodes = palustris), that being the only

other species present (save desidiosa, which belongs to quite

another group of Lymnsas). It may be thought by some that

shurtleffi might have been produced by un-

favorable conditions, but as the shells, one

of the original lot of which was recently

examined by the writer, are perfect and not

distorted, this could hardly have been the

case. All the evidence points to the con-

clusion that shurtleffi is a new species evolved

or given off from palustris. The short, acute

spire, subcylindrical, compressed body whorl,

the partly open umbilicus, and the long and

narrow aperture are the principal character-

istics of the new species.

The foregoing remarks are not made with

the idea of fastening the mutation theory

upon the Mollusca, but only to call attention

to these apparently analogous cases of mutation and variation

to the end that other zoölogists may take up the matter and by

experimentation and by the study of abundant material from

various localities gather a large amount of data bearing upon

this theory as applied to the Mollusca.

While the mutation theory seems to fit in very nicely in explain-

ing the very large amount of variation in the fresh-water pulmon-

ates, we must not be too hasty in applying this new theory, founded

as it is upon plant variation, to animal life. Dr. J. A. Allen, in a

necticut. Enlarged,

‘Umbrosa is placed by some conchologists in the synonymy of refleza. I

have examined the type specimens in the Philadelphia Academy and they

are good examples of elodes.

334 THE AMERICAN NATURALIST [Vor. XL

recent number of Science! calls attention to the danger of accepting

this hypothesis without more conclusive proof, and I cannot do

better than to close this communication with his remarks. He

says: "While the mutation theory may be a good hypothesis to

consider in respect to these peculiarly unstable groups of birds,

it must be noted that the method of their origin and the results,

as now known, are very unlike the methods and results of muta-

tion in plants, as made known by de Vries. ‘The facts and condi-

tions are not to any great extent parallel. Instead of the resultant

‘mutants’ remaining constant and breeding true, as in the case of

primroses, they are in this case unstable and are believed to inter-

breed freely with each other and the parent stock.”

I am indebted to the following gentlemen for assistance in the

preparation of this paper: Dr. Henry A. Pilsbry, Academy of

Natural Sciences, Philadelphia, Pa., for the loan of a type speci-

men of Lymnea shurtleffi; Mr. L. E. Daniels, La Porte, Indiana,

for specimens of L. palustris from Minnesota; Dr. W. A. Nason,

Algonquin, Illinois, for specimens of L. palustris from Michigan;

and Mr. Frank M. Woodruff, Chicago Academy of Sciences, for

making the excellent photographs which illustrate this atum

CHICAGO ACADEMY or SCIENCES

1“ The Probable Origin of Certain Birds.” Science, n. s., vol. 22, p. 431,

1905. : i ;

NOTES ON THE GENUS LEPTOPHRYS

WILLIAM A. KEPNER

In THE year 1869 Hertwig and Lesser published in the Archiv

für mikroskopische Anatomie (Supplement zu Banden 1-8) an arti-

cle entitled “Ueber Rhizopoden und denselben nahestehende

Organismen.” On page 57 of this volume they describe a new

genus which they name Leptophrys. The following is their diag-

nostic description of this genus: ‘Body variable in form, sheet-

like with processes put out, pointed and unbranched pseudopodia,

which are chiefly found at the end of the processes; the paren-

chyma is filled with small non-contractile vacuoles nearly equal

in size"; and though they saw but three bodies in a single indi-

vidual which they took to be nuclei and failed to see nuclei in any

other specimens, they add: “Nuclei in great number." The color

or its absence in the “ pearl-like" granules served them as a basis

for distinguishing the two species, L. cinerea and L. elegans.

In December, 1904, I discovered in some. water taken by Mr.

William G. Lapham from an oozy bank near Afton, Virginia, a

large Vampyrella-like specimen (Fig. 1), which except for the ab-

sence of nuclei and the variable size of the vacuoles answered in

detail to Leptophrys elegans. In size the creature would cover a

circular surface whose diameter was 80 micra.. It was very active,

constantly changing its form laterally, though dorso-ventrally it :

maintained a film- or sheet-like structure which was about 5 or 10

micra thick. The protoplasm was highly vacuolated by non-

contractile vacuoles. The degree of vacuolation varied at dif-

ferent stages of vital activity. When most highly vacuolated the

vacuoles approached equality in size. ‘The body was also marked

with numerous, more or less equal, *pearl-ike" granules. The

rather short, unequal, pointed, and unbranched pseudopodia were

given off from the margin of the body. They contained no vacu-

oles nor refractive granules. When vacuoles and refractive gran-

ules were pushed out they formed processes which might bear one

or more pseudopodia. Most of these were given off from an ab-

solutely transparent marginal layer of protoplasm. Subsequently

335

rVor. XL

THE AMERICAN NATURALIST

336

ALE

vem

noose ee en nen

: «IS : š rien

Mage Ga : :

eter €

(einen nme.

Thes

Tus

uius

bs ns -

(u^

po sg

tetur eee nat

Fie bos Scale: 1 mm. — 1 micron,

No. 473] NOTES ON LEPTOPHRYS 337

numerous specimens were found which did not show such a clear

margin. Many specimens were seen which were quite free from

food particles, but no staining of these would bring out a differen-

tiation between the refractive granules and what might have been

taken for nuclei. The figure of Hertwig and Lesser leads me to

suspect that what they had taken for nuclei with central “nucleoli”

were monads ingested as prey. It is unfortunate that they did not

state how they determined these bodies to be nuclei.

Locomotion is effected by a more or less active amoeboid move-

ment. An active large individual tosses itself about very much as

a cloud of smoke is distorted by a current of air. On the other

hand the movement may be slow and deliberate.

The large individual represented in Fig. 1, took in as food dia-

toms, desmids, and what may have been several Infusoria. On

March 22, 1905, in a bottle, that since March 12 had contained

living Chlamydomonas reticulata, I found numerous specimens

some of which belonged to L. cinerea and others which I had to

place under the species L. elegans. They were feeding upon the

Chlamydomonads. In one case I saw an individual that had

ingested at least 25 Chlamydomonads. These flagellate forms

after being ingested were greatly reduced in size. One specimen

was found which had ingested a single Navicula sp. ‘The inges-

tion of food was carefully observed. It was done, so far as could

be seen, just as an Amoeba envelops its food, but the closing of the

ectosare about the prey in the fashion of an iris diaphram could

not be made out. The food appeared to be partially digested

while the animals moved about. This inference is based upon

the broken-down appearance of the ingesta. The food is eventu-

ally assembled into a common vacuole more or less centrally dis-

posed.

Some time after the animal has gorged itself with food, or formed

a central common vacuole of food, it withdraws its pseudopodia

and enters into an encysted condition. Numerous cysts have

been seen and studied. A single individual has been observed

ingesting food and was followed through its complete encystment.

From the time when the animal had quieted down and ceased to

ingest food to when it left the cyst, a period of five hours had elapsed.

The cyst varies in size and shape, depending upon the size of the.

338 THE AMERICAN NATURALIST [Vor. XL

animal and the amount and form of the food. When the food

vacuole contains rounded bodies like Chlamydomonads the cyst

is spheroidal in form (Figs. 5 and 6). One animal was seen

encysted about a single Navicula sp. In this case the cyst was

oval (Fig. 4); in Fig. 2 is shown an encysted individual which had

”,

eh M

Figs. 2 and 3.— Scale: 1 mm. = 1.18 micra.

a food vacuole of numerous long bodies that determined an elon-

gated: cyst. . The animals vary greatly in size. Fig. 1 represents

an individual that is somewhat larger than the average; the cysts

of course are found to vary as greatly in size.

Upon encystment the animal is colorless or nearly so (Fig. 5).

During encystment a color is assumed in some cases, which seems

to depend upon the character of the food that is being digested.

No. 473] NOTES ON LEPTOPHRYS 339

In cases where Chlamydomonads were being digested and reduced

in size the food lost its green color and gradually became dark

brown (Figs. 5, 6). As this proceeded the refractive granules

and the protoplasm took on a brownish tint, which was evidently

due to products of assimilation (Figs. 6, 7). On the other hand

in two observed cases where diatoms, desmids, and Infusoria were

being digested, no coloration was noted (Figs. 2, 4). During the

early part of the encystment the vacuoles are not conspicuous. As

the end of the encysted condition approaches the vacuoles become

more prominent. The cyst may rupture at one, two, three, or

four places, and the contents escape through the clefts. In the

Fies. 4 and 5.— Scale: 1 mm. — 1 micron,

large cyst shown in Fig. 3 the protoplasm streamed out at a cleft

in the apparent upper right hand corner of the cyst. As the pro-

toplasm flowed out it broke accidentally into four greatly unequal

portions. Each part, though no two were equal in size, became

a complete individual. These daughter individuals were almost

colorless. In the forms that had been feeding upon Chlamy-

domonas the contents emerged at two, three, or four clefts in the

cyst membrane (Fig. 7). In all these cases the daughter individ-

uals came out of the cyst colored light brown. As they lived an

active life their color decreased. Beneath a single cover-glass all

degrees of coloration were easily found. The transparent ones

answered to Hertwig and Lesser's description for L. elegans. The

340 THE AMERICAN NATURALIST [Vorn XL

brown ones as they leave the cyst, I take to be their L. cinerea. In

as much as they had not seen any specimens ingest food and had

observed no encystment I am led to believe that what they studied

and described as two species were but different nutritive conditions

of individuals of the same species.

In November, 1904, Mr. Lapham observed a large colorless

Fıas. 6 and 7.— Scale: 1 mm.=1 micron.

individual divide into daughter parts of protoplasm to each of

which the food enclosures had been equally distributed. In March,

1905, I observed one of the individuals found living with Chlamy-

domonas reticulata divide into daughter forms. ‘The process was.

rather slow. It began with the formation of two fan-shaped parts,

connected by a wide neck (Fig. 8). This neck became more and

No. 473] NOTES ON LEPTOPHRYS

more attenuated until at the

end of 35 minutes there was

the merest strand of proto-

plasm connecting the two

parts, which had now moved

500 micra apart. This strand

suddenly snapped and the

fragments moved away as two

new individuals. While this

process was going on one of

the parts ingested a Chlamy-

domonas. Except for this

there was not a trace of

ingesta within the dividing

protoplasm.

These observations seem to

afford reasons for setting aside

Hertwig and Lesser's two spe-

cles, L. cinerea and L. elegans;

and the fact that, although

there was ample opportunity

to demonstrate nuclei such as

Hertwig and Lesser describe

as seen in part of a single in-

dividual, no evidence of their

presence was obtained, leads

to the conclusion already sug-

gested by Penard that the genus

Leptophrys is but a synonym

for a species of Vampyrella.

The variation in the form

of the cysts of this Vampyrella

and the two cases of binary

fission, independently observed

by Mr. Lapham and myself in

this species, are of interest.

Attention is also called to the

— "5:

i :

us S.N

4 MA uv N

Fie. Cae 1mm. pU

—

342 THE AMERICAN NATURALIST [Vor. XL

apparently accidental division of protoplasm that takes place where

there is no centralized nucleus. |

I am indebted to Mr. A. H. Tuttle, of this laboratory, for sug-

gestions of value to me in preparing this article.

UNIVERSITY OF VIRGINIA

BIOLOGICAL LABORATORY

EGG-LAYING OF CRAYFISH

E. A. ANDREWS

In crayfish, as in related Crustacea, the eggs are carried fastened

to the limbs of the abdomen during the long period of develop-

ment that precedes their hatching. As: the openings of the ovi-

ducts are upon the thorax, the eggs have to be transported some

distance to reach the abdominal limbs. It is the purpose of this

article to describe some of the activities of the female associated

with the extrusion of eggs from the oviducts, their transportation

to the limbs of the abdomen, and their fixation there.

In a crayfish in France, a species of Astacus, some of the behav-

ior of the female in laying was long since made out by Chantran

(Compt. Rend. Acad. Sci. Paris, vol. 71, pp. 43-45, 1870; vol. 74,

pp. 201-202, 1872) in his long continued and careful study of the

life history of the crayfish. His too brief statements are as follows.

The female crayfish stands up and for several hours secretes a

viscid mucus from the limbs of the abdomen. It then lies down

upon its back with the abdomen bent forward toward the open-

ings of the oviducts, in such a way as to form a sort of chamber,

in which, on the following night, the eggs were received as they

were expelled from the reproductive organs. In different females

the expulsion of eggs lasted from one to several hours. The

eggs were plunged into the mucus which, as it were, bound the

edges and the end of the abdomen to the thorax and also helped

to make the boundary of the above mentioned chamber or basket.

In this chamber there was some water as well as eggs and mucus.

All the eggs were laid at one period and rarely were any laid i in

the day time.

Observations upon the laying habits of an American crayfish,

Cambarus affinis, as published in this journal (Amer. Nat., vol.

38, pp. 165-206, 1904) showed a close agreement with the above

account. Renewed observations upon the same species in April,

1904, have added more details and verified suppositions previously

made to bridge over gaps in observation of actual extrusion and

transport of eggs.

343

344 THE AMERICAN NATURALIST [Vor. XL

The activities of the female connected with egg-laying may be

divided, for convenience of description, into four periods. First,

the preparatory cleansing of the under side of the abdomen and

thorax. This lasts four or five days and has been described in

the previous paper. Second, the period of secretion of mucus,

or “glairing” as we may call it, to be described below. Third,

the period of actual extrusion of eggs, previously inferred but

described below as actually seen. Fourth, the rhythmic alter-

nation of position of the body, or “turning,” lasting several hours

and described in the previous paper.

All these processes precede the long care of the eggs as they

hang fastened to the abdominal legs for from five to eight weeks

till they hatch, after which there is a brief period of association

of female and young before the latter scatter and become inde-

pendent.

The least well observed process is that of secreting glaire from

the glands of the abdominal appendages and sterna. It always

follows the long and very laborious cleansing of those surfaces

and immediately precedes the extrusion of eggs so that as soon

as the glaire is ready and the female properly posed, the eggs pass

out into the glaire, one period passing insensibly into the other.

At the time of secretion the female is still easily alarmed and

moreover the glaire is at first seen with difficulty as it is like water

in refraction, so that in most cases the “glairing” period escaped

observation. But as far as was made out the secretion of the

glaire took less than half an hour, though Chantran speaks of

Astacus as secreting mucus for several hours. Possibly some

of this time was taken up with “cleansing,” which has not yet

been noticed in Astacus. But if there is an actual time difference

between Cambarus and Astacus it may be due to differences in

temperature since Astacus lays in winter and this Cambarus in

spring.

The details of the activities of a crayfish observed during the

“glairing” process were in one case as follows. At first the

animal kept the same unusual attitude assumed in cleansing

itself, that is, it stood high up on its legs with the thorax and

abdomen raised far above the bottom. The abdomen was bent

forward loosely and its caudal fan reached nearly as far as the

No. 473] EGG-LAYING OF CRAYFISH 345

middle of the abdomen. The small limbs of the abdomen, the

pleopods, swung slowly back and forth with interruptions and

then, after three minutes, flapped actively back and forth. ‘Three

minutes later the crayfish gave up this attitude and crouched

down and turned slightly over to one side while still swinging

the pleopods and also making very active fanning movements

of the exopodites of the maxillipedes. After four minutes the

crayfish again stood up and swung the pleopods back and forth

for five minutes and then a faint halo of glaire was first detected

about the pleopods. The abdomen had now become bent for-

ward in a curve so that it resembled a half-closed hand and the

space so enclosed seemed filled with an almost invisible glaire.

When the pleopods inside this mass moved there resulted a jerky

movement of dirty lines where the glaire and water met at the

anterior opening of the chamber formed by the bent abdomen.

Two minutes later the animal ceased to stand up and lay upon

its left side with all the right legs high in the water, but after lying

thus for two minutes it turned onto its ventral side and crouching

prone, raised its third, fourth, and fifth legs on the left side, but

coming against the side of the dish, did not roll over onto its right

side as was expected. By this time the long continued and increas-

ing contractions of the muscles of the abdomen had flexed it so

far forward that the tail-fan reached to the bases of the second

thoracic legs, leaving only the mouthparts and the bases of the

chelee and second legs exposed to view. The pleopods were

still moving rapidly back and forth inside the glaire chamber.

Two minutes later, some of the legs on the right side were raised

and the animal seemed about to turn over onto the left side but it

returned to the ventral position. The abdomen had now become

flexed even more powerfully so that its terminal piece, the telson,

reached to the bases of the chelz, or first thoracic legs, and it was

pressed upward against the thorax so that some of the slightly

turbid glaire was forced out from between the tail-fan and the

thorax. With the abdomen thus carried forward under the thorax,

the animal remained six minutes crouching down so that anteriorly

the ventral side of the thorax was near the bottom of the dish

while posteriorly the dorsal side of the abdomen rested upon the

ttom. Then all the right legs were raised and the body slowly

346 THE AMERICAN NATURALIST [Vor. XL

swung about through 120° till the right chela came against the

end of the dish and the animal turned over onto the left side and

rested with the anterior part elevated and.the abdomen upon the

bottom. Lying thus for some minutes the crayfish made no

movements of any external organs. |The tail-fan had receded a

little but was still as far forward as the bases of the second thoracic

legs.

Two minutes later, i. e., about half an hour from the beginning

of the “glairing”” process, the continued recession of the abdomen

laid bare the bases of the third: legs and over the edge of the telson

an egg was seen in the glaire above the telson. Thus the glair-

ing period had already passed and the extrusion of eggs had been

going on. A minute later the withdrawal of the abdomen stretched

the glaire like a membrane from the edge of the telson to the region

of the anterior thoracic legs and through this veil rows of eggs

were seen issuing out from the opening of the oviduct on the base

of the third right thoracic leg. The extrusion of eggs, however,

will be described below from other more normal cases in which

the crayfish lay upon its back and not ve one side when the

eggs were extruded.

The actual extrusion of eggs was seen in six crayfish and took

place ‘in approximately the following number of minutes in these

cases: 10, 10, 13, 17, 20, 30. This is in strong contrast to the

statement of Chantran that, in Astacus, the extrusion of eggs

lasted from one to several hours. Possibly he confounded the

period of extrusion with the following period of ‘ turning ". which

may well exist in Astacus and which in Cambarus Pp several

hours.

In Cambarus as in Astacus it was very unusual for eggs to be

laid in the day time and the above six cases were seen in the day

time only from the employment of the following expedient. Cray-

fish that had finished the cleansing process were prevented from

laying by being kept all night in running water barely sufficient

to moisten them and then put into deeper water in the day time.

After two or three repetitions of this treatment some ten females

laid in the day time, several hours after being put into deep

water.

Though no crayfish laid when merely moist, one small specimen

No. 473] EGG-LAYING OF CRAYFISH 347

laid in water so shallow that the animal could not cover its back

when crouching down as close to the bottom as possible. This

female carried on some turning movements after laying and after

forty-three days the eggs, apparently all of them, hatched out,

contrary to expectation.

Some individuals, however, could not be forced to lay in the

day time even by numerous repetitions of the alternating condi-

tions. Such crayfish did not lay at all, yet when examined some

were found to have the ovaries full of large eggs. Others kept

for two months gradually resorbed the ovarian eggs. In such

ovaries the old eggs were reduced to isolated, irregular yellow

masses scattered throughout the ovary, while translucent new

and minute eggs filled in much of the space between the degen-

erated eggs.

In the cases of egg-laying observed under the above forced

conditions the extrusion of eggs followed after a thorough cleansing

of the region that then secreted copious glaire. By the bending

of the abdomen there was then formed a chamber, or basket,

full of glaire, a sort of “incubatory pouch” which received the

eggs and in which they were made fast to the pleopods. The

way in which the tail-fan expands to close in this pouch and the

part played by the glaire, or mucus, were well described for Astacus

by Lereboullet in 1860 (Ann. Sei. Nat., zoól., ser. 4, vol. 14).

Being thus provided with a basket full of glaire the female

after a few trials lies down upon her back, a most remarkable

position considering the energy with which such crustaceans

avoid it and escape from it at other times. The flexure of the

abdomen becomes so excessive that the telson is brought up as

far as the bases of the chele, or even to half cover them, and

thus the glaire is smeared over all the ventral surface of the thorax

near the oviduct openings upon the bases of the third, or middle,

pair of legs. The eggs will thus come out into a bag of glaire

and though laid under water they are not laid into the water.

The gradual relaxation of the abdomen finally uncovers the bases

of the third pair of legs so that the eggs may be seen coming out

of the oviducts. This withdrawal of the abdomen does not, how-

ever, expose the eggs to the water since the viscid glaire that has

been put upon the thorax is drawn out from the thorax to the

348 THE AMERICAN NATURALIST [Vor. XL

receding telson like an apron that covers over the eggs and prevents

them from falling out even when the female turns right side up.

This is the condition indicated in Fig. 5 of the preceding article

in this journal.

While the eggs are emerging, the crayfish is almost motionless,

lying supine with stiffly outstretched limbs and open claws as if

dead. If now removed from the water and held in the hand the

crayfish responds but little and the flowing out of eggs continues

and may be more closely watched.

The mouths of the oviducts are widely open and remain fixed

in that state when the crayfish is plunged into boiling water. It

is then seen that the oval membrane that usually covers the open-

ing is pulled outward like a curtain leaving a somewhat triang-

ular orifice bounded on the external edge by this drawn curtain

and on the median edge by the rounded rim against which the

curtain comes when it is closed. Deep inside the large orifice

opens the smaller oviduct tube full of eggs, each filling the tube

from side to side. ‘These eggs are also fixed by the heat in some-

thing of their natural irregular form. In life the eggs come out

distorted by pressure and are so soft and flowing, like liquid in

thin bags, that they mutually flatten against one another and

become indented by contact with solid objects.

The eggs generally emerged in two streams one from each ovi-

duct, but in some cases only one oviduct was used for a long time.

The rate at which the eggs came out varied from 12 to 60 a minute

on each side. With some stoppages and changes in speed some

two to six hundred eggs were laid, by different females, in less

than half an hour. Frequently the eggs came out in sets of three

flattened together and the last one of the set rounded itself off

during the brief pause before it was pushed away by the coming

out of the next set. Thus the mouth of the oviduct was alter-

nately taken up with one rounded egg and with three flattened

eggs. When the end of deposition drew near, a gradual ending

was brought about in one case by a cessation of all flow for two

minutes and then the emergence of only two eggs, the last to be

laid. When this animal was dissected an hour later the ovary

was empty save for three eggs in the posterior lobe and two in the

left oviduct and one of these slipped out of the mouth of the ovi-

No. 473] EGG-LAYING OF CRAYFISH 349

duct when the ovary was being removed. Both oviducts were

greatly distended, though for a long time only the right one had

been discharging eggs.

The glaire into which the eggs come is dense along the edges

of the abdomen and can be picked up by forceps as ‘ blobs’ that

hang down a half inch or so, supporting their weight. But the

rest of the glaire is too weak and watery to be pulled away. When

the abdomen was forcibly bent back to examine this glaire and

the female prevented from laying for a night there was no second

secretion of glaire over laying though cleansing movements were

carried on again. When the crayfish laying eggs was suddenly

put into boiling water the glaire coagulated sufficiently to form

an opaque white mass over the eggs in the posterior part of the

abdominal basket but the glaire over the issuing eggs did not

become opaque enough to hide their red color.

The transfer of the eggs from the oviducts to the pleopods

within the abdominal chamber is purely the work of gravitation.

Though the crayfish lies upon its back the abdomen is always

lower than the thorax and in some cases several legs were actively

braced against the bottom of the dish in a manner to exaggerate

this sloping of the body. In one case the animal sat propped up

at an angle of nearly forty-five degrees supported upon its short

fifth legs and upon the abdomen. Generally, however, only the

tip of one chela and one leg touched the bottom and thus gave

more stability to the animal as it lay upon its rounded back.

The deep groove between the bases of the thoracic legs favors

the backward flow of the eggs which coming from each oviduct

unite in one stream that flows along the thorax onto the abdomen

and there divides to flow right and left along the bases of the

pleopods. When, as is often the case, the animal lies with one

side higher up than the other the eggs coming out of the more

elevated oviduct drop some 6 to 8 mm. diagonally across the body

before reaching the sternal surface. In such positions also the

eggs accumulate in the lower side of the abdomen and when the

animal is taken in the hand the eggs will flow right and left in the

abdominal chamber as right or left is held lower. The glaire

is thus not dense enough to stop the movement of eggs except at

the edges of the chamber and upon the pleopods. Even after

300 THE AMERICAN NATURALIST [Vor. XL

the period of extrusion and six minutes after “turning” had

begun, when an undisturbed female was taken out of the water

many of the eggs in the chamber ran over from side to side and

tended to escape at the angle between the abdomen and the thorax

on each side. Some of the eggs were then loosely attached to the

pleopods, but when the abdomen was forcibly straightened out

and held downward many of the eggs glided off over the end of `

the telson.

Though the details of action of the female at the time of extru-

sion of eggs were different in other cases the following special

case is thought to be, in the main, typical. A crayfish lying upon

its back with the telson so far forward over the thorax as to reach

to the posterior edges of the second legs showed no movements

of any organs for a minute and then only a slight motion of the

antennules and of some legs. After four minutes more there

were some slight movements of the third legs and of the left chela.

'The right chela rested upon the bottom of the dish and so held

the animal in more stable equilibrium. By this time the slow

relaxation of the abdomen had let the telson glide so far back

that the bases of the third legs were nearly uncovered. Three

minutes later by looking in under the telson one could see eggs

coming out of the openings of both the right and the left oviducts,

which openings are upon the bases of those legs.

Where the tail-fan had been over the thorax, as far forward as

the chelze, there was left a layer of glaire. On counting the eggs

in the issuing streams, still three minutes later, they seemed to

come out at the rate of one a second on each side. The only

movements of the animal were a temporary fanning motion of an

exopodite near the mouth. But five minutes later the animal had

turned to lie with the left side somewhat elevated and the eggs

were seen falling out of the oviduct of that side across the body

then to glide back into the abdominal basket. A minute later

they were coming out at the rate of ten in sixty-five seconds, in

groups of two or three at one jet and then an interval before the

next row of two or so. In another minute there were signs of

life in the rapid fanning of exopodites on the left of the mouth,

which continued for a minute, nearly stopped, and then started

again. After a minute more there were added a rolling of the

No. 473] EGG-LAYING OF CRAYFISH 351

entire body onto an even keel and then a violent struggling of the

legs as if to turn the body over into the normal prone position.

Eggs were still seen in the mouths of the oviducts, two on each

side. In this struggle to regain the ventral position the left side

was down for a minute and then the right for a minute when the

right going under and the left uppermost the animal got onto its

ventral side. It then stood thus, on its legs with ventral side

down, for two minutes with only slight movements of two or three

legs. Immediately after this brief rest the “turning” movements

began. This would no doubt have gone on for several hours

but it was checked by interference after six minutes during which

time there were fairly regular alternations of pose, this animal

lying down first upon its left side and next upon its right.

It is in these turning movements that always follow the extru-

sion of eggs, that the eggs become fastened to the pleopods, so-

that when the female a few hours after the eggs have come out,

for the first time straightens out the abdomen and the glaire is

seen only as shreds hanging from the edges of the abdominal

terga and from the tail-fan, the eggs do not fall into the water

but henceforth hang suspended from the pleopods, till hatched.

While fastened to the pleopods the developing eggs are protected

by the female and also aérated by special movements of the pleo-

pods which are the more energetic the more the water tends to be

stagnant or poor in oxygen. In all probability eggs not attached

to the pleopods would never develop, in nature, and this attach-

ment seems an essential part of the life history, here, as in many

other Crustacea. ài

Just how the fastening of the eggs takes place is by no means

clear. A microscopic examination of the so called "cement

glands" upon the sterna and all the six pairs of appendages of

the abdomen showed that in Cambarus, just as in Astacus, these

glands contain the material from which the “glaire” is made.

The same reasons that led Lereboullet (l. c.) and later Braun

(Arb. zoöl.-zoöt. Inst. Würzburg, vol. 2, 1875) to believe that in

Astacus this secretion fastened the eggs to the pleopods, apply in

Cambarus and there is little doubt that this glaire plays the most

important part in fastening the eggs. However, the remarkable

fact that in both these crayfish as in crabs the eggs are fastened

352 THE AMERICAN NATURALIST [Vor. XL

almost exclusively to hairs upon the pleopods and upon the sterna

calls for explanation. In crabs Williamson (22d Ann. Rep.

Fisheries Board for Scotland, 1904) has recently described special

hairs upon the pleopods as piercing the outer egg-case and liber-

ating an adhesive substance contained between the inner and

outer part of the egg-case. His idea is that the eggs are first

impaled in a row upon a hair, as upon a skewer, and subsequently

fastened to the hair by the collapsing of the pierced outer egg-case

and by the adhesive material contained within it. As Williamson

sought to extend this view to the lobster and other Macrura, the

crayfish, Cambarus, was reéxamined in April, 1905, to see if this

view would apply here, but no evidence of such skewer action of

hairs was found though on the other hand no absolute refutation

of such a view was obtained.

In Cambarus affinis preserved eggs have in the ovary a case

about 4 & in thickness as seen in optical section. When they

leave the enveloping cellular follicle and are laid and for at least

five hours afterwards, they have the same thickness of case but

twenty-three hours after laying the case was (observed as above)

2 u thick. In live eggs there is a remarkable change in elasticity

accompanying this change in thickness of case. While the fresh-

laid egg glides along like a liquid drop flattened and deformed by

every contact and scarcely held together by its delicate case, the

egg thirty-six hours afterwards is a tensely spherical ball, which,

dropped nine inches onto a table, rebounds five inches and con-

tinues to bounce up and down five or six times before coming to

rest. 'lhis great elasticity was noticed in Astacus eggs also, by

Lereboullet. Such eggs, however, are normally hung to the

pleopod by peculiar stalks. Each egg has its separate stalk and

this is of elastic material comparable to the egg-case.! When

this stalk was pulled out to four or five times its length, to ten

times the diameter of the egg, it flew back like a rubber band, as

soon as released. :

These stalks are not formed until a little while, 15 minutes or so,

after the eggs enter the abdominal chamber and at first they are

‘In a few cases an egg had two stalks with a ribbon-like connection over

the surface of the egg.

No. 473] EGG-LAYING OF CRAYFISH 353

exceedingly delicate, soft, wide, flat bands. ‘These are at first

very short and only slowly become as long as the diameter of the

egg, subsequently to become many times that and hard and narrow

and twisted. In this latter state they remain after the egg hatches

and connect the empty egg-case with the pleopod and are even

then a means of salvation for the young.

Near the egg the stalk expands as a rounded tent, or bell-like

membrane the edges of which are fast to the egg-case over a

rounded area about one third the diameter of the egg. Optical

sections indicate that the stalk continues by this membrane over

the egg to make its thick elastic outer case while the thin inner

case is the only one near the egg over the area covered by the bell.

At this place only there seems to be a liquid separating the inner

case from the walls of the bell. The stalk seems hollow for some

distance up from the bell and one is led to infer that each egg is

slung in a bag the closed mouth of which, when drawn out, forms

the stalk. The stalk and bell look like glass, but have longitu-

dinal creases that simulate a fibrillation. The other end of the

stalk is continuous with a flat mass that binds together many of

the plumose hairs along the side of the pleopod. In fact, these

hairs seem rather completely invested in a secretion which holds

them all imbedded in a flat mass on each side of the pleopod while

from the edges of this mass hang out the egg stalks at intervals,

every five or six hairs having their investment continued out as a

free stalk for an egg. The stalks are like a fringe from a curtain

in which the hairs are fixed; but many stalks arise from the flat

sides of the curtain.

The structure of the stalk when magnified four hundred diam-

eters is homogeneous on the outer surface but within is a clear

matrix full of vesicles about 1} » in diameter and elongated in the

length of the stalk as if by the stretching of the matrix. When

broken, in its early stages, the jagged edges of the stalk round off

slightly as if somewhat paste-like.

Some facts that seem to increase the difficulty of applying

Williamson’s view to Cambarus are the following. One female

was found in which the sterna and pleopods of the first somite

were not clean and these alone had no eggs attached to their hairs

so that the painfully laborious process of cleansing seems necessary

354 THE AMERICAN NATURALIST [Vor. XL

for attachment of eggs, and this is more readily reconcilable with

the idea that a secretion flows out over the cleansed surface to

fasten the eggs than with the idea that the hairs puncture the egg-

case and so liberate the material for fixation.

The “perivitelline space” which is held by Williamson to con-

tain the adhesive material in crab’s eggs seems to exist in Cambarus

as the result of strong, abnormal osmotic changes only, which

may accumulate liquid between the inner and the outer parts

of the egg-case, when for instance an egg is plunged into stròng

Flemming’s liquid this may accumulate in local blisters of the

outer membrane.

Ovarian eggs were not ick unless allowed to dry upon the

surface when they, either with or without the enclosing cellular

follicle, stuck to a needle and might be pulled up into club-shaped

drops that then sprung up to hang as bulbs connected to the needle

by a minute stalk.

The glaire, however, sticks slightly to dishes and to a knife

and when eggs were taken out of the glaire from the front part

of the abdominal chamber where they had not yet made stalks

(though others in the back part had done so) and put into a watch

glass of glaire, they stuck together more firmly than when left

in water. The connection of these eggs with one another after

48 hours was by delicate fibers something like early stages of egg

stalks and such eggs after fifty-eight hours were elastic so that

they rebounded five or six inches when dropped nine. Thus in

glaire the elastic case and something like a stalk were made when

isolated from pleopods and hairs. Again, eggs broken off from

very young stalks and left in moist air adhered together very firmly

and also to a dead pleopod. These facts seem more readily ex-

plained by the action of the glaire than by an assumed early

pricking of the hairs.

A microscopic examination of the material that binds the plu-

mose hairs together, made some hours after the eggs were laid,

showed that in some places this mass was a dense, clear, highly

refracting sheet, moving and breaking under pressure like a stiff

jelly, and identical with the stalks of eggs, while in other places

the material on the hairs was a milky gray matrix that rounded

itself off like a viscid fluid when broken and was full of droplets

No. 473] EGG-LAYING OF CRAYFISH 355

like those inside the cement glands. It may be that the secreted

glaire passes from the latter state into the former.

The glaire itself resembles the stalks in being a clear matrix

full of droplets that elongate when the glaire is stretched but while

some of the droplets are 14 X 124 y others.are as large as 374 X

112 # and many are compound emulsive drops of 12 to 25 y.

Glaire and egg-stalk are thus not identical.though the stalk might

well arise from glaire matrix.

Without, then, imagining any special action of the hairs we

may suppose that the eggs become fastened to them because they

are smeared with the densest secreted matter from the pleopod

glands. All the surfaces having been made scrupulously clean

the secretion can spread over the hairs as they hang like feathers

in the water and. as the glands along the pleopod are segmentally

or interruptedly arranged, the hairs may well be stuck together

in small clusters or brushes of denser glaire separated by ‚more

watery glaire. When the eggs roll down along these brushes

smeared with adhesive glaire they may stick to them as the brushes

stick to one another. all along the side of the pleopod. Once

stuck and more or less buried in the glaire on the hairs the pull

of their weight will drag out enough glaire to make a stalk., That

more eggs stick to the hairs than to the body of the pleopod may

be largely a matter of relative area.

Some eggs that were loose in the abdominal chamber when the

rest had stalks, some hours after being laid, presented the follow-

ing peculiar appearance upon one side. A rounded area agreeing

with the size of the bell of a stalk was thickly set with minute drops

on the outside of the outer egg-case while fine threads inside this

case suggested that some filose, or else secretional activity of the

egg might have been going on over this area through pores in the

egg-case. As was known to Chantran, each egg has a large polar

area and it seems possible that special activities of the protoplasm

there may be concerned in localizing the attachment of the egg

to the glaire on the hairs and aid in determining the bell-like area

of the stalk.

356 THE AMERICAN NATURALIST [Vor. XL

SUMMARY

The egg-laying habits of Cambarus affinis are closely similar

to those of Astacus, as far as the latter have been described.

In Cambarus there are four periods of activity: cleansing,

glairing, extrusion, turning.

'The transportation of the eggs from the oviducts to the abdom-

inal appendages is accomplished by gravity when the female

places herself in special positions.

The activities of the female include a prolonged use of special

tools to cleanse the surfaces later covered by the secretions of the

" cement glands," a long continued maximum contraction of the

abdomen, a habit of lying supine and externally inert during

oviposition, and a long rhythmic alternation of poses associated

with the fastening of the eggs to the abdominal appendages. After

this follow the weeks of aération and care of the eggs till they

hatch.

While the ultimate analysis of the factors concerned in fastening

the eggs to the abdominal hairs awaits future investigations the

secretion of the “cement glands" seems of chief importance

though local activities of the egg may possibly play a part.

BALTIMORE, Mp.

SOWERBY’S WHALE ON THE AMERICAN COAST

GLOVER M. ALLEN

A CENTURY has now elapsed since Sowerby's whale (Mesoplodor

bidens) was first made known to science by James Sowerby (’04)

in his British Miscellany. During this period barely more than two

dozen additional specimens have been recorded and these have

more often been to a greater or less extent imperfect. Flower

(72) in his account of the genus, listed but ten specimens of this

species known by him to be at that time preserved in the museums

of the world. Seven of these ten specimens were represented by

skulls only, while of the three others more or less of the skele-

ton was saved. Turner (’89) gave the number of known records

for the occurrence of this whale as nineteen, and a few more

specimens have since been made known, so that the general char-

acters of the species are now fairly well ascertained.

At the time of Turner’s writing (1889) but two examples of

Mesoplodon had been recorded from the western side of the

North Atlantic. The first of these was stranded on Nantucket

Island, Massachusetts, in 1867 (Agassiz, 68), and its length is

recorded as 16 feet, 3 inches (J. A. Allen, ’69, p. 205). The sec-

ond American specimen was captured on. March 28, 1889, at

Atlantic City, New Jersey, and was secured by Dr. F. W. True

for the United States National Museum (Turner, ’89, p. 13).

Nothing further was known of the species in American waters

until 1898, when a young female was found dead on the coast at

Annisquam, Massachusetts, in August. Its skeleton was obtained

by the late Professor Alpheus Hyatt for the museum of the Boston

Society of Natural History. Save for a brief mention (Hyatt, ’99)

this specimen has not been reported upon.

I am indebted to Mr. Thomas Barbour, of New York City, for

the privilege of recording a fourth American specimen and the

twenty-sixth hitherto known. Mr. Barbour has very kindly writ-

ten out the following notes respecting this interesting capture.

“On the 22d of July, 1905, a large specimen of Mesoplodon

357

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[Vor. XL

RICAN NATURALIST

AME

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No. 473] SOWERBY’S WHALE 359

bidens became entangled in the pound-nets about a mile offshore

from North Long Branch, New Jersey. It was rather exhausted

when found, and was towed with some difficulty by two large

power pound-boats to the beach, where it was secured by a rope.

It soon died owing to injuries received during its capture.

“The total length of the specimen was said by the fishermen

who measured it, to have been 22 feet. The coloration was very

peculiar. The entire upper surfaces were slaty blue-black, the

lower surfaces somewhat lighter. The sides and belly were dotted

with numerous white spots, each varying from one to three or four

inches in diameter. On the throat these patches became more or

less confluent and very irregular in outline.”

With some difficulty, Mr. Barbour succeeded in having photo-

graphs of this animal taken, two of which are here reproduced.

The first of these (Fig. 1) shows the whale lying on its left side

with the ventral portion toward the observer. ‘The spindle-shaped

form of the body, the small pectoral limb, and the beak-like snout

are fairly well seen. As the anterior part of the animal’s body was

shaded by a canvas awning, the light spots and irregular throat-

markings are distinctly seen in the photograph without’ the addi-

tion of light areas due to reflection, such as sometimes appear in

photographs of parts taken in direct sunlight. The two diverging

gular sulci are very well shown at the right-hand end of the figure,

and are clearly not confluent at their anterior inception. One of

these sulci (the lower in the figure) seems to be open, as though

stretched apart by the dragging of the left side of the head. Fig.

2 is a view of the top and right-hand side of the head. The single

crescentic blowhole with its extremities directed forward, is seen

at a; what appears to be the right eye is seen at b. The very

small mandibular tooth (c) is seen barely projecting from the

gums and its small size indicates that the animal was probably a

female. The lower jaw is clearly longer and broader than the

upper, and a slight groove or gutter can be made out at the corner

of the mouth.

The skull of this specimen was secured at considerable trouble

by Mr. Barbour, and presented by him to the Museum of

Comparative Zoölogy where it is catalogued as no. 7301. The

mandibles and the rostral portion, however, were subsequently

destroyed by an unfortunate accident.

360 THE AMERICAN NATURALIST [Vor. XL

It will be of interest to bring together a few notes on the Anni-

squam and the Long Branch specimens for comparison with other

recorded observations on this species.

A considerable variation in the color seems apparent from the

accounts of various authors, especially in respect to that of the

Fic. 2.— Mesoplodon bi bidens; North Lun Branch, New Jersey. Top of head. a, blow-

hole; b,right eye; c, tooth. From photograph loaned by Mr. Thomas Barbour.

under parts. Turner (’89) summarizes briefly the descriptions

given up to that time and concludes that there **can be no doubt

. .that this animal is not of the deep black colour on the dorsum

which one sees in Hyperoodon, but that the dark hue is dashed

with a bluish tint, so that one may describe the prevailing colour

of the back as dark bluish-gray or bluish-slate colour. ‘The grey

or whitish, almost circular spots. ...are obviously also character-

istic markings of the skin. ‘The belly is not white but of various

shades of grey, dashed perhaps with a bluish tint." Southwell

and Harmer (793), however, describe the female stranded at Nor-

folk, England, Dec. 18, 1892, as of a uniform black color, "not

appreciably lighter on the belly than on the back," with a “ per-

ceptible bluish tint on the skin in a good light." They note also

No. 473] SOWERBY'S WHALE 361

the light streaks and blotches “most numerous on the side and

ventral surface." The large fetus contained in this specimen

was a male and had the under parts “white.” W. Rothschild

(93) accordingly suggests that it may prove in this species that

the males have the belly white, while the females have this region

of much the same color as the back and sides, save for the light

blotches already mentioned. The Long Branch female seems to

be of this latter type of coloration. Grieg (98) found that the

male taken at Karmó was colored much as Rothschild describes,

with the back a blue-gray becoming lighter on the belly, which

was nowhere pure white but tinged with reddish. The clear color

of the belly extended from the gular folds to the genital opening,

and there were none of the roundish circular spots to be discovered.

Evidently the coloration was much like that of the Havre specimen

figured by Dumortier (39). Most of the recorded specimens,

however, have not been examined while in a fresh condition by a

trained naturalist and the few descriptions of the external colora-

tion are insufficient to settle the ip: of a sexual dimorphism

in this respect.

Regarding the Annisquam specimen, no color notes were taken,

but from a few small photographs in the possession of the Boston

Society of Natural History, it appears evident that the ventral por-

tion was of a lighter tint, and im one of the views a few oval whitish

spots are seen on the side a trifle behind the middle portion of the

body. Another view shows the convexity of the posterior margin

of the flukes at the median point as well as the prominent dorsal

fin. The lower jaw protruded slightly beyond the upper. Meas-

urements of this specimen, as noted by Professor Hyatt, are as

follows: total length, 12 feet, 2 inches; from anus to bight of flukes,

3 feet, 4 to 6 inches; across the flukes, 3 feet, 1 inch; from tip of

rostrum to angle of mouth, 1 foot, 14 inches. The gular furrows.

were noted as about 10 inches long and from 1 to $ an inch deep.

The bones of the Annisquam specimen were macerated and

cleaned, and are now preserved in the collection of the Boston

Society of Natural History. The skeleton presents several points

of considerable interest and through the kindness of Mr. Charles

W. Johnson, the curator of the Society’s museum, I have been

enabled to make the following notes.

The skull shows the specimen to have been rather immature as

362 THE AMERICAN NATURALIST [Vor. XL

the sutures are largely unclosed; moreover, the rostral cartilage

had not ossified so that the thin overarching premaxille of the

rostrum form a long tube nearly closed dorsally except for a slight

space where these bones do not quite meet along the median line.

The proximal portions of the premaxills just anterior to a line

passing across the middle of the blowhole, are nearly flat; they

then rise almost perpendicularly to the vertex of the skull and

seem to overhang the blowholes but slightly, although this rela-

tion is somewhat obscured owing to a slight injury. The max-

illary bones slope downward from their junction with the premax-

ille to the rim of the cranium. In the Long Branch cranium,

which is that of an animal fully adult, the broad proximal portions

of the premaxille are slightly hollowed in front of the nares, and.

rising to the summit of the skull, overhang the blowhole by their

greatly thickened antero-dorsal edges. In front and at the sides

of the nares the maxillaries are elevated as much as 2.5 cm. above

the adjacent premaxillaries, so that True’s (’85, p. 586) statement

in regard to Ziphius and Hyperoödon holds good also in some

degree for Mesoplodon, namely, that “there appears to be a pro-

gressive excavation or absorption of the bones lying in the median

line of the upper surface of the beak, accompanied by introvertion

of the premaxille and a rounding off of the extremity of the beak.”

In both the Annisquam and the Long Branch skulls the right

premaxillary is slightly larger than the left and the right nasal

opening is more convex in its exterior outline than the left. In

both specimens the maxillary and the premaxillary foramina are

on practically the same line with relation to the transverse axis of

the skull, though in the Long Branch specimen the former is about

1 cm. behind the latter. In the Annisquam specimen the max-

illary foramen is very large and its opening is below the level of

the surrounding parts. It is continued forward as a deep groove

or canal to the base of the rostrum, which is a feature practically

lacking in the skull from Long Branch. In each ramus of the

lower jaw there is a single tooth situated 25 cm. from the tip, or 3

cm. anterior to the middle point. From measurements given by

Grieg ('98) for the two Karmó specimens the large tooth was situ-

ated at one third the jaw length from the tip in each. In the Cap

Breton specimen, according to Fischer (792) the tooth was three

No. 473] SOWERBY’S WHALE 363

sevenths of the jaw length from the tip, just back of the symphysis.

The teeth of the Annisquam specimen barely projected above the

alveoli of the jaws and are sharply mucronate. ‘The basal por-

tion of each, however, is more like that of the male’s tooth in the

slightly convex posterior outline and the forward extension of the

anterior angle. Fig. 3 represents a lateral view of the tooth from

the right mandible of the Annisquam whale; its extreme length

from the point to the anterior tip is 55 em.

The Annisquam skeleton has 45 vertebra. Four of the seven

cervicals are fused. The atlas, axis, and

third cervical are firmly ankylosed through-

out, save for the lateral foramina for the

passage of the cervical nerves. The

fourth cervical is fused to the third by

the dorsal spine on the left side and by

the tip of the upper lateral process of the

same side. Its centrum, right half of the

dorsal spine (the spine is divided medi-

ally), and the remaining lateral processes

are free. This is the only case thus far

recorded in which four cervicals have

been found fused in this species for

Reche’s (:05, p. 171) statement that ai

Flower has recorded a specimen the dorsal d wa ae

spine of whose fourth cervical was fused

to the third, is a /apsus. Flower is here referring to Ziphius

cavirostris. Grieg (98) found that the first five cervicals were

united in one of the Karmó specimens but the first two only in the

other example and the same author (:04) found the first three fused

in the Rugsund specimen (1901). Fischer (792) records that in

the Cap Breton whale the first two were entirely ankylosed while

the centrum but not the spine of the third was fused with the sec-

ond cervical. Aurivillius ('86) accredits the Bohuslän (1885)

specimen with three fused cervicals. Turner (’85) found the first

two only fused in the two Shetland examples and the same was

true of these bones in the Skager Rack and the Vanholmen

specimens (A. W. Malm, ’71; A. H. Malm, '85). Van Beneden

and Gervais in their Osteographie des Cétacés give the number of

364 THE AMERICAN NATURALIST [Vor. XL

fused cervicals as three while both Van Beneden (’64) and

Dumortier (39) agree in stating that the first two only were

fused in the Ostend 1835 example. The fusion of the first two is

thus apparently the more usual condition. In the Annisquam

whale the epiphyses of the fourth and fifth cervical vertebræ and

the anterior epiphysis of the sixth cervical are fused to their respec-

tive centra, but all the other epiphyses of the vertebral column and

of the pectoral limbs are free.

The Annisquam skeleton has nine dorsal vertebrae with their

corresponding pairs of ribs, a number which agrees with that of at

least four recorded skeletons though ten pairs of ribs are recorded

in case of five others (Rugsund, 1901; Karmó, 1895; Shetland;

1885; Skager Rack, 1869; Ostend, 1835).

Fig, 4.— Sternum of Mesoplodon bidens, female, from above; Annisquam specimen.

The sternum of this specimen presents a few points of interest.

It consists of four pieces, the anteriormost of which is largest,

slightly hollowed above, and correspondingly convex below. The

three remaining pieces are nearly flat, with a deep median notch

at the anterior and posterior border of each. The most posterior

piece evidently represents a fusion of the elements of two segments

as there are articular surfaces for two pairs of ribs. Both the

Karmó specimens (Grieg, '98) had sterna of four pieces and in

each the fourth or most posterior piece seems to show articulating

surfaces for two pairs of ribs. Apparently in these the very small

sternal elements of each side corresponding to the fifth pair of ribs

fused with the next anterior sternal segment but did not fuse medi-

ally with each other, so that a deep notch is left in the posterior

margin of the last sternal piece. In the male Karmó specimen

the notch is nearly closed posteriorly indicating a medial approxi-

No. 473] SOWERBY’S WHALE 365

mation of the elements of right and left sides, and thus approaches

the condition described by Fischer (’92) for the Cap Breton

specimen whose sternum was likewise of four pieces. The fourth

was notched in front and had a central hole and a posterior notch.

This central hole evidently corresponds to the two notches that

would have been formed between the fourth and fifth sternal ele-

ments had they failed to fuse with each other. In the Annisquam

specimen this space has been quite obliterated. According to

A. W. Malm (’85) the sternum of the Skager Rack whale con-

sisted of five pieces of which the two posterior were ankylosed,

while that of the Vanholmen specimen was of four segments.

Aurivillius (’86) states that the sternum of the Bohuslän skele-

ton was of four pieces of which the last is practically like the others

save that the posterior notch is nearly closed. The sternum of

the Rugsund specimen as figured by Grieg (:04, p. 33) is likewise

of four segments, but the two elements of the fourth segment have

not united medially while that of the left side is ossified with

the next anterior piece. The 1885 Shetland whale had five sternal

pieces (Turner, ’85) but the 1881 Shetland example had four

sternal pieces only, the posteriormost of which, as in the Anni-

squam skeleton, represented a fusion of the fourth and fifth pairs

of elements (Turner, ’82). Still another variation is seen in the

Ostend specimen in which the two elements composing the fifth

or posteriormost piece are separate both from the piece next

anterior and from each other, while that of the left side is ap-

parently displaced so as to be in advance of the corresponding ele-

ment of the right side (Van Beneden, ’64, pl. 3, fig. 2). An addi-

tional point of interest in the Annisquam sternum is its bilateral

asymmetry for the right-hand element of each of the four pieces

is slightly longer than that of the left side (Fig. 4). Thus the

extreme lengths of the right-hand elements in centimeters are: 15.1;

8.4; 6.0, and 7.1, while those of the left-hand elements are 14.7,

7.9, 5.85, and 6.8 respectively. A like asymmetry is seen in

Grieg’s figure of the Rugsund specimen.

For convenience of reference, the known recorded specimens

of Sowerby’s whale are listed in the following table: —

PSonsoumonrg

THE AMERICAN NATURALIST

[Vor. XL.

Recorded Specimens of Mesoplodon bidens

Elginshire, Sootland

Havre, Fra

Sallenelles, Tua

Ostend, France

Reference

Date

1800 Sowerby, '04

Sept. 9, 1825 Blainville, ’25

Summer, 1825 Deslongchamps, ’66

Aug. 21, 1835 Dumortier, ’39

Brandon Bay, Ireland Mar. 9, 1864 Andrews, '69

orway

Nantucket, Mass.

Skager Rack

before 1866

Van Beneden, ’66

1867 Agassiz, ’68

June 15, 1869 A. W. Malm, ’71

Brandon Bay, Ireland May 31, 1870 Andrews, ’70

Scotland

Hevringholm Strand,

Denmark

Shetland

Vanholmen, Sweden

Shetland

Bohusliin, Sweden

Yorkshire, England

Firth of Forth, Scot-

and

Norfolk, England

Cap Breton, France

Atlantic City, N. J.

6, Norway

Karmö, Norway

Annisquam, Mass.

Rugsund, N orway

North Long Branch,

N. J.

Turner, 72; Flower,’72:

Feb. 3, 1880 Reinhardt, ’80-’81

Apr., 1881 Turner, ’82

Oct. 30, 1881 A. H. Malm, ’81,

May 23, 1885 Turner, S.

Aug. 6, 1885 Aurivillius

Sept. 11, 1885 Southwell in Clarke,

’86

Oct., 1888 Turner, ’89

before 1888 Van Beneden, ’88

Dec. 18, 1892 Southwell and Har-

mer, 93

Aug., 1888 Fischer, '92

Mar. 28, 1889 Turner, ’89

Aug. 25, 1895 Grieg, ’98

Aug., 1898

Nov. 14, 1901 Grieg, :04, :05

July. 22, 1905

To this list should probably be added the record of a specimen

found floating in the sea at the entrance of the British Channel

about 1840. The skull of this whale is said to be in the museum

at Caen (Flower, ’78) and on it Gervais in 1850 founded his Meso-

plodon europeus. Some confusion has also existed in regard to

1An incomplete lower jaw in the Museum at Christiania.

?An incomplete cranium without data in St. Petersburg Museum.

*Contained a large fetus.

No. 473] SOWERBY’S WHALE 367

the dates of certain of the captures. Thus Reinhardt (’80-’81)

and Van Beneden (’88) have included examples of Hyperoödon

in their lists of records; Gray (’66, p. 352) mentions a specimen

from Havre, Aug. 22, 1828, and Van Beneden (’88, p. 98) appar-

ently has quoted Gray in including this record in his paper on the

Ziphioids of European waters. It is clear, however, from the con-

text that Gray is referring to the specimen described by Dumortier

(39) and taken at Ostend, Aug. 21, 1835. Of this whale, Du-

mortier relates that it was kept alive out of water for the space of

two days but could not be prevailed upon to eat the moistened

bread that was offered it! Frequently it gave vent to loud bellow-

ings that resembled the lowing of a cow. Grieg (’98) is able to

confirm this testimony as to the possession of a voice by this species,

for he states that the female stranded at Karmé in 1895, lowed like

a calf that is being slaughtered.

It is clear, then, that Mesoplodon bidens is nani; known from

the North Atlantic only, between the latitudes of 39° N. (Atlantic

City, N. J.) and about 60? N. (Shetland). "That it is probably not

gregarious has been pointed out by previous writers, and its pres-

ence in the colder months at the northern part of its known range

has been taken to indicate that it is not migratory, at least in so

clear a manner as is the bottle-nosed whale (Hyperoödon ampulla-

tum). The fact that so large a proportion of the stranded speci-

mens has been taken on the coasts of islands is indicative of the

pelagie habitat of this species as contrasted with certain of the

porpoises that often frequent the shallower waters along the coasts.

368 THE AMERICAN NATURALIST [Vor. XL

LITERATURE

Acassız, L.

'68. [Mesoplodon from Nantucket, Mass.] Proc. Boston Soc. Nat.

Hist., vol. 11, p. 318

ALLEN, J. /

69. Catalogus of the Mammals. of Massachusetts: with a Critical

Revision of the Species. Bull. Mus. Comp. Zoöl., vol. 1, pp.

143-253.

ANDREWS, W.

'69. rid iris X6 diy (Mesoplodon sowerbiensis, Van Beneden).

s. Roy. Irish Acad. Dublin, vol. 24, sci., pp. 429-438, pl. 25.

Axe W

’70. Notice of the Capture of Ziphius sowerbyi. Proc. Roy. Irish

Acad. Dublin, ser. 2, vol. 1, sci., p. 49.

Aoust; C. W.

Osteologie unii äussere Erscheinung des Wals Sowerby's (Microp-

teron bidens (Sow.)). Bihang til Svensk. Vet.-Akad. Handl., vol.

11, pt. 1, no. 10, 40 pp., 2 pls.

BENEDEN, P. J. vA

’64. Sur un daapkan nouveau et un ziphioide rare. Mém. Cour. et

Autres Mém. Acad. Roy. Belge, Bruxelles, vol. 16, 21 pp., 2 pls., 5

gs.

BENEDEN, P. J. van

'66. Note sur un Maepida. sowerbiensis de la cóte de Norwége. Bull.

Acad. Roy. Belg, Bruxelles, ser. 2, vol. 22, pp. 218-221.

evenings P. J. va

Les siplioidos des mers d'Europe. Mém. Cour. et Autres Mém.

Acad. Roy. Belge, Bruxelles, vol. 41, 119 pp.

BrarNvILLE, H. D. DE.

'25. Note sur un cétacé échoué au Havre, et sur un ver trouvé dans

sa graisse. Nouv. Bull. Soc. Philom. Paris, 1825, pp. 139-141.

DESLONGCHAMPS, E

'66. Observations sur quelques dauphins appartenant à la section des

ziphiidés, ete. Bull. Soc. Linn. Normandie, Caen, vol. 10, pp.

168-180.

Do B. C.

. Mémoire sur le delphinorhynque microptére échoué à Ostende.

Roy. Belge, Bruxelles, vol. 12, 13 pp., 3 pls.

Fischer, B.

'92. Sur les caractères ostéologiques d'un Mesoplodon sowerbyensis

mile, échoué récemment sur le littoral de la France. Compt.

Rend. Acad. Sci. Paris, vol. 114, pp. 1283-1286.

No. 473] SOWERBY’S WHALE 369

FLower, W.

’72. On the Recent Ziphioid Whales, with a Description of the Skele-

ton of Berardius arnouxi. Trans. Zool. Soc. London, vol. 8, pt.

2 pp. 203-234, pls. 27-29.

FLoweEr, W.

mai y further Contribution to the Knowledge of the existing Ziphioid

Whales. Genus Mesoplodon. Trans. Zool. Soc. London, vol.

10, pt. 9, pp. 415-437, pls. 71-73.

Gray, J.

'66. Catalogue of Seals and Whales in the British Museum. London,

2d ed., vii + 402 pp., 101 figs.

GRIEG, J. A.

'98. Mesoplodon bidens, Sow. Bergens Mus. Aarbog, 1897, no. 5, 31

pp-, 2 pls., 6 figs.

GRIEG, J. A.

"98. Spidshvalen. Naturen, vol. 22, pp. 65-69, fig. 15.

GRIEG, J. A.

:04. Bidrag til Kjendskaben om Mesoplodon bidens, Sow. Bergens

e . Aarbog, 1904, pt. 1, no. 3, 39 pp., 14 figs.

GRIEG, J.

: 05. CUBES Naturen, vol. 29, pp. 110-115, 3 figs.

HYATT

'99. "Proceedings of the Annual Meeting, May 3, 1899. Report of the

Curator, Alpheus Hyatt. Proc. Boston Soc. Nat. Hist., vol. 29,

pp. 1-14 (see p. 9).

Mau, A. H.

'81. Om Micropteron bidens (Sow.) Malm, 3, Smadógling, funna nara

Marstrand den 30. Oktober, 1881. Göteborgs maturh. Mus.

Arsskr., vol. 3, pp. 32-36.

Mau, A. H.

'85. Om Sowerby’s Hval. Öfvers. Kongl. Svenska Vet.-Akad. För-

ndl., Stockholm, vol. 42, no. 5, pp- 121-153, pl. 9

Mam, A. W.

"1. Hvaldjur i Sveriges Museer. Kongl. Svenska Vet.-Akad. Handl.,

Stockholm, 1870, vol. 9, pt. 1, no. 2, 104 pp., 6 pls.

Rech, O.

:05. Ueber Form und Funktion der Halswirbelsäule der Wale. Jen.

Zeitschr. f. Naturw., new ser., vol. 33, pp. 149-252, 31 figs.

REINHARDT, J.

’80-'81. M esoplodon bidens, en Tilvext til den danske Havfauna.

Overs. Kongl. Danske Vidensk. Selskab. Forhandl., Kjobenhavn,

1880, pp. 63-72, pl. 2.

Rornscnuiup, W.

’93. Note on en bidens. Ann. Mag. Nat. Hist., ser. 6, vol.

370 THE AMERICAN NATURALIST | [Vor. XL

SOUTHWELL, T., AND CLARKE, W. E.

':86. On the Occurrence of Sowerby's Whale (Mesoplodon bidens) on

the Yorkshire Coast. Ann. Mag. Nat. Hist., ser. 5, vol. 17, pp.

53-59. .

SOUTHWELL, T., AND HARMER, S. F.

'93. Notes on a Specimen of Sowerby’s Whale (Mesoplodon bidens),

stranded on the Norfolk Coast. Ann. Mag. Nat. Hist., ser. 6,

vol. 11, pp. 275-284, pl. 15.

SOWERBY,

'04. Physeter bidens. Two-toothed Cachalot. British Miscellany,

no. 1, pp. 1-2, pl. 1.

Trog, F. W.

’85. A Note upon the Hyperoödon semijunctus of Pus Proc. U: S.

Nat. Mus., vol. 8, pp. 585-5806.

TURNER, W.

72. On the Occurrence of Ziphius cavirostris in the Shetland Seas,

and a Comparison of its Skull with that of Sowerby's Whale

(Mesoplodon seid Trans. Roy. Soc. Edinburgh, vol. 26, pp.

759-780, pls. 29-30

TURNER, W.

. '82. On a Specimen of Sowerby's Whale (Mesoplodon bidens) cap-

tured in Shetland. Proc. Roy. Soc. Edinburgh, vol. 11, pp. 443-

TURNER, W.

’82a. A kain of Sowerby’s Whale (Mesoplodon bidens) captured

in Shetland. Journ. of Anat. and Phys., vol. 16, pp. 458-470.

TURNER, W.

’85. The Anatomy of a Second Specimen of Sowerby’s Whale (Meso-

lodon bidens) from Shetland. Journ. of Anat. and Phys., vol.

20, pp. 144-188.

Turner, W.

’89. On the Occurrence of Sowerby’s Whale (Micropteron bidens) in

- the Firth of Forth. Proc. Roy. Physic. Soc. Edinburgh, vol. 10,

pp. 5-13, 1 fig.

FRESH-WATER RHIZOPODS OF NANTUCKET

JOSEPH A. CUSHMAN

Dvnrsa the spring of 1905 collections were made from the bodies

of fresh water on the island of Nantucket, Mass., by several mem-

bers of the Nantucket Maria Mitchell Association. This material

was turned over to me for examination. A portion of it was made

up of the sediment squeezed from submerged sphagnum. This,

as was to be expected, seemed to be the richest in Rhizopods and

contained many more species and individuals than the material

from the bottom of the larger ponds. Certain species seem to be

very limited in their distribution on the island, often occurring in

but one of the collections out of the fifty or more examined. In

such cases, however, there was usually an abundance of specimens

of the species in that one collection. Other forms which were to

be expected here were not met with at all. Of these Hyalosphenia

was the most striking genus, as it usually occurs in just such

material. Nearly all of the species found were of .small size

for their respective species and may be compared with the speci-

mens noted by the writer and Mr. Henderson from the alpine

region of the White Mountains (Amer. Nat., vol. 39, March,

1905, p. 155). The cause of this minimum size in the case of the

Nantucket specimens is hard to explain unless for some reason

there is not sufficient nourishment for them, but this does not

seem to be a reasonable explanation since the ponds are well sup-

plied with minute alge, especially desmids and diatoms. For

certain of the records I am indebted to Mr. W. P. Henderson.

The following species were found: —

1. Arcella vulgaris Ehrenberg. Breadth 52-55 s; height 21-

23 n; aperture 12-14 y.

Common. Hummock and Gibb's Ponds and from bog moss.

2. Arcella discoides Ehrenberg. Breadth 46-75 »; height 20-

25 n; aperture 8-19 y.

Common, but of small size. Hummock and Sesacha Ponds and

from sphagnum in different parts of the island.

3. Centropyxis aculeata Stein. Breadth 65-72 x; height

30-38 u; aperture 11.5-18 y.

371

372 THE AMERICAN NATURALIST [Vor. XL

Of small size. Common in Hummock Pond and in sphagnum

swamps.

4. Centropyxis aculeata ecornis Ehrenberg. Length 94 u;'

breadth 78; aperture 26. From sphagnum.

5. Quadrula symmetrica Schul. Length 68 x; breadth 38 u;

aperture 13.5 y.

This species occurred but once and then in considerable num-

bers. It was from bog moss material near the town. The speci-

mens were very uniform in size and were small.

6. Difflugia globosa Dujardin. Diameter 58-65 yp. Hum-

mock Pond.

7. Difflugia pyriformis Perty. Length 90-102 x; breadth

45-54 u; aperture 21-24 y.

Small. Common in Gibb’s and Wigwam Ponds and in sphag-

num.

8. Difflugia acuminata Ehrenberg. Length 125-168 x; breadth

40-71 »; aperture 12-27 y.

Of small size. Wigwam Pond and from bog moss.

9. Difflugia corona Wallich. The only specimens referable to

this species were from Wigwam Pond. These were of the usual

shape but somewhat undersized and their shells instead of being

composed of sand grains were almost entirely made up of diatom

frustules. Diameter 112-132 »; aperture 50 p.

10. Difflugia constricta Ehrenberg. Length 60-87 »; breadth

36-46 u; aperture 18 4. Specimens of this species were found in

but one lot of material and in this they were common. They

were from bog moss near the town. The specimens were all

undersized.

11. Difflugia lobostoma Leidy. Length 845; breadth 52 p;

aperture 13 x. From sphagnum.

12. Lecquereusia spiralis Ehrenberg. Length 94 »; breadth

68 p; thickness 58 y.

This species was found in material from the north head of Hum-

mock Pond only. The shells were composed of the peculiar pel-

lets characteristic of this species. The specimens were small for

the species.

13. Euglypha alveolata Dujardin. Length 90 »; breadth 75 #5;

aperture 23 p.

"This species was met with but once, viz., in material from Wig-

No. 473] NANTUCKET RHIZOPODS 373

wam Pond. The specimens of this species differ from those of

most of the others in being of at least medium size for the species.

14. Euglypha ciliata Ehrenberg. Length 44-65 p; breadth,

minimum 20-24 u; maximum 25-40 u; aperture, maximum 14.5 u,

minimum 10 y.

This species may be called common. It was found in material

from Hummock Pond and in various collections from bog moss.

Unlike the preceding species of this genus the specimens as a

rule were undersized.

15. Assulina seminulum Ehrenberg. Length 48 x; breadth

38 u; thickness 17 p.

Specimens of this species were found in material from the south

end of Hummock Pond. They were of small size.

16. Heleopera sphagni Leidy. Length 145 a; breadth, max-

imum 100 x, minimum 48 y

This species was found only once but in that material it was

common. It was from sphagnum near the north end of Hum-

mock Pond. In size the specimens as a rule were above the

average for the species, but were comparatively thin.

17. Heleopera petricola Leidy. Length 102; breadth 60 x;

aperture 394. From sphagnum.

18. Nebela collaris Ehrenberg. Length 81-150 x; breadth

i s; aperture 16-23 v. From sphagnum.

. Nebela caudata Leidy. A single specimen of this rare

species was obtained from sphagnum.

20. Cyphoderia ampulla Ehrenberg. Length 110-112 y;

breadth 38-46 p; aperture 10-12 y.

In a collection from bog moss near the town this species was

abundant, but was not met with elsewhere on the island. ‘The

specimens were of very uniform size and small for the species.

21. Trinema enchelys Ehrenberg. Length 29-70; breadth

12-34 u; aperture 4-13 u. From sph

22. Acanthocystis spinifera Greef. Diameter with spines 75 x.

Specimens which seemed to be this species were found in

material from Reedy Pond. They closely approximate the fig-

ures of a species of this genus figured by Leidy without a specific

name. `

Boston Socrety or NATURAL History

NOTES AND LITERATURE

ZOÖLOGY

Weismann’s Theory of Descent.'— “When a life of pleasant labor

is drawing towards a close the wish naturally asserts itself to gather

together the main results, and to combine them in a well-defined and

harmonious picture which may be left as a legacy to succeeding gen-

erations.” Thus does the genial author set forth the aim and motive

of his book. And no biologist can fail to be grateful for the publica-

tion of these charmingly readable lectures, presenting in two ample

volumes the best thoughts of a clear and vigorous thinker. The

translation into English has been admirably done.

The early chapters set forth once again the data of evolution and

the most striking examples of adaptation, for many of which, in the

reviewer's opinion, no other explanation so satisfactory as that of

natural selection has ever been offered, and which consequently justify

the further elaboration of the theory to which the book is devoted.

Four more chapters present the facts of germ cells and fertilization

and then the germ-plasm theory is elucidated; criticisms directed

against it are answered; various accessory theories, particularly that

of intragerminal selection are set forth; and finally its relation to the

formation of species is fully discussed.

It is impossible in the space of a brief review to set forth Weismann's

standpoint; it is unnecessary, also, for it is already well known to most

naturalists. A few words may, notwithstanding, be devoted to his

most recent accessory hypothesis upon which he lays the greatest

possible stress, that of Germinal Selection. In attempting to explain

the gradual disappearance of organs he first hit upon the hypothesis -

of panmixia but, however satisfactory as a factor of incipient deteriora-

tion, it became clear that panmixia could not account for complete

elimination. The necessary hypothesis was found in a struggle

among the organ-determining germinal particles — the determinants

— due to the limitations of nutrition supplied to the germ cells. "The

‘Weismann, A. The Evolution Theory. Translated with the author's co-

Speration by J. A. & Margaret R. Thomson. London, E. Arnold, 1904. 8vo,

2 vols., xvi -- 416 and 405 pp

375

376 THE AMERICAN NATURALIST [Vor XL

weaker determinants get less food, grow less well, and consequently

become in turn still less capable of nutrition. Once started on the

downward path the determinant descends more and more until it is

wholly eliminated. Nothing can save the determinant from this fate

except the elimination by natural selection of the adults of the strain

possessing the deteriorating determinant — and this will only happen

when the degenerating organ again becomes necessary to the welfare

of the postembryonic organism.

Not only the degeneration but also the upbuilding of an organ can

be explained by the hypothesis of germinal selection. For a certain

strong determinant once having been selected, it will gather to itself

all available nutrition at the expense of the other determinants; it

will flourish in the race and will only stop its continual accretions

when it produces organs so developed as to be disadvantageous to the

active organism.

In eritieising this hypothesis one can only admit that it explains so

many facts that we hope it will some day be demonstrated. As it is,

it stands to-day a bald hypothesis based on numerous probable but

unproven assumptions.

Coming now to Weismann’s position on the origin of the specific

type we find it of interest as being clearly opposed to that of de Vries.

Both theories accept the idea of unit characteristics which are repre-

ous in the germ by particles. The theories begin to diverge in

t to these particles. De Vries concludes that these particles

die suddenly, probably by molecular changes within them, so that

a new characteristic arises suddenly and tends thereafter to persist.

The characteristic may be modified by selection, but its essential

nature cannot be changed thereby. Weismann on the contrary

regards these particles as being in a constant state of variation which,

when continued long in one direction, will result in the elimination

of a character or in its excessive development. Species are originally

connected by transition forms as are to-day the terrestrial snails of the

Celebes (page 299). Weismann repeatedly emphasizes the idea that

all variations are quantitative and that “what appears to us a quali-

tative variation is, in reality, nothing more than a greater or less"

(vol.2, p. 151). Here then we have clearly set forth the issue between

de Vries and Weismann: one maintains that variations of phylo-

genetic significance are always qualitative; the other, that they are

quantitative only. This difference between the two schools would

seem to be a qualitative one. But alas for the peace of mind of him

who seeks clear distinctions, the quantitative may produce the qualita-

No. 473] NOTES AND LITERATURE 377

tive, as Weismann points out (vol. 2, p. 152)! He says, a cell changes

its constitution (1. e. undergoes a qualitative change) when “the pro-

portion of the component part and chemical combinations” is dis-

turbed, “when, for instance, the red pigment-granules which were

formerly present but scarcely visible increase so that the cell looks red.

If there had been no red granules present, they might have arisen

through the breaking up of certain other particles — of protoplasm,

for instance, in the course of metabolism, so that, among other sub-

stances, red granules of uric acid or some other red stuff were pro-

In this case also the qualitative change would depend on an

increase or decrease of certain wap ond molecules and atoms consti-

tuting the protoplasm molecule." The foregoing quotation sets forth

clearly Weismann's conception of the way in which a wholly new

character may arise and I imagine that de Vries would accept the

hypothesis. They would differ only as to whether there was at first a

great chemical change or a slight one increasing with successive gen-

erations. Thus the essential difference between de Vries and Weis-

mann shows itself to be one of degree only.

C. B. D.

The Oyster. — A very fascinating book presenting in a thoroughly

scientific, yet in a readable and popular style the complete develop-

ment and anatomy of the oyster, the possibilities of oyster culture,

the cause of the decline in our oyster industry, and the remedy.

One can hardly realize that since statistics have been kept (1865),

there have been taken from the Chesapeake Bay, upwards of four

hundred million bushels of oysters. “This ineonceivably vast amount

of delicate, nutritious food has been yielded by our waters without

any aid from man. It is a harvest that no man has sown; a gift

from bounteous nature."

"This great productiveness shows how favorable this body of water

is for the oyster, and what might be done under judicial management

and culture. It is doubtful if the present areas of oyster beds (about

two hundred square miles) can ever regain their former prestige even

if they could be utilized to the best advantage by culture. The de-

mand has continued and will continue to outgrow the supply. The

area occupied by the natural beds, however, covers but a small por-

‘Brooks, William K. The Oyster. A Popular Summary oj a Scientific Study.

Second and revised edition, with introductions by Daniel C. Gilman and Ira

Ramsen. Baltimore, Johns Hopkins Press, 1905. 12mo, 225 pp., illus.

378 THE AMERICAN NATURALIST [Vor. XL

tion of the bottom suitable for oyster-farming, “and it is safe to esti-

mate the total area of valuable oyster-ground in our state at one thou-

sand square miles.” If this vast area could be properly developed,

there should be a good supply for years to come. The author points

out clearly what should be done, and we trust he will have the coöpera-

tion of every intelligent man in saving and redeeming this great in-

dustry.

C.W.J

Sea-shore Life.! — Dr. Mayer has presented to the public a popular

work which, while not without merit, shows a carelessness in arrange-

ment and constant misstatement of facts which we hardly expect in

these days when accuracy and precision of classification are considered

of paramount importance.

'The book presents a truly attractive appearance, and the figures

with few exceptions are new and really valuable. The closing table

of references seems well chosen.

The text, however, is the part which gives most evident signs of

hasty "uunc: The sections dealing with “Jellyfishes and Hy- .

droids" and with a Anemones and Corals" reveal no startling

peculiarities, nor, except for rather unimportant details, do the foe

lowing sections until we arrive at that entitled “ The Crustaceans.”

Here the arrangement is startling indeed. Under the subheading

“The Barnacles," the following genera are discussed and figured:

Balanus, Coronula, Lepas, Homarus, Palinurus, and Alpheus.

“The Crayfishes” follow in a perfectly rational manner. Next

come “Shrimps and Prawns.” On page 89 we read: “Shrimps are

known to science as the Schizopoda!” And now these following

genera, presumably Schizopods are discussed Crangon, Paleemon-

etes, Penzus, Stenopus, and last but by no means the least in this

connection, Mysis. Among the “Hermit Crabs” we find Hippa

and Squilla. On page 107, Geocarcinus occurs among the “ Fid-

dler Crabs,” and under this same main heading the spider crabs and

Limulus. Among the molluscs under the heading “The Fresh-water

Mussels,” we find Pecten, Anomia, and Meleagrina.

e must not, however, presume to be hypercritical. For all its

peculiarities this book will probably amuse as many as it leads away

from the devious paths of correct scientific classification.

T. B

‘Mayer, A. G. Sea-shore Life. The Invertebrates of the New York Coast.

New York Aquarium Series, No. 1. Published by the New York Zoólogical

Society, 1905. 8vo, 181 pp., 119 figs.

No. 473] NOTES AND LITERATURE 379

Alder and Hancock’s British Tunicata.'— At last, thirty-eight

years after the death of one of the authors (Alder), and thirty-two

years after the death of the other, this work on British Ascidians, long

known by students of the group to be hidden away somewhere in

manuscript, has emerged to the light of day in a well printed volume

of 146 pages and 20 plates, dressed in the familiar costume of the Ray

Society’s publications.

The historical statement by Canon Norman, a personal friend, if

I mistake not, of both authors, gives briefly the vicissitudes through

which the work has passed both before and since the authors laid it

aside for the last time. There is something rather melancholy in a

story like this. Pity it is, first having regard for these worthy natur-

alists themselves, that the fruits of their labors might not have long

ago reached the hands of other students of these animals. Thus

would a field of knowledge have been enriched, and deserving men

could have received the recompense of acknowledgment richly their

due, which by this delay has been largely denied them. And the

somberness of the picture will be increased a little for many natur-

alists by the query, with some undoubtedly made more real by per-

sonal experiences, as to how far works of their own hands may have

a similar fate in store for them.

One of the serious difficulties that has always been encountered by.

proposals to publish this monograph, Mr. Norman tells, has been the

illustrations. A great number of these was left particularly by Mr.

Hancock. Of these many were in various stages of elaboration, so

that the two-fold problem of what to do with unfinished drawings,

and of providing funds for reproducing the large number that was

finished had to be met. But little use has been made, we are given

to understand, of the unfinished figures. Even so, about 140 are

published in the plates, 75 of which are colored; and there are 23 text

figures. There can be little doubt that the illustrations will consti-

tute one of the chief values of the work. Most of them are admirably

drawn, and the reproduction is in the main good. The habitus fig-

ures should be specially useful as a seaside aid to identifying the species.

A historical sketch of the knowledge of the group introduces the

work proper. ‘This would have been of high value had it been pub-

lished long ago; but with the recent extensive studies on the: liter-

ature by Herdman and Seeleger, this portion of the monograph is

made to a considerable extent antiquated.

' Alder, J., and Hancock, A. The British Tunicates. Vol. I. London,

published by the Ray Society, 1905. 8vo, 146 pp., 20 pls.

380 THE AMERICAN NATURALIST [Vor. XL

Hancock’s well known paper “On the Anatomy and Physiology

of the Tunicata,” originally published in the Journal of the Linnean

Society, 1867, is appropriately reprinted here.

Naturally and very wisely, Mr. Hopkinson has refrained from any

revisions of the text beyond what was absolutely necessary to rectify

obvious typographic errors. It results from this that in several partic-

ulars both as to interpretation of structure, and classification, there is

want of conformity to views now held. The most striking thing in

this regard is the contention for the molluscan affinities of the tuni-

cates. (The only discussion, however, of this question is that con-

tained in Mr. Hancock’s memoir above referred to.) The arguments

put forward in support of this view are decidedly interesting reading

from a historical point of view, and from the standpoint of now

approved criteria of homology. It is surprising that Hancock

should have failed even so much as to mention the theory of the

vertebrate relationships of the group. One must suppose that at

the time of writing this memoir the author had not yet become

acquainted with Kowalevsky’s important paper on embryology,

published the year before. The only clue given us as to what either

author’s later views were on this fundamental matter, is found in the

reference to a paper by Hancock, published in 1870, “On the Larval

State of Molgula” ete. Here the author concluded that since there

are two distinct modes of development in closely allied genera of the

Tunicata, the tadpole condition is non-essential; and he expressed

the belief that this fact would influence the theory of the vertebrate

relationship of the group.

is volume treats only of the genus Ascidia, in the systematic

pert, as the genus was then understood. Thirty species are regarded

as "good," and five varieties are recognized.

Although the volume is numbered one, I see no indication that

another is to follow.

It is certainly well that this work is now published, but as certainly

it would have been much better could it have been done long years ago.

W. E. R.

Schillings's With Flash-light and Rifle.'— The rapidity with which

the larger mammals of Africa are becoming exterminated makes it

!Schillings, C. G. With Flash-light and Rifle. Photographing by Flash-

light at Night the Wild Animal World of Equatorial Africa. "Translated and

abridged by n Zick, Ph. D. New York, Harper Brothers, 1905. 8vo,

xiii + 421 pp., illus

No. 473] NOTES AND LITERATURE 381

imperative that no time be lost in procuring specimens for study and

in investigating their habits. Schillings, a German hunter-naturalist,

is one of several explorers who in recent years have made expeditions

into the Dark Continent and have brought back valuable collections

of its rich fauna.

Four expeditions were made into German East Africa by Schillings,

and a large number of carefully prepared specimens of the more im-

portant game mammals were secured and brought to Berlin for the

imperial museum. Several new species have been described from

this material (mainly by Matschie) and many others have been forms

that are very rare in collections. ‘The present work is mainly an ac-

count of the experiences of Herr Schillings during these four journeys

into the African wilderness, and is translated and abridged by Henry

Zick from the original Mit Blitzlicht und Büchse (1905).

The chief feature of the book is the large number of photographs

of these animals in their natural surroundings, taken by the author

during his three last expeditions. Many of these pictures are remark-

able and extremely valuable, taken at night by flashlight as the ani-

mals came to the water-holes to drink. "Other views were obtained

by means of a telephoto lens and illustrate a number of the antelopes

and other day-feeding species. Those of the giraffe, the zebra, the

lion, and the leopard are particularly noteworthy. Many of the pho-

tographs, however, are altogether too indistinct to be of any value,

though from an impressionist’s standpoint they may pass as pictures.

These less satisfactory views have been largely omitted from the

English edition, however.

While the photographs are the main feature of the book and by

themselves are of permanent value, the narrative is also of interest

as a popular treatise on the habits of the species dealt with. A num-

ber of notes on the larger mammals are recorded in the course of the

narrative, such as the blending of the black and white striped zebras

with “the colors of the steppe, so that they are hard to distinguish even

at close range” and “ under certain lights they appear grayish.” That

lions at certain times of the year may be found in “troops” of as many

as seventeen the author has had personal proof. It is also true that

the lynxes of our own country may at times be found in packs although

a recent nature writer has dogmatically denied this. The versatility

of the long-necked Waller gazelle is shown in its habit of standing on

its hind legs, after the manner of goats, in order to increase the vertical

extent of its feedingrange. Inaddition to chapters on the rhinoceroses,

the elephant, the lion, the giraffe, the zebra, antelopes, and the smaller

382 THE AMERICAN NATURALIST [Vor. XL

carnivores, the latter part of the book deals particularly with the in-

habitants of the country and the difficulties that confront the explorer.

The translation is in the main good, though marred here and there

by a grammatical error and by a certain looseness of expression, as

where scorpions are termed "reptiles," and hippopotami are famil-

iarly spoken of as “river hogs”; the use of capitals for the authority

of Latin names seems also to have afforded a stumbling block. An

index might have added to the usefulness of the book.

G: M A.

Notes.— Recent Extension of the Range of the Green Crab. About

the year 1892 or 1893, I first began to notice at Cohasset, Mass., an

occasional specimen of a green crab. These crabs were about two

inches in diameter and were seen at low tide on the mud flats about

our float in company with Cancer irrorata. From that time on I

noticed a gradual increase in their numbers but thought nothing of

it until 1902, when a reference to a “green crab" in a physiology lec-

ture made me wonder if the crab which had recently become so abun-

dant at Cohasset was the same as that experimented upon. On

submitting specimens to Dr. Walter Faxon for determination, I learned

that they were Carcinides manas, a species that was not believed to

occur north of Cape Cod. In the course of the summer I collected

specimens at the following additional localities: Nahant, Lynn, and

Ipswich, Mass., and Kittery, Maine. In the same year (1902) it was

collected at Manomet Point, Mass., by Mr. J. A. Cushman, and a

record of its occurrence at Portland, Maine, was obtained by Dr.

Faxon. Miss Mary J. Rathbun in her * List of New England Crus-

tacea," gives the following additional localities in Maine: Harpswell;

New Meadows River, near Harpswell; and. Eagle Harbor, Casco

Bay; all, I believe, based on records obtained shortly previous to 1904.

The next spring, 1904, I determined to find out just how far to the

eastward the green crab had reached, but gave up the undertaking

after several attempts to procure specimens from Cohasset had proved

unsuccessful and after hearing from Kittery that there were practi-

cally none to be found there. The winter of 1903-04 had been unusu-

ally severe along the shore and the ice consequently very thick. It

had scraped every bit of eel grass from off the mud flat at the edge of

which the year before I had been able to find an abundance of green

crabs and it had probably killed off the crabs along with the eel grass.

During the summer I made careful search for more specimens of

Carcinides at every locality where I collected and especially at Cohas-

No. 473] ‘NOTES AND LITERATURE 383

set, but did not find so much as a dead carapace. Mr. Cushman,

however, after considerable hunting, managed to secure a few living

specimens at Manomet Point. Farther north they seem to have been

for the time exterminated.

It is unfortunate that accurate dates cannot be given for the first

appearance of this crab at the various stations where it has been taken

north of Cape Cod. All the data I can offer on this point are: (1)

my impression that they first appeared at Cohasset about 1893; (2)

the statement of Mr. Stephen Decatur that he began to notice them at

Kittery, Maine, at about the same time; (3) the negative evidence

that the species is not included in Professor Kingsley’s “Invertebrata

of Casco Bay” published in 1901; and (4) the fact that my uncle, Dr.

W. S. Bryant, who did considerable collecting and dredging at Cohas-

set about twenty years ago, had never seen them there.

From these data it appears that the extension of the green crab’s

range from Cape Cod to at least as far north as Kittery, Maine, oc- .

curred very rapidly; that it worked its way slowly along the shore

from the neighborhood of Kittery; and that it is not yet permanently

established north of Cape Cod.

At Cohasset this last summer, 1905, I found a few dead immature

specimens washed up, and on November 19, 1905, Mr. T. Barbour

and I collected several living specimens, some nearly full grown, in

tide pools on one of the other reefs. There is hope, therefore, that

it may again, after a few favorable seasons, become common north

of Cape Cod.

The green crab is found in tide pools, along the edge of mud flats,

on beaches, and under overhanging rockweed. It does not seem to-

burrow in sand or mud as does Cancer, when it is left by the tide. It

is therefore easily detected and its presence or absence should be noted

by everyone who has the opportunity to observe the fauna of our north-

ern New England coast.

Owen BRYANT

The Pelvie Region of the Porpoise. Because of the degeneration

of the pelvie girdle in the porpoises and other cetaceans, it has

been impossible on purely osteological grounds to state with pre-

cision which vertebr® in these animals correspond to the sacral ver-

tebre of other mammals. Knauft (Jen. Zeitschr. f. Naturw., vol. 40,

pp. 253-318) has attacked this problem from the standpoint of the

spinal nerves and has shown that the vertebral column is so related

to the lumbo-sacral plexus in the porpoise that instead of possessing

14 lumbar vertebra as has been generally assumed, this animal has.

384 THE AMERICAN NATURALIST [Vor. XL

only 6 and that consequently its sacral vertebrae are much more ante-

rior in position than has heretofore been supposed.

G. H. P.

Adaptations in the Arteries of the Horse. Barner (Jen. Zeitschr. j.

Naturw., vol. 40, pp. 319-382) in a study of the thoracie and abdom-

inal Ser of the horse has shown that the structure of the arteries

varies with the blood pressure, the mechanical relations to the sur-

roundings, and the functional relations of the vessels. As the blood

pressure decreases in the more distant vessels the arterial walls become

thinner and take on more the character of muscular tubes. Where

arteries receive support from surrounding parts, as for instance where

the aorta pierces the diaphragm, their walls are thin. Finally adap-

tations are to be seen where special conditions exist; thus the vertebral

artery has its elastic elements unusually developed in relation to a

- demand for the utmost freedom of movement in the horse's neck.

Two New: Chipmunks. Dr. C. H. Merriam (Proc. Biol. Soc.

Wash., June, 1905) describes two new chipmunks of unusual

interest. One of them, called Eutamias amenus operarius, is the

common little four-striped species of the Boreal zone in Colorado.

It has been referred to Say's E. quadrivittatus, but that species lives

in the foothills, and the mountain form is actually nearest to E. amamus

of the Californian Sierras. In view of the widely severed habitats of

the forms operarius and amenus, and the absence of any evidence of

intergradation, it would seem that the Colorado animal should rather

rank as a full species, Eutamias operarius. The other new chipmunk

is E. hopiensis, an unusually handsome form from the Painted Desert,

Arizona. DD ta C:

The Ant Genus Liometopum. Dr. W. M. Wheeler (Bull. Amer.

Mus. Nat. Hist., Nov., 1905), gives an interesting revision of the genus

Liometopum, as found in North America, with a discussion of the

habits of the species. The geographical distribution of Liometopum

is of especial interest, as it is one of those types which may be desig-

nated paleoboreal; that is to say, it appears to have had a*boreal

distribution in times past, but has now been driven south, where it

persists, with few representatives, in the southern parts of the temper-

ate zones of both hemispheres. Herein it reminds one somewhat of

the butterfly genus Parnassius, but it differs from that in the smaller

No. 473] NOTES AND LITERATURE 385

number of species, and the much. less alpine habitat. The species

are three, so far as known: L. microcephalum of southern Europe,

L. lindgreeni of Assam and Burma, and L. apieulatum (with varieties

or subspecies occidentale and luetuosum) of western North America.

In New Mexico L. apiculatum ascends to about 8000 ft., and in Mex-

ico even somewhat higher. GBA C.

Ichthyological Notes.— In the Memoirs of the New South Wales

Naturalists’ Club, (no. 2, 1904), Mr. Edgar R. Waite gives a

most useful catalogue of the fishes of that State, with reference to the

descriptions of each species. Mr. Waite has adopted a modern

sequence in his classification and the names adopted by him show

a praiseworthy attention to the necessary rules of nomenclature.

Five hundred and twenty-six species are enumerated, most of them

occurring in the harbor of Sydney.

In the Records of the Australian Museum, 1904, vol. 5, Mr. Waite

has a useful review of the gobies with separate ventrals, known as

Eleotrids, found in the waters of New South Wales. In another

paper in the same Records, Mr. Waite discusses the breeding habits

of the Fighting Fish, Belta pugnax.

In the Transactions of the New Zealand Institute, Professor W. B.

Benham of Otago University describes a new species of the great

pelagic Oar-fish, under the name of Regalecus parkeri.

In the Meddelelser fra Kommissionen jor Havundersögelser, of Den-

mark (vol. 2, no. 7, 1905), Dr. Adolph Severin Jensen gives a mono-

graphie account of the ear-stones of fishes dredged in the “Polar

Deep." He develops the fact, hitherto unknown, that otoliths in

great quantities are deposited in the northern seas at the present

time. Many of these belong to the small codfish, Micromesistius

poutassou, a fish not properly reckoned as arctic.

In the Bulletin of the Bureau of Fisheries jor 1904 (vol. 24) Mr.

Frederick A. Lucas discusses the osteology of the Tile-fish, Lopho-

latilus chameleonticeps, a singular fish of the depths of the Atlantic.

He finds the family Latilide, to which it belongs, well defined, and

well separated from Malacanthus and from Bathymaster, which

have been wrongly associated with it. In the same Bulletin, Mr. C.

E. Silvester discusses the blood-vascular system of the Tile-fish.

In an elaborate paper in the Proceedings of the Washington Aca-

demy of Sciences, William F. Allen, of Stanford University, describes

386 THE AMERICAN NATURALIST [Vor. XL

in great detail the circulatory system in the fishes with mailed cheeks,

or Loricati. Among other things he shows that the Ophiodontidze

and the Zaniolepide, should be separated, as dis inct families, from

the Hexagrammidee.

In the Memoirs of the New York Academy oj Science, (vol. 2, 1905),

William E. Kellicott gives an elaborate and useful account of the

development of the vascular and respiratory systems of the dipneu-

stan genus, Neoceratodus. He calls this genus by the same name

as its extinct ancestor or predecessor, Ceratodus.

In the Bulletin of the Illinois State Laboratory of Natural History,

Dr. S. A. Forbes and R. E. Richardson describe a new Shovel-nosed

Sturgeon from Illinois River, under the name of Parascaphirhynchus

albus. This species is found mixed with the ordinary Shovel-nose,

Scaphirhynchus platorhynchus in the proportion of about one to five

hundred. The new genus has the belly and breast naked, the ribs

twenty or twenty-one. In Scaphirhynchus, the belly is mailed, the

ribs ten or eleven only. i -

In the Bulletin of the United States Bureau of Fisheries for 1904,

Mr. Chancey Juday, of the University of Colorado, records the spe-

cies of fishes in Boulder Creek, twenty-five i in number, one of them, `

iscus evermanni, being new to science.

In the same Bulletin (vol. 24, 1904) Professor Kakichi Mitsukuri

of the Imperial University of Tokyo, discusses the domestication or

breeding of various fishes, turtles, clams, etc., in Japan. His account

of the aberrant forms of the gold-fish, RER auratus, is especially

interesting. About thirty monstrous forms are figured.

In the same Bulletin (vol. 24, 1904) Dr. D. S. Jordan and Surgeon

J. C. Thompson give an account of the fishes taken by the latter while

stationed at the Tortugas in Florida. Two hundred and eighteen

species are enumerated, several of them not previously taken in the

waters of the United States. New species are: Holocentrus tortuge,

Eviota personata, Gnathypops aurifrons, and Execestides egregius, the

latter a new genus of Uranoscopide. A new genus, Etelides is based

on the fish called Anthias aquilionaris. It differs from Etelis in the

naked jaws, and the union of the two dorsal fins.

In a volume on The Bahama Islands, by Dr. George B. Shattuck

(Baltimore, 1905), Mr. Barton A. Bean contributes an annotated

list of the fishes known, with a number of excellent colored plates,

the work of Mr. A. H Baldwin. ; i

No. 473] NOTES AND LITERATURE 387

In the Report of the Commissioner of Fisheries for 1904, Professor

John O. Snyder, of Stanford University, discusses the distribution of

river fishes about San Francisco Bay. He shows also that Leuciscus

caurinus of Richardson is a true Leuciscus, and a species distinct

from M ylocheilus lateralis, hitherto supposed to be the same. Ptycho-

cheilus grandis of the Sacramento is also, as Agassiz supposed, dis-

tinet from P. oregonensis, of the Columbia.

Mr. T. Kitahara (Annot. Zoöl. Jap., jor 1904) of the Japanese

Bureau of Fisheries corrects the nomenclature of some of the trout |

and salmon of Japan, as given by Jordan and Snyder in 1902. He

shows that the “Ito” should stand as Hucho perryi, and the

““Masu,” as Salmo masou. The “Iwana,” Salvelinus pluvius, he

regards as identical with Salvelinus malma.

Jordan (in the same Annotationes, and in the Proc. U. S. Nat.

Mus., vol. 27) reviews Mr. Kitahara's paper, recognizing the following

species of Salmonide in Japan :—

Oncorhynchus nerka (Walbaum); Beni-masu.

Oncorhynchus milkschiteh (Walbaum); Gin-masu.

Oncorhynchus keta (Walbaum); Shake or Sake.

Oncorhynchus gorbuscha (Walbaum); Karafuto-masu.

Salmo masou (Brevoort); Masu, Ame-no-uwo, Yamabe.

Hucho perryi (Brevoort); Ito.

Salvelinus malma (Walbaum); Iwana, Ame-masu.

Salvelinus kundscha (Walbaum).

Plecoglossus altivelis (Schlegel); Ayu.

The king salmon, Oncorhynchus tschawytscha (Walbaum), has

been since recorded from the northern part of Hokkaido, in a letter

from Mr. Kitahara. Mr. Kitahara also notes the capture of Salmo

rivularis, the California Steelhead Trout, (wrongly called Salmo

gairdneri), off the northern part of the main island of Hondo. These

two species should be added to the Japanese list.

The most elaborate faunal monograph yet published by the Bureau

of Fisheries, and one of the most beautifully illustrated volumes in

existence is the report of Jordan and Evermann on the fishes of Hawaii,

published as part of the Bulletin of the United States Fish Commis-

sion for 1903, the last bulletin issued before the change of the name of

the Commission to that of the Bureau of Fisheries.

In this volume are described in full four hundred and thirty-nine

species of Hawaiian shore fishes, nearly all of which are admirably

figured. Especially noteworthy are the seventy-three colored plates

388 THE AMERICAN NATURALIST [Vor. XL.

taken from life in Honolulu and Hilo. Most of these are the work

of C. B. Hudson and A. H. Baldwin. Captain Hudson’s paintings,

made in oil, from living fishes in the aquarium, here perfectly repro-

duced, constitute beyond question, the finest series of fish portraits

ever made by any artist. The wonderfully rich fish fauna of the

Hawaiian Islands is now one of the best known in the world.

This fauna is frankly and entirely tropical and almost all the spe-

cies belong to genera found in the South Seas. The species are,

however, in large part different. Of the four hundred and thirty-

‘nine species recognized, two hundred and thirty-two are confined,

so far as known, to Hawaii; one hundred and forty-two are found

also in Samoa and Fiji; fifty-three are common to Hawaii and Japan,

and thirty-four to Hawaii and the offshores of Mexico. The singular

isolation of Hawaii, which, so far as fishes are concerned, has no paral-

lel among other tropical island groups, may be due in part to the

directions of the ocean currents. These currents seem to play a

large part in the transportation of species, by floating young fishes.

from place to place.

The collections on which this volume is based have been made by

the authors, by Oliver P. Jenkins, the first to collect on a large scale

in Hawaii, by Charles H. Gilbert, John O. Snyder, Walter K. Fisher,

Charles C. Nutting, Michitaro Sindo, and others.

Part 2, of the same Bulletin, issued as a separate volume, contains

an account of the fishes taken about Hawaii in the deep-sea work of

the Albatross. "This volume is by Dr. Charles H. Gilbert, who was

naturalist in charge on the Albatross in 1902.

About eighty species were obtained in the deep seas. Nearly all

of them are new, an addition to our knowledge of fishes with few par-

allels in the records of deep-sea dredging. Many new genera are

included, and a considerable number of the offshore genera of Japan

have their range extended to Hawaii. Among these are Pegasus,

Aracana, Gadomus, Hoplichthys, Melanobranchus, Lophiomus, Cal-

liurichthys, and Polymixia.

This volume is to be commended for the careful accuracy of the

descriptions and for the excellence of the plates.

The Philosophical Institute of Canterbury in New Zealand pub-

lishes an index to the New Zealand Fauna by Captain F. W. Hutton.

In this volume is a list of the species of fishes known — without syn-

onyms or references, the nomenclature being apparently carefully

considered.

No. 473] NOTES AND LITERATURE 389

In the Proceedings of the Academy of Natural Sciences at Phila-

delphia (1905) Henry W. Fowler publishes a number of papers on

rare or little known species of fishes in the museum of the Academy.

One of these treats of fishes of Borneo, with a number of new genera.

and species; another of Arctic fishes, from Port Barrow; another,

in connection with Dr. Benjamin Sharp, on the fishes of Nantucket.

Two others treat of rare or little known forms allied to the Mackerel.

A new subgenus, Sierra, is proposed for Scomberomorus cavalla;

another, Lepturacanthus, for Trichiurus savala. Caranz ruber be-

comes the type of Elaphrotoxon and Vexillicaranx is typified by

Caranx africanus. Rhapiolepis is based on Scomberoides tol. The

Pilot-fish of the Pacific, found in Hawaii and Japan is described

as Naucrates polysarcus, the type being from the West Coast of

Mexico. If the species is valid, some one of the older names, given

to Pacific specimens may belong to it.

In the Proceedings of the United States National Museum (vol. 28),

Dr. Theodore Gill has a number of short papers on new points in

ichthyology. Prionotus stearnsi, a smooth-headed gurnard from

Florida, is the type of a new genus, Colotrigla. The insertion of

the pectoral fins furnishes the chief distinctive peculiarity. Simopias

is a new name proposed as a substitute for Pelor, preoccupied, and

Rhinopias is proposed as the generic name for the singular Scorpena.

jrondosa of Martinique. The subfamily Pelorine becomes Inimi-

cine, for the genus Inimicus. Neosebastes entaxis, a Japanese fish,

is properly removed from Neosebastes to become the type of Sebas-

tosemus Gill.

In the Report of the United States Commissioner of Fisheries, Dr.

Gill gives an interesting historic review of the ichthyology of Massa-

chusetts. Attention is called especially to the number of waifs,

young fish from the tropics, found each year, where the Gulf Stream

reaches the coast of Massachusetts.

In the Proceedings of the United States National Museum (vol. 28,

1905), Messrs. Jordan and Seale discuss the collection of fishes brought

by Professor Bashford Dean from the island of Negros in the Philip-

pines. One hundred and eighteen species, mostly small fishes from

the coral reefs, were obtained, of which eighteen are new to science.

The fish fauna of the Philippines is essentially that of the East Indies,

with a dash of forms from the shores of Hindostan.

In the same Proceedings, Dr. Peter Schmidt of St. Petersburg dis-

cusses the huge Japanese Snail-fish, Trismegistus owstoni, and con-

390 THE AMERICAN NATURALIST [Vor. XL

cludes that its peculiar prickles do not justify generic separation from

Liparis.

In the Smithsonian Miscellaneous Collections (vol. 45, 1904), Hemi-

barbus joiteni, a large chub from China, is described by Jordan and

tarks.

In the a of the United States National Museum, (vol.

28, 1905), Dr. C. H. Gilbert and Surgeon J. C. Thompson discuss

certain rare fishes collected by Dr. Thompson in Puget Sound. Two

new species, both sculpins, are described: Stelgidonotus latifrons,

and Malacocottus kincaidi, the first a type of a new genus. Artedius

asperulus Starks proves to be the young of Astrolytes jenestralis.

In the same Proceedings, Messrs. Jordan and Starks discuss the

fishes collected by Pierre L. Jouy on the coasts of Korea. Seventy-

one species were obtained, a considerable number of which are new

to science. The shore fishes are essentially those of Japan; the river

fishes are nearly all new to science and of Chinese types.

In the Annotationes Zoölogie@ Japonenses, (vol. 5, 1905), Hans

Sauter of Yokohoma describes a new fish from Japan, of the family

Ateleopodide, under the name of Ijimaia döfleini. The genus Ijimaia

differs from Ateleopus in the rather slight character of the shortened

ventrals, and in the position of the mouth.

In the Sitzungsbericht der Gesellschaft der naturforschender

Freunde, 1905, Mr. P. Pappenheim discusses the genera of Stur-

geons, referring the Asiatic species of shovel nose, (Kessleria — Pseudo-

scaphirhyncus,) back to the American genus en There

is no obvious justification for this arrangement.

A. C. MacGilchrist (Ann. Mag. Nat. Hist., ser. 7, vol. 15, 1905),

describes a new genus, Dysalotus, (D. alcocki), allied to Chiasmodon,

from South Africa.

Other short papers in the same Annals are by Mr. C. T. Regan, of

the British Museum. From Tequesixtlan, Mexico, is described a

new goby, Cotylopus punctatus. — ai arg pauciradiatus

is held to be a valid species and a new “variety,” whatever that may

mean, is recorded from San Domingo de Guzman as Pseudoxipho-

phorus bimaculatus var. teniatus.

Another paper deals with the genera of Asiatic catfishes, Parexo-

stoma, Chimarrhichthys, and Exostoma. Still another describes

two new fishes from the Inland Sea of Japan, unfortunately without

indication of exact locality, and a new minnow from Lake Biwa.

No. 473] NOTES AND LITERATURE 391

In another paper, Mr. Regan defends his treatment of the genus

Arges against strictures made by Messrs. Evermann and Kendall.

Useful revisions of certain South American genera of Cichlidz are

also given by Mr. Regan. It is not clear that any useful purpose is

served by changing the spelling of Crenicara, to Crenacara. The

whole tendency in nomenclature at present is to let a name stand as

itis written. Purism breeds confu ion.

Dr. Rudolph von Ihering in the same journal describes four mailed

catfishes from Brazil, additional to those contained in the monograph

of Mr. Regan.

In the Revue Su sse, (vol. 13, 1905), Mr. Regan describes six new

species of fishes in the museum of Geneva. One of these, Sciena

(Bairdiella) bedoti is from Cuba.

In the Proceedings oj the Bombay Natural History Society, Mr.

Regan describes a number of new species from the Persian Gulf with

a series of excellent figures.

In the Comptes Rendus of the Sixth International Congress, 1904,

Dr. Jacques Pellegrin records a small collection of fishes from Lake

Tchad, the first made in these waters. Its fauna is, however, not dis-

tinct from that of the great rivers of Central Africa. Dr. Pellegrin

also describes the hatching of the eggs of the perch-like fish, Tilapia

galilea, in the mouth of the mother.

In the Report of the Commissioner of Fisheries for 1904, Ulysses

O. Cox gives a revision of the cave fishes, Amblyopside, of North

America, with figures of most of the species. At about the same

time, Dr. C. H. Eigenmann describes two new species of cave fishes,

(Biol. Bull. Ind. Univ., vol. 8, 1905). These are Typhlichthys

wyandotte, from Corydon, Indiana, and T. osborni from Horse Cave,

Kentucky.

In the Proceedings of the Washington Academy of Science, Dr. C. H.

Eigenmann and David P. Ward give an excellent monographie review

of the South American fishes constituting the family of Gymnotide.

A few new generic names are proposed.

Dr. Robert von Lendenfeld (Bull. Mus. Comp. Zoöl., 1905) describes

in detail the radiating organs of deep-sea fishes, with a series of admir-

able plates. These organs, known as luminous organs or glands,

are for the purpose of radiation of waves of light, ultra red, perhaps,

or in some cases of electricity.

392 THE AMERICAN NATURALIST [Vor. XL

In the Report on Norwegian Fishery Investigations, Dr. Robert

Collett describes the species taken in the cruise of the Michael Sars in

the North Sea. Valuable notes accompany the list of species. A

new subgenus, Bathyalopex, is proposed for Chimera mirabilis and

for the Japanese species, Chimera mitsukurii, in which the anal is

not notched.

In anothe paper, Collett describes a new lantern-fish, Lampadena

chavesi, from the Azores.

In two volumes, large quarto, under the title of A Guide to the

Study of Fishes, Henry Holt and Co. publish a general account of

fish life, fish structure, and fish classification by Dr. D. S. Jordan.

This work is doubtless the most elaborate yet published on this topic.

It is beautifully printed and fully illustrated, and the author has tried

to put into it all that he knows about fishes which can have an interest

to naturalists and to the cultivated public generally. Works of similar

scope but less detailed in their treatment, are Dr. Giinther’s Intro-

duction to the Study of Fishes and the volume on fishes in the Cambridge

Natural History, this last work appearing almost simultaneously with

Jordan’s Guide.

Dr. C. R. Eastman (Mém. Soc. Géol. de France, vol. 13, 1905)

treats exhaustively of the Eocene fishes of Monte Bolea in the Museum

d’ Histoire Naturelle de Paris. A number of new species are de-

scribed and figured. Not much account is taken of the questions of

priority, else the preoccupied name, Platyrhina, would not be used

for Discobatus of Garman, or Trygon for Dasyatis. Zanclus hardly

belongs to or even near to the Carangide, and Serranus, Apogon, and

Dentex are not nowadays Percide. But these are minor issues, in

comparison with the elucidation of this earliest of fossil tropical fish

faunas having a modern cast.

In the Report of the State Geologist of New Jersey for 1904, Dr.

Charles R. Eastman contributes a popular account of the significance

of fossil remains of fishes. This is followed by a description of spe-

cies found in the Triassic rocks of New Jersey, with photographic

plates of numerous species.

In the American Geologist, vol. 24, 1904, Dr. Bashford Dean shows

that the Permian fish, Menaspis, may be a Chimeeroid.

Mr. L. Hussakof (Bull. Amer. Mus. Nat. Hist., 1905), discusses

the fish called Dinichthys intermedius, and its probable traits in life.

An interesting and valuable biographical sketch of Peter Artedi,

the ‘‘father of ichthyology,’’ is published by Einar Lönnberg, as a

No. 473] NOTES AND LITERATURE 393

memoir in behalf of the Swedish Academy of Science. ‘‘Artedi was

the first to settle definitely the notion of genus in zoology and to make

clear the difference existing between species and variety, to demand

a classification on natural principles into classes, orders, ete., based

inter alia on comparative anatomical investigation." This address

marks the bicentennary of the birth of Artedi, March 10, 1705.

The seventh volume of the Cambridge Natural History treating

of the ‘‘Fishes, Ascidians, etc.," is a most substantial and valuable

contribution to our general knowledge of these groups. In this book

of 753 pages, the Hemichordata, are treated by Dr. S. F. Harmer,

the Ascidians and Lancelets by W. A. Herdman, the lower fishes by

Dr W. Bridge, and the Teleosts by Dr. G. A. Boulenger. The

excellent account of the structure and physiology of fishes is by Dr.

Bridge. Throughout the volume, the treatment of the subject is

accurate and dignified, though distinctly technical. The fossil forms,

represented by excellent plates, are placed in proper sequence with

the living forms. Modern researches in the osteology of fishes have

been carefully considered, and in general, more attention has been

given to the rules of scientific nomenclature, than in most general

_treatises on ichthyology. A series of small maps showing the geo-

graphical distribution of various groups is an excellent feature of the

work. By placing the Cyclize, Ostracodermi, and Arthrodira in the

appendix, Dr. Bridge is enabled to avoid any theory as to the actual

relationship of each. The Cladoselachide are regarded as the most

primitive of the known sharks, and the Crossopterygians as probable

ancestors of amphibians, Dipneustans, and the bony fishes, in accord-

ance with the carefully considered theory of Dr. Dollo.

The treatment of the Teleostei by Dr. Boulenger represents long-

continued studies on the part of an original and forceful worker. In

the main, the general views and the sequence adopted coincide fairly

with the classification current among American ichthyologists. This

is gratifying, as tradition at the British Museum leads along the old

Cuvierian lines. The adoption of the theory of development does

away with the sequence which would place the perch as a typical fish

at the head of the series. The head of the series of bony fishes must

be the most primitive of these forms, and this, all now agree, must be

found in the herring-salmon group, called by Cope, Isospondyli.

From these generalized forms, we proceed to those more and more

complex. In this, there is no longer much doubt as to the main facts,

but there is room for great play of individual whim or taste in the

relative sequence of the branches. As a book classification must be

394 THE AMERICAN NATURALIST [Vor. XL

linear, the sequence can be natural in only a very, “slight degree at

the best. Dr. Boulenger prefers a less minute subdivision of families

than that adopted by Gill, Cope, and American writers generally.

This matter is not a vital one. There is something to be said on

either side. In a subdivision too minute the close relation of forms

may be lost sight of. On the other hand, by attaching aberrant forms

to the nearest family, we often destroy the naturalness of our groups.

As the suborders of Teleostean fishes are very unequal in value, very

much intertangled, and for the most part incapable of trenchant defi-

nition, Dr. Boulenger has been no more and no less successful than

others in defining them. The fault lies with Nature, who has not

done her part in the elimination of interlocking forms. ‘The emphasis

laid on the characters of the Ostariophysi is a step forward, as is also

the separation of the Symbranchii from the eels. There seems to

be no very good reason for using the term Malacopterygii for the

group defined as Isospondyli, as the great majority of the species

called Malacopterygii by Cuvier belong to the Ostariophysi and

Haplomi. The Haplomi of Boulenger is not a natural group, and

more extended study is necessary before we can draw the line accu-

rately between Isospondyli and Haplomi. The suborder Heteromi

of Boulenger seems to be unduly extended. The Catosteomi (Lam-

pris and sticklebacks) form an unnatural association, as Dr. Boulenger

(p. 627) seems about ready to admit. It appears, however, reason-

able to place the pipe-fishes in the same suborder with the stickle-

backs. ‘The Percesoces of Boulenger can hardly hold together long.

Ammodytes is a jugular fish, the Scombresoces diverge in the direction

of the Haplomi, while Polynemus, Chiasmodon, Stromateus, and

Anabas, all diverge widely from the mullets and other typical Per-

cesoces, and each in its own way. As a matter of fact, the Percesoces

at the best are no farther from the true Acanthopterygii than is Beryx

or Gobiesox or Callionymus. Percopsis, placed by Boulenger with

the Haplomi, is better separated from everything else, than the mem-

bers of the Haplomi-Catosteomi-Percesoces-Acanthopterygian series

are from each other. But this is the fault of Nature, not of the syste-

matists. Aphredoderus, as Starks has shown, is not a Berycoid fish.

The group Zeorhombi (the John Dory and the flounders), indicates

an association not yet proved, but on the whole the allocation of fami-

lies and genera among the perciform types is very satisfactory. The

“new University" of Cambridge, to borrow the phrase from the pre-

face to the work, is to be sincerely congratulated on this additional

contribution to sound science and scientific method.

(No. 472 was issued April 16, 1906.)

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THE

AMERICAN NATURALIST

Vor. XL June, 1906 No. 474

OBSERVATIONS AND EXPERIMENTS ON. DRAGON-

FLIES IN BRACKISH WATER

RAYMOND C. OSBURN

WHEN we consider the great variety and extent of adaptation

among the insects, and especially when we recall the multitude of

aquatie and semi-aquatic species, it seems rather remarkable that

none of them has been able to take up marine life. Halobates,

one of the Hemiptera, is truly oceanic, a few species of Diptera

are known to live in sea water during their larval stage, a few

larval forms have been found below high tide where they would

be exposed to the sea water for a portion of the time, and a num-

ber of adult insects, chiefly beetles, range the shore finding their

food when the tide is out.

In brackish water, however, many species are regularly found,

belonging to nearly all the insect orders. It is a noteworthy fact

that nearly all of these are more commonly found breeding in

fresh water and are not peculiar to brackish water conditions.

While the occurrence of dragonfly nymphs in brackish ponds

must have been noticed many times by observing naturalists,

references in literature are exceedingly scant. Mr. E. A. Schwartz

(“ Preliminary Remarks on the Insect Fauna of the Gt. Salt Lake,

Utah," Can. Ent., vol. 23), found nymphs living in a mixture of

salt and sulphurous or fresh water about Gt. Salt Lake, but

adds: “ The same species were also seen at Utah Lake, which is |

fresh water"; and the eminent authority on the dragonflies, Dr.

P. P. Calvert in his “Catalogue of the Odonata of the Vicinity of

Philadelphia" (Trans. Amer. Ent. Soc., vol. 20, 1893) makes the

395

396 THE AMERICAN NATURALIST [Vor. XL

following statement: “No Odonate nymphs are known to live in

salt water, but probably some coast species, such as Ischnura

ramburii and Micrathyria berenice live in that which is brackish.”

The writer’s attention was first attracted to the presence of

dragonflies in brackish water by the discovery that many common

Pacific Coast species were breeding abundantly in a slightly

brackish pond near Victoria, British Columbia. No estimate of

the salinity could be made but it was slight. Again at Wood’s

Hole, Mass., many common forms were also found living in brack-

ish ponds of varying density. The following list of species noted

breeding in brackish water will serve to show what a variety of

those ordinarily breeding in fresh water may, if occasion require,

live equally well to all appearances in slightly salt water. At

Victoria, B. C.: Enallagma carunculatum, Ischnura pervarva, I.

cervula, Aeschna californica, Sympetrum madidum, Mesothemis

simplicicollis var. collocata, Libellula quadrimaculata, and L.

forensis. At Wood’s Hole, Mass.: Lestes unguiculatus, L. rec-

tangularis, Nehalennia irene, Enallagma civile, Ischnura verticalis,

Anax junius, Leucorhinia intacta, Micrathyria berenice, Sympetrum

rubicundulum, Libellula pulchella, L. auripennis, and Plathemis

lydia. These records were obtained partly by identification of the

nymphs, partly by rearing the imagos, and partly by collecting the

young imagos just after their transformation. The Wood’s Hole

list represents only seven weeks collecting in July and August and

in a very restricted locality so it is highly probable that the list

represents only a few of those that may be found in brackish

water. Of the above species, only one, Micrathyria berenice, is

limited in its range to near the coast, and as it also breeds in fresh

water in the same region it can hardly be said to be a typical

brackish water species.

In order to determine the salinity of water in which dragonflies

may live the following experiments and tests were made at Wood’s

Hole during the summer of 1905. As the work had to be pursued

for the most part at odd moments my observations are not as

complete as could be wished, and yet they are full enough to be

quite significant. My thanks are due the U. S. Bureau of Fisheries

for the opportunity to carry on the work while connected with the

Wood’s Hole Station as temporary scientific assistant.

No. 474] DRAGONFLIES IN BRACKISH WATER 397

In the first place, a series of salinometer tests of the water in all

the ponds in which dragonfly nymphs were found, was made.

Water from four such ponds on Nonnamesset Island and from

three on the mainland was tested and in none of them was the

density greater than 1.0015, while the average was about 1.0008.

These tests were made at a temperature of 72° Fahr. and as the

figures have not been reduced the actual density would be con-

siderably greater. It will be noted, however, that water of such

density contains but little salt in comparison with that of sea water,

which has an average density of 1.026. One pond examined had

a density of 1.015 at 72°, but, though dragonflies of several species

were seen about this pond, a careful examination revealed no

dragonfly nymphs living in the water and it is a safe assumption

that the adults came from less saline ponds in the vicinity. Even

if oviposition should take place under such conditions it is highly

probable, as will be shown by the experiments to be discussed,

that no eggs would develop.

Next, the experiment of placing nymphs in saline solutions of

various densities was tried. Chiefly the nymphs of Lestes un-

guiculatus, an Agrionid, were used. These were taken from a

pond of the density of 1.0012. Those placed in water which was

entirely fresh showed no ill effects from the change, and the same

is true of those put into saline solutions of low density, up to about

1.003. Beyond this point the larvee showed increasing signs of

irritation. In solutions at 1.005, 1.0075, and 1.01 the nymphs at

first wriggled and swam violently, tried to climb up the sides of the

aquaria and otherwise gave evidence of much irritation, but they

apparently became inured to it after a day or so and lived as well

in these solutions as in that in which they were found. Higher

solutions were always fatal. In sea water at 1.02 they lived only

a few hours, and at 1.015 they showed every sign of discomfort

and invariably died within a day or so.

The larve of Ischnura verticalis, also an Agrionid, of Anav

junius, an Aeschnid, and of several Libellulids, chiefly Sympetrum

rubicundulum, showed entirely similar results.

Further experiments on the development of the eggs in brackish

water yielded some interesting results tallying well with those

made on the nymphs. Eggs of Libellula auripennis Burmeister

398 THE AMERICAN NATURALIST [Vor. XL

were taken just prior to oviposition on July 16, 1905. "These

were placed in solutions of various densities at 75° F. as indicated

in the following table with the results noted :—

Density of water Result

BEREITEN ie N ee hatched July 30

Baer ee ee le oe

EI Dr PO wre ee Faea to hatch, partial dev Kipea

AME BR EN o “ mo development (?)

LÁ fd fd fe funk RE

EN o. a Er ee ae

A glance at the above table shows that the amount of salinity

from fresh water up to 1.010 had no effect whatever on the time

of hatching; all hatched out together 14 days after fertilization.

The 1.015 and 1.020 cultures were kept under exactly the same

conditions but neither developed to the point of hatching. In the

former considerable development took place, to the extent that the

main structures*of the larva were outlined, but in the latter no

indications of development could be observed except some cases

of questionable segmentation.

No differences could. be noted between the larve hatched in

1.010 and those hatched in weaker solutions or fresh water and

later experiments proved them to be equally hardy.

The young larve were now transferred to solutions differing

from those in which they had been hatched, in order to test their

resistance to density changes at this period. The results tally

remarkably with those on the older nymphs and with the hatching

experiments. Larve hatched in 1.010, 1.0075, and 1.005 solutions

when placed in fresh water showed no discomfort and lived as

well as those hatched in the fresh water, while, those hatched in

fresh water stood the change into the above solutions without any

noticeable effect. The attempt to run any of them into higher

solutions, however, always resulted fatally in a short time. In

1.015 they died in less than a day, in the 1.020 they were killed in

No. 474] DRAGONFLIES IN BRACKISH WATER 399

a few hours. Those hatched in the 1.010 solution had apparently

gained no further power of resistance but succumbed as quickly

as those from fresh water. "This test was repeated after two weeks

but with the same result, they still were overcome as readily as

when first hatched.

The above experiments indicate that there is in the Odonata

a very definite barrier to their assumption of marine life, and that

this barrier remains unchanged during the life of the individual.

That it is the same for all species has not yet been determined, and

it may be that forms such as Micrathyria berenice which are limited

in distribution to the coastline have a higher limit than those

species which occur in the interior only. As to the nature of the

barrier we are entirely in the dark. It may be that the eggs and

nymphs of Odonata are able to prevent the osmosis of salt in

solution up to a certain point, but it seems more probable that the

metabolism is interfered with only by salt in solution above a

certain density. Whether other groups of insects are similarly

restricted is also unknown.

COLUMBIA UNIVERSITY

CONTRIBUTIONS FROM THE ZOÖLOGICAL LABORATORY OF

THE MUSEUM OF COMPARATIVE ZOÖLOGY AT HARVARD

COLLEGE. E. L. MARK, Director. No. 178.

REACTIONS OF TUBULARIA CROCEA (AG.)

A. S. PEARSE

WHILE the reactions of sea anemones and of jelly fishes have

been carefully studied, comparatively little is known of those of

hydroids. In fact, the only recent paper which deals primarily

with this subject is one by Torrey (:04) on Corymorpha palma.

He found that this hydroid gives well marked reactions to gravity

and mechanical stimulation, but does not respond to chemical

stimulation. |

The work upon which the present paper is based was under-

taken at the suggestion of Professor G. H. Parker, and the

experiments were carried on at the Laboratory of the United States

Bureau of Fisheries at Wood's Hole, Mass. My thanks are due to

the director, Dr. F. B. Sumner, for the courtesies shown me at the

Wood's Hole Laboratory and to the Museum of Comparative

Zoölogy for pecuniary assistance granted from the Humboldt

und.

The material, consisting of colonies of Tubularia, was scraped

from the piles of the wharf at the Fisheries Station and examined

in sea water within three hours of the time of collection. The

colonies are rather delicate and are easily rendered inactive or

illed by unfavorable conditions. Small portions of colonies, con-

taining from twenty-five to fifty polyps, were used in these experi-

ments.

The accompanying figure represents an expanded hydranth of

Tubularia crocea and a short portion of the stalk upon which it is

borne. In a resting hydranth the proximal tentacles (ta. pra.)

are bent slightly back toward the stalk (caul.) and remain motion-

less except for an occasional sudden movement toward the mouth

(os), after which they slowly return to their former position. The

distal tentacles (ta. dst.) are more active and are usually in motion,

401

402 THE AMERICAN NATURALIST [Vor. XL

bending back and forth singly or collectively. ‘The manubrium

(mab.) is ordinarily motionless, but may shorten or lengthen and,

when stimulated, is capable of bending even to such an extent that

the mouth is brought below the bases of the proximal tentacles.

The whole hydranth may be moved by the bending of the stalk,

but this action is not of frequent occurrence and it is apparently

not called forth in response to direct stimulation.

MECHANICAL STIMULATION

When a proximal tentacle is touched with a needle or pinched,

it bends toward the manubrium. The strength of the stimulus

influences the response. If the stimulus is weak, there may be no

reaction, but if it is strong, the whole circle of tentacles may close

up together and press against the manubrium. If the manubrium

or the distal tentacles are stimulated in a similar manner, the for-

No. 474] REACTIONS OF TUBULARIA 403

mer bends toward the point of stimulation and a few or all of the

distal tentacles wave about for a short time. If in this process

they touch some object, they then close up around the mouth.

When the stimulation is very strong, the manubrium shortens and

both sets of tentacles close up around it.

The hydranths will submit to considerable mechanical stimu-

. lation without reaction. For example, a stream of water forced

from a pipette upon an expanded individual will cause no move-

ment unless the current is rather strong.

If a proximal tentacle is pulled vigorously, the manubrium will

turn so that the mouth is brought toward the stimulated point and

the distal tentacles will open out. However, as each set of ten-

tacles may be made to react independently and without apparent

influence on the other set, it seems probable that in this case the

manubrium is.strained and thus stimulated directly.

The reactions described above are doubtless helpful to the animal

in securing food, though they are not perfectly adapted to this pur-

pose. They are not very accurately adjusted to the gathering of

food, for the proximal tentacles will always move toward the mouth

even when the point of stimulation is on the outer face, in which

case they move directly away from what may be food.

CHEMICAL STIMULATION

When a proximal tentacle is touched with a piece of meat at any

point, it bends toward the mouth. The meat, if it is on the inner

face of the tentacle, is pressed against the mouth for a time and

then the tentacle slowly returns to its former place. All the proxi-

mal tentacles often close up in the presence of meat, but those in

contact with it react first and remain closed after the others have

opened out, which they usually do quickly. If meat is placed very

gently on the proximal tentacles, no reaction takes place and it falls

off or remains resting upon them. Sometimes when meat is placed

upon them, the bending reaction takes place, but this is so feeble

that the meat does not move far enough to reach the distal tentacles

and in such cases tbere is no movement of the manubrium or distal

tentacles. When meat comes in contact with the distal tentacles,

404 THE AMERICAN NATURALIST [Vor. XL

however, they bend outward and the manubrium turns them to-

ward the stimulated side. If they then touch the meat, they close

up around the mouth.

These reactions make it appear as though the procuring of food

depended wholly upon mechanical stimulation, as Torrey has

claimed in the case of Corymorpha; but the following experiments

have led to a somewhat different conclusion. When a grain of

sand is placed on one side of a hydranth,— being allowed to rest

upon the proximal tentacles and to touch the distal ones, —and a

piece of meat is placed in a corresponding position on the opposite

side, the manubrium almost invariably turns toward the meat and

the distal tentacles open out. In another experiment meat juice

was extracted and filtered. This filtrate has a milky appearance

and can easily be seen in water. When it is allowed to flow gently

from the mouth of a pipette on the proximal tentacles, no reaction

takes place, but as soon as it touches the distal tentacles they ex-

pand and the manubrium bends toward the stimulated side. To

prove that these reactions are not due to mechanical stimulation

produced by particles of solid matter or by currents, the same ex-

periment was tried using powdered carmine in sea water instead of

meat juice.

In 15% of the trials (685) with carmine water the mouth was

turned toward the stimulated side and the distal tentacles opened

out, but when the meat filtrate was used upon the same individuals

the turning and opening-out reactions took place in 82% of the

trials (717).

A third experiment points in the same direction. If the distal

tentacles of an active hydranth are touched several times with a

needle, they close tightly over the mouth. If, after a moment,

they are touched again with the needle, they remain closed for

some time; but if as a second stimulation they are touched in the

same.manner with a piece of meat instead of a needle, they at once

open out and wave about.

From the above experiments it is reasonable to conclude that

the distal tentacles, and perhaps the manubrium, are sensitive to

a substance or substances contained in meat juice, while the

proximal tentacles are not.

The effect of other chemical substances was tested without ob-

No. 474] REACTIONS OF TUBULARIA 405

taining particularly significant results. When treated with dilute

onion juice, quinine solution, or acetic acid, the hydranths closed

up for a time, and if the solution was strong enough, they were

killed. These substances, unlike meat, produce the same reac-

tions as does strong mechanical stimulation.

Filter paper soaked in meat juice, onion juice, clove oil, or oil of

bergamot and held near the hydranth caused no reaction of any

part, the animal being apparently insensitive to the resulting very

dilute solutions.

THERMAL STIMULATION

Colonies of Tubularia were placed in glass dishes and the effect

of a rise or fall in temperature noted. When the temperature of

the water was raised above 25° C. most of the animals were inactive,

though two individuals turned the proboscis and opened out the

distal tentacles when, at 27.5° C., they were touched with meat.

No animal, after having been heated to 26° C. and then cooled again

to normal’ temperature, survived and reacted normally. When

the water was cooled to about 10° C. most individuals became

inactive to meat, though a few reacted to this form of stimulation

even at0°C. Probably the colonies survive any temperature down

to near freezing, as individuals which had been for half an hour

in water which was frozen (-2.2° C.) at the bottom of the dish

and had a temperature of 1.5° C. at the top, gave the usual reac-

tions thirteen hours later at a normal temperature. In no case

did animals survive actual freezing in the ice. In extreme changes

of temperature, the proximal tentacles cease to react before the

distal ones, and this is what might be expected from the relative

sensitiveness of the latter.

Local thermal stimulation was attempted with a bent capillary

heated tube, or cooled by a current of water such as Mast (:03)

used in his experiments on Hydra. The tube was held near the

hydranth but not allowed to touch it. A cold tube (ice water)

caused no perceptible effect on any part of the hydranth, but a hot

! The average temperature (readings at 8.00 a. m. and 5.00 P. m.) at

Wood's Hole during the first ten days in August, 1905, was 19.8? C.

406 THE AMERICAN NATURALIST [Vor. XL

tube caused a restless indeterminate movement of the distal ten-

tacles.

PHoTIc STIMULATION

No extensive experiments with light were attempted. Colonies

were placed in the dark and then suddenly illuminated by a 16 c. p.

electric light, or a shadow was cast over them after they had been

illuminated for some time, but no observable reactions occurred in

either case. It was also noted that the colonies grew just as abun-

dantly on the sides of the piles most exposed to light as on those

least exposed.

SUMMARY

1. The proximal tentacles of Tubularia crocea react to mechan-

ical stimulation by bending toward the manubrium.

2. The distal tentacles react to mechanical and chemical stimu-

lation by bending toward or away from the mouth, and this action

may be accompanied by a bending of the manubrium toward the

stimulated side.

3. Apparently no part of the hydranth is sensitive to very dilute

solutions of meat juice, onion juice, and oil of cloves or heed Sra

(so called “odorous” substances).

4. The minimum temperature at which reactions occur is 0? C.

and the maximum about 26° C.

5. Sudden change from strong light to shadow or from dark-

ness to strong light has no apparent effect upon the animals.

No. 474] REACTIONS OF TUBULARIA 407

BIBLIOGRAPHY

Agassiz, L.

’62. Contributions to the Natural History of the United States of

America. Boston, 4°, vol. 4, viii+380+12 pp., pls. 20-35.

ALLMAN, G. J.

"711-72. A Monograph of the Gymnoblastic or Tubularian Hydroids

London, 4°, xxiv + 450 pp., 23 pls.

Mast, 8. O.

:03. Reactions to Temperature Changes in Spirillum, Hydra, and

Fresh-water Planarians. Amer. Jour. Physiol., vol. 10, no.

pp. 165-190

NurrING, C. C.

:01. The Hydroids of the Woods Hole Region. Bull. U. S. Fish

Comm., vol. 19, 1899, pp. 325-386, 105 figs.

PARKER, G. H.

'96. The Reactions of Metridium to Food and other Substances.

Bull. Mus. Comp. Zoöl. Harvard College, vol. 29, no. 2, pp.

109-119.

‘Torrey, H. B.

: 04. en Studies on Corymorpha. I. C. palma and Environ-

Jour. Exp. Zoöl., vol. 1, no. 3, pp. 395-422, 5 figs.

YERKES, R. M.

:02°. A Contribution to the Physiology of the Nervous System of

the Medusa Gonionemus murbachii. Part I— The Sensory

Reactions of Gonionemus. Amer. Jour. Physiol., vol. 6, pp.

434-449.

Yerkes, R. M.

:02". A Contribution to the Physiology of the Nervous System of the

Medusa Gonionema murbachii. Part II.— The Physiology of |

the Central Nervous System. Amer. Jour. Physiol, vol. 7,

no. 2, pp. 181-198.

PRESSURE AND FLOW OF SAP IN THE MAPLE!

K. M. WIEGAND

Ir ıs with some hesitation that a contribution is here attempted

to the already voluminous literature regarding the ascent, flow,

and pressure of sap in trees. Work on the maple has reached

such a point, however, that it seems desirable to review critically

our present knowledge to see which, if any, of our various theories

are tenable, in how far, and why.

GENERAL ACCOUNT OF CONDITIONS ACCOMPANYING FLOW

In recent years the phenomenon of bleeding in plant tissue has

come to be recognized as a very general one.” It has been found

to occur in tissues widely different in nature, and under widely

different conditions. Perhaps the bleeding of the root, accom-

panied by root-pressure, is the best known example of this phe-

nomenon. ‘The bleeding of trees in the spring attracted the

attention of the early investigators, and has been the subject of

considerable wonder and mystery ever since. Although it is a

common phenomenon, we know comparatively little about the

cause.

In late winter and early spring, if the maple is “tapped,” that

is, bored with an auger, sap will flow from the wound in consider-

able quantity, the flow being dependent very largely upon the

temperature. Some other trees that bleed in the same way as the

maple, though usually not to so great an extent, are Juglans

cinerea, Cladrastis, Nyssa, and sometimes Prunus serotina. Later

in the spring, just before vernation, the birch and grape bleed

profusely, and, to a lesser extent, also Ostrya, Hicoria, Alnus,

Malus, Crategus, Salix, Ulmus, and perhaps a few other trees.

Investigation of these various trees has shown that they fall

‘Contributions from the Department of Botany of Cornell University, No.

2? Wieler, A. “Das Bluten der Pflanzen." Cohn’s Beiträge, vol. 6, p. 1, 1892.

409

410 THE AMERICAN NATURALIST [Vor. XL

into two very definite groups as regards the bleeding phenomena,

with a different source, and perhaps different cause, for the bleeding

in the two cases. Those which, like the maple, bleed early in the

spring and are dependent upon temperature, constitute one class,

while the late-bleeding ones, like birch and grape, which are not

intimately dependent upon the temperature, constitute a class by

themselves. This paper is concerned entirely with the first of

these two groups, and only a few words will be said about the other

group at the close, as a matter of comparison.

Branches cut from certain trees at a low temperature and brought

into the warm laboratory often show bleeding from the cut sur-

face. Clark tested sugar maple, white birch, elm, hickory, button-

wood, chestnut, and willow in this respect. The maple soon began

to bleed at the rate of 24 drops per minute, while the buttonwood

bled 11 drops, and the hickory exuded a little very sweet sap,

precisely as in spring. The birch, chestnut, elm, and willow did

not flow at all, and were not even moist on the cut surface. I

have often repeated this experiment with maple branches. By

passing the branch between the flues of a radiator a very vigorous

exudation can frequently be obtained. The trees that bleed in

this way are usually those in which the vessels are comparatively

saturated with sap. According to Clark, a mercurial gauge at-

tached to the end of a frozen branch of sugar maple indicated

pressure and suction when the temperature was raised and lowered

precisely as it would have done upon a maple tree during the

ordinary alternations of day and night in the spring of the year

when the sap is flowing.

LATE Winter FLow IN MAPLE AND OTHER TREES

Considering its importance from an economic standpoint, the

subject of maple-sap flow has received comparatively little atten-

tion. In 1874 and 1875 Clark! published the results of several

years of detailed work upon the maple. "These two papers really

‘Clark, W. S. The Circulation of Sap in Plants (A lecture before the Mass.

State Board of Agric. at Fitchburg Dec. 2, 1873). Boston, 1874.

Clark, W.S. "Observations on the Phenomena of Plant Life.” 22d Ann.

Rep. Mass. State Board of Agric., Boston, 1

No. 474] SAP FLOW IN MAPLE 411

laid the foundation for our scientific knowledge of the bleeding

in these trees. Not until 1903, after 28 years, did the next im-

portant contribution to the problem appear. This was the bulletin

from the Vermont Experiment Station,’ and here in one hundred

and forty-one pages, are extensive records of experiments and

observations of the most painstaking sort, representing the work

of several men during a number of sugar seasons. It is the latest

and most important contribution yet made to our knowledge of

the subject. The last thirty pages of this bulletin are devoted

exclusively to tables recording the results of typical experiments

and determinations along the various lines of research.

In the succeeding pages I shall first attempt to present in con-

densed form the main facts connected with maple-sap flow as

determined by these investigators and then turn to a consideration

of the various theories in detail. In this review my own observa-

tions are added only when they are at variance with the others.

Both Clark and the Vermont workers found slight suction ob-

taining in the maple tree all through the growing season. "This

negative pressure, averaging 2.25 kg. per sq. in. fluctuated some-

what during the season, and to a slighter extent it also showed a

daily periodicity. The latter, however, was not marked. Suction

continued in most cases throughout midwinter until February or

March. Under certain weather conditions, however, the suction

frequently lessened until the zero point was reached and positive

pressure resulted. During most of the time until March the

tension of any sort was almost nil Then the great oscillations

which are characteristic of the sugar season, and which are closely

related to the phenomena of sap flow, set in to continue until the

buds began to swell. After the buds swelled, the pressure quickly

disappeared. Sugar has been made from the maple, according

to Clark, in all the winter and spring months from October to May,

but, except in the spring, always in small quantities. The flow

is said to be better in October and November than later, and rarely

occurs in December, January, and early February except on very

warm days. During the warm December of 1905 on several

1 Jones, C. H., Edson, A. W., Morse, W. J. “The Maple Sap Flow." Ver-

mont Agric. Exp. Sta., bull. 103, Dec. 1903. à;

412 THE AMERICAN NATURALIST [Vor. XL

bright mornings following cold nights, sap flowed in considerable

quantity from the stubs where branches had been pruned from

maple shade trees on the Cornell campus. In the daily papers

were reports of sugar having been made during that same month.

'The best sap days are those in which a bright sunny morning

with rising temperature follows a frosty night. The flow is greatest

early in the morning, decreases gradually as the day advances,

and ceases altogether during cold nights. It is not a daily perio-

dicity, however, since on many days no sap flows, while again the

flow may continue all night. It seems necessary that the rising

temperature should cross the 0? C. line in order that there should

be a good “run” of sap. If the-temperature remains for several

days above this point or for several days below it, the flow will

rapidly diminish, and in from 24 to 36 hours cease altogether. ‘The

trees will then “dry up” and have to be retapped, even though the

temperature fluctuates considerably. Hence comes the popular

ye that the roots must freeze at night in order to obtain a good

’ the following day. Depending upon the weather, there-

fore, the sap flow is usually broken up into periods known as

" runs." de swelling of the leaf-buds marks the end of the flow,

or “season.” If the day be too bright after the frosty night, the

flow is apt to start briskly and soon lessen or cease, or if the wind

be high the flow is soon checked. If the sky be overcast and the

air has warmed slightly, a satisfactory run is likely to ensue.

Alternate freezing and thawing,— moderately warm days preceded

by freezing nights,— are the ideal meteorological conditions which

promote the flow. Other things being equal, the flow is usually

greater on southern exposures, since there the temperature ex-

tremes are greater.

A manometer attached to a bleeding maple tree shows that a

considerable pressure exists within the tissues of the wood. It is

this pressure which causes the outflow of sap, and which is the

primary phenomenon to be considered. During the best sap days

the pressure may rise as high as 6.5 to 10kg. per sq. in., but is usually

less. The pressure is highest on warm sunny mornings after a

frosty night, and rises very rapidly after the first sunlight strikes

the tree, so that on ordinary bright sap days it has reached its

maximum at nine or ten o'clock. After that it gradually decreases

No. 474] SAP FLOW IN MAPLE 413

toward nightfall. The time of highest pressure does not there-

fore coincide with that of highest temperature, but often precedes

the latter by several hours. The maximum pressure on a good

day usually occurs about one and one half hours after commencing

in the early morning. If the following night is also cold, then all

through the night a moderate suction will obtain again, to be

followed by a similar abrupt rise the following morning. In one

case, Clark read on the manometer at 6 A. M. a suction sufficient

to raise a column of water 7.89 meters high, while as soon as the

sun shone upon the tree the mercury suddenly began to rise so

that at 8.15 a. m. the pressure outward was enough to sustain a

column of water 5.63 meters in height, a change represented by

more than 13.5 meters of water. On another morning the change

was still greater representing 14.45 meters of water. If the

night remains warm preceding a thaw, the fall of pressure will

be much less rapid, and a moderate pressure may continue all

through the night gradually vanishing during the following day.

After several days of thaw, suction may obtain most, if not all of

the time. If the temperature remains below freezing, suction

may exist for several days until the weather warms. There is

much to indicate that the normal condition in the maple at this

period is one of suction.

A rise of only a few degrees will often cause very great pressure

if the rise passes the zero point Centigrade. On the other hand

there may be considerable fluctuation in temperature without

great fluctuation in tension. This happens when the temperature

does not cross the zero line. The pressure fluctuations are greatest

early in the season. During the day, pressure forces into the

tap-hole all the sap located in the adjacent tissue. ‘The suction

which ensues on freezing nights possibly draws more sap into

these tissues, and this in turn is forced out when the tree warms

up again. The entrance of air is hindered by the impermeability

of the membranes.

It was found in Vermont that trees so placed that the morning

sun shone on the top first, showed pressure there before in the

lower trunk. On a certain day when there were alternate periods

of bright sun and clouds, the gauges fluctuated very markedly.

Two pressure gauges were placed at a distance of twenty feet

X THE AMERICAN NATURALIST [Vor. XL

(6 meters) from each other on an eighteen-meter tree, one being

near the ground. As a general rule the lower gauge responded

first, held its pressure longest, and fluctuated more. It showed

more pressure during the day and more suction at night. 'The

higher up the gauge, other things being equal, the less the pres-

sure. Sap conditions began first in the twigs and external layers

. of the wood, gradually passed to the deeper tissues and lower

parts, ceasing again in the same order. Clark, on the other

hand, laid emphasis on the fact that the greatest suction as well

as the greatest pressure was exhibited by the gauge at the top of

the tree, but his tables show that this was very unusual. In

general, his upper gauge registered much below the lower and

fluctuated no more than did the latter. In one case Clark found

that on the 19th of April the upper gauge showed little or no

pressure while the lower one still indicated a pressure of about

seven kilograms. In good seasons and good sap-spells the pressure

directed downward in the trunk exceeds that directed upward.

Later in the season the reverse may be true. Both pressure and

suction are greater in the outer than in the inner tissues until late

in the season. The outer tissues respond more quickly to tem-

perature changes, and the pressure changes here precede those in

the inner wood (hole 13 em. deep in a tree 60 cm. in diameter) by

about one hour. One depth might show pressure or suction while

the other showed the reverse.

Pressure is not readily transmitted radially, in fact the trans-

mission in this direction is very slight indeed. The lateral trans-

mission of pressure is also very slight, not much more than three

millimeters, but diagonally it is transmitted quite readily. Two

years' trial in Vermont showed that a 4.5 kg. pressure under some

conditions is transmitted through 244 cm. of distance. Smaller

pressures are not transmitted so far. It seems probable that the

pressure traverses the tissue entirely by means of the tracheæ. If

two tap-holes are made, one in a vertical line above the other,

and either one is opened, the fall of pressure in the other is abrupt

at first but after a short time ceases, and is proportional to the

distance between the holes. The remaining pressure represents

the resistance of the intervening tissue to the transmission of

pressure. In one case a hole bored 122 cm. above a gauge in-

No. 474] SAP FLOW IN MAPLE 415

dicating 6.8 kg. pressure caused a drop of 3.2 kg. before a stop-

cock could be inserted.

The sap flow varies in quantity with the pressure, so that a

separate discussion of its characteristics is scarcely necessary. Some

points, however, may be noted. On good sap days the quantity

is often great, being as much sometimes as 12 liters in 10 hours. In

some exceptional cases a flow of 20 liters per day has been re-

corded. Usually the flow is much less, 10 to 12 liters a day being

an average flow for a moderately good sap day. According to

the Vermont Bulletin it seems probable that a high registered

pressure is not absolutely necessary to a good flow of sap, but

that less pressure with longer duration will give equally good

results. The rate of flow seems to depend also upon the amount

of sap present in the wood around the tap-hole as well as upon

the pressure behind it.

In general the flow is greatest near the ground. Clark inserted

a spout at the usual height into a healthy maple which had never

been tapped, and fifteen meters above this another spout was set

into the trunk where it was 13 em. in diameter. In addition, a

limb 10.6 meters from the ground was also cut off where it was

2.5 cm. in diameter. In several hours the lower spout had bled

2.7 kg. of sap, the limb 56.7 gm., and the upper spout not a drop.

Similar experiments with other trees gave like results. Both

Clark and the Vermont workers found the down flow, as well as

the down pressure, greater especially at the ordinary height of

tapping. At both places, too, it was found that if an incision is

made into a tree the sap will flow from the upper side of the cut

and not from the lower unless late in the season. In late spring

the flow is usually from both surfaces. In other words the flow

is down from above in the maple, not up from the roots. Clark

found that a severed tree would bleed profusely from the cut

surface while the stump remained nearly dry. In Vermont itwas

found that in many cases severed twigs that started to bleed very

early in the season frequently ceased before the flow from the tap-

hole diminished very much. Lithium chloride inserted in the

tap-hole showed that at times, at least, sap under pressure

moves in the vicinity of the outlet hole at the rate of from 5 to

15 em. per minute.

416 THE AMERICAN NATURALIST [Vor. XL

Clark found that pressure from the root during the sugar season

was never more than very slight. Usually there was suction in the

root throughout this period. At the Vermont Station the results

were similar, the suction in one case being as much as 2.7 kg.

There was a very slight fluctuation, however, between day and

night as in nearly all roots. In no case was there a flow of sap

from the root until late in April at the time when other trees bleed

from the root. The root therefore as a source of bleeding in the

maple is out of the question.

'The sap of the maple is composed mainly of water with a few

substances in solution. Of these, cane sugar is the most important,

being present in from 1 to 5% concentration. At first the sap is

a water-clear, slightly sweet fluid, but as the season progresses

the flow tends to lessen and the sap is apt to thicken and become

cloudy or even somewhat slimy at times. Besides sugar there are

usually small quantities of proteids, of mineral matter, more

especially of lime and potash, and of acids mainly malic. ‘Traces

of reducing sugars are sometimes found, usually toward the last

of the season. The sap from a tap-hole at ordinary height is

considerably richer in sugar than the sap from the root, and also

richer than that from taps higher up in the tree. The percent of

sugar is also greater in sap from near the surface of a tree trunk

than from deeper in the wood. There is some reason to believe

that the actual distribution of stored material during the winter

(starch and sugar) follows these conditions closely with less stored

starch in the root than above ground, and less in the top than in

the trunk, but accurate determinations have not been made. In

Vermont it was found that at the beginning of the season sixty

percent of the sugar came down from above. At the close of the

season only about 39% came from the same source. There

seemed to be a slight diurnal fluctuation in the percent of ER

it being slightly greater toward nightfall.

The water content of the wood during the bleeding season

varies from 30% to 55%. After the leaves come out it falls to

from 19 to 30%. The Vermont workers found the relative amount

for root, trunk, branch, and twig to be 29, 30, 34, and 37 respec-

tively, but variations were so wide that the value of the series of

averages is open to question.

No. 474] SAP FLOW IN MAPLE 417

The gas content of maple wood was found by the Vermont

workers to be about 24% of the volume of the wood. This gas

consists largely of oxygen, carbon dioxide, and nitrogen, which

are either produced by metabolism or have passed in from the air.

During the late winter of 1904 I made a number of observations

concerning the disposition of the gas in the wood of a number

of trees, and the results may here be added. Sections were made

with a razor either under water or under oil, and mounted in the

medium in which cut. Looking quickly through the microscope

. before changes could occur, the disposition of the bubbles of gas

could be quite readily ascertained. It was found that in the maples

the vessels contained felatively little gas, sometimes appearing

saturated with sap, while the wood fibers usually contained a large

quantity of gas. In some cases the latter were nearly filled with

gas, in others only a part of them filled, and in a few specimens

of sugar maple I could find no gas in any part of the section.

Nyssa and Cladrastis showed little gas in the vessels during the

bleeding season, and little in the fibers. Juglans showed little in

the very large vessels while the fibers seemed always to be filled

with gas. The other trees examined showed more gas than sap

in the vessels.

The following table gives the results in detail:—

a. Sectioned under water, and under oil

Acer pseudoplatanus. Considerable gas in vessels especially near cortex;

gas in wood rs.

Acer saccharum. No gas in inner vessels, possibly a bubble in outer;

gas in fibers. Bled in room.

Acer saccharinum. No gas could be found in vessels of this specimen;

gas in fibers. Branch bled in room.

Eid platanoides. No gas found in vessels of this specimen ; plenty in

ges tartaricum. Gas in vessels near bark, elsewhere none found; gas

in fibers. Branch became damp in room and bled a few dri if heated

on radiator.

Acer insigne. Rarely a bubble in vessels; gas in fibers. Branch bled

a little in room, more on radiator.

Acer campestre. Considerable gas in vessels; gas in fibers. Became

damp only on radiator.

418 THE AMERICAN NATURALIST [Vor. XL

Juglans cinerea. Little gas in vessels, but fibers filled with gas.

Branches bled on radiator.

Nyssa sylvatica. Wood quite highly saturated; little gas in either

vessels or fibers. Bled on radiator.

Cladrastis lutea. Same as Nyssa. Bled on radiator.

b. Sectioned under oil

Salix fragilis. Large quantity of gas in vessels and fibers. Not even

damp on radiator.

Catalpa speciosa. Same as Salix.

Populus dilatata. Vessels almost full of gas. Not damp on radiator.

Ulmus americana. Same as Salix.

Fraxinus americana. Full of gas; could blow through a piece several

centimeters long. Not damp on radiator.

Vitis vulpina. Full of gas. Could blow through. Not damp on

radiator.

Prunus virginiana. Large quantity of gas in vessels. Not damp on

radiator.

Quercus alba. Much gas. Could blow through. Did not become

moist.

Regarding tree temperatures, it was found that in holes 8 cm.

deep they fluctuated less than air temperatures. According to

the Vermont Bulletin slight variations in outside temperature

caused little or no variation within the tree, which on many days

did not show a range of 2? C. Considerable variation in external

temperature, however, was followed in due time by corresponding,

though less marked, internal fluctuation. ‘Temperatures of -3? C.

and -2.5? C. were the lowest recorded during the sugar season.

Thermometers placed in 2.5 cm. deep holes on the north and south

side of a tree showed during the winter a lower registration on

the north side at all times except one day when the south wind was

blowing.

THE GAS-EXPANSION THEORY

About twenty-five percent of the volume of a maple tree is

occupied by gas during the sugar season (Vermont Bull.). The

presence of so much gas in the wood, together with its ease of

detection and its known expansive qualities, early led the attention

No: 474] SAP FLOW IN MAPLE 419:

of physiologists to this substance as a source of pressure, and until

recently it has seemed to many a very probable explanation.

In 1767, Du Hamel ' and Dalibard noticed that saturated wood

became lighter when heated in hot water because of the loss of a.

portion of the contained fluid, and regained nearly its original

weight when cooled, because of reabsorption. This was true

except when the water in the wood froze, in which case the wood

became again lighter in proportion to the frost.

Hartig; in 1853, experimented with normal living wood using

shoots of poplar, birch, etc. He found that, if these were taken

before sap flow had normally begun and warmed over a lamp or

in the hand, a small amount of sap would appear on the lower

surface. If the temperature was near that at which sap flow

normally appeared and the twig was normal, the excretion would

occur to a slight extent simply by the application of the finger to-

the bark.

In 1860 appeared the exhaustive paper of Sachs? who was the

first to put the gas-expansion theory on a firm scientific basis. A

cylindrical stick of Rhamnus frangula 20 cm. long and 1.5 cm.

thick, after having lain for 4 weeks in water of from 4? to 8? R.

was treated and weighed as follows:—

6 hrs. in water at 20? R. weighed 51.4 gms. Water inside 28.6

“e [11 [11 V v [23 52.5 [11 “ce [23 2097

1 “ Lii “ [11 30° ce 51.4 i & Lii 28.6

y. i “ee “ [21 25° Li 51.7 i ee ii 28.9

1 ii “ce “ [21 409 ii 51.2 i4 i [11 98.4

1 “ce “ce “ce “ee 9o [11 54.1 cc ec [21 31.3

16 “ce [11 íi [11 4? [21 54.2 [21 Iz [13 31.4

1 “ “ ee [11 30? “ec 52.6 ce [2 [11 29.8

9 “ec “ [11 [11 49 i 54.3 “cc i4 “ce 31.5

Although, as seen from weights No. 2 and No. 7 which are at.

nearly the same temperature, there was a progressive increase in

! Du Hamel. Du transport, de la conservation et de la force des bois. Paris,

? Hartig, Th. “Ueber die endosmotischen Eigenschaften der Pflanzen-

hiiute.” Bot. Zeit., vol. 11, p. 313, 1853. :

3? Sachs, J. * Quellungserscheinungen an Hölzern.” Bot. Zeit, vol. 18,

420 THE AMERICAN NATURALIST [Vor. XL

weight independent of the experiment, still the abrupt change

between Nos. 1 and 2, 2 and 3,5 and 6,8 and 9 shows very well the

increase in weight when cooled and a corresponding decrease when

warmed.

Similar results were obtained whether or not the wood was com-

pletely saturated, although all of Sach’s experiments seem to have

been with material rather near the point of saturation.

In the above experiment the weight of the twig dry was 22.8

gms. which subtracted each time gave the figures in the last column

as the amount of water in the twig at each weighing. It will be

seen that between 4° and 30° there was a loss of 1.6 gms. of water

from the 31.4 gms., which would equal a loss of 5.09 gms. for

each 100 gms. of water. Pure water, however, will expand only

1 gm. for every 100 gms. between the above temperatures.’ Con-

sequently water expansion alone will account for only about one

fifth of the water excretion. Similar results were obtained for

several other woods, including Corylus avellana, Abies excelsa,

birch, beech, and oak, except that in the beech and some others

the excretion was as much as seven times greater than the com-

puted water expansion or even more. In many cases bubbles of

air were extruded on warming, and none of the pieces of wood

were saturated. ‘Therefore Sachs concluded that the increased

excretion of water must have been due to the expansion of gas,

and this without doubt is the only true explanation of the pheno-

mena with which he was dealing.

After recording this and several other similar experiments,

Sachs felt warranted in saying that, if a rooted maple tree at a

temperature of 0? R. in all its parts, is cut in two in the middle

and the lower part with the roots is warmed, water will flow from

the cut surface of the stump; and likewise, if the upper part with

the branches is warmed, sap will flow from the other cut surface.

If, on the other hand, the tree is not cut, then a pressure will

arise in the trunk, which, if an incision is made, will result in a

flow of sap out from both sides of the wound at the same time.

Sachs considered that many phenomena were readily explicable

y the assumption of water and air expansion in the wood.

' As given in Johnson's Encyclopedia, I find the expansion of water would

be only 0.425 gms. for each 100 gms. between 4? and 30?; therefore less than

the amount stated here by Sachs.

No. 474] SAP FLOW IN MAPLE 421

Sachs says: “If we assume that a stem and root has reached an

even temperature between 0° and 4° R, and then suddenly a marked

_warming of the air occurs, at first only the crown and the stem are

warmed, the thinnest twigs first of all; a part of their water is

forced back into the thicker twigs, these in turn are warmed and a

portion of their water is forced back into the cold trunk, which

is warmed most slowly. Even this at length becomes warm and

soon water is forced into the root. If now after the roots had

become warm the trunk and top were to become cold through a

sudden fall of temperature in the air, then a flow would occur

from the roots toward the stem and from the stem toward the

branches and so on.” He was not sure whether this was the sole

factor in the sap flow of the maple, birch, ete., in winter.'

But is the gas-expansion theory really capable of accounting

for the pressure observed in the maple tree during the sugar

season? In the Vermont report, a pressure of 24 lbs. (10.8 kg.)

per sq. inch was given in one instance, while pressures of 10 to 15

Ibs. (4.5 to 6.8 kg.) were frequent. The change in external tem- -

perature was in these cases about 5° to 8° C., which would mean

a change of perhaps 3° to 4° within the tree; or, if the sun shone

directly upon the tree, perhaps there would be a rise of from 5°

to 10°, especially in he outer wood and twigs. Gas pressure in-

creases at the rate of for each degree of rise in temperature.

A 6.8 kg. pressure hee pressure per sq. inch) would

therefore equal 6.8 $$ kg. with a rise of one degree. A rise of

from 5 to 10 degrees, as here supposed, would increase the pres-

sure only from 5 kg. to $5 kg., a very small amount com-

pared with the 4.5 to 9 kg. pressure actually obtained. The

Vermont people are justified, therefore, in asserting that gas

expansion cannot possibly account for the pressure observed in the

sugar maple. :

1 For concise statement see his Vorlesungen über Pflanzenphysiologie, p

245 (ed. 2). Sachs failed to distinguish between maple and birch in regard

to the nature of flow. It may be also of interest to note that Sachs’ conclu-

sions were at once sustained by Hofmeister who also brought out additional

evidence to their support (Hofmeister, W., “ Ueber Spannung, Ausflussmenge,

und — ui von Säften lebender Pflanzer," Flora, vol. 45,

p. 97,1

422 THE AMERICAN NATURALIST [Vor. XL

Is the gas-expansion theory capable of accounting for the flow

from the maple? A sap flow as high as 20 liters a day has been

recorded in some instances, but under ordinary conditions the flow

rarely exceeds 10 liters. If we take a tree 5 dm. in diameter and

20 meters high, and assume that the branches if pressed together

in an erect position would approximately complete a cylinder

with a diameter of the lower trunk and a height of the tree, we find

that the volume of the tree would be approximately 3.927 cu. m.

As given by the Vermont Bulletin, about 25% of this volume is

gas or about 981,745 cc. This would expand for every degree

3596.1 cc. For a rise of from 5 to 10 degrees the expansion would

be from 17,980.5 cc. to 35,961.0 cc. If we were justified in assum-

ing the transmission of pressure without friction from all parts.

of the tree then this gas expansion would easily cover the ordinary

10,000 cc. flow, and even the maximum of 20,000 cc. But we

are not justified in such an assumption. Resistance within the

tree is great, and pressure, according to the Vermont studies, is.

not transmitted more than eight feet either way from the tap-hole.

Therefore in such a section of the above trunk 16 ft. long (487.5 cm.)

and hence containing 239,300 cc. of gas, a rise of one degree would

cause an expansion of 876.5 cc. or 8765 cc. for 10 degrees. This

would barely account for the ordinary flow of 10,000 cc. It is

not true, however, that the whole of the water, even in such a

section of the trunk, is in frictionless connection with the tap-hole.

Water travels with great difficulty transversely from one annual

ring to another, so that the outer layers only would probably fur-

nish the main quantity of the sap. In such case the gas expansion

of these layers would probably be only from 1 to 1 ofthe whole

amount for the above section of trunk, and would scarcely account

for even the smaller daily flows.

Moreover, the gas, as shown above, is at this season mostly,

if not entirely, confined in the wood fibers. Gases diffuse through

moistened cell walls only with difficulty so that a heavy pressure

and considerable time would be required before the diffusion could

be of much magnitude. In answer to this objection it might be

claimed that if the wood fiber, instead of containing air alone,

were partly filled with water, as is frequently true, then the ex-

pansion of the gas might press the liquid out with much greater

No. 474] SAP FLOW IN MAPLE 423

ease than it could pass out itself. However, the resistance in any

case would be so great that to conceive of even a fourth of the total

expansion being transmitted to the single small tap-hole is very

difficult. Then, too, if the fibers are nearly filled with gas as

seems true in many cases, early in the Season at least, the expansion

could be but slight before the limits of the cell cavity would be

reached. As there would be no more sap to be forced from the

cell and as the passage of the gas is difficult, the pressure at the

tap-hole would necessarily cease altogether.

The gas-expansion theory cannot account for the pressures

obtained, and can account for the volume of flow only by assuming

very improbable conditions. It seems to be really out of the

question. Sachs’ interpretations were doubtless correct for the

phenomena investigated, but the conditions in the maple tree are

not of the same nature as those in the blocks of wood used in his

experiments.

THE WATER-EXPANSION THEORY

One of the earliest as well as one of the most general of the

beliefs regarding the cause of pressure in maple has referred it to

the expansion of the sap itself as the temperature rose on a good

sap morning. In presenting the facts favorable to such an inter-

pretation it is important to note first that in maple during the

flowing season the vessels are practically full of sap, while the

gas is mostly localized in the wood fibers. It seems fair to sup-

pose that the water can be forced from the vessels into the wood

fibers only with some difficulty. Sachs showed that considerable

pressure was required to force water through wood in a radial

direction, and the Vermont experiments show that little pressure

is transmitted laterally. Therefore if the temperature rises quickly

in the morning the expanding water may be prevented from flowing

at once into the fibers. Now if water is held under confinement

free or nearly so from air bubbles, as is here the case, very slight

expansion could cause a pressure of very great intensity for a short

time. When later the water had penetrated the wood fibers, this

pressure would rapidly fall just as it actually does fall in the maple

tree. The maximum pressure in the maple occurs one hour or one

424 THE AMERICAN NATURALIST [Vor. XL

and one half hours after pressure begins in the morning. From this

time on pressure falls gradually to the zero point. ‘The highest

pressure occurs, therefore, several hours before the time of maxi-

mum air temperature for the day, and the maximum temperature

within the tree would be still later. Still the most abrupt rise is.

no doubt early in the morning when the sunlight first falls upon

the tree, while the subsequent daily rise must be much more

gradual. It might, therefore, be inferred that later in the day the

percolation of sap into the fibers is sufficiently rapid to offset the

expansion after the first abrupt rise.

When the temperature again falls below the freezing point,

water would be drawn back into the vessels from the fibers and

from more distant parts of the tree whither it had been forced.

In many cases, as seen in the Vermont Bulletin, suction is greatest

at first, but gradually decreases if the cold persists for some time.

Suetion during cold nights might be due either to the presence of

a normal two or three pound suction in the tree at this season, or

to the difficulty which the fluid that had passed into the wood

fiber encountered in going back through the walls. When the

temperature remains high, for a long time little pressure occurs

though the fluctuations in temperature may be great. Only a

previously low temperature insures a good run when the mercury

again rises, and it is better if the cold endures for several days.

A cause of this might be that at the high temperature, air creeps

into the vessels from the expanded gas in the various tissues so

that fluctuations are no longer transmitted. During the con-

tinued cold the air would pass back to the older cells thus leaving

once more a solid column of water.

The objection that the sap occupies its least volume at 4 degrees

and therefore at a temperature above that at which pressure begins,

is invalid because only pure water behaves thus. With concentra-

tion of solution this density point falls much more rapidly than the

freezing point, becomes less marked, and soon becomes identical

with the freezing point so that with comparatively slight con- '

centration it would either have disappeared entirely or at least have

fallen to 0? C. when it could no longer be used as an objection.

It is possible, therefore, to explain the extreme pressure and

many fluctuations peculiar to the maple by this theory, but it has

No. 474] SAP FLOW IN MAPLE 425

one very weak point. This is the assumed high impermeability of

the fiber walls. Although it is probably impossible to force water

through many such walls with the pressure observed, still we are

scarcely justified in assuming that one or two walls only separating

the vessels from the adjacent fibers would be so highly impermeable.

This seems improbable.

To determine whether this theory will account for the volume

of flow a few computations must be made. In the Vermont

Bulletin the trunk of a certain tree was computed to contain 1220.5

Ibs. (553,609.6 ce.) of water (p. 62). The coéfficient of expansion

of water between 4° and 8° C. is 0.000,118 for the whole 4 degrees,

which would give an increase in volume of 65.3 cc. for the whole

amount. A rise from 8° to 15° C. with a coéfficient of 0.000,729

would give an additional 403.5 cc. Since tree temperatures vary

only a few degrees the expansion in any case would be only a very

small fraction of the whole flow. For a tree 20 meters high and

5 dm. in diameter, the volume would be 3.927 cu. m., provided

that the branches if pressed together would approximately fill out

the trunk cylinder to the total height of the tree. If a cubic foot

of dry maple wood weighs 43.08 Ibs. the dry tree would weigh

2,709,895 gms., 45% of the tree is water, and 55% is wood; there-

fore, the weight of the water would be 2,217,332 gms. The ex-

pansion from 4° to 8° C. would be 261.7 cc. If it were possible

to believe that the water of the whole tree could flow to the tap-

hole without resistance, the flow would be still only one fourth

to one half of the actual daily flow. Since, however, it has been

shown that pressure is transmitted only about eight feet each way

from the tap-hole, the volume of water which expansion might

cause to flow to the tap-hole would be only a fraction of the whole.

If water passes into the wood fibers to any extent the flow due

to expansion would be still less, only about +4 to # of the whole

ow.

The wood of the majority of trees is structurally so constituted

as to render the passage of water difficult radially from one annual

ring to another, while at the same time there may be fairly good

communication laterally owing to the bordered pits (in the Coni-

fer) and the anastomosis of vessels in the broad-leaf trees. It is

very probable, therefore, that not the whole 16-foot (4.8 meters)

426 THE AMERICAN NATURALIST [Vor. XL

section of the trunk would be tributary to the tap-hole, but only

the few outer layers. If this be true, the flow to be expected from

this source would be an extremely small fraction of the whole

flow, not more than 34 to ṣẹ. It is obvious, therefore, that sap

expansion cannot account for the flow in the maple.

Moreover, it is also not easy to see why air should pass back

into.the wood fibers on cooling below 0° C. at a time when there is

actual suction in the vessels. Even if this were possible the

theory cannot account for the flow, and can account for the pres-

sure only by supposing the walls of the wood fibers impervious to

water to an extent beyond the range of probability. ‘The water-

expansion theory must therefore be considered almost, if not

quite, out of the question.

THE Woop-EXPANSION THEORY

There is still another possible source of pressure due to heat

expansion, namely, the expansion of the wood itself. Wood ex-

pands, as well as swells, more in transverse than in longitudinal

direction. ‘The coéfficient of expansion as determined by Villari *

for dry maple wood is 0.000,006,38 in longitudinal direction, and

‘0.000,048,4 parallel with the radius. The coéfficient for wet wood

is not recorded, but it must be considerably greater.

Let us suppose that the rising sun falls abruptly upon the tree

or that the air temperature itself rises rapidly; then the outer

layer of wood will be warmed much more rapidly than the inner,

and probably the rise will be several degrees in the outermost

layers. ‘These outer layers will tend to expand, but being firmly

united with the inner, such expansion is possible only to the extent

of the elasticity of the wood. The result will be, therefore, a pres-

sure among the elements composing the outer layers. The vessels

of maple wood are quite large and surrounded by fibers. Since

the latter contain the bulk of the wall-substance, they, in expand-

ing, would tend to press upon the large cavities, the vessels. Since

' Villari, L. “Experimental-Untersuchungen über einige Eigenschaften

‚des mit seinen Fasern parallel oder transversal durchschnittenen Holzes.”

Pogg. Ann. d. Physik u. Cheme, vol. 133, p. 400, 1868.

No. 474] SAP FLOW IN MAPLE 427

the walls of the vessels are not so thick as those of the fibers, it is

very likely that the large tubes would become to a slight extent

collapsed. If they were completely filled with sap, the pressure

would be transmitted directly to the pressure gauge. Later in

the day, the temperature having penetrated to the inner layers of

the tree, the pressure would disappear. Such a theory could also

account for the very slight pressure observed in twigs which have

a small diameter and are therefore quickly heated throughout.

Again, from another standpoint, it is known that wood expands

more across grain than longitudinally. Probably, like the swelling

of wood cells, this is dependent upon the micellar structure of the

walls themselves. As in the case of swelling therefore, it may be

that the wood is free to expand tangentially, but is retarded radially

by the massive pith-rays, the cells of which lie upon their side so

to speak, and therefore expand less in the radial direction. The

wood may in this way, independent of the contrast between inner

and outer temperature develop an internal pressure, which would

tend to compress the vessels as in the previous case. Pressure

produced by this method, however, would not tend to disappear

with the penetration of the heat.

As in the water-expansion theory, here, too, the same relation

must be supposed to exist between the wood fibers and the vessels,

and the same impenetrability of the walls must be assumed. . Con-

sequently the objection must again be brought forward to assuming

such a high degree of impermeability. The expansion of wood is

even less than that of water and hence a still higher impermeability

must be assumed. Granted this impermeability, however, an

almost unlimited pressure could be theoretically obtained.

Suction could be accounted for, as in the water-expansion theory,

either by supposing a normal two or three pound suction in the

tree, or by supposing that some fluid had passed into the wood

fibers and was retarded in its return.

The occurrence of maximum pressure so early in the day could

be accounted for under the first method of pressure-origin by

assuming that after a short time the temperature in the outer and

inner layers had equalized to a large extent; and under the other

! Roth, F. “Timber.” U. S. Dept. Agric., Dept. Forestry, bull. 10, p. 32.

428 THE AMERICAN NATURALIST [Vor. XL

method by assuming that after the first abrupt expansion the sap

flowed off through the tissues to the wood fibers, or to more distant

parts of the tree faster than expansion took place.

Let us take the same case cited under the water-expansion

theory of a maple tree 20 meters high and 5 dm. in diameter at the

. base, and a volume approximately 3.926,98 cu. m. as determined

above. The radial coéfficient of expansion for dry maple wood

is 0.000,048,4; if wet it would be greater, suppose 0.000,088,4. In

tangential direction it would probably be greater still owing to the

absence of pith-rays, say 0.000,15 or an average coéfficient of

0.000,119,2. The radius is 0.25 m., and for one degree of rise

it would become 0.250,029,8 m.; the area would be 0.196,396

sq. m., and assuming that the length remains the same, the

volume would be 3.927,92 cu. m., an increase of 940 cc. for

one degree, or 3660 cc. for four degrees. This is only about 3.6

liters to be compared with the actual flow often of 10 or more

liters. Under the most favorable conditions, presupposing the

transmission of pressure from the most distant parts of the tree,

and the equal penetration of heat, the flow would be only a fraction

of the total flow on many days. If the pressure is transmitted

only eight feet each way the flow would be slight indeed, and if

produced only in the outer layers, as it would be necessary to

suppose if we consider the pressure due to contrast between inner

and outer temperatures, the flow would be insignificant.

In order that the pressure should become evident at all from

such a source an almost absolute impermeability of the fiber walls

must be assumed, otherwise the very insignificant amount of

expanded water would in a very short time pass through and

pressure would soon cease. ‘This theory, therefore, fails to account

for the volume of sap flow; and pressure can be accounted for

only by assuming the almost absolute impermeability of the walls

and saturation of the vessels, the former of which at least, is very

improbable.

COMBINATION OF GAS- AND WATER-EXPANSION THEORIES

It has been shown that the expansion of the gas cannot account

for the pressure, and can account for the volume of flow only when

the resistance within the tree is reduced to a point considerably

No. 474] SAP FLOW IN MAPLE 429

below what we should expect. Supposing, however, that it is

able to account for the flow, is there any way of combining this

with the water expansion so that the water expansion will account

for the pressure and the gas expansion for the flow?

Early in the sap season the wood fibers appear filled with gas

while the vessels are nearly or quite saturated with sap. The

sunlight falling upon the tree in the early morning would rather

abruptly warm the outer layers several degrees. Provided now

that the walls of the fibers are slowly permeable to water, as has

already been shown to be the case to some extent, then a high

pressure would be produced by the expansion of the water in the

vessels. Rapid expansion would quickly diminish, however, and

the slow filtration of sap into the wood fibers would at first counter-

balance the remaining expansion, then finally reduce the whole

pressure gradually to nearly zero. Fall in temperature late in the

day would aid this. Since some of the sap has passed into the

wood fibers there would be suction at first at night. This would

gradually decrease as the night progresses owing to the return

filtration from the wood fibers. This theory could therefore

account for the fall in pressure before the maximum temperature

in the outside air is reached. Since the fall of temperature is

always more gradual than the rise, due to the direct rays of the sun,

the suction at night would never be as great as the day pressure,

and it never is. After several days of rapid fluctuation of temper-

ature, or after a period of warm weather, gas might separate in

the vessels thereby rapidly diminishing the pressure to be ob-

tained by equal fluctuations of temperature. This fact would

account for the cessation of flow during a protracted thaw. A

continued period of cold, however, might cause the absorption of

gas and the resaturation of the vessels.

The flow can be accounted for by this theory only by supposing

the wood fibers but partly filled with gas, thus allowing expansion.

The expansion of the gas within the cells as the temperature rises

will gradually force sap out into the vessels. The sap will then

flow from the tree if tapped until the gas expansion is completed.

The objections to this theory are several. It must assume an

impermeability of the wall substance which is beyond probability.

Again, the volume of water produced by expansion is only about

430 THE AMERICAN NATURALIST [Vor. XL

one liter from the whole tree. Since this is distributed over the

whole tree, and the numerous vessels expose an immense surface

to the wood fibers, an almost complete impermeability would be

necessary to affect the pressure markedly. But the gas expansion

must later be supposed to overcome this same resistance. Con-

sidering the weak pressure of the gas and its compressibility it

would be impossible for more than a small fraction of the whole

volume of gas expansion to be transmitted to the tap-hole. ‘The

volume of flow is only barely accounted for by the total gas ex-

pansion, hence under these conditions only a small fraction of

the flow would occur. Again, if gas expansion in the fibers causes

flow, the latter would rise to a maximum slightly after the air

‘temperature. The water expansion in the vessels would tend,

however, to cause maximum flow at maximum pressure. ‘The

actual maximum would be a resultant of the two, so the curve of

flow would reach its maximum later than the pressure curve and

fall much more slowly. This is not the case with curves prepared

from tables in the Vermont report. The curves of pressure and

flow are almost exactly coincident.

It seems evident therefore that this theory also must be laid

aside.

COMBINATION OF WOOD-EXPANSION AND Gas THEORIES

It has been suggested that although the expansion of the wood

is not sufficient to account for the total flow of sap, still, if com-

bined with the gas expansion, the two together might account for

both pressure and flow. Granting that the vessels are nearly if

not quite saturated with water and that the gas is mainly within

the wood fibers, both of which conditions seem to be true, then

when the tree warms, the conditions would be as follows. The

rapid warming of the outer layers of wood when the sun first falls

upon them in the early morning would produce pressure as already

outlined. With the vessels saturated, this pressure might be very

great. As the day progresses the expansion of the wood goes on

more slowly, and as the inner layers become warmed the outer

layers are subjected to constantly decreasing strain. Meanwhile

the sap would be constantly but slowly filtering through the walls

No. 474] SAP FLOW IN MAPLE 431

into the cavities of the wood fibers and thus compressing the gas

there present. This filtration, although too slow to offset all the

pressure early in the day would materially decrease it, and later

overcome it altogether. But the gas has meanwhile become

warmed and tends to force water back into the vessels. If the

tap-hole is open, a flow due to the gas expansion would occur.

Such a flow would be greatest early in the day when the wood

expansion was also acting and gradually decrease but at a much

slower rate than the decrease of pressure, due to the great elasticity

of the gas and to the fact that the maximum volume of the gas

would be at maximum temperature. The retarding effect of the

slow conduction of heat would probably postpone the maximum still

later. If we assume, therefore, that the expansion of gas at these

temperatures is great enough to account for the volume of flow,

then this theory might possibly furnish a means of accounting for

the pressure and flow together.

The objections are several, and fatal to the theory. The most

important objection lies in the probability that gas expansion

cannot account for the flow, as outlined above under the discussion

of that theory. Much less could the gas account for the flow if

considerable force were required to transfer the sap through the

walls of the vessels, as our present theory demands. Again, as

described under the water-expansion theory, we have no good

reason to assume such an almost absolute impermeability of the

cell walls to water. Again, curves plotted from tables XVI and

XVII of the Vermont report show that the sap-flow and pressure

curves are practically parallel. "The maximum pressure and maxi-

mum flow are coincident, and both decrease gradually and equally

as the day advances. The maximum of each occurs usually

within an hour or two after starting, and the fall begins some time

before the maximum temperature of the air, much less of the tree,

is reached. |

This theory also must be laid aside as improbable.

432 THE AMERICAN NATURALIST ` [Vor. XL

THE FREEZING THEORY

Professor Clark ' and others were inclined to believe the pressure

in the maple due to the expansion caused by the freezing of the

water within the tissue. “ T'he sap is separated from the cellulose

of the wood by the cold and under ordinary conditions reabsorbed.

The bleeding is, therefore, a sort of leakage from the wood, but

this is doubtless increased by the elastic forces of the gases in the

tree which are compressed by the liberated sap, and the expansive

power must be intensified by the increase in temperature which

always accompanies a flow.

“ This theory explains the fluctuation of the gauges, and accounts

for the singular fact that the upper one shows the most pressure

and the greatest variations in as much as the branches and twigs

would of course be most quickly and powerfully affected by the

heat of the sun and the temperature of the atmosphere. ‘The pres-

sure of the expanded gases in a tree in a normal condition would

facilitate the reabsorption by the wood of the liberated sap. Their

contraction by cold would also cause the cessation of flow from

a tree which was running, and produce the remarkable phenom-

enon of suction exhibited by the gauges at night or during frosty

weather.”

That the water would be drawn from the walls, our present

knowledge of the freezing process shows to be true. First, the

water in the lumen would congeal, then to these crystals water of

imbibition in the walls would flow. If at the start the vessels are

nearly or quite saturated, then the extra water from the walls, to-

gether with the expansion of the forming ice, would very naturally

cause great pressure. In this wise the walls of the vessels or

other chambers containing ice would be forced apart in proportion

to their elasticity so that on thawing, the water would be under

great pressure until sufficient time had elapsed for it to return

again to the cells and walls from which it came.

It is diffieult to compute the amount of flow that could be

expected from such a source of pressure, but it might be consider-

able depending upon the amount of elastic expansion of the tracheal

1 Clark. Observations on the Phenomena of Plant-life, p. 62.

No. 474] SAP FLOW IN MAPLE 433

walls, and the slowness of the return of water to its original location

in the walls.

The objections to this theory are very serious. Firstly, the

forces of imbibition are sufficiently strong ordinarily to insure a

comparatively rapid return of water to the cell walls. The return

of water to the walls in thawing winter buds I have observed to

take place almost immediately. Flow and pressure throughout

the entire day could not be accounted for in this way. Secondly,

ice does not form in wood at the temperatures obtaining during

the season of flow. A tree temperature of -3° C. was the lowest

obtained by the Vermont Station during this period, while on many

good sap days the tree temperature at night was only -0.5° or

-1° C. The overcooling point, not the true freezing point, is of

importance in determining whether ice will be formed, and this

is always several degrees lower than the freezing point in all

plant tissue. Both are lower than the freezing point of pure water.

Müller-Thurgau ‘ found these temperatures for various sorts of

wood as follows:—

overcool. pt. freez. pt.

Stem of small apple tree ............. eee MC RE apa

One year shoot of pear. .......... ees ee ci e -0.22? C.

One year shoot of pear. ........ orres uc Rd ONE UE -0.25

Old wood OF MAPE 6.50 es seas ce te i5 ee eae -2.85

Young wood of grape ............ eee MD SE -2.1

i Mos Pe PUITS CLER "B: es -3.35

E QE n T E ween bag ee en 2.5

Pir WOOK u. a Se o ene -0.4

The overcooling point seems to be greater in the more dense

woods than in the grape probably because of the large vessels and

watery sap offering little resistance to the inception of ice for-

mation. Maple wood would be of the closer grained type. Ice

formation would probably not commence before a temperature of

-4° to -7° C. was reached. Dixon and Joly? found that ice began

1 Müller-Thurgau. ‘Ueber das Gefrieren und Erfrieren der Pflanzen.”

Landw. Jahrb., vol. 15, p. 492, 1886.

? Dixon and Joly. “The Path of the Transpiration Curren .” Ann, Bot.,

vol. 9, p. 416, 1895.

434 THE AMERICAN NATURALIST [Vor. XL

to form in wood of Taxus at -10° or -11° C. Therefore only

during the coldest nights of the sugar season could ice ever form

in the wood. Some of the aberrations in the readings obtained

by various investigators on very cold nights seem to be due to this

cause, since it is not improbable that if ice actually does form in

the vessels an increase of pressure at night rather than a decrease

may be evident for a time.

Freezing, therefore, plays no important part in the phenomena

under discussion.

THEORY THAT PRESSURE IS DUE TO Activity OF LIVING CELLS

Having exhausted the possibilities in which mere physical force

due to expansion is the main factor, we come now to the theories

in which protoplasm plays the main part.

Pressure cannot be caused by the contraction of the protoplasm

with forcible ejection of the sap because of the fragile nature of

the ectoplasm. Even if this were sufficiently strong no pressure

could be obtained unless the exit from the contracting sack was

into a reservoir unconnected with the space around the remaining

surface of the sack. Otherwise the extruded sap would simply

occupy the space left by the contracting protoplasm, and no in-

crease in volume would take place. The alternative then, is for

the pressure to be caused by osmotic phenomena. Pressure and

flow if accounted for in this way must presuppose an exudation,

under pressure, of sap from the living cells.

Exudation is known to occur in Mucor as described by Pfeffer.

In Spirogyra at very low temperatures near zero C., water has been

observed to appear in droplets upon the surface of the cells.'

Drops of water are secreted from the cells of the pulvinus in

Mimosa when stimulated, and from the sensitive staminal filament

of the Cynarem. At present bleeding pressures in root and stem

tissues can be accounted for in no other way. The phenomenon

* Pfeffer. Pflanzenphysiologie, e

Greeley, A. W. “On the between the Effects of Loss of Water

and Lowering of Temperature." Amer. Journ. Physiol., vol. 6, p. 122, 1901.

Livingston, B. E. The Role of Diffusion and Osmotic M in Plants.

Chicago, 1903.

No. 474] SAP FLOW IN MAPLE 435

is, therefore, one known to occur in plant tissues and is apparently

much more widespread than was formerly supposed. Research

is tending to show that bleeding occurs among cells of widely

different tissues, and is probably to be considered a normal and

very general phenomenon in plants.'

The exudation can be conceived to be produced in either of two-

ways: either by change in permeability of the diffusion membrane

allowing water to pass with less friction, or by a change in osmotic

tension. In regard to the first method it may be said that although

diffusion membranes are considered to be freely permeable to water

they really are not quite so. A force is required to press water

through such a membrane as is shown by the fact that a bladder

may be filled with water and suspended in air without the water

escaping immediately. It is conceivable, therefore, that a portion

of the cell membrane might become quite freely permeable to the:

solvent while the remainder continued dense. But so far as we

know the resistance to the passage of water is very slight and plays.

no great part in the determination of pressure in osmotically

active cells. So far as our knowledge goes, osmotic pressures are-

the same, no matter what membranes are used, providing that the

solute is of the same nature and density, and that the membrane is

permeable to it in the same degree, and also permeable to water.

The osmotic pressure of water has been demonstrated in con-

nection with some artificial membranes, but was always found to

be slight. So far as we know at present all pressures of any

moment in connection with semipermeable membranes are pro-

duced directly or indirectly by the action of the solute, and are

proportional to the quantity of the latter present.

We have remaining the alternative of a change in osmotic ten-

sion. But such an alteration in osmotic tension is not sufficient

in itself. Water might be excreted from the cells by a simple

change in permeability of this sort, but the production of pressure-

in the surrounding tissue would be impossible, for as the water

passed out from the cell, the latter would decrease a like amount

in volume and no pressure would ensue, simply a change of location

1 Wieler, A. “Das Bluten der Pflanzen.” Cohn’s Beiträge, vol. 6, p. 1, 1892.

See also Pfeffer, Pflanzenphysiologie.

436 THE AMERICAN NATURALIST [Vor. XL

of the water with reference to the membrane of the cell. To ob-

tain pressure externally by osmotic action it is necessary to assume

a flow of water through the cell. But if the two reservoirs of supply

and excretion are confluent then there will be a flow through the

cell, in at one point and out at another and back again outside to

the starting point, thus forming a circle of flow; and there would

be no external pressure. The reservoir of supply to the cell must

be distinct from the reservoir of excretion. Pressure will then be

produced in the latter reservoir while at the same time, in the

former a tendency toward suction will occur.

Flow through a cell will occur as Pfeffer ' has already shown

(a) if the solute passes through the membrane more easily at one

end than at the other. Osmotic tension will here be less and the

water will be forced out by the tendency to greater pressure at the

other end. Flow will be in at the side of less permeability and out

at that of greater permeability. Such a condition has been

demonstrated experimentally in an artificial cell by Copeland.*

Or (b) a flow will occur if the solute is more concentrated at one

end of the cell. Water would enter in this case at the region of

greatest concentration (greatest osmotic pressure), and pass out

at the region of least concentration; and would continue to flow

as long as the solute remained thus distributed. The difficulty

in this case would lie in the maintenance of unequal concentration

of the solute within the same cell. Since diffusion would soon

equalize any such irregularity it could be accomplished only by

the constant production of more solute at a certain point.

If pressure is due to the unequal permeability of the membrane

to solute then there must always be a secretion of solute along with

the sap into the chamber showing the increased pressure. Sap in

this reservoir cannot be pure water, or even nearly pure water,

unless the plant possesses some means of ridding the sap of such

solute after its excretion either by its immediate change to solid

form or its use in metabolism. In case pressure is due to an

unequal distribution of solute within the cell then no excretion

1 Pfeffer. Pflanzenphysiologie, ed

? Copeland, E. B. «Physiological nd II, an Artificial Endodermis Cell."

Bot. Gaz., vol. 29, p. 437, 1900.

No. 474] SAP FLOW IN MAPLE 437

of the solute into the receiving reservoir would necessarily occur.

The exuded sap, in such cases, might be pure water.

That the production of comparatively great pressure is possible

in either of these ways is apparent. As shown by Pfeffer’s table

(p. 146) a difference of one percent in concentration of sugar

solution is equal to a pressure of about 0.69 atmospheres or 10.3

Ibs. (4.6 kg.). Twenty pounds pressure, which is about the

maximum for the maple, would be equivalent to a difference of

2% in concentration. This is not too great to expect considering

that the percent of sugar in maple sap is from 1 to 5.5 and that

local concentration might be much greater for a short time before

diffusion. One might reasonably expect a higher pressure.

It is very difficult to bring forward any general theoretical

evidence to establish the impossibility of either the excretion of *

solute theory, or the unequal distribution theory. But the fact

that sugar actually passes into the vessels in large quantities lends

a probability almost convincing to the idea that the increased

permeability allowing the sugar to escape is also the cause of the

pressure.

Maple wood is diffuse-porous, the vessels being scattered

rather evenly throughout the annual ring, although they are per-

haps slightly more numerous in the spring wood. The vessels

are large, solitary, or, more usually, two or three together and

surrounded by the moderately thick-walled wood fibers. These

latter form the main bulk of the woody portion. Wood paren-

chyma is very scarce, and is confined to a few rows of cells in the

vicinity of the vessels at points where they are adjacent to the

pith rays. There is some question whether this tissue is wood

parenchyma since there are no cross walls as ordinarily; or whether

the cells are not wood fibers like the rest but with cellulose walls.

I am inclined toward the latter view since the similarity is other-

wise so striking. The wood fibers are without markings but the

vessels are densely pitted. Pith rays are numerous in maple and

very large (Fig. 1). An estimate seems to show that they occupy

about one fourth of the volume of the wood. ‘The larger ones are

from 8 to 10 cells high and from 3 to 4 cells thick, ellipsoidal in

tangential section, and extend from the cortex to varying depths

into the wood, some reaching to the center. The cells of the pith

438 THE AMERICAN NATURALIST [Vor. XL

rays are slightly smaller in diameter than are the wood fibers, and

the walls are thick and lignified. In radial direction they are from

3 to 5 times as long as wide. Through the various walls pits

extend. These are sparse on the side walls adjacent to the

wood fibers, and are simply very narrow canals extending at least

part way through the wall. I was not able to demonstrate that

Fic. 1.— Maple wood, tangential section, Note the massive pith rays, and the

large number of wood fibers,

they passed entirely through. At any rate the communication

laterally through the walls must be slight, and passage difficult.

Similar narrow pits, though somewhat larger, are very abundant

on the end walls, and, except possibly for a closing membrane, are

very obviously continuous from one cell to another (Fig. 2).

No. 474] SAP FLOW IN MAPLE 439

When the pith rays are contiguous to a vessel, large bordered pits

are abundant in the common wall between them. Elsewhere on

the vessels, pits seem to be absent, except in the walls between the

few wood parenchyma cells and the vessels. Preparations stained

with hematoxylin showed purple in the wood only where pith

Fic. — ray of maple in radial view stained with iodine. The cavities of

e four dark cells are filled with gas. This causes the pits to become

ra plainly visible, The dark bodies in the other cells are starch grains,

rays, or the sparse wood parenchyma touched the vessels. It

seems probable therefore, that all the walls are lignified except

just at these regions that stain, and these probably remain cellulose.

On March 25th, sections stained with iodine after the heematoxy-

lin showed the pith rays well filled with starch. Starch was also

present in abundance in the wood parenchyma cells about the

440 THE AMERICAN NATURALIST [Vor. XL

vessels, and in some of the wood fibers. The starch-containing

fibers were mostly either adjacent to the vessels or clustered in a

band at the end of each year's growth. The other wood fibers

contained none at all. All of these cells with starch are living

and contain protoplasm. In autumn we find the starch-con-

taining cells of the maple packed full of this substance as in other

trees. From the time cold weather commences until spring,

starch is gradually converted into sugar. Fischer’ has found

this to be the case in many trees. 'The Vermont workers also

found the starch content to decrease in early spring, and the

sugar-content to increase. There is, however, no evidence to

show that sugar is again reconverted into starch in late spring as

Fischer states to be the case in some trees. It seems that the

starch stored in the pith-ray cells and in the wood fibers described

above is gradually converted into sugar as spring advances. Since

there is no other source for the constantly increasing sugar content

of the sap in the vessels it seems reasonably certain that this sugar

escapes into the vessels from the starch cells where it is formed.

If pressure and flow are due to the living cells they must then

be due to the pith-ray system, the wood-fiber system, or both, since

these constitute the living part of the wood. In wood, as shown

by Sachs, the only direction in which water passes with difficulty

is radially. In longitudinal and tangential directions there is.

little obstruction to the flow. Moreover, although in the previous

discussions in this paper, the fiber walls were hypothetically con-

sidered as almost impermeable to water, it seems more likely

that one or even two walls intervening would retard the passage

of water but little. At any rate, it is scarcely probable that a

strand of starch-containing wood fibers contiguous to a vessel at

one end would be more than two or three walls distant at the other

end, and therefore there would be no way of obtaining for such a.

strand the two distinct water reservoirs necessary for the pro-

duction of pressure.

In order that a homogeneous membrane should become suddenly

more permeable at certain regions at a definite rising temperature

1 Fischer, A. “Beiträge zur Physiologie der Holzgewüchse." Pringsh.

Jahrb., vol. 22, p. 73, 1891.

No. 474] SAP FLOW IN MAPLE 441

only, it seems reasonable that some stimulus must be applied, and

since other factors are practically constant, it seems reasonable to

expect this stimulus to be the rising temperature. It is difficult

to think of any other factor among the conditions obtaining in a

bleeding maple tree that could give such a stimulus. But the

temperature changes would reach all parts of a narrow longitudinal

wood fiber at almost the same time, and the stimulus would not in

that case be unequal. For these reasons it seems improbable

that the wood fibers can take any great part in the production of

pressure and flow.

This is not the case, however, with the pith rays. Extending

radially through the wood with few lateral pits and numerous

end ones, they are admirably adapted for radial conduction with-

out much lateral loss. Only at comparatively long intervals where

they touch a vessel are they connected with the surrounding wood.

The radial conduction of water in any wood is very limited, and

the many layers of wood fibers in this case would form an especially

efficient barrier between the inner and outer wood, each layer of

which could here serve as one reservoir of the system. If we

suppose the ray cells more permeable to sugar at the outer or the

inner ends, then conditions are all suitable for the production of

pressure and flow. The penetration of early morning heat would

tend to warm all of the radially elongated ray cells at the outer end

before the inner. ‘Throughout the whole period of rising tem-

perature therefore one end of each cell would be slightly warmer

than the other. It is easy to conceive of this condition acting as

a stimulus to cause a similar unequal permeability in all the cells.

We may conceive of the phenomenon occurring somewhat in

this way. During the winter months but little starch is converted

into sugar. As spring approaches, and up to the time of vernation,

the stored starch is gradually converted. In this way the sap of

the living cell must become highly concentrated and the osmotic

force very great. During constant temperature, however, the pro-

toplasmic membranes are either almost equally permeable to sugar

over all parts of their surface, or not permeable at all. The latter

is not probable since the concentration within the cell would soon

become very great.

Rising temperature, however, by warming the peripheral ends

442 THE AMERICAN NATURALIST [Vor. XL

of the cells first, acts as a stimulus and causes the ray cells to be-

come more permeable to sugar at one end, which is the same end

in every case. Since the greater pressure and sugar content is in

the outer wood, it seems probable that the outer ends of the ray

cells rather than the inner become more permeable, and the flow

would be therefore from the heart wood toward the cortex. In an

untapped tree of course there would be scarcely any flow, simply

statical pressure, but sugar would pass into the vessels just the

same. But the mechanism cannot be quite as simple as it seems

ee 7 Hu o y c

A 5 15 5 15 5

I a II a II a

= Pin Bark —

y tc I t

Dif. Dif.

B 545 515 10 515 55 w 5115

I a u a" Hi a"

Dif. Dif. Dif.

C 15 10 515 10 5115 10 515

I II m

Fig. 3.— Diagrams representing chains of pith-ray cells, I, II, III, cell cavities;

a, cell wall separating membranes z and y. Tendency to 15 gm. pressure

at one end of the cell and 5 gm. at the other.

at first. It will not do to assume simply that the membrane at

one end of the cell becomes more permeable to the solute in both

directions than does that at the other end. Let A and B in Fig.

3 each represent three pith-ray cells, and the intervening shaded

portions the cell walls between. Suppose that in A, at the x

membranes of each cell, there is a tendency * to 15 gm. osmotic

pressure, while at the y membranes there is a tendency to only

1 The word tendency is here used erae in all parts of a liquid the hydro-

static pressure must mn be the sam

No. 474] SAP FLOW IN MAPLE 443

5 gms. Sufficient sugar is passing out through the ; membranes

to equal the difference of 10 gms. pressure. The sugar now in

chamber a would tend to exert a pressure of 15 gms. toward

membrane x and a pressure of 10 gms. against membrane y, which

would cause a reverse pressure of 10 gms. offsetting the pressure

caused by the cell. Only if the solute could be carried away as

soon as excreted could this mechanism work to produce pressure,

but the assumption of such freedom for the solute would neces-

sitate a still greater freedom for the solvent, which would make

the existence of two unconnected reservoirs impossible. It is

obvious therefore that no pressure can be produced by this method.

In order to obtain pressure it is necessary to assume unequal

permeability of the membrane in the two directions. In B we

may suppose each end membrane to show a tendency to 5 gm.

pressure on its left-hand. side and 15 gms. pressure on its right.

Then water would pass from the cell to chamber a under 10 gms.

pressure, and from this chamber to the next cell under 10 gms.

again, and so on. This arrangement would also account for the

passage of sugar from one cell to another, which could not be

explained by the first method.

If, as there seems some reason to believe, the two membranes

on either side of the cell wall act as one owing to the numerous

plasma connections between them, then, as may be seen from C,

(Fig. 3), the assumption of unequal permeability of the same

membrane in opposite directions is the only one that will account

for the phenomenon. It seems, therefore, that in any case we must

assume not simply that the membrane at one end of the cell is

more permeable than that at the other, but that each end membrane

is more permeable in the direction toward the bark than toward

the pith.

I see no reason why the pressure produced by the various cells

should not be accumulative, that is, if we have three cells each

producing a 10 gms. pressure we might expect a pressure of 30

gms. at the end of the series, or perhaps even double that if it is

assumed that the cell wall forms a distinet chamber. For example,

in B (Fig. 3) sap from cell I is forced into chamber a under 10 gms.

pressure. Chamber a forces sap into cell II under a pressure of

10 gms. also; but, disregarding friction, cell I would have forced

444 THE AMERICAN NATURALIST [Vor. XL

water through the cavity a into cell II with 10 gms. pressure if

a had contained only pure water. Is it not reasonable then that

sap would be actually forced into cell II under 10 + 10 gms.

pressure, and so on? If this is true then it would seem that the

longer the pith ray the greater would be the peripheral pressure.

Large trees would be expected to show more pressure than small

ones. Unfortunately, records of pressure in trees of various sizes

have not yet been made.

But it is not necessary or even probable that this is the case.

The temperature each morning penetrates the wood in a wave-

like manner. Only a few cells in each pith ray would be subject

to the critical temperature at the same time; those farther within

would be yet unstimulated, while those farther out would be

recovering from the stimulation. Therefore but few cells would

actually take part in the production of pressure at any one time.

. If this is true, the size of the tree would have little effect upon the

pressure, within certain limits. I am inclined to suspect, how-

ever, that the diminished pressure in the branches and twigs may

be, in the main, owing to this.

The question naturally arises why, if conditions are as here

outlined, a pressure of 9 kg. in the outer wood would not necessarily

be accompanied by a suction of 9 kg. in the inner wood, or indeed

by 9 kg. plus the natural suction of the tree; but no such suction

as this has been recorded. It may be mentioned that there seem

to be no recorded accounts of search for pressure or suction at a

greater depth than 10 to 13 cm. But the question may be con-

sidered from another standpoint. As stated above, the production

of pressure would probably be confined to a comparatively few

cells in each series. When pressure begins in the morning the

active zone is near the bark, and water would be forced into a

comparatively limited chamber, the contained gas would be

rapidly compressed, and great pressure would be produced; but

the water would be drawn from all the other layers of the trunk.

The gas of all these layers would be expanded only a very slight

amount, and little extra suction would be produced. Incidentally,

the high pressures have all been recorded in the outer wood soon

after flow. began in the morning.

The rising temperature probably does not act as a constantly

No. 474] SAP FLOW IN MAPLE 445

increasing stimulus, but as an abrupt one. As the critical temper-

ature is reached the mechanism of stimulation is perhaps set off

all at once, so to speak, and the maximum permeability is reached

very soon, and consequently the maximum pressure and flow. As

the day progresses either the already converted sugar in the cell

is exhausted or the membrane gradually recovers its normal con-

dition as it recovers from the stimulus. It seems more likely

that the recovery is not due to the exhaustion of sugar content

because on succeeding warm days without freezing nights there

is still evident considerable fluctuation with temperature showing

that some sugar is still there. Then again, if the membrane

remained unequally permeable, the small amount of sugar con-

version that does constantly occur would tend to maintain a

constant though slight pressure until by a fall to 0° C. the mem-

brane became again equally permeable; but instead suction usually

soon occurs. It seems much more reasonable that after the abrupt

stimulation the protoplasm should soon gradually recover its

original condition. The slight fluctuation in pressure that occurs

each morning even during a thaw period is probably due either

to a recurring but slighter degree of difference in permeability,

or to an abrupt increase in sugar production induced by the rising

temperature. Since abrupt fluctuation in sugar production suf-

ficient to cause pressure is improbable, the former hypothesis

seems the more reasonable.

There is no reason to believe the conversion of sugar to be

otherwise than normal, that is, gradual and constantly progressive,

less rapid when the temperature is low and more rapid when higher

according to the normal action of enzymes. I see no reason to

assume that at 0° C. enzyme activity is abruptly stimulated, thereby

converting a large quantity of starch into sugar abruptly at one

end of the cell, and thus causing pressure through the unequal

distribution of the solute. It seems to me more probable that at

a low temperature the membrane is comparatively and almost

uniformly impermeable over its entire surface. Osmotic pressure

is therefore high and the cells are very turgid. A rise of temper-

ature to the critical point now causes the abrupt stimulating shock,

sugar passes out at the peripheral ends of the cells, and both

pressure and flow become great toward the outer wood. After

446 THE AMERICAN NATURALIST [Vor. XL

the first shock the cell begins to recover until the permeability is

again equalized and pressure and flow cease. When the perme-

ability is equalized at a high temperature, as well as at a low one,

suction ensues. Hence the suction so often observed during the

latter part of the thaw period. This suction may be partly due

to the pressure having expelled part of the sap from the outer

layers down toward the root or up toward the branches. ‘Then

after the restoration of equal permeability the tendency to equalize

with the suction of the inner wood would tend to cause some

suction in the outer trunk. The suction during cold nights may

be partly due to the inner ends of the pith-ray cells being warmer

than the outer thereby causing unequal permeability and con-

sequent pressure in the reverse direction. But I believe that the

wood of maple is normally under suction at this period, as is that

of so many other trees, and that the return to suction either at a

high or low temperature is merely a return to the normal. ‘There

is probably always some increase in permeability whenever one

end of the cell is warmer than the other, hence pressure does not

drop to zero until after the temperature has become equalized

throughout the trunk each day; and on succeeding days, even if

there has been no frost, the morning rise of temperature causes

some pressure because of the same unequal warming. It seems

reasonable to suppose that some sugar passes into the vessels at

all times during the period of starch conversion, otherwise the

concentration in the cells would become very great. ‘The passage

is probably less at low temperatures and greater at high temper-

atures. ‘The warmer end of the cell is therefore always the one

toward which flow is directed. Maple probably differs from other

trees having starch stored in the pith rays mainly in (a) the sen-

sitiveness to temperature causing marked unequal permeability at

the two ends of the cell and (b) the spasmodic effect of this stimulus

when the temperature is rising past a certain critical point.

The protoplasm of all sugar maple trees is probably not equally

sensitive. For instance, for a number of years I have observed

a tree which flowed comparatively little sap although this was

unusually sweet, flowed less vigorously on a good sap morning

than most trees, and continued flowing after the other trees had

ceased during a warm spell. I suspect that here the protoplasm

No. 474] SAP FLOW IN MAPLE 447

was simply less responsive and less sensitive, less influenced by

the rise in temperature, and much slower to recover after stimula-

tion. In this way probably much of the observed individuality

existing between different maple trees may be accounted for.

The quantity of sugar in the sap of any tree would be no in-

dication of the difference in permeability, that is of pressure.

This sugar content depends upon the total quantity of starch

stored in the pith rays and the rapidity of conversion as well as on

the permeability. The relatively greater quantity in the sap of

the outer wood over that from the inner layers, on the other hand,

would probably be proportional to the amount of pressure and

flow.

The flow is not always as great as the pressure would lead one

to expect. This may be because in these cases the available

supply of water in the wood is less than usual.

Since each annual cylinder of wood with its system of vessels

is in the form of a cone each extending higher on the tree than the

preceding, water would probably tend to pass from the shorter

layers to the higher ones, thus helping to raise the water in the

tree. Water for the inner layers would probably be drawn prim-

arily from the soil. Pressure in the twigs and branches is usually

much less than in the lower trunk. This may be for three reasons,

viz.,— because the temperature would equalize so quickly, because

the radial chains of pith-ray cells would be shorter than in the

trunk, or because of a less unequal permeability in the cells of the

twigs. When a small branch or twig is cut off, sap flows from

both surfaces but under no great pressure. I believe that the

main portion of the flow in severed branches is due to the com-

pressed air caused by the forcing up of sap into this part of the

branch from the wood below.

Sugar probably passes from the wood fibers from the longitu-

dinal faces if unequal temperature affects them in a similar manner,

and owing to the narrow diameter of the fibers the flow thus caused

would probably return again to the other side of the fibers with-

out causing much, if any, pressure.

An objection to this theory which quickly comes to one’s mind

is the following. Why should the excreted sap pass through the

pits into the next cell rather than around back between the plasma

448 THE AMERICAN NATURALIST [Vor. XL

membrane and the cell wall to the other end of the cell, thus pro-

ducing a flow back through the cell without evident pressure?

This seems impossible to answer at the present state of our knowl-

edge, but it must be remembered that all theories of pressure pro-

duced by unequal permeability must meet this same objection. I

believe, however, that a more critical study of the cell will event-

ually settle this point.

Regarding the water in the inner and outer layers, the Vermont

Bulletin gives determinations up to a depth of 15 em. only, and

these are the only ones available. It was found on December

13th that the water content of the outer wood was considerably

greater than the inner (37.5% and 24%). From that time until

March 11th the percent in the outer layers decreased to 33.4 %

while that of the inner wood increased to 39.1%, thus giving a

greater percentage for the inner layers. From then until April

28th there was an increase in both layers, but principally in the

inner. At about this time the buds began to open and the water

content of both fell abruptly. Along toward the first of June

the content of the outer layers again became greater than the inner

for a few weeks. These results seemed at first to present an

objection to the present theory in that one would expect a greater

water content in the outer layers into which the water would be

forced from the deeper wood by the pumping action of the pith

rays. After further thought, however, I am inclined to believe

that the above readings are to be expected. The outer layers are

subjected alternately to much greater pressures and suctions,

while farther within the fluctuations are moderate, with pre-

dominating suction. It is reasonable to suppose that such violent

fluctuations would gradually cause the accumulation of gas in

these outer layers, and especially since these are near the exterior.

hy this particular temperature of from 1? to 3? C. should be so

efficient in causing abrupt stimulation rather than any other is

also an unsolved question. It must be noted, however, that

several other phenomena seem to be connected more or less

definitely with the same temperature, namely the exudation of

water from the surface of Spirogyra threads already mentioned,

and the gradual death of Coleus and other tender plants when

subjected to this temperature but not frozen. This being the

No. 474] SAP FLOW IN MAPLE 449

temperature at which pure water is at its greatest density suggests

that a re-arrangement of molecules in the water might be the source

of the stimulus. The objection to this is that only pure water

has this point of maximum density while in solutions of but slight

concentration the point rapidly approaches the freezing point,

and soon these two are identical.

It must be borne in mind that the idea that pressure is due to

unequal permeability as above outlined is theory, not demon-

strated fact. Its usefulness should lie in directing future in-

vestigation.

TREES THAT BLEED LATE IN SPRING

Trees of this second group show quite a different behavior in

regard to the environmental factors, especially temperature. In

general the seasonal flow steadily increases from its inception

until the maximum is reached and then as gradually declines. The

composition of the sap of the different species differs according

to the date of flow, and especially the time of beginning. There

is little similarity in the composition of the sap in the different

species. ‘That of birch contains a large percent (6%) of sugar,

but this is glucose, not cane sugar, while that of the grape is almost

pure water and contains no sugar. If trees of this class are cut

down, the stump surface will continue to bleed, in the birch and

grape very freely, while the cut surface of the trunk will soon

become dry.

According to Clark, the black birch begins to bleed about

April 1, attains its maximum the last of April, and stops about

the middle of May. The wild grape commences about May 1st,

arrives at its maximum of flow and pressure about May 30th, and

ceases early in June. ‘The pressure and flow in both of these plants

fluctuates very little as compared with the maple, and depends

very little on the temperature of the air. Great changes in tem-

perature affect the pressure slightly, but only after several hours.

Nearly the whole fluctuation consists in a regular diurnal periodi-

city greatest at night and less in the morning. In this group

of trees the phenomenon is without doubt one of root pressure,

and the fluctuations are characteristic root pressure fluctuations.

450 : THE AMERICAN NATURALIST [Vor. XL

According to Clark, holes bored at different heights in a birch tree

showed that the column of sap was supported almost entirely by

the pressure from the root at the base.

The difference between the bleeding phenomena of the group

of trees which bleed in late spring, and then mainly from the root,

and the trees of the maple type is, after all, perhaps mainly one of

degree only. Although in early spring there is no bleeding from

the root but rather suction in the maple, later in April when the

leaves are about to appear, root activity is evident here also, though

always moderate. Eliminating the peculiar earlier stem pressure

the condition in the maple would be normal for the other group.

In the case of young maple saplings the root activity begins con-

siderably earlier than in large trees, probably due to the shallower

root system. This also happens in the roots of young birch sap-

lings. In the case of these young maple saplings I am inclined

to believe that the flow was perhaps entirely due to root pressure.

On the other hand, the conversion of starch in the trunk and

branch cells of the birch tree may take place at a later date than

in the maple and without the accompanying spasmodic changes

in the permeability of the membranes. Conversion seems to

commence in the root in this case and progress upward, but this

point has not been definitely proven. It seems more natural to

expect the starch of the trunk in these trees as well as in the maple

to be converted before that in the roots owing to the retarding

effect of the slowly warming soil. Whether the trunk tissues of

birch take part in producing pressure late in the season has not

been carefully investigated. From the experiments of Clark it

seems rather doubtful. As we have already learned, pressure is

not a necessary accompaniment of the escape of sugar from living

cells into the vessels.

If we accept the cell-activity theory for the sap flow in the maple

as the most probable, then it seems likely that the difference

between the trunk cells of birch and the other trees of this group

and those of the maple lies in the inability of the temperature or

any other stimulus to cause unequal permeability of the proper

nature (7. e., with the proper mechanism) to cause pressure.

Therefore the only pressure evident in the birch is the so called

root pressure.

No. 474] SAP FLOW IN MAPLE 451

Owing to the difference in structure between roots and stems.

the exact mechanism having to do with the root exudation pheno-

mena in all these trees is a different problem, and not to be dis-

cussed here. |

Molisch ' has recently come to the conclusion that many cases.

of bleeding in trees through tap-holes or other wounds are local,

and exist only after the incision is made. ‘The wound here acts

as a stimulus starting repair phenomena, with increased turgidity

of the neighboring cells. He is inclined to believe, however, that

the spring flows in maple, birch, and grape are general phenomena.

and of another category. To me it also seems that the conditions

outlined at the beginning of this paper rather preclude the con-

sideration of the maple phenomena as local. But I cannot see

that the fact that they were local would in any way preclude the

action of the pith rays as here outlined.

SUMMARY

l. The source of pressure for the bleeding of trees in spring

seems to be localized in different portions of the plant in different

species.

2. Trees may be roughly classified into two groups in this re-

gard: (a) those in which the source is mainly in the trunk and

branches. These, as for example the maple, bleed early in the

season. (b) Those in which the source is in the root only. These

bleed later in the spring, as for example the birch and grape.

3. Only the problem of the cause of pressure in the maple is

considered in this paper.

4. There seems to be an undoubted relation between the oc-

currence of pressure in the maple and the fluctuations in temper-

ature.

5. In connection with no other fluctuating factor of the en-

vironment can such relation be shown.

6. Pressure exists only when the temperature is rising. When

it falls or remains constant, suction occurs.

! Molisch, H. “Ueber localen Blutungsdruck und seine Ursachen." Bot.

Zeit., vol. 60, p. 45, 1902.

452 THE AMERICAN NATURALIST [Vor. XL

7. Except when the temperature is rising past the vieinity of

0° C. the pressure is very moderate or slight. In the latter case,

however, it may rise to the height of from 6 to 9 kg. per sq. in.

in less than one and one half hours. Pressure then begins to fall

whether or not the temperature still continues to rise.

8. The flow is in a general way coincident with, and propor-

tional to, the pressure.

9. Expansion of gas in the wood can by no means account for

the amount of pressure exhibited by the maple; and such ex-

pansion is likewise probably incapable of accounting for the total

amount of flow.

10. Water expansion in the wood, while it can readily account

for the pressure, if confined, is probably not so closely confined,

and at any rate isincapable of accounting for the volume of flow.

11. The expansion of the wood can account for the pressure

only when the sap is confined, and such complete confinement is

highly improbable. It cannot account for the volume of flow.

12. No combination of these theories can produce a sufficient

explanation of both pressure and flow.

13. Freezing is not capable of accounting for the phenomenon.

14. The only theory so far advanced that can account for all

the observed phenomena is the living-cell theory. This seems in

most respects satisfactory.

15. Living cells could produce pressure by contraction only

when the outlet of the cell is unconnected with the chamber imme-

diately around the contracting membrane. The structure of the

cell renders this improbable, and besides, the delicacy of the proto-

plasmic membrane precludes the formation of such high pressures

by this means.

16. Osmotic phenomena seem the only resource. Only by

flow through the cell from one reservoir to another, due to the un-

equal osmotic permeability at the two ends, does it seem possible

to obtain pressure by this method. Osmosis in this way seems

sufficient to account for even more than 9 kg. pressure.

17. The pith-ray cells seem the only ones in the wood in posi-

tion to fulfil the above requirements.

18. The most probable explanation at present is that the pith-

ray cells, stimulated by the rising temperature, become unequally

No. 474] SAP FLOW IN MAPLE 453

permeable thus setting up a current and accompanying pressure

from the pith toward the bark.

19. The maple type seems to differ from the birch type prin-

cipally in the localization of the active cells mainly in the trunk,

rather than in the root; and in the spasmodic action of these under

certain stimulation.

20. It is quite possible that careful research will show no such

irritability in the butternut and other trees of this group as is found

in the maple.

NOTES AND LITERATURE

TEACHING

McMurry’s Special Method in Elementary Science! is by far the

most comprehensive treatment of the subject which has appeared in

this country, and must prove extremely useful to the teacher in the

publie schools. The first half of the book treats of the aims and

method of the teaching of elementary science,— the author at first

makes a brave attempt to call it nature study, but throughout the

greater part of the book calls it science,— the second half offers

model lessons and a very full list of topies for a graded course of study.

Mr. MeMurry insists that the topics shall come from the pupil’s

close environment,— Professor Hodge has already suggested that a

louse on a pupil’s head might be used for an instructive lesson on

vermin,— and he has introduced as a new feature many topics dealing

with the application of science to life. A study of the principles which

govern the great inventions as well as our homely household appliances,

can be made to appeal strongly to children. The author insists that

a generation trained in the elementary problems of sanitation, physi-

- ology, and hygiene will not fall such an easy prey to the patent medicine

frauds, and will back up boards of health in the fight for pure food

and clean streets.

Professor Jackman some time ago outlined a course of nature study

in which topics from every field of physics, chemistry, astronomy,

meteorology, physiography, and biology were coördinated.

MeMurry extends the field still further, so that the variety of EEE

to be handled would, we should think, appal any but the most unusu-

ally well trained teacher. It is a pity that the importance of the

right method does not stand out more clearly. Many teachers will

continue to convey information in many fields instead of

powers of reasoning in one. Mr. McMurry of course insists on the

well known truths which should govern methods in science teaching,

and often expresses his truths forcibly, but this book like all his

! McMurry, Charles A. Special Method in Elementary Science for the Com-

School. New York, The Macmillan Co., 1905. 12 mo, ix + 275 pp.

455

456 THE AMERICAN NATURALIST [Vor. XL.

others suffers from an astonishing obscurity of style and unskilful

presentation. The trail of the German “Pedagogik” is over it all.

In the chapter on method the place of imagination in science

teaching is discussed; “children, primary teachers and poets" are

encouraged to use a certain amount of license. It is amusing in view

of recent controversies to see Mr. Burroughs figure as an example of

the imaginative school of nature students.

There is a en full list of books which serve as an aid in science

teaching.

RH,

EVOLUTION

Lotsy’s Theories of Descent.'— This book is a series of twenty-one

lectures delivered to students at the University of Leyden and designed

“to awaken a desire for the investigation of questions relating to

theories of descent.” This aim it is well adapted to fulfil. The

scope of the book is wide, and the discussions, while necessarily not

exhaustive, never fail to be stimulating and to give the reader a view

in perspective of a large part of the field of evolutionary thought

and investigation. This is true in particular of the newer aspects of

evolution, concerning which most of all a book of this sort was needed.

Lectures 1 and 2 are introductory in character. In them are dis-

cussed the limitations of evolution, the fact that it cannot explain

everything, the beginning of the universe being quite beyond its

sphere. The relation of science to religion is discussed and the

absence of any real conflict between the two is shown; the ultimate

questions of being and of consciousness are found to be beyond solution

either by science or by religion. Lecture 3 deals with the origin of

the earth, the newly discovered transmutation of one element into

another, the origin of life and the fact that among organisms as among

the elements one form may give rise to another. The dependence of

organic form upon two sets of factors is noted, one set internal, the

other external. Lecture 4 is devoted to the external factors or ‘“mor-

phogenic stimuli," such as light, heat, pressure, chemical composition

! Lotsy, x P. Vorlesungen über Deszendenztheorien mit besonderer Berück-

sichtigung botanischen Seite der Frage. Teil I. Jena, Gustav Fischer,

1906. 8vo, ngewe pp., 2 pls., 124 text-figs.

No. 474] NOTES AND LITERATURE 457

of surrounding media, ete. Lecture 5 deals with adaptations and

theories as to their origin, whether internal or external. Lectures

6 to 11 are on heredity. Spencer’s comparison of heredity to regen-

eration of a broken crystal is shown to be incorrect by the fact of

heteromorphosis among organisms. Nägeli’s idioplasm theory and

Weismann’s germ plasm theory are shown to have been important as

forerunners of the still more important ideas of de Vries, though all

of these were anticipated in part by the work of Gregor Mendel.

One of the lectures on heredity is devoted wholly to an exposition

of Mendel’s law (of alternative inheritance); another to variation

curves, particularly to Galton’s pioneer work in this field; another to

filial regression, under which head are discussed the divergent views

of Galton and Johannsen on regression, and the part played by the

ancestors in the laws of heredity of Galton and Mendel respectively.

In the final lecture on heredity the nature of the gametes (sex-cells) is

shown to be the crucial question with theories of heredity, since in

the gametes are contained all the internal factors of form. e

phenomena of atavism, reversion, and latent inheritance (cryptomery,

Tschermak) here come up for consideration.

Lecture 12 deals with the vexed question of the inheritance of ac-

quired characters, which the author answers with a qualified affirm-

ative; Lecture 13, with discontinuous variation as illustrated in the

varieties of canary-birds, pigeons, and poultry, and among plants by

numerous cases taken mostly from the works of de Vries and Kor-

shinsky. 'Then follow two lectures devoted to the mutants of de

Vries. In the next six lectures is given a historical survey of theories

of evolution up to the time of Darwin, with a brief account of Darwin's

life. In a subsequent volume the author proposes to discuss the Dar-

winian theory and the post-Darwinian literature.

The volume already issued is a marvel of prompt publication

admirably done. The preface is dated September 11, 1905, and the

plates contain half-tone illustrations made from photographs taken in

September, 1905. Three months later the finished work is delivered

in America, yet no evidence of haste is seen in the execution of the

work; it is up to the usual standard of Fischer's publications, which

statement in itself is sufficient praise.

W. E. C.

458 THE AMERICAN, NATURALIST [Vor. XL

EXPLORATION

Scott's Voyage of the ‘Discovery’.'— At the beginning of the

‚seventeenth century, knowledge of the Antarctic regions was so meager

that Quiros, a Portuguese favored by Pope Clement VIII, obtained

permission from Phillip III, the King of Spain, to “prosecute a voyage

to annex the South Polar continent and to convert its inhabitants to

the true faith." Quiros never reached the Antarctic Circle but since

that time, the occasional visits of navigators have added slightly to

our scanty knowledge of this distant part of the earth, although real

scientific work did not begin until the middle of the eighteenth century,

when, in 1773, James Cook, with two vessels especially fitted for

exploration, first crossed the Antarctic Circle. About 1820, Bellings-

hausen discovered the first known land (Peter Island) within the

Antarctic Circle, and later in the century other expeditions touched

.at various points of the Antarctic continent and brought back more

-or less fragmentary and imperfect accounts of that region.

The last decade has seen great activity and interest in the investiga-

tion of this area, so that in 1901 no less than three expeditions, work-

ing in coóperation, were sent out to undertake a more exact study

of the Antarctic seas and lands. The German expedition was led

by Drygalski, the Swedish was in charge of Dr. O. Nordenskjöld,

while the third, under the auspices of the Royal Geographical Society

of London was commanded by Captain Robert F. Scott, R. N. The

two volumes here reviewed, present a straightforward narrative of

the work of the English party as modestly told by Captain Scott

himself.

The preliminary chapters deal briefly with the previous explorations,

the circumstances leading up to the organization of the expedition,

the construction of the Discovery especially built for hard work in the

ice, ave equipment of the vessel, and the personnel of her officers and

"Sailing from England in July, 1901, the Discovery reached New

Zealand in due course and on December 24, following, steered south

Tor Victoria Land, the portion of the Antarctie continent assigned to

this expedition for exploration. The remainder of the short polar

1 Scott, Robert F. The Voyage of the ‘Discovery.’ New York and London,

‘Charles Scribner’s Sons, 1905. 8vo, 2 vols., illus. $10.00

No. 474] NOTES AND LITERATURE 459

summer was spent in a preliminary reconnaissance of the coastline

and the final selection of a favorable wintering spot in McMurdo

Sound to the southeast of the volcanoes Erebus and Terror. Much

of the coast thus visited was practically unknown and new land was

discovered to the west of the Great Ice Barrier and was named King

Edward VII Land. It was also determined that the Ice Barrier at

this point had receded since the time of Ross’s visit in 1841-2, and

that the voleanoes Erebus (active) and Terror are upon an island.

In February, 1902, the Discovery anchored in the spot selected for

winter quarters. Huts were erected on shore for the magnetic in-

struments and the routine of general scientific work was at once

inaugurated. By the last of March, 1902, the vessel was frozen

solidly into the ice, and throughout the Antarctic winter the scientific

work was continued without interruption. By the first of November

following, with the return of the sun, Captain Scott, Dr. E. A. Wilson,

and Shackleton started on an extended sledge journey to the south.

This party, traversing the surface of the Great Ice Barrier, followed

south along the range of mountains that evidently represents the

rugged coastline at this point, and after untold hardships returned

at the end of three months having reached latitude 82° 16’ 33” S.,

the most southern point ever attained by human beings. At this

turning place, a lofty mountain was seen to the southwest and named

Mt. Markham (15,100 ft.) while other great ranges stretched away

to the south-southeast.

A second winter was spent in McMurdo Sound as the ice did not

release the Discovery from its winter quarters. The little company

was in good condition for the second season and the arrival of the

relief ship M manng made it possible to recruit certain stores for

another summer’s work. This consisted chiefly in an expedition to

the west to explore the Ferrar Glacier and the great tableland beyond

which was found to rise for some 9000 feet. Over this inhospitable

area Captain Scott and two other picked men made a remarkable

journey on foot, and found it a “‘vast plain.... the most desolate

region in the world," barren, deserted, windswept, and piereingly

cold. The glacier and the Great Ice Barrier appear to be parts of

the slowly receding outskirts of a polar ice cap that formerly was

far more extensive.

By February of the following year, the ice floe broke up and the

Discovery, in company with two relief ships, was enabled to return

to New Zealand and thence home to England.

In his closing chapters, Captain Scott makes a few general remarks

460 THE AMERICAN NATURALIST [Vor. XL

on the nature of the land masses, the ice, and the ocean currents of

these seas, and the two appendices by Ferrar and Wilson respectively,

give a brief account of the geology and of the larger vertebrates. The

observations on the penguins are of particular interest. The breeding

grounds of the Emperor Penguin were for the first time discovered

and valuable observations on the breeding habits were made at Cape

Crozier where a small rookery was found. With respect to the so

called ‘pouch’ of this and the King Penguin in which the egg is said

to be carried, Dr. Wilson writes: “‘We are agreed that the term

‘pouch’ which has been used in this connection, is one which not

only does not describe the matter, but is anatomically wrong and

misleading. The single egg, or the chick, sits resting on the dorsum

of the foot, wedged in between the legs and the lower abdomen; and

over it falls a fold of heavily feathered skin, which is very loose, and

can completely cover up and hide the egg or chick from view." This

appearance is excellently shown in an accompanying photograph.

Although the scientific results have not yet been fully published, it

seems certain that they will be the most valuable hitherto obtained

by any Antarctic expedition.

The two handsome volumes of this work are well printed and

abundantly illustrated with remarkably clear photographs as well as

by numerous colored plates from sketches by Dr. Wilson. Two

folding charts show in detail the coast of Victoria Land, the new land

features discovered, and the routes taken in exploration. As a con-

venient method of keeping the reader informed of the lapse of time

during the course of the narrative, the month and year corresponding

to the time of the incident related, are printed at the upper inside

margin of each page. The narrative itself is of intense and absorbing

interest to the naturalist and the general reader alike, and is re-

commended to any who may be skeptical of the value of polar explor-

ation. For in the author's own words: “The voyage of the ‘Discovery’

was not conducted in a spirit of pure adventure, but we strove to add,

and succeeded in adding, something to the sum of human knowledge.”

6: M. A

No. 474] NOTES AND LITERATURE 461

BOTANY

Anther Dehiscence.— A study was begun in 1901 in connection

with an article on the pollination of Solanum and Cassia, published

in the Kansas University Seience Bulletin, and continued in 1903 in a

thesis presented to the faculty of Washington University for the degree

of doctor of philosophy. The author recognizes seven types of api-

cally dehiscent anthers and designates them as araceous, gramineous,

polygalaceous, ericaceous, dilleniaceous, Solanum-Cassia, and mela-

stomataceous. First, these types are defined and the families and

genera representative of each are indicated. Then there follows an

account of the floral ecology of the forms, except of the first four types.

Seven tables give the results of the arrangement of the data relating

to the geographical distribution of the genera of the several types,

and one shows the distribution of the flowering plants in general.

Fourteen geographical regions are recognized, based on the floristic

regions of Drude. The Tropical American Region shows a maxi-

mum of Phanerogamia, the Indian Region being second.

The dilleniaceous, Solanum-Cassia, and melastomataceous types

have the corolla, or at least the limb, widely patent, and the anthers

basifixed and usually linear.

In the dilleniaceous type the stamens are indefinite, the anthers

usually elongate, the flowers usually actinomorphic and highly colored.

To this type are assigned 16 genera belonging to 6 families: five genera.

of Dilleniaceze, five of Eleeocarpacer, three of Ochnacez, one each of

Theacex, Bixacee, and Flacourtiacee. An Indian maximum is

indicated for this type, the Tropical American and Australian Regions

being next with the same number of genera; the Tropical American

Region, however, shows more species than the Australian. As visi-

tors there have been observed: bees — Xylocopa, Euglossa, Bombus,

Apis, Melipona, Halictus, Centris, Podalirius; birds —a brush-

tongued paroquet, Charmosyna, a honey-sucker, Myzomela; flies

— Muscidee

The Solastiin-Cusda type differs from the dilleniaceous in the

stamens being fewer and the filaments short. In this category fall

‘Harris, J. Arthur. “The Dehiscence of Anthers by Apical Pores.” From

the Sixteenth Annual Report of the Missouri Botanical Garden, pp. 167-257,

issued May 31, 1905.

462 THE AMERICAN NATURALIST [Vor. XL

59 genera belonging to 19 families, 6 of which are Monocotyledons.

The Monocotyledons are: one genus of Mayacaces, six of Rapa-

teaceze, two of Commelinacex, one of Pontederiacex, five of Lili-

aces, four of Amaryllidacee. The Dicotyledons are: one genus of

Pittosporacez, nine of Leguminoss, three of Tremandracee, four of

Sterculiaceze, eleven of Ochnacex, two of Dipterocarpacez, one of

Flacourtiacez, sections of Begonia in Begoniaceze, sections of Ardisia

in Myrsinacex, one of Loganiacex, two each of Gentianacex Solan-

aces, and Rubiacex. The table for the Solanum-Cassia type shows

a maximum for the Tropical American Region, with the Australian

Region second. Genera of visitors observed on flowers of this type

are: bees — Osmia, Megachile, Ceratina, Xylocopa, Euglossa, Bom-

bus, Apis, Trigona, Melipona, Halictus, Augochlora, Megacilissa,

Melissodes, Podalirius, Centris, Oxeea; flies — Rhingia, Volucella;

butterflies — Argynnis; birds — Mimus, Nectarinia, Chlorostilbon.

'The melastomataceous type differs from the preceding mainly in

the long filaments and in both locules of the anther usually opening

through a single pore. Of the 161 genera of Melastomataces it

includes all except 12, besides one genus of Leguminose and two of

Bixacez. The Tropical American Regien contains about 63 % of

plants of the melastomataceous type, the Indian Region showing

about 20 %. The observed visitors are: bees — Xylocopa, Bombus,

Trigona, Halictus, Centris; flies — Syrphide; beetles — Cetonia,

Buprestis; birds — Trochili

The table of genera of the fee types shows a Tropical American

maximum of about 57 %, and an Indian elevation of about 21 95. In

Apide the Tropical American Region is first, with 64 genera of bees,

the Mediterranean-Oriental Region second, with 51, the Northern

Region third, with 50. Table J shows the distribution of Hymenop-

tera of all genera. K shows the relative abundance of genera of Apide.

Diagram L gives curves for the distribution of endemic genera of the

apically dehiscent types, of the Phanerogamia, of the Apide, and of

all Hymenoptera. Diagram M shows the relative distribution of all

genera of the same groups.

These curves indicate a direct relationship between the geographical

distribution of the Apide and of the dilleniaceous, Solanum-Cassia,

and melastomataceous floral types.

C. RoBERTSON

No. 474] NOTES AND LITERATURE 463

Freeman's Minnesota Plant Diseases. — Simplicity, attractive-

ness, and full illustration are among the qualities of an ideal publica-

tion on agricultural science if it is to reach the people without the

intervention of a middle-man. These qualities are possessed by a

recent book on the diseases of plants prepared by Professor Freeman

under the direction of the Geological and Natural History Survey of

Minnesota,— a State which spends large sums annually on the study

of its native resources and limitations, but the Agricultural Experi-

ment Station of which is said never to have employed a special plant

pathologist. The treatment falls under three general heads: fungi

and their life history; economic applications; and diseases of plants.

The book is likely to realize its author’s hope of making the intelligent

farmer who may read it an intelligent observer and assistant to the

expert investigator.

Ward's Flowers of English Trees and Shrubs.’— This volume,

the third in the author’s work on trees, is devoted to a study of the

flowers and inflorescences of the woody plants of England. It is

essentially a book for the layman. It is to be recommended for its

reedom from those grievous errors which so often characterize the

“popular” books of a certain class of literary aspirants in this coun-

try. The amateur student will receive all the aid and instruction he

needs, while the technical student will find a large amount of valuable

material presented in a lucid and concise form.

The first part of the book is general and is devoted to a study of

the more common types of flowers and inflorescences. The reader

is first introduced, by means of a few well chosen examples, to the

typical inflorescences and then to their variations. There next fol-

lows a treatment of the flower, its different parts, their nature and

development. The general part of the book concludes with two

chapters on the ecology of the flower. Naturally, these chapters

concern themselves with the process of pollination and the characters

of the flower which are correlated therewith. The entire material

of Part I is admirably selected and lucidly set forth.

The second part of the book is special and takes the form of a man-

‘Freeman, E. M. Minnesota Plant Diseases.— Report of the Survey, Botan-

ical Series, v. St. Paul, published by the Regents of the University, July 31,

1905. 8vo, xviii + 432 pp., 211

? Ward, H. Marshall. Trees, Vol. IH. Flowers and Inflorescences. Cam-

bridge, University Press, 1905. 12mo., 402 pp., 142 figs.

464 THE AMERICAN NATURALIST [Vor. XL

ual for the classification of the common English trees, based upon

their flowers and inflorescences. The willows are treated separately

in an appendix. Tables are there given for the classification of wil-

lows when pistillate or staminate catkins are alone available.

The book is concluded with a copious glossary which defines the

technical terms necessarily used in a book of this sort.

H-6 K

Notes.— Dr. Scotts Wilde lecture on the “ Early History of Seed-

bearing Plants as Recorded in the Carboniferous Flora” is published,

with illustrations, in vol. 49, part 3, of the Memoirs and Proceedings

of the Manchester Literary and Philosophical Society.

The classification of Monocotyledons is further discussed by Delpino

in series 5, vol. 10, of the Memorie della R. Accademia delle Scienze of

Bologna.

A short illustrated note on the bark characters of trees, by Peet,

is contained in The Country Calendar for November, 1905.

An address on plant morphology and taxonomy, by Kraemer, is

published in the American Journal of Pharmacy for September, 1905.

A paper on contractile vacuoles and the frothy structure of pro-

toplasm, by Degen, forms Heft 9-11, Abteilung 1, of the Botanische

Zeitung for 1905.

Lindemuth (Die Gartenwelt, Oct. 28, 1905) has propagated Rex

begonias from the leaves with long petioles. The petiole strikes root

from the base and produces a crown of leaves at the tip. The petiole

undergoes no great modification in form or structure except to increase

somewhat in size but it may function as the stem of the plant for a

long period of time.

The influence of color in floral ecology is analyzed in a paper by

Delpino forming part of series 6, vol. 1, of the Memoire della R. Ac-

cademia delle Scienze of Bologna.

Studies on the composition and metabolism of apples, by Bigelow,

Gore, and Howard, form Bulletin 94 of the Bureau of Chemistry,

U. S. Department of Agriculture.

The influence of environment upon the composition of the sugar beet

is discussed by Wiley in Bulletin 95 of the Bureau of Chemistry, U.

S. Department of Agriculture.

No. 474] NOTES AND LITERATURE 465

The variability of wheat varieties in resistance to toxic salts is the

subject of Bulletin 79 of the Bureau of Plant Industry, U. S. Depart-

ment of Agriculture.

A paper on the vitality of buried seeds, by Duvel, forms Bulletin

83 offthe Bureau of Plant Industry, U. S. Department of Agriculture.

A mechanical study of thistle-down as a parachute is published by

Dandeno in Science of November 3, 1905.

Figures of some natural tree grafts are published by M. P. Wheeler

in The American Inventor for November.

An analysis of the plant geography of Canada, by Drummond,

appears in vol. 8, part 1, of the Transactions of the Canadian In-

stitute.

Plants characterizing the life zones of Texas are listed by Bailey

in N orth American Fauna, no. 25.

The forest conditions of the Gila River Forest Reserve, N. M., are

discussed by Rixon in Professional Paper 39 of the U. S. Geological

Survey.

A note on G. J. Graham and his Mexican collections of 1827-9 is

published by Britten in The Journal of Botany for November.

A popular account of Mexican vegetation, with instructive habit

photograms, is published by Purpus in Möllers Deutsche Gärtner-

Zeitung of October 7.

Five new Mexican flowering plants are described by Rose in no.

1427 of the Proceedings of the U. S. National Museum ; a new mono-

typic genus (Harperia) of Umbelliferee and a new Zizia, from Georgia,

are described by the same author in no. 1428 of the same publication,

and Rose and House describe three Mexican violets (one new) in the

succeeding no. 1429.

Part 7 of Captain J. Donnell Smith’s Enumeratio Plantarum Guate-

malensium has recently been distributed by the author.

The grasslands of the South Alaska coast are discussed by Piper in

Bulletin 82 of the Bureau of Plant Industry, U. S. Department of

Agriculture.

The relations of the floras of the Northern Atlantic, the Polar Sea,

and the Northern Pacific are considered by Simmons in Bd. 19, Heft 1,

of the second Abteilung of Beihefte zum botanischen Centralblatt.

466 THE AMERICAN NATURALIST [Vot XL

De Wildeman has begun the publication, through the Government

of the Etat Indépendant du Congo, of an illustrated enumeration of

the plants collected by Laurent during his Congo mission of 1903-04.

Important papers on Australasian botany are contained in current

issues of Proceedings of the Linnean Society of New South Wales and

the biological section of the Reports of the Australasian Association

for the Advancement of Science.

Ridley has papers on Gesneracex of the Malay Peninsula, Aroids

of Borneo, and New and Little-known Malayan Plants — II, in no.

44 of the Journal of the Straits Branch of the Royal Asiatic Society,

issued in July last.

Cooke’s Flora of the Presidency of Bombay, in vol. 2, part 2, issued

in July last, reaches into the Verbenace:e.

Schlotterbeck and Blome contribute a paper on the chemistry of

Bocconia cordata to the Pharmaceutical Review for October, 1905.

A morphological and anatomical study of Claytonia, by Holm,

forms vol. 10, no. 2, of the Memoirs of the National Academy of Sciences.

Britten publishes a note on Cliftonia in The Journal of Botany for

October, 1905.

Interesting statistics of the cotton production and valuation of the

world are furnished by Watkins in Bulletin 34 of the ze. of Sta-

tistics, U. S. Department of Agriculture.

An account of “Cratsegus in Eastern Pennsylvania," distributed

by Sargent on September 22 from the Proceedings of the Academy of

Natural Sciences of Philadelphia for 1905, gives keys to the groups

and species represented, of which latter 82, with 3 distinct varieties,

are included,— 46 of the species being described as new.

A paper on Opuntia, by Berger, is contained in Engler’s Botanische

Jahrbiicher of November 10, 1905.

Townsendia wileoxiana is figured in vol. 5, fascicle 3, of Icones.

Selecte Horti T henensis.

Antennaria neodioica g ‚s is a new form from eastern Quebec,

described by Fernald in The Ottawa Naturalist for November.

Power and Barrowcliff discuss the seed constituents of Hydnocarpus

and Gynocardia in nos. 54 and 55, respectively, of the publications of

the Wellcome Chemical Research Laboratories, of London.

No. 474] NOTES AND LITERATURE 467

An illustrated account of Solanum commersonii is contained in

Gartenflora of September 1, 1905.

A chemical analysis of Tecoma mollis, by Kebler and Seidell, forms

Circular 24 of the Bureau of Chemistry, U. S. Department of Agri-

culture.

Illustrated articles on mangroves are contributed by J. A. Dimock

and A. W. Dimock to Country Lije in America for November, 1905.

Warburg gives an account of Phthirusa and Strutanthus — the

mistletoes of rubber — in Der Tropenpflanzer for November, 1905.

Five additional species, and two varieties, are added to the hitherto

monotypic genus Osmaronia by Greene in the concluding signature

of Pittonia, vol. 5.

Habit figures of Grammatophyllum speciosum, a giant orchid, are

given by Ridley in the May number of the Agricultural Bulletin of the

Straits and Federated Malay States.

The somewhat aberrant nomenclature needs of orchid hybrids are

discussed by Bohlmann in Die Gartenwelt of November 11, 1905.

The Xanthosomas cultivated under the name Yautia form the sub-

ject of Bulletin 6 of the Porto Rico Agricultural Experiment Station,

issued in English and Spanish.

No. 24 of Holm's “Studies in the Cyperacez," published i in The

American Journal of Science for September, 1905, deals with new or

little known Carices from northwest America.

A well illustrated monograph of the wild and cultivated grasses of

Iowa, by Pammel, Ball, and Lamson-Scribner, forming part 2 of “The

Grasses of Iowa," has been issued as a Supplementary Report of the

Iowa Geological Survey.

“Poa and its Commercial Fruit Characters" is the subject of Bulletin

84 of the*Bureau of Plant Industry, U. S. Department of Agricul-

ture by Brown and Hillman.

Cavendish reports, in The Indian Forester for August, that after

an interval of some 30 years Dendrocalamus hamiltonii has flowered

throughout the Assam district in the wholesale fashion characteristic

of the bamboos.

The storage and germination of Zizania seed is the subject of Bul-

letin 90, part 1, of the Bureau of Plant Industry, U. S. Department

of Agriculture.

468 THE AMERICAN NATURALIST [Vou. XL

A Spanish hybrid of Juniperus phenicea and J. communis is de-

scribed by Cadeval y Diars in vol. 5, no. 12, of the current series of

Memorias de la Real Academia de Ciencias y Artes de Barcelona.

The third and concluding volume of Braithwaite’s British M 088

Flora has recently appeared from Reeve's of London

A new Index Filicum, by Christensen, is being issued in fascicles

from the Hagerup press of Copenhagen. All of the pteridophyte

names published from 1753 to 1905 are included, the treatment being

much as in the Index Kewensis devoted to spermatophytes.

An extensive paper on the anatomy of Acrostichum aureum is pub-

lished by Ethel A. Thomas in The New Phytologist of October 25,

1905. . .

A new fern (Polystichum krugii) from Porto Rico is described by

Maxon in the Proceedings of the Biological Society of Washington for

October 17, 1905.

Laing contributes a revised list of New Zealand seaweeds, and the

first part of an account of the Ceramiacee of the island, to vol. 37 of

the Transactions and Proceedings of the New Zealand Institute, —

which contains numerous other botanical papers of interest.

A series of 64 unusually good three-color plates illustrates Dumée's

Nouvel Atlas de Poche des Champignons Comestibles et Vénéneua,

recently published by Klincksieck of Paris.

Publication no. 28 o] the Bureau o] Government Laboratories, Manila,

consists of papers by Copeland on “ The Polypodiaces of the Philip-

pine Islands" and * New Species of Edible Philippine Fungi."

Under the title Die Pilze von Tirol, Vorarlberg, und Lichtenstein,

Magnus has published, through the Wagner press of Innsbruck, a

volume of 716 pages containing an account of over 3500 species, with

bibliography, notes on synonymy, habitat, etc. "The very full indexes

alone occupy over 100 pages.

A voluminous catalogue of the fungi of the Low Countries, by the

venerable Oudemans, constitutes vol. 12 of the second section of Ver-

handelingen der Koninklijke Akademie van Wetenschappen of Amster-

dam.

An account of Norwegian Hymenomycetes, begun by Blytt and

finished by Rostrup, has been separately issued from the Videnskabs-

Selskabets Skrijter of Christiania, for 1904.

No. 474] NOTES AND LITERATURE 469

Guzmän enumerates 40 Salvadorean oil plants, cultivated or wild,

in vol. 2, no. 14, of the Anales del Museo Nacional of El Salvador.

The destructive occurrence of Trametes pini in India is noted by

Mayes in The Indian Forester for July, 1905.

Mushroom-growing and tissue-culture spawn production are de-

seribed by Duggar in Bulletin 85 of the Bureau of Plant Industry,

U. S. Department of Agriculture.

A twin specimen of Geaster jornicatus is figured in the Gardeners’

Chronicle of November 4, 1905.

The nuclear and sexual phenomena of Phyllactinia and other

mildews are described by Harper in the recently issued Publication

no. 37 of the Carnegie Institution of Washington.

A paper on the Monoblepharidex, by Woronin, forms vol. 16, no. 4,

of the Mémoires de l'Académie Imperiale des Sciences de St. Péters-

bourg.

A note on the Tuberacex of Portugal is published by Mattirolo in

the Atti della R. Accademia dei Lincei, Roma, of October 15, 1905.

Uncinula conidiigena is the name of a new parasite of Populus

termula, described and figured by Cocconi in series 5, vol. 10, of the

Memorie della R. Accademia delle Scienze of Bologna.

Uromycladium is the name proposed by McAlpine for a genus of

South Pacific leguminous rusts, related to Uromyces and Ravenelia,

in Annales Mycologici for August, 1905.

The Japanese species of Uromyces on Sophora and Cladrastis are

analyzed by Kusano in the (Tokyo) Botanical Magazine of August

20, 1905.

An account of endophytic adaptation shown by Erysiphe graminis

under cultural conditions, is given by Salmon in vol. 198, series B, of

the Philosophical Transactions of the Royal Society of London.

Diachea cylindrica, a new Pennsylvanian species, is described by

Bilgram in the current volume of Proceedings of the Academy of Nat-

ural Sciences of Philadelphia.

In a brochure recently issued from the Engelmann press of Leipzig,

von Guttenberg considers the physiological anatomy of the galls pro-

duced by fungi.

470 THE AMERICAN NATURALIST [Vor. XL

Wheat improvement is considered by Lyon, in Bulletin 78 of the

Bureau of Plant Industry, U. S. Department of Agriculture.

The well known odor of moldy straw and hay is ascribed to a Strep-

tothrix by Brocg-Rousseu in the Revue Generale de Botanique for

October 15, 1905.

Hedgeock, in Bulletin 90, part 2, of the Bureau of Plant Industry,

U. S. Department of Agriculture, differentiates the prevalent “crown

gall" of apple trees into crown gall proper, and “hairy-root.” The

second is found not to be contagious, and the contagiousness of the

first is not demonstrated.

A paper on the indigenous calabashes of Mexico, the Ayotli of

Hernandez, is published in vol. 1, no. 2, of the Anales de la Academia

Mexicana.

An illustrated article on Burbank and his work, by Honoria Tuomey,

is contained in Out West for September, 1905.

Britten and Woodward have published some interesting corre-

spondence concerning L’Heritier in recent numbers of The Journal

of Botany.

Another of Fraser's Catalogues — this for 1796 — is reprinted in

The Journal oj Botany for November, 1905.

The recently issued 1904-05 Report oj the Government Botanist

for the Cape of Good Hope shows that the Cape herbarium now con-

tains 44,189 sheets of specimens, of which 25,400 represent the Cape

flora,— some 3000 of these being type sheets left by Harvey.

A new publication of the Tiflis Botanical Garden has been begun,

under the title Moniteur du Jardin Botanique de Tiflis.

A series of illustrated articles on the London botanical gardens

is being published by Perrédés in current numbers of the American

Journal of Pha

A well illustrated account of the botanical garden at Buitenzorg is

contributed by Ramaley to The Popular Seience Monthly of November.

The Carnegie Laboratory at Tucson is described by Wittmack in

Gartenflora of October 15, 1905.

An account of Dr. Kunze and his cactus collection, by Willey, is

contained in The American Inventor for October, 1905.

No. 474] NOTES AND LITERATURE 471

Karasek gives an illustrated account of vegetation in the gardens

of German Africa, in the Wiener illustrierte Gartenzeitung for Novem-

ber, 1905.

The Journals — The Botanical Gazette, September: — Blakeslee,

“Two Conidia-bearing Fungi"; Mottier, “The Development of the

Heterotypic Chromosomes in Pollen Mother Cells”; Livingston,

“Relation of Transpiration to Growth in Wheat”; Arthur, “Rusts

on Composite from Mexico”; Shattuck, “A Morphological Study of

` Ulmus americana” ; Billings, “‘ Precursory Leaf-serrations of Ulmus” ;

Sheldon, “ The Effect of Different Soils on the Development of the

Carnation Rust."

The Botanical Gazette, October: — McCallum, “Regeneration in

Plants — II"; Brown, “A Botanical Survey of the Huron River

Valley — III"; Lyon, “The Spore Coats of Selaginella”; Schneider,

“Contributions to the Biology of Rhizobia — V"; Eckerson, “The

Physiological Constants of Plants Commonly used in American Botan-

ical Laboratories — I"; Kraemer, “Further Observations on the

Structure of the Starch Grain."

T he Botanical Gazette, November: — Peirce and Randolph, “Studies

of Irritability in Alge”; Transeau, “‘The Bogs and Bog Flora of the

Huron River Valley"; Ball, *Notes on North American Willows —

: ded

The Bryologist, November:— Haynes, “ Telaranea nematodes longi-

folia”; Sargent, “Lichenology for Beginners — IV"; Chamberlain,

“Some Common enu. Hill, “Encalypta procera"; Merrill,

“Lichen Notes — I"; Holzinger, “A Note on Local Moss Distri-

bution."

Bulletin of the Torrey Botanical Club, September: — Harper,

" Phytogeographical Explorations in the Coastal Plain of Georgia

in 1904"; Murrill, “The Polyporacee of North America— XII,

A Synopsis of the White and Bright Colored Pileate Species"; Mac-

kenzie, “ Onosmodium.”

Bulletin of the Torrey Botanical Club, October: — Cannon, “A

New Method of Measuring the Transpiration of Plants in Place”;

Harris, “The Fruit of Opuntia”; Abrams, “Studies on the Flora of

Southern California"; Piper, “Agropyron tenerum and its Allies";

Cushman, “The Desmid Flora of Nantucket."

The Fern Bulletin, July: — Clute, “Species and Varieties among

the Ferns”; Gilbert, “Observations on North American Pterido-

a2 THE AMERICAN NATURALIST [Vor. XL

phytes"; Clute, “A Walking Shield Fern"; Gilbert, “Some Mexi-

can Fernworts”; Terry, ‘‘More about the Ferns of Dorset"; Klugh,

* Nephrodium Boottii or N. spinulosum X cristatum”; Eaton,

“ Botrychium biternatum."

The Journal of Mycology, July: — Morgan, “A New Species of

Kalmusia”; Morgan, “Peziza pubida"; Davis, “A New Species of

Synchytrium”; Holway, “North American Salvia-Rusts”; Cleven-

ger, “Notes on some North American Phyllachoras”; Lawrence,

“Blackspot Canker and Blackspot Apple Rot”;. Sumstine, “ Gom-

phidius rhodoxanthus once more”; Sherman, “The Host Plants of

Paneolus epimyces”; Kellerman, “Notes from Mycological Litera-

ture — XVI,” and “Index to North American Mycology.”

Journal of the New York Botanical Garden, September: — Britton,

“A Lost Species of Begonia [B. rotundifolia] tly Rediscovered” ;

Hollick, ** Paleeobotanical Notes”; MacDougal, 23 Suwarto or Saguaro.”

Mühlenbergia, vol. 1, no. 7: — Heller, “The Western Veratrums,”

and “A New Linanthus."

Mühlenbergia, vol. 2, no. 1, is occupied by an account of botanical

exploration in California during 1905, by the editor, Mr. Heller.

The Ohio Naturalist, November: — Surface, “ Contribution to the

Life History of Sanguinaria canadensis” ; Schaffner, “ The Classifica-

tion of Plants — II"; Fischer, ‘‘ An Abnormal Cone of Pinus laricio" ;

Gleason, “Notes from the Ohio State Herbarium — IV."

_ Appropriate space is devoted to botany in the Ontario Natural

Science Bulletin,— the newly launched journal of the Wellington

Field Naturalists’ Club, of Guelph, Ontario.

The Plant World, August: — Bessey, “How much Plant Pathology

ought a Teacher of Botany to know?"; Reed, “A Brief History of

Ecological Work in Botany (Conclusion)"; Nehrling, “An Indian

Magnolia [Talauma hodgsoni] in America."

The Plant World, September: — Atkinson, “Outlines for the Ob-

servation of some of the more Common Fungi"; Lloyd, “ The Barley

one— I. Some Points of Structure"; Kinney, ‘Outline of a Course

in Plant Culture."

. Rhodora, September: — Pease, “Notes on the Accentuation of

Certain Generic Names"; Sargent, “Recently Recognized Species

No. 473] NOTES AND LITERATURE 473:

of Crategus in Eastern Canada and New England — VI”; Fernald,

“Symphoricarpos racemosus and its Varieties in Eastern America”;

Howe, “Lotus tenuis as a Waif in Rhode Island”; Collins, “Phy-

cological Notes of the late Isaac Holden — I.”

Rhodora, October: — Sanford, “ Eclipta alba in Mass.”; Sargent,

“Recently Recognized Species of Crateegus in Eastern Canada and

New England—VI (continued)”; Fernald, “An Anomalous Alpine

Willow”; Lewis, “Sclerolepis in N. H.”

The first volume of the Proceedings of the American Breeders’ As-

sociation, containing an account of the St. Louis meeting of 1903 and

the Champaign meeting of 1905, has recently been issued, and con-

tains a large number of unusually practical and some theoretical

articles on both animal and plant breeding.

Torreya, September: — Greene, “Origin of Rhus bipinnata”;

Harris, “New Fasciations"; Tidestrom, “Note on Botrychium vir-

ginianum" ; Harper, Some Large Specimens of Small Trees in Ga.” ;

Clark, *Cotyledon- and Leaf-structure in Certain Ranunculacee” ;

House, “Lespedeza velutina Bicknell a Homonym.”

Torreya, October: — Tidestrom, “Notes on the Gray Polypody";

Lloyd, “ The Artificial Induction of Leaf Formation in the Ocotillo” ;

Berry, “An Old Swamp-Bottom"; Harper, “ Mesadenia lanceolata

and its Allies."

Zoe, August: — T. S. M id ** A Collection of Mexican Plants";

“Palms of Baja ran ; “A New Calamintha”; “ Plants from

Sinaloa, Mexico” retia, "New Spean of Mexican Plants'';

Katharine Ende ^ ‘Notes on Cactez.”

(No. 473 was issued May 9, 1906)

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CONTENTS

Page

Adaptive Modifications of Occipital Condylesin Mammalia . .C8. MEAD 475

. E. W. BERRY 485

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III. Notes and Literature: Paleontology, Jd s Guide to the Study of

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THE

AMERICAN NATURALIST

Vor. XL July, 1906 No. 475

ADAPTIVE MODIFICATIONS OF OCCIPITAL

CONDYLES IN MAMMALIA

CHARLES S. MEAD

HISTORICAL

A NUMBER of papers have been written on the occipital condyles

but they deal with them from either an ontogenetic or a phyloge-

netic standpoint. Osborn (:00) has shown that certain of the

mammals, such as Tachyglossus (Echidna) and Cercoleptes, pos-

sess but a single tripartite condyle continuous across the median

plane by a narrow bridge; that others, such as Lutra, have the

condyles widely separated and that between these two extremes

there are intermediate stages, showing thus that the “mammalian

occipital condyles arose from a reptilian tripartite type by the

reduction of the median eis. see element and the expansion

of the lateral exoccipital elements.”

Gadow (:02), from a study of the anterior cervical Re in

the various vertebrates, comes to the conclusion that “the original

craniocervical joint must have been a paired one, formed by the

lateral occipitals with their more or less serially homologous parts,

the neural arches of the first free vertebra. A single condyle

could be formed only after the centrum of the first vertebra had

been withdrawn as the odontoid process, so as to let the neural

arches and the ventral unpaired piece of the atlas . . . . form a cup.”

Hence he reverses Osborn’s order and looks upon the “ monocondy-

lar, essentially basioccipital knob, as the final outcome of evolution,

independently arrived at by various groups of Sauropsida.”

The origin of the condyles needs to be examined further from

475

| 476 THE AMERICAN NATURALIST (Vor. XL

this point of view, attention being paid especially to the “proatlas”’

which Broom (:03) has described in Gomphognathus and Trira-

chodon. It also occurs in the Rhynchocephalia and the Croco-

dilia, and Broom predicts that it will yet be found in most of the

primitive reptilian types.

Fischer (:01) has shown that in the ls of the mole

(Talpa europea) the lateral condyles are confluent around the base

of the foramen magnum, while in the adult they are separate. He

apparently supports Osborn’s position in the following sentence:

“ The most important thing to me is the fact that the configuration

of the occipital joint in our mole occupies a sort of intermediate

position between the mammals and the Sauropsida."

From a study of the chondrocranium of Lacerta agilis, Gaupp

(:00) directly supports Osborn. He finds four craniovertebral

connections: a dorso-median (the ligamentum apicis dentis), the

two lateral corresponding with the lateral condyles of the mammals,

and a ventro-median (the median basioccipital element of Osborn)

which connects the two lateral parts in the Sauropsida, but which

is lost in the mammals. However, he is mistaken in saying (p.

493) that a direct articulation of the ventral part of the atlas with

the ventral surface of the basioccipital is lacking in the mammals,

for although such an articulation does not occur in the generalized

forms, it does occur in some of the specialized, such as Cercoleptes,

Gulo, and Taxidea.

GENERAL ADAPTATION OF CONDYLES

The object of the present paper is to point out the types of con-

dyles found among the mammals and to give, so far as possible, the

adaptive significance of the several types.

Some 2500 skulls belonging to the American Museum of Nat-

ural History and to Columbia University have been examined, and

I wish to thank Professor Osborn for his help and suggestions

which he has so willingly given.

"The occipital condyles are very important, since it is by them

that the head articulates with the neck. The head can usually be

moved freely in all directions, and in some animals is frequently

| subjected to great strains, and in order that it may not be dislocated

No. 475] OCCIPITAL CONDYLES IN MAMMALIA 477.

easily the condyles have become modified in various ways. After

giving the various modifications I will attempt to correlate the differ-

ent types with the habits of the animals, giving, so far as possible,

a mechanical explanation for the unusual forms.

They can only be understood in connection with (1) the atlas

and axis and (2) the musculature of the occiput and neck. There

is a mechanical balance of the ligaments and opposing muscles so

that the head is held, with the least amount of effort, in its normal

resting position.

The degree of mobility is directly correlated with the curvature

of the condyles, and to some extent with their sessile or peduncu-

late position (Fig. 12, a and d). The sessile condition never occurs

except when the neck is short. When the head can be turned

through a large are the condyles are strongly curved and peduncu-

late. ‘This is beautifully shown in the birds, in which the single

median condyle is pedunculate and hemispherical, an arrange-

ment that permits free motion in all directions. Fig. 12, e, shows

a sagittal section through a hawk’s condyle and f a transverse sec-

tion. The transverse diameter of the two condyles together is

always greater in the mammals than the fore-and-aft diameter.

There are three ways of moving the head: up and down, side-

ways, and in a torsional or twisting manner. Among the mam-

mals, the movement up and down occurs mostly between the atlas

and the skull. The torsional movement is mainly between the

atlas and the axis, the odontoid process acting as a pivot around

which the atlas revolves. To move the head sideways all the

cervical vertebra come into play.

TRANSITION BETWEEN MOoONOCONDYLIC AND POLYCONDYLIC

CONDITIONS

The monocondylic tripartite and dicondylic conditions are well

illustrated in Osborn’s paper (:00), the dicondylic condition being

. derived from the monocondylie by the reduction of the median

element.

But reduction does not always occur in the median plane. In

some specimens of Gulo the condition is monocondylie (Fig. 4),

while in others reduction has taken place, not in the median plane,

478 THE AMERICAN NATURALIST [Vor. XL

but at some distance each side of it, producing a tricondylic con-

dition. This third condyle (Fig. 6, b), articulates with the basal

part of the atlas when the head is bent downwards sharply, and

may be known as the “median condyle." In many mammals the

odontoid process is long and when the head is thus sharply bent

upon the neck, the process comes in contact with the basioccipital

producing a facet (Fig. 6, a),

which we will call the **odontoid

condyle." In the sea otter, Latax

lutris (Fig. 7), the odontoid and

median condyles have each been

divided by a depression thus pro-

ducing four accessory condyles or

six altogether!

'This is a process of reduction,

the articular faces increasing in

number but decreasing in total

area, possibly to be correlated

with the manner of feeding and

the character of the food, prin-

cipally shell fish, the head and

neck losing some of their mobility

and not being subjected to such

great strains as in the more car-

nivorous forms. It is only com-

paratively recently that they have

.1-4— 1, Echidna; 2, Putorius; 3, adopted their present habits, and

1 z : :

Cerco en d bienes "m d pes with a con- so the reduction of the median

w sauna as forward, giving condylar area has not been car-

a large area of articulation. All? nat- , * . .

ural size. ried to the point of obliteration,

since the atrophy of an organ

always is slower than its development.

Thus we may look upon the condyles of such a form as Erinaceus

as representing a generalized type. Here they are separated by an

interval equal to one half the diameter of one of them, they are

uniformly curved throughout and not prolonged forward, nor are

they noticeably sessile or pedunculate.

No. 475) OCCIPITAL CONDYLES IN MAMMALIA 479:

ADAPTATION TO CARNIVOROUS HABITS

As the animal became more carnivorous in its diet, capturing

larger animals, the condyles became larger and stronger, extended

forward, became approximated, and

finally fused, forming a type with a

large condylar area (Figs. 4 and 5).

Later, as the animal gave up its habit

of capturing large prey and took to

feeding on smaller animals, the

condylar area suffered reduction,

since such strong condyles were not

needed, the reduction occurring first

at each side of the median line (Fig.

6), and later in the sagittal plane

(Fig. 7).

_ Thus we'get a type with the lat-

' eral condyles widely separated and

poorly adapted for fighting. If,

from the generalized type, the

animals have adopted habits requir-

(7 ( É ing little or no fighting, and feeding

cath. po^ habits requiring no great develop-

FUN. ment of the neck muscles for pulling

and tearing, the condyles never

acquire a large articulating area, but

dica : 9 ;

A 3 remain small and tend to become

further separated from each other,

— as in Homo and Tatusia. In both

s ville pieg ». M NE of these, the ancestral forms have

with divided condyles. a, odontoid the condyles approaching an Erina-

e; 6, median occipital condyle. %

All ł natural size. ceus-like type.

In the early ungulates (Panto-

lambda, Phenacodus, Hyrachyus, etc.) the condyles are of a gen-

eralized type, while in some of the later forms (Ovis, Camelus,

Equus) they are highly specialized, being large, and having a

peculiar shape. This has probably been brought about by their

480 THE AMERICAN NATURALIST (Von XL

manner of fighting among themselves, and will be discussed far-

ther on. ER

The position of the head upon the neck has a great deal to do

with the direction in which the condyles point, whether straight

backward, as in the cetaceans, or downward as in man.

ARRANGEMENT OF CONDYLES IN DIFFERENT ORDERS

Monotremata.—The condyles are very thick and rounded (Fig. 1).

The odontoid process is long and has a broad basioccipital facet,

which, at the sides, may or may not be confluent with the lateral

condyles, this being an individual variation.

Marsupialia.— The condyles are, as a rule, pedunculate and

strongly convex, and often widely separated. In Didelphys and

Dasyurus there is a slight tendency to bridge over the basioccip-

ital, while an odontoid facet occurs in a few.

Insectivora.— In the burrowing forms, Scapanus, Scalops, and

Talpa, the neck is very short and the condyles large and sessile,

and extended slightly forward, due to the sessile condition and

relatively large size. The odontoid process is long, articulating

with the basioccipital. In the less specialized forms, such as Eri-

naceus, the condyles represent a very generalized type.

Cheiroptera.— All the bats have the condyles separated; usually

widely so in the Microcheiroptera, where they are sessile. In those

forms that carry the head at right angles to the vertebral axis, the

condyles point downward, as in man, while in the large Pteropus,

they are directed backward.

Edentata.— All the living Xenarthra have the condyles very

widely separated (Fig. 8), but in Metacheiromys, an armadillo

from the middle Eocene, they are nearly in contact ventrally.

odentia.— Various conditions are met with among the rodents

but none worthy of note except that in Lepus. In this form (Fig.

9), the condyles are not only convex dorso-ventrally, but also trans-

versely, their long axes being directed upward and outward. '

Carnivora.— The carnivores very: often worry their prey, shak-

ing their heads from side to side, and after it is dead, tearing the

flesh from the body. In this latter process the head is sharply

flexed upon the neck, so that any further ventral motion is stopped

No. 475] OCCIPITAL CONDYLES IN MAMMALIA 481

by the ventral portion of the atlas coming. in contact with the

median condyle or with the anterior prolongation of the lateral

condyles, and, since strong ligaments prevent any dorso-ventral

motion between the atlas and the axis, any further strain in this

direction will be thrown back upon the other cervical vertebre,

where the processes and muscles are stronger and there is no dan-

ger of dislocation. The anterior prolongation of the lateral con-

dyles occurs only in the more strictly carnivorous forms. ‘The

median condyle and its separation from the lateral condyles is well

shown in the Mustelide (Figs. 2-4, 6, and 7). The lateral con-

dyles are usually prolonged forward in the Canidze and Hyenide,

and these, together with the Mus-

telidæ, feed in a standing position,

not in a crouching position as do

the others.

Cetacea.— All have short necks

with a tendency for the cervicals

tofuse. The condyles face direct-

ly backwards. Inall recent forms

examined the condyles were ses-

sile and only slightly convex (Fig. -

12, a). In the Miocene forms

(Argyrocetus, Hypocetus, etc.)

the condyles were somewhat pe-

dunculate and strongly convex; > F |

they had long flexible necks and pies, 10:11. 10, Camelus; 11, Ovis.

the head was easily turned, ascon- faris types with tne, conde pro-

trasted with the living cetaceans.

None of the ungulates has a median condyle, nor an odontoid

facet upon the skull, nor are the condyles ever confluent ventrally.

Perissodactyla.— The horses always have the condyles pro-

longed forward, and they are sometimes slightly concave antero-

posteriorly at their forward ends.

Correlated with the downward extension of the condyles is the

folding over of the condylar articular surface of the atlas onto

its anterior face. The tapirs parallel the horses. Neither the

titanotheres nor the rhinoceroses have the condyles prolonged

forward.

482

THE AMERICAN NATURALIST [Vor. XL

Artiodactyla.— All the horned rumi-

nants have the condyles extended for-

ward and broadened out and curved

downward at their anterior ends. Cor-

related with this, as in the horses, the

articular surface of the atlas is extended

downward on its anterior face. In fight-

ing, the head is bent downward so that the

points of the horns will project forward

towards the foe. In this position the head

interlocks with the atlas so that when

the two animals come together with a

rush, there can be no dislocation.

The atlas and axis are firmly bound

together by ligaments, so that the force

of the impact is thrown back upon the

body and posterior cervicals where there

is no danger of a dislocation as there is

no sharp flexion. Fig. 12, h and i,

cross sections of the condyle and atlas

of the aoudad (Ovis tragelaphus), shows

how the two are reciprocally curved at

their ventral ends. The dotted line of

Fig. 11 shows where section h was taken.

A similar condition occurs in the hornless

females and in the camels and horses.

The females of the horned forms have

probably inherited this peculiarity from

the males; no reason is known for its

occurrence in the camels and horses.

E: T ; Primates.— In the lemurs the condyles

mue point backward while in the Anthropoidea

Fie, 12.— a, Monodon; b, Homo; c, Dasyurus; d, Rhinoceros; e, Archibuteo,

sagittal section; 7, tra nsverse section of sam me; g, Camelus; h, Ovis trage-

laphus; i, section through atlas of same. Sections through the left condyle

be opposite section h in its natural position, shows how the condylar

articular surface is curved over onto its anterior face. All drawn the same

mparison.

No. 475] OCCIPITAL CONDYLES IN MAMMALIA 483

they are usually placed under the cranium and directed downward.

They are always widely separated, except in some of the lemurs.

Occasionally the odontoid process articulates with the skull (Homo,

Cercocebus, some lemurs); no median condyle occurs. On the

median part of the condyles there is usually a depression, which

in some forms becomes a sharp notch.

In some of the mammals (Hyena, Tragulus, Equus, Ovis, Came-

lus, Figs. 10,11, and 12, g), the articular surface of the condyles,

instead of having a continuous curve, possesses a ridge running

obliquely outward and upward from about the middle of the inner

border of the condyles. No explanation is offered for this peculiar

condition as it apparently reduces the efficiency of the condylar

articulation. The habitual position of carrying the head, and its

direction with reference to that of the atlas, will probably offer

some explanation.

BIBLIOGRAPHY

Broom, R.

:03. On the Axis, Atlas, and Proatlas in the Higher Theriodonts.

Proc. Zool. Soc. London, pp. 177-180.

FISCHER, E.

:01. Primordialeranıum von Talpa europea. Ein Beitrag zur

Morphologie der Säugetierschädels. Anat. Inst. d. Univ. Frei-

burg i. Br., 1901, p. 539.

Gavow, H. i

102. Origin of the Mammalia. Zeitschr. f. Morph. u. Anthr., vol. 4,

part 2.

Gaurr, E.

:00. Das Chondrocranium von Lacerta agilis. Anat. Hefte, vol. 15,

pp. 43

OsnonNw, H. F.

:00. Origin of the Mammalia, III. Occipital Condyles of Reptilian

Tripartite Type. Amer. Nat., vol. 34, pp. 943-947.

LIVING AND FOSSIL SPECIES OF COMPTONIA

EDWARD W. BERRY

INTRODUCTION

WHEN we find a genus which is monotypic in the existing flora,

or one which contains but two or three geographically remote

species, we may rest assured that the genus in question had an

interesting geological history, and that its living representatives

are relicts of a day when the genus was widespread and dominant.

Notable examples, such as Liriodendron, Sequoia, and Nelumbo,

may be cited. Comptonia is no exception to this rule. The single

living species is confined to eastern North America, ranging as a

low shrub from Nova Scotia to Manitoba and southward to North

Carolina, Indiana, and Tennessee, while the number of ancient

forms that have been described, is upwards of three score and

amply proves the cosmopolitan character of the genus during the

Tertiary period.

Recent paleobotanists refer them as a subgenus to Myrica, as

is done in case of the living species by Engler (Natürlichen P flan-

zenfamilien, vol. 2, pt. 1, p. 28, 1889). Modern usage in this

country, however, gives Comptonia generic rank, quite rightly so

it seems to me.

The space of a generation has passed since Schimper’s classic

Traité de Paléontologie Végétale sought to unify paleobotany, and

the chaos of described species is even greater to-day than it was

previous to 1870. Paleobotany is surely far enough advanced,

it seems to me, for a more philosophical treatment, and while this

little essay makes no pretension at embodying such a treatment,

it is hoped that it will furnish the material that will be useful for

that purpose when the proper time arrives.

It is obvious enough to most botanists that existing species vary

in their leaf characters through very wide limits. I have had con-

siderable to say about the leaf variation, atavistic and otherwise,

485

486 THE AMERICAN NATURALIST [Vor. XL

of Liriodendron and Sassafras, and the same variability is true of

that most interesting relic of bygone days, the Ginkgo; while

numerous instances of similar variations in other genera could

be cited. For a number of years I have been engaged in collect-

ing leaf specimens to illustrate this variability in a number of

genera, and I find this task to be a never-ending source of interest

in addition to the invaluable data which it furnishes for the

understanding of earlier floras.

If it be objected that the consideration of geographically widely

removed forms as identical leads only to confusion, the answer is

—a consideration of the variability in the living Comptonia, the

unmistakable proof in its present and past distribution of its wide

range, coupled with the tendency to call a certain form by a cer-

tain name because it is like a form perhaps wrongly named by

Brongniart or Heer or Lesquereux, without a very serious con-

sideration of the generic affinities, in fact it can scarcely be said

that we have any generic limits in a host of Mesozoic and Neo-

zoie.genera; all these tend to discredit specific distinction based

on geographical remoteness.

These considerations lead me to think that the present is not

an inopportune time for an attempt to work out the relations of

such forms as may be referred to Comptonia, and to see if even a

little light cannot be shed on their history. And at the same time

to reduce the number of species (so called), often based as they

are upon irrecognizable fragments. Surely several score of spe-

cies, some entirely inadequate, leave room for more confusion

than slight errors in the opposite direction. The forms here con-

sidered as identical all show such slight variations as would not

be considered for a moment were we dealing with leaves in the

existing flora.

THE SUCCESSION OF FORMS

Comptonia branched from the Myrica stock, most probably

during the lower Cretaceous. Its original home was in all prob-

ability in the greatly extended lands of the semitropical or

warm temperate Arctic region, although the earliest known speci-

No. 475] REVISION OF COMPTONIA 487

men from that region is from the Cenomanian of Greenland (Atane

beds). One of the first floral migrations southward. during the

Mesozoic was along the Atlantic coastal plain, which at that time

was possibly continuous along the northeastern coast of America

from Greenland south. "Traces of this ancient coastal plain are

said to have been found off the present New England coast, and

the difficulties of accounting for the remarkable similarities in

the Cretaceous flora of Greenland and that of the Atlantic coastal

plain seem insurmountable unless we predicate some sort of a

direct land connection, so that floral distribution tends to fur-

nish support to Suess’s theory as to the origin of the Atlantic ocean.

The Myricas were a prominent element in this Mesozoic migra--

tion, a single species being recorded from the lowermost Creta-

ceous of Virginia. In strata of approximately Albian age (Raritan,

etc.) there are ten species of Myrica, and at this time occurs the

earliest known Comptonia, in the Raritan of New Jersey.

The resemblance of this and other primitive Comptonia leaves

to those juvenile and atavistic leaves of the modern species is dis-

cussed in a later portion of this paper.

That Comptonia is derived from Myrica, aside from the mor-

phological and other evidence furnished by a study of existing

species, seems probable (1) from the fact that it originated among

an abundant display of Myrica species some of which preceded

it in time, (2) from its progressive increase in the number of species

and in their ever widening distribution up to the close of the

Miocene, paralleling a like history for the genus Myrica, (3) the

numerous leaf remains that have been found intermediate in

character between Myrica and Comptonia, (4) the resemblance to

Myrica of the oldest Comptonias and of the leaves of modern

seedlings.

As an example of the variation in Myrica leaves and their ten-

dency to approach the Comptonia form, I may cite Myrica lignitum

Unger, an undoubted Myrica, abundant in the Oligocene and

Miocene of Europe. Ettingshausen and Standfest' in their study

of the abundant remains of these leaves from the late Tertiary of

! Ettingshausen und Standfest. “Ueber Myrica lignitum Ung., und ihre

Beziehungen zu den lebenden Myrica Arten.” Denkschr. math.-natur. Akad.

Wiss. Wien, vol. 54, pp. 1-8, pls. 1, 2, 1888.

488 THE AMERICAN NATURALIST [Von XL.

Styria, recognize thirty varieties of which several are very close to

Comptonia, in fact were it not for the closely related intermediate

forms as well as the characteristic Myrica fruit, we would be jus-

tified in considering them as referable to Comptonia.

Contemporaneous with the southward advance of Comptonia.

in eastern North America, we find a like advance through north-

ern Europe via the then extended Scandinavian peninsula, recorded

by a primitive species of Comptonia (antiqua Nilss.) from the

greensand of Köpinge, Sweden, followed by the appearance of the

same species in Transylvania (Cenomanian). This species is

very close to its American and Arctic congeners, so similar that one

cannot but see in these leaves the strongest sort of an argument for

a common ancestry, a theory which receives additional strength,

not only from the form of the juvenile leaves of the existing species,

but also from the fact that there is nothing in our present knowledge

of floral distribution in past time or of the disposition of the land

masses of the northern hemisphere during the Mesozoic that does

other than add support to such a theory.

Some authors (e. g., Hosius and von der Marck) would include

Dryandra cretacea of Velenovsky from the Cenomanian of Bohemia

in this genus. While it is true that the form and venation of the

leaves is the same as that characterizing the leaves of certain Mio-

cene species of Comptonia, and that with the aid of mutation (as.

used by deVries, not Osborn) there would be no difficulty in deriv-

ing this species from the contemporaneous Myrica stock, especially

when we note that we have no evidence that in habit and structure

it differed from the contemporaneous Myricas, the only differ-

ence about which we know anything is the difference in leaf-form,

“and the evolution of leaf-form is a comparatively simple affair.

Still I think that the inordinate length of these specialized leaves,

combined with the character of the marginal serrations, together

with their geological position, renders it probable that Dryandra

is a more reasonable index of their real botanical relations. I

certainly do not feel that the evidence is sufficient for making, the

change in generic affinity suggested.

The upper Cretaceous history of Comptonia is a blank in so far

as America is concerned. In Europe, however, we find a char-

acteristic Comptonia (tenera Hos. & v. d. Marck) in the Senonian

No. 475] REVISION OF COMPTONIA 489

of Westphalia. This species shows a considerable progression

from the earlier Cretaceous form, and clearly foreshadows the

later type of leaf, so abundant in the Tertiary floras, and which is

not very different from the typical modern leaf.

With the ushering in of the Eocene, we find this type of leaf con-

tinued in considerable abundance and showing more or less varia-

bility in the direction of other species. ‘The European records

of this age are far superior to those of America; while the Arctic

region unfortunately has thus far furnished no evidence (except

for the single leaf which I have referred to Comptonia microphylla

and whose age is doubtful).

The Atlantic coastal plain, where we would expect to have

found a most interesting group of species, had the records only

been preserved, fails us entirely, as no leaf beds have been found

in their marine formations. Western America it is true furnishes

us with Eocene Comptonias, but these are relics of an independent

line of migration from the Arctic region during which three species

occurred in Alaska. These either represent the genus en route for

Asia, or are stragglers which were left behind during the Asiatic ad-

vance. The Green River beds, besides some fragmentary remains,

furnish us with a beautiful species, which we picture as a promi-

nent element in the flora that clothed the site of the present Rocky

Mountain region.

Asia has thus far failed to show Comptonias in strata earlier

than the Miocene, due no doubt to our lack of knowledge of earlier

Tertiary formations and floras in that region. As previously

mentioned it is in Europe that we find the most satisfactory evi-

dence of Comptonia development.

Beginning with the same type of leaf as that of the Senonian

tenera, which is common during the Eocene as Comptonia schrankii,

and which becomes widespread, we find various lines of variation

leading to the closely related and equally abundant Comptonia

diforme, and to the less common forms which I have shown in

the genealogical diagram.

We find at this time the modern type of leaf and the same varia-

tions from this type, 7. e., small leaves, large leaves, leaves with

acute lobes, and leaves with obtuse or rounded lobes; in all, some

twelve forms which appear to be valid species.

490 THE AMERICAN NATURALIST [Vor. XL

The next period, the Oligocene, shows a considerable broaden-

ing out in their development and distribution. From the vindo-

bonensis type we get, by a series of slight gradations, Comptonia

eningensis, and by equally slight steps this type gives rise to that

most beautiful species, Comptonia laciniata with its large leaves

and serrated lobes. This form is strongly suggested in the leaves

of the modern species. The small-leaved types of schrankii and

diforme continue through this period, and near them we have the

large and handsome form, Comptonia dryandroides, so like the

modern leaf, besides two or three other species of more doubtful

value — in all twelve species.

It-is in the next period, however, the Miocene, that the genus

reaches its acme of development. Numerous leaf remains, often -

beautifully preserved, are present at nearly every locality where

plant beds of this age have been opened, from Greece and Bohemia

‘to France and the Baltic. We find a continuation and further

development of all of the Oligocene types, the small schrankti with

both rounded and acute lobes, the somewhat larger and rather

acute-lobed diforme, the obtuse-lobed «eningensis and vindobo-

nensis, and the related large-leaved laciniata and dryandroides,

besides numerous other forms, including the gigantic grandifolia.

We find laciniata getting over into Asia Minor from southeastern

Europe. Eastern Asia (Japan) furnishes two good species which

are identical with European forms. Northwestern America fur-

nishes two additional forms also identical with European forms,

one of them being the same as one of the forms from Japan.

Whether we have in these occurrences the evidence of an inter-

change of species between the continental regions or independent

lines of southward migration from the Arctic region is not posi-

tively determinable. I incline to the latter assumption, however,

which is supported by the evidence of dryandroides (cuspidata of

Daws.) from western Canada which is identical with naumann?

Nath. from Japan, both in turn identical with the leaves which

occur in southeastern Europe from this and earlier horizons. It

would seem that the Japanese and Canadian leaves had both

traveled southward along the foothills bordering the valleys, which

in their general trend run north and south, rather than that they

came overland from Europe to Asia then across Behring Straits

No. 475] REVISION OF COMPTONIA 491

and down the western American coast or vice versa. In all, we

have during the Miocene, forms which may be divided up into

nine “good species."

With the refrigeration of Pliocene and Pleistocene climates

in temperate latitudes, and the resulting wholesale extinction

and redistribution of species, we see Comptonia exterminated

from all except American soil. The story is apparently the

same for numerous other genera which are exclusively American

in the existing flora; the Mediterranean Sea in Europe and the

high altitudes of southern Asia apparently cutting off their

retreat before the advancing ice sheet.

Comptonia is a hardy shrub at the present time and thrives in

almost any habitat, possibly as the result of its struggles with

severe conditions during the Glacial period.

VENATION

In spite of the considerable variation in leaf-form shown by the

leaves of Comptonia peregrina (Linn.) Coulter, the venation is

monotonously uniform. In a general way it may be character-

ized as follows: there are two or three secondaries in each lobe,

generally two in the smaller lobed forms and three in the larger,

although those with two seem to be the commoner irrespective

of size. They all branch from the midrib at a wide angle, often

90 degrees, and describe a slight upward curve, which is greater in

the lobes toward the tip of the leaf. The uppermost secondary in

each lobe usually runs directly to the tip of the lobe when the lat-

ter is pointed, or directly to the margin in those leaves with rounded

lobes, its position on the margin being indicated by a slight mu-

cronate point. The one or two secondaries below the upper are

inserted at equal distances apart and become somewhat more

curved as they proceed outward, curving upward to join a short

downwardly directed lateral branch from the secondary next

above. The tertiary venation in the border region is festooned

along the margin of the leaf, being particularly noticeable along

the lower margins of the lobes. Where the lobes have a somewhat

serrated margin or are divided somewhat similarly to those of

492 THE AMERICAN NATURALIST [Vor. XL

the fossil species Comptonia laciniata, this arching of the veins

along the border is more or less interfered with, and a branch

from the nearest secondary proceeds to the tip of the tooth.

Where the lobes are not separated to the midrib there is usually

a vein of the same caliber as the secondaries which proceeds

directly to the sinus between the lobes, where it forks and its

two branches arch along the borders of the adjacent lobes on

each side (above and below). The finer areolation shows three-,

four-, or five-sided reticulations. On the whole the venation can-

not be said to show any especially characteristic and distinctive

features. The usual style of leaf is finely figured by Schimper

in his Traité de Paléontologie Végétale, Plate 84, Fig. 4 (1874),

which is copied from a figure of Ettingshausen, in his Blattskelette

der A petale.

REVERTED FORM OF SEEDLING LEAVES

In discussing Comptonia microphylla I have mentioned the curi-

ously shaped leaves of the seedlings of the existing species, the

first six or seven of which are indistinguishable from those of

the earliest Comptonias from the Mid-Cretaceous, and which

are evidently true reversions. Some of these are well shown on

Plate 3. I have collected numerous examples of these leaves and

believe this form to be a constant feature of the seedling leaves,

furnishing admirable proof of the correct identification of their

Cretaceous ancestors.

As might be expected, the various fossil species of Comptonia

probably had leaves on their seedlings which were similar to this

form. Seedling plants, as can be readily understood, are rare as

fossils. I am convinced, however, that the leaves which Heer!

refers to Myrica latiloba from the Miocene of Locle and Oenin-

gen are to be so understood. Their form and venation are exactly

that of the modern seedling leaves and they have the same thin tex-

ture and thickened midrib. Lesquereux’s Fig. 12 of Myrica alka-

lina from the Green River group of Wyoming is also a young leaf,

probably of Comptonia insignis (Lx.) Berry.

! Heer. Fl. Tert. Helv., vol. 3, p. 176, pl. 150, fig. 12-15, 1859.

No. 4751 REVISION OF COMPTONIA 403

STIPULES

The stipules on the modern plant are large, ordinarily of an

odd, three-lobed form, the upper lobe being produced into a horn

which runs close to the petiole. These stipules are pronounced

in seedlings and spring shoots, no doubt serving as a protection

from the cold. ‘They become, however, much reduced in size and

abbreviated in form on the later shoots. ‘They are also very vari-

able, some of the extreme forms being shown on Pl. 1, Figs. 8-12,

Figs. 11 and 12 being the more typical. Asin Liriodendron, they

are probably descended from the basal lobes of the leaves of their

ancestors, for we find basal lobes in the modern plant which

approximate the stipular form and which are entirely separated

from the lobes next above. Pl. 1, Figs. 4-7, illustrates some of these _

basal lobes and serves admirably to show how strikingly they

approximate the stipules in appearance.

COMPOUND LEAVES

The leaves of the modern species show occasional examples of

a tendency toward the formation of compound leaves. Usually it

is toward the tip that the midrib forks, forming two lobes. Some-

times, however, a basal lobe will assume the size and proportions

of a division of a compound leaf. On Pl. 1, Figs. 1-3, are shown

three examples of this tendency. In Figs. 1 and 3 the midrib

forks about halfway to the tip, thus forming two divisions of equal

rank. In Fig. 2 the tendency seems to be toward a tripalmate

division, the central division being bilobed and separated by an

interval of petiole (midrib) from the rest of the leaf.

I know of no fossil remains which approach these modern leaf

variations.

It has been suggested to me that the leaf variations in the exist-

ing species may indicate that this apparently monotypic form may

be segregated into a number of closely related species, like so many

aggregations of the Asa Gray period. This may be so; it were

rash nowadays to doubt the possibilities of any species in this direc-

tion after seeing what has happened and is happening to Crategus

494 THE AMERICAN NATURALIST [Vor. XL

and other genera. However, no evidence in this direction is fur-

nished by the variations in leaf form, for with the exception of the

atavistic character of the seedling leaves which appears to be a con-

stant feature, and the usual reduction shown by the senescent

leaves, the leaf variation is entirely fortuitous, if one may use that

term in this sense for the result of unknown, or at least not well

understood morphological and physiological causes.

THE FossıL SPECIES

That the number of fossil species of Comptonia has been multi-

plied beyond what the facts warrant, seems probable without any

very serious consideration. ‘That we should have, for instance,

in the area of Europe, ten or a dozen Eocene, Oligocene, and

: Miocene species seems improbable, and this off-hand conclusion is

borne out by an examination of the species. We find that the limits

of variation within a single species as conceived by the various writ-

ers who have studied members of this genus, judging by the diverse

forms referred to the same species, are so wide as to include in

almost any of the described species (so called), greater differences

of size, form, or venation than exist between what are usually

regarded as really valid species by the individual authors. In

addition we find species founded upon obscure fragments of doubt-

ful value, or upon what are very probably immature or abnormal

leaves. More especially does this seem to be the case when we

examine the leaves of the sole existing species for comparison. ‘The

latter show wide variations (see Pl. 2). The typically mature

leaves are usually divided nearly to the midrib, although the

sides of the lobes often overlap, giving them the appearance in

some cases of being only slightly incised. This would be par-

ticularly true of similarly lobed leaves preserved as fossils. The

leaves are progressively simpler toward the flowers and in the

seedlings, becoming merely serrate or even entire and lanceo-

late (Pl. 3). Thus the juvenile and senescent leaves are both

more or less atavistic. The lobes vary greatly in outline dup-

licating many of the fossil leaves in appearance; their margins

are usually entire but may be incised as in several of the fossil leaves.

On the whole I feel justified in suggesting the changes which

No. 475] REVISION OF COMPTONIA 495

follow, the discussion falling naturally under the respective species.

While the synonymy does not pretend to be complete, I have en-

deavored to include all references to figured specimens and have

been at much pains to verify them in so far as the facilities of the

United States National Museum and the New York Botanical

Garden would permit.

Work of this sort is as laborious as it is unappreciated, indeed

the author who has the temerity to break away from the traditional

names in paleobotany is more than likely to be criticised for having

“done nothing but burden an already overburdened synonymy.”

I have been working on Comptonia for several years and have

long hesitated about publishing my results for just this reason

until perfectly convinced that it was entirely impossible to get any

idea of the past history of the genus without correlating the various

remains, either positively or at least provisionally. To leave them

_ as they were would be about as sensible as it would be to have

species of Comptonia in the existing flora based upon the polit-

ical divisions in which the plants are found and further depend-

ent on the slight variations in leaf-form exhibited by the individual

plants. A number of doubtful forms such as Comptonia cont-

zeniana Debey, Comptonia chironis Massal, Comptonia heerii

Ettings., etc., and such obvious errors as Comptonia mirabilis

Brongn. cited in Prestwich’s Geology are entirely omitted.

Comptonia diforme (Sternb.) Berry

Asplenium dijorme Sternb., Fl. d. Vorwelt, vol. 2, pp. 29, 33, pl. 24, fig. 1,

822.

Aspleniopteris difformis Sternb., Ibid., vol. 4, p. 21, 1825.

Zamites difformis Presl. in Sternb., Ibid., vol. 2, p. 198, 1822.

Buettner, Rudera Diluvii Testes, pl. 22, fig. 8, 1710.

Pterophyllum difformis Göpp., Ubersicht. d. Arb., p. 137, 1844.

Comptonia acutiloba Brongn., Prod., pp. 141, 143, 209, 1828; Tabl.,

p. 121, 1849.

Unger, Synopsis, pp. 213, 305, 1845; Gen. et Sp., p. 393, 1850; Foss.

Fl. v. Sotzka, p. 32 (162), pl. 8 (29), figs. 6-8, 1850.

Saporta, Périd. Végét., p. 307, fig. 92; Mon. d. Pl., 1879; Orig. Pal.

Arbes. Cult., p. 141, 1888.

Gardner, Mem. Geol. Surv. Eng. & Wales, p. 108, 1889.

Boulay, “Fl. foss. Gergovie,” Ann. Sci. Brux., vol. 23, p. 73, 1899.

496 THE AMERICAN NATURALIST [Vor. XL

Dryandra acutiloba (Brongn.) Ettings., Proteac. d. Vorw., p. 27 (735),

pl. 4 (33), figs. 2, 3, 1851; Foss. Fl. v. Bilin, vol. 2, p. 17, pl. 35, figs.

18-26, 1868; Proc. Roy. Soc. Lond., vol. 30, p. 232, 1880.

Myrica (Comptonia) acutiloba Brongn.

Schimp., Pal. Végét., vol. 2, p. 560, 1872.

Engelhardt, Nova Act. Leop. Carol., vol. 39, p. 375, pl. 23, figs. 7-12,

877; Ibid. vol. 57, p. 153, pl. 6, figs. 4-7, 1891; Sitzb. naturwiss.

Gesell. Isis, 1880, p. 78, pl. 1, figs. 6, 7, 1881; Lotos, neue

folge, Bd. 16, p. 5, 1896.

Heer, Fl. Foss. Arct., vol. 7, p. 77, 1883.

Dryandra comptoniefolia Ettings., Beitr. z. kr. joss. Fl. Neuseelands,

p. 27, pl. 4, figs. 14-18a; pl. 5, figs. 9-12, 1887.

Comptonia columbiana Daws., Trans. Roy. Soc. Can., vol. 8, sec. 4, p. 81,

fig. 10 (text), 1890.

Comptonia Vinayi Saporta, Pl. joss. Ark. de Brives, p. 35, pl. 3, figs.

9-13, 1878.

Dryandra saxonica Friedrich, Abh. geol. Specialk. Preuss u. Thüring.,

vol. 4, pp. 327, 382, pl. 20, figs. 10a-16; pl. 28, CER 3-5; pl 29, fig.

16, 1883.

'This was one of the first known species of Comptonia, having

been described and figured by Sternberg in 1822 under the name

Asplenium diforme. What is probably the same thing is mentioned

elsewhere in his Flora der Vorwelt as Aspleniopteris difformis

Sternb. and Zamites difjormis Presl. A similar leaf was figured

by Buettner as long ago as 1710 and considered as having Cyca-

dean relationships.

We have in this species, or group of species of the acutiloba type,

a widespread and persistent type of leaf which is fairly well marked.

Some of the smaller specimens, it is true, resemble Comptonia

schrankii, particularly Ettingshausen's forms from Monte Promina,

but the bulk of the leaves referred to the latter species are smaller

and have very narrow, two-veined, acute lobes. Heer includes

under Comptonia acutiloba the Comptonia incisa of Ludwig found

at several localities in Hesse, and he also identifies a similar leaf

from Greenland as Comptonia incisa. The Greenland leaf is

identical with Ludwig's leaves, but both are obviously distinct

from C. acutiloba

Dawson's form from British Columbia belongs here. He says

that it is closely allied to Comptonia matheroniana Sap., but I fail

to see any resemblance to that species. Species which do resemble

No. 475] REVISION OF COMPTONIA 497

Dawson’s more or less, are Comptoniphyllum japonicum Nath.,

and especial y Comptonia partita Lesq., the latter based upon a

poorly drawn fragment from the Green River beds.

The existing Comptonia sometimes furnishes leaves very similar

to diforme, and I have collected many such, although usually they

differ in being somewhat broader, e. g., Pl. 2, Fig. 4

The many excellent figures published by Ettingshausen furnish

adequate and typical examples of the leaves of the species under

discussion. This form of leaf makes its appearance during the

Eocene at the widely separated localities of the Isle of Wight in

England, Brives in France (represented by C. vinayi Sap.), and

Murderer's Creek in New Zealand. It is possible that the

New Zealand leaf, which is identical in form, may have been

borne on an entirely different plant, as it is difficult to account

for so wide a distribution. It may well be that the New

Zealand leaf should be referred to Dryandra as Ettingshausen has

done, since several species of the latter genus have been recorded

from that region by the same author, all having leaves of the acuti-

loba type. In discussions of the distribution of Comptonia we

should constantly bear in mind, however, the meagerness of the

record of the upper Cretaceous period.

Comptonia diforme continued through the Oligocene and Mio-

cene, becoming common during the latter age and occurring in

beds in this country which have been considered Miocene (Comp-

tonia columbiana Daws.).

Friedrich considers the Saxon leaves which he describes under

the name of Dryandra saxonica to belong to that genus because of

their acute lobes, subcoriaceous texture, and style of venation, in

which characters he says they differ from the modern Comptonia

leaf. If he had seen a large enough series of the latter he would

have found no difficulty in recognizing their similarity and the

fact of their identity with both fossil forms whose similarity he

does note, 7. e., schrankii and acutiloba, all of which I have included

under Comptonia diforme.

Comptonia gaudinii Heer

M yrica (Comptonia) gaudinii Heer, Fl. Tert. Helv., vol. 2, p. 34, pl. 70,

fig. 9, 1856; Ibid., vol. 3, pl. 152, fig. 19, 1859.

Schimp., Pal. Végét., vol. 2, p. 559, 1872.

498 THE AMERICAN NATURALIST [Vor. XL

Comptonia incisa Ludwig, «cg vol. 8, p. 96, pl. 30, fig. 7-15, 1860.

Heer, Fl. Foss. Arct., vol. 2, p. 474, pl. 39, fig. 7, 1871 (referred to

Dryandra acutiloba essen.) ‘Sais:

Schimp., loc. eit., p. 561

nn isdágalühs Watelet, Pl. Foss. Bass. Paris, p. 124, pl. 33,

fig. 4, 1

M yrica reiner Engelh., Nova Act. Leop. Carol., vol. 39, p. 376, pl. 23.

fig. 13,

Myrica cones tschernowitziana Engelh., Ibid., p. 375, pl. 23, fig.

onis phglium japonicum Nath., Pal. Abh. D. & K., vol. 4, pp. 207,

212, pl. 20, figs. 2, 3; pl. 22, fig. 3, 1888.

This species embraces leaves approaching the acutiloba type,

averaging, however, considerably larger in size. ‘They are similar

to Comptonia dryandroides Ung. except that the lobes in the latter

species are fewer in number and more falcate in outline. As will

be seen from the foregoing synonymy I have included a variety

of names under this species, most of them having been based upon

fragmentary material. Some of these may be entitled to varietal

rank, but surely their slight differences do not entitle them to rank

as valid species. For instance, Engelhardt’s tschernowitziana is

based upon a single specimen showing but three lobes on one side

and one lobe on the other side. It differs from the typical gaudini?

in the more rounded upper margins of the lobes, but might easily

be a larger leaf of the same author's eredneri, both of which I include

under Comptonia gaudinii. Individual lobes of Ludwig's incisa

which correspond with tschernowitziana could be selected without

much difficulty. Heer’s gaudinii was founded upon fragments.

as was also the Arctie form which he refers to Dryandra acutiloba,

but which seems to belong here. His comparison of gaudinii to

dryandroides Ung. is certainly significant. Watelet’s triangulata.

is another fragment showing only three complete lobes on each side.

Schimper includes it under Watelet's concisa from which it mani-

festly differs, however. Nathorst’s japonicum shows only the cen-

tral portions of several large and small leaves. As might be

expected when dealing with fragments, the various authors com-

pare their specimens with a variety of other species, for instance

Engelhardt compares eredneri with macroloba of Wessel & Weber,

to which I fail to detect any resemblance.

No. 475] REVISION OF COMPTONIA 499

Comptonia gaudinii as here constituted, shows considerable

range, being represented as early as the Eocene by the leaf described

by Watelet which grew on the shores of the Suessonien Gulf, and

continued as late as the Miocene of Switzerland and Japan.

Comptonia insignis (Lesq.) Berry

M yrica insignis Lesq., Ann. Rep. U. S. Geol. & Geog. Surv. Terr., jor

1874, p., 312, 1876; Tertiary Fl., p. 135, pl. 65, figs. 7, 8, 1878.

M yrica alkalina Lesq., Cret. & Tert. Fl., p. 149, pl. 45A, figs. 10-15, 1883.

I regard these two species of Lesquereux as most probably iden-

tical, for example his Figs. 13 and 15 of alkalina are particularly

close to insignis, especially Fig. 15. It would require but a slight

increase in the lobation of the latter to produce the typical insignis.

Other than this the remains of the two forms are exactly alike in

texture and venation, except that in insignis the midrib is more

slender. As Lesquereux remarks, the leaves which he refers to

alkalina are of two types—obtuse, and acute-lobed,— the collected

specimens, however, showing every gradation between these ex-

tremes, some leaves being acutely lobed on one side and obtusely

on the other. As the remains are all from strata of the same age,

although Alkali Station, Wyo., is some 300 miles distant from

Florissant, Col., I am still inclined to think that the leaves which

Lesquereux called alkalina are simply the young leaves of which

insignis is the mature leaf, for they are (1) much more variable

in lobation, (2) smaller in size and definiteness, and in the extent

of their lobes, combined with a narrower lamina, and (3) they

have a much thicker midrib. "This is especially true of Fig. 15

cited above.

All of these are characters which serve to mark the leaves of the

immature plants of the existing species. Together these two types

of leaf show that a most beautiful species of rather broad-leaved

Comptonia dwelt on the site of the present Rocky Mountains dur-

ing the early Tertiary

The venation which is well preserved, shows a type which is

quite characteristic of the modern Comptonia leaf.

I with Myrica vindobonensis Ettings.

and with M yrica ingeri Herr (laciniata Ung.) to both of which

there is a passing resemblance that is by no means close, however.

500 THE AMERICAN NATURALIST (Vor. XL

Comptonia macroloba (Web. & Wess.) Berry

Dryandra macroloba Web. & Wess., Paleont., vol. 4, p. 147, pl. 25, fig.

M rida ROAS (Web. & Wess.) Schimp., Pal. Végét., vol. 2, p. 557,

1872.

Comptonia concisa Watelet, Pl. Foss. Bass. Paris, p. 123, pl. 33, fig. 1,

1866.

Myrica concisa (Wat.) Schimp., Pal. Végét., vol. 2, p. 554, 1872.

These leaves resemble those which have been described and fig-

ured by the respective authors as incisa Ludw. (gaudinii Heer),

dryandroides Ung., and acutiloba (dijorme (Sternb.) Brongn.),

with this difference that the blade in macroloba is incised only half

the distance to the midrib, surely not a very important character

in view of the variation in this direction often shown by the existing

Comptonia.

Watelet's leaf is not different, except in the foregoing particular

from the fragment which he named Comptonia triangulata and

which I have referred to Comptonia gaudinii Heer.

Both of the forms which I have united to form the species under

consideration are fragments of the basal portions of single speci-

mens and possibly their similarity may be due to this fact. Neither

has any individual characters of much specific weight and perhaps

it would be wiser to discard them altogether or to refer them to

some of the above mentioned and better characterized species.

The French specimen is from the lower Eocene while the Prussian

is from the later Tertiary (Aquitanian), which may be considered

an objection to considering them identical. However, they are

of no great importance in any event, and do not throw any addi-

tional light upon the evolution of the genus in Tertiary times.

Comptonia antiqua Nilsson

Phyllites d antiqua) Nilss., Vetens. Akad. Handl., for 1831,

p. 346, pl. 1, fig. 8, 1832.

Sap., Arch. Bei. Phys. & Nat., vol. 28, p. 110, 1867.

Comptonites ? antiquus Nilss., Pf. wear p. 121.

Hisinger, Lethæa Suec., p. 111, pl. 34, fig. 7, 1837.

Unger, Synopsis, p. 213, 1845; Gen. et Sp., p. 395, 1850; Sitzb. Akad.

Wiss. Wien, vol. 51, p. 379, 1865.

Brongn., T'abl., p. 111, 1849.

Dryandra antiqua Ettings., Proteac. d. Vorwelt, p. 31 (739), 1851.

No. 475] REVISION OF COMPTONIA 501

During the time that Comptonia microphylla Heer was spread-

ing southward along the Atlantic coastal plain in America, a very

similarly leaved plant had reached Europe by way of the Scandi-

navian peninsula. ‘This species is represented by the leaf which

Nilsson described in 1832 from the Greensand of Köpinge, Sweden.

That this species became more widespread in Europe than the

fossils which have been discovered show, is indicated by its occur-

rence at almost the opposite end of Europe in the Cenomanian at

Déva, Transylvania.

It was a small leaf with a few rounded lobes and was very simi-

lar in appearance to its Arctic and American congeners. In size

and outline it is identical with Heer’s type figures of Comptonia

parvula and microphylla, particularly the latter, while his Fig. 3 of

the former is indistinguishable from the European leaf. New-

berry’s leaf from New Jersey is larger and has somewhat more

pointed lobes, and Heer’s parviflora is also somewhat larger.

The occurrence of this same type of leaf on the seedlings of the

modern plant, and as the earliest known Comptonia leaves in the

Cretaceous of such geographically remote localities in Europe,

Greenland, and New Jersey, amounts to a demonstration, it seems

to me, that we are dealing with an ancestral form of Comptonia

leaf, and as a corollary, that the j n enile leaf-forms in the modern

plant are truly atavistic.

Comptonia tenera Hos. & v. d. Marck

Comptonia tenera Hos. & v. d. Marck, Pal@ont., vol. 31, p. 227 (3),

pl. 19 (1), figs. 3, 4, 1885.

The next occurrence of Comptonia in Europe after that of Comp-

tonia antiqua Nilss, of the mid-Cretaceous, is this species, which

Hosius and von der Marck found in the upper Senonian of West-

phalia at Hópingen, three and one half miles west of Münster.

They compare it to Myrica dryandrefolia Brong. (Comptonia

schrankii) and consider the resemblance to be very close. "They

also make comparisons with Dryandra cretacea Velen., which they

think is identical with Dryandra brongniarti Ettings. from Häring,

both of which species they would refer to the genus Comptonia.

The venation of Comptonia tenera is not shown in the speci-

502 THE AMERICAN NATURALIST [Vor. XL

mens figured but there can be no doubt of its being a Comptonia.

A large number of the smaller leaves of the existing species are

counterparts of these Senonian forms, the most similar figured

specimen being the leaf shown on PI. 2, Fig. 1

This species differs decidedly from Dryandra cretacea Velen.,

which I would retain in the Proteacez, otherwise the authors com-

parisons are most fortunate and it is very probable that we

have in Comptonia tenera the Cretaceous ancestor of Comptonia.

schrankii which is so common from the Eocene through the Mio-

cene.

Comptonia dryandroides Unger

Comptonia dryandroides Unger, Foss. Fl. v. Sotzka, p. 31 (161), pl.

6(27), fig. 1, 1850.

Andrà, Jahrb. k. k. geol. Anst., vol. 5, p. 562, 1854.

A E ungeri Ettings., Proteac. d. Vorwelt, p. 30 (738), pl. 4, fig. 1,

epu Foss. Fl. v. Kumi, vol. 35 (59), pl. 9, fig. 16-18, 1867.

Myrica (Comptonia) expen LI Acta Acad. Sci. Slav. Merid.,

vol. 1, p. 31, pl. 18, fig. 18, 1

Campione naumanni a a Abhandl. D. & K., vol. 4, p. 8,

pl. 2, fig. 2, 1888.

Myrica (Comptonia) cuspidata (Lesq.) Dawson, Trans. Roy. Soc. Can.,

vol. 8, sec. 4, p. 80, fig. 9, 1890.

A large-leaved and beautiful species of which Unger has figured

a perfect leaf from Sotzka, which is identical with, but somewhat

larger than Nathorst’s Comptoniphyllum naumanni from Japan.

These leaves are practically the counterparts of numerous leaves.

of the existing species (cf. Pl. 2, Figs. 3, 4). Those which are

described by Unger from Kumi have a prolonged base, which the

other included leaves lack. This is, however, a variable feature,

often present, though in a somewhat less degree, in the existing

species. Ettingshausen refers these leaves to Dryandra making

comparisons with Dryandra armata R. Br. of the existing flora.

His comparison is not, however, particularly fortunate as the latter

species has leaves which incline to a runcinate form, while the basal

portion of the leaf is much more narrowly lobed, some of the lobes.

being several times longer than they are wide and separated by an

No. 475] REVISION OF COMPTONIA 503

interval of midrib. I altogether fail to see any but the’most general

resemblances.

With regard to the relations of Comptonia dryandroides to the

other fossil species of Comptonia the following points may be men-

tioned.

The lobes are of the form of schrankii but much larger and the

leaves as a whole are comparatively less elongated. ‘There is

somewhat of a resemblance to the typical acutiloba leaves but the

size is greater and the lobes are longer and incurved. ‘The leaves

of eningensis have similar lobes when they are deeply lobed, but

the leaf as a whole is smaller and the incisions never seem to reach

the midrib as they do in dryandroides. Heer’s aventica (vindo-

bonensis) is intermediate in form between this species and enin-

gensis. Ludwig’s incisa also includes very similar leaves which

have, however, narrower, less incurved, and more rectangularly

placed lobes. Whether this species spread from Greece to Japan

or from Japan to Greece via southern Asia is problematical, but it

was probably more plentiful throughout parts of southern Asia

and on the hills of the incipient Himalayas than the fossils indicate.

The leaf from British Columbia which Dawson referred to Comp-

tonia cuspidata Lesq. differs from that species in size and in the

shape of the lobes. It is somewhat smaller than Unger’s type

material of dryandroides but is identical with the Japanese leaf

referred here. Dawson says (p. 81): “Allied with eningensis

Heer, obtusiloba Brongn., and dryandroides Ung. all of which may

be varieties of one species." To wningensis I fail to see any

resemblance except in the tip which is a variable character of little

weight. What Dawson means by obtusiloba Brongn. I have not

been able to make out.

Comptonia cuspidata Lesq.

Comptonia cuspidata Lesq., Proc. U. S. Nat. Mus., vol. 5, p. 445, pl. 6,

fig. 10-12, 1883.

Myrica (Comptonia) cuspidata (Lesq.) Knowlton, Proc. U. S. Nat

Mus., vol. 17, p. 221, 1894; Ann. Rep. U. S. Geol. Surv., vol. 17, pi.

hp. 885, 1896 (non Dawson).

This must have been a particularly beautiful plant with its large,

almost falcately lobed leaves. That these acute, upwardly directed

504 THE AMERICAN NATURALIST [Vor. XL

lobes are not anomalies is indicated by the three leaves that Lesque-

reux figures, which are of widely different sizes, his larger figure

indicating a leaf about fifteen centimeters in length and MAE

perfectly the characteristic venation of this genus.

Lesquereux compares this species with Comptonia acutiloba

Brongn., to which, however, the resemblance is not especially close,

not so close as it is, for instance, to Ludwig's larger figure of Comp-

tonia incisa (gaudinii Heer). In both of these species, however,

the lobes are laterally pointed and not ascending. ‘The European

leaf which is the closest to euspidata is Unger's specimen of dryan-

droides from the Oligocene of Styria, in which the resemblance

is quite striking although the lobes of the latter are somewhat less

ascending.

The occurrence of Comptonia cuspidata and premissa in Alaska

during the early Tertiary would seem to indicate that they represent

the invasion of the genus into Asia from the Arctica-North America

region which probably shortly preceded or followed this Alaskan

occurrence, as they are not so different from the two forms which

occur in the Miocene of Japan as to preclude the idea of their

standing in ancestral relations to the latter.

Comptonia premissa Lesq.

Comptonia p emissa Lesq., Proc. U. S. Nat. Mus., vol. 5, p. 445, pl. 6,

fig. 13, 1883.

Myrica (Comptonia) premissa (Lesq.) Knowlton, Ibid., vol. 17, p. 222,

1894; Ann. Rep. U. S. Geol. Surv., vol. 17, pt. 1, p. 885, 1896.

This lower Tertiary species from Coal Harbor and Chignik Bay,

Alaska, had leaves very similar to the younger leaves of the living

species of Comptonia and not especially close to any of its known

European contemporaries. Were the remains of Heer's laharpii

more definite it might possibly be compared with the Alaskan

form, while Sternberg’s type figure (Fl. d. Vorwelt, Pl. 24, Fig. 1)

of Comptonia diforme shows the closest resemblance to it of any of

the forms known to me.

. Comptonia gracillima (Heer) Berry

Dryandra gracilis Heer, Fl. Tert. Helv., vol. 3, p. 311 (note), 1859.

Myrica gracillima (Heer) Schimp., Pal. Végét., vol. 2; p. 559, 1872.

No. 475) REVISION OF COMPTONIA 505

?Myrica minima Sap., Etudes, vol. 1, p. 199, 1863.

Schimp., loc. cit., p. 562.

?Myrica pusilla Sap., loc. cit.

Schimp., loc. cit., p. 561.

Heer’s species was from the Oligocene of Spechbach in Alsatia

while Saporta’s were both from the Oligocene of Saint Zacharie

in France. These three species, so called, are all from strata of

about the same age, and not widely removed geographically, none

are figured by their authors, they are all founded on very small

obtusely lobed leaves, and while they may represent one or more

valid species of small size, it seems more probable that they are

founded upon immature leaves such as are so common on ter-

minal shoots in close proximity to the fruit in the modern species,

of one of the dominant Oligocene species, Comptonia schrankii for

instance.

I have united them provisionally under Heer’s name, which has:

priority, since if left as distinct forms they indicate an abundance

and variety of species of Comptonia which is apt to be very mis-

leading when based upon such insufficient evidence.

Comptonia grandifolia Unger

Comptonia grandifolia Unger, Chlor. Protog. (inedit.); Synopsis, p..

213, 1845; Gen. et Sp., p. 394, 1850; Foss. Fl. v. Sotzka, p. 31 (161),.

pl. 8 (29), fig. 1, 1850; Foss. Fl. v. Radoboj, p. 161, 1869.

Brongn., Tabl. p. 118, 1849.

Dryandroides een Ettings., Proteac. d. Vorwelt, p. 34 (742),

pl. 5, fig. 2, 1

This species is founded upon rather poor and indefinite remains.

of a gigantic leaf with obsolete secondary venation from the lower

Miocene (Mayencian) of Radoboj in Croatia. The specimen is.

5.5 em. wide across the more perfect lobes, while the largest leaf of

the existing Comptonia which I have been able to find is 3.5 cm.

wide, or seven elevenths of the size of the Radoboj leaf. Large-

leaved fossil Comptonias of undoubted authenticity are magnifica

of Watelet which is 3.2 em. wide, and matheroniana of Saporta

which is 3.8 em. in width. Comptonia grandifolia is almost iden-

tical in size and outline with the leaves of the existing Banksia

506 THE AMERICAN NATURALIST [Voi XL

grandis Willd. as pointed out by Ettingshausen (loc. cit.) so that

its reference to Comptonia may be regarded as largely proble-

matical.

Comptonia suessionensis Watelet

Comptonia suessionensis Wat., Pl. Foss. Bass. d. Paris, p. 122, pl. 33,

fig. 2, 1866.

Myrica suessionensis (Wat.) Schimp., Pal. Végét., vol. 2, p. 553, 1872.

A rather large leaf, exceptionally broad considering its narrow

lobes, somewhat similar to the leaf of the existing species shown

on Pl. 2, Fig. 2. Watelet’s figure shows us a curious combination

of rounded and acute lobes, and it seems quite probable that his

specimen is not correctly depicted. Schimper (loc. cit.) says that

this species greatly resembles Myrica dryandrejolia Brongn.

(Comptonia schrankii) but I fail to detect any very close resem-

blance.

With considerable doubt regarding the propriety of retaining

this as a valid species, I still see no other disposition to make of it

at present.

Comptonia laciniata Unger

Comptonia laciniata Unger, Gen. et Sp., p. 394, 1850; Foss. Fl. v.

Parschlug, p. 35, 1848; Foss. Fl. v. Sotzka, p. 31, pl. 8, fig. 2, 1850;

Iconogr., p. 33, pl. 16, fig. 8, 1852 (aments); Foss. Fl. v. Radoboj,

p. 161, 1869; Fl. Tert. Asia Mineur in Tschitacheff, Asia Min., pt. 4,

p. 320, 1869.

Brongn., Tabl., p. 121, 1849.

Dryandroides s dopintatics Ettings., Proteac. d. Vorw., p. 33, 1851.

Myrica ungeri Heer, Fl. Tert. Helv., vol. 2, p. 35, oh 70, fig. 7, 8, 1856.

Ibid., vol. 3, p. 176, pl. 150, fig. 29 (fruit)?, 1859 (non fig. 21, which

is referable to vindobonensis).

Massal., Pianti. Terz. Vicentino, pp. 243, 258, 1851.

Schimp., Pal. Veget., vol. 2, p. 556, 1872; Atlas, pl. 85, fig. 8, 1874.

Lesq., Proc. U. S. Nat. Mus., vol. 11, p. 27, 1888.

Boulay, “Fl. Foss. Gergov.”, Ann. Sei. Brux., 1899, pp. 59, 131.

ca Ludw., Paleont., vol. 8, p- 95, pl. 29, fie. 2, 2a; pl. 30, fig. 2, 3,

aci pm Heer, Fl. Tert. Helv., vol. 3, p. 176, pl. 150, fig. 19, 1859

(non fig. 20 which is referable to ine

No. 475] REVISION OF COMPTONIA 507

This is a beautiful species with large leaves some fifteen centi-

meters in length and upwards of three centimeters in width, irregu-

larly lobed; each lobe with one or more serrations of the margin

besides the rather larger, somewhat falcate, usually pointed tip.

There is considerable variation in the depth of the sinuses, Unger’s

type figure from Sotzka showing a leaf with deep sharp sinuses,

while the handsome specimen figured: by Heer (loc. cit., Pl. 70,

Fig. 7) has more shallow and slightly rounded sinuses. ‘The sharp-

ness of the serrations and tips of the lobes tends to be much softened

in the basal and apical portions of the leaves, in fact one of the

leaves figured by Heer has them distinctly rounded.

As remarked under Comptonia vindobonensis, some of the leaves

of that species are quite close to this one and are also represented

by variations of the modern leaf, an example of which is figured

on Pl. 2, Fig. 5. The latter, while shorter and not exactly similar to

laciniata, has precisely the same character of serrated lobes.

Unger observed in the collections from Parschlug, Styria, a stam-

inate inflorescence which he says is indistinguishable from that of

the existing Comptonia and which he refers to laciniata.

This species appears in some numbers in the late Oligocene

of the upper Rhone and Jura regions of central Europe and con-

tinues into the Upper Miocene (Tortonian) of Styria. It has

been recorded by Lesquereux from Spanish Peak, California, but

was not figured and I have been unable to locate the material upon

which his determination rests, so that this occurrence may be con-

sidered very doubtful for the reason that undoubted Myrica spe-

cies have leaves which are not very different from /aciniata. This

is especially to be seen in the leaves from Florissant, Col., and

Wycliffe, Ky., which Lesquereux named Myrica copeana, regarding

which I found it impossible to reach a decision until after con-

sulting the type material in the U. S. National Museum.

Comptonia matheroniana (Sap.) Berry

Myrica (Comptonia) matheroniana Sap., Etudes, vol. 2, p. 93, pl. 5,

fig. 7, 1865.

Schimp., Pal. Végét., vol. 2, p. 555, 1872; vol. 3, p. 691; Atlas, pl.

55, fig. 10, 1874.

508 THE AMERICAN NATURALIST Vor: XL

Boulay, Fl. Foss. Gergov., p. 73, 1899.

Probst, Jahresb. vaterl. Naturk. Würtemberg, p. 190, 1883.

Comptonia magnifica Watelet, Pl. Foss. Bass. Paris, p. 123, pl. 33, fig. 3,

1866

Myrica magnifica (Wat.) Schimp., loc. cit., vol. 2, p. 554, 1872.

Leaves of extremely large size with lobes similar to the normal

lobes in the leaves of the existing species. Saporta’s leaf is only

slightly larger, however, than the modern leaf shown in PI. 2,

Fig. 6.

The Eocene and Oligocene forms are very similar, what little

differences are apparent being probably due to the careless drawing

of the leaves from the Paris basin. Saporta’s figure, however,

does show a few serrations on some of the lower lobes which are

wanting in its Eocene ancestor, if we may draw such a conclusion

from the small amount of material available for study. I was at

first inclined to keep these two leaves separate, appearing as they

do at such different horizons, but there are a number of other iden-

tical species from the two horizons, and others with even a greater

range in the Cenozoic, so that it has seemed best to unite them as

above indicated. It is, of course, within the range of possibility that

they do not constitute a valid species but in each case are simply

abnormally large leaves of contemporary and smaller-leaved forms;

for instance, Watelet’s leaf might be merely a giant leaf of the

Belleu species which he named triangulata (gaudinii Heer).

Schimper notes the resemblance of these leaves to such Pro-

teaceous forms as those of Banksia grandis and repens of Robert

Brown, but the resemblance is much closer to the large leaves of

the modern Comptonia. Saporta in his revision of the Aix flora

records this species from that locality and notes its resemblance to

Myrica aculeata.

Comptonia microphylla (Heer) Berry

Myrica (Comptonia) parvula Heer, Fl. Foss. Arct., vol. 7, p. 20, pl. 55,

fig. 1-3, 1883.

Newberry, Fl. Amboy Clays, p. 63, pl. 19, fig. 6, 1896.

Myrica (Comptonia) parvifolia Heer, loc. cit., p. 77, pl. 71, fig. 12, 1883.

Rhus microphylla Heer, loc. cit., vol. 3, pt. 2, p. 117, pl. 32, fig. 18, 1874.

No. 475] REVISION OF COMPTONIA 509

It is difficult to understand upon what ground Heer founds his

two species parvula and parvifolia unless it is because they are

from different horizons. He compares both to the European

Myrica eningensis (Braun) Heer, although their resemblance to

that species, as a matter of fact, is not very close.

The two are exactly similar except that the form parvifolia is

somewhat the larger. ‘The Raritan leaf which Newberry refers

to parvula is more like parvifolia, which fact is noted by the latter

author, who, I suppose, hesitated about referring a Cretaceous leaf

to a species of the late Miocene as these Arctic deposits were

thought to be at that time.

I can see no reason for maintaining them as separate species,

even though one is Cretaceous and the other Tertiary, a statement

not altogether beyond question in view of the fact that labels are

sometimes misplaced, and in the case of parvifolia the name was

based upon a single imperfect specimen: which might readily enough

become included with other collections from earlier strata, both

having been collected by Professor Steenstrup's expedition. In

addition to the above, it may be remarked that the exact age of

the Greenland Tertiary deposits has never been definitely and

satisfactorily settled, and in all probability the Atanekerdluk

deposits are not younger than the Oligocene and more probably

are upper Eocene.

The first five or six leaves on young plants of the existing Comp-

tonia peregrina (Linn.) Coulter usually closely resemble this fossil

species both in size and in shape. "This is well shown by a com-

parison of the figures which I have reproduced; in fact the existing

leaves were they to occur as fossils would unhesitatingly be referred

to parvula Heer, some of them being exact duplicates of this fossil

leaf. Heer's Fig. 1 which shows a more primitive leaf than his

other figures, finds its counterpart in the first leaf of the modern

seedling, which is almost equally close to the types of Comptonia

microphylla and antiqua. I have collected a large number of leaves

of this form, and find this type with more or less accentuation to be

present in all the seedlings which I have examined.

We might consider these fossil leaves to be merely the abbreviated

leaves which are so common in seedling plants and hence without

phylogenetie meaning, or we might consider that this form of fossil

510 THE AMERICAN NATURALIST [Vor. XL

leaf represented the normal leaves of ancient Comptonia plants.

The former view seems to me doubtful, not only because of the

perishable nature of seedling leaves in general, but because it is

unusual for them to become detached and fossilized. ‘That they

are sometimes found as fossils is proven by the leaves from the

Swiss Tertiary which Heer calls Myrica latiloba (Fl. Tert. Hel.,

vol. 3, p. 176, pl. 150, figs. 12-15, 1859). Furthermore no other

species of Comptonia has been found in the Raritan clays or

Patoot schists from which they could have been derived. We are

quite justified in concluding that these leaves are the normal leaves

of the earliest known Comptonias and that the modern seedling

leaves are truly atavistic. From the abundance of the genus

Myrica with nine species in the Raritan, we may assume that the

Comptonia stock became separated from Myrica some time dur-

ing the lower Cretaceous, probably toward its close. While the

leaf which Heer calls Rhus is probably from a slightly higher hori-

zon than the Raritan leaf, its smaller size and its occurrence near

what was probably the original center of radiation of the genus

Comptonia, stamp it as the real starting point for any scheme of

Comptonia phylogeny and distribution, and also emphasize the

close relation, if not actual identity, between these forms of the

New World and Comptonia .antiqua Nilss. of Europe.

There are four species of Myrica in the Atane flora and two in

that of Patoot; one of the latter (praecox) Heer considers as referable

to Comptonia. While I do not agree in this reference, the species

in question might be considered as showing the close relation

between Myrica and Comptonia at this time, although I am strongly

inclined to think that Myrica praecox is a Quercus, to which genus

all of the early Comptonias show a passing resemblance, partic-

ularly the Raritan leaf.

Comptonia eningensis Al. Br.

Comptonia eningensis Al. Br., Neues Jahrb. f]. Miner., p. 108, 1845;

Verz. foss. Pfl. v. (Eningen, p. 76, 1851.

Unger, Gen. et. Sp., p. 394, 1850; Foss. Fl. v. Sotzka, p. 32 (162),

pl. 8 (29), fig. 3, 1850.

Brongn., Tabl., p. 121, 1849.

Massal., Pianti Terz. Vicent., p. 243, 1851.

No. 475] REVISION OF COMPTONIA 511

Dryandra eningensis Ettings., Proteac. d. Vorw., p. 28, 1851.

Myrica amm (Al. Br.) Heer, Fl. Tert. His, vol. 2, p. 33, pl. 70,

fig. 1 856; Ibid., a 3, p. 175, pl. 150, ít 18, 1859.

Bob. Pal. Végét., Fo; 2, p. 557, 1872; Atlas, pl. 85, fig. 9, 187

Comptonia meneghinii Unger, Foss. Fl. v. Sotzka, p. 32 (162), pl. 8 (29),

fig. 10, 1850.

Massal., loc. cit., pp. 47, 243

Dryandra meneghinii Ettings., loc. cit., p. 28.

M yrica meneghinii (Unger) Schimp., loc. eit., p. 555.

Schimper was the first to notice the resemblance of Unger's

Comptonia meneghinii ‘to Comptonia eningensis, a resemblance

so close that I have been constrained to consider the two forms

identical, an additional reason for this treatment being the unim-

portance of the remains of the former. Ettingshausen refers

both forms to Dryandra, comparing the former with Dryandra

obtusa and plumosa of Robert Brown and the latter with the same

author's Dryandra floribunda and cuneata. It may be noted

that their texture is much more membranaceous than obtains in

the genus Dryandra. The species may be defined as including

medium and rather small leaves of the general proportions of

the modern leaf, with triangular, ascending, pointed, obtuse-

tipped lobes. Incisions reaching only part way to the midrib.

Base cuneate, more produced than in any specimens of the mod-

ern leaf that I have seen. The apex is also produced and shows

but incipient indications of lobation.

These leaves approach very near to Comptonia vindobonensis,

particularly to the Swiss leaves of that species, with which they

are almost identical.

Comptonia obtusiloba Heer

M yrica nn obtusiloba Heer, Uebers. Tertiarfl. d. Schw., p. 52,

1854; t. Helv., vol. 2, p. 35, pl. 70, fig. 10, 1856.

Reporte, nars vol. 3, p. 105, pl. 5, fig. 7, 1865.

Schimp., Pal. Végét., vol. 2, p. 560, 1872

Ettings., Blattskel. Dikot., p. 3.

Boulay, “ Fl. foss. Gergov.," Ann. Sci. Brux., vol. 23, p. 59, 1899.

Myrica laharpii Heer, Fl. Tert. Helv., vol. 2, p. 34, pl. 70, fig. 11, 12

1856.

Schimp., loc. cit., p. 559.

512 THE AMERICAN NATURALIST [Vor. XL

Myrica rotundiloba Sap., loc. cit., vol. 1, p. 200; vol. 2, p. 46, pl. 5, fig. 3,

Schimp., loc. cit., p. 554.

Includes leaves with poorly developed, rather irregularly

rounded lobes, Saporta’s specimen from St. Zacharie showing

a few remote serrations. Both the form known as rotundiloba

Sap., and laharpii Heer apparently represent anomalous leaves,

the former occurring only as a single fragment and the latter

consisting of very imperfect material which Heer says is similar

to various Proteaceous leaves except for the thin midrib. The

type material of obtusiloba is considered by Heer to be very sim-

ilar to the Sotzka leaves of acutiloba, but I fail to see such a

resemblance. The laharpii form is very similar in outline to

Watelet's Comptonia pedunculata from the French Eocene, and

Saporta notes the close similarity between his rotundiloba and

Heer's laharpii.

The various remains which I have included in this species are

all somewhat indefinite in form and venation, and without uniform-

ity in lobal characters, so that they shed but little light upon the

relations of the plants which bore them, to the other species of

Comptonia.

Comptonia partita (Lesq.) Berry

Myrica partita Lesq., Ann. Rep. U. S. Geol. Surv. Terr. for 1873, p.

412, 1874; Tert. Fl., p. 134, pl. 17, fig. 14, 1878.

This subcoriaceous fragment, consisting of but two lobes on

each side, was collected by Professor Cope from the Eocene of

Nevada. Lesquereux compares it with aningensis of Braun, and,

except for the margin, which was denticulate on the lower border

of the lobes, with incisa of Ludwig. It is entirely indefinite in

character and simply serves to show that there was in the Ameri-

can Eocene, a Comptonia species with leaves of the same general

type as the species gaudinii Heer, dryandroides Unger, and

diforme Sternb., which are so common in the European Ter-

tiary. The Miocene of British Columbia furnished Dawson

with a leaf that he called Comptonia columbiana which is almost

No. 475] REVISION OF COMPTONIA 513

identical with partita although I prefer to consider it more closely

- related to diforme. ‘The occurrence of the latter in the late Ter-

tiary in connection with the occurrence of partita in the early

Tertiary renders it almost certain that Comptonia was better

represented and with more widely ranging species in the Ameri-

can ‘Tertiary that the fossil remains hitherto found would indi-

cate, and this is just what we would anticipate from the Euro-

pean evidence.

Comptonia pedunculata Watelet

Comptonia pedunculata Watelet, Pl. Foss. Bass. Paris, p. 124, pl. 33,

fig. 5, 6, 1866.

Myrica pedunculata Schimp., Pal. Végét., vol. 2, p. 555, 1872.

Comptonia rotundata Watelet, loc. cit., fig. 7.

Friedrich, “ Beitr. z. Kennt. Tertfl. Sachsen,” Abh. geol. Spk. Preuss.

u. Thüring., vol. 4, p. 221, pl. 29, figs. 15, 15a, 1883.

All of Watelet’s figures in the work cited above have the appear-

ance, both in the venation and outline depicted, of having had the

testimony of the specimens largely supplemented by the imagina-

tion of the artist. Especially is this true of the leaves which he

calls Comptonia pedunculata and Comptonia rotundata. However,

we cannot but consider these two forms when combined, to be

entitled to specific rank especially as similar leaves have come to

light in the lower Oligocene of Saxony, Watelet’s types coming `

from the Eocene (Sables de Bracheux) of Belleu, France. The

species is well named pedunculata, as Watelet’s Fig. 6 has the

longest petiole of any Comptonia leaf that I have ever seen, it

being several times the length of the petioles in the existing species.

Examples of leaves of the latter that greatly resemble the fossil

species in outline, are often found among the larger leaves. While

the fossil leaves apparently show rounded lobes with but slight

incisions, it is probable that the rather full lobes overlapped as

they do in so many leaves of the modern species, and that in

reality the lobes were distinct as they were in the latter.

In its rounded margins pedunculata approaches laharpii Heer

(obtusiloba) although I think that this is only an apparent simi-

larity. Reasoning from the rur furnished by the abundant

514 THE AMERICAN NATURALIST [Vor. XL

rounded-lobed leaves of the existing species it would be a reasonable

conclusion that pedunculata is simply a round-lobed form of some.

of its normally lobed contemporaries, which one, of course, it

is impossible to say, but not necessarily the same species in the

Oligocene as in the Eocene.

Comptonia schrankii (Sternb.) Berry

Aspleniopteris schrankii Sternb., Fl. Vorwelt, vol. 2, p. 29, pl. 21, fig. 2,

1822; vol. 4, p. 22, 1825.

Colston ? dryandrejolia Brongn., Ann. Sci. Nat., ser. 1, vol. 15, p.

49, pl. 3, fig. 7, 1828 (Schimper, Pal. Végét., vol. 2, p. 808, erroneously

cites vol. 4); Prodrome, pp. 143, 214, 1828; Tabl., p. 118, 1849.

Unger, Synopsis, p. 213, 1845; Gen. et Sp., p. 393, 1850

Squinabol., Cont. Fl. Foss. Terz. Liguria, pt. 4, p. 17, 1892.

Massal, Sopra Pianti Foss. Terr. Terz. Vicentino, pp. 243, 258, 1851.

Myrica (Comptonia) dryandrejolia Saporta, Etudes, vol. 2, p. 104, pl.

5, fig. 8, 1865 (reproduced in Schimp., Pal. Végét., pl. 85, fig. 19-21).

Dryandra schrankii Ettings., Proteac. d. Vorw., p. 26, pl. 3, fig. 1-8,

1851; Fl. v. Häring, p. 55, pl. 19, fig. 1-26, 1853; Foss. Fl. Monte

Promina, p. 34, pl. 14, fig. 5, 6, 1855.

Web. & Wess., Paleont., vol. 4, p. Ja RS pl. 25 (6), fig. 12, 1856.

Myrica brongniarti (Ettings.) Lesq., Ann. Rep. U. S. Geol. & Geog. Surv.

Terr., jor 1873, p. 412, 1874; puse: Flora, p. 135, pl. 17, fig. 15,

1878.

Comptonia breviloba Brongn., in Sedg. & Murch., Trans. Geol. Soc. Lond.,

ser. 11, vol. 3, p. 373, 1832; Tabl., p. 118, 1849.

ile Synopsis, pp. 213, 305, 1845; Gen. et Sp., p. 349, 1850; Foss.

Fl. v. Sotzka, p. 32, pl. 8, fig. 9, 1850.

Comptonites dryandrefolius Göpp. in Bronn, Ind. Paleont., vol. 1, p.

22, 1848; vol. 2, p. 45, 1849.

Leaves of this species were described and figured by Sternberg

as early as 1822. He thought that he was dealing with a fern

and used the generic name Aspleniopteris. With the exception of

the somewhat doubtful specimen from the Green River group

(Eocene) which Lesquereux refers to Myrica brongniarti, the

species is confined to Europe, where it is quite common and ex-

tends from the Eocene of the Isle of Wight up through the Mio-

cene, becoming especially common and widespread during the Oli-

gocene and Miocene. I have shown on PI. 2, Fig. 1, a leaf of the

existing species which is very close to this species, particularly

No. 475 REVISION OF COMPTONIA 515

to that size and form of leaf figured by Brongniart. Both Ettings-

hausen and Heer, partially followed by Schimper, consider the

leaves referred to the various species in the foregoing synonymy,

as identical and they compare them with the leaves of the living

Dryandra formosa R. Br. They exclude them from Comptonia

because of their thick midrib, acute lobes, and coriaceous texture,

exactly the characters in numerous instances of the young leaves

near the growing tips in the existing Comptonia. I do not think

that there can be any doubt regarding the identity of these fossil

forms and I fail to see any characters which weigh against their

reference to Comptonia unless it be their comparatively greater

length. Some of the forms are characteristically those of Comp-

tonia, e. g., some of the leaves from Monte Promina and Hiring,

which also form a transition series toward Comptonia diforme; and

these leaves gradually vary to the slender and acutely lobed forms.

If comparisons are made with a large enough series of leaves of

the existing species, many resemblances will at once become

apparent, especially as remarked, to the slender, coriaceous,

thick-veined leaves of the tips of shoots. The latter are not

usually acutely lobed but often have that appearance in leaves

not completely unfolded, or in herbarium specimens in which the

lobes have become somewhat involuted in drying, as they usually

do. In this condition they are indistinguishable from the fossil

specimens. The American leaf of Lesquereux which is included

in this species is less incised than the foreign forms and has

rounded lobes. It is connected with the more typical leaves by

the form described by Web. & Wess. from Rhenish Prussia.

Engelhardt in his “ Tertiärflora Jesuitengrabens bei Kundratitz

in Nordböhmen ”! figures what he considers catkins of Myrica.

His figures look much more like leaves of this species, however,

than they do like catkins.

Comptonia vindobonensis (Ettings.) Berry

Dryandra vindobonensis Ettings., Tert. Fl. v. Wien, p. 18, pl. 3, fig. 6,

1851.

Dryandroides coneinna Heer, Fl. Tert. Helv., vol. 3, p. 188, pl. 153, fig.

8-10, 1859.

1 Nova Acta Leop. Carol., vol. 48, no. 3, pl. 8, fig. 10, 11, 1885.

516 THE AMERICAN NATURALIST [Vor. XL

Dryandroides bituminosa Sap., Exam. Anal. Fl. Tert. Provence, p. 22,

1861.

Dryandra aventica Heer, loc. cit., p. 186, pl. 153, fig. 17.

Dryandra Rolleana Heer, Ibid., (footnote), pl. 153, fig. 18.

Myricophyllum bituminosum Sap., Etudes, vol. 1, p. 221, pl. 8, fig. 1,

1863.

Myrica (Comptonia) vindobonensis Heer, loc. cit., vol. 2, p. 34, pl. 70,

fig. 5, 6, 1856.

Myrica vindobonensis (Ettings.) Heer, loc. cit., vol. 3, p. 176, pl. 150,

fig. 16, 17, 1859; Fl. Foss. Arct., vol. 2, pt. 2, p. 27, pl. 3, fig. 4, 5,

1869; Mioc. Baltic FL., p. 32, pl. 7, fig. 4-10, 1869.

Ludwig, Paleont., vol. 8, p. 94, pl. 28, fig. 6, 7, 1860.

Unger, Foss. Fl. v. Kumi, p. 22, pl. 4, fig. 20-30, 1867.

Schimp., Pal. Végét., vol. 2, p. 558, 1872; Atlas, pl. 85, fig. 1, 2, 1874.

Knowlt., Proc. U. S. Nat. Mus., vol. 17, p. 222, 1894; Ann. Rep.

U.S. Geol. Surv., vol. 17, pt. 1, p. 885, 1896.

Engelh., Tertfl. Jésustenarab. Kund. in Nordböhm., p. 19, pl. 1, fig. 40,

1885; Verh. k. k. geol. Reichsanstalt, no. 5, p. 2,

Myrica Græffii Heer, loc. cit., pl. 150, fig. 20, (non fig. 19 which is refer-

able to Comptonia lacitiuia).

Myrica ungeri Heer, loc. cit., p. 176, pl. 150, fig. 21 (non fig. 22), 1859.

Ludwig, loc. cit., p. 95, pl. 29, fig. 2, 2a; pl. 30, fig. 2, 3, 1860.

M yrica denticulala Ettings., Foss. Fl. v. Koflach, p. 12, pl. 1, fig. 7,1857.

This species approaches Comptonia laciniata quite closely in

Unger’s leaves from the Grecian Oligocene, which also closely

resemble that style of leaf of the modern species shown on Pl. 2, Fig.

5, a type which is not at all rare on certain of the modern plants of

‘Comptonia.

One of the figured leaves which Heer calls Myrica greffii is refer-

able to vindobonensis and the other to laciniata, which shows how

closely these two species are related. In the other direction vin-

dobonensis approaches quite near to eningensis, such leaves for

instance as those of Heer from Switzerland and those of Ettings-

hausen from Koflach coming very near to the last-mentioned species.

As is suggested by its extensive synonymy Comptonia vindobonen-

sis as here understood, includes somewhat diverse forms, ranging

from the small Planera-like leaves from the Baltic region and the

Dryandra-like leaves from Switzerland (coneinna), through the

narrow, more elongated, and but slightly lobed leaves of the French

Oligocene (Saporta) and Austrian Miocene (Ettingshausen) to the

large-lobed leaves from Hesse which Ludwig referred to this species,

No. 475] REVISION OF COMPTONIA 517

and to those from Switzerland which Heer referred to rolleana and

aventica.

These variations while somewhat wide in their extremes include

numerous gradating forms and are not at all inconsistent with their

reference to a single species, especially when we consider the dura-

tion of this form from the Eocene through the Miocene, during

which time it spread all over Europe and possibly to America as

well.

518 THE AMERICAN NATURALIST [Vor. XL

| laciniata ceningensis diforme grandifolia

| \ dryandroides obtusiloba

8. ` ` EN

= | vindobonensis schrankii |

= 4 | | gaudinii

2: \ |

X | | |

| | |

| |

| | |

: | |

| \

qe | | | |

| laciniata ceningensis | \ dryandroides E

| | | obtusiloba

| vindobonensis | schrankii / : a

| \ | | diforme : gaudinii

2 | | j ; |

E | | / | |

d J gracillima / macroloba

e | / / : matheron-

S | | / | iana

I | / * i

> | | / | ; | |

| | Tj | pedunculata | |

| | / | |

1 /

| | | | |

ee Ee Tur | |

| partita vindobonensis | |

| | / i

| insignis | diforme macroloba

| premissa schrankii | / pedunculata

| | | | / 2

3 j euspidata- | | j d gaudinii |

S ! | | / /

m | | | / f FA matheroniana

r | qu Fo y

| | |j "d suessionensis

| | Py / 3

| m / 4 »

L | DEA

| | » vA

x | microphylla tenera ^ d

8-4

= |

u | :

GO | antiqua

Diagram showing the relationship of the leaves of the fossil species of Comp-

tonia, not necessarily the phylogeny of the plants which bore them.

No. 475] REVISION OF COMPTONIA 519

List OF CHANGES IN COMPTONIA NOMENCLATURE

Aspleniopteris difformis Sternb. <Comptonia diforme (Sternb.) Berry.

Aspleniopteris schrankii Sternb. <Comptonia schrankii (Sternb.) Berry.

Asplenium dijorme Sternb. <Comptonia dijorme (Sternb.) Berry.

Comptonia acutiloba Brongn. « Comptonia dijorme (Sternb.) Berry.

Comptonia asplenifolia Gaertn.— Comptonia peregrina (Linn.) Coulter.

Comptonia breviloba Brongn. <Comptonia schrankii (Sternb.) Berry.

Comptonia columbiana Daws. « Comptonia dijorme (Sternb.) Berry.

Comptonia concisa Wat.< Comptonia macroloba (Web. & Wess.) Berry.

Comptonia dryandrefolius Brongn. <Comptonia schrankii (Sternb.) Berry.

Comptonia incisa Ludw. <Comptonia gaudinii Heer.

Comptonia magnifica Wat. « Comptonia matheroniana (Sap.) Berry.

Comptonia meneghinii Ung. <Comptonia eningensis Al. Br.

Comptonia rotundata Wat. < Comptonia pedunculata Wat.

Comptonia triangulata Wat. <Comptonia gaudinii Heer.

Comptonia ulmijolia Ung. « Planera ungeri Ettings.

Comptonia vinayi Sap. < Comptonia diforme (Sternb.) Berry.

en japonicum Nath. <Comptonia gaudinii Heer.

Comptoniphyllum naumanni Nath. <Comptonia dryandroides Ung.

Co nb rhe antiquus Nilss.— Comptonia antiqua Nilss.

Comptonites dryandrejolius Gópp. < Comptonia schrankii (Sternb.) Berry.

Dryandra acutiloba (Brongn.) Ettings. <Comptonia dijorme (Sternb. )

err

Dryandra antique Ettings.— Comptonia antiqua Nilss.

Dryandra aventica Heer <Comptonia vindobonensis (Ettings.) Berry.

Dryandra brongniarti Ettings. <Comptonia schrankii (Sternb.) Berry.

Dryandra comptoniefolia Ettings. <Comptonia dijorme (Sternb.) Berry.

Dryandra gracilis Heer <Comptonia gracillima (Heer) Berry.

Dryandra macroloba Web. & Wess.— Comptonia macroloba (W. & W.)

Berry

Dryandra meneghinii Ettings. <Comptonia eningensis Al. Br.

Dryandra eningensis Ettings.— Comptonia eningensis Al. Br.

Dryandra rolleana Heer <Comptonia vindobonensis (Ettings.) Berry.

Dryandra saxonica Friedrich <Comptonia diforme (Sternb.) Berry.

Dryandra schrankii Heer <Comptonia schrankii (Sternb.) Berry.

Dryandra ungeri Ettings.— Comptonia dryandroides Ung.

Dryandra vindobonensis Ettings. <Comptonia vindobonensis (Ettings.)

Berry.

Dryandroides bituminosa Sap. <Comptonia vindobonensis (Ettings.) Berry.

à .

Liquidambar asplenijolia Linn.= Comptonia peregrina (Linn.) Coulter.

Liquidambar peregrina Linn.— Comptonia peregrina (Linn.) Coulter.

-Myrica (C.) acutiloba Brongn. <Comptonia dijorme (Sternb.) Berry.

520 THE AMERICAN NATURALIST [Vor. XL.

M yrica alkalina Lesq. <Comptonia insignis (Lesq.) Berry.

Myrica asplenifolia Linn.— Comptonia peregrina (Linn.) Coulter.

Myrica brongniarti (Ettings.) Lesq. <Comptonia schrankii (Sternb.) Berry.

Myrica concinna (Heer) Schimp. <Comptonia vindobonensis (Ettings.)

erry.

Myrica concisa (Wat.) Schimp. <Comptonia macroloba (W. & W.) Berry..

Myrica eredneri Engelh. <Comptonia gaudinii Heer.

Myrica (C.) cuspidata (Lesq.) Daws. (non Lesq. or Knowlton) <Comptonia

dryandroides Un

Myrica denticulata Ettings. <Comptonia vindobonensis (Ettings.) Berry.

Myrica (C.) dryandrefolia Sap. <Comptonia schrankii (Sternb.) Berry.

Myrica (C.) gaudinii Heer = Comptonia gaudinii Heer.

Myrica gracillima (Heer) Schimp. <Comptonia gracillima (Heer) Berry.

Myrica grandijolia (Ung.) Schimp.— Comptonia grandifolia Ung.

Myrica greffii Heer in part <Comptonia vindobonensis (Ettings.) Berry.

in part <Comptonia laciniata Ung

Myrica incisa (Ludw.) Schimp. <Comptonia gaudinii Heer.

Myrica insignis Lesq.— Comptonia insignis (Lesq.) Berry.

Myrica laharpii Heer < Comptonia obtusiloba Heer.

M yrica latiloba Heer— juvenile Comptonia leaves.

Myrica macroloba Web. & Wess.— Comptonia macroloba (W. & W.) Berry.

M yrica magnifica (Wat.) Schimp. <Comptonia matheroniana (Sap.) Berry.

Myrica (C.) matheroniana Sap.— Comptonia matheroniana (Sap.) Berry.

Myrica meneghinii Ung. < Comptonia eningensis Al. Br.

M yrica minima Sap. <Comptonia gracillima (Heer) Berry.

M yrica (C.) obtusiloba Heer — Comptonia obtusiloba Heer.

Berry

Myrica (C.) parvifolia Heer <Comptonia ipkut (Heer) Berry.

M yrica (C.) parvula Heer <Comptonia microphylla (Heer) iie

Myrica pedunculata Schimp.— Comptonia pedunculata Wat

Myrica (C.) premissa (Lesq.) Knowlton = Comptonia siint Lesq.

M yrica pusilla Sap. <Comptonia gracillima (Heer) Berry.

Myrica rotundiloba Sap. < Comptonia obtusiloba Heer.

yrica suessionensis (Wat.) Schimp.— Comptonia suessionensis Wat.

M yrica (C.) tschernowitziana Engelh. <Comptonia gaudinii Hee

M yrica ungeri Heer in part <Comptonia vindobonensis (Ettings.) Barty.

in part <Comptonia laciniata Ung.

M etn (C.) vindobonensis Heer <Comptonia vindobonensis (Ettings.)

Myricophyltam bituminosum Sap.<Comptonia vindobonensis (Ettings.)

Berry.

Phyllites antique Nilss.= Comptonia antiqua Nilss.

Pterophyllum difformis Gópp. <Comptonia schrankii (Sternb. ) Berry.

Rhus microphylla Heer < Comptonia microphylla (Heer) Berry.

Zamites difformis Presl. <Comptonia schrankii (Sternb.) Berry.

PLATE 1

(Figures somewhat enlarged)

Fiss. 1-3.— Compound leaves of Comptonia peregrina (Linn.) Coulter.

Figs. 4-7.— Basal leaf-lobes of Comptonia peregrina (Linn.) Coulter.

Figs. 8-12.— Stipules of Comptonia peregrina (Linn.) Coulter.

Ale

N IN NN

PLATE 2

Fıs. 1—6.— Leaf variations in Viewers peregrina (Linn.) Coulter for compari-

son with fossil species (all natural size).

ALT

: A m N

T NY

PLATE 3

—X and leaf variations among juvenile leaves of Comptonia peregrina (Linn.)

Coulter (all natural size).

PLATE 4

Fic. 1. Hee fter Heer, 1883, Pl. 55, Fig. 1-3.

Fic. MEE itudin iue Nilss, an ne. 1837, Pl. 34, Fig. 7.

Fig. 3.— Comptonia parvifolia Heer. After Heer, 1883, Pl. 71, Fig. 1, 2.

Fic. 4.— Complonia p arvula Heer. After Weba, 1896, Pl. 19, Fig. 6

NOTES AND LITERATURE

PALEONTOLOGY

Jordan’s Guide to the Study of Fishes.'— Without question this

is one of the most useful and reliable, as it is also the most compre-

hensive of general works consecrated to the class of fishes. Every

subject that is properly included within the domain of ichthyology,

whether from a purely scientific, historical, economical, or even Wal-

tonian standpoint,— in fact, all that pertains to fishes living and fossil,

— is awarded its place in this repository, and is treated in a manner

only possible for the expert of life-long experience. But for the ex-

ceptional qualifications of the author, a work of such magnitude and

intricacy of details could scarcely have resulted successfully without

the coöperation of numerous specialists; the mere labor of bringing

together the results of painstaking research during the last few years

implies a capacity often regarded as an attribute of genius. Surely

the author is to be congratulated upon having accomplished his task

so well, and students of ichthyology in general upon having at their

command a wealth of carefully analyzed and orderly arranged facts.

Although addressed primarily to students of the modern fauna,

this large compendium in two volumes takes ample account of fossil

orms. Several of the earlier groups are treated in separate chapters

at considerable length, and others are referred to constantly through-

out the work. In respect to primitive Devonian fishes, or fish-like

vertebrates, the latest contributions of Traquair, Dean, Patten, Regan,

and others are passed in review, with mention of newly discove

structural features, and discussion of latest proposed changes in classi-

fication. The chapter on Arthrodires is modeled largely after Dean’s

recent treatment of the group, hence their exclusion from Dipnoans,

a step that we are compelled to regard as retrogressive in view of all

the evidence now accumulated in favor of their union. It is also to

be regretted that new cuts have not been introduced to replace several

antiquated and misleading figures of Ostracophores, and even “ Ga-

noids.” Scientific text-books often remind us that the law of the

‘Jordan, D. S. A Guide to the Study of Fishes. New York, Henry Holt and

Co., 1905. 2 vols., 8vo.

525

526 THE AMERICAN NATURALIST [Vor. XL

survival of the fittest is apparently reversed in the case of poor illus-

trations. Figures of recent forms, however, in the work under dis-

cussion, are uniformly excellent. Those of the fossil forms that have

been washed over may appear more artistic, but certainly have not

lost their obscurity. The profusion of illustrations is gratifying

as it is remarkable; yet one would willingly spare some of them for

greater accuracy of detail in the rest.

No other general treatise on fishes, not even the most recent, can

compare with this as regards the fullness with which fossil representa-

tives are discussed in connection with the recent. This is as it should

be, and sets a praiseworthy example for other zoólogical writers to

emulate. When we have said that the treatment throughout betrays

the master hand, the character of the work and its authoritativeness

have been sufficiently indicated.

CHE

Lankester’s Extinct Animals.'— Under this title is collected in

book form, of convenient size and well illustrated, the series of paleon-

tological lectures delivered by the Director of the natural history

departments of the British Museum during the preceding winter.

Since the days of Buckland, Mantell, and Hugh Miller, the British

reading public has not lacked popular works for keeping in touch

with the progress of paleontological discovery, and for picturing

vividly before the imagination the life of bygone ages. Of late years

American readers have been even more liberally provided for, through

the medium of several first-class popular works, good, bad, and indif-

ferent magazine articles, and the too often absurd exploitations of the

Sunday press. Thus there has been no dearth of opportunity for

becoming acquainted, in a literary way at least, with creatures of other

days.

The new work displays a more rational treatment of the subject

than many of its predecessors, there is a more judicious selection and

arrangement of facts, and there is constant appeal to the reader to take

the bookin hand as one would his Baedekker or art museum catalogue,

in order to compare the things actually placed on exhibition with what

is said about them. This implies, of course, that the majority of

readers have access to large public collections; but for those who have

not this privilege, more than two hundred illustrations, mostly from

‘Lankester, E. R. Extinct Animals. New York, Henry Holt and Co., 1905.

8vo, 331 pp., 218 figs.

No. 475] " NOTES AND LITERATURE 021

photographs, are provided to supply the deficiency. One of the pur-

poses of these lectures, therefore, is to serve as a sort of museum guide;

but this is by no means all. Interwoven with the descriptions of fossil

forms is a great deal of explanatory matter which enables the lay

reader to gather, as he goes along, trustworthy information in regard

to geological phenomena, evolutionary history, the relations between

fossil and modern faunas, former conditions of life, and general trend

of animal development.

'The chapters on mammals and reptiles occupy the greater part of

the book, and attention is concentrated upon a limited number of

striking examples, illustrative of particular points, so that the con-

fused image resulting from discursive treatment is avoided. The

value of the work lies largely in its suggestiveness. A few facts,

clearly and sufficiently set forth, intensify the interest and stimulate

the quest of knowledge much more than a bewildering array in which

there is no visible bond of unity. Professor Lankester reveals to us

the beauty of the paleontological landscape by taking us leisurely

over some of its hills and dales, and leaves to us our own sense of per-

spective to fill in the details. There are one or two features, however,

that one could wish the author had dwelt upon a little more fully.

Many years ago he contributed an admirable monograph on the fishes

of the Old Red Sandstone, still a standard authority. We would have

liked him to tarry longer in referring to these forms anew. It is to be

regretted, also, that the splendid restoration of Diplodocus presented

to the British Museum during the year by Mr. Carnegie does not fig-

ure in this work, and that the actual skeleton of Triceratops is not

shown alongside of Mr. Knight's model. The long supra-occipital

crest of Pteranodon, a most striking feature, is unfortunately omitted

from the figures that are given of this genus. These, however, are

coinparatively trifling defects, and are more than offset by the general

excellence of illustrations, and conspicuous merit of the descriptive

matter.

C. R. E.

Notes.—- Dollo on Iguanodon. Professor Dollo’s researches on

Belgian fossil reptiles are well known, in particular those dealing with

the famous Dinosaurs of Bernissart. Some further considerations

are now offered (Dollo, L., “Les allures des Iguanodons, ” Bull.

Scient., vol. 40, 1905; “Les Dinosauriens adaptés à la vie quadru-

pède secondaire,” Bull. Soc. Belge Géol., vol. 19, pp. 441-448, 1905)

concerning the gait of these animals, and such skeletal modifications

528 THE AMERICAN NATURALIST [Vor. XL

as are affected by, or are coördinated with the manner of progres-

sion. In the first of these papers an attempt is made to classify

different series of footprints according as they were made by the ani-

mal in a resting posture, walking, or running; in the second, argu-

ments are advanced to show that certain Dinosaurs are primarily

quadrupedal in gait, others secondarily so, as the result of change

in function amongst forms which resembled Iguanodon in being

primarily bipedal. The arguments are based upon persistence

of adaptive characters, and illustrations are drawn from various

sources. Dollo’s interpretation of tracks suggests the importance of

tracing as extended series of footprints made by a single animal as we

can find record of in the Newark beds of the Connecticut Valley.

| C. R. E.

GEOLOGY

Ries's Economic Geology of the United States! is one of the

latest text-books on this phase of geology. It is a volume of 435

pages with numerous illustrations, published by the Macmillan

Company, in 1905. A novel feature of the volume is the treatment

of the non-metallic minerals before the metallic. If the reason for

this change — namely, that the most important should be considered

first — is justified, it seems strange that the pages devoted to soils

should be the very last in the non-metallic portion.

The space allotted to the various subjects is often disproportionate;

thus soils are dismissed in four pages, and all the building stones of

igneous origin, with the exception of the granites, are treated in four-

teen lines. |

"The plates are very good, but the method of display is not satis-

factory, as the pictures are not appropriately placed with respect to

the text that refers to them. It is also unfortunate that sometimes

two pictures of entirely unrelated features should be placed on the

same eg An example of this is Plate 25; 1, View of Bauxite

Bank, ete., 2, Furnace for Roasting Mercury Ores, etc. The proof-

reading has been well done, the omission of “n” in brownstone on

page 69 being practically the only error noted.

1 Ries, H. Economic Geology of the United States. New York, The Mac-

millan Co., 1905. 8vo, xxi + 435 pp., 25 pls., 97 text figs. $2

No. 475] NOTES AND LITERATURE 529

Several omissions and slight errors of statement, some of which

seem worthy of note are as follows. On page 39, it is stated that

until 1883 petroleum was used chiefly for medicinal purposes. This

seems rather an understatement of its uses, for, according to the

Census figures quoted by the author on page 62, over $26,000,000

worth of petroleum was produced in 1880. On page 111, puzzuolano

is described as though it was only an artificially prepared cement,

whereas the original material derived from Puzzuoli was natural

voleanic ash. The natural cements prepared from volcanic ash re-

ceive no notice in the classification used by Ries.

The list of the different clays is quite complete, but the absence of

“slip-clay” is noted. This is such an interesting and important

group of clays and its value is so largely determined by chemical

composition that it deserves some treatment. Another slight error

occurs on page 191, were it is stated that the main value of monazite

is for “the manufacture of mantles for incandescent lights "— the

word incandescent is inapplicable.

One point on which students differ with Professor Ries is the use

of the term “thermal” spring. He states that a thermal spring is

one whose temperature is 70° Fahrenheit or over (page 204). The

old definition, that a thermal spring is one whose temperature is 2° F.

above the mean annual temperature of the place of exit, seems in

many ways more desirable, for a spring in the tropies with a temper-

ature not higher than 70° F. ought not to be considered a thermal

spring, while a spring of 40° or 50° F. in high latitudes should be so

considered.

A valuable working bibliography is appended to each chapter, and

contains references to many of the latest publications.

P.5.8.

Notes.— The Geological Magazine for November and December

(decade 5, vol. 2, nos. 11 and 12) contains three articles of general

geologic interest. The first, in the November number, is by Professor

Jamieson on “Some Changes of Level in the Glacial Period," the

region under discussion being mainly Scotland and portions of Scan-

dinavia. The second article, in the December number, on “ The

Geological History of Victoria Falls," is by G. W. Lamplugh. "These

falls are particularly interesting on account of the peculiar zigzag

pattern of the canyon below the falls. In the December number is

also the final paper of Sir H. H. Howorth's article on “The Recent

Geological History of the Baltic."

530 THE AMERICAN NATURALIST (Vou. XL

Water Supply and Irrigation Paper 119, by J. C. Hoyt and B. D.

Wood, is an “Index to the Hydrographie Progress Reports of the

United States Geological Survey from 1888-1903.” This is a valuable

paper, as it brings together in one volume a bibliography of the papers

published by the Survey, which have heretofore not been satisfactorily

listed in the bibliographies.

Bulletin 7, Fourth Series, Geological Survey of Ohio, by Charles S.

Prosser, published in Columbus, November 1905, and entitled “Re-

vised Nomenclature of the Ohio Geological Formations,” is an im-

portant contribution to stratigraphy. It successfully presents the

results of much detailed study, and places the previously rather

loosely defined horizons in their proper positions. It shows not only

their relation to each other, but, in a broad way, correlates the forma-

tions with those outside the State. Bulletin 7, however, is only a pre-

liminary report, so that the final report is awaited with interest.

Two new maps of portions of Alaska are included in the report of

L. M. Prindle on “The Gold Placers of Fortymile, Birch Creek and

Fairbanks Regions, Alaska”— Bulletin 251, United States Geological

Survey. The report is based mainly on reconnaissance work, but

certain facts seem to have been quite thoroughly worked out. One

fact of most general interest is the determination that a large part of

the placer gold has been derived from the quartz veins in a series of

metamorphic sediments.

The Journada del Meurto of New Mexico is a bolson plain that has.

long been regarded as one of the most desert regions in the State.

Recent studies by Keyes, published in Water Supply and Irrigation

Paper 123, show that the district affords promise as an artesian basin.

The shallow ground-water conditions are not very good, but the porous

Cretaceous sandstone which is folded into a syncline and has the

impervious Permian red beds at its base, affords good water at a depth

of not over 2000 feet, even in the center of the basin. The water is

practically fresh, the slight saline scale deposited by evaporation being

common salt, so that it is adapted to all domestic purposes.

Bulletin 266 of the United States Geological Survey contains the

“Paleontology of the Malone Jurassic Formation of Texas,” by

Francis Whittemore Cragin, with “Stratigraphic Notes on Malone

Mountain and the Surrounding Region near Sierra Blanca, Texas,”

by T. W. Stanton. The report contains 28 plates of fossils, and one

topographic map of the district.

No. 475] NOTES AND LITERATURE 531

E. C. Eckel has prepared a report on “The Cement Materials and

Industry of the United States,” which forms Bulletin 243 of the United

States Geological Survey. The report consists of two distinct portions:

first, the technical processes involved in cement manufacture, and

second, the distribution of cement materials. The cement materials

are divided into the Portland cements, the natural cements, and the

Puzzolan cements. The distribution of each of these different cements.

is treated according to States. The arrangement by States is al-

phabetical, and consequently necessitates repetition, which would

have been avoided if a geological arrangement had been selected.

The 15 map plates are of considerable importance, as they present

much new and accurate information.

An extremely interesting portion of Water Supply and Irrigation

Paper 105, by T. U. Taylor, on the “‘Water Powers of Texas” de-

scribes the Austin dam and its destruction, in April, 1900. The failure

of the dam seems to be attributable to lack of geologic investigation

before construction. This is shown by the fact that the minimum

flow of the Colorado was considerably less than supposed, and also

that an old watercourse filled with sand, etc., was allowed to remain

as a portion of the floor for the foundation of the dam. The photo-

graphs reproduced in the text make it evident that the destruction

of the dam was not due to weaknesses in the dam itself because not.

only the dam but also part of the foundation were carried down

stream.

“The Water Resources of the Philadelphia District," by Florence

Bascom, is published as Water Supply and Irrigation Paper 106 of

the United States Geological Survey. It contains data concerning the

precipitation and run-off for many of the streams. Some of the ob-

servations extend over a period of more than thirty years, so that the

averages may be considered as characteristic of the district. From

these records it appears that in the district as a whole evaporation is

in excess of run-off.

Aseries of five papers regarding the less of the Mississippi

Valley and of Iowa in particular, by Professor Shimek, has re-

cently been received. These papers may be found in the Bulletin of

the Laboratories of Natural History of the State University of Iowa,

(vol. 5, no. 4, pp. 298-381, 1904). These articles support, in a force-

ful manner, the theory of the zeolian origin of loess. Professor Shimek

treats particularly the loess of Natchez, the Lansing deposit of so called

532 THE AMERICAN NATURALIST [Vor. XL

loess, in which the Lansing skeleton was found, determining that this

deposit is really not loess, and arraigns two or three recent supporters

of the aqueo-fluviatile origin of the less.

The rapid development of underground workings at Cripple Creek

and the consequent increase in detailed information has made it desir-

able to resurvey the field. The results — embodied in Bulletin 245

of the United States Geological Survey, “Report of Progress in the

Geological Resurvey of the Cripple Creek Distriet, Colorado,” by

W. Lindgren and F. L. Ransome — furnish an apt illustration of the

present efficiency of the Survey. While there are modifications of

many of the details previously published concerning the geology of

this very complex region, the main facts previously outlined are sub-

stantiated. An interesting note in this report states that the depth to

which the oxydation of the ore bodies has penetrated is oftentimes a

thousand feet.

“A Gazeteer of Indian Territory," by Henry Gannett, forms Bul-

letin 248 of the United States Geological Survey, published in Wash-

ington, 1905. In addition to 59 pages devoted to place names, there

are 6 pages giving a brief description of the larger topographic fea-

tures; population, and products.

Two papers concerning certain deposits of economic significance

in Illinois, prepared by H. F. Bain, have recently been published by

the United States Geological Survey. The first of these is entitled

the “Zine and Lead Deposits of Northwestern Illinois,” Bulletin 246,

and the second is “The Fluospar Deposits of Southern Illinois," Bul-

letin 255. In the former paper, Bain regards the disseminated lead

and zinc minerals as having been deposited apparently from sea water

and contemporaneously with the sediments in which they occur. In

this report, Bain dismisses the other theories of origin in a very per-

emptory manner, and the reader wonders whether they have been

carefully considered.

The volume of ** Contributions to Devonian Paleontology for 1903,”

by H. S. Williams and E. M. Kindle, consists of two distinct parts.

"The first deals with the Devonian and Mississippian faunas of Vir-

ginia, West Virginia, and Kentucky, while the second part treats of

the Devonian of central and northern Pennsylvania. The portion

of the paper dealing with the Upper Devonian faunas of the middle

Appalachians, with a chart showing range of species, is of most general

interest. This report is published as Bulletin 224 of the United States

"Geological Survey, and contains 144 pages, 4 plates, and 3 figures.

No. 475] NOTES AND LITERATURE 533

An interesting preliminary paper by G. O. Smith and F. C. Calkins,

entitled “A Geological Reconnaissance across the Cascade Range

near the 49th Parallel,” is published by the United States Geological

Survey as Bulletin 235. The paper deals with the geology and petro-

graphy of the region traversed. The effect of the prevailing winds,

etc., is strikingly shown by the difference in amount of vegetation on

the east and west sides of the range, and also on the position and num-

ber of glacial cirques. A striking illustration of a glaciated valley is

shown in Figure B, Plate 3.

Bulletin 245 of the United States Geological Survey, prepared by S.

S. Gannett, gives the “ Results of Primary Triangulation and Primary

Traverse for the Fiscal Year, 1903-1904.

Fuller, Lines, and Veatch have prepared Bulletin 264 of the United

States Geological Survey, which presents an epitome of the method of

work, and an outline of the plan of organization of the Division of

Hydrology. The importance of preserving records of the various

strata passed through in well-drilling is strongly emphasized. It is

proposed to collect not only the written description of the kinds of

rock cut, but also to retain a sufficient amount of the original sample

to afford a basis for subsequent study and comparison by members

‚of the Survey.

“The Comparison of a Wet and Crucible Method for the Assay of

Gold Telluride Ores, with Notes on the Errors Occurring in the Oper-

ations of Fire Assay and Parting,’ by W. F. Hillebrand and E. T.

Allen, forms Bulletin 253 of the United States Geological Survey publi-

cations. The paper deals largely with the chemical methods employed,

and concludes that the crucible method is fully as accurate as the wet

method.

The cleavage of rocks is treated in Bulletin 239 of the United States

Geological Survey, a volume of 216 pages, 27 plates, and 40 text figures,

y C. K. Leith. The author proposes to divide cleavage into two

great groups, original and secondary. Under original cleavage, he

includes the parting between bedding planes of sedimentary rocks,

flow structure in lavas, concentric jointing in deep-seated igneous

rocks, ete. The secondary cleavage structures are divided into two

groups, flow cleavage and fracture cleavage. The paper presents a

careful investigation, but it may be questioned whether it is desirable

to group so many unrelated features under one term.

534 THE AMERICAN NATURALIST [Vot 35

Bulletin 237 of the United States Geological Survey is a paper by

L. V. Pirsson on the “ Petrography and Geology of the Igneous Rocks

of the Highwood Mts., Montana.” The report treats mainly the

petrography of this volcanic center, with a brief review of the geology

of the district. The portion of general interest is the bearing of this

region upon the theories of the consanguinity of lavas.

2.8.8

CORRESPONDENCE

The Danish Arctic Station

Editor of the American Naturalist

Sir:—- In the summer of the present year a permanent station for

the study of Arctic science will be established on the south coast of

Disco Island in Danish West Greenland. ‘The cost of the foundation

is defrayed by a gift from Mr. A. Holck, Counsellor of Justice, of

Copenhagen, and the Danish Government has promised an annual

grant of kroner 10,000 ($2,500) toward its maintenance.

A laboratory, equipped with appliances and instruments, especially

for biological researches, will be attached to the Station, and work

places will be furnished for visiting naturalists, foreign as well as Dan-

ish. The visitors will have the free use of the instruments, traveling

outfit, and library of the Station; lodging will be free and a small fee

only will be charged for board. Cheap fare to and from the Station,

via Copenhagen will be provided. The first visitors can be received

in 1907, and notices, inviting application, will be issued in due course.

A library of Arctic literature is to be founded at the Station and to be

made as complete as possible, but in view of the limited resources of

the Station and the vastness of the Arctic literature, only a small pro-

portion of it can be purchased. As the designed leader of the Station,

I venture to ask you therefore, to be good enough to come to its assis-

tance by giving to its library such works on Arctic (and Antarctic)

Nature, and, especially on Arctic biology as you may have published

or are going to publish in the future. The publications of the Station

will, of course, be sent to you in return, and the Station and its leader

will be glad to render you any service in their power.

In view of the arrangements to be made for the purchase of books,

I would be very grateful to you, if you would inform me at the earliest

possible date, whether the present appeal from the Danish Arctic.

Station will have the favor of your kind consideration.

I am, |

Your most obedient servant

Morten P. PorsıLp

BorANICAL GARDEN

UNIVERSITY OF COPENHAGEN

DENMARK

535

(No. 474 was issued June 9, 1906)

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weal asd of the Parthenogenetic Development of Amphi-

John W. Scott.

Ex amination of the Effects of Mechanical Shocks a

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The Daves ment of Funduius Heteroclytus in Solutions of

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Fresh Wate . Charles R. Stockard.

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f Hydroids A. J, Goldfarb.

Partial Resanation of the Sperm Re ecept acle in 'Crayfi sh E. A. Andrews.

Studies on deis ie i 11}: e Sexual Differences of

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ee on the Determinations and Inheritance of Sex . Edmund B, Wilson.

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6 BEACON ST., L BOSTON, MASSACHUSETTS

VOL. XL, NO. 476 z AUGUST, 1906

THE

AMERICAN

NAIURALISIT

A MONTHLY JOURNAL

DEVOTED TO THE NATURAL SCIENCES

IN THEIR WIDEST SENSE

CONTENTS

Page

Volant Adaptation in Vertebrates . . + > PROFESSOR R. S. LULL 537

. External Morphology of the Dugong

PROFESSOR H. DEXLER AND L. FREUND 567

IIL Reproduction of Metridium marginatum by Fragmental Fission

M. L.

Me oe

HAMMATT 583

IV. Notes and Literature: Zod/ogy, Plankton of Northern Seas, Notes on Penn-

sylvania Fishes (H. W. Fowler), Note on Muhlenberg’s Turtle (H. W,

Fowler); Anthropology, The Bontoc Igorot, Notes; Botany, Plants and

Light, Campbell’s Mosses and Ferns, Howe's Common and Conspicuous

Lichens of New England, Czapek’s Biochemistry of Plants; Lacouture’s

Liverworts of France. - oe ee ee

593

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THE

AMERICAN NATURALIST

Vor. XL August, 1906 No. 476

VOLANT ADAPTATION IN VERTEBRATES

RICHARD $. LULL

OF THE several environments to which vertebrates have become

adapted, the two which most profoundly modify their inhabitants

are the water and the air. This is in part due to the fact that a

homogeneous environment pressing upon all sides of the organism

with almost the same intensity has moulded the form into a sym-

metrical contour which offers but little resistance in passing

through the medium. In addition, special modifications of the

limbs must occur, supplemented in air-inhabiting forms by cutane-

ous expansions or appendages for support or propulsion, without

which very existence in the medium is out of the question.

Aquatic life modifies its denizens the more profoundly, because

it becomes permanently sustaining, while even the best of fliers

must ultimately return to the trees, the earth, or the sea. "The

aérial forms therefore always retain functional structures to enable

them to move in the environment from whence their ancestors

came. Of the more perfectly adapted aquatic types this is not

true.

Creatures, other than the aquatic forms, can exist in the terres-

trial realm without special adaptation; many forms which can

climb fairly well may hardly be said to exhibit scansorial modifica-

tion and indeed, while prolonged life in the water profoundly

alters the contours of the animal, many vertebrates are fair swim-

mers whose proper environment is elsewhere. ‘To venture into

the aérial realm without an especial equipment for flight is to

537

538 THE AMERICAN NATURALIST [Vor. XL.

court destruction like Darius Green, though many animals which.

cannot even soar, are wonderful leapers.

With the exception of the Amphibia, every class of vertebrates.

has developed true flight, while the power of soaring from a higher

to a lower level has been acquired again and again.

Altogether no fewer than seventeen separate evolutions for aérial

life have occurred among vertebrates, true flight five and probably

seven' times, and soaring at least ten times. The forms which

soar are singularly uniform in the plan of the sustaining mechanism

and one would be justified in considering many of the volant

mammals as the result of a single evolution were it not for the fact

that in many cases the nearest relatives, which might prove annec-

tant, are flightless forms. In true fliers, however, there is in each

instance so distinct a plan of structure that there is not the slightest

doubt that each has arisen through a separate evolution.

It is necessary to draw a sharp line of demarcation between the

soarers and those having true flight, and the latter are again divided

according to the mode of progression. These are, to use Marey’s

terms, the sailers, forms of great wing expanse like the vultures

which rise slowly, but once in the air sustain themselves on almost

motionless pinions; and the rowers or wing-flappers, such as have

limited alar expanse and must make good this lack by a rapid vibra-

tion of the wings. This type culminates in the hummingbirds,

though including many large birds of great speed as the wild goose.

There are also gradational forms between the two extremes. Nor

are these two methods confined to the birds, for among the ptero-

dactyls it is evident that both kinds of true flight prevailed. Also,

among the bats there are some of rapid wing movement, while others.

flap slowly, tending toward the sailing method of flight.

While the mode of flight is perfectly apparent in most aérial

vertebrates, in some instances it has been difficult to assign the

animal to the proper group as in the case of flying-fishes whose

method of locomotion has given rise to much argument. Mose-

ley’s description of the flight of the albatross (Moseley, '79, p. 570)

‘Tam not sure under which’ head the fossil flying-fishes should come; but.

unless their fin-wings were far larger proportionately than those of modern

types Colonel Durnford’s argument would hold good for them as well and

would place them among the true fliers (vide infra p. 541).

No. 476] VOLANT ADAPTATIONS 539

is another instance of the correction of a popular misconception due

to a lack of knowledge of mechanical principles, for while vultures,

when sailing, are continually sliding down an inclined plane, the

albatross was supposed to sail close to the sea without losing alti-

tude; a manifest impossibility.

CLASSIFICATION

Volant vertebrates may be classed as follows: —

Evolution Soaring Flapping Sailing

PISCES

1 Ganoidei Thoracopterus x

2 Gigantopterus x

3 Teleostomi Exoccetus x

4 Dactylopterus x

AMPHIBIA

5 Anura Rhacophorus x

REPTILIA

6 Squamata Ptychozoön x

7 o x

M Pterosauria (entire order) x x

9 AVES (entire class) x x

MAMMALIA

10 Marsupialia Ptauroides x

11 etaurus X

12 Acrobates — ^ x

13 Rodentia Anomalurus x

Pteromys )

14 Sciuropterus x

Eupetaurus j

15 Insectivora Galeopithecus x

16 Chiroptera (entire 2 x

17 Primates Propithec x

t 2

In all 17 evolutions.

1 Moseley says: “I believe that Albatrosses move their wings much oftener

than is suspected. They often have the appearance of soaring for long periods

after a tea T PR their wings at all, but if they be very closely

watched, v hort f the wings may be detected.

The nn is rather as if the body of the bird dropped a uk short dis-

tance and rose again. The movements cannot be seen at all unless the bird is

exactly on a level with the eye. A very quick stroke, carried even through a

very short are, can of course supply a large nee of fresh momentum. In

perfectly calm weather, Albatrosses flap heavily.

540 THE AMERICAN NATURALIST [Vor. XL

FISHES

The flying adaptation among fishes has occurred at least four

times; twice among recent fishes and fully as often during geologi-

cal times. Dr. O. Abel in the last Year-book of the Austrian Geo-

logical Survey, describes and figures two ganoid flying-fishes from

the New Red Sandstone (Upper Trias). These are Thoracop-

terus and Gigantopterus and they differ totally from the modern

types, except in the development of wing-fins for flight. They

Fic. 1.— Erocetus sp., drawn from an alcoholic specimen. 4 natural size.

resemble their non-flying contemporaries in the possession of

quadrangular, enamel-covered scales which encased the body. :

Of modern types two important genera of Teleostomi have

acquired flight, Exoccetus, a herring, and Dactylopterus, a gurnard.

Exocætus.— This genus embraces forty-four species which are

generally known as the true fiying-fishes in contradistinction to

the fiying-gurnards or gurnets mentioned above.

In Exocoetus flight modification consists in the elongation and

broadening of the pectoral fins and a lesser enlargement of the pel-

vics as well; so that the weight while in the air is distributed,

though unequally, between the two sets of fins as shown in Fig. 1.

The anterior fin-rays are much strengthened, especially toward

No. 476] VOLANT ADAPTATIONS 541

their base, while distally each ray bifurcates to give more support

to the flying membrane. The lengthening of the pectoral fins

varies with the species, being greatest in those with the best powers

of flight.

The bodily contour seems to have suffered but little alteration

due to the development of flight. The lower lobe of the caudal

fin is much the longer and thus becomes more efficient in giving

the fish its final impetus upon leaving the water. It is also said

that the fin is occasionally submerged during flight and aids in

changing the direction of the fish.

Nearly all of the Scombresocidz, to which family this flying-

fish belongs, have the power of taking great leaps out of the water,

culminating in Exoccetus. In the development of the pectoral fin

every gradation may be found between the small pectorals of Scom-

bresox to Exoccetus, Hemiexoccetus being a very remarkable con-

necting form (Boulenger).

Exoccetus is tropical to subtropical in distribution, some species

having an extremely wide range.

The manner of the flight of flying-fishes has been a much vexed

question, one idea being that the creature gets its impetus solely

from the tail while in the water, the wings acting merely as para-

chutes or aéroplanes to support the animal in the air. The other

view is that while the initial start is given by the tail, flight is sus-

tained by an actual vibration of the fins as in wing-flapping birds

and bats. Some authorities have maintained that the fins move

voluntarily only at the beginning and end of the flight, others that

. this apparent movement is due to an occasional vibration caused

by the currents of air.

Colonel Durnford in the January number of the American Nat-

uralist, has effectually settled the question by showing that sus-

tained soaring for such a distance (500 feet, Giinther) is a mechan-

ical impossibility, due to the moderate initial speed, for a creature

of such limited wing-area in proportion to its weight. He further

shows that not only is wing vibration necessary, but vibration at

extreme speed, such as is invisible to most eyes except at the begin-

ning and end of the flight when the fins are accelerating or retard-

ing their velocity. This is in spite of the statement of Möbius (’78,

p- 343) who after examining the musculature as well as watching

542 THE AMERICAN NATURALIST [Vor. XL

the living fish came to the conclusion that the fins are not moved

at all.

Dactylopterus.— In Dactylopterus the pectoral fins are espe-

cially developed for flight and they alone give support to the body

in the air as the pelvic fins, which are situated just beneath the

pectorals, are not visible from above even when extended. The

pectoral fins as a compensation are much broader than in

Exoccetus, the relative alar expanse compared with the bulk

of the body being much the same in the two genera (compare

Figs. 1 and 2).

In the present form the entire body is heavier and of more robust

Fic. 2.— Dactylopterus volitans. From an alcoholic specimen. 1 natural size.

build and the strongly armored head is flattened beneath. The

tail in Dactylopterus is symmetrical, not with a larger lower lobe

as in Exocoetus.

The pectoral fins, aside from their greater breadth, differ from

those of the latter genus in having more membrane in proportion

to the supporting fin-rays, making a less rigid organ. In the young

ying-gurnards, formerly thought to represent a distinct genus,

Cephalacanthus, the pectorals are so much shorter than those of

No. 476] VOLANT ADAPTATIONS 543

the adult that they are unable.to raise themselves out of the water

(Giinther).

Moseley (’79, p. 571) says: “I have distinctly seen species of

Flying Gurnets move their wings rapidly during their flight... .

especially in the case of a small species of Dactylopterus with beau-

tifully coloured wings, which inhabits the Sargasso Sea.” He

further says that he has never seen any species of Exoccetus flap

its wings which must be taken as indicating that in Dactylop-

terus the movement is much slower so as to be distinctly visible.

This one would be led to expect from the feebler wing structure

and the result is a much less developed power of flight. Moseley

likens the flight of the gurnets to that of grasshoppers.

Boulenger (:04, p. 701) recognizes four species of Dactylopterus

which are found in “the tropical and warm parts of the Atlantic

and Indian Ocean and Archipelago.”

AMPHIBIA

The only volant adaptation among the Amphibia is that of the

tree frog, Rhacophorus, in which the webbed feet bear the creature

>> j 4

Fia. 3.— Rhacophorus rheinhardtii. After Duméril and Bibron. Natural size.

up during the prolonged leaps that it takes from tree to tree.

'This genus includes more than forty species and has a wide dis-

544 THE AMERICAN NATURALIST [Vor. XL

tribution in the paleotropical realm. It was first described by

Wallace (’69, p. 38) who evidently through error exaggerated the

extent of the supporting membranes very much. The generic

name is derived from the presence of the small dermal flaps seen

especially at the heel.

The digits terminate in adhesive pads and are connected by

web-like expansions of skin which also extends between the two

outer metatarsals. Membranes are developed as well in front and

behind the arms, rudiments of the prepatagium seen in higher forms.

The figure (Fig. 3), which is modified from that of Duméril and

Bibron (’36, pl. 89), is that of Rhacophorus rheinhardtii and shows

a very conservative development of the parachute, though in the

majority of species the web extends not more than half the length

of the fingers. In Rhacophorus pardalis the total alar expanse 1s

about three square inches (Gadow). This would imply rather

feeble soaring powers.

REPTILIA

Reptilia exhibit at least three instances of volant adaptation, the

most notable instance being that of the extinct Pterosauria in which

Fic. 4.— Ptychozoon homalocephalum. After Duméril and Bibron.

true flight was developed, the special adaptation of the entire organ-

ism being second only to that of birds.

Lacertilia.— Among modern types two lizards have the power

of soaring, though in varying degree.

Of these lizards the first is of the family Geckonidæ, Ptycho-

No. 476] _. VOLANT ADAPTATIONS 545

zoón homalocephalum, a remarkable form from the Malay Islands

and the Malay Peninsula. This creature, shown in Fig. 4, is

about eight inches in length, a typical gecko in foot structure, but

with membranous expansions along the sides of the head, limbs,

body, and tail. 'The membrane also extends between the digits

as in Rhacophorus. ‘The membrane of the tail consists of a series

of short flaps on either

side. These extensions

of the skin seem to be

unsupported in contrast

to those of Draco, but

subserve the same func-

tion of supporting the

creature in its soaring

leaps.

The membranes are

discernible in the newly

hatched young (Gadow).

In Draco volans of the

family Agamidee, the sup-

porting membrane is lim-

ited to the sides of the

trunk and is of ample

extent, well supported by

the ribs of which five or

n Fig. 5.— Draco volans. From a mounted specimen.

six pairs extend beyond 3 natural size.

the body wall as shown

in Fig. 5. The membrane is capable of being closed like a fan

against the sides of the body, and its efficiency as a buoyant organ

is increased by the concavity of the inferior surface.

The body is strongly depressed and the tail is extremely long

and slender and must aid the creature in guiding its flight.

There are in all about twenty species of Draco, inhabiting the

East Indies. The power of flight is not very great, but probably

exceeds that of Ptychozoón. |

546 THE AMERICAN NATURALIST [Vor. XL

PTEROSAURIA

The pterodactyls were a remarkable group of reptilian forms

whose remains are known from the Mesozoic rocks, ranging from

the Rhetic to the Upper Chalk. As yet we know nothing of their

ancestry, for the first which appear are in every way characteristic

of the group.

Seeley (:01, p. 229) says: “There is no geological history of the

rapid or gradual development of the wing finger, and although

the wing membrane may be accepted as the cause of its existence

the wing finger is powerfully developed in the oldest known ptero-

dactyls as in their later representatives.

“Pterodactyls show singularly little variation in structure in

their geological history. We chronicle the loss of the tail and the

loss of teeth. There is also the loss of the outermost wing-digit

from the hind foot as a supporter of the wing membrane. But

the other variations are in the length of the metacarpus, or of the

neck, or of the head.” One might add to this an increase of size

as the huge pterodactyl Pteranodon and its allies are among the last

to appear.

The adaptation of the pterodactyls for flight is a very perfect

one, implying not only the development of true wings, but a spe-

cially modified respiratory apparatus coupled with a highly devel-

oped pneumaticity of the bones as in birds. ‘There is also a very

bird-like modification of the brain which is unlike that of any other

reptile. ‘This is seen especially in the width of the hemispheres

which touch the well developed cerebellum. On each side of the

cerebellum lie the optic lobes while the flocculi, lateral appendages

of the cerebellum, which are known elsewhere only in birds, are

well developed (Gadow). :

Skull.— The skull resembles that of birds, exhibiting large

vacuities in some forms and bearing well developed teeth set in dis-

tinct sockets and varying in size. In Pteranodon and its allies

the jaws were toothless and were evidently not sheathed with horn

but with a leathery skin, indicating probably fish-eating habits.

Posteriorly, the skull of Pteranodon is prolonged into a compressed,

No. 476] VOLANT ADAPTATIONS 547

vane-like process evidently not for muscular attachment but to aid

in keeping the head pointing into the wind. This would otherwise

not only require great muscular effort but would probably have

deflected the creature from its course. The head is articulated at

right angles with the neck as in birds and in bipedal dinosaurs.

Wings.— The wings consist of the patagium, a broad expanse of

membrane, supported by the fore and hind limbs, a prepatagium in

front of the arm, and an interfemoral membrane extending between

the hind limbs and the tail. The patagium was delicate and very

similar to that of the bats. ‘The surface was marked with delicate

strie, which seem to be minute wrinklings. The membrane, when

not extended, was thrown into longitudinal folds.

Fore Limb and Girdle.— 'The skeleton of the fore limb and girdle

Fic. 6.— Rhamphorhynchus enden Modified from Marsh and Zittel.

About 4 natural size.

shows a remarkable modification for the purposes of flight, differ-

ing markedly from either the bird or the bat. The pectoral arch

is reduced to two pairs of elements, the scapulze and coracoids, as

the clavicles are entirely wanting. In the forms existing before

the Cretaceous period the scapul are saber-shaped and are united

with the coracoids at an angle of less than 90? exactly as in carinate

birds. The Cretaceous pterodactyls differ, however, in that the

scapule, while articulating at right angles with the coracoids, are

directed toward the vertebre uniting with their neural arches.

In Pteranodon the scapula articulates with the coalesced spines

548 THE AMERICAN NATURALIST [Vor. XL.

of several coóssified vertebrae, being, as Marsh says, “virtually a.

repetition of the pelvic arch, on a much larger scale" (Marsh, '82,

p. 254).

The sternum is large with a carina or keel, especially in the ante-

rior part, which extends forward in front of the coracoid articula-:

tions. The keel is but feebly developed in the great sailing forms

like Pteranodon while on the other hand it is very high in Rham-

phorhynchus which evidently flew by flapping the wings rapidly.

The coracoids unite with the sternum by a true synovial joint.

'The most notable feature of the humerus is the form of the prox-

imal articular surface which is saddle-shaped, being concave along

the horizontal axis and convex vertically. There is also a remark-

able development of the radial crest.

'The ulna and radius are nearly of the same size, the latter being

Fic. 7.— Pteranodon sp. Modified from Eaton. About „; natural size.

somewhat smaller, while of the metacarpals, that of the wing fin-

ger is of great size and strength while those of the three preceding

digits are very slender bones. The joint for folding the wing is

between the metacarpals and phalanges, not at the wrist as in birds.

The number of digits is probably five as there are two bones artic-

ulating with the distal carpal on the inner side of the wrist which

Marsh (82, p. 254) interprets as the metacarpal and first phalanx

of the first digit. The phalanx, which he calls the " pteroid bone,"

formed part of the support for the prepatagium, being directed

inward toward the shoulder. Others have interpreted this bone as

an ossified tendon. If Marsh is correct the number of digits would

be five, the fifth being the wing finger.

Hind Limb and Pelvis.— The pelvis is crocodilian in character,

while the hind limbs are bird-like with splint-like fibule and long,

slender tibie. The feet have long metatarsals bearing five digits.

No. 476] VOLANT ADAPTATIONS 549

In Dimorphodon and other long-tailed forms the outer digit resem-

bles somewhat that of the hand, only on a much smaller scale. It

probably also aided in the support of the patagium. In the short-

tailed types, on the contrary, this digit is reduced to a vestige with-

out phalanges.

I have figured for comparison two notable genera, the types of

which may each be found in the Yale University Museum. Of

these, Rhamphorhynchus, representing the suborder Pteroder-

mata Seeley, is a small form from the Solenhofen Slate with a long

tail terminating in a peculiar vertical rudder-like expansion sup-

ported by neural spines above and by the chevron bones below.

This was undoubtedly for steering (Fig. 6).

The other form, Pteranodon (Fig. 7), belongs to the suborder

Ornithocheiroidea of Seeley. It is from the Kansas Chalk, a crea-

ture with an alar expanse of eighteen feet! Vast in comparison

with the diminutive body. In Pteranodon the tail is reduced to

a vestige which afforded but little support to the interfemoral mem-

brane. If one may judge from the relation of wing expanse to the

size of the body it would seem as though Pteranodon must have

had a sailing flight, flapping the wings slowly if at all. It may

have been similar to the albatross (vide supra, p. 539) in habits of

flight, or it may have been unable to fly except on a windy day

when, by facing the wind, it would be able to rise to a consider-

able altitude before its inertia was overcome. Rhamphorhynchus

on the other hand was probably a more active flier exhibiting the

wing-flapping method of flight.

BIRDS

The birds form a remarkably homogeneous group reaching the

climax of volant adaptation. Flight has, however, been lost in

some of the more specialized forms as the penguins among the Car-

inate birds and in the whole group of so called Ratite birds.

In brief, the modifications for flight consist in the alteration of

the fore limb into a wing with a reduced hand and with slightly de-

veloped pre- and postpatagiums, but with the alar expanse increased

by the development of the feathers. The tail also becomes an

550 THE AMERICAN NATURALIST [Vor. XL.

efficient steering organ and adds materially to the support of the

animal in the air as well. Aside from the bodily conformation

which is such as to offer but little resistance to the air in passage,

the respiratory organs seem to show the best adaptation to its mode

of life of all the other mechanisms of the bird.

A very interesting series of comparisons may be made between

the birds and the pterodactyls which must be explained as the

result of convergence, though the evidence of a common ancestry

for the two groups is very strong. Other characters there are in

common with the dinosaurs, explicable in the same way, but

these can hardly be said to be volant adaptations as we have no

evidence that the dinosaurs acquired flight.

Fore Limb and Girdle.— The fore limb and shoulder girdle are

wonderfully adapted to their purpose. In the pectoral arch all

three elements are represented in contrast to the coracoid and scap-

ula in the pterodactyls and the clavicle and scapula in the bats.

The clavicles have united ventrally to form what is technically

known as the furculum which does not always articulate with the

sternum. ‘The scapule and coracoids fuse with each other

firmly, forming in the Carinate an angle of less than 90° as in

the earlier pterodactyls, while in the Ratite the angle formed is

greater than 90°, a feature associated with the loss of flight.

The scapula is saber-shaped, and lies parallel with the vertebre,

with which it never articulates as in the later pterosaurs. The cor-

acoid is a massive, pillar-like bone firmly articulated with the ster-

num. Its duty is to withstand the stress of the great pectoral

muscles which would pull the shoulder toward the breast-bone

were it not for the resistance offered by the coracoid.

The sternum is large, covering in the Carinats much of the ven-

tral wall of the chest and it bears along its midventral line a high

keel or carina for the origin of the muscles of flight. In the Ratite

the keel is wanting, having been lost with the reduction of the pec-

toral muscles. In pterodactyls the sternum is similarly keeled,

though to a less extent, in the smaller forms which had flapping

flight. The keel becomes obsolete except upon the forwardly pro-

jecting process of the sternum in such huge forms as Pteranodon.

which, as we have seen, were probably sailers.

No. 476] VOLANT ADAPTATIONS 551

In the carinate birds the humerus is notable mainly for the size

of the crests which afford attachment for the various muscles.

The humerus is reduced in those birds which have lost the power

of flight and may be entirely absent as in many of the moas.

Seeley (:01, p. 47) tells us of the remarkable similarity which

exists between the foramen in the humerus of the pterodactyl and

that of the bird, by which air enters the cavity of the bone. He

says: “In the Pterodactyle the corresponding foramen has the

same position, form, and size, and is not one large hole, but a retic-

ulation of small perforations, one beyond another, exactly such

Fig. 8.— Archæopteryx macroura.

as are seen in the bone of a bird in which the pneumatic character

is found.”

There are in modern birds but three unequally developed meta-

carpals which are firmly coössified. The digits are represented by

one, or rarely two, phalanges in the pollex which supports the bas-

tard wing, while the second digit, which is much the largest, bears.

two, and the third one phalanx. Claws are sometimes borne on

552 THE AMERICAN NATURALIST [Vor. XL

the first and second digit in modern birds; in Archzopteryx upon

the third as well.

Archzopteryx exhibits naturally a more primitive condition of

structure than do modern birds, but even here the features are truly

bird-like. The sternum is not well known, but the furcula and

the coracoids are like those of existing birds. The wing is shorter

in Arehzopteryx with rather slender bones; the humerus is some-

what longer than the radius and ulna. But one carpal bone is

known though at least one other must have existed. ‘The three

metacarpals are free and each bore a well developed digit termi-

nating in a claw. We do not know whether the second bore any of

the contour feathers as in modern birds or whether they were all

borne on the third finger.

Hind Limb and Pelvis.—'The hind limb and pelvis of birds can

hardly be said to exhibit volant adaptation, unless it be in the devel-

opment of pneumaticity, as their structure is so closely paralleled in

certain of the dinosaurs. It seems rather that the dinosaur-avian

type of limb, or the tendency to acquire it, is an inheritance from a

common ancestor which certainly could not have possessed the

power of flight as the dinosaurs show no evidence of having had

and lost this characteristic.’

Tail.— The tail of the bird shows a distinct flight modification

less developed, however, in Archzopteryx in which the tail was

elongated and lizard-like and bore a pair of oppositely placed feath-

ers on each segment. ‘These evidently were used for steering an

must have afforded a good deal of support to the body as well, in

compensation for the comparatively small wings. "The Neornithes

or modern birds, on the other hand, have shortened tails, several

of the terminal vertebrze having fused to form a pygostyle. Around

this vestigial tail the rectrices are arranged fan-wise making a very

efficient organ for steering and for checking the rapidity of flight.

A comparison of the figure of the pigeon (Fig. 9) with that of

Archsopteryx (Fig. 8) is interesting as showing the increase in the

expanse of the wings to compensate for the reduction of the tail so

that the relative buoyant surface remains approximately the same.

The Trunk.— The rib structure of the Neornithes must be con-

sidered as a definite flight modification for here only do we find the

No. 476] VOLANT ADAPTATIONS 553

sternal and vertebral ribs articulating by a true synovial joint.

This, together with the elbow-like flexion of the joint, forms an

admirable mechanism for the dorso-ventral increase and decrease

of the chest cavity during respiration. When the bird is resting

the back is rigid and the sternum moves, but during flight when

the sternum is supporting the creature it is the back which rises

and falls.

The long slender neck and the tendency on the part of the trunk

vertebre to coössify, are further skeletal characteristics of birds.

Respiratory Organs.— While all of the nutritive organs are neces-

sarily larger and more efficient in birds as the direct result of more

Fic. 9.— Columba livia. Modified from Parker and Haswell.

rapid expenditure of energy during flight, the respiratory organs

show the most remarkable adaptation. The lungs are inelastic

and do not hang freely in the cavity of the chest as do those of mam-

mals, but are connected with an extensive series of air sacs, prin-

cipally in the abdomen, but in other portions of the body as well.

‘These serve not only to lighten the specific gravity of the bird, but,

by means of the abdominal sacs, air is drawn through instead of

merely into the lungs with the result that the air in the latter is

entirely renewed with each inspiration. There being thus no resid-

ual air, the entire lung functions for the aération of the blood.

The respiratory system is further connected with the cavities with-

in the bones as in pterodactyls and while this pneumaticity is evi-

dently an aid to flight as it reaches its maximum development in

such powerful fliers as the pelicans, it is on the other hand but little

554 THE AMERICAN NATURALIST [Vor. XL

developed in the gulls which are also strong of wing. Seeley says:

“Comparison shows that in so far as the bones are the same in the

bird and ornithosaur, the evidence of air cells entering them extends

to resemblance, if not coincidence in every detail. No living group

of animals except birds has pneumatic limb-bones, in relation to the

lungs; so that the identical structures in the bones were due to the

same cause in both living and extinct groups of animals" (Seeley,

:01, p. 50).

Brain.— In the avian brain the convergence’ toward that of

the pterodactyl lies in the position of the optic lobes which are lat-

erally displaced so that the cerebrum may extend between as well

as over them in order to abut against the cerebellum. ‘There is

also a similarity in the development of the lateral lobes or floceuli

upon the sides of the hind brain. These features seem to be adap-

tations correlated with the development of flight.

MAMMALIA

'The Mammalia show at least eight distinct flight evolutions.

In seven instances soaring has been developed as an aid to pro-

longed leaps, while the Chiroptera as an order are true fliers. This

should not surprise us for all but one of the forms are arboreal and

with arboreal types the development of parachutes for sustaining

the creature in the air during its passage from tree to tree is a logi-

cal course of evolution.

M arsupialia

Among the marsupials of the family Phalangeride there ‘are

three genera, Petauroides, Petaurus, and Acrobates, which have |

independently acquired the power of soaring; for the three genera

are each in turn especially related to a separate type of non-flying

phalanger. The same observation can be made about the flying

squirrels, Anomalurus and Sciuropterus (Beddard).

! Dr. F. B. Loomis is of the opinion that the brain similarity is due to real

relationship and is not a convergence. He explains in the same way the

similarity of the openings into the pneumatie bones.

No. 476] VOLANT ADAPTATIONS 555

In all of these forms the flight adaptation consists mainly in the

development of a horizontal fold of skin (the patagium) stretched

along the sides of the body between the fore and hind limbs.

Petauroides. — In Petauroides the flying membrane extends

from the wrist to the ankle, but is very narrow along the lower

segment of each limb. The tail is very bushy except for its pre-

hensile tip which is naked inferiorly, and, together with the long fur

which clothes the body, must aid considerably in buoying the

creature up while soaring.

Petauroides includes but a single species, P. volans, the so called

Taguan flying phalanger, found in 5

Australia from Queensland to Vic-

toria. Its nearest ally is Dactylopsila

which, however, has no flying mem-

brane but has the same partially

naked tip to the tail.

Petaurus.— Petaurus has a much |

broader patagium which extends kr mee

from the outer finger to the tarsus; :

there is also a slight extension of

membrane in front of the fore limb. ^47

The tail is very large and evenly

bushy, lacking the naked tip. This

genus contains three species which

are somewhat smaller forms than

Petauroides. They seem to have

been derived either from the genus

Gymnobelideus, which resembles

Petaurus closely except that it is ‘ :

flightless, or from an allied extinct fic. 10.— Jud ON, Modified

form (Lydekker). from Flower and Lydekker.

The geographical range of Petaurus is “over New Guinea and

part of Australia, including the area from the Halmahéra group

of Islands to Victoria.” :

Acrobates.— The third genus, Acrobates, contains two species

of which the individuals are of small size with a narrow patagium

extending from the elbow to the knee along the flank. The buoy-

WAS SS |t

P: ay

rece,

ne,

VOL ALTE bE ret ab ap ep,

ened a,

556 THE AMERICAN NATURALIST [Vor. XL

ant area is increased, however, by the long fringing hairs. ‘There

are striated pads at the extremities of the digits. The probably

prehensile tail has its long hairs arranged on either side as in its

near ally, the pen-tailed phalanger, Disteechurus, which from its

skull and teeth may be very close to the ancestral type of Acro-

bates.

One species, Acrobates pygmeus, is found in Queensland, New

South Wales, and Victoria and the other, A. pulchellus, in Papua,

while Disteechurus is now found in New Guinea. Acrobates is

extremely active with great soaring powers.

Rodentia

Two families of rodents, the Anomaluride containing but one

flying genus Anomalurus, and the Sciuridz containing among others

the flying genera Pteromys, Sciuropterus, and Eupetaurus, have

developed the power of soaring by means of a patagium.

These families represent in each case a distinct adaptation to

volant life, though the three genera of the Sciuridz are closely

related and are not as in the Phalangeride, related each in turn to

a non-flying ally. The convergence of the flying rodents toward the

flying phalangers is very marked though the former are apt to

develop more or less of a prepatagium and an - interfemoral

membrane in addition to the patagium along the flanks. This is,

however, as will be shown, a variable feature.

urus.— The Anomaluride include three genera of which

Anomalurus with six species is the most important. In this genus

the patagium is well developed and is supported by a cartilaginous

process of the olecranon. ‘The membrane extends from the carpus

to the tarsus but narrows along the front of the leg from the knee

down. This is compensated for by an interfemoral membrane

from the heel to the tail a little beyond its base.

A distinctive feature of these forms, while not a volant adapta-

tion but rather an arboreal one, is the presence of imbricated,

keeled scales beneath the tail which apparently aid in climbing.

The tail is not very bushy so that it probably aids but little in flight.

Anomalurus resembles Pteromys but is distinguished therefrom

No. 476] VOLANT ADAPTATIONS 557

and from Sciuropterus by the caudal scales and by the position of

the supporting cartilage. Anomalurus is African in habitat.

The allied genus, Idiurus, differs in minor details from Anoma-

lurus, while Aéthiurus from the French Congo, has no flying pata-

gium.

Pteromys.— Among the Sciuride, Pteromys has a patagium

extending as far as the digits and supported as in Anomalurus, by

a cartilage, but one arising from the carpus rather than from the

KR Pr

Fie. 11.— Sciuropterus volucella. From a mounted specimen, 4 natural size.

olecranon. In addition to the interfemoral. membrane extending

to the root of the tail, there is also a narrow prepatagium run-

ning from the anterior limb to the sides of the cheeks. The tail

558 THE AMERICAN NATURALIST [Vor. XL

is larger. than in Anomalurus and must add materially to the sup-

port of the body in the air. It is said that Pteromys can soar

through a distance of nearly eighty yards, depending of course upon

the initial altitude above the ground.

Pteromys is found in the “wooded districts of tropical south-

eastern Asia, Japan, and some of the Malaysian Islands ” (Heil-

prin).

Sciuropterus.— Sciuropterus, which is here figured (Fig. 11),

has no interfemoral membrane, but as a compensation, the tail is

much more fully developed than in Pteromys. In the latter it is

round and comparatively thin while in Sciuropterus the tail is flat

and broadly expanded. A hairy fringe extends beyond the margin

of the patagium and behind the femora as well, thus extending the

supporting area as the figure clearly shows.

Sciuropterus includes smaller forms than Pteromys, but its range

is much more extensive as it includes the northern part of North

America and the Eurasian continent.

Eupetaurus.— Eupetaurus resembles Pteromys but has no inter-

femoral membrane. It differs from the preceding forms mainly

in having hypsodont teeth rather than brachyodont which implies

a difference in feeding habits. Eupetaurus is rock- and precipice-

inhabiting rather than arboreal and inhabits the high elevations

of northwestern Kashmir.

Insectivora

Among the Insectivora, Galeopithecus stands alone in its volant

adaptation for it shows the greatest specialization for flight of any

of the Mammalia except the bats. Indeed Galeopithecus, while

too specialized to be ancestral to the Chiroptera, is evidently from

a common stock and gives us a pretty clear idea of the characters

of the forms from which the latter arose.

In Galeopithecus, which is an animal of considerable size, the

patagium is well developed and is supplemented by a prepatagium

and an interfemoral membrane which includes the entire tail pre-

cisely as in the insectivorous bats. The patagium is well supplied

with muscles and nerves which are homologous with those in the

No. 476] VOLANT ADAPTATIONS 559

wing membrane of the Chiroptera and differ decidedly from those

of the other volant Mammalia.

The hand is much larger than the foot and the flying membrane

is continued along the side of each as well as between the digits, and

while the fingers show no trace of the elongation so characteristic

of the bats, if such were to occur the result would be a very bat-like

structure.

Galeopithecus is unique in the character of the teeth which are

adapted to a phytophagous or leaf-eating habit, while the alimen-

tary canal resembles that of the Chiroptera except that in Galeo-

pithecus the colon is long, while in bats as in birds the colon is

very short. This shortening of the colon is clearly a volant char-

acter due to the freedom with which excrement may be voided by

Fic. 12.— Galeopithecus. Modified from Wood.

aérial forms and the consequent lack of necessity for a place of stor-

age of effete matter.

The brain in Galeopithecus is midway in its development

between that of a typical insectivore and that of a bat.

560 THE AMERICAN NATURALIST [Vor. XL

Galeopithecus is nocturnal in habits, as indeed almost all volant

mammals are, resting during the day by clinging head downward

from the branch of a tree, in which posture it resembles Pteropus.

very closely. Its soaring powers are very great as one has been

seen to cover a space of seventy yards with a descent of not more

than thirty-five or forty feet, or less than one in five (Wallace).

Two species of Galeopithecus are known, one, G. volans, from

the Malay Peninsula, Sumatra, and Borneo, while G. philippinen-

sis inhabits the Philippine Islands.

Chiroptera

In the bats one sees the culmination of volant adaptation on the

part of the Mammalia and the entire order has reached a state of

perfection excelled only by the birds and pterodactyls. Each of

the three solely air-breathing classes of vertebrates has, in one

line of evolution at least, culminated in perfect adaptation to aérial

life.

The bats while showing the same general plan of structure

throughout, are divisible into two distinct suborders in which con-

stant distinguishing characters have arisen, due to differences of

habits. These are the Microchiroptera and the Megachiroptera.

the former being in the main insectivorous while the latter are fru-

givorous in habits. Each group, however, contains some aberrant

forms.

The Patagium.—'The most notable volant characters are the

great development of the digits of the hand supporting the pata-

gium which extends along the sides of the body and hind limb to

the tarsus. There is a well developed prepatagium extending from

the neck to the wrist. An interfemoral membrane is also present,

but varies in development in the two suborders, including the

somewhat elongated tail in the Microchiroptera, while in the tail-

less Megachiroptera each membrane is a triangular area meeting

its fellow at the end of the spine. In the Microchiroptera the mem-

brane is further supported by a cartilaginous rod, the calcar, arising

from the heel and directed obliquely inward toward the tip of the

tail. The development of the tail gives, with the interfemoral

No. 476] VOLANT ADAPTATIONS 561

membrane, an efficient organ for steering and checking the way of

the animal during flight, so necessary in the pursuit of insects and

which gives to the twilight bat its characteristic flight. It is also

said that this structure is of use in the capturing of prey.

. In the vampire and other aberrant carnivorous Microchirop-

tera, there is no tail, a point of agreement with the frugivorous

forms. The tailless bats are much heavier fliers as a rule, flapping

their way slowly through the air.

'The patagium is naked, being clothed with hair along the sides

Fic. 13.— Vespertilio noctula. Modified from Flower and Lydekker.

of the body only, and the surface of the integument is finely wrin-

kled as in the pterodactyl Rhamphorhynchus. The method of

folding the wing when at rest is also the same. The contrast be-

tween the wing of the bat and that of the pterodactyl is in the sup-

port of the membrane in the former by four digits, only the pollex

being free, while in the latter the outermost finger alone supports.

the wing membrane. The contrast with the bird lies in the reduc-

tion of the digits in the latter to three and in the retrogression of

the patagium whose place as a buoyant surface is taken by the fea-

thers.

The Fore Limb.— The pollex is always free and clawed and aids.

in crawling on level ground, but more especially in climbing. In

the Microchiroptera the second finger while distinct is not free but.

is attached to the third distally so that the two together support the

anterior margin of the wing. The third finger, however, is much

the longest and digits four and five are well developed and free.

562 THE AMERICAN NATURALIST [Vor. XL

In the Megachiroptera the contrast lies mainly in the difference

in wing proportions due to the fact that the second digit is free from

the third and supports a portion of the patagium alone. It is fur-

ther clawed at the tip. A comparison of Figs. 13 and 14 will render

these distinctions clear.

The bones of the wing are very slender with large medullary

cavities, but without any trace of pneumaticity as in birds and

pterodactyls. The shoulder girdle, consisting of well developed

clavicles and scapule, is very strong. The clavicles are curved and

the scapule bear strongly curved coracoid processes. ‘The hume-

rus is well developed but is much exceeded in length by the

radius which is a strong, curved bone while the ulna is much

reduced.

The Hind Limb.— One chiropteran peculiarity which is clearly

a flight adaptation is the backward rotation of the hind limb so

that the knee points towards the rear instead of toward the front

as in quadrupeds. This feature is a distinct disadvantage for ter-

restrial locomotion, making the creature extremely awkward when

upon the ground.

There are five compressed digits in the pes bearing long, curved

claws and used as in Galeopithecus for suspending the creature

head downward when at rest.

The Trunk.— The chest is remarkably capacious to contain the

large lungs and heart which resemble those of birds in their state

of development.

The vertebral column is short owing to the compact form of the

body and the individual vertebree have but little movement and

tend to coóssify in old age. ‘The neural canal is largest in the cer-

vical and thoracic regions, rapidly diminishing toward the rear.

This is due to the large size of that portion of the spinal cord from

which the great muscles of flight are innervated as contrasted with

the feeble development of the posterior portion of the body.

The presternum has a well developed keel as in birds and ptero-

dactyls for the origin of the muscles of flight.

The Brain and Sense Organs.— While the brain of the Chirop-

tera is of as lowly organization as the most nearly allied order, the

Insectivora, certain senses of the bats, especially that of touch,

No. 476] VOLANT ADAPTATIONS 963

have undergone a remarkable degree of development and refine-

ment. ‘This tactile sense seems to reside mainly in the vibrisse,

in the wing membrane, and in the ear pinne which in some types

are very large. More especially is the sense developed in the leaf-

like expansions of the skin about the nose and face in the Rhinolo-

phidz and Phyllostomatide. These appendages are the seat of so

delicate a sense of touch that actual bodily contact with an object

4 Ww

Fic. 14.— Pteropus sp. Modified from Owen.

is not necessary to its perception, but the reflected aérial waves

suffice to stimulate the sense organ. "This is a notable secondary

flight adaptation, not useful as a direct aid to flight, but in guiding

a rapidly moving nocturnal flier it must prove invaluable.

The Chiroptera are practically world-wide in distribution, being

found wherever sufficient food may be procured.

Primates

Among the primates one genus exhibits a small patagium which

aids in soaring. This is the genus Propithecus of the family Lemu-

ride.

In these forms the power of flight is somewhat limited. Flower

and Lydekker give ten yards as the length of the leap, attribut-

ing the soaring to the powerful hind limbs, without even mentioning

the existence of the patagium. Beddard on the other hand speaks

of the “parachute-like fold of skin between the arms and the body

which suggests the more complete parachute of Flying Foxes, etc."

Propithecus includes three species, all from the Island of Mad-

564 THE AMERICAN NATURALIST [Vor XL

agascar. They are diurnal, contrary to the general rule among

volant mammals, though they prefer the morning and evening for

their periods of activity.

SUMMARY

1. Volant evolution has occurred seventeen times among ver-

tebrates, ten of which are merely adaptations for more or less pro-

longed soaring leaps, while in seven instances in all probability

true flight has been developed.

2. Soaring implies, with but one exception, the development

of a foldof skin along the creature’s flanks supported in one instance

by the extension of the ribs beyond the body wall, but generally

stretched between the fore and hind limbs. This fold is often sup-

plemented by others in front of the fore limbs and between the hind

limbs sometimes involving the tail.

3. True flight always implies a more or less profound modifi-

cation of the fore limbs which become, as a consequence, unsuited

to ordinary progression. ‘True flight has been developed once in

each of the classes of strictly air-breathing vertebrates, and prob-

ably at least four times among fishes.

4. With the exception of the fishes, soaring implies also pres-

ent or ancestral arboreal adaptation and this may apply as well to

the true fliers. It is certainly true of the bats, possibly true of the

birds, but of the pterodactyls one cannot be certain.

5. Besides the primary modifications which constitute the

machinery of flight, other portions of the body, especially the

nervous system, the sense and the nutritive organs, may exhibit

secondary volant characteristics. These, as with the primary

modifications, are in direct proportion to the powers of flight.

AMHERST, Mass,

No. 476] VOLANT ADAPTATIONS 565

BIBLIOGRAPHY

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Fishes. Combiidye Natural History, vol. 7. London.

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:02. Observations upon Galeopithecus volans. Proc. Acad. Nat. Sei.

Phila., vol. 54, pp. 241-254.

Dum£aır, A. M. C., er BIBRON, G.

’36. Erpétologie générale ou histoire naturelle compléte des reptiles.

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Characters of Pteranodon (Second Paper). Amer. Journ. Sci.,

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FLower, W. H., AND LYDEKKER, R.

’91. An Introduction to the Study of Mammals Living and Extinct.

London.

Gapow, H.

:01. Reptilia and Amphibia. Cambridge Natural History, vol. 8.

London.

'GÜNTHER, A. C. L. G.

'80. An Introduction to the Study of Fishes. Edinburgh.

HEILPRIN, A.

0 The Geographical and Geological Distribution of Animals. New

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LYDEKKER, R.

A Hand-book to the Marsupialia and Monotremata. London.

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’79. Animal Mechanism: a Treatise on Terrestrial and Aerial Loco-

motion. New York.

Marsa, O. C. i

'82. The Wings of Pterodactyles. Amer. Journ. Sci., ser. 3, vol. 23,

pp. 251-256, pl. 3, 2 figs.

Mansn, O. C.

'84. Principal ee of Krcwiben Cretaceous delete

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566 THE AMERICAN NATURALIST [Vor. XL

Mostus, K.

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(E Ape Zoöl., vol. 30, suppl., pp. 343-382, pl. 17.

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:05. A Student's Text-book of Zoology, vol. 2. London.

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:01. Dragons of the Air. New York.

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’69. The ywi Archipelago. New York.

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EXTERNAL MORPHOLOGY OF THE DUGONG

H. DEXLER AND L. FREUND

In continuation of our previous article in this journal on the

physiology and biology of the dugong, we wish now to treat of its

external morphology. Present knowledge of this subject is indeed

considerably greater than that of its biology though it is still far

from complete and particularly has the want of a good figure of

the animal been felt. Kükenthal was keenly sensible of this and

sought partially to remedy the defect by giving an excellent figure

of a dugong embryo and its snout. It is our hope that the figures

here given will at least in some degree make amends for this lack

of illustrations, since they are from photographs taken by Dexler

on the Australian coast during an expedition for the purpose of

obtaining dugong material for scientific study, supported by the

Gesellschaft zur Férderung deutscher Wissenschaft, Kunst, und

Literatur in Böhmen. It is instructive also to compare these

photographs with the first sketches of the dugong drawn from

Nature by Dr. O. Finsch (Illustr. Zeitung, Leipzig, 1901, no. 3012).

The description as well, is capable of improvement and amplifica-

tion, for otherwise there would have been no object in obtaining

the material.

As regards the size of the dugong, various measurements were

made of several specimens killed and these measurements are here

brought together in the following table.

Table of Measurements in Centimeters

No. and Sex IT 18. 4d 49 Bg 88:78

Total length 273 315 311 245 280 290 300

Greatest girth (hand’s breadth behind flippers) 202 181 200

Axillar girth 175 183

Breadth of caudal fin : 77. 82 77

Length of flipper 28 32 36 34

Breadth of flipper 20 2

567

568 THE AMERICAN NATURALIST [Vor. XL

No. and Sex 7C 1d' 28 42 59g 6g TG

From eye to end of snout

From eye to ear opening 15

From anus to center of margin of tail 80 82 101

From genital opening to center of margin of tail 90 132 156

From navel to center of margin of tail 169 191

Interorbital width 21

Width of snout 24 . 22

Height of snout 17

Depth of mouth cavity 10

Palatal process estab: height) 7.4

Extent of lung sounding (from tip of snout) 160

From these measurements it is seen that the smallest specimen

was a female, 245 cm. in length. The male animals obtained,

measured from 280 to 315 cm. in length, and of these the two

measuring 311 and 315 cm. respectively, were the largest of 25

dugongs captured. The published records of the size of these

animals show some variation. Turner and Finsch have already

pointed out that the older authors were wrong in placing the aver-

age length of the dugong much too high (e. g., Brown, 20 feet),

and indeed all the measurements examined show (cf. Raffles, Owen,

Rüppel, Klunzinger) that the dugong does not exceed 33 meters

in length (see also Finsch). In this, Rapp (8 to 10 feet) and

Fairholme likewise agree. The statement of Brehm, 3 to 5 meters,

is thus somewhat exaggerated. ‘The length of the female is gener-

ally given as slightly less, and in our specimen was 2} meters

(Owen, 2.23 m.; Klunzinger, 2.37 m.).

As to the color of the dugong, Finsch has previously written at

some length, and has brought together the various expressions

that have been applied to this elusive shade. His account and

that of Gill appear to agree with our own observations, namely,

that the dorsal surface is in general a light grayish brown to bright

bronze-brown with a slight metallic shimmer, while the ventral

side is white to bright gray. According to Finsch the younger

animals are almost bright flesh-color. The color of the “dugong

of the Red Sea has been otherwise described (by Rapp, Rüppel,

Brehm) as a dull lead-gray, the back and top of the head more

greenish. The dugong embryos from Australia studied by Küken-

thal were blue-black on the head and brown on the belly, and this

No. 476] MORPHOLOGY OF DUGONG 569

shade became lighter in larger animals. Brehm likewise mentions

dark longitudinal streaks which, however, Kiikenthal did not

observe. Preserved skins become much darker with age until

they are nearly black (Krauss, Finsch).

The skin is in general smooth, almost shining (Riippel, Klun-

zinger, etc.). In case of animals that have been lying on the shore

for some time, the skin, particularly of the dorsal side, shows an

unusual luster. On the back and on the sides of the body there

are numerous scratches and scars. These run in all directions;

intersecting one another, and often are very deep, giving the animal

a peculiar appearance. According to Klunzinger the dried skins

show only a few scars but numerous furrows. Krauss also refers

to the numerous scars and believes that they are due to injuries

Fig. 1.— Australian dugong, antero-lateral view.

from contact with the coral rocks. The back and sides of the

body are thickly studded with Chelonobie and less numerous

Balanus. Finsch and Brehm assert that the skin lies everywhere

smooth and is wrinkled on the stomach only. According to

Riippel there are a few small longitudinal folds on the sides of the

belly. On close examination, however, we find that the skin is

really not smooth throughout, but that there are numerous furrows

570 THE AMERICAN NATURALIST [Vor. XL

and wrinkles particularly on the head and fore part of the body.

Thus many of them run parallel to each other from the corner of

the mouth between the upper lip and the eye. Others pass below

the eye, to radiate out from in front of it. Between the eye and

the ear are many transverse folds which run toward the base of the

flipper. The nuchal region is likewise traversed by wrinkles,

among them a particularly prominent neck furrow. Many others

are present in the region of the eye and will be described in con-

nection with the latter. A deep surface furrow is present at the

junction of the flipper with the body, while dorsal to this, a broad

band of fine wrinkles varying in width passes to the eye. A few

deep furrows traverse the neck ventrally and pass caudally into

numerous longitudinal folds. The navel, genital opening, and

anus lie in these longitudinal furrows which in the old males are

deeper and more numerous. Behind the anus are a few transverse

furrows on the side and these Kiikenthal found in the embryos

as well.

All over the body in little pits stand the hairs, some of which

are living, others dead. They are short and slender yet stiff

bristles, and may readily escape notice on account of their distance

Fic. 2.— Dugong, lateral view.

From sketch by Dexler.

from one another (Finsch) but by passing the hand over the back

of the animal they may easily be felt. They are more numerous

on the back than on the belly (Klunzinger). Their distance apart

according to Krauss is from 0.5 to 0.8 cm., though these figures

can hardly apply to an adult animal. For Kiikenthal in an embryo

the length of whose back was 72 cm., found: the interv

i als between

hairs to be from 4 to 8 mm. Rüppel

i122 8 "us gives the distance in adults

Bs $ MOD PM 1 to 2 inches, and according to our observa-

tions it is not much greater. In an embryo 162 em. long, Küken-

No. 476] MORPHOLOGY OF DUGONG 571

thal found distances of from 2 to 3 cm. even at that early stage.

This observer states particularly that there is a regressive develop-

ment of the hairy covering in Sirenia such as he had shown pre-

viously to a greater degree in case of the Cetacea. Turner claims

to have observed that the hairs were arranged in rows in an embryo

dugong, but of such an arrangement we saw nothing. On the

other hand, we found hairs, scattered to be sure, on the flippers

and caudal fin where their occurrence is denied by Rapp, Riippel,

Brehm, and Finsch.

The body is in general spindle-shaped though not uniformly

round as Rüppel and Brehm state. Anteriorly it diminishes in

transverse diameter so that.the head stands high, while posteriorly

it decreases rapidly in vertical section till the body terminates in

the horizontal caudal fin. The chest is somewhat trapezoidal

in cross section in the middle, and toward the rear, with the decrease

in width of cross section dorso-ventrally, it becomes flattened out

laterally. The head is marked off by a shallow furrow at the neck.

On the back the dorsal processes of the vertebra are distinctly

visible as low eminences all the way to the end of the tail as Owen

has also shown. Riippel noticed this feature in case of the tail

only. The ends of the ribs also are evident along the sides of the

breast. |

The head of the dugong is the part showing the most modeling.

The powerful curved upper mandible — compared by Brown to a

nose of a very pronounced Roman type — the broad obtuse snout,

and the nares situated on the summit of the head, give the latter a

very characteristic appearance. We shall consider its peculiar-

ities first through a study of the figures before going into the some-

what contradictory accounts in the literature of the subject. The

head consists of a strikingly heavy skull and upper jaw and the

small lower jaw almost lost to sight underneath it and separated

from the cranium by the mouth cavity which slopes obliquely for-

ward and downward. As before mentioned the head is marked

off by a furrow at the neck. Ventrally, opposite the nape, a sharp

clear boundary is made by a right-angled fold of skin. Seen from

above, the head is longitudinally rectangular, considerably smaller

than the neck, while the height of the head in side view is not

greatly different from that of the neck. The top of the head

572 THE AMERICAN NATURALIST [Vor. XL

curves sharply down on each side to the eyes. Anteriorly, toward

the nostrils this arching is very slight, corresponding with the

decrease in width of this region. The crown of the head is with-

out hair, whereas the remainder of the upper portion is set with

transparent bristles, from 4 to 5 mm. long, that arise from dark-

colored pits. The sides of the upper jaw fall away rather sharply

from the summit of the muzzle, downward and forward. From

the nostrils, which are situated high on the head, the anterior

portion slopes at first gently then bends strongly down to the

mn ™ 8

Fic. 3.— Dugong's head, anterior view. a, lateral fold; b, lateral furrow: c, central

area; d, median furrow; l

me ; 6 lower limiting fold; f, mandible; g, intermediate

fold; A, incisor tooth; i, chin fold; j, palatal process.

mouth, to form the remarkable surface of the snout which is

peculiarly modified on its lower portions. This area is broadly

horseshoe-shaped, somewhat convex anteriorly, with the point

directed a little obliquely forward and downward

It is from 22

to 24 cm. broad and 17 cm. high.

In the living animal the snout is soft and flexible and consists

of a solid muscle mass traversed by fatty tissue, wherein the fiber

bundles intersect in a complicated fashion as in the tongue. The

skin of the snout is so very delicate and pliable that it may readily

No. 476] MORPHOLOGY OF DUGONG 573

be gathered into a very narrow fold between the fingers. The

surface of the snout is differentiated into (1) a middle portion, (2)

its ventral posterior fold, and (3) the two lateral folds. The mid-

dle area is of the shape of a broad horseshoe. On its lower part

there is a sharp median furrow which becomes lost ventrally in the

gums, and likewise disappears in the dorsal third. ‘The anterior

half of this furrow is much shallower than the posterior. The

entire surface is striated with numerous wrinkles which can be

seen to have definite courses. Anteriorly, curves predominate

whose convexity is forward while posteriorly there start on each

side of the median line numerous wrinkles, at first parallel with

Fic. 4,— Dugong’s head, lateral view. a, M fold; b, lateral furrow; c, centr al

area; d, mandible; e, incisor; f, chin fold; g, palatal process; h, chin; i, ear;

j, fold at the flipper; k, furrow at the flipper; l, Alpper A

one another, that radiate out towards the sides and, running for-

ward, cross those first mentioned. On the folds thus produced

stand thick short bristles. Dorsally the median surface of the

snout passes into that of the general integument of the anterior

dorsal region.

~ oOo &

574 THE AMERICAN NATURALIST [Von XL

The demarcation of this middle area posteriorly is effected on

both sides by a low broad fold which is crossed by the median

furrow but begins at some distance from it and, becoming better

defined laterally, passes downward and backward toward the

corner of the mouth. ‘Then on both sides it passes into the side

fold of the middle area. Opposite the mandible, relatively oppo-

site the gums, the lower fold becomes greatly enlarged though in

the figure this feature does not appear since the flabby snout of

the animal as it lay on its back, has sunken down. Nevertheless

there is visible in this position an intermediate fold on both sides

which fills the space between the corner of the mouth, the lower

fold, and the mandibular process. The posterior limiting fold is

likewise thickly set with the bristles previously mentioned. The

middle fold, particularly toward the furrow, also shows these stiff,

backwardly directed bristles.

The lateral folds are comparatively small and are separated

from the middle area by a deep indentation. In the figure, these

furrows gape apart on account of the depression of the snout.

Numerous transverse wrinkles that intersect on the inner and outer

sides, as well as an abundance of bristles along the borders are

present on these lateral folds. They begin rather well up toward

the dorsal part of the snout, and with a gentle lateral sweep, en-

close the middle area and with a strong curve pass posteriorly

toward the corners of the mouth. Here they merge with the pos-

terior fold and at the same time the limiting furrow becomes very

shallow. Beneath the snout and completely hidden by it when in

the normal position, is the mandibular process covered by the

gums. In the male this process bears on each side a short but

stout incisor. 'lhe gum has a median anterior groove. Below

the end of the mandible and the points of its projecting teeth is a

strong firm palatal process that consists of solid fibrous tissue and

reaches beyond the incisors. It is about twice as wide as thick

(7 em. to 4 em.) and with its rounded anterior end bears a certain

resemblance to the tip of a tongue. It is not retractile and is

clearly visible between the jaws even when the latter are closed.

From the fact that the furrows made in the sand by the dugong

in grazing are of the same width as these palatal processes, it may

be concluded that they play a part in the taking of food.

No. 476] MORPHOLOGY OF DUGONG 575

The shortened lower jaw is directed diagonally downward and

extends backward with a breadth corresponding to that of the

narrow mandibular cavity which is but 10 cm. deep. ‘The ante-

rior portion of the lower jaw is narrow and becomes rounded at

the tip so that not only is it well set off from the neck but the angles

of the mouth are also strongly drawn in. The transverse diameter

of this chin-like projection is considerably greater than its length.

Fic. 5.— Dugong's head, ventral view. a, lateral fold; b, lateral irse c, central

area; d, median furrow; e, palatal process; f, chin fold; g, chi

The greatest length is in the plane of the mouth, for as is seen in

profile, the outline of the chin starting from its origin at the neck,

constantly recedes from the mouth till it bends down again to the

tip of the jaw. ‘The greatest transverse diameter is about in the

middle between the corners of the mouth, along the line marking

the origin of the chin from the neck, for the line defining the chin

posteriorly is bent down on each side toward the corners of the

mouth, like a pair of tongs. Along the margin of the mouth on

576 THE AMERICAN NATURALIST [Vor. XL

each side of the lower jaw is a low narrow ridge which is marked

off by a slight furrow from the rest of the chin. This ridge as well

as a broad adjacent strip of the chin is thickly set with short fine

bristles. "The remainder of the surface of the chin bears coarser

and more scattered bristles each of which springs from a small

dark pit, just as in the case of the fold at the edge of the mouth

near the palatal process.

In reviewing the literature on this subject we will first consider

the account given by Riippel. Contrary to our observations, he

states that the long median furrow of the snout is bifurcate ven-

trally so that its form is that of an inverted Y. By this bifurcation,

this portion of the snout is divided into three parts, the two upper

of which belong with the nose while the small lower triangular

part forms the upper lips proper, directed toward the inner sur-

face of the mouth. It is of course obvious that the long vertical

furrow spoken of by Riippel is identical with that described by us.

The bifurcation which, as our description shows, has nothing

particular to do with the median furrow, is the bow-shaped depres-

sion formed by the snout proper and the palatal process. The

small three-cornered portion below is the palatal process, which

of course has no connection whatever with the lips. Rapp speaks

in only a general way of the Sirenian snout. He states that the

upper jaw ends anteriorly in the form of a flat blunt disc richly

provided with nerves, that perhaps functions as an organ of taste;

and further, that in the case of the dugong particularly, the “lips”

are very thick and they as well as the corners of the mouth toward

the inner side of the cheeks bear thick stubby bristles. Krauss

makes no mention of the median furrow of the snout but describes

the side folds which Rüppel omits. Both authors give detailed

accounts of the distribution of hair on the snout. Krauss, how-

ever, correctly describes the palatal process and the fold at the

edge of the lower jaw. Brehm and Finsch make mention of the

head in a few words as does also Owen who considered its peculiar

form to be especially adapted for the taking of food. Turner

gave an extended account of the head of an adult female dugong

but a comparison of his figure with ours shows that the preservation

of his specimen with dry salt must have been very poor for it is

greatly shrunken and out of shape. In consequence, the descrip-

No. 476] MORPHOLOGY OF DUGONG oid

tion based on this; specimen can be only partially followed. For

the median furrow is brought into connection with the furrows

between the middle area and the posterior limiting folds as if it

were bifurcate. The side folds end in a point posteriorly and are

not continued into the posterior fold, which instead comes from

the lateral portions of the middle area (Figs. 3, 5). Turner

describes the greatly shrunken palatal process in his specimen as

“middle lip (mesial process)" notwithstanding that it has no

genetic connection with the lips. The middle area, on account

of its being cut by the median furrow, is misleadingly called *'lat-

eral lips," so that in considering the homologies of the parts men-

tioned, it is necessary to take into consideration the probable

shrinkage that they have undergone.

Of particular interest, naturally, are the embryological condi-

tions as pictured in Kükenthal's sketches of a freshly preserved

fetus. "These sketches are much more satisfactory than the figures

of the fetus given by "Turner. In all the embryos the deep median

furrow of the middle area is apparent. In his fourth stage, Küken-

thal was able to make out a shallowing of this furrow in the region

of thelip. From the fact that this portion of the furrow was lack-

ing in Turner’s figure of the adult, Kükenthal concluded that a

fusion had here taken place between two originally separate por-

tions in such a way that the two lateral parts of the upper lip had

become united medially. In further support of this view, he cited

Rüppel's figure, which as we have shown above is to be otherwise

interpreted and is thus unavailable as evidence on this point. In

our specimen the median furrow extended to the gum, and, since

Turner’s figure is untrustworthy, it can hardly be held that the

two portions of the middle area are united at the posterior part of

the furrow. At the same time we do not wish to contest Küken-

thal's conclusion that the snout of the dugong, which in the adult

is rather simple, has become like that of the manatee through a

division into a median area and two lateral areas and that thus the

manatee's snout is phylogenetically the older. For with this con-

clusion we are in hearty sympathy. This third median portion

is to be found at the upper end of the median furrow as indicated

by its upper bifurcation in a fetus of 72 cm. (Kükenthal), and an

almost horizontal bifurcation in a fetus of 162 em. in length (Tur-

578 THE AMERICAN NATURALIST [Vor. XL

ner). At an early period the two lateral folds are formed and are

marked off in the embryo by a lateral furrow which is wanting in

the adult, or is apparent in certain places only (Kükenthal). The

side folds, which at first converge dorsally in the embryo, later

become parallel, and finally in the adult become divergent above.

The growth in breadth of the middle area is correspondingly

greater in its upper than in its lower portion. The two posterior

limiting folds of the middle area appear to be formed later. They

are figured by Kükenthal from an embryo 162 cm. long. In the

embryo the surface of the snout is marked off into little spaces with

a beautiful regularity and from the center of each knob-like space

rises a hair. ‘The form of the palatal process and of the lower jaw

in the embryo is not greatly different from that of the adult.

A short distance above the snout are the blowholes. These are

two almost circular openings, close together and directed obliquely

upward and forward on the muzzle. Owen characterizes their

high dorsal position on the curve of the intermaxillary as one that

is very advantageous for breathing. In our figures the nostrils

are open, as usual in dead specimens. When the nostrils are

closed, the muzzle is arched forward and slightly rounded. In

our specimen we found nothing that might be called a valve-like

structure, such as Riippel and Turner mention, but this subject

we have treated at length in our previous paper as regards both

the dugong and the manatee (Amer. Nat., vol. 40, pp. 49-72).

The eyes are situated on the side of the head, 18 em. behind the

tip of the nose in specimens of average size, and are about equi-

distant from the end of the snout and the corners of the mouth.

They are visible through a narrow spindle-shaped opening that

slants obliquely upward, and is 12 mm. long (Owen also). The

eyelids are thick and tumid, and only feebly movable up and

down; they are provided with a contractile muscle, the musculus

orbicularis oculi. At the anterior corner the nictitating membrane

is clearly visible (cf. also Rapp and Owen). There is no trace of

eyelashes although Brehm speaks of them regardless of Riippel’s

correct assertion that they do not exist. The bulbi are small and

nearly spherical, though not egg-shaped as Brehm states. The

iris and choroid layer are black-pigmented so that the whole eye

-appears dark.

No. 476] MORPHOLOGY OF DUGONG 579

In the region where the head passes into the neck, there is on

each side of the former, at the end of a transverse series of neck

furrows, the small ear opening. This is in a scarcely noticeable

depression of the skin about 3 mm. in diameter, at about the same

level with the eye and some 15 em. behind it. There is no external

ear and Turner found none in the embryos.

The external form of the two pectoral appendages, which arise

not far from the head toward the ventral side of the body and pro-

ject laterally, has been rather exhaustively treated in a work on

their osteology by Freund. It remains to say, however, that the

flippers are usually directed backward along the sides of the body,

so that a thick fold arises above the furrow at the insertion. ‘The

upper surface is darker than the lower. The absence of hair on

the flippers has already been mentioned. In the adult animal,

the extreme length of the flipper is not over 32 cm., and the great-

est breadth is 20 cm. or a trifle more.

The mamme are short, hard, cone-shaped structures as thick

as one’s thumb. They are situated, one on each side, in the

axillary region, behind the furrow of the flipper, as Owen and

Rüppel also state, and are seen well from the ventral side. Ac-

cording to Owen, their bases in the case of a female specimen were

about the size of a shilling, and they rose about one half an inch

above the surrounding surface. ‘Turner found no trace of mamme

in an embryo 162 cm. long.

As to the rest of the body there is but little to be said on account

of the few peculiar characters it possesses. In the middle of the

belly is the navel and 40 cm. behind it is the preputial opening or

the vaginal furrow as the case may be. The latter is a slight cleft

about 10 cm. long (cf. Klunzinger also) and is hardly to be differ-

entiated from the anus. It lies slightly nearer the middle of the

tail — 90 em. (100 according to Klunzinger) — than the penis

which is from 132 to 156 em. distant from the navel. On these

points Bischoff has published some observations. The anal

opening and the vagina are closer together than are the penis and

the anus. In animals that have been dead in the nets for some

time and in which decomposition has begun, the penis is usually

prolapsing. It is covered by an unpigmented skin and ends in a

conical point with two large lateral lips.

580 THE AMERICAN NATURALIST [Vor. XL

The caudal portion of the body consists of a horizontally flat-

tened fin, with a very slight indentation at the posterior margin.

Its breadth is from 77 to 82 em., and on this point Raffles and

Owen also agree. There is no indentation in the shape of a half

moon such as Rapp, Riippel, and Brehm mention, but the posterior

margin is feather-edged and often is considerably torn. Accord-

ing to Owen the tail is relatively larger than in the whales, and this

he explains as due to the frequent necessity for coming very quickly

to the surface for breath while feeding.

LITERATURE

Biscuorr, T. L. W.

'4T. Einige Beiträge zur Anatomie des Dugongs. Müller’s Arch. j.

Anat., pp. 1-6.

BREHM.

’91. Tierleben, 3. Aufl. v. Pechuel-Loesche: Säugetiere, 3. Bd., Leipzig.

Brown, A. E.

’78. The Sirenia. Amer. Nat., vol. 12, pp. 291-298.

Dexter, H.

:02. Bericht über eine Reise nach Australien. Deutsche Arbeit., vol.

1, pp. 552-562.

DEXLER, H., anp FREUND, L.

:06. ar bakom of the Physiology and Biology of the Dugong.

Amer. Nat., vol. 40, pp. 49-72.

FAIRHOLME, J. K. b

'56. On the Australian Dugong (Halicore australis). Proc. Zool.

Soc. London, vol. 24, pp. 352-353.

FınschH, O.

:01. Der Dugong. Zool. ethn. Skizze einer untergehenden Sirene.

ium gem. verst. Vortr., Holtzendorfj-Virchow, H. 359. Ham-

urg

FrEunD, L.

:04. Die Osteologie der Halicoreflosse. Zeitschr. f. wiss Zool., vol.

77, pp. 363-397.

No. 476] MORPHOLOGY OF DUGONG 581

KLUNZINGER, B.

78. Die Wirbeltierfauna im und am roten Meere. Zeitschr. Ges.

Erdkunde, Berlin, vol. 13, pp. 61-96.

Krauss, F.

10. Beiträge zur Osteologie von Halicore. Arch. f. Anat. u. Phys.,

pp- 525-614

KÜKENTHAL, W.

’97. Vergleichend-anatomische, und entwicklungsgeschichtliche Un-

tersuchungen an Sirenen. Denkschr. med. nat. Ges. Jena, vol.

7, pp. 1-75.

LANGKAVEL, R.

'906. Der Dugong. Zool. Garten, p. 337.

OWEN,

38. On the Anatomy of the Dugong. Proc. Zool. Soc. London, vol.

6, pp. 28-45.

Rarrrzs, T. S

'20. Some Account of the Dugong. Phil. Trans. Roy. Soc. London,

pp. 174-182

Rapp, W.

'87. Die Cetaceen, zool. anat. dargestellt. Stuttgart u. Tübingen.

RÜPPEL

"34. Doting des im roten Meere vorkommenden Dugong. Mus.

Senckenberg., vol. 1, pp. 95-114.

TURNER, W.

’94. The foetus of Halicore dugong and of Manatus senegalensis.

Journ. Anat. and Phys., vol. 28, pp. 315-332.

REPRODUCTION OF METRIDIUM MARGINATUM

BY FRAGMENTAL FISSION

M. L. HAMMATT

During the autumn of 1897, a specimen of Metridium margina-

tum, about one half an inch in diameter at the base, was kept by

the writer for some weeks in a glass jar in an open north window.

Its favorite resting place was near the edge of the sea water, where

it could be plainly seen both from above and through the side of

the glass. One morning it was noticed that its tentacles were

withdrawn, that it had evidently moved toward one side, and that

whereas the night before its basal outline had been quite regular,

it now showed a slight inward curve, opposite to which, at a short

distance from it, was a fragment which had evidently been divided

off during the night. The separation between the two was not

quite complete, as a transparent thread passed from one end of the

fragment to the parent form, disappearing, however, soon after.

The distance between the two was gradually increased and the

fragment was seen to possess life, because it changed shape from

time to time.

This fragment was carefully watched for a few days and was

seen to curl together gradually until its extremities met, but the

opportunity for following its further development was wanting.

Later on it was discovered that this reproduction by fragmental

fission in Metridium was mentioned by Verrill in an article entitled

“Our Common Sea Anemone” in the second volume of the Amer-

ican Naturalist, also that similar reproduction in Anthea cereus was

noted by Gosse, in Sea Anemones and Corals, 1860 (page xxi of

the introduction and page 169), and in Tenby, where he states, on

page 373: “If the body be torn away and only a portion of the

base remain, from this fragment a new offspring will sometimes.

583

584 THE AMERICAN NATURALIST [Vor. XL

rise up to occupy the place of its parent." Dicquemare and

Dalyell also observed the same mode of division in sea anemones.’

` When the observation of the writer as above recorded was men-

tioned to Professor A. Hyatt, he remarked that reproduction by

fragmental fission in Metridium marginatum had not, to his

knowledge, been thoroughly studied and figured, and suggested

the advisability of pursuing the investigation further with a view

to publication, adding that a series of drawings illustrative of the

process observed would be of value as an aid in the teaching of

asexual reproduction. In accordance with this suggestion and in

the hope of ascertaining whether forms thus produced developed

later into whole organisms, more small specimens of the same

genus were collected in June, 1898, in the same tidepool from

which the former Metridium mentioned had been taken. This

tidepool was a small one and in it, especially along the edge,

under the overhanging seaweed, the Metridia were numerous.

Fragments were sought for and readily found in abundance not

far from the mature forms. These were in various stages of the

process of curling together and obviously had been produced by

fission similar to that already observed within doors. One of

these fragments which was larger than the others had partly

curled together and on the next day the ends had come in contact

and two tiny prominences, apparently the beginnings of tentacles,

had appeared.

On examination of this same tidepool at various times since then,

like fragments have always been found. They showed generally

neither tentacles nor mouth, and their irregular, elongate shape,

not having taken on the radiate form, also their brownish color,

: Since writing the above paper, my attention has been called to A. Andres’

publication “Intorno alla scissiparita delle attinie,” (Mitteil. Zool. Sta. Neapel,

vol. 3, pp. 123-148). My observations were made without any previous

knowledge of those of Professor Andres or of any other naturalist. They

were also made on a different species. Moreover, my figures show three points

not illustrated by Professor Andres, or to my knowledge, by any other author-

ity: first, oral views of successive stages of development of the young pro-

duced by fragmental fission (laceration) showing the completion of the curling

process by which the young assumes the parent form; second, serial, trans-

verse sections of parent and young in process of fragmental fission showing

the infolding of the body wall preceding the separation of the two; third,

diagrams illustrative of the process of such fission.

No. 476] FISSION IN METRIDIUM 585

distinguished them from the transparent young developed from

the ovum."

The Trembley experiments previously performed on the hydra

suggested the pursuance of the same method with Metridium

marginatum, hence on Wednesday, June 15, 1898, at 2 P. m., the

fragment figured at Plate 1, Fig. 1, was produced by artificial

fission from the base of a specimen one fourth of an inch in diam-

eter. The Metridium threw out one acontium near the mouth :

and several where it was cut, and drew in its tentacles entirely.

When cut off the fragment fell to the bottom of the glass as if it

were without life, and had to be turned over with a needle so as

to rest on its base. This fragment was kept under careful obser-

vation every day for a period of three weeks and, from studies

taken from time to time, the accompanying drawings were made.

The lines crossing Fig. 1 (Pl. 1) nearly at right angles to its

length represent portions of the radiating mesenteries of the par-

ent form as seen through the body.

At 2.15 P. m. of the same day the Metridium had extended its

tentacles, and in the fragment, as seen in Fig. 2 (Pl. 1), the extrem-

ities were approaching each other.

Fig. 3 (Pl: 1), drawn at 4.30 P. m. of the same day, shows a nearer

approach of the ends and a difference in size, whether due to

growth or to the re-assertion of the power of expansion possessed

by the normal animal.

In Fig. 4 (Pl. 1), drawn Tuesday, June 21, at 2 P. M., is seen

a greater elevation of the column and a more spreading base,

although the ends have not yet joined.

In Fig. 5 (Pl. 1) drawn on Wednesday, June 22d, at 10 a. M.,

the extremities of the fragment have come together, thus producing,

approximately, the normal radiate structure of the sea anemone,

leaving, however, a slight inward curvature at the point of junc-

! Since the above observations were recorded, a number of these fragments,

already beginning to curl together, have been carefully collected and placed

in a jar where the successive stages leading to their maturity have been fol-

lowed. They have been found to develop in essentially the same way as did

the artificially produced fragment described farther on. The ends of one

unusually long fragment curled in opposite directions. Could this latter

suggest the origin of many of the double-mouthed Metridia found?

586 THE AMERICAN NATURALIST [Vor. XL

ture. The base here is a trifle more extended and the column,

as shown in Fig. 6 (the side view of Fig. 5), is much more elevated.

On Thursday, June 23d, at 11.30 a. m., Fig. 7 (Pl. 1) was drawn.

Here the young form shows translucent prominences afterwards

recognized as the beginnings of tentacles, the one at the line of

juncture being less developed than the others. This line of junc-

ture is still visible up as far as the tentacles and makes a slight

irregularity at the base. The mouth could be discerned but

faintly at this time.

Fig. 8 (Pl. 1), the side view of Fig. 7, shows the tentacles more

plainly.

Fig. 9 (Pl. 1), represents the young form as it looked on Saturday,

June 25th, at 3 p.m. It shows a further development of tentacles

and mouth and an increase in size.

In Fig. 10 (Pl. 1), the side view of Fig. 9, the line of juncture is

seen to have disappeared throughout the upper third of the column.

In Fig. 11 (Pl. 1), drawn on Saturday, July 2d, the hour not noted,

this line is still fainter and shorter and a further increase in the

size of the animal is indicated. At this time the young Metridium

was very active, crawling along the glass at the edge of the water.

Ten tentacles were visible, unequal in size. Lack of symmetry

is especially noticeable here and in the following figure. This

same lack of symmetry holds in all observed forms which were

produced by fragmental fission. Whether these forms ultimately

become symmetrical is not known to the writer.

Fig. 12 (Pl. 1), was drawn on Wednesday, July 6th, just before

the young Metridium was put into formalin. This shows a further

growth and a development of two more tentacles, making twelve

tentacles in all.

Thus in the three weeks, from Wednesday, June 15th, to Wednes-

day, July 6th, a fragment from the base of a small Metridium

marginatum curled together until its extremities met, developed

a spreading base, a column, twelve tentacles, and a mouth, and

must therefore have performed the nutritive functions, as evidenced

also by the increase in the size of the animal. This experiment

of artificial fission was repeated several times on other Metridia

with similar results.

During the examination of mierotome sections of small Metridia

No. 476] FISSION IN METRIDIUM 587

at about this time, for the purpose of studying the microscopic

structure of the animal, one Metridium revealed the serial sections

figured in Plate 2. These figures are slightly diagrammatic, as

intended to illustrate merely the point under consideration. From

a study of these sections, if the above observation of reproduction

by artificial fragmental fission be borne in mind, the inference

may be drawn, that at the time of killing, the Metridium from

which the sections were taken was preparing to reproduce asex-

ually by cutting off a fragment.

In Fig. 1 (Pl. 2), either the cutting was not parallel to the oral

dise, or the column was unevenly distended vertically, as the

tentacles are seen on but one side, that opposite to where fission

takes place. This is also noticed in sections shown in Figs. 2 and

3 (Pl. 2). The same fact was noted in regard to similarly placed

serial sections of other Metridia examined, which were reproducing

in the same way.

In Fig. 1 (Pl. 2), the uppermost in which fission is visible, the

separation between parent and fragment is seen to be complete.

Portions of the old mesenteries reaching from the outer to the inner

body wall are visible in this section in the young.

In Fig. 2 (Pl. 2), the fragment cut off is longer than in section

1, but the separation between the two is not quite complete.

In Fig. 3 (Pl. 2), the infolding of the body wall which makes

the division between parent and fragment is not continuous as in

sections 1 and 2. The break is seen toward that extremity of the

body where the tentacles are visible. This break in the conti-

nuity of the fold in the section may be due to a slight irregularity

in the folding. No separation between parent and fragment, such

as was seen in sections 1 and 2, has as yet taken place. The frag-

ment here cuts off a greater proportion of the parent body than in

the section before considered. It is also wider and shows longer

mesenteries. Bilateral symmetry is here evident in the parent

after the infolding of the body wall which is to cut off the fragment.

This same fact is noticed in sections of other Metridia in which like

fission is taking place.

In Fig. 4 (Pl. 2), the dividing fold is seen pushing inward from

either side, evidently about to cut off here a still larger proportion

of the parent than in Fig. 3. It will be noticed here, where the

588 THE AMERICAN NATURALIST [Vor. XL

ends of these folds are as yet far from meeting that, previous to

fission, there has been an increase in size on the side where this is

to take place. This seems to be in accordance with the general

rule that extra growth usually precedes fission.

Fig. 5 (Pl. 2), shows the folding of the body wall extending

inward but little from either end. One of these folds shows new

mesenteries growing from the side which is to form the inner sur-

face of the body wall of the parent. In this section the fact is still

more apparent that, before fission occurs, the parent form lacks

bilateral symmetry and that the division takes place on the larger

side.

The same is seen in Fig. 6 (Pl. 2), which shows only the begin-

nings of the inward foldings of the body wall, after the completion

of which the parent form is to be approximately symmetrical.

In the other sections between that shown in Fig. 6 and the base

or pedal disk, the same conditions hold with regard to lack of sym-

metry as related to the side upon which fission takes place. The

body wall shows no inward folding here, but judging from the

artificial and natural fission observed, the folding would eventually

have reached the base.

In all the sections shown, the line a. b. passing between the two

pairs of directive mesenteries, d. m., represents the plane of sym-

metry of the parent animal. The fragment is seen to be divided

off on one side only of this plane.

The study of serial sections of other Metridia showed the com-

plete and the partial infolding of the body wall essentially like the

above, and evidently preceding fragmental fission.

In consideration of the facts as observed and stated above, the

following conclusions are reached by the writer as to asexual

reproduction in Metridium marginatum by fragmental fission.

This occurs in nature as observed in the jar within doors and as

seen in the tidepools; also as indicated by the sections. It occurs

frequently, as shown also by observations on tidepools.

From the study of sections it is inferred, that the body becomes

bilaterally asymmetrical before fragmental fission takes place,

this occurring always, as far as observed, on the larger side and

that the fragment thus cut off includes body wall (formed on the

side next the parent by infolding of the parent body wall), and

No. 476] FISSION IN METRIDIUM 589

parts of directive and other mesenteries on one side only of the

plane of symmetry of the parent animal. The sections show also

that the infolding of the body wall proceeds gradually, and simul-

taneously downward and inward from the top and upper part

of the sides, and that separation of the fragment from the parent

commences at the top, as indicated by diagrams (Figs. 7 and 8,

PE 2).

This infolding of the body wall here, to separate the fragment

from the parent form, seems to be essentially the same process

as the constriction which divides the Hydra bud from its parent,

but here the basal attachment modifies the process by preventing

the infolding on that side and by keeping the fragment close to

the parent until separation is complete. Whereas in Hydra, a

thread tied between parent and bud would represent the method

of division, in Metridium the thread may be imagined as held

down at either side of the pedal disk and gradually tightened

along the line which is to separate parent from fragment, thus

producing an infolding proceeding downward from the top and

inward from the upper part of the sides.

Observations of the young naturally and artificially produced

by fragmental fission show that the fragment cut off curls together

until its extremities meet, making parts of mesenteries before

nearly parallel now radial in arrangement, thus attaining to the

sea anemone structure with the least possible expenditure of

energy. From artificial fragmental fission principally, it is seen

that the base or pedal disk spreads for attachment, the column

becomes elevated, the line of juncture tends to disappear, mouth

and tentacles develop, and growth in volume apparently takes

place; that the young thus produced, possesses the power of loco-

motion and that it is, in fact, a whole organism, and, except for

the fact that it has not yet attained symmetry, is essentially, in

outward appearance at least, a smaller reproduction of its parent.

Obligations are due to Dr. A. G. Mayer for reading this paper,

to Mrs. J. M. Arms Sheldon for valuable suggestions, and to

Professor G. H. Parker for the determination of specimens; also

to the artist, Mrs. A. M. Dodge, for faithful delineation of speci-

mens and sections.

590 THE AMERICAN NATURALIST [Vor. XL

PLATE 1.

No. 476] FISSION IN METRIDIUM 591

PLATE 2.

NOTES AND LITERATURE

ZOÖLOGY

Plankton of Northern Seas.'— The earlier parts of this series of

monographs (see this journal, vol. 39, p. 341) have been supplemented

by two additional sections containing six more papers dealing re-

spectively with the pelagic annelids, cheetognaths, Rotatoria, Acan-

tharia, Radiolaria (Acanthometrida), diatoms, and a portion of the

pelagic eggs and larve of the fish of northern seas, that is of water

north of 50° N

The papers on the pelagic annelids and the chetognaths are

necessarily brief, the former including only nine, and the latter but

seven species. Dr. Strodtmann follows Krumbach in making use

of the grasping teeth of Sagitta as diagnostic characters for specific

distinctions. ‘The pelagic rotifers are somewhat more fully treated

by Dr. Lauterborn. As yet the marine rotifers are very incompletely

known, except in the Baltic and North Seas. Only sixteen marine

and brackish water forms have as yet been found in northern waters.

About forty additional species of fresh-water rotifers are known to

enter the seas but they are adventitous and do not become acclimated

to the marine habitat, except in a few cases, in which marine varieties

of fresh-water species are known, as for example in Anure@a aculeata

var. platei, and A. cochlearis var. recurvispina. The marine species

are all coastal or brackish-water forms, none being known as yet

from the high seas.

Dr. Popofsky’s monograph of the Acantharia (sublegion Acan-

thometra) will be especially welcome as it embodies the revision which

he has recently completed of this group, the first to be made since the

publication of Haeckel’s monograph of the Radiolaria. The author

1 Nordisches Plankton. Herausgegaben von Prof. Dr. K. Brandt und Dr.

C. Apstein. Dritte Lieferung. M. 10. X. Anneliden, J. Reibisch, 10 pp.,

15 figs.; Die Chetognathen, S. Strodtmann, 8 pp., 11 figs.; Nordische Plank-

ton, Rotatorien, R. Lauterborn, 25 pp., 17 figs. XVI. Die nordischen

Acantharien. I. Teil and Nachtrag, A. Popofsky, 27 pp., 20 figs. XIX.

Diatomeen, H. H. Gran, 146 pp., 178 figs. Vierte Lieferung. M. 10. II.

Eier und Larven von Fischen, I. Teil, E. Ehrenbaum. Kiel und Leipzig, 1905,

large 8vo. 216 pp., 82 figs.

593

594 THE AMERICAN NATURALIST [Vor. XL

takes a justly conservative ground in the matter of species in this

group and is much inclined to question the reported occurrence of

certain forms in northern waters. He notes the solubility of the

skeletal structures (calcium-aluminium silicate or hydrate) in acids,

alkalis, sea water, or distilled water, and rejects species founded on

“skeletlos” specimens.

Professor Dr. Gran's treatment of the diatoms of the plankton will

be most welcome to all planktologists, for no comprehensive mono-

graph of these organisms has appeared since that of Castracane in

the Challenger Reports, and this unfortunately is far from complete.

The more recent investigations, especially of Schütt and Cleve, have

added greatly to our knowledge of the pelagic genera, but this revival

of interest has been attended by considerable duplication and con-

fusion in synonymy. The authors wide experience with these

organisms makes his critical monograph most timely. The mono-

graph includes nearly 300 species, most of which are figured. Ex-

cellent keys to both genera and species are found throughout the paper.

It is perhaps desirable that the chromatophores should be more com-

pletely utilized in the description of species and that their position in

the cell should be interpreted with reference to the vertical distribu-

tion in the sea and consequent exposure to light.

The first section of Dr. Ehrenbaum’s account of the eggs and larve

of the northern fishes found in the plankton includes nearly ninety

species from about thirty families ranging from the Labride to the

Pleuronectidz. Although it does not include some families of greatest

economic importance in northern seas, as for example the Clupeid:ze

and Gadidee, this first part nevertheless contains much of interest

along economic and fish-cultural lines. The young of nearly all, and

the eggs and larve of many fishes are taken in the plankton. The

pelagic habit is, however, of little syst

young of species of the same genus are in some instances pelagic, in

others benthic in distribution. The author notes the significance of

dimensions and pigmentation as diagnostic characters of the young

and urges the importance of the examination of living material.

Preserved eggs and larve, even in the best condition

determined. The size of the eggs, and

ules, and the number of fin-rays

vertebree, are subject to considerable variation.

the range of this variation increases

species, and with the length of the

The author's account is abun

ematic significance since the

It is noteworthy that

with the area of distribution of the

breeding period under observation.

dantly illustrated with over three

No. 476] NOTES AND LITERATURE 595

hundred figures many of which are original. The excellent work of

the Helgoland Station is evident on many of the pages of this com-

prehensive report.

The authoritative character of the papers in this series insures for

them a wide range of usefulness and a permanent value to all natur-

alists who are concerned with the pelagic life of the sea.

C. A. K,

Notes on Pennsylvania Fishes. Notropis cayuga Meek.— Early

» in August of 1904 I secured a single example of this minnow in the

Allegheny River, above Port Allegany, in McKean County. This

is, I believe, the first record within our limits. Other fishes noted

from this locality were Lampetra wilderi, Salvelinus fontinalis, Campos-

toma anomalum, Semotilus atromaculatus, Leuciscus elongatus, Rhin-

ichthys atronasus, Catostomus commersonnii, C. nigricans, Erimyzon

sucetta oblongus, Schilbeodes insignis, Esox vermiculatus, Ambloplites

rupestris, Eupomotis gibbosus, Micropterus dolomieu, Boleosoma nigrum,

and Uranidea gracilis. In the summer of 1899 I noted Polyodon

spathula, Campostoma anomalum, Leuciscus elongatus, Notropis

hudsonius, N. whipplei, N. cornutus, Rhinichthys atronasus, Sti-

zostedion vitreum, and Boleosoma nigrum from streams near Cole

Grove and other places along the Allegheny.

In the Susquehanna tributaries in Cameron County during October

of 1905, I noted Lampetra wilderi (apparently this species though I

did not see it myself), Semotilus atromaculatus, Leuciscus vandoisulus,

Brama crysoleucas, Notropis cornutus, Rhinichthys cataracte, R.

atronasus, Exoglossum mazillingua, Catostomus commersonnü, C.

nigricans, Schilbecdes insignis, and Boleosoma nigrum olmstedi. All

these species occur near Emporium. Notropis amenus occurs near

Paradise, in Lancaster County, where I have received it from Mr.

J. S. Witmer.

Mesogonistius chetodon (Baird).— The only place where I have

found this sunfish in Pennsylvania has been in the basin of Mill Creek

in Bucks County, near Bristol. It seems to occur sparingly, and most

all of my examples were secured in the colder months. I have not

found any previous definite records for Pennsylvania.

Boleichthys fusiformis (Girard).— I have only found this in the

same locality as the former in our State. The first example was se-

cured July 23, 1905, and on December 24 of the same year I

found it very abundant. Though known from the lower tributaries

of the Delaware in New Jersey, this fish has never before to my knowl-

596 THE AMERICAN NATURALIST [Vor. XL

edge been taken in Pennsylvania. The conditions where I secured

my examples were similar to those found about Crosswicks Creek

near Trenton, where the species is more or less abundant, though

perhaps not so characteristic as in the lower lands. On the latter

date Anguilla chrisypa, Notropis chalybeus, Brama crysoleucas,

Erimyzon sucetta oblongus, Esox americanus, Umbra pygmea, Shilbe-

odes gyrinus, Aphredoderus sayanus, Enneacanthus gloriosus, the

above mentioned Mesogonistius, Eupomotis gibbosus, the above

Boleichthys, Aromochelys odoratus, larval Desmognathus, Cambarus,

larval dragon-flies, and hosts of Crustacea and shrimp, Gammarus,

were also taken.

Enneacanthus obesus, contrary to Cope’s statement that it is rare,

is fairly abundant in southeastern Pennsylvania, though apparently

local. I have received many living examples from the “Neck” in

the lower part of Philadelphia.

Henry W. FOWLER

Note on Muhlenberg’s Turtle.— While spending a few days in

late April with Mr. T. D. Keim in the region of Cedar Swamp Creek,

Cape May Co., N. J., we observed a number of turtles about the fresh-

water pools at the edge of the salt-marsh near Palermo. A single

example of Clemmys muhlenbergi was found in this locality, a fact of

some interest as the species does not seem to have been noted from

southern New Jersey before. As an upland animal its distribution

may be explained to some extent by the appearance of Calopeltis

obsoletus at Stone Harbor, recorded by Mr. Witmer Stone in this

journal for 1906, p.166. In fact, most of the narrow strip on the Cape

May County seacoast shows traces of upland life, the intervening

cedar-stained streams presenting usually peculiar features. Kino-

sternon pennsylvanicum, Chrysemys picta, and Clemmys guttatus were

abundant as noted in sequence. Chelydra serpentina and Terrapene

carolina were also found, together with Natrix sipedon, Thamnophis

sauritus, Rana pipiens, Hyla pickeringii, Acris gryllus crepitans, and

Bufo lentiginosus.

Henry W. FOWLER

No. 476] NOTES AND LITERATURE 597

ANTHROPOLOGY

The Bontoc Igorot' is a well written and abundantly illustrated

contribution to the ethnology of this interesting branch of the Malay

people. ‘The work is the result of the author's eight and a half months’

stay among the Bontoc and other divisions of the tribe. It embraces

a geographical and a historical sketch of the Igorots, notes on their

physical characters and pathology, and descriptions of their social

life and organization, economic life, political life, war and head-hunt-

ing, esthetic life, religion, mental life, and language.

The word Igorot means “ mountain people.” The several branches

of the tribe occupy northern Luzon, north of the 16th degree of north

latitude. They are estimated collectively at from 150,000 to 225,000.

The principal dialectic groups are Tinguian, Kalinga, Bunayan,

Isanay, Alamit, Silipan, Ayangan, Ipukao, and Gadan. The Bontoc

Igorots are so called after their principal village and the province.

The Bontoc Igorot (represented at the Louisiana Purchase Exhi-

bition in 1904) is “a clean-limbed, well-built, dark brown man of

medium stature." The men average 1.60 m. (5 ft., 44 in.) in height

and are prevalently mesocephalic and mesorhynic. They are never

corpulent and seldom thickset, their bodies being generally well formed

and symmetric. The hair is black and straight, and the eyes brown.

The women average 1.46 m. (4 ft., 9% in.) in height and more among

them show a tendency to brachycephaly. The detailed description

reads much like that of the American Indian and it is remarkable how

many of those pictured in the book approach types often seen among

the Indians.

The people are very primitive and wear but little clothing. Their

principal occupation is agriculture. They are industrious, the social

life is lowly, marriages are monogamous. “The social group is decid-

edly democratic; there are no slaves." There are but a few vices.

The religion is animism and spirit belief, with the idea of one god.

In disposition the people are kind and not servile. They are trust-

worthy. They possess a good sense of humor. The children are

bright and learn quickly. The author has the best hopes for the future

of the people.

‘Jenks, A. E. The Bontoc Igorot. Ethnological Survey Publications, Vol.

I, Manila, 1905.

598 THE AMERICAN NATURALIST [Vor. XL

The work is full of interesting details. The illustrations are mostly

reproductions of very good photographs. Possibly it would have been

better if the 154 plates had been bound separately; it would make the

book easier to handle.

The creditable volume of Mr. Jenks leaves the earnest desire that

it may be followed by a thorough physical and physiological study of

the same people.

A H.

Notes.— Origin of the Slavs. A comprehensive article (Zaborowski,

“Origine des Slaves,” Bull. et Mém. Soc. d’ Anthrop., Paris, ser. 5,

vol. 5, no. 6, Dec., 1904, pp. 671-720), in which the well known

author sums up his investigations. The original country of the Greeks,

Umbro-Latins, Gauls, and Germanic peoples was treated of previously.

All these groups do not appear in history at the moment of their separa-

tion from'their proto-Aryan territory; but they can be followed nearly

to the limits of this region.

The Greeks were the first to gain their historic possessions. Their

migration is lost in the obscurity of time. They occupied, in all prob-

ability, a part of the territory northeast of the Adriatic, living in those

neolithic villages characterized by abundance and great variety of

artistic pottery, such as that of Butmir, near Serajewo, Bosnia.

The Umbro-Latins, coming from the northeast, can be well studied

in the remains of their habitations known as ferramares, in the pro-

vinces of Emilia and Marches, northeastern Italy. They were still

at that time in close relation with the proto-Aryan people of the

Danube.

'The home of the proto-Gauls was adjacent to and partly blended

with the proto-Aryan region. It was located, as is known with

certainty, along the upper Rhine and upper Danube, and extended

thence to more or less determined limits northward and eastward.

The original proto-German country the author places, on the basis

of archeologic and even historic data, in the lands west of the Baltic,

where these people lived since at least the neolithic period.

To determine the exact origin of the Slavs is more difficult. The

earliest historic accounts show them already spread over vast spaces

and over regions very distant from one other. The hypotheses that

they came as they were from Asia, or were identical with the Sara-

mates, are untenable. The most creditable sources all refer their

origin to the Danube (especially lower Danube region). Their lan-

guage, belonging to the satem group, could not have originated except

No. 476] NOTES AND LITERATURE 599

in the zone east of the proto-Aryan territory. The linguistic an-

cestors of the Slavs spread over the Danube basin when the Umbro-

Latins and Greeks on one part and the Gauls on the other were draw-

ing away from it, or had abandoned it. They came after these peoples.

It is now known that the Illyrians, Pannonians, Dacians, Moesians,

and Gétes were all Slavs. Originally, the Illyrians appear to have

been one of the proto-Aryan peoples, but this element among them

was eventually displaced by that which is characteristic of the Slavs.

The introduction of this new element is believed to have been due to

the Paphlagonians, and to have taken place after the Trojan war,

or during the twelfth century B.C. The Paphlagonians were the

neighbors of the Cappadocians in Asia Minor, and related to the

proto-Armenians and Medes. They aided Troy and after its fall

are supposed to have passed to Thrace, adopted the language of the

Thracians and Illyrians, and mixed with these. They were people of

dark complexion, with a rather short nose and brachycephalic; and

they cremated their dead. "The first Slav political unit appears as the

Venedes, or Venetes. This people penetrated to the northeastern

regions of what is now Italy. Their type and in a few localities even

the Slavonic language are still found in these regions. From this

locality they spread, still many centuries before Christ, northward

and northeastward, to Bohemia, to beyond the Carpathians, Vistula,

Dniester, and up to the Baltic. They founded Vindobona (Vienna)

and their name persists with modifications in a number of localities.

(and as a name of a Slavonic people, the Wends), to this day.

Wherever they went up to the time of christianization (8th to 12th

century of our era) they practised incineration of their dead, and

theirs is the industry known in archeology as that of Hallstadt.

For many interesting details the reader must be referred to the

original.

A. H.

600 THE AMERICAN NATURALIST [Vor. XL

BOTANY

Plants and Light.'— A paper of Professor Julius Wiesner, dealing

with the quantitative and qualitative light-relations of plants, is of

particular interest to American botanists, since it records the results

of observations made in the United States.

Some twelve years ago, Professor Wiesner, who fills the chair of

‘plant physiology at the University of Vienna, led by his studies on the

relation of light-intensity and heliotropism on the one hand, and that

of light-intensity and carbon-assimilation on the other, inaugurated a

series of observations on the effect of light-intensity on the form of

plants. The discovery that the process by which the plant assumes

its form depends on the influence of rays different from those which

take part in photosynthesis, opened an entirely new field of investi-

gation, and rendered the measurement of the highly refractive rays

a necessity.

Various methods answering the latter purpose existed, the principal

one being that of Bunsen and Roscoe, in which a standard photo-

graphic paper is exposed to light; the tone obtained is then compared

with a standard black. In the course of the investigations various

improvements in the method, such as a substitution of a color-scale

for the standard black, suggested themselves. Detailed accounts of

method and improvements are scattered through Professor Wiesner’s

numerous papers, but may be found more especially in his earlier

publications.”

These measurements of light-intensity are based on the law of Bun-

à 1 ' Wiesner, J. ee n pocung über den Lichtgenuss der Pflanzen im

Yellowstone Gebiete und in anderen Gegenden ordamerikas. Photometrische

Xnternchungen auf pflanzenphysiologischem Gebiete. (V. Abhandlung.)”

Suzungsber. d. k. Akad. d. Wiss. in Wien, mathem.-naturw. Klasse, vol.

114, pt. 1, Feb., 1905.

* Wiesner, J. “ Photometrische Untersuchungen auf pflanzenphysiologi-

schem Gebiete. (I. Abhandlung.)" Sitzungsber. d. k. Akad. d. Wiss. in

Wien, mathem.-naturw. Klasse, vol. 102, pt. 1, June, 1893; and “ Unter-

suchungen über den Lichtgenuss der Pflanzen mit Rücksicht auf die Vegeta-

tion von Wien, Cairo und Buitenzorg (Java). Photometrische Untersuchun-

gen auf pflanzen physiclogischenm Gebiete. (II. Abhandlung.)" Sitzungsber.

d Akad. d. Wiss. in Wien, mathem.-naturw. Klasse, vol. 104, pt. 1,

July, 1895.

No. 476] NOTES AND LITERATURE 601

sen and Roscoe: “Identical colors of normal papers exposed to light

indicate identical products of light-intensity and time.” Any tone

may therefore be produced by any intensity, but reduced to a definite

time, can correspond to one definite (chemical) light-intensity only.

For purposes of measurement of chemical light-intensity, a darken-

ing of the normal paper corresponding to the normal black and brought

about in one second, is considered as the unit. If, for instance, the

normal black is obtained on the normal paper in 2 seconds, the light-

intensity equals 4.

By aid of this method, the light-intensity at any place, on plains,

in the vicinity of buildings or groups of trees, inside of the tree-crown,

in the shade, in greenhouses, in rooms, etc., can be measured. One

can determine the part of the total daylight at by a plant (“rela-

tives Lichtgenuss’’), and compare this with the amount of light which,

on standard paper, forms the normal tone in one second (“absolutes

Lichtgenuss"). In this manner the relation between light-intensity

and bud development, form of plant-body, budding and the shedding

of leaves was determined. It was found that certain trees use more

light than do others, that the portion of total daylight used by trees

varies with the time of day, that for some trees this portion is greatest

at noon, that for others it is least at the same hour.

Observations were made in Central Europe chiefly, but at times

extended to 6? S. lat. and 79° N. lat. This included plains and moun-

tain ranges in temperate climates (Central Europe), arctic regions

(Spitzbergen), tropical (Java), and semitropical regions (Egypt).

The extension of the experiments to high altitudes remained, more

particularly a study of the change in relation between light-intensity and

the amount of light used by the plant under the influence of increased

altitude.

The mountainous regions of Europe do not offer a desirable field for

such investigations, on the one hand because the tree-limit is reached

comparatively soon, on the other because extensive plateaus at a

considerable elevation above sea-level and easy of access, are lacking.

Besides, on account of the numerous cafions and resulting sheltered

and exposed places, introducing a vegetation of other altitudes,

mixed with regressions, and causing a descent and ascent of species,

the continental mountain ranges do not recommend themselves for

this purpose.

The extensive American plateaus, however, offer the advantage of a

gradual slope from the Atlantic to the Rocky Mountains. This is

true in particular of a region beginning with the Missouri valley and

602 THE AMERICAN NATURALIST [Vor. XL

ending at the head-waters of the Yellowstone. One of the chief advan-

tages which this section offers for photometric investigations lies in

the very gradual rise of the ground from east to west, beginning with

an elevation of but a few hundred meters and finally attaining a height

of more than 3000 meters.

Professor Wiesner made use of these natural conditions when, in

1904, he visited the United States. Measurements were made at vari-

ous points, such as Niagara, St. Paul, Colorado Springs, and Pike’s

Peak, but the main part of the investigation was carried on in, or in the

immediate vicinity of, the Yellowstone Park, during the latter part of

August and the early part of September. The medium for study was

afforded by 24 herbaceous and 17 woody species.

It was found that an increase in altitude not only means an increase

in the intensity of the total daylight, but also an increase in the

intensity of the direct (parallel) rays as compared to the intensity

of the diffused light. Earlier work! had shown that the amount of

total daylight used by arctic plants increases as they approach the pole.

Measurements in the United States showed that plants ascending

to higher altitudes behave in the same manner, but only up to a certain

altitude, beyond which a constantly diminishing portion of the total

light is used. Evidently the increased intensity of the direct sunlight

in high altitudes is not favorable to trees, as shown by the fact

that plants, which at lesser elevations do not shed their leaves in sum-

mer (Hitzelaubfall), do so at greater altitudes.

protection against the very intense direct rays is found in the

cypress- (pyramid-) shape, adopted by trees in high altitudes (Pinus

murrayana in the Yellowstone Park). Thus the rays of the midday

sun strike the tree at a small angle and hence become much weakened

before penetrating the crown. Trees which reach down as far as sub-

tropical regions also have a pyramid-shaped crown, as for instance the

cypress, and for the same reason, since this shape protects the trees

from the too intense light from the south.

These investigations open a comparatively new field which those

who live under favorable conditions will doubtless hasten to enter.

The various agricultural experiment stations, for instance, could

easily take up such work. In a few years there would be produced

'Wiesne “Untersuchungen über den Lichtgenuss der Pflanzen im

sited ne Photometrische Untersuchungen auf gg saat

schem Gebiete. (III. Abhandlung.)” Sitzungsber. d. k. Akad. d. Wiss.

Wien, mathem.-naturw, Klasse, vol. 109, pt. 1, 1900.

No. 476] NOTES AND LITERATURE 603

an accumulation of figures the interpretation of which would be of

both scientific and practical value, being applicable to physiological

and horticultural problems alike.

H. Hus

Campbell’s Mosses and Ferns.'— This new edition of a widely used

work is so much enlarged and revised as to deserve recognition as

such on its title page, rather than to have it announced only in the

" Preface to the Second Edition." The extent of the new matter is

shown in the increase of the fourteen chapters constituting the body

of the former book, by 54 pages, the addition of two entirely new

chapters containing about 29 pages, and the increase of the text

figures from 266 to 322. The great activity of investigators in this

field during the ten years since the first edition was issued, is indicated

by the addition of about 189 titles to the bibliography, while some

papers referred to in the new text appear to be omitted from the list.

The portion of the text devoted to the Bryophyta is not greatly

modified. The changes consist chiefly in the suppression of a few

sentences here and there, and the occasional addition of a paragraph

or two; e. g., there is a new account of the spermatogenesis of Mar-

chantia based on Ikeno’s work. The most striking change is the

tee of the Anthocerotacex from the rank of a subordinate

roup” under the Hepatice to that of the Class Anthocerotes

coórdinate with the Hepatic® and the Musci. This view is not new,

for the same disposition of the group was formally made by Howe in

1899, and was followed by Professor Campbell in his University

Text-book (1902), though neither in the latter work nor here does the

author mention the fact. Little new evidence on this question is now

brought forward, for the increase in the space devoted to the Anthocer-

otes is due chiefly to the addition of three new figures. The change

has come about through the giving of greater weight to the well known

peculiarities of the group, and it is to be welcomed as emphasizing

the importance of these plants in phylogeny. It is a pleasure to note

that the author has at last begun to adopt a consistent plan of designat-

ing orders and families in accordance with the best present usage,

though it is unfortunate that he still clings to the clumsy and anomalous

terms Jungermanniales Anacrogyne and J. Acrogyn®. Incidentally

‘Campbell, D. H. The Structure and Development of Mosses and Ferns

(Archegoniate). New York, The Macmillan Co., 1905. Svo, vii + 657 pp.,

illus.

604 THE AMERICAN NATURALIST [Vorn XL

it might be remarked that the author perpetuates an error of the first

edition in stating that Underwood, in substituting for the above terms

the names Metzgeriacez and Jungermanniacez, regarded these fam-

ilies as divisions coördinate with the Marchantiales and Anthocerotes;

the latter writer in fact, considered the whole group of the Junger-

manniales as of equal rank with the Marchantiales.

In the portion devoted to the Pteridophyta, there is not such a con-

sistent use of the proper ordinal terminations, and the lack of indica-

tion as to the rank of the different groups in the main headings will

cause much unnecessary trouble for the student who wishes to get

a general view of their relative position in classification. The most

important change in this section is the removal of the Isvetacex

from the eusporangiate ferns to a position after Selaginella. There

will doubtless be general acceptance of the view that this group is

sufficiently distinct to warrant the establishment of a separate order

Isoetales; perhaps it might better be regarded as forming a distinct

class. It is to be inferred that this may be considered Order II under

the Class Lycopodines (as in the University Text-book), but the

author makes no statement on this point, and his rather detailed

emphasis on the facts pointing to “a real, but extremely remote

relationship between Isoetes and the Eusporangiate”’ may leave the

student in doubt as to why this genus is generally connected with the

Lycopods. There are many important additions to text and illus-

trations, particularly in such recently investigated forms as Botrychium,

Selaginella, and Isoetes.

One of the new chapters, on “The Nature of the Alternation of

Generations,” champions the antithetic theory with the same general

argument as that advanced by Professor Campbell in the American

Naturalist in 1902; he considers that the advocates of the homologous

theory have not furnished sufficient evidence to substantiate their

view. Here as well as elsewhere, the author gives some prominence

to Coleochzete as the probable ancestor of the bryophytes. The recent

investigations of Allen on chromosome reduction in this genus indicate,

to say the least, that it is much further removed from the bryophytes

than has been supposed. We should be unwilling to say there is no

alternation of generations in Coleochete; but if the phenomena of

uction are to be made the chief means of interpretation, the

sporophyte is undifferentiated, consisting only of the fertilized oöspore,

while the first four cells produced in its germination, or possibly the

mass of loosely connected cells, may bear a remote comparison to the

spores of mosses. Certainly the view held by .Campbell and others

No. 476] NOTES AND LITERATURE 605

that the zoöspores produced by these cells are homologous with the

moss spores was not rational; for that zoöspore production is only

one method of germination of these cells, depending upon accidental

conditions, is proved by the fact that they may grow out directly into

filaments, as shown by Chodat and others.

The other new chapter furnishes a convenient but necessarily brief

and incomplete réswmé of the fossil Archegoniates. In the concluding

chapter, the author holds mainly the same views as previously: he

is inclined to believe that the Spermatophyta are polyphyletie in

origin, since the Conifers show the greatest resemblance to the Lycopo-

dinez, and the Cycads to eusporangiate ferns (through the Cycado-

filices); while the Monocotyledons may possibly be derived from

aquatic ancestors resembling Isoetes, and the Dicotyledons from the

Monocotyledon stock.

There are numerous paragraphs in the first edition where the

language is obscure, and we have hoped in vain that these might be

made more clear for the benefit of the student who can ill spare time

to dig out their meaning. Nevertheless in spite of these and some

other defects which might have been remedied without very great

labor, it must be said that Professor Campbell has given us a much

improved and more usable edition of a valuable book.

T. E. Hazen

Common and Conspicuous Lichens of New England’ is the title

of a series of booklets by R. H. and M. A. Howe. The descriptions

are accompanied by some very good photographic reproductions of the

lichens in their habitats, as well as by line drawings of the thallus.

The work is being issued in parts. Part I contains twenty-two pages;

Part II, eighteen pages. The following genera are described in the

first two parts — Ramalina, Cetraria, Evernia, Usnea, and Alectoria.

H. S. R.

Czapek’s Biochemistry of Plants? — Each year witnesses an

increasing interest in the study of biological chemistry. As time goes

on the work becomes broader and yields more results. Until recently

the subject would have perhaps been more aptly designated as zoó-

' Howe, R. H., Jr., and M. A. Common and Conspicuous Lichens of New

England; a Fieldbook jor Beginners. Boston, W. B. Clarke and Co., 1906.

16mo, Parts 1, 2, 40 pp.

*Czapek, F. Biochemie der erg Jena, Bd. 1, 8vo, pp. xv+584,

1904; Bd. 2, 8vo, pp. 1186,

606 THE AMERICAN NATURALIST [Vor. XL

chemistry, since most of the investigators busied themselves with the

physiological chemistry of animals. Indeed, the term physiological

chemistry itself is usually understood to deal with the study of animal

tissues. Happily, this field which has yielded so richly to the zoölo-

gists, is beginning to be explored more widely by the botanists.

The appearance of Czapek’s work marks the beginning of an epoch

which should mean much for future work in plant physiology and,

indeed, in all other lines which are in any way concerned with the

chemistry or physiology of the plant. The author is a well trained

botanist, physiologist, and chemist. He gives the reader a truly

broad and modern view of the subject in hand, the book being in all

senses of the word a biological chemistry of plants, not a chemistry of

plant organs or plant products. Throughout the entire work, we

find the literature on every subject summarized and brought down to

date with almost unparalleled accuracy and completeness.

The first volume opens with a brief but comprehensive historical

introduction. The General Part treats in a very fundamental manner

the physical and chemical processes underlying all vital phenomena.

Especial attention is given to the characteristics of colloids, to the

general chemistry of enzymes, and to the nature of chemical action

in the same.

The Special Part opens with a chapter on the fats and lecithins.

Their distribution, metabolism, and storage in plants are made topics

of especial interest. In discussing the réle of lecithins, the author

shows reluctance in accepting any of the theories which assign to them

special réles.

The chemistry and occurrence of the sugars is the subject of a very

complete discussion occupying some forty pages. This discussion

opens the way for the author's extended treatment of carbohydrate

metabolism in the plant. He first treats of the storage of carbo-

hydrates and food value in fungi, bacteria (including alcoholic and

other fermentations), seeds, and subterranean storage organs. Then

he discusses with great fullness the carbon assimilation of the green

organs of plants. Naturally, his treatment is too extensive to be set

forth adequately in a review paragraph. Suffice it to say that the

author brings together the results of the best work on that subject

and discusses it fully from the standpoint of chemistry and biology.

The carbohydrates are treated from their origin in the plant to their

| Storage as reserve products in various storage organs.

Following the above subject in quite a logical manner comes the

study of the cell wall of the plant. First comes the unmodified cellu-

No. 476] NOTES AND LITERATURE 607

lose wall of simple plants or plant organs, then the hemicelluloses,

pectins, and pentosans, and finally the chemical and physical changes

which walls undergo. With these considerations the first volume

closes.

The second volume continues the treatment of chemosynthetic

activity. More than two hundred pages are devoted to the proteids.

Our knowledge of the general chemistry of vegetable proteids and of

proteolytic ferments is comprehensively written up and revised to the

end of the year 1904. The proteid metabolism of the bacteria, fungi,

ripe seeds, seedlings, etc., is given separate treatment. In successive

chapters the discussion takes up the proteid bodies, their cleavage by

ferments, absorption of the products by the plant, and formation of

reserve proteids.

One is gratified to find that the author sets forth at some length the

elucidating theory of proteid chemistry based upon the amino-acid

constitution. Since this new theory promises to clear up the “ mysteri-

ous" structure of the “awful proteid," it is proper that it receive a

prominent place in any comprehensive work on biochemistry.

he pyridin and chinolin bases are given very full treatment in

the discussion of alkaloids.

The phenomena of respiration, fermentation, and oxidizing enzymes

are made the principal topics of a long and interesting chapter on the

absorption of oxygen by plants. Here, as elsewhere, the author brings

out with force and clearness the chemical basis of the activities of living

matter. Naturally, the oxidation of carbohydrates and the distribu-

tion and constitution of the resulting vegetable acids receive extended

treatment at this place. The author is inclined to support the view

of Neubauer, that the vegetable acids have the function of neutralizing

the inorganic bases which are formed in ripening fruits. "The great

mass of literature on oxidizing enzymes is carefully brought together

and arranged in an orderly manner. The author points out that in

many studies of oxidases sufficient care has not been used to exclude

other enzymes.

e discussion of “omnicellular cyclic carbon compounds” i

largely devoted to quinone, phenols, and tannin. Czapek contends

that the concept of “tannin,” as used in botany, is altogether too loose,

this name being applied to any substance which turns black upon the

addition of iron chloride, but many substances like vanillin and mor-

phine react with iron like tannin. He probably sets forth the true

estimate of tannin when he shows that it does not perform any one but

a variety of functions in the plant.

[11

608 THE AMERICAN NATURALIST [Vor. XL.

One hundred and seventy pages are devoted to the róle of the mineral

elements in plants. It is probably safe to say that never before has.

this subject been so scientifically treated, nor has such a wide range

of analyses been collected into one work. In no other part of the work

does the author show greater breadth of mind and freedom from

provincial ideas than in dealing with this oft-debated subject. The

discussion treats in separate chapters the röle of the elements in bac-

teria and fungi, in seeds, in subterranean storage organs, in buds, in

the wood of trees, in the bark of trees, in leafy organs (including mosses

and ferns), in algee, in pollen grains, in fruits, and in roots. Not merely

are many tables of analyses given, but there is discussion upon the

probable value and function of each element to the plant. Much

discussion is given to the probable róle of elements like calcium and

magnesium, on which much work has been done. In the particular

case of these elements, the author brings together the results of a large

number of workers with great justice and precision. The work of

Loew is naturally given much prominence, yet he thinks that that

author has not in all cases taken a sufficiently broad view of the facts,

since too great importance is undoubtedly attached to the antagonism

of caleium and magnesium.

The last chapter of the book is devoted to a discussion of the re-

sponses of plants to chemical stimuli. Under different headings there

is brought together the work on the stimulation of protoplasmie

streaming; the stimulation of nuclear and cell division; the stimu-

lation of growth by toxic substances; the formative effect of chemical

stimuli upon vegetative and reproductive organs.

The book is indispensable to all workers in physiology, whether of

plants or animals, as well as in physiological and organic chemistry.

Lacouture's Liverworts of France. — This elaborate monograph

takes the form of a synoptical key which is arranged in three series

of tables; the first gives the characters of the tribes, the second of the

genera, and the third of the species. Seventy-five genera containing

two hundred and twenty-five species are described.

The characters upon which the classification rests are almost entirely

those of the vegetative structures, and they are minutely depicted.

'Lacouture, Ch. Hepatiques de la France. Tableaux synoptiques des

caractères saillants des tribus, des genres et des espèces. Paris, P. Klincksieck,

1905. 4 to 77 pp., 200 figures. |

No. 476] NOTES AND LITERATURE 609

The description of each species is accompanied by a distinct figure

showing the characteristics of the plant, especially those upon which

the classification is based.

Several new genera are created by raising subgenera to the rank of

genera. Jungermannia is divided to form the genera Sphenobolus,

Lophozia, and Aplozia; likewise, Riccia is divided to form three

genera, Ricciocarpus, Ricciella, and Euriccia; Cephalozia, to form

Eucephalozia and Cephaloziella.

The work is one which will prove to be very valuable, and it will be

particularly useful in classifying material which does not possess the

organs of fructification.

H. 5. R.

(No. 475 was issued July 11, 1906)

ENTOMOLOGY’

With Special Reference to Its BioLocıcaL and Economic Aspects.

By JUSTUS WATSON FOLSOM, Sc. D. (Harv.)

Instructor in Entomology at the University of Illinois.

With 5 Plates (1 Colored), and 300 other Illustrations. Octavo; 485 pages.

Cloth. $3.00 net. Just Ready

"A most careful and painstaking work, containing much nen praet only

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an expert has heretofore known where to find.' ge of

the Cera and Forage Crops Insect Investigations, Dept. p Krieg at

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“Mammalian amy: with Special — ae the (C " By ALVIN

Davison, A. M., .D. 110 Illustrations loth. $1.50 n

“The Foundations of Zoology." By T. W. Posen A. adt Ph. D

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‘Nervo | System of Vertebrates.” By Joun B. JouNsTON, Ph. D. 185 Ulus.

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I. Histogenesis of the Retina PROFESSOR A. W, WEYSSE AND W. S. BURGESS 611

II. Noteson Marine Copepoda of Rhode Island - . . . L.W. WILLIAMS 639

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DOUGLAS H. CAMPBELL, Pu.D., Stanford University

J. H. COMSTOCK, S.B., Cornell Ubi: Ithaca.

WILLIAM M. DAVIS, M. E., Harvard University, Cambridge

ALES HRDLICKA, M.D., U. S. National = useum, Washington

D. 8. JORDAN, LL.D. -Rionford Universit

CHARLES A. KOFOID, Pu.D., en of California, Berkeley

J. G. NEEDHAM, Px.D., Lake Forest University

ARNOLD E. ORTMANN, Pn.D., Carnegie Museum, Pittsburg

D. P. PENHALLOW, D.Sc., FRSO, McGill University, Montreal

: xe k

ngton

LEONHARD STEJNEGER, LL.D., Smithsonian Institution, Washington

W. TRELEASE, S.D., Missouri Botanical Garden, St. Louis

HENRY B. WARD, Ps. D., University of Nebraska, Lincoln

WILLIAM M. WHEELER, Pn.D., American Museum of Noal History,

New York

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THE

AMERICAN NATURALIST

Vor. XL September, 1906 No. 477

HISTOGENESIS OF THE RETINA!

ARTHUR W. WEYSSE AND WALDO S. BURGESS

INTRODUCTION

Tae histology of the vertebrate retina has been carefully inves-

tigated in several animals and the adult structure of that organ is

now fairly well understood, but the development of the retinal

elements has received very little attention. The literature on

the eye deals chiefly with the formation of the optic vesicles and

with the histology of the adult organ. The only writer who has

attempted to follow out the histogenesis of the retinal elements

appears to be Cameron (:05) in a series of papers on the develop-

ment of the retina in Amphibia, while Bernard (:00-:04) has

given some attention to the development of the rods and cones.

The investigations on which the present paper is based, were

made on the retina of the chick. This animal was selected for

study, first because it has never been investigated before, and

second because it affords so readily a complete series of stages

of development so that there need be no gaps for lack of material.

Since it has been necessary to compare the results obtained here

with those of Cameron, his technique has been followed closely,

but in addition certain modifications of it have been used, for

while in many cases by using his methods results precisely similar

to his have been obtained, yet by other methods results more in

accord with the known processes of cell and tissue development

in other organs of the body have been secured.

1 From the Biological Laboratory of Boston University, College of Lib-

eral Arts.

611

612 THE AMERICAN NATURALIST [Vor. XL

TECHNIQUE

In the course of this work several fixing reagents have been

tried with varying degrees of success. Of these, Kleinenberg’s

picrosulphuric mixture has proved entirely satisfactory in most

cases, but the best results have been obtained from the fluid

used by Cameron and known as the Bles fluid; it is made as

follows :—

70 % alcohol . : A 90 parts

Glacial acetic acid S

Commercial formalin . ; : : T

The embryos remained in this for one week and were then trans-

ferred to 70% alcohol.

When needed, the eyes were dissected out, cut in halves by a

vertical section through the optical axis, and placed in 90 % alco-

hol for three hours, followed by 95 % alcohol for from six to twelve

hours according to size. They were then cleared in cedar oil and

finally imbedded in paraffin, being passed through two paraffin

baths of one and three hours each, kept at a temperature of 53° C.

All sections were made with a Bausch and Lomb sliding micro-

tome and mounted in the usual way. All were stained on the

slide. |

In most cases two different staining methods were used in each

stage of development for the sake of comparison. These were a

33 % aqueous solution of Delafield’s hematoxylin followed by

an alcoholic solution of eosin, and an iron-alum preparation

described by Cameron.

This second method gave entire satisfaction in every respect

when modified by the subsequent use of eosin. The slide was

first placed in a 4 % aqueous solution of iron-alum, the violet-

tinted crystals, and allowed to remain ten minutes. This treat-

ment acts as a mordant of course. It was then thoroughly washed

in tap-water, dipped in a saturated aqueous solution of haema-

toxylin for ten minutes, and again washed in water. This left

the sections jet black. The slide was then placed once more in

the iron-alum solution and carefully watched until the sections

were of a light purple tint. They were then rinsed in water and

No. 477] HISTOGENESIS OF RETINA 613

examined under the microscope. If over-stained they were

bleached a little longer in the iron-alum, if not stained enough

the hematoxylin was repeated. The process has the advantage

that it admits of absolute control. The slide was next placed in

an alcoholic solution of eosin for about fifteen seconds and the

excess of stain washed out in alcohol. An oil-immersion lens is

absolutely essential for making out the details of retinal develop-

ment.

EARLIER STAGES OF RETINAL DEVELOPMENT

After the primary optic vesicle has invaginated to form the sec-

ondary optic vesicle or

optic cup, as shown in

Fig. 1, it is readily seen

that the invaginated por-

tion, the earliest stage in

the development of the

retina, and the uninvagi-

oe O p.

nated portion, which is [% | L \

continuous with it and e ?

is to become the pigment {f lees | 1

l . : SECHS

ayer, consist of nuclei Ej Be

n dee : DM Py

essentially similar in Bj Byes

structure, with more or Br 7 =

less granular protoplasm

aboutthem,—thetwolay- $e

Li . . . E RE

ers differing in thickness MNE

. Li oo

only. Karyokinesis at A he ©

this stage takes place at 02

the margins only of the f

optic cup, in both the

P Ps : 1G. 1.— Section through the entire optic cup o

retinal and the pigment 64 hours' embryo showing relative distribution re

avers the nuclei in the pigment we and theretina; the

y : mitotic figures indicate the only points at which

In the earliest stage in karyokinesis takes place s" this stage of develop-

ment. x 220. L, lens; p., pigment layer; r.

which the retina as such retina.

is to be identified, its

structure consists of nuclei suspended in cytoplasm without cell

614 THE AMERICAN NATURALIST [Vor. XL

walls, i. e., it is a syncytium whose outer and inner extremities

form the external and internal limiting membranes. This is

in accord with the conclusion of Bernard (:00). Early writers

described it as made up of discrete cells, while. Cameron goes

to the opposite extreme and maintains that it consists of nuclei

with absolutely no cytoplasm at all. Cytoplasm there certainly

is in the chick at this stage ifa cytoplasmic stain is used, but it

y is almost impossible to dem-

onstrate it with a nuclear

stain alone. It is difficult,

however, to determine just

what or how much cyto-

plasm is to be associated

with each nucleus since cell

walls are absent. The nu-

clei are evidently all alike

^ except for slight differences

N in shape, some being ellipti-

cal and some circular in out-

| line; this may be due to

their being cut in different

diameters. ‘The first meas-

ure 7.29” by 4.385, while

the second are 5.83” in

diameter. This is as large

as any retinal nuclei ever

Fig. 2.— Section through a portion of the retina become:

wed vi eros ts ee

ends. There is no cell division going on at this difference is apparent, there

point in the retina at this stage. x 810. ¢.7. is, however, an intrinsic dif-

m., external limiting membrane; 7. I. m., inner m4 í

limiting membrane, ference in these nuclei.

HS Those next the external

limiting membrane have the power of division, while the others

have not. These then may be called the row of germinal nuclei,

which vs this early stage are not dividing except at the junction of

the retina with the pigment layer, but division begins immediately

after the complete formation of the optic cup, so that karyokinetic

figures are found from margin to margin until the beginning of

differentiation of the retinal layers.

No. 477] ` HISTOGENESIS OF RETINA 615

The dividing nucleus is surrounded by a clear, fluid-filled

space several times as large as the other nuclei. Its outline,

though formed by the surrounding protoplasm, is so pronounced

as to simulate closely the appearance of an enveloping membrane.

This is well shown in Fig. 5.! In the one in the center the plane of

the section passes through the long axis of the spindle, while in

„b.v.

/ `

, in

fo e vec

ilm,

Fic. 3.— From a clin of the eye of an 84 hours’ a showing the numerous

blood skers in ge roh e close contact with ido iiu st which

here s of two laye nuclei embedded in mon cytoplasmic

mass Feen o pigm ib era = The wide isst x the external limit-

ing membrane from Hen ment layer is artificl Be £ Sil , blood vessel;

c., choroid; e. l. m., a limiting membrane; 7. x m., inner xri mem-

brane; p., pigment uic r., retina.

the others it cuts through or parallel with the equator. ‘Thus it is

seen that the plane of division is always perpendicular to the

external limiting membrane. No exceptions to this rule have

' All figures are from chick embryos and were drawn with the Abbé camera

lucida to the magnification indieated in each case; in some figures the details

were filled in with a higher magnifying power.

616 THE AMERICAN NATURALIST [Vor. XL -

been observed. After each division into two, one nucleus is left

behind to contribute one additional row to the thickness of the

retina while the other grows to its original size and divides again.

Thus the external limiting membrane is continually moving

outward the width of a nucleus with each successive generation

of germinal nuclei. The fate of the nuclei thus left behind will

be considered in connection with the various retinal layers.

Differentiation begins at the time the majority of germinal

Fic. 4.— Outline drawing of a section of the entire retina of a 7? days’ embryo.

The layer of rods and con

VII. The ga

: ; , ro IV, 32; from IV

7; from ar VI, 5; from VI to VII, 23; from VII to VIII, 56; from VIII

nuclei at the center of the retinal cup cease to divide, that is,

at the end of the period of most rapid growth. Commencing

thus at the center it gradually encroaches upon the territory of

No. 477] HISTOGENESIS OF RETINA 617

the undifferentiated margins. In this way every section contains

in its various parts all the preceding stages through which it has

passed. For instance a segment near the margin of a ten days’

retina would have attained the same degree of development as

a segment through the center of the retinal cup from a younger eye.

Hence in the discussion of development in this paper it is always

the most highly developed portion of the retina, the center, on

which all conclusions are based, and not the parts nearer the

margin, which invariably represent an earlier stage.

In the growth of the retina as a whole there are three well

defined periods: (1) the period of cell-multiplication, (2) the

period of readjustment, (3) the period of final differentiation.

The first, which extends from the second to the eighth day, is

characterized by a tremendous increase in the number of nuclei

and consequently in a rapid growth in the size and thickness of

the whole retina, which at the end of this stage has attained its

maximum width of 195. During the succeeding period of read-

justment, from the eighth to the tenth day, there is still a rapid

growth at the margins, but at the center of the retinal cup the num-

ber of nuclei is henceforth practically fixed, and the principal

change is that of redistribution or readjustment into layers. Inci-

dental to this there is a sudden decrease in width to 150 x, undoubt-

edly due to a stretching out of the surface area. The stage of

differentiation, extending from this time to the end of incubation,

is marked by the growth of cytoplasmic processes and by a grad-

ual increase to 180 in the thickness of the retina.

THE GANGLION-CELL LAYER

The ganglion-cell layer is the first to appear with the beginning

of the period of readjustment, as shown in Fig. 6. It consists at

first of three rows of nuclei which are marked off from the others

by the commencement of the inner reticular layer. As the surface

area of the retina increases, these nuclei, whose number of course

remains the same,! gradually fall into line, beginning at the center

! In a 7} days’ embryo a single dividing nucleus was found in this layer,

the only exception in the entire series studied.

618 THE AMERICAN NATURALIST [Vor. XL

of the retinal cup and thence radiating outwards on every side

toward the margins, until at the end of this period the layer comes

to be composed of a single phalanx of nuclei (Fig. 7). ‘This re-

adjustment takes place in the direction of the internal limiting

membrane as is shown by the fact that there is no corresponding

increase in the width of the nerve-fiber layer. Thus in its develop-

ment the ganglion-cell layer actually decreases in width from 28.6 x:

to 10.41.

Part of the nuclei of this layer are the same nuclei that were

seen in the early retina imme-

- diately after the formation of the

' optic cup (Fig. 1), and the re-

mainder are the first nuclei to be

formed by the division of the

germinal nuclei. All are of the

same size as those found in the

early undifferentiated condition;

: that is to say, after division each

angles to the external limiting membrane, grOWS to the size of the parent

mers external limiting mem-

brane; g. n., germinal nuclear layer. nucleus, a fact also true of the

amacrines or horizontal nuclei. At

the advent of the third stageof growth, with its attendant increase

in the amount of cytoplasm, these cells become multipolar and

gradually approach nearer and nearer the condition of the adult

retina.

THE [NNER NUCLEAR LAYER

The inner nuclear layer, which is by far the largest and most

conspicuous of all, has its beginning in the fourteen successive

generations of nuclei immediately following the production of

those which are eventually to become the ganglion cells. Fig. 12

shows this layer in the process of formation and Fig. 13 gives the

appearance three fourths of a day later. It does not become a

complete layer by itself until the beginning of the period of read-

justment when the outer reticular layer appears and separates it

from the future external nuclear layer; but long before this,

differentiation has already taken place.

No. 477]

HISTOGENESIS OF RETINA

619

In this layer the nuclei of the first generation become the inner

horizontal cells while the nuclei of the last generation become the

outer horizontal cells.

In both cases, as mentioned before, these

nuclei after division grow to the size of their immediate ancestors,

the early germinal nuclei.

uni

MD: "T , :

Sem SRD - N. : 4» D

: n T

ganglion-cell layer here

s of acer and the inner

reticular layer has a begun to form uclei

still dividing in the je minal Jay er, and

the' pigment layer is connected w the ex-

ternal limiting mem — ane by ee ae

strands , blo a ressel; e. l. m.,

external limiting membr ran 9:6, a...

cell layer; i. l. m., inner limiting. gen

i. r., inner reticular re ial api

of Müller; n. f., nervodiber layer; n aus

layer.

This, however, is not true of the inter-

mediate generations. Here

each successive phalanx

fails to attain quite the size

of the one preceding, so that

when the process is complete

we get the effect of a grada-

tion of nuclei apparent in

Fig. 15, where they range in

size from 5.83 u to 4.38 » in

diameter.

During the first two peri-

ods of growth the nuclei of

this layer, which measure

7.29 « by 2.92 p on an aver-

age, are all extremely ellip-

tical in outline, with the long

axis at right angles to the

limiting membranes. When

examined with a low mag-

nifying power they appear

sharply pointed at the ends,

and Bernard (:04) has fig-

ured them thus in his Plate

29, Fig. 25. But when

studied with the oil im-

mersion these nuclei are

seen to be elliptical and

bounded by a very distinct

membrane which is rounded

at the ends. They present

very much the appearance

of having been pulled outward toward the layer of germinal nuclei,

for the cytoplasm about them streams from each pole in the direction

620 THE AMERICAN NATURALIST [Vor. XL

of the limiting membranes. Some of these nuclei, especially those

near the middle of the layer, eventually become supporting cells or

fibers of Müller. This is well shown in Fig. 12. Up to the end

of the period of readjustment the chromatic substance of all retinal

nuclei is scattered about in the nucleus as several granules; later,

there is a single large, clearly defined chromatic mass. ‘This con-

dition appears to be true of other embryonic tissues as will be

seen by the figure, but it is especially evident in these elliptical

nuclei of the inner nuclear layer.

ee)

precy’

P pia ^ : j

6 s 4 e 1 X

[ ge.

> 1 mE os % zn eee ee ü do d e f dd

% (SE p^

- ta en

k & U"NiÁ

ww P. : "RS

F3 m T te

ilm,

Fic. 7.— Portion of the retina of a 10 days’ embryo. The ganglion-cell layer now

consists of two layers of nuclei. The inner reticular layer is well differentiated

horizontal cells. x 810. g., ganglion cell; g.c

zontal cells or amacrines; i. l. m., inner l

cular layer; n. f., nerve-fiber layer.

. ganglion-cell layer; h. c., hori-

To account for the enormous increase in the number of these

nuclei in so short a period two explanations have been advanced:

the theory of migration and the theory of direct division; neither

of these appears to us probable. The first is advanced by Bernard

(:00-:04). He states that in order to account for this rapid increase

in numbers “we have to assume a stream of nuclei from the un-

differentiated edges of the retina towards the base of the cup."

In another place in the same paper he asks the question: * Where

does the middle nuclear layer get its supply of nuclei to furnish

No. 477] HISTOGENESIS OF RETINA 621

the outer nuclear layer?” Our work on the chick demonstrates

clearly that the outer nuclear layer is not derived from the inner

nuclear layer in any sense of the word. Each layer is first laid

down by successive generations of nuclei from within outward

as Fig. 12 shows. As before stated this process is followed by a

later readjustment in each layer, but not by migration from one

layer to another. As for Cameron’s theory of direct. division

there is absolutely no evidence that such a process takes place in

the chick. Even at the center of the retinal cup mitotie division

does not wholly cease until nearly all the röds and cones have

reached an advanced stage of development.

From the time the outer reticular layer begins to appear at the

end of the first period of growth no more nuclei are added to the

inner nuclear layer. It has then attained its maximum thickness of

Pto pha,

Fic. 8.— An 88 hours’ embryo, in which Sie granules appear in the outer por-

tion of the pigment-layer cells; the nuclei of this layer are closely packed

together. x 810. b. v., blood vessel; p., pigment layer; p. g., pigment

granules.

111.85. The nuclei are all crowded very closely together, this

being especially true of the half of the layer nearer the external

limiting membrane. Then begins the period of readjustment,

during which the layer diminishes in thickness to 65 y. With the

stretching out in area of the whole retina and its consequent

restoration of equilibrium or equalization of tension, if we may so

express it, the nuclei become more loosely arranged and gradually

assume the circular outline, Figs. 13 and 15. The number of

phalanges, or rows of nuclei, which was at first fourteen, has now

decreased to eight, for there has been a gradual closing up of the

ranks in the direction of the external limiting membrane, made

evident by the corresponding increase in the width of the inner

reticular layer. oo

In the final stage of differentiation there is little change in this

622 THE AMERICAN NATURALIST [Vor. XL

layer except for a slight decrease in thickness from 65 u to 44.2 u.

The nuclei stain more deeply with the iron-alum hematoxylin,

and all are spherical except those of the supporting cells or fibers

of Miiller, while the nuclei of the horizontal cells are readily dis-

tinguished by their clearer texture. The cytoplasm of the layer

remains the same in amount and appearance as at the beginning.

THE RETICULAR LAYERS

The reticular layers are purely eytoplasmie in both origin and

structure, there being no evidence to the effect that nuclei have

anything to do with their formation. Each retinal nucleus, ex-

cept in mitosis, is always enveloped in an intact nuclear mem-

brane, and there are never appearances that might suggest the

. extrusion of nuclear substance or in the strict sense of the word

the protrusion of processes of any kind. To be sure, the cyto-

Fic. 9.— A 7 days’ embryo; the nuclei of the pigment layer are more widely sepa-

rated from each other; the pigment granules are more numerous and still en-

tirely on the outer side of these nuclei. x 810. b.v., blood vessel; p., pig-

ment layer; p. g., pigment granules.

plasmic processes of the bordering nuclei eventually extend into

these layers to varying depths, but there is no ground for the

assumption that such cytoplasm is of nuclear origin as Cameron

believes is the case in the frog.

The inner reticular layer, which is the first of these to form,

begins to appear at about the middle of the period of cell multi-

plication. It starts as a narrow protoplasmic rift between the

third phalanx of the early ganglion-cell layer and the first gener-

ation of nuclei in the future inner nuclear layer (Fig. 6). This

rift gradually widens, a little in the direction of the ganglion-cell

layer, but chiefly toward the inner nuclear layer as these two

layers develop. Viewed as a whole the layer has in section a

crescent-shaped outline, and as it develops the pointed edges of

No. 477] HISTOGENESIS OF RETINA 623

the crescent encroach more and more upon the undifferentiated

margins, as seen in Fig. 4.

The rate of development of this layer is fairly uniform from

the time of its first appearance to the end of incubation. At

the commencement of the period of readjustment it has attained

a width of 13 x, which has increased to 18.2 at its close. As

will be remembered, it is during this time that the ganglion-cell

nuclei fall into line, hence some of these stragglers are still to be

seen lingering behind in this layer (Fig. 7). These are the nu-

clei which Löwe (’78) and Falchi (’87) found it so difficult to

account for. From the beginning of the stage of differentiation

between the nuclei but do not yet occupy the cytoplasm between the external

limiting membrane and these nuclei. x 810. b. c., blood cell; b. v., blood

vessel; p., pigment layer.

onwards there is a constant increase in width up to 44.2 » which

is the final thickness of the inner nuclear layer.

Up to the stage of completed development the structure of this

layer is practically homogeneous throughout, but as differentia-

tion proceeds, vacuoles appear next the ganglion-cell layer so

that the appearance is like that in Fig. 15. Later the processes

from the ganglion cells and the cytoplasmic strands from nuclei

of the inner nuclear layer can be traced to varying depths, while

the fibers of Miiller extend perpendicularly across the layer from

the internal limiting membrane to the membrane of Henle.

The outer reticular layer begins to develop four or five days

later than the inner and toward the close of the period of cell

multiplication. Viewed as a whole it presents in section the same

crescentic appearance, but the horns of the crescent extend into

624 THE AMERICAN NATURALIST [Vor. XL

the undifferentiated region only half as far as those of the inner

reticular layer (Fig. 4). Its width never increases but remains

at 5.2, though the boundaries are not so clearly defined at first

and some straggling nuclei of the inner nuclear layer are still to be

Fig. 11.— A 164 days’ embryo showing the cytoplasm of the pigment sind com-

pletely ghe with pigment granules. 81 xm,

external limiting membrane; H. m., membrane of Henle; p., edil layer.

„ blood vesse

found in it up to the beginning of the stage of differentiation.

At this stage the membrane of Henle is formed by the flattening

of the inner ends of the rod and cone cells against the cytoplasm

of the horizontal cells and against the ends of the fibers of Müller

and of the processes from the inner nuclear layer (Fig. 13).

THe PIGMENT LAYER

The retina and the pigment layer, having as they do a common

origin, develop in physical contact from margin to margin, and

perhaps have an even more intimate connection, for the pigment

layer probably plays an important réle in the transfer of nutri-

tive fluids to the multiplying nuclei and growing processes of the

retina.

The pigment layer consists at first of two rows of closely packed

nuclei, each 5.83 in diameter and surrounded by protoplasm

which completely fills all the remaining space between the bound-

ing membranes. The appearance is much like that suggested

No. 477] HISTOGENESIS OF RETINA 625

by Fig. 3. It is a significant fact that even at this early stage

there are always numerous large blood vessels in the choroid

tissue just outside the pigment layer.

It will be noticed in Fig. 1 that growth of the pigment layer is

LEZA —

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The three layers of

identified, as

figures, the plane of division in each case being at right angles to ic nequ,

limiting membrane; these nuclei are all imbedded in granular cytop asm.

Xx 810. 'c, choroid: g. ¢.. B nglion-cell layer; g. n. 8 ;

i. l. m., inner limiting membrane; m. f., radial fibers of Müller; p., pigment

layer.

at the margins and that even as early as two and two thirds days

the surface area at the center of the cup has stretched out to such

626 THE AMERICAN NATURALIST [Vor. XL

an extent that the nuclei here have fallen into line so that the

layer consists of a single row of nuclei. The condition at the

margin of the optic cup remains the same as long as the eye con-

tinues to increase in size. Hence the row of actively dividing

nuclei is always relatively short compared with that of the retina

of which it is a direct continuation. After division the resulting

ee Kia

Ae SS RATS, rr,

' :

h i 1

SAL AL

Pd c [SR SEEN

Sansa

— The retina of a 10} days’ Sanges NE u p Arne of the

->rt

Fie. 1

aa reticular layer. In the er r layer can be distinguished the

al cells, bes Pilar die he nuclei P jii Cnt of Müller and

orizo is. Th

Bi ' and the cones as narrow

cytoplasmic processe 810. er s utt cell; c. n., cone elek: l ,

external limiting mimi i i

H mbr » nner hori-

zontal cells; o. h. c., outer u Tore ro., rods; r.n., “tod nuclei.

nuclei invariably grow to the size of the original nucleus, so there

is never any apparent diminution in their size.

Pigment commences to form as early as three and two thirds

days. Contrary to the statement which Cameron makes for the

No. 477] HISTOGENESIS OF RETINA 627

frog, the granules begin to appear in the chick on the side of the

layer away from the retina and in the protoplasm between the

nuclei, which shows them to be of cytoplasmic origin (Figs. 8 and

12). Cameron says that in the frog they appear first on the side

adjoining the retina. As development proceeds and the nuclei

become farther apart these granules gradually fill all the cyto-

plasm of the pigment layer on the side farthest from the retina

(Fig. 9). It will also be noticed that at the same time vacuoles

ERO ee 4

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b w s ; MES , ` h ‘

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S v^

V heal aeda, +

iT =

^. er,

a ER En X PARA

Y b iiia er Mr

A 1 eq T4

x BR 4

DN Lr. ty by A

d.C. j

m "

n.f.

Fic. 14.— Inner portion of the retina of a E days' wie The cells of th

apo Maui layer now lie practically in a single plane. The inner reticular

layer shows the large meshwork po its inner gap pee qe finer structure o

i x 8IO. J.e o ll layer; i. À. inner horizontal

cells; i. r., inner ‘reticular layer; n. TE pentes layer

begin to appear in the undifferentiated cytoplasm invariably

present between the pigment layer and the external limiting mem-

brane of the retina (Figs. 6 and 10). This cytoplasm is very

minute in amount at an early stage of development and later

increases greatly, taking the form of strands which are the begin-

nings of the future rods and cones and of the cytoplasmic streamers

which finally develop from the pigment layer and extend inward

628 THE AMERICAN NATURALIST [Vor. XL

between them. Meanwhile the eytoplasm about the nuclei be-

comes differentiated to such an extent that by sixteen and one

third days the layer is seen to be composed of clearly defined cells

each completely filled with pigment granules (Fig. 11). Later

all finer structure is entirely obliterated by the pigment, but no

granules are ever found normally outside their enveloping cyto-

plasm. The significance of these facts in the development of

the retina is seen in connection with certain theories which Ber-

nard has elaborated. He believes that pigment is a nutritive

substance which is constantly being ingested and absorbed by

the growing retina. This theory had its origin in Miss Huie’s

article on Drosera, in which she has succeeded in establishing

the fact of an intracellular digestion. Bernard goes so far as

to describe streams of absorbed pigment stretching through the

inner nuclear layer and forming the fibers of Miiller. Cameron

has accepted this theory and applied it in his study on the amphi-

bian retina. The nuclei, he believes, put forth an unformed

ferment or enzyme under the action of which the pigment granules

are rendered available for the metabolism of the cell. In this

way the rod and cone vesicles grow by successive digestions.

Before the theory is accepted, however, it must be shown

that pigment is actually a food substance and not as generally

supposed a waste product. The theory must be harmonized,

too, with the fact that pigment granules are extremely resistant

to the action of all known ferments or digesting fluids as Cameron

himself states. A further objection to the theory lies in the fact

that in the chick these granules first form on the side of the pig-

ment layer away from the retina, so that the rods begin to develop

before there is any pigment in their vicinity. If they are able to

begin to grow without it, is it not at least possible that they might

continue to develop without it ? Further, pigment is never found

outside the protoplasm of the pigment cell; none ever appears in

the retina, or even in contact with the rods and cones during their

development. Besides, may not the mediation of a third sub-

stance and in such an unavailable form be entirely superfluous,

for cannot the rods and cones obtain nutritive material for their

growth direct from the numerous blood vessels just outside the

pigment layer?

No. 477] HISTOGENESIS OF RETINA

THE OUTER NUCLEAR LAYER

629

The outer nuclear layer, which forms during the period of read-

justment, consists of two rows of nuclei. The one first laid down

and adjoining the membrane of Henle is the layer of cone nuclei,

Q.h.c.

Gu.

p- =

BRUNNEN ESS PENS A A AAA S A PM

Fig. 15.— Retina of a 163 days’ embryo from = are limiting membrane to

bra e. e fibers o

Müller are eviden rg inner add outer horizontal cells

- pear in the inn laye maining nuclei in this layer belonging

o bipolar cells iade the fibers of Made x810. bi. = bipolar cell; g. c.,

ganglion: ves re : H m., membrane of Henle; i. h.c ner horizontal cells;

VK , inner limiting membrane; i. r., inner se! ee 0. h. c., outer

eher te

which are fewer in number and more scattered in position (Fig.

13). The other, which borders on the external limiting membrane,

630 THE AMERICAN NATURALIST [Vor. XL

represents the last product of the division of the germinal nuclei.

In fact, division among them does not wholly cease until the rods

of their immediate neighbors have attained a high degree of

development. Thus the rod nuclei are the youngest in the retina.

All measure 4.38 « in diameter, which is the regular size of the

germinal nuclei after the first half of the first period of growth.

They suffer no diminution in size with the development of the rods

and cones, and least of all do they receive any accessions to

their number by a migration of nuclei from the inner nuclear

layer.

Long es division has ceased in the row of rod nuclei, in

elm, fact as soon as the outer nuclear

layer begins to appear at the cen-

ter of the retinal cup, the rudi-

ments of the future rods and

cones can be made out in the

shape of cytoplasmic threads or

"Hi dia do, AN - strands between the pigment layer

Fig. 16.— The davies of A rods 2. 1.

and The and the external limiting mem-

is idioti granular; ee brane. The rods and cones are

be. x 1500. c. n., cone nuclei: e.l. clearly of cytoplasmic origin.

a "ada" This cytoplasm slowly increases

in amount so that at the begin-

ning of the stage of differentiation the appearance is like that

shown in Fig. 13. It will be noticed that a fragment of the orig-

inal protoplasmic thread still tips the ends of some of the rod

rudiments, while the base of the rod appears drawn out into a

finely attenuated stalk whose inner extremity flattens against the

membrane of Henle. The base of the cone is shorter and much

broader (Fig. 16). As development proceeds, little or no change

takes place in the outer nuclear layer strictly so called except that

the nuclei toward the close of the period of differentiation stain

more deeply with the iron-alum hematoxylin. "This is true of all

retinal nuclei.

The cytoplasm of the rods, which at first is evenly granular and

homogeneous throughout, gradually increases in amount and as-

sumes more and more the conical appearance presented in Fig.

17. About the middle of the period of differentiation, a clear

No. 477] HISTOGENESIS OF RETINA 631

unstaining vesicle appears at the tip or outer segment and persists

in the same size and shape during the remainder of the develop-

ment of the rod. ‘There is no evidence that it is of nuclear origin

in the chick, although Cameron describes it as such in the frog.

The cytoplasm between this vesicle and the rod nucleus gradually

elongates as development proceeds but without any appreciable

increase in amount since at the same time the diameter diminishes,

and eventually a conical cap of protoplasm develops on the distal

end so that the unstaining vesicle appears like a fluid-filled vacu-

ole imbedded in the rod about a fourth the way from the finely

tapering point.

An interesting statement in this connection is made by Ber-

nard, and repeated in more elaborate form by Cameron, to the

effect that the nuclei

of the rods tend to

become protruded to

varying degrees þe-

yond the extemal lim-

iting . This

certainly does not seem

to be the case in the

chick, although at first

glance the appearance

is strikingly in accord

with such a statement.

In the base of many F's.

17.— The developing rods and cones in an 11 days’

embryo. The rods now show a clear outer pen

of the rods and Just and a granular inner zone. The cones

A the same as in the preceding figure. 1500. La.

outside the external cone anlage; c. n., cone nuclei; e. 7. m., ips limit-

limiting membrane ap- ing membrane; g. Z., ae zone of rod;

membrane of Henle; o. h. c., outer horizontal cella:

pears a structure that o. $., outer segment of rod; r. f., rod fiber; r. n., rod

might easily pass fora "cle

nucleus. The object

proved a puzzle for a time, but with more careful study its explana-

tion became clear. It was found that all the rods do not stand

exactly perpendicular to the external limiting membrane, but many

of them are bent over at various angles with it; and consequently

these structures that look so much like nuclei are the truncated

ends of other rods that once pointed toward the observer. By

632 THE AMERICAN NATURALIST [Vor. XL

focusing down on them the remainder of the stump can be

traced to its own nucleus. Hence the rod nucleus invariably

retains its early position wholly inside the external limiting

membrane. We have been unable to find such effects in the

chick as Cameron figures in the frog in his Pl. 51, Figs. 24 and

29, where the nucleus forms a distinct projection beyond the

limiting membrane.

VARIATIONS IN THE RELATIVE RATE OF DEVELOPMENT

In the development of the retina the time of appearance of the

different elements is not absolutely fixed. An eye at ten days

may have reached the same degree of development as another at

twelve, or again it may be no further advanced than some that are

two days younger. In the same retina it might be expected that the

state of development of one layer would bear some definite relation

to that of the others. But this is not the case. When the gan-

glion-cell layer has reached the stage shown in Fig. 6, the inner

nuclear layer may appear as shown in that figure, or it may be

more or less highly developed. Very frequently the inner nuclear

layer reaches a very advanced stage before any cytoplasmic

changes in the outer nuclear layer have begun to appear at all.

On the other hand the rods and cones may be developing rapidly

while the other layers are still in the earlier stages. The fact

has been mentioned before that when the majority of the rods

are in an advanced stage of development others are found beside

them whose nuclei have just ceased dividing and whose rudiments

have not begun to develop at all. Hence from the appearance

of a part it is impossible to predict the stage of development of

any other, for there appears to be no definite developmental ratio

that might serve as a criterion. The drawings in each case are

from the more typical representatives, and give the appearance

most frequent at the specified age.

SUMMARY AND CONCLUSIONS

1. The retina consists at first of a syncytium.

2. Most of these nuclei eventually go to form the inline

layer; those next the external limiting membrane become the ger-

minal nuclei.

No. 477] HISTOGENESIS OF RETINA 633

3. Only the row of germinal nuclei has the power of division.

4. ‘There are three well defined periods of growth: (a) the

period of cell multiplication, second to eighth day; (b) the period

of readjustment, eighth to tenth day; (c) the period of final differ-

entiation, tenth day to end of incubation.

5. Up to the end of the first period the retina grows from

within outward by the deposition of an additional row of nuclei

with each successive generation.

6. After this, karyokinetic figures are found only at the mar-

gins.

7. Differentiation begins at the center of the retinal cup and

gradually spreads in every direction toward the growing margins.

Between the center of the optic cup and the growing margin

of any given retina are represented all the different stages through

which it has passed; the nearer the margin, the younger the stage.

9. The ganglion-cell layer consists at first of three rows of

nuclei.

10. These fall into line in the direction of the internal limiting

membrane so as eventually to form but one layer.

11. In the inner nuclear layer differentiation into horizontal

cells, fibers of Müller, and bipolar cells takes place pari passu

with the formation of these nuclei.

12. This layer consists at first of about fourteen generations

of nuclei.

13. With the exception of the horizontal cells each successive

generation fails to attain quite the size of the one preceding.

14. As development proceeds the number of rows of nuclei

decreases from fourteen to eight by a closing up of the ranks in

the direction of the external limiting membrane.

15. Up to the end of the period of readjustment the nuclei of

this layer are elliptical in outline with the long axis at right angles

to the external limiting membrane.

16. Later these nuclei become circular in outline.

17. 'The reticular layers are cytoplasmic in both origin and

structure.

18. The pigment layer is a direct continuation of the retina.

19. Like the retina its early structure is also a syncytium.

20. The nuclei at first are in two rows which early become

arranged as one with the stretching out of the surface area.

634 THE AMERICAN NATURALIST [Von XL

21. Active growth is restricted to the margins of the pigment

layers and continues as long as the eye increases in size.

22. Nuclei of this layer are always of the same size as those

found in the early undifferentiated condition.

23. Pigment granules first form on the side of the layer away

from the retina and in the protoplasm between the nuclei.

24. ‘These granules are never normally found outside the cyto-

plasm of the pigment cell.

25. There is no evidence that pigment is a food substance.

26. The numerous large blood vessels always present in the

choroid coat next the pigment layer may furnish the nutritive

material for the development of the retina.

27. The outer nuclear layer represents the last two genera-

tions from the division of the germinal nuclei.

28. The rod nuclei are the youngest in the retina.

29. They are more numerous than the cone nuclei, and divi-

sion among them does not wholly cease until the rods of their

immediate neighbors have attained a high degree of development.

The rods and cones have theirforigin in undifferentiated

cytoplasm.

31. There is no evidence that any part of the rod or cone is of

nuclear origin.

32. The nuclei of the rods and cones retain their early posi-

tion wholly within the external limiting membrane and do not

tend to become protruded to varying degrees beyond it, as has

been recorded for other animals.

33. In the development of the retina there is no fixed time for

the appearance of the different elements.

BIOLOGICAL LABORATORY

STON UNIVERSITY

No. 477] HISTOGENESIS OF RETINA 635

BIBLIOGRAPHY

BABucH

'65. Veikinni Studien, nebst) einem Anhang zur

Entwicklungsgeschichte der Retina. War: naturw. Zeitschr.,

vol. z 2 127-143, pl. 4

BAMBEKE, C.

79. RER à l'histoire du développement de l'oeil humain..

Ann. Soc. Méd. Gand, pp. 1-22.

BARKAT, A.

'66. Beiträge zur Entwicklungsgeschichte des Auges der Batrachier.

Sitzb. Wien. Akad., vol. 54, pp. 70-74,

BERGMEISTER, O.

'80. Beiträge zur Entwicklungsgeschichte des Säugethierauges.

Mitth. embryol. Inst. Univ. Wien, vol. 1, pp. 63-84, pls. 6-7.

Patr, H. M.

Studies in the Retina. Quart. Journ. Micr. Sci., vol. 44,

pp. 443-469, pls. 30-31; vol. 46, pp. 25-76, pls. 3-5; vol. 47,

pp. 302-363, pls. 27-29.

Brass, ARNOLD.

'97. Atlas of Human Histology. London, 160 pp., 60 pls.

CAMERON, JOHN

:01. The More of the Processes of the Retinal Pigment Cells.

Proc. Scott. Micr. Soc., pp. 219-225, pl. 18.

:05. The Development of the Retina in Amphibia. Journ. Anat. and

Phys., vol. 39, pp. 135-153, 332-348, 471-488, pls. 21, 32,

40-42, 51-52

DoarEr, A. S.

’83. Die Retina der Ganoiden. Arch. f. mikr. Anat., vol. 22, pp-

419-472, pls. 17-19

92. Ueber die nervósen Elemente in der Retina des Menschen.

Arch. f. a Anat., vol. 38, pp. 317-344, pls. 19-22.

Everzxy, T. vo

"79. Bei $ zur Entwicklungsgeschichte des Auges. Arch. f. Augen-

heilk., Wiesbaden, vol. 8, pp. 305-356, pl. 3.

Farcnr, F.

'87a. Sull' istogenesi della retina e del nervo ottico. Ann. Ottalm.

Pavia, vol. 15, pp. 528-536.

’87b. Sur l'histogénése de la rétine et du nerf optique. Arch. Ital..

Biol., vol. 9, pp. 382-399, pl. 1.

636 THE AMERICAN NATURALIST [Vor. XL

Gunn, R. M.

'88. The Embryology of the Retina of Teleosteans. Ann. Mag. Nat.

Hist., ser. 6, vol. 2, pp. 263-269.

His, W.

'90. Histogenese und Zusammenhang der Nerven-elemente. Arch.

j. Anat. u. Phys., Suppl., pp. 95-118, 30 figs.

Humr, Li.

’96. Changes in the Cell Organs of Drosera rotundijolia produced

by feeding with Egg-albumen. Quart. Journ. Micr. Sci., vol.

39, pp. 387-426, pls. 23-24. ‘

'99. Further Studies in Drosera. Quart. Journ. Micr. Sci., vol. 42,

pp. 203-223, pl. 22.

KrssrER, L.

"TR: Untersachuhen über die Entwieklung des Auges, angestellt

am Hühnchen und Triton. Dorpat.

’77. Zur Entwicklung des Auges der Wirbelthiere. Leipzig, 112 pp.,

6 pls.

KÖLLIKER, A.

'83. Zur Entwicklung der Auges und Geruchsorganes menschlicher

Embryonen. Verh. phys.-med. Ges. Würzburg, n. s., vol.

17, pp. 229-257, pls. 10-13. `

LIEBERKÜHN, N.

Beiträge zur Anatomie des embryonalen Cas Arch. f. Anat.

u. Phys., anat. abth., pp. 1-29, pls. 1-2

Löwe, L.

"I8. Die Histogenese der Retina nebst vergleichenden Bemerkungen

über die Histogenese des Centralnervensystems. Arch. f.

mikr. Anat., vol. 15, pp. 596-630, pl. 37.

Manz.

’76. Entwicklungsgeschichte des menschlichen Auges. Handb. ges.

Augenheilk., Leipzig, vol. 2, pt. 2, pp. 1-57.

Martin, P.

'91. Zur Entwickelung der Netzhaut € der Katze. Zeitschr. f.

vergleich. Augenheilk., vol. 7, pp. 25-41.

Ramon Y CAJAL,

93. La ise des vertébrés. La Cellule, pp. 121-260, 7 pls.

REAL v BEYRO,

85. Contribution à l'étude de 1 'embryologie de l'oeil. Paris, 143 pp.,

4 pls. (Thèse

Rerzıus, G.

'81. pereg zur Kenntniss der inneren Schichten der Netzhaut des

Auges. Biol. Unters., vol. 1, pp. 89-104, pl. 1.

RIEKE, A,

’91. Ueber Formen und Entwickelung der Pigmentzellen der Chori-

oidea. Arch. f. Ophthalm., vol. 37, pt. 1, pp. 62-96.

No. 477] | HISTOGENESIS OF RETINA 637

SCHENK, G. L.

’67. Zur en des Ae o der Fische. Sitzb.

. Akad., vol. 55, pp. 480-492, pls.

SCHULTZE M.

'67. Bemerkungen über Bau und Entwickelung der Retina. Arch. f.

mikr. Anat., vol. 3, pp. 371-382. :

VASSAUX. |

'88. Recherches sur les premières phases du développement de l'oeil

chez le lapin. Arch. d'Ophthalm., vol. 8, pp. 523-547.

WÜRZBURG, A.

’75. Beitrag zur Bildungsgeschichte der Iris und Retina beim Kan-

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NOTES ON MARINE COPEPODA OF RHODE ISLAND

LEONARD WORCESTER WILLIAMS

WORK upon the non-parasitic Copepoda of America is very

fragmentary. In recent years the papers of Wheeler, of Gies-

brecht, and of Herdman, Thompson, and Scott record a rela-

tively small number of forms from what is apparently an extremely

rich fauna. Miss Rathbun’s check-list of the Crustacea of New

England records twelve free-swimming marine Copepoda. None

of these, however, is reported in the waters of Rhode Island.

This list records twenty-six free-swimming Copepoda, one

parasitic form, and a metanauplius of a parasitic copepod. Of

the free-swimming Copepoda eleven have been reported previously :

eight by Herdman, Thompson, and Scott from the Gulf of St.

Lawrence and six by Wheeler from the Wood’s Hole region. We

also describe three new species.

The material upon which this paper is based was obtained in

Narragansett Bay. Winter collections were made above Rocky

Point and summer collections near Wickford, and in Charlestown

Pond during the entire summer. The latter is situated in southern

Rhode Island and is a large shallow inlet (six miles long by one

broad) from the Atlantic. It is slightly brackish but the copepod

fauna is much the same as that of the bay.

I am indebted to Dr. A. D. Mead of Brown University for the

use of preserved material collected at Wickford by the Rhode

Island Commission of Inland Fisheries; to Professor C. B. Wilson

for kind assistance; and to Mr. Samuel Henshaw for the use of

books from the Museum of Comparative Zoölogy at Harvard.

Type specimens of the new species have been deposited in the

museum of the Boston Society of Natural History.

Calanus finmarchicus (Gunnerus)

1765. Monoculus finmarchicus Gunnerus.

1863. Cetochilus helgolandicus Claus.

639

640 THE AMERICAN NATURALIST [Vor. XL

1864. Calanus gti ae Boeck.

1878. Calanus finmarchicus Brady.

1892. Calanus Fe Giesbrecht.

1903. Calanus finmarchicus Sars.

This is a species widely distributed in the North Atlantic and

Arctic Oceans, having been taken by Nansen’s expedition above

85° north latitude. It has been twice reported from American

waters, by Thompson and Scott ('98) and by Wheeler (:00). It

appeared abundantly in tows taken in Narragansett Bay in Janu-

ary but was found at no other time. The specimens agree with

those taken by Wheeler in lacking the marked concavity of the

inner border of the basal joint of the fifth pair of legs of the female.

Pseudocalanus elongatus (Boeck)

1864. Clausia elongata Boeck.

1878. Pseudocalanus elongatus Brady.

1892. Pseudocalanus elongatus Giesbrecht.

1898. Pseudocalanus elongatus Thompson and Scott.

1903. Pseudocalanus elongatus Sars.

Narragansett Bay, January, February. This is a decidedly

northern form, its southern European limit being the northern

coast of France.

Centropages hamatus (Lilljeborg)

1853. Ichthyophorba hamata Lilljeborg.

1863. Ichthyophorba angustata Claus.

1864. Centropages hamatus Boeck.

1892. Centropages hamatus Giesbrecht

1898. Centropages hamatus Thompson and Scott.

1900. Centropages hamatus Wheeler.

1903. Centropages hamatus Sars.

Narragansett Bay, January, February. Wickford, summer.

Psrvupop1apromus Herrick

1884. Pseudodiaptomus C. L. Herrick.

1890. Schmackeria Poppe mo; J. Richard.

1894. Heterocalanus T. Scot

1894. Weismannella Dahl.

No. 477] RHODE ISLAND COPEPODA 641

Head separated from, or fused with the first thoracie segment;

fourth and fifth segments of the thorax fused (or not). Abdomen

of the female 4- or 3-jointed. Furca at least two and a half times

as long as broad, with six sete. First antenna 20- to 22-jointed.

Terminal section of the grasping antenna of the male usually 2-

jointed. The second antenna with a long outer ramus of two to

four joints. Outer ramus of mandible 3- or 4-jointed; inner

ramus inconspicuously 2-jointed, its second joint curved outward

strongly. The first joint of the basipodite of the second maxilla is

divided into two sections. Basipodite of the maxilliped short and

strong, inner ramus 4- or 5-jointed, some of its bristles branched.

The inner and outer rami of the first to fourth leg 3-jointed,

terminal joint of the outer ramus with two outer spines and a

terminal spine serrated externally. The inner ramus of the fifth

limb of the female rudimentary or absent, outer branch 2- or 3-

jointed. Inner ramus of the left fifth limb of male usually rudi-

mentary, rarely absent or transformed into a grasping organ;

outer ramus 2-jointed, occasionally reduced to a claw-shaped

process of the basipodite. Inner ramus of the right fifth limb

rudimentary or lacking; outer ramus 2- or 3-jointed with an end

claw. One or two egg sacs.

Pseudodiaptomus coronatus n. sp.

Figs. 1-7

The generic description must be modified slightly to admit

this species: the fourth and fifth thoracic segments are not fused

and the seventh and eighth segments of the first antenna are not

completely fused and if they are considered separate the first an-

tenna is 23-jointed. In other respects the species agrees with

the generic description. The last thoracic segment (Fig. 2) is

rounded posteriorly and is naked in the male and haired in the

female. The fourth thoracic segment is spined in the female

and naked in the male. Abdomen of male 5-jointed; of female

4-jointed. Almost all bristles of the feet and furca are jointed

some distance from their bases (Fig. 7).

Female.— First segment of abdomen much swollen with spines

642 THE AMERICAN NATURALIST [Vor. XL

and bristles arranged asymmetrically, and with a pair of spatulate

flaps (Figs. 4 and 5) extending over the genital aperture. The

bristles of the left side of the genital segment in both areas are

Fic. 3.— Fift

Fie

respectively much longer than those of the right side. A small

tuft of very long soft bristles near the posterior edge of the dorsal

No. 477] RHODE ISLAND COPEPODA 643

surface projects almost across the second segment. The left side

of the second segment of the abdomen has a small depression filled

with heavy bristles while the right side is convex and bears a few

spines (below the middle and so not shown in the drawing). The

‘ last segment has a crown of spines, on the posterior edge. The

furca is slightly asymmetrical and each ramus is five times as long

an " Popp:

Pseudodiaptomus coronatus

Fic. 5.— Genital segment of female, ventral surface. x 175.

Fio. 6.— Fifth limbs of female, posterior surface. 175.

Fic. 7.— Third swimming foot, female.

644 THE AMERICAN NATURALIST [Von XL

as broad and has long delicate bristles on the inner edge and

shorter and stronger bristles on the outer edge. The fifth limbs

are alike (Fig. 6) and 4-jointed. The terminal joint is prolonged at

the inner angle into a toothed lamella and has a spine at the outer

angle. The terminal claw is toothed along its inner (concave)

border and has a naked lamella on the inner side at base. One

large and one (right) small egg case.

Male.— Abdomen long and slender. First joint bristled along

the upper part of its posterior edge and with a semicircle of bristles

on the lower surface. The upper part of the hinder edge of

the second joint and the entire posterior edge of the third, fourth,

and fifth joints have a crown of triangular spikes. The furca

is three times as long as broad and lacks marginal bristles.

The right fifth limb (Fig. 3) has no inner ramus; outer ramus 2-

jointed with a terminal claw. First joint of basipodite has a

slender curved process coarsely toothed along its inner edge, the

second joint and the first joint of the outer ramus are toothed

inside. The second joint of the inner ramus has a bristled spine

and a curved terminal claw toothed on the inner edge and swollen

at base. The left fifth limb biramous. The first joint of the

basipodite has a cluster of three or four broad radiating spines.

The second joint has coarse teeth on its inner edge. The inner

ramus is a blade toothed along the distal half of its curved outer

edge. The outer ramus is 2-jointed; the first joint has an outer

terminal spine and the second joint ends irregularly in four spines.

'The right antenna (Fig. 1) has a terminal section of two joints

and has the third joint from the end toothed along its anterior edge.

Length of female 1.5 mm.; of male 1.2 mm.

Narragansett Bay and Charlestown Pond.

Temora longicornis (O. F. Müller)

1785. Cyclops longicornis Müller.

1850. Temora finmarchica Baird.

1865. Temora longicornis Boeck.

1878. Temora longicornis Brady.

1892. Temora longicornis Giesbrecht.

1898. Temora longicornis Pone and Seott.

1900. Temora longicornis Wheeler

1903. Temora longicornis Sars.

Narragansett Bay, January, February.

No. 477] RHODE ISLAND COPEPODA 645

EURYTEMORA Giesbrecht

1881. Eurytemora Giesbrecht.

1881. Temorella Claus.

Body moderately slender, rostrum with small, soft lappets.

Fifth thoracic segment free, often expanded laterally. Abdomen

slender, genital segment slightly protruding downward. Furca

elongated, symmetrical. Anterior antenna in female comparatively

short, scarcely longer than the cephalothorax, 24-jointed. Right

antenna of male geniculate, terminal portion of two (three ?)

joints. Posterior antenna with outer ramus longer than inner

and 7-jointed. Mouthparts similar to those of Temora except

that the posterior maxillipeds are shorter and stouter. Inner

ramus of the first leg 1-jointed, of the second to the fourth, 2-

jointed. Fifth legs of female 4-jointed, penultimate joint pro-

duced on the inside into a strong, pointed process; terminal joint

small. Fifth legs of male 4- or 5-jointed, about equal; terminal

joint of right leg claw-shaped, of left, spatulate or dilated.

Marine, brackish, and fresh water.

Eurytemora americana n. sp.

Figs. 8-11

Female.— The lateral angles of the last segment of the thorax

(Figs. 8 and 10) are drawn out into conspicuous triangular wings

which are distinct from the rounded posterior surfaces of the seg-

ment. The wing arises from the lower two thirds of the outer

side of the segment and its upper edge is slightly concave, and its

lower edge slightly convex. In lateral view it forms, with the

hinder edge of the segment, an S-shaped outline. ‘The abdomen

is 3-jointed; the genital segment is evenly rounded at the sides

and above but projects below; the genital opening is covered by a

broad, cordate fap. The upper surface of the anal segment and

furca is covered with short, strong spines. ‘The furcal arm is eight

times as long as broad, curved outward alittle, and slightly tapering.

The furcal setze, except the dorsal ones, are as long as the furca,

coarse, and swollen at the base. The dorsal seta is short and

646 THE AMERICAN NATURALIST [Vor. XL

jointed near the base. First antenna as long as the trunk and

strong. The fifth limb (Fig. 11) is similar to that of E. lacustris

but the penultimate joint is longer, and its inner process is more

slender and is finely bristled on both edges. The terminal joint

Eurytemora americana

Fig. 8.— Dorsal view of female, x 40

Fig. 9.— Fifth limbs of mal 3.

Fic. 10.— Left side of the fourth and fifth segments

Fic. 11.— Left fifth limb of female, anterior surface, x

e, anterior surface, 50.

of female,

bears two setze of nearly equal length, but the inner one is heavier

and is more distinctly bristled. The inner edges of the last and

next to the last joints bear long, slender bristles. Eggs light green.

Male.— Lateral angles of the last thoracic segment rounded.

No. 477] RHODE ISLAND COPEPODA 647

Abdomen slender, 5-jointed. Anal segment with few spines and

furca without spines on the upper surface. Furca six times as

long as broad, inner edge with long slender bristles. Furcal setze

as in the female, therefore longer than the furca. The left first

antenna is relatively longer than in the female, reaching to the

second segment of the abdomen. Right first antenna as in E.

herdmani, i. e., about as long as left antenna, very heavy, and with

the terminal portion composed of two long segments and a min-

ute terminal segment; seventeenth and eighteenth joints with a

comb-like ridge; nineteenth joint with a notch on the anterior

side at base and two toothed ridges beyond the notch. The

right fifth limb (Fig. 9) is 5-jointed, the last two not being fused

and the next to the last slightly swollen at base. Left fifth limb

5-jointed, the last joint separated from the fourth joint by an

oblique hinge and ending in three lobes, each with a spine upon

its apex.

The first to fourth limbs of both sexes are very similar to those

of E. velox.

Length of 2 , 1.8 mm.; cephalothorax, 1.07 mm.

Length of 3, 0.9 mm.; cephalothorax, 0.68 mm.

Narragansett Bay, January to April; Charlestown Pond, summer.

Males and females of this species were brought through the last

molt to sexual maturity. The males happened to molt earlier

than the females, and for some days each carried a spermatophore

by its stalk in the fifth limb, another spermatophore being almost

or quite fully formed within the body.

Eurytemora hirunoides (Nordquist)

1888. Temorella affinis var. hirunoides Nordquist

1898. Eurytemora affinis var. hirunoides Giesbrecht and Schmeil.

1903. Eurytemora hiruno des Sars.

Narragansett Bay, January; Charlestown Pond, J uly.

The specimens agree very closely with Sars’ description and

plates of the Norwegian form.

Eurytemora herdmani Thompson and Scott

1898. Eurytemora herdmani Thompson and Scott.

1898. Eurytemora herdmani Giesbrecht and Schmeil.

648 THE AMERICAN NATURALIST [Vor. XL

Narragansett Bay at Wickford. This species has been reported

previously from the Gulf of St. Lawrence only.

Acartia tonsa Dana

1849. Acartia tonsa Dana.

1892. Acartia tonsa Giesbrecht.

1900. Acartia tonsa Wheeler.

Charlestown Pond. Abundant throughout the summer. The

predominant copepod in the tow. The fifth limbs of the female

are symmetrical in all the specimens examined and not as in

Wheeler’s figure.

: Acartia clausii Giesbrecht

1892. Acartia clausii Giesbrecht.

1895. Acartia clausii Thompson.

1898. Acartia clausii Thompson and Scott.

1903. Acartia clausi Sars.

Narragansett Bay. Abundant in January and February.

This species has a very wide distribution, occurring in the Atlantic,

Mediterranean, the Black Sea, and the Gulf of Guinea (Scott,

'04). Thompson and Scott found it in the Gulf of St. Lawrence

but this is the first report of its occurrence in New England waters.

'TogrANUS Giesbrecht

1883. Corynura Brady.

1892. Corynura Giesbrecht.

1898. Tortanus Giesbrecht and Schmeil.

Head without lateral hooks; eye large, without cuticular lens;

no rostrum; a horseshoe-shaped fringed lamella in front of the

upper lip. Thorax symmetrical, last segment separate or fused

with the preceding. Abdomen of female often laterally compressed,

2- or 3-jointed. First antenna like that of Acartia, but the middle

section of the gripping antenna is thicker. , Two rami of the second

antenna of nearly equal length; terminal segment of outer ramus

rudimentary. Two rami of the mandible inserted at the end of

the elongated second joint of the basipodite. First maxilla consist-

ing of the first joint of the basipodite and the two much bristled

No. 477] RHODE ISLAND COPEPODA 649

inner border lobes. Proximal lobes of the second maxilla much

reduced. Maxillipeds 3-jointed. Inner ramus of first to fourth

swimming feet 2-jointed (or the first with 3 joints). Fifth limb

with one ramus in female, 2- or 3-jointed in the male, similar

to Acartia, but stronger.

Tortanus setacaudatus n. sp.

Figs. 12-15

Last thoracic segment free. First antenna long, 17-jointed,

reaching beyond the end of the furca by one or two joints. The

maxillipeds are extraordinarily large and are carried in a very '

characteristic manner, 7. e., horizontally and at right angles to the

sagittal axis, so that the long curved, bristled, and toothed sete

point forward. Abdomen and furca long.

Female.— Abdomen 3-jointed, slightly compressed laterally. The

left arm of the furca is sharply compressed laterally at its base;

otherwise the furca and abdomen are symmetrical. Genital seg-

ment enlarged, slightly rounded with a rounded prominence on

each side of the genital opening. Anal segment with an acute

strong dorsal spine. Each arm of the furca is fringed with soft

bristles along the distal half of its inner edge, and has the full

number of sete. Five of these are plumose and unjointed, and

one, the dorsal seta, projects upward from the plane of the others

and is naked and jointed near the base. The third seta from the

inside is longer than the majority and its projecting end bears

stiff, long bristles which are more scattered than the others, and

are attached at different angles. Feet of the fifth pair 2-jointed,

alike (Fig. 15). First joint oblong with a plumose bristle on the

outer edge near the end; terminal joint slightly narrower than the

first, with four short, broad spines, one near the middle of the

outer edge and three at the apex. |

Male.— Gripping antenna powerful; distal section of two joints,

middle section of six joints; of these, the second and fourth have

a seta at the distal end, and the fifth and sixth and the first joint

beyond the hinge have each a ridge which is finely toothed

and ends in a spine. Abdomen of five joints (Fig. 12). The

right side of the edge of the second joint is enlarged into a tubercle

650 THE AMERICAN NATURALIST [Vor. XL

which bears one or two minute spines. The anal segment is very

short and has a dorsal spine similar to that of the female (Fig. 13).

The right arm of the furca is slightly broader and longer than the

left and bears upon its outer edge near the middle a tuft of from

Tortanus setacaudatus

Fig. 12.— Dorsal surface of male. x 75.

Fic. 13.— Dorsal surface of male abdomen. x 172,

Fie. 14.— Fifth feet of male, anterior Surface, x 272.

Fic. 15.—Fifth feet of male, posterior surface, x 395.

No. 477] RHODE ISLAND COPEPODA 651

12 to 20 stiff, slender bristles which form a conspicuous brush.

The furcal setze and the hairs on the inner edge of the furca are

as in the female. Left fifth limb 3-jointed, more than twice the

length of the right (Fig. 14). Basal joint nearly as broad as long;

the second joint long, with one or more bristles on the inner and

outer edges; distal joint arcuate, pointed, nearly as long as the

other two, and with three recurved bristles on the outer and one

on the inner edge. Right fifth limb is 3-jointed, the last two

joints forming a heavy pincer; the second joint is spoon-shaped

and receives a curved spine borne on the lower (anterior) side

of the end of the swollen terminal joint.

Length of female 1.40 mm., of male 0.94 mm.

Abundant in Narragansett Bay and Charlestown Pond.

This is the second species of Tortanus to be described from the

eastern coast of North America. T. discaudatus Thompson and

Scott (98) from the Gulf of St. Lawrence is very similar to this:

. Species. T. bumpusii Wheeler (:00) was found in Vineyard

Sound and is apparently T. discaudatus.

Oithona plumifera Baird

1843. Oithona plumijera Baird.

1892. Oithona plumifera Giesbrecht.

1900. Oithona plumifera Wheeler.

Narragansett Bay, February.

Oithona similis Claus

1866. Oithona similis Claus.

1892. Oithona similis Giesbrecht.

1900. Oithona similis Wheeler.

Narragansett Bay at Wickford, June.

Longipedia coronata Claus

1863. Longipedia coronata Claus.

1880. Longipedia coronata Brady.

1898. Longipedia coronata Thompson and Scott.

1903. Longipedia coronata Sars.

Narragansett Bay and Charlestown Pond, summer. We have

found no American record for this species.

652 . THE AMERICAN NATURALIST [Vor. XL

Ectinosoma normani T. and A. Scott

1896. Ectinosoma normani T. and A. Scott.

1903. Ectinosoma normani Sars.

Charlestown Pond, summer. A species recorded from Norway,

‘Scotland, and Ceylon.

Ectinosoma curticorne Boeck

1872. Eectinosoma ‚curticorne Boeck.

1895. Ectinosoma curticorne Thompson.

1903. Ectinosoma curticorne Sars.

Charlestown Pond. One of the most common copepods in July

and August. It has been previously ponen from Norway, Scot-

land, and Spitzbergen.

Microsetella norvegica (Boeck)

1864. Setella norvegica Boeck.

1873. Ectinosoma atlanticum Brady and Robertson.

1890. Ectinosoma atlanticum Brady.

1892. Microsetella atlantica Giesbrecht.

1898. Ectinosoma atlanticum Thompson and Scott.

1903. Microsetella norvegica Sars.

Narragansett Bay, March. This species is cosmopolitan, with

:a wide distribution in the Atlantic Ocean and occurs in the Arc-

tic, the Pacific, the Mediterranean, the Red Sea, and the Indian

‘Ocean.

Tachidius littoralis Poppe

1881. Tachidius littoralis Poppe.

1895. Tachidius littoralis Thompson.

Narragansett Bay. Abundant in March and April.

Tachidius brevicornis (Miiller)

1776. Cyclops brevicornis Müller.

1853. Tachidius brevicornis Lilljeborg.

1880. Tachidius brevicornis Brady.

1882. Tachidius discipes Giesbrecht.

‘Charlestown Pond, summer.

No. 477] RHODE ISLAND COPEPODA 653

Parategastes sphericus (Claus)

1863. Amymone spherica Claus.

1866. Amymone spherica Claus.

1880. Amymone spherica Brady.

1903. Tegastes sphericus Norman.

1904. Parategastes sphericus Sars.

Charlestown Pond, abundant in July. The hand of the sec-

ond maxilliped in these specimens is somewhat heavier than in

the European species and resembles that of Tegastes grandi-

manus. Otherwise the agreement is complete.

Diosaccus tenuicornis (Claus)

1863. Dactylopus tenuicornis Claus.

1872. Diosaccus tenuicornis Boeck.

1873. Nitokra tenuicornis Brady and Robertson.

1880. Diosaccus tenuicornis Brady.

Charlestown Pond, July.

Dactylopusia vulgaris G. O. Sars.

1850. Canthocamptus stromii Baird.

1863. Dactylopus cinctus Claus.

1880. Dactylopus stromii Brady.

1903. Dactylopusia vulgaris Sars.

Charlestown Pond, July.

Thalestris serrulata Brady

1880. Thalestris serrulata Brady.

1895. Thalestris serrulata Thompso:

1898. Thalestris serrulata fish aad Scott.

One female of this somewhat rare species was taken by scraping

piles at high tide at Rocky Point in Narragansett Bay. Thomp-

son and Scott have reported it from the American coast.

Harpacticus uniremis Kró yer

1845. Harpacticus uniremis Króyer.

1903. Harpacticus uniremis Sars.

654 THE AMERICAN NATURALIST [Vor. XL

Narragansett Bay, abundant in February, March, and April;

Charlestown Pond, July. Females in egg were found in both

the summer and winter tows, though the largest number of speci-

mens in copula were taken in March and April. The species

was found in great abundance in shallow water and not, as Sars

reports of the Norwegian specimens, confined to depths of from

twenty to a hundred fathoms.

Harpacticus chelifer (Müller)

1776. Cyclops chelifer Müller.

1834. Harpacticus chelijer Milne-Edwards.

1880. Harpacticus chelifer Brady.

1903. Harpacticus chelifer Sars.

Charlestown Pond, July.

Idya furcata (Baird)

1837. Cyclops furcatus Baird.

1863. Tisbe furcata Claus.

1864. Idya furcata Boeck.

1880. Idya furcata Brady.

1903. Idya furcata Sars.

Narragansett Bay, spring. This is a very common Norwegian

copepod and is “ubiquitous in the British seas” to quote Dr.

Brady. It is also found in the Mediterranean, the Red Sea,

and in New Zealand.

Argulus laticauda Smith

1874. Argulus laticauda Smith.

1903. Argulus laticauda Wilson.

1904. Argulus laticauda Wilson.

Charlestown Pond on tautog (Tautoga onitis).

Metanauplius of Caligus or Lepeophtheirus

Figs. 16=23

Two specimens of this metanauplius were taken near the sur-

face, one on January 13 on the east side of the upper part of

No. 477] RHODE ISLAND COPEPODA 655

Narragansett Bay (Crescent Park), the other a week later on the

opposite side of the bay (Pawtuxet). They resemble in general the

metanauplius raised from the eggs of Caligus bonito by C. B. Wil-

Fic. 16.— Dorsal view. x 123.

Fig. 18.— Left arm of furca. x 345.

Fic, 19.— Right first maxilliped. x 345.

Fie. vei Right second maxilliped. x 345.

Fic. 21.— Right maxilla or mandible, x 345.

Fic. eg — Left first antenna, x 345.

Fic. 23.— Left second antenna. X 345.

656 THE AMERICAN NATURALIST [Von XL

son (Proc. U. S. Nat. Mus., vol. 28, figs. 40-45, 1905). Pro-

fessor Wilson says of my specimens it is “the first instance on

record where one has been obtained in its free habitat." The

capture proves his inference that the metanauplius is free-swim-

ming. However, even the genus cannot be positively identified

since Professor Wilson's metanauplius is the only one as yet recog-

nized. (The two specimens described by Brady (99) from Otago,

New Zealand, and named provisionally Centromma thomsoni, are

very like my specimens and must belong to the Caligidz rather

than to the Coryceide.)

Length 0.63 mm.; breadth 0.157 mm.

'The carapace is moderately slender and is marked near the

middle by a slight notch on each side (Fig. 16). In front of these

notches lie the eyes, the two pairs of antenns, the protrusive

toothed proboscis, the maxilla (?), and two maxillipeds. ‘There

seems to be a groove or depression in the dorsal surface of the

carapace which runs backward from the front almost to the eyes.

The ruby-red eyes are fused and lie just in front of the notches of

the carapace. The first antenna (Fig. 22) arises some distance

from the anterior end of the carapace and passes forward to its

tip, then turns backward and downward towards its origin, and

finally outward. The first portion seems to consist of two joints:

a basal joint which is not clearly marked off from the carapace

and which bears at its outer distal angle a strong spine, and a dis-

tal joint which is about twice the length of the first. The second

portion is formed of two joints: a long one which bears two bristles

and a short joint whose end is drawn out on the side next the cara-

pace (outer side) into a long bristle. The distal portion of the

antenna is a single joint which seems to be held almost at right:

angles to the sagittal axis of the metanauplius. Its end bears

ten or twelve (or more) bristles, most of which are long and all

non-plumose and flaccid. The second antenna (Fig. 23) is

biramous. ‘The basal joint is short and broad, and lies just inside

that of the first antenna. The inner ramus is slender and rela-

tively short, and ends in a tuft of four or more unjointed spines.

The outer ramus is 2-jointed. The proximal joint is moderately

swollen at the base but tapers distally. The distal joint is a hook.

swollen at the base.

No. 477] RHODE ISLAND COPEPODA 657

On each side of the mouth there is the structure represented in

Fig. 21 whose identity is not clear but which probably represents

the maxilla. It is a ridge which bears in front a 2-jointed appen-

dage and ends posteriorly in a strong spine. The basal joint of

the appendage is drawn out posteriorly into a curved spine, swollen

at base. It is possible that this represents the outer ramus and the

basal portion of the appendage. The distal joint is oval, outwardly

directed, and ends in two strong bristles. The first maxilliped

(Fig. 19) is 2-jointed, heavy and short. The distal joint terminates

in two claws, of which the outer is bristled and the inner finely

toothed or bristled. The second maxilliped (Fig. 20) is 3-jointed.

'The basal joint bears near the middle of its inner surface a strong,

backwardly directed spine. The second joint is about one half

as long as the first. The distal joint is a sickle-shaped hook with

a spine at base. The mouth is supplied with a protrusible pro-

boscis which is a truncated cone armed at the apex with a circle

of inwardly directed spines. "This suggests that the metanauplius

is ready to attach itself to a host.

At the posterior end, the carapace bears a pair of swimming

legs. The first of the free thoracic segments bears a pair of legs

and the second has on each side two spines. Two segments follow,

the first without appendages, and the second, the anal segment,

with the short furca. The two pairs of legs are very similar.

Each has a single basal joint and two 1-jointed rami. "There is a.

feathered bristle on the tip of the outer edge of each basal joint.

The outer ramus of the first pair of swimming feet has four spines,

one at the outer side and three at the end, and three long feathered

bristles. The inner ramus has a smooth outer edge which bears

an unjointed spine at the end. The inner edge has six (or seven)

long feathered bristles. The second pair of legs (Fig. 17) is

similar except that the outer ramus has three spines and four bristles

and the inner ramus is broader than in the first pair. Each anal

lamella (Fig. 18) (ramus of the furca) is short and irregular, and

bears five bristles. The outer furcal seta is plumose on the outer

side and the inner seta is plumose on both edges.

658 THE AMERICAN NATURALIST [Vor. XL

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"4. Report upon the RESTE Animals of Vineyard Sound.

Rept. = S. Fish Comm. jor 1871-72, 478 pp., 38 pls.

WHEELER, W.

vates of the Wood's Hole Region. Bull. U. S. Fish Comm.

for 1899, vol. 19, pp. 157-192, 30 text-figs.

Wirsow, C. B.

:03. American Parasitic Copepoda of the Family TES Proc.

U. S. Nat. Mus., vol. 25, pp. 635-742, pls. 8-

:04 Fish Parasites of the Genus Argulus from the wo s Hole Region.

Bull. U. S. Bureau of Fisheries, vol. 24, pp. 117-131.

:06. North American Parasitic Copepods. Proc. U. S. Nat. Mus.,

vol. 28, pp. 479-672, pls. 5-29.

Brown UNIVERSITY

LICHENS OF MOUNT MONADNOCK, NEW

HAMPSHIRE

. REGINALD HEBER HOWE, JUNIOR

Mr. Monapnock (3166 feet), the typical representative of the

monadnock type of worn-down mountain, is situated in the south-

eastern corner of Cheshire County, N. H., in the townships of

Jaffrey and Dublin. It rises from well watered, rolling meadow

and woodland country of the Transition zone, and though sur-

rounded by several prominent hills, Gap (1900 feet) for example,

it stands well isolated. The lower slopes of the mountain are

covered with upland pastures and woodlots, while between the

altitudes of 2000 and 3000 feet of the Sub-Canadian zone, its

sides are well wooded with both coniferous and deciduous growths.

Above 3000 feet the fauna and flora of its weathered, rounded,

and rocky summit of resistant ledges are characteristic of the

Canadian zone.

The lichens here listed were collected on April 5, 1906, about

the base of the mountain on the Troy side, and on Bigelow Hill

(1702 feet), and again on April 6, 1906, during one ascent to the

summit of Monadnock itself.

Examples of all specimens listed are in my herbarium. For

the verification of determinations of the genus Cladonia, and of

several other specimens I am indebted to the kindness of Profes-

sor Bruce Fink of Grinnell, Iowa. To Mr. Rollin M. Gallagher

I am also indebted for assistance in collecting.

calicaris fraxinea Fr.— One specimen collected on

a cherry tree, Bigelow Hill. Fertile.

2. Ramalina calicaris fastigiata Fr.— Common in the Transi-

tion zone. Found on cherry, elm, and on Bigelow Hill on a rock.

Fertile.

3. Ramalina calicaris canaliculata Fr.— One specimen collected

on an elm, Bigelow Hill. Fertile.

661

662 THE AMERICAN NATURALIST [Vor. XL

4. Ramalina calicaris farinacea Schaer.— One old wall had

several patches on individual rocks. ‘Transition zone. Sterile.

5. Cetraria islandica (L.) Ach.— Common in a reduced

state on the ledges near the summit. Sterile.

6. Cetraria ciliaris (Ach.).— Not uncommon on pines near the

base. Fertile.

7. Cetraria lacunosa Ach.— Common on pines on Bigelow

Hill and about the base of the mountain; rare in the Sub-Canadian

zone. Fertile.

S. Cetraria oakesiana Tuck.— Common in the Sub-Canadian

zone on dead wood, yellow birch, oaks, and in one instance on rock.

Sterile.

9. Cetraria juniperina pinastri Ach.— A few examples on a

fallen spruce at timber line. Sterile.

10. Evernia prunastri (L.) Ach.— Common in the Tran-

sition zone, rare in the Sub-Canadian. Found growing on old

roofs, stone wall, on Parmelia perlata on rock, and on deciduous

trees. Sterile. : |

11. Usnea barbata florida Fr.— Uncommon on oaks on

Bigelow Hill. Sterile.

12. Usnea barbata florida rubiginia Michx.— Bigelow Hill.

Uncommon on oaks. A small but fairly typical specimen was col-

lected on a rock, which proves that the coloring is not due to

tannin or some other vegetable coloring matter in the bark of

trees as has been suggested. Sterile.

13. Usnea barbata ceratina Schaer.— One untypical speci-

men collected on an oak on Bigelow Hill. Sterile.

14. Alectoria jubata chalybeiformis Ach.— A single specimen

was collected on Bigelow Hill on the ground, growing with

Cladonias.

15. "Theloschistes concolor effuse Tuck.— Two small specimens

on oak on Bigelow Hill.

16. Parmelia perlata (L.) Ach.— Common on rocks through-

out the Transition and Sub-Canadian zone.

stances.

17. Parmelia cetrata Ach.— Two examples on oak on Bige-

low Hill.

18. Parmelia crinita Ach.— One example growing on moss On -

apple tree. Bigelow Hill. Sterile.

Fertile in two in-

No. 477] NEW HAMPSHIRE LICHENS 663

19. Parmelia tiliacea (Hoffm.) Floerk.— Common through-

out Transition and Sub-Canadian zones. Collected on apple and

yellow birch. Fertile.

20. Parmelia borreri rudecta 'luck.— Common in Transi-

tion and Sub-Canadian zones. Collected on yellow birch. Sterile.

2]. Parmelia saxatalis (L.) Fr.— Not uncommon on rock.

Transition zone. Fertile.

22. Parmelia saxatalis sulcata Nyl.— Common in both Tran-

sition and Sub-Canadian zones, growing on trees and rock.

Sterile.

23. Parmelia physodes (L.) Ach.— Common throughout

both Transition and Sub-Canadian zones, but more common in

the latter. One example fertile. Collected on trees, and rarely on

rocks.

24. Parmelia olivacea (L.) Ach.— Common in Sub-Canadian

zone on yellow birch and oak. Fertile.

25. ? Parmelia olivacea sorediata (Ach.) Nyl.— One speci-

men collected on a white pine at the base of the mountain seems

referable to this form.

26. Parmelia caperata (L.) Ach.— Common in Transition

zone, more rarely met with in the Sub-Canadian. Collected both

on rocks and on trees. Sterile. When found growing vertically

on rocks this species has a deceptive shredded appearance.

27. Parmelia conspersa (Ehrh.) Ach.— Common throughout the

two lower zones growing on rocks, replaced by the following spe-

cles above timber line. Fertile.

28. Parmelia centrifuga (I..) Ach.— Not uncommon above tim-

ber line, confined mainly to the highest ledges. One example

fertile.

29. Physcia pulverulenta leucoleiptes T'uck.— Common in the

Transition zone on apple trees. Sterile.

30. Physcia stellaris (L.).— Common both on rocks and trees.

Fertile.

31. Physcia stellaris aipolia Nyl.— One example collected on

a rock. Bigelow Hill. Sterile.

32. Physcia tribacea (Ach.) Tuck.— One example collected on

rock on Bigelow Hill. Fertile.

33. Physcia obscura endochrysea Nyl.— Common on yellow birch

in the Sub-Canadian zone. Sterile.

664 THE AMERICAN NATURALIST [Vor. XL

34. Pyxine sorediata Fr.— Not uncommon on beech in Sub-

Canadian zone. Sterile.

35. Umbilicaria hyperborea Hoffm.— Found both on the top of

Bigelow Hill on boulders, and on the summit ledges of Monadnock.

36. Umbilicaria muhlenbergii ( Ach.) Tuck.— Growing on pasture

rock at the base of the mountain. Fertile.

37. Umbilicaria dillenii Tuck.— Common on ledges in the Sub-

Canadian zone.

38. Umbilicaria pennsylvanica Hoffm.— Several specimens were

collected on ledges at about 2500 feet elevation. Fertile.

Umbilicaria pustulata papulosa 'l'uck.— Common on pasture

rocks and on the mountain ledges nearly to the summit. Fertile.

40. Sticta amplissima (Scop.) Mass.— Common on yellow birch

on the mountain and also on rocks on Bigelow Hill. Fertile.

41. Sticta pulmonaria (L.) Ach.— Common in both Transition

and Sub-Canadian zones on oaks and yellow birch, and in a few

instances on rocks. Sterile.

42. Nephroma tomentosum (Hoffm.) Koerb.— One example on

rock in Sub-Canadian zone. Fertile.

43. Nephroma levigatum Ach.— One example on rock, Sub-

Canadian zone. Fertile.

44. (?) Peltigera canina (L.) Hoffm.— On ground over ledges,

not uncommon. Bigelow Hill. Sterile.

45. Pannaria lanuginosa (Ach.) Koerb.— Common on rocks in

the two lower zones. Sterile.

46. Ephebe solida Born.— One example on rock, Bigelow Hill.

Determined through the kindness of Dr. Herbert M. Richards of

Barnard College, N. Y.

47. Leptogium tremelloides (L. fil.) Fr.— One example on rock,

Sub-Canadian zone. Sterile.

48. Placodium vitellinum (Ehrh.) Noeg. & Hepp.— One ex-

ample on old barn, Transition zone. Fertile.

49. Lecanora rubina (Vill.) Ach.— Common on rock on Bigelow

Hill. Fertile.

90. Lecanora subfusca (L.) Ach.— One example on yellow birch.

Fertile.

9l. Lecanora pallescens (L.) Schaer.— One example on yellow

birch in Sub-Canadian zone. Fertile.

No. 477] NEW HAMPSHIRE LICHENS 665

53. Stereocaulon paschale (L.) Fr.— Common on rocks in Sub-

Canadian zone. Fertile.

54. Stereocaulon tomentosum (Fr.) Th. Fr.— One example on

rock in Sub-Canadian zone. Fertile.

55. (?) Cladonia cariosa (Ach.) Spreng.— One example on

ground, Sub-Canadian zone. “An unusual form to be studied

further. "— Fink.

56. Cladonia pyxidata (L.) Fr.— Common, Sub-Canadian zone.

57. Cladonia fimbriata nemoxyne (Ach.) Coem.— Two examples,

mossy ground and old stump, Sub-Canadian zone.

58. Cladonia fimbriata coniocrea (Floerk) Wain.— One example

on ground, Sub-Canadian zone.

59. Cladonia squamosa Hoffm.— One example on ground, Sub-

Canadian zone.

60. Cladonia furcata (Huds.) Fr.— Common on ground, Sub-

Canadian zone.

61. Cladonia furcata (racemosa Fl. or pinnata (Fl.) Wain.?) —

One example on ground, Sub-Canadian zone.

62. Cladonia rangiferina (L.) Hoffm.— Abundant on ground in

all three zones.

63. Cladonia rangiferina sylvatica L.— Common on ground,

particularly in the two lower zones.

adonia amaurocrea (Fl.) Schaer. (furcata ?).— Common

on ground between ledges in Canadian zone.

65. Cladonia uncialis (L.) Fr.— One example on ground, Can-

adian zone.

66. Cladonia boryi Tuck.— Common on ground in a reduced

condition in Canadian zone.

67. Cladonia (Cornucopoides) coccifera (L.) Willd.— Common

on ground in Sub-Canadian zone.

68. Cladonia coccifera pleurota (Fl.) Schaer.— One example

on ground, Sub-Canadian zone.

69. Cladonia bacillaris Nyl.— One example on fallen stump on

ground, Sub-Canadian zone.

70. Cladonia cristatella "l'uck.— Common in two lower zones.

71. Graphis scripta Ach.— One example on beech, Sub-Can-

adian zone.

NOTES AND LITERATURE

BOTANY

Notes. — A monograph of Primulacex, by Pax and Knuth, forms

Heft 22 of Engler’s Das Pflanzenreich.

An account of a large white elm, with figures, is given by Williams

in Forest Leaves for February

A case of trunk-grafting of the elm is illustrated in Sports Afield

for February.

An interesting series of Rumex illustrations, including hybrids, is

being published in vol. 24 of Reichenbach’s Icones Flore Germanice

et Helvetice.

The Camus monograph of the willows of Europe has recently been

completed by the issuance of a second part, with atlas, from the

Lechevalier House, of Paris.

Engler revises the pothoid Aracee in Heft 21 of Das Pflanzenreich.

The rediscovery of Cypripedium fairieanum is sketched by Barron

in The Garden Magazine for March.

A domestically interesting Aloe, from Angola, is described by Berger

in the Journal of Botany for February.

Foliage anatomy and its classificatory value in Festucacez are con-

sidered by Luerssen in Heft 63 of Bibliotheca Botanica.

A series of photographic illustrations of agriculturally interesting

grass glumes is given by Neubauer in Landwirtschajtliche Jahrbücher

for December 18.

Sorghum halepense, like S. vulgare, is said to yield hydrocyanic acid

sometimes under the influence of enzymes, by Crawford, in Bulletin

no. 90, part 4, of the Bureau of Plant Industry, U. S. Department of

Agriculture.

A popular note on evergreens, with some Conifer illustrations, is

published by Maynard in Suburban Life for February.

667

668 THE AMERICAN NATURALIST [Vor. XL

A reprint of the Lloyd edition of “Travels in the Interior of North

America,” by Maximilian, Prince of Wied (London, 1843) is being

issued as volumes 22 to 24 of Thwaites’ Early Western Travels: 1748-

1846 — with atlas. i

An account of the forest belts of western Kansas and Nebraska, by

Kellogg, forms Bulletin no. 66, Forest Service, of the U. S. Department

of Agriculture.

An account of the wild and cultivated Amaryllidaceæ of Argentina

is given by Holmberg in vol. 5 of the current series of Anales del Museo

Nacional de Buenos Aires.

An interesting account of the macroplankton, or free-floating arche-

goniates and spermatophytes of the pools of Paraguay is given by

Chodat in.the Bulletin de l’ Herbier Boissier of January 31.

An Enumeration of the Vascular Plants known [rom Surinam,

Together with their Distribution and Synonymy, by Pulle, has been

issued from the Brill press of Leiden.

A dichotomous key to French plants has been published by Léveillé

(Paris, Chas. Amat, 1906), in convenient pocket form.

A monograph of the Aconites of India, by Stapf, forms vol. 10,

part 2, of the Annals of the Royal Botanic Garden, Calcutta.

The utilization of seaweeds of the United States is considered by

Smith in vol. 24 of the Bulletin of the Bureau of Fisheries.

Mushrooms and their cultivation form the subject of a well illus-

trated article by McAdam in Country Life in America for February.

A paper on the Russulas of Madison and vicinity, by Denniston, .

has been separately printed from vol. 15 of the Transactions of the

Wisconsin Academy.

A note on the poisoning of cattle in Manitoba by Amanita muscaria

and a species of Boletus is published by Criddle in The Ottawa Nat-

uralist for February.

A brief account of the mechanism by which Salix, Cladrastis, Tilia,

and other woody genera discard their terminal buds in a characteristic

manner, is given by Tison in Comptes Rendus....de l'Académie des

Sciences of Paris for January 22.

Weevil-resisting characters in cotton, some of them connected with

the “kelep” ant, form the subject of Bulletin no. 88 of the Bureau

of Plant Industry, U. S. Department of Agrieulture, by Cook.

No. 477] NOTES AND LITERATURE 669

An account cf some phases of the ecology of plants of the extreme

north has recently been issued by Haglund, of Upsala

A list of wild medicinal plants of the United States, by Alice Henkel,

forms Bulletin no. 89 of the Bureau of Plant Industry, U. S. Depart-

ment of Agriculture.

The botanical treatment in the new National Standard Dispen-

satory (Lea Brothers & Co., 1905) is by Rusby.

An economic account of Mentha piperita and its varieties is given

by Alice Henkel in Bulletin no. 90, part 3, of the Bureau of Plant

Industry, U. S. Department of Agriculture.

An account of the Japanese lac derived from Rhus is given by

Stevens in The American Journal of Pharmacy for February.

Mayer, in Landwirtschaftliche Jahrbücher of December 18, gives

a translation of an article by Giltay on the method of teaching botany

in the agricultural academy at Wageningen.

A biographic sketch of Errera, by Massart, with an excellent por-

trait and a list of his publications, has been issued from the Hayez

press of Brussels.

An illustrated account of the Desert Botanical Laboratory at Tucson

is contributed by Cannon to Out West for January.

The third annual issue of part M, Botany, of the International

Catalogue of Scientific Literature was issued in September by the

Royal Society of London,— the manuscript having been completed

in February last. It forms an octavo volume of 909 pages.

A photographically illustrated article on soil formation, by Fletcher,

is published in Country Lije in America for January.

— Pammel has distributed an interesting paper comparing certain

swamp, clay, and sandstone floras, — separately printed from vol. 10

of the Proceedings of the Davenport Academy of Sciences.

The flora of one of the “Chouteau buttes” of Missouri is analyzed

by Standley in vol. 1, part 2, of the Bulletin of the Bradley Geological

Field Station of Drury College.

A list of additions and corrections to Fleet’s list of Mt. Rainier

plants is published by Piper in Mazama of December last.

An illustrated account of the vegetation of the Bahamas, with a

list of the species so far known as occurring on them, is separately

670 THE AMERICAN NATURALIST [Vor. XL

issued by the author, Professor Coker, from Shattuck’s The Bahama

Islands, published by the Geographical Society of Baltimore.

The concluding parts of Macloske’s “Flora Patagonica," forming

part 5 of volume 8 of the Reports of the Princeton University Expedi-

tions to Patagonia, 1896-1899, have recently been issued.

A paper on the alpine flora of northern Argentina, by R. E. Fries,

is published as the opening number of series 4, vol. 1, of the Nova

Acta R. Societatis Scientiarum. U psaliensis.

The third of Merrill’s papers on “New or Noteworthy Philippine

Plants," and a paper on the source of Manila “elemi,” form no. 29

of the publications of the Bureau of Government Laboratories, of Manila.

The Flora oj Tropical Africa, under the editorship of Sir William

T. Thiselton-Dyer, reaches into Convolvulacee in the recently

issued vol. 4, sect. 2, part 1

An account of the botany of northwestern New South Wales is.

given by Turner in vol. 30 of the Proceedings of the Linnean Society

of that country. ;

A colored plate of Sarracenia flava accompanies an article on the

genus in Flora and Sylva for November.

An illustrated account of garden Sarracenias, by Vollbracht, is

published in the Wiener Illustrierte Garten-Zeitung for December.

An illustrated monograph of the Uromyces forms of Bauhinia is

published by Westergren in no. 4 of the Arkiv för Botanik of 1905.

Data on the bud-rot of Cocos are given in vol. 6, no. 3, of the West

Indian Bulletin.

Vol. 22, part 2 (the second fascicle issued), of the North American:

Flora under the editorship of Professors Underwood and Britton,.

includes Saxifragaceze (Small), Hydrangeacee (Rydberg), Cunoni-

acer, Iteacee, Hamamelidacee (Britton), Pterostemonaceze (Small),

Altingiacee (Wilson), and Phyllonomacez (Rusty). It bears date

December 18.

A geographic-systematic account of North American Saxifragine

is published by Rosendahl as asupplement to vol. 37, part 2, of Engler’s

Botanische Jahrbiicher, issued in December.

A new northern Antennaria is described by Greene in The Ottawa

Naturalist of January.

No. 477] NOTES AND LITERATURE 671

Habit and bark photograms of Quercus rubra are published in

Forest Leaves for December.

The Journal of Botany tor January contains a revision of Cerato-

stigma by the new Director of the Kew Gardens, Col. Prain.

The geographic distribution of Ulmacee is being analyzed by

Bernard in current numbers of the Bulletin de l Herbier Boissier.

An analysis of the subgenera of Ribes, with a detailed account of

the first of these, Parilla, is separately issued by Janczewski from the

Bulletin International de l' Académie des Sciences de Cracovie.

Dahlstedt gives an illustrated account of the Scandinavian forms

of Taraxacum in Botaniska Notisser for 1905.

Floral teratology in two species of Salix is discussed by Mott in vol.

2, no. 7, of the University of California Publications, Botany.

A monograph of the willows of Ohio, by Griggs, forms vol. 4, part 6,

of the Proceedings of the Ohio State Academy of Science.

Two new aloes are described and figured by Schönland in the

Gardeners’ Chronicle of December 2.

Kinetostigma is the name proposed by Dammer, in no. 36 of the

Notizblatt des k. botanischen Gartens und Museums zu Berlin, for a

Chameedorea-like Guatemalan palm genus.

A. Usteri re-analyzes the morphology of the Coniferous ament in

the light of some new Cunninghamia material, in the Revista da

Sociedade Scientifica de Sao Paulo of September last.

Christensenia is proposed by Maxon, to replace the generic name

Kaulfussia in Marattiacex, in the Proceedings of the Biological Society

of Washington of December 9, in which he also describes a new Lyco-

podium from Guatemala.

The Fern Allies of North America North of Mexico is the title of a

new book by Clute recently issued from the Stokes Press of New York.

It is illustrated very fully and well.

Setchell gives an account of the parasitic Floridex of California, in

Nuova Notarisia for April.

A neat little pamphlet on “Lichenology for Beginners" has been

separately printed from The Bryologist by F. L. Sargent, and is offered

by the Harvard Coöperative Society of Cambridge.

672 THE AMERICAN NATURALIST [Vor. XL

The fungi of the Belgian Antarctic Expedition are described by

Madame Boinmer and Madame Rousseau in a separate recently

issued from the Buschmann Press of Antwerp.

A paper on pathogenic species of Aspergillus is published by Con-

stantin and Lucet in series 9, vol. 2, no. 1-3, of the Annales des Sciences

Naturelles, Botanique. |

A paper on the Pyrenomycetex of Orleans Co., N. Y., by Fairman,

constitutes a brochure of vol. 4 of the Proceedings of the Rochester

Academy of Sci:nce, recently issued.

An illustrated paper by House on the fungi and bacteria of plant

diseases forras Circular no. 18 of the Estacion Central Agronomica

of Cuba.

An Alternaria rot of apples is described by Longyear in Bulletin 105

of the Agricultural Experiment Station of Colorado.

A monograph of the apples of New York, by Beach, Booth, and

Taylor, constituting part 2 of the Report of the New York Agricul-

tural Experiment Station jor 1903, recently issued, forms two octavo

volumes, illustrated by numerous plain and colored plates.

Alcocer has begun the publication of a paper on the fruits of Mexico

in current issues of the Anales del Museo Nacional de Mexico.

An illustrated popular account of the tobacco industry of the United

States is given by Willey in The American Inventor for December. _

Montgomery argues, in The Popular Science Monthly for January,

that Zea and Euchlena may have had a common origin, the central

spike of a tassel-like structure developing into the ear in the former,

and its lateral branches giving rise to the clustered pistillate spikes of

teosinte.

Results of corn selection are given by Lyon in Bulletin no. 91 of the

Agricultural Experiment Station of Nebraska.

An account of raffia and its preparation, by Deslandes, has recently

appeared from the press of Challamel of Paris.

A lecture on heredity and the origin of species, by MacDougal, is

separately distributed from The Monist for January.

Notes on the Life History of British Flowering Plants is the title of a

volume by Lord Avebury, recently issued from the Macmillan Press.

No. 477] NOTES AND LITERATURE 673

Harris’s conclusions on the influence of Apidz on the geographical

distribution of certain floral types are restated in The Canadian.

Entomologist, October to December.

Foliage phenology in Ceylon is discussed by Wright in vol. 2, part 3,

of Annals of the Royal Botanic Gardens, Peradeniya.

A portrait of the retiring Director of Kew Gardens, Sir W. T.

Thiselton-Dyer, is published in the Gardeners’ Chronicle of December 9.

A short biographic sketch of Tschirch, with portrait, is published

in the American Journal of Pharmacy for January.

The October number of the Nuovo Giornale Botanico Italiano is

dedicated to the memory of Delpino, whose portrait forms its frontis-

piece.

A catalogue of plants cultivated in the Vilmorin Gardens forms an

appendix to the 1904 volume of the Bulletin de la Société Botanique

de France,— recently issued.

The Journals.— Botanical Gazette, December:— Atkinson, “Life

History of Hypocrea alutacea" ; Transeau, “The Bogs and Bog Flora

of the Huron River Valley"; Bergen, “Tolerance of Drought by

Neapolitan Cliff Flora"; Lyon, “A New Genus of Ophioglossacese

[Sceptridium].”’

Botanical Gazette, January:— Chrysler, “ The Nodes of Grasses”;

Transeau, “The Bogs and Bog Flora of the Huron River Valley”;

Merriman, “Nuclear Division in Zygnema”; Breazeale, “Effect of

Certain Solids upon the Growth of Seedlings in Water Cultures”’;

Hitchcock, ‘‘Notes on North American Grasses — V"; Farmer,

"Sporogenesis in Pallavicinia"; Moore, “Reply [to the foregoing].’

Bulletin of the Torrey Botanical Club, November: — Howe, “ Phy-

cological Studies — II"; Underwood, “The Genus Aleicornium of

Gaudichaud”; Rydberg, “Studies on the Rocky Mountain Flora —

XV”; Osterhout, “New Plants from Colorado”; Hastings, ** Obser-

vations on the Flora of Central Chile.”

Bulletin of the Torrey Botanical Club, December: — Murrill, “The

Polyporacem of North America — XIII"; Rydberg, “Astragalus and

its Segregates as Represented in Colorado.’

Bulletin of the Torrey Botanical Club, January: — Evans, " Hepaticee

of Puerto Rico — VI”; Arthur, “New Species of Uredinee — IV”;

Underwood, “The Genus Stenochlena "; Small, “Studies in North

American Polygonacee — II.”

674 THE AMERICAN NATURALIST [Vor. XL

The Bryologist, January: — Fink, “Edward Tuckerman — A Brief

Summary of his Work” (with portrait); Merrill, “Lichen Notes No.

2”; Haynes, “Cephalozia francisci."

The Fern Bulletin, October: — Nichols, “ Schizea pusilla in Cape

Breton"; Woolson, “A Precocious Cystopteris”; Gilbert, ‘‘Obser-

vations on North American Pteridophytes — II"; Klugh, “ Scolo-

pendrium vulgare in Ontario”; Davenport, ‘‘Reversions and their

Fluctuations”; Gilbert, “Mrs. Taylor's Georgia Ferns”; Clute, “A

Check List of the North American Fernworts.”

The Iowa N aturalist, October: — Cratty, “ The Juncacez of Iowa";

Fitzpatrick, “ The Melanthacez of Iowa."

Journal of Mycology, September: — Morgan, “North American

Species of Marasmius"; Beardslee, “The Amanitas of Sweden”;

Kellerman, “Index to North American Mycology.”

Journal of Mycology, November: cem “North American

Species of Marasmius” (continued); Atkinson, ‘The Genera Balansia

and Dothichloé in the United States, with a Consideration of their

Economic Importance"; Sumstine, “ Another Fly Agaric”; Holway,

* Notes on Uredineee — IV"; Sturgis, “Remarkable Occurrence of

Morchella esculenta”; Kellerman, “Notes from Mycological Litera-

ture — XVII.”

Journal of the New York Botanical Garden, November: — Nash,

“Further Explorations in the Republic of Haiti.”

Journal of the New York Botanical Garden, December: —- Murrill,

*' Collecting Fungi in Maine.”

Journal oj the New York Botanical Garden, January: — Berry,

*' Fossil Plants along the Chesapeake and Delaware Canal"; Nash,

“The Coco de Mer, or Double Cocoanut”; Hollick, “Origin of the

Amber found on Staten Island.”

The Ohio Naturalist, December: — Gleason, “Notes from the Ohio

State Herbarium — V"; Schaffner, J. H., “Key to the Ohio Dog- `

woods in the Winter Condition"; Schaffner, Mabel, “ Free-Floating

Plants of Ohio." _

The Ohio Naturalist, dd — Tillman, “ The Embryo-sac and

Embryo of Cucumis sativus”; Kellerman, York, and Gleason, “ An-

nual Report on the State Herbs for the Years 1903, '04 and ’05”;

Sterki, "Some Notes on Martynia"; Hillig, *A New Case of Muta-

tion [Commelina nudiflora]"; Schaffner, “Additional Observations

on Self-pruning."

No. 477] NOTES AND LITERATURE 675

The Ottawa Naturalist, December: — Greene, ‘On so-called Silene

menziesii”; Fernald, “An Alpine Variety of Cnicus muticus”;

Fernald, “A New Goldenrod from the Gaspé Peninsula”; Macoun,

“Two Rare Fungi [Cyclomyces greeni and Pleurotus subareolatus].”

The Plant World, October: — Leavitt, “The Defences of the Cock-

spur Thorn”; Atkinson, ‘‘Outlines for the Observation of Some of

the More Common Fungi" (conclusion); Gray, "Variations in

Trillium.”

The Plant World, November: — Brackett, “The Mistletoe: Some

Recent Observations on its Habit and Structure”; Harshberger, ‘ The

Plant Formations of the Catskills”; Bailey, W. W., “How New Plants

come in."

The Plant World, December: — Goebel, “Wilhelm Hofmeister”

(with portrait); Klugh, “Notes on the Ferns of North-Central On-

tario"; Harper, “A Peculiar Hygroscopic Movement in the Capsules

of Kneiffia”; Clute, “The Defenses of the Cock-spur Thorn: An-

other Interpretation.”

Rhodora, November: — Brainerd, “The Use of Accentual Marks

in Gray’s Manual”; Fernald, “An Alpine Adiantum”; Sargent,

"Recently Recognized Species of Crategus in Eastern Canada and

New England — VI”; Robinson, “A New Ranunculus from North-

eastern America”; Collins, ‘Phycological Notes of the late Isaac

Holden — II"; Greenman, “Senecio balsamite Muhl., var. firmi-

jolius”; Fernald, “A Pale Form of Avena striata.”

Rhodora, December: — Brainerd, “Notes on New England Violets

— III”; Fernald, “A Northern Cynoglossum”; Cushman, “A

Contribution to the Desmid Flora of New Hampshire” (continued).

Rhodora, January: — Ames, “ Habenaria orbiculata and H. macro-

phylla”; Brainerd, “Hybridism in the Genus Viola — II"; Fernald,

“A New Geum from Vermont and Quebec”; Davenport, “A Hy-

brid Asplenium New to the Flora òf Vermont”; Ames, “Spiranthes

ovalis”; Blanchard, “A New Rubus from Connecticut”; House,

“Observations upon Pogonia (Isotria) verticillata”; Fernald, “A

Handsome Willow of the Penobscot Valley”; Brainerd, “ Nephro-

dium filix-mas in Vt.” ; Woodward, “Notes on Two Species of Sporo-

bolus.”

Torreya, November: — Harshberger, “The Plant Formations of

the Adirondack Mountains"; Murrill, *A Key to the Brown Sessile

676 THE AMERICAN NATURALIST [Vor. XL

Polyporex® of Temperate North America”; Taylor, “On the Occur-

rence of Daucus carota in Taiti”; Murrill, “ Tomophagus for Den-

drophagus"; Kellerman, “The Gray Polypody in Ohio”; Cockerell,

“A Laciniate Rubus”; Macloskie, “ Duplex Names.”

Torreya, December: — Harper, “A Statistical Method for Com-

paring the Age of Different Floras”; Kraemer, “ Artificial Coloring

of Flowers”; Murrill, “A Key to the Agaricez of Temperate North

America"; Britton, “The Cuban Columneas"; Bates, “Astragalus

lotiflorus nebraskensis" ; Cannon, “A Curious Cactus Fruit.”

Torreya, January: — Andrews, “Polarity in the Weeping Willow";

Gleason, ‘‘ Notes on some Southern Illinois Plants — III"; Rydberg,

“Grayia or Eremosenium"; Cockerell, “Rhus and its Allies."

The fourth Year Book of the Carnegie Institution of Washington,

recently issued, contains abstracts of the reports of investigators to

whom grants have been made for botanical research.

The following botanical papers, or abstracts of them, are contained

in the Report of the Eighth Geographie Congress (Washington, Govt.

Printing Office, 1905) :— Cowles, “ A Remarkable Colony of Northern

Plants along the Apalachicola River, Florida. and its Significance";

Cowles, “The Importance of the Physiographie Standpoint in Plant

Geography"; Harshberger, “Methods of determining the Age of the

Different Floristic Elements of Eastern North America"; Drude,

"Die Methode der pflanzen-geographischen Kartographie, erläutert

an der Flora von Sachsen”; Anderson, **'The Flora of Connaught

as Evidence of the Former Connection with an Atlantic Continent";

White, “The American Range of the Cycadofilices."

PUBLICATIONS RECEIVED

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ANDREWS, M. R. S. Bob and the Guides. New York, Charles Scribner’s

Sons, 1906. 8vo, 351 pp., illus. $1.50.— Freeman, E. M. Minnesota Plant

Diseases. St. Paul, Minn. xxiii + 432 pp., illus.— Hemenway, H.

Hints and Helps for Young Gardeners. Hartford, Conn., Published by the

Author, 1906. 8vo, 59 pp., illus. $.35.— Hower, R. H., JR., AND M. A.

Common and Conspicuous Lichens oj New England. Part I. Boston, W. B.

Clarke and Co., 1906. 12mo, pp. 1-22, illus. $.50.— Howe, R. H., JR., AND M.

Common and Conspicuous Lichens of New England. Part 2. Boston,

W. B. Clarke and Co., 1906. 16mo, pp. 23-39, illus. $.50.— LACOUTURE, C.

Hepatiques de la France. Tableaux synoptiques des caractéres saillants des

tribus, des genres et des espèces. Paris, Paul Klincksieck, 1 1905. 4to, 78 pp.,

illus.— Lorsy, J. P. Vorlesungen über Deszendenztheorien mit besonderer

Berücksichtigung der botanischen Seite der Frage. Erster Teil. Jena, G.

Fischer, 1906 [1905]. Svo, xii + 384 pp., 2 pls., 124 figs. 8 Mk.— McMur-

RAY, C. A. Special Method in Elementary Science for the Common School.

New York, The Macmillan Co., 1905. 12mo, ix + 275 pp.— p i KH.

x+329 pp. $1.00.— PRaATT, H.S. A Course in Vertebrate es A u.

to the Dissection and Comparative Study of Vertebrate Animals.

Ginn and Co., 1905. 8vo,x + 299 pp.— SABINE, W. C. A Student comet

of a Laboratory Course in Physical Measurements. Revised Edition. Boston,

Ginn and Co., 1906. 8vo, vi + 97 pp. $1.25.— ScnuiLuiNes, C. G. With

Flash-light and Rifle. Photographing by Flash-light at Night the Wild Animal

World of Equatorial Ajrica. Translated and abridged by Henry Zick, Ph. D.

New York, . and Brothers, 1905. 8vo, xiii + 421 pp., illus.— WILLson,

R. W. oratory Astronomy. Boston, Ginn and Co., 1905. ix + 175 pp.,

figs. $1. re — ZSCHIMMER, E. Eine Untersuchung über Raum, Zeit und

Begriffe vom Standpunkte des Positivismus. Leipzig, W. Engelmann, 1906.

8vo, 54 pp. Mk. 1.20.

ApaMs, G. E. Trial of — of Potatoes. R. I. Agric. Exp. Sta., bull.

111, pp. 63-74.— ALLEMANDET, G. H. Analyses des échantillons dean de

mer recueillis pendant la anes du yacht “ Princesse-Alice” en 1905.

Bull. Mus. Océanogr. de Monaco, no. 54, 11 pp.— ANDERSEN, K n

Bats of the Genus Rhinolophus, collected by Dr. W. L. Abbott in the Islands

of Nias and Engano. Proc. U. S. Nat. Mus., vol. 29, pp. 657-659.— ARE-

CHAVALETA, J. Apuntes botánicos. Anales Mus. Nac. de Montevideo, ser.

2, entrega 3, pp. 17-57, 11 pls., 10 figs — Arkınson, G. F. Life History of

Hypocrea alutacea. Bot. Gaz., vol. 40, pp. 401-417.— Arkınson, G. F. The

Genera Balansia and Dothichloé in the United States with a Consideration

of their Economic Importance. Journ. Mycology, vol. 11, pp. 248-267, pls.

81-88.— Bancrort, F. W. On the Validity of Pflüger's Law for the Gal-

677

678 THE AMERICAN NATURALIST [Vor. XL

— eo. of Paramecium. Univ. i Calij. Publ., Physiol., vol. 2,

pp. 193-215.— Bancrort, F. W. The Control of Galvanotropism in Para-

mecium is surdi Substances. Univ. of Calif. Publ., Physiol., vol. 3, pp.

1-31.— Banta, A. M., anp McATEE, W. L. The Fife PAM of the Cave

Salamander. Spelerpes maculicaudus (Cope). Proc. U. S. Nat. Mus., vol. 30,

p. 67-83, pls. 8-10.— Basster, R. S. A Study of the James Types of

Ordarilan and Silurian Bryozoa. Proc. U. S. Nat. Mus., vol. 30, pp. 1-66,

pls. 1-7.— BELL, W. B. Modifications in Size, Form, and Function of Homol-

ogous Crustacean Appendages. Iowa City, 39 pp., 13 pls.— BERGER, E. W.

Habits and Distribution of the Pseudoscorpionide, principally Chelandg

oblongus Say. Ohio Nat., vol. 6, pp. 407-419, pl. 28 BE j A

Cours d’ océanographie fondé à Paris par S. A. S. le Prince Albert de Maniot

(Deuxième année.) Bull. Mus. Océanogr. de Monaco, no. 57, 18 pp.— BERGET,

A. Cours d’océanographie fondé à Paris par S. A. S. le Prince Albert de

Monaco. (Deuxième année.) Phénomènes d’interférences.— Seiches. Bull.

Mus. Océanogr. de Monaco, no. 61, 18 pp.— BERGET, A. Cours Poto

graphie fondé à Paris par S. A. S. le Prince Albert de Monaco. Les marées.

Bull. Mus. Océanogr. de Monaco, no. 68, 19 pp.— Bıruınss, J. S. The Physi-

ological Aspects of the Liquor Picks, Boston and New York, 26 pp.—

Bouvier, E. L. Nouvelles observations sur les Glaucothoés. Bull. Mus

‚1 fig — BERGE

Océanogr. de Monaco, no. 51, pp.— Bouvier, E. L. Sur les aai

décapodes recueillis par le yacht doit vag e cours de la ———

de 1905. Bull. Mus. Octanogr. de Monaco, no p.— CAUDELL, A. N.

The Locustide and Gryllide (Katydids ipi Peso ee n WE

Foster in Paraguay. Proc. U.S. Nat. Mus., vol. 30, pp. 235-244.— CHAPMAN,

GiS -A Working Plan for Forest Lands in Be: Chien South Carolina.

U. S. Dept. Agric., Bur. Forestry, bull. 56, 62 pp., 4 pls., map.— CHEVALLIER,

A. Courants marins profonds dans l'Atlantique nord. Bull. Mus. Occanogr.

de Monaco, no. 63, 16 pp., 3 pls.— CHEvrevx, E. Description d'un amphi-

pode pélagique nouveau comme genre et comme espèce. Bull. Mus. Océanogr.

de Monaco, no. 49, 5 pp., 2 figs.— CLOTHIER,G.L. Advice for Forest Planters

in Oklahoma ipse Adjacent Regions. U. S. Dept. Agric., Forest Service,

bull. 65, 46 pp., 4 pls.— Coss, N. A. The Inspection and Disinfection of

Cane Cuttings. Rept. Exp. Sta. Hawaiian Sugar Planters’ Assoc., Div. Path

and Phys., bull. 1, 35 + vi pp., 8 pls.— Cor, W. R. Nemerteans of the

wa Islands collected by the Steamer Albatross in 1902. Bull. U. S.

Fish Comm. jor 1903, pt. 3, pp. 975-986, pl. 1.— Coox, O. F. The Vital

Fabrie of Déséent: Proc. Washington Acad. Sei., vol. 7, pp. 301-323.—

CovriERE, H. Note préliminaire sur les Eucyphotes recueillis par S. A. S.

: e. € ‚ 10 pp.— Dury, €. Ecological

Notes on some Coleoptera of the Cincinnati Region, including Seven New

pe rn. Cincinnati Soc. Nat. Hist., vol. 20, pp. 251-256.— Dury, C.

Additions to the List of Cineinnati Coleoptera. i ; ‘at.

Hist., vol. 20, pp. 257-260.— Exo, D. G. A Check List of Mammals of the

North American Continent, the West Indies, and the Neighboring Seas.

No..477] PUBLICATIONS RECEIVED 679

Field Columbian Mus., zoöl. ser., vol. 6, 761 pp.— Europ, M. J., AND MALEY,

The Butterflies of Montesa: Univ. of Montana, bull. 30 (biol. ser. no.

10), xvii + 175 pp., 13 pls., 117 figs — Esterty, C. O. Some Observations

on the Nervous System of Copepoda. Univ. of Calif. Publ., Zoöl., vol. 3, pp.

1-12, pls. 1-2.— Farrman, C. E. The Pyrenomycetex of Orleans County,

N. Proc. Rochester Acad. Sci., vol. 4, pp. 165-191, figs. 1-6.— FLEMING,

B. P. Duty of Water. Wyo. Exp. Sta., bull. 67, 20 pp.— Fur, J. M.

Contribution to is — AS of the Pacifie. Bull. U. S. Nat. Mus.,

no. 55, 62 pp., pls.— Fores, S. A. Twenty-third Report of the State

Entomologist on = Noxious an Beneficial Insects of the State of Illinois.

Twelfth Report of S. A. Forbes. viii + 273 + x-xxxiii pp., 7 pls., 236 fi

Forest Service, The: What it is and how it deals with Forest Puit

U. S. Dept. Agric., Forest Service, circ, 36, 24 pp.— GANDAR A,G. Destruccion

de los caracoles y de los tlaconetes. Com. de Parasitol. eec eirc. 31, 7 pp.,

gs.— GANDARA, G. El ld bordeles. Com. Parasitol. Agric., circ. 35,

9 pp.— Giptey, J. W. A Fossil Raccoon from a California Pleistocene Cave

Deposit. Proc. U. S. Nat. Mus., vol. 29, pp. 553-554, pl. 12.— GIDLEY, ^ x

A New Ruminant from the Pleistocene of New Mexico. Proc. U. S. Nat.

Mus.; vol. 30, pp. 165-167.— Grant, U. S. Report on the Lead and Zine

Deposite of Wisconsin, with an Atlas of Detailed Maps. Wise. Geol. and Nat.

Hist. Surv., bull. 14, ix + 100 pp., pls. 19-26, atlas.— GRAZING ON THE Prs-

tuc Lanps. Extracts from the Report of the Public Lands Commission.

U. S. Dept. Agric., Forest Service, bull. 62, 67 pp., 2 ma aps.— GUDGER, E. W

The Breeding Habits and the — of the Egg of the Pipefish, Sipho-

stoma floride. Proc. U. S. Nat. Mus., vol. 29, pp. 447-500, pls. 5-11.—

Guérin, M. J. Notes priiininites surles gisements de mollusques comes-

tibles des cótes de France.— Le Golfe du Calvados. Bull. Mus. Océanogr. de

Monaco, no. 67, 32 pp., 2 pls., map.— HaxpLmscH, A. A New Blattoid

from the Cretaceous Formation of North America. Proc. U. S. Nat. Mus.,

vol. 29, pp. 655-656.— HANDLIRSCH, A. Revision of American Paleozoic

Insects. Proc. U. S. Nat. Mus., vol. 29, pp. 661-820, 109 figs.— HENRIKSEN,

M. E. A Functional View of Development. Biol. Centralbl., vol.

18-37.— HxnarsELL, H. Ascensions de ballons en pleine mer, pour étailier

les conditions de température et d’humidité, ainsi que les courants atmos-

er jusqu'à des altitudes trés élevées de Vatmosphére. Bull. Mus

Océanogr. de Monaco, no. 50, 10 pp.— HERG Sur une exploration

de Vitas ibis libre au-dessus de l'Océan Atlantique au nord des ons

tropicales, en 1905. Bull. Mus. Océanogr. de co, no. 53, 5 pp.— HÉR-

ovaRp, E. Sur Pelagothuria bouvieri epis pélagique nouvelle) re-

cueillie pendant la campagne du yacht “ Princesse-Alice” en 905. Bull

Mus. Océanogr. de Monaco, no. 60, 5 PP-, 1 fig— Herre, A. W. C. T. The

oFliaceous id Fruticose Lichens of the un Cruz Peninsula, California.

. 325-396.— Hunter, W. D. Medios

Shanghai and Hongkong, China. Proc. U. S. Nat. Mus., vol. 29, pp. 517-529.

— Jorpan, D. S., AND SEALE, A. Descriptions of Six New Species of Fishes

680 THE AMERICAN NATURALIST [Vor. XL

from Jap Proc. U. S. Nat. Mus., vol. 30, pp. 143-148.— Jousın, L.

Cours d’ EN fondé à Paris par S. A. S. le Prince Albert de Monaco.

isti année.) Les larves et les métamorphoses des animaux marins.

. Mus. Océanogr. de Monaco, no. 58, 35 pp., 36 figs.— Jounin, L. Notes

tina sur les gisements de mollusques comestibles des cótes de France.

— Les cótes de la Loire à la Vilaine. Bull. Mus. Océanogr. de Monaco, no.

59, 26 pp., 2 pls., map.— Jounin, L. Cours disélancimpis fondé à Paris

ou S. A. S. le Prince Albert de Monaco. Les ecelentérés. Bull. Mus. Océan-

r. de Monaco, no. 66, 38 pp., 38 figs.— Jousın, L. Cours d'océanographie

fondé à Paris par S. A. S. le Prince Albert de Monaco. Considérations sur la

faune des cötes de France. La répartition des animaux dans ses rapports

avec la nature des Pit ages. Les côtes rocheuses. Bull. Mus. Océanogr. de

Monaco, no. 71, 26 pp., 3 pls., 22 figs.— KELLOGG, R. S. Forest Belts of

Western Kansas and Mni U. S. Dept. Agric., Forest Service, bull. 66,

44 pp., 6 pls., map.— Krases, E. A. On the Syntomid Moths of Southern

Venezuela ee in 1898-1900. Proc. U. S. Nat. Mus., vol. 29, 531-

552.— KoEHLER, R., er Vaney, C. Description d'une RUE wa

d’astérie en trés vraisemblablement à une forme abyssale, (Stello-

sphera mirabilis). Bull. Mus. Océanogr. de Monaco, no. 64, 10 pp., 5 figs.—

Kororp, C. A. Dinoflagellata of the San Diego Region.— 1. On Hetero-

dinium, a New Genus of the Peridinide. Univ. of Calij. Publ., Zoól., vol. 2,

pp. 341-368, pls. 17-19.— Lampe, L. M. Description of New Species of

Testudo and Bena with Remarks on some Cretaceous Forms. Ottawa Nat.,

vol. 19, pp. 187-196, pls. 3-4.— Lampe, L. M. Boremys, a New Chelonian

Genus from the Cretaceous of Aliena: Ottawa Nat., vol. 19, pp. 232-234.—

LivpaAHL, J. Orthography of the Names of the Naiades. Journ. Cincinnati

Soc. Nat. Hist., vol. 20, 235-243.— MacGiiuivray, A. D. A Study of the

Bde of the Tenthredinoidea, a rn of Hymenoptera. Proc. U. S

at. Mus., vol. 29, pp. 569-654, pls. 21-44.— Macıas, C. “La nitragina.’”

Manera de aumentar las cosechas de frijol, hava, alfalfa, garbanzo y lenteja.

Com. de Parasitol. Agric., cire. 30, 5 pp.— MEEK, S. E. An Annotated List.

of a Collection of Reptiles from Southern California and Northern Lower :

California. Field Columb. Mus., zoól. ser., vol. 7, no. 1, pp. 1-19, pls. 1-3. —

Meraz, A. Elbarrenillo del Chile. Com. de Pa risitol. ipis: circ. 33, 4 pp.—

MILLER, G. S., Jk. The Monkeys of the Macaca nemestrina Group. Proc.

U. S. Nat. Mus., vol. 29, pp. 555-563, pls. 13-22.— MırıspauGH, C. F. Pre-

nuneie Bahamenses — I. Contributions to a Flora of the Bahamian Archi-

pelago. Field Columbian Mus., bot. ser., vol. 2, pp. 137-184.— Monaco, A.

DE. Considérations sur la biologie marine. Bull. Mus. Occanogr. de Monaco,

no. 56, 14 pp.— Monaco, A. DE. Sur la septiéme campagne scientifique de

la Princesse-A lice. Bull. Mus. Océanogr. de Monaco, no. 69, .— Morton,

des eaux sur la production du plankton marin. Bull Mus. Océ nogr.

Monaco, no. 62, 12 pp.— Prosser, C. S. Revised Nomenclature of the Ohio

Geological Formations. Geol. Surv. Ohio, ser. 4, bull. 7, xv + 36

RaTHBUN, M. J. The Brachyura and Macrura of the Hawaiian falas.

Bull. U. S. Fish Comm. for 1903, pp. 827-930, pls. 1-24.— Rz», F.

Working Plan for Forest Lands in Central Alabama. U. S. Dept. Agric.,

No. 477] PUBLICATIONS RECEIVED 681

Forest Service, bull. 68, 71 pp., 4 pls.— REHw, J. A. G. Notes on Exotic

Forficulids or Earwigs, with Descriptions of New — Proc. U. S. Nat

Maus., vol. 29, pp. 501-505, 9 figs.— RıcHArD, J. Sur

a la tétolie et à l'examen préliminaire du plankton an et sur la

présence du genre Penilia dans la Méditerranée. Bull. Mus. Océanogr. de

Monaco, no. 52, 12 pp., 1 pl— RıcHArpson, H. A Monograph on the Isopods

of North America. Bull. U. S. Nat. Mus., no. 54, liii + 727 pp., 740 figs.—

Ricwarpson, H. Description of a New Species of Livoneca from the Coast

of Panama. Proc. U. S. Nat. Mus., vol. 29, pp. 445-446, 2 figs.— SARGENT,

L TA for Penn. The Bryologist, vol. 8, 20 pp., illus.—

Sans, G. O. An Account of the Crustacea of Norway with Short Descriptions

and Figures of all the Species. Vol. 5, Copepoda Harpacticoida. Bergen

M useum diu , pp. 109-132, pls. ee W. Descriptions of ed

South American Moths. Proc. U. S. Nat. Mus., vol. 30, pp. 85-14

ScHULLER, R. R. Primera cinke 2 pepe i la cartografia roam

icana. Anales Mus. Nac. de Montevideo, vol. 2, pp. 1-59.— SEURAT, L. G.

Cours d’océanographie fondé à Paris par S. A. S. le Prince Albert de Monaco.

Les iles coralliennes de la Polynésie. $Structure.— Mode de formation.—

Faune et flore. Bull. Mus. Océanogr. de Monaco, no. 65, 16 pp.— SHUFELDT,

R. W. Double-headed Animals. Western Field, vol. 8, p. 117.— SMITH,

B. Senility among Gastropods. Proc. Acad. Nat. Sci. Phila, 1905, pp.

345-361, pls. 30-31.— SwrrH, F. Notes on Species of North American

Oligochæta. V. The Systematic Relationships of Lumbriculus (Thino-

rilus) inconstans (Smith). Bull. Ill. State Lab. Nat. Hist., vol. 7, pp.45-51.—

nn S. N. The Natural Replacement of White Pine on Old Fields in

New England. U. S. Dept. Agric., Bur. Forestry, bull. 63, 32 pp., 4 pls., map.

— STEINEGER, L. A New Lizard of the Genus Phrynosoma, from Mexico.

Proc. U. S. Nat. Mus., vol. 29, pp. 565-567.— SroxE, W. Ona Collection of

Birds and Mammals from the Colorado Delta, Lower California. With Field

Notes by Samuel N. Rhoads. Proc. Acad. Nat Sci. Phila., 1905, pp. 676-690.—

Mr. George L. Harrison, Jr. Proc. Acad. Nat. Sci. Phila., 1905, pp. 755-782.—

Terry, F. W. Leaf-hoppers and their Natural Enemies. Parts 5, 6. Rep.

Exp. Sta. Hawaiian Sugar Planters’ Assoc., Div. Ent., bull. 1, pp. 163-205,

pls. 8-13.— UrnicH, E. O., AND BASSLER, R. S. New American Paleozoic

Ostracoda. pe and Descriptions of Upper Arne Genera and

Species. Proc. U. S. Nat: Mus., vol. 30, pp. 149-164, pl. 11.— Warp, H. A.

Great hes Collections and their Composition. ci ‘Rothe ier Acad,

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Rochester page) Sci., vol. 4, pp. 193-202, pl. 19.— WHEELER, H. J., Brown,

BE å p HoGENSON 040 A Comparison of Results obtained by the

Method ot pec in Paraffined Wire Pots with Field Results on the same

Soil. R. I. Agric. Exp. Sta., bull. 109, pp. 15-44.— WHEELER, H. J., HART-

WELL, B. L., WessEts, P. H., ann Gray, J. P. Commercial Fertilizers. R. I.

Agric. Exp. Sta., bull. 110, pp. 47-60.— WriLLIiAMSON, Mrs. M. B. Some West

American Shells including a New Variety of Corbula luteola Cpr. and two New

Varieties of Gastropods. Bull. So. Calif. Acad. Sci., vol. 4, pp. 118-129.—

Woopnvrr, L, L. An Experimental Study of the Life-history of Hypotrich-

ous Infusoria. Journ. Exp. Zoöl., vol. 2, pp. 585-632, pls. 1 1-3.— WUESTNER,

682 THE AMERICAN NATURALIST [Vor. XL

H. Pisolitie Barite. Journ. Cineinnati Soc. Nat. Hist., vol. 20, pp. 245-250.

— Zon, R. olly Pine in Eastern Texas, with Speni ial Reference to the

Production of Cross-ties. U. S. Dept. Agric., Forest Service, bull. 64, 53 pp.,

4 pls., 2

AGRICULTURAL JOURNAL OF INDIA, vol. 1, part 1.— AMERICAN MICROSCOPI-

CAL SocrETY. Transactions, vol. 26, 304 pp., 33 pls.— ANNALES DE PALEON-

TOLOGIE, vol. 1, pts. 1-2, 100 pp., 8 pls., figs.— BERGENs Museum. Aarbog,

1905, 2det Hefte.— British OnNrrHOLOGISTS' CLUB. Report on the Immi-

grations of Summer Residents in the Spring of 1905. Bull. B. O. C., vol. 17,

p., maps.— BUREAU or FisHERIESs. Report of the Commissioner of

Fisheries to the Secretary of Commerce and Labor for the Fiscal Year ended

June 30, 1905, document 52, 46 pp.— nn IMPERIAL DEPARTMENT OF

AGRICULTURE. Annual Report for 1904-1905, pp.— CINCINNATI SOCIETY

or NATURAL HISTORY. qun and title pages. Journal, vol. 20.— Eco-

NOMIC GEOLOGY, vol. 0. 2.— ENTOMOLOGICAL SOCIETY OF ONTARIO.

36th Annual Report, 1908, 143 vba 74 figs.— FIELD COLUMBIAN MUSEUM.

Annual Report of the Director to the Board of Trustees for the Year 1904—

1905. Field Columb. Mus., report ser., vol. 2, no. 5, pp. 333-435, pls. 61-71.—

FORESTRY AND IRRIGATION, vol. 11, nos. 11, 12; vol. 12, no. 1.— HESPERIAN,

a Western Quarterly Magazine, vol. 5, no. 1.— IMPERIAL CENTRAL AGRIC.

Exp. Sra., Japan. Bulletin, vol. 1, no. 1, 94 pp., 13 pls.— JOURNAL or GEOG-

RAPHY, vol. 5, nos. 1-4.— Minnesota. Tenth Annual Report of the State

Entomologist to the Governor for the Year 1905. Fourth Annual Report of

F. L. Washburn. xvii + 168 pp., 2 pls., 163 figs.— Le Mors SCIENTIFIQUE,

vol. 8, nos. 1-3.— MUSEUM OF THE BROOKLYN INSTITUTE OF ARTS AND SCI-

ENCES. Science Bulletin, vol. 1, no. 7, 186 pp.— Narura Novirares, vol.

nos . 28, no.

NATURAL, vol. 9, nos. 4, 5.— R. r rei Exp. Sta. Eighteenth Annual

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VOL. XL, NO. 478 OCTOBER, 1906

THE

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NATURALIST

A MONTHLY JOURNAL

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CONTENTS

Page

I. Naidide of Cedar Point, Ohio . PROFESSOR L. B. WALTON 683

II. Mechanism of the Odontophoral Means in Sycotypus canaliculatus

J. C. HERRICK 707

III. Notes and Literature: Biology, Loeb's Dynamies of Living Matter; Zoöl-

ogy, Capture of the Salamander, Autodax lugubris, at Los Angeles, Cal.

(L. H. Miller), Pimephales notatus 4n the Lower Susquehanna, (H. W.

Fowler), Notes; Botany, Notes, The Journals . . . 789

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THE

AMERICAN NATURALIST

Vou XL October, 1906 No. 478

NAIDID/E OF CEDAR POINT, OHIO

L. B. WALTON

THE microscopic annelids constituting the family Naidide of

the subclass Oligocheta are a group which has received little

attention in America. Michaelsen (:00) in his monograph of

the Oligochzta recognized 42 species from various parts of the

world and of that number only 6 were noted as occurring in our _

territory although observations made by Smith (:00) and noted

in the appendix (“Zusätze und Berichtigungen") increased the

number to 12. While this, taken in connection with the fact

that the observations have been confined almost entirely to two

localities, the one in Pennsylvania the other in Illinois, furnishes

sufficient justification for a review of the Naidide occurring at

Cedar Point, Ohio, some contemplated studies of a statistical

nature rendered a preliminary survey of several groups of fresh-

water organisms desirable for the purpose of ascertaining which

could be used most advantageously in the problems under con-

sideration. Consequently the present paper is purely from a

systematic standpoint, and although a considerable number of

specimens have been fixed, stained, and mounted, and a few im-

bedded and sectioned, no attention beyond that necessary to dif-

ferentiate the species has been given to anatomical or histological

structure.

In addition to the interest attached to the study of these organ-

isms upon the side of pure science, as outlined above, the fact

that they play a róle of decided economie importance must not

be overlooked. The relation of the microscopic organisms or

“‘ plankton,” accepting the definition in its broadest sense, to the

683

684 THE AMERICAN NATURALIST [Vor. XL

distribution of food fishes is a subject which has received increas-

ing attention during the past twenty years. Inasmuch as the

food of fishes is made up chiefly of small Crustacea, insect larvee,

minnows, etc., the existence of these being in turn dependent on

microscopic forms, among which the Naids occupy an important

position, it is evident that the distribution of such microscopic

organisms controls to a large extent the fish supply in any given

locality.

The somewhat unique location of Cedar Point with the open

lake on the north and a portion of Sandusky Bay extremely rich

in aquatic vegetation on the south, renders the Lake Laboratory

situated there a station particularly well adapted to the study of

the animal and plant life occurring in fresh water and to the inves-

tigation of the various problems of biological importance con-

nected therewith.

The present study was carried on at the laboratory during a

period of six weeks in July and August, 1905, the greater portion

of the time, however, being occupied with other work. Con-

sequently the record of species is undoubtedly far from complete,

although 10 species, 7 of them new to science, are noted. The

large proportion of new forms indicates the present condition in

regard to the systematic study of the Naids in the United States,

and while the writer has no wish to be classed as a “ species maker,”

nevertheless it is important to lay the foundations for future bio-

logical studies by first considering those groups containing indi-

viduals resembling each other sufficiently well to be called “species.”

The principal papers dealing with American Naids outside of

the excellent monographs of Michaelsen (:00) and Beddard (’95),

are those of Leidy (’50a, '50b, '52a, '52b, ’80), Minor (763), Reigh-

ard (’85), Cragin ('87), and Smith (96 and :00). In addition

to these, papers indispensable to the student of the group have

been published by Beddard, Benham, Bourne, Bousfield, Bret-

schner, Michaelsen, Tauber, and Vejdovsky, that of the last author

being classical in its morphological treatment of the forms. The

majority of these papers are either in the library of the writer, or

in the library of the department of biology of Kenyon College.

Mention should here be made of the courtesies extended by the

American Museum of Natural History, New York, the library

No. 478] OHIO NAIDIDE 685

of Cornell University, and the Museum of Comparative Zoölogy

of Harvard University, in the loan of literature otherwise inaccessi-

ble. I am furthermore greatly indebted to Samuel Henshaw of

the Museum of Comparative Zoölogy for noting certain references.

The studies of the various species were made primarily from

living specimens, all figures having been drawn with the aid of

the camera lucida at the magnification noted in each instance.

The most satisfactory method was that of transferring the Naid

from the culture by means of a pipette to a watch-glass and sub-

sequently to a drop of water on a slide, then placing over the drop

a cover-glass the margin of which was supported by an extremely

thin wooden wedge. After a time the specimens, without undue

compression, would become quiet and outline drawings could be

made with the camera. Specimens to be mounted were fixed

with hot sublimate-alcohol (sublimate 10 g., absolute alcohol

100 ce., distilled water 100 ce., acetic acid 2 cc.), stained in borax-

carmine, and eventually transferred to balsam, while those sec-

tioned were stained in hematin IA (Apathy) or in iron-hema-

toxylin (Heidenhain) after fixation in cold sublimate-alcohol.

The index of refraction of balsam approaches so closely the

refraction of the transparent sete that in order to study them

most advantageously it was found advisable to kill the specimens

by compressing them under the cover-glass and then at once to

make camera lucida drawings of the setz in the dorsal and ventral

bundles.

The Naididz are distinguished from the other families of the

Oligochzta primarily by the fact that their normal method of

reproduction is by means of budding, and that complete inter-

segmental dissepiments are present. The closely allied family

JEolosomatidz are without dissepiments and are usually of much

smaller size. Furthermore, the presence of colored “oil drops"

together with the absence of biuncinate setze are characters which

as a rule! will serve to distinguish these families. The Enchytre-

idee may be separated by the absence of biuncinate sete, while

representatives of the families Lumbrieulide and Tubificidæ

1 Colored oil drops are absent in Holosoma beddardi, Holosoma nıveum from

North America, and two species of Pleurophleps occurring in Ceylon and Cen-

tral America.

686 THE AMERICAN NATURALIST [Vor. XL

usually exceed 20 mm. in length, while the Naidide on the con-

trary are rarely more and usually much less than 15 mm. in length.

The form and position of the sete are the chief characters

relied upon for the separation of the genera and species. ‘These

may be long and hair-like (capilliform), short and straight (needle-

like), or S-shaped (sigmoid), and may terminate simply or in two

hooks (biuncinate). A slight enlargement (nodulus) is usually

present on all biuncinate sete. The accompanying diagrams

representing a typical Naid (Fig. 1) together with the different *

Fic. 1.— Typ nieal N AT 2,3 111 t4 3 4%. £

and species. The lowing abbreviations are used in this and subsequent

; br, brain;

biuncinate seta; dv, dorsal blood vessel; e, eye; n, nodulns; np, Ken

ium; ns, needle-like seta; o, esophagus; ov, Ovary; p, pharynx; pr,

prostomium; ps, palmate € Agr grapes tooth, biuncinate seta; s, stom-

ach; sp, spermatheca; t, t ; te, fine teeth on capilliform seta in Pristina;

tc, mieu teeth on seat seta in ine genus Vejdovskyella; 2 tentac-

ular process; tp, tubular respiratory pr ocess; tv, transverse blood vessel; v,

caedes bundle of sete; vn, Meri nervous system; vv, ventral de vessel;

1-7, seven anterior segmen

forms of sete (Fig. 2) will prove of assistance in making clear the

characters used in the synoptic table which has been slightly

modified from Michaelsen (:00) who in turn adopted a large pro-

portion of it from Vejdovsky (84). The reproductive organs have

not been sufficiently studied to admit of a final conclusion con-

cerning their typical arrangement. This includes all genera known

up to the present time, those occurring in North America being

No. 478] OHIO NAIDIDE 687

printed in heavier type. Since the publication of this monograph

by Michaelsen one new genus (Hemonais) has been founded

by Bretscher, while Michaelsen (:03) has proposed the name

Vejdovskyella for Bohemilla, the latter being preoccupied.

FAMILY NAIDIDAE

1791. Nais [ex Ord. Mollusea, e Class. Vermes] (part) Gmelin,

Syst. Nat., vol. 6, p. 312

1895 N aidomorpha le Group Microdrili) Beddard, Monogr. Olig., p.

1900. Naidide Michaelsen, Monogr. Olig., Das Tierreich, Lief. 10,

1903. Naidide Michaelsen, Die geogr. Verbreit. d. Olig., p. 41.

1905. Naidide Michaelsen, “Zur Kenntnis d. Naididen,” Zoölogica,

vol. 18, p. 350.

Setæ aggregated together in 2 or 4 bundles on a segment. Dor-

sal bundles composed of capilliform,

short needle-like, or sigmoid (the

latter biuncinate) setæ; dorsal bun-

dles often absent; ventral bundles

composed of sigmoid biuncinate

sete. Dissepiments well developed.

Brain, commissure, and ventral

nerve-cord well developed, distinct

from the hypodermis. Esophagus

without muscular stomach. Ne-

phridia large, occasionally entirely

absent. Testes in segment 5 or 7

(rarely in segments 8 and 9). Ovaries A 2— Pinca m Br

in segments 6 and 7 (rarely in seg- inne wn Fi. 1

ment 10). Spermatheca in segment

5 or 7. Reproduction normally asexual by budding. Length

of specimens varies from 1 to 50 mm.; usually from 2 to 10 mm.

Usually in fresh water, rarely in saline waters. One (Amphi-

cheta) marine. Cosmopolitan; fifteen genera.

688 THE AMERICAN NATURALIST [Vor. XL

Synoptic Table jor Separation of Described Genera

(Genera occurring in North America printed in heavy type)

Al. Capilliform setze absen

B'. Dorsal bundles of = absent.

Ct, Ventral bundles of setz on all segments beginning with the

second. Third segment not longer than visis ae 8

mardella.

C? Ventral bundles of setze absent on jeu 3-5. naar 3

extremely lon Chetogaster.

B?. 2 dorsal and 2 DN handles T siti ona Mit.

Ct, Segment 3 much longer than remaining segments. Length

(of described species) not exceeding 2mm. . Amphicheta.

C?. Segment 3 not longer than remaining segments. Length (of

described species) equal to or exceeding 5 mm.

D'. All sete of dorsal bundle biuncinate . . . . Paranais.

D?. Some of the setae of dorsal bundle not biuneinate Ophidonais.

A?. Capilliform setze present in the dorsal bundle.

B'. Dorsal bundle of setze beginning on segment 2, 5, or 6.

C, Dorsal bundle of setze beginning on segment 5 or 6.

D!. Posterior end developed into a tubular respiratory process

containing paired gills. Usually NO in tubes ag of

plant fragments, ete. . . Dero.

D?. Posterior end without rétitklory RER,

E!. Capilliform setze of dorsal bundle with a series of prominent

teeth. Dorsal bundle beginning on segment 5

Vejdovskyella.*

E^ Capilliformsete without teeth. Dorsal bundle beginning

on segment 6.

F'. Length of capilliform sete equal to at least twice the

diameter of the body.

G!. Capilliform setz on all en beginning with 6.

Prostomium rounded . . Macrochetina.

G?. Capilliform setze hr on one (6) or a few (6, 7, 8)

segments.

H'. Capilliform set: on segments 6, 7, and 8. Pro-

stomium developed into a tentacular process

Ripistes.

H?. Capilliform sete only on segment 6. Prostomium

not developed into a tentacular process. Slavina

F^. Length of capilliform setze shorter or rarely longer han

diameter of body.

! For Bohemilla, ende used as the generic name for a group of Trilo-

bites by Barrande, (Michaelsen. : 03).

No. 478] OHIO NAIDIDE 689

G!. Prostomium developed into a tentacular process

G?. Prostomium rounded .

C. Dorsal bundle of setze beginning on sae 2.

D'. Anterior capilliform sete partly covered by filamentous gills

Branchiodrilus.

D*. No filamentous gills present.

E'. Dorsal bundle usually composed entirely of capilliform

setze. Prostomium seran: into a long tentacular pro-

^ Pristina.

cess

E?. Doteal: pamili bonibusel in past of TENER or of short

needle-like sete. Prostomium rounded or with a short

tentacular process .

B*. Dorsal bundle of setze REN on BER: 12-20 Hemonais.

Genus CHAETOGASTER K. Baer, 1827

Prostomium rudimentary, coalesced with segment 1; 2 ventral

bundles of set on a segment, these absent on segments 1 and 3-5.

Sete uncinate. Pharynx large and wide. Esophagus small, not

longer than pharynx; 1 pair of transverse vessels connects the

dorsal and the ventral vessels. Longitudinal commissures of

ventral nerve-cord more or less distinct in anterior part of body.

Testes in segment 5, ovaries in segment 6, spermathece in seg-

ment 5.

In fresh water, free-living or parasitic on fresh-water snails.

Middle and south Europe, North America.

Five species are recognized by Michaelsen and to these must

be added C. pellucidus. Three species of Cheetogaster (C. dia-

strophus, C. diaphanus, and C. limnei) have been reported from

North America, while Leidy (52), described C. gulosus, so incom-

pletely, however, that it cannot be recognized, although undoubt-

edly referable to the genus Cheetogaster.

The following table will serve to separate all the species known

at the present time: —

Al, Prostomium distinct, usually with a pore on anterior margin

C. diastrophus.

(Europe, N. America.)

A*. Prostomium indistinct.

B!. Length of individuals not exceeding 5 mm.

C!. Esophagus as long as pharynx.

690 THE AMERICAN NATURALIST [Vor. XL

D!. Blood vessels of pharyngeal region well developed C. langt.

(Europe, N. America.)

D*. Blood vessels of Aide one region absent or only slightly

developed . . . C.crystallinus.

(Europe.)

D!. Ventral setze 8 to 12 in bundle, 1st EEE NR, dilation

of intestine covered with anastomosing network of blood

ved 4 0 9 3 90 342 «°C. Iimnat.

(Eur rope, N. America.)

D’. Ventral sete 6-7 in bundle, 1st postesophageal dilation of

intestine surrounded by 12 or more pairs of non-anastomosing

transverse blood vessels . . . . . . . C. pellucidus.

(N. America.)

B*. Length of individuals 10-15 mm. . . . . . C.diaphanus.

Chetogaster langi Bretscher

C. langi Bretscher, Rev. Suisse Zoöl., vol. 3, p. 512, fig. 1, 1896; Michael-

sen, Das Tierreich, Oligochaeta, Berlin, p. 21, 1900

Living specimens transparent. Prostomium blunt, indistinct.

Set unequally bifid at distal end, 4 in a bundle.

Esophagus long. Ventral ganglia glandular in

form. Circulatory system with normal develop-

ment in the pharyngeal region, 1 pair of trans-

verse vessels (not developed as “‘hearts’’) in

esophageal segment. Length 1-2 mm.

Between filaments of alge in swampy places,

ete.

One specimen (Fig. 3) referable to this species

was obtained early in July. There were several

minor characteristics not wholly in agreement with

the description of C. langi, but in the absence of

more material it must be placed here.

Fic. 3.— Cheto- Chaetogaster pellucidus n. sp.

gasterlangi Bret-

—— Vene P. Transparent. Prostomium indistinct. Eyes

see Fig. 1. absent. Dorsal sete absent, ventral sete 6-7

in a bundle, biuncinate, with teeth unequal.

Esophagus short, postesophageal dilation (first stomach) sur-

No. 478] OHIO NAIDIDE 691

rounded by 12 or more pairs of non-anastomosing transverse

blood vessels. Length 1.5 mm. Number of segments in an indi-

vidual from 9 to 11. Budding in all specimens observed.

Sandusky Bay, Lake Erie.

A considerable number of specimens of this small Chietogaster

were observed in cultures of aquatic plants during July and Au-

gust, and a number were stained and mounted and are now in the

rai

Fic. 4.— togaster A. Dorsal aspect of budding individual (x25).

B. 1s tered aspect (x25). ^ itid bundle of setze (x250). istal por-

tion of a single biun ee seta ne form of distal and proximal tooth

(x1000). For abbreviations see F

collection of the Museum at Kenyon College. All found were

free living, while C. limnei, to which it is most closely allied, nor-

mally occurs on or in fresh-water snails. It is possible, however,

that they may have left their host as the age of the culture in-

creased. No snails were observed in the jar.

692 THE AMERICAN NATURALIST [Vor. XL

Furthermore, Vejdovsky ('84) figures the first postesophageal

dilation of C. limnei as being covered with an anastomosing net-

work of blood vessels, while in C. pellucidus they are plainly non-

anastomosing.

Genus Dero Oken, 1815

Prostomium rounded, eyes absent. Sete in four bundles on

a segment. Ventral sete uncinate, those of the segments 2 to 5

longer than the rest; dorsal bundle usually beginning on the 6th

rarely on the 5th segment, composed of a capilliform and one or

two needle-like setze with variously formed distal ends. Posterior

end developed into branchial filaments. Intestine with stomach.

Blood red. Nephridia paired from 6th segment. ‘Testes in 5th,

ovaries in 6th, spermathece in 5th segments.

Fresh water. Europe, North America, Antilles, tropical East

Africa, Tonkin, Philippines; fifteen species.

Four species of Dero have been reported from North America:

D. obtusa, D. limosa, D. vaga, and D. furcata.

Dero vaga (Leidy)

Aulophorus vagus Leidy, Amer. Nat., vol. 14, p. 423, figs. 3, 4, 1880;

Reighard, Proc. Amer. Acad., vol. 20, p. 88, pl. 1, figs. 1-10; pl. 2, figs.

11-20; pl. 3, figs. 21-31, 1885.

Dero vaga L. Vaillant, Hist. Nat. Annel., vol. 3, p. 383, 1890; Stieren,

‚Sitzb. Ges. Dorpat, vol. 10, p. 107, 1893.

D. furcata Bousfield (part), Journ. Linn. Soc. London, vol. 20, p.

105, 1887.

D. vaga Michaelsen, Das Tierreich, Oligocheta, p. 29, 1900.

Prostomium rounded. Ventral bundle of segments 2 to 5 with

8 to 14 long slightly curved, biuncinate sete, with upper some-

what longer than the lower tooth. Ventral bundles of remaining

segments with 4 to 7 shorter, more curved, biuncinate sete with

the upper shorter than the lower tooth. Dorsal bundle of sete

beginning on 6th segment; composed of 1 to 3 capilliform and 1

to 3 palmate setze.

Posterior end with rudimentary branchia and two long finger-

No. 478] | OHIO NAIDIDE 693

like processes. ‘Three pairs of hearts in segments 8, 9, and 10.

Brain wider than long. Length 8 mm. or more; number of seg-

ments in an individual 24 to 35.

In slime of ditches, etc., among fresh-water plants. Massachu-

setts (Cambridge), Pennsyl-

vania (Philadelphia), Illi-

nois, Ohio (Cedar Point),

and Trinidad, West Indies.

This species was extreme-

ly common at Cedar Point,

particularly among cultures

containing Riccia fluitans,

the thallus of which together

with statoblasts of Bryozoa,

etc., it uses in the building

of a protective tube by

means of a viscid secretion

from the body. When walk-

ing around with its tube it

bears a striking resemblance

to a minute caddis-fly larva.

Genus StyLarıa Lamarck,

1816

—

Prostomium developed

into a tentacular process.

Ventral bundles composed

of biuncinate sete; dorsal

bundle composed of capilli-

form sete, beginning on 6th

segment. Testes in 5th,

ovaries in 6th, spermathece

in 5th segment.

Fresh water, Burope, 5. s- puo mapi Ludy. A. Dormi aspect

North America; one species. (x25). B. Lateral aspect, first six —

(x25). C. Dorsal gore of setze (x250)

6th segment (x 250).

EINER

Stylaria lacustris (Linné) For abbreviations see Tei

Nereis lacustris Linné, Syst.

Nat., ed. 10; p. 654, 1758; ed. 12, vol. 2, p. 1085, 1767.

694 THE AMERICAN NATURALIST [Vor. XL

Stylaria lacustris Johnston, Cat. Brit. Non-paras. Worms, p. 70, 1865;

N Syst. Morphol. Olig., p. 30, pl. 3, fig. 27; pl. 4, figs. 1-24, 26-

31,

ve ais ig Beddard, Monogr. Olig., p. 284, 1895; Michaelsen, Das

Tierreich, Oligocheta, p. 33, 1900

S. paludosa, S. fossularis Léidy; Proc. Acad. Nat. Sci. Phila., vol. 5,

pp. 286, 287, 1852.

Y A D ©

Fic. f lacustris (Linné). A. Dorsal aspect (x25). B. Lateral aspect,

t 6 segments (x25). c. Dorsal bundle of sete of 6th segment (x250).

» Ventral bundle of sete, 4th segment (x250). For abbreviations see Fig. 1.

No. 478] OHIO NAIDIDE 695

S. phyladelphiana, p scotica Czerniavsky, Bull. Soc. Imp. Nat. Moscou,

vol. 55, no. 4, p. 309,

Prostomium developed into a long tentacular process. Eyes

usually present. Distal teeth of ventral setæ unequal. Dorsal

setæ capilliform with 1 long and 1 to 2 short in each bundle. All

long setæ of each bundle approximately of the same length. Clitel-

lum in sexually mature forms on segment 6. Male pores on 6th

segment. Sperm duct in 5th, spermathecæ in 5th segment. Length

10 to 15 mm. Number of segments about 25.

Europe, North America (Pennsylvania, Ohio, Illinois).

A large number of specimens were observed which must at

present be referred to this species. Michaelsen notes the length

of N. lacustris as varying between 10 and 15 mm., while the length

of those found at Cedar Point was always from 4 to 5mm. The

teeth of the ventral setæ are also considerably shorter and more

obtuse than illustrated in the figures of Vedjovsky (84), Tauber,

and others. Furthermore, the length of the tentacular proc-

ess in those forms observed, did not exceed the length of the

long capilliform setæ while Müller (1774) notes the length of the

tentacular process as equivalent to ten segments of the body. The

synonymy of S. lacustris is in a confused condition, and it is possi-

ble that careful study will establish one or more new species in the

genus.

The imperfect descriptions given by Leidy (52b) to the species

described by him as S. paludosa and S. fossularis, will not per-

mit their separation from S. lacustris.

Genus Nats Müller, 1774

Prostomium rounded. Ventral bundle with biuncinate sete.

Dorsal bundle beginning on the 6th segment with capilliform

and variously pointed short sete. Testes in 5th, ovaries in 6th,

spermathece in 5th segments (in species where sex organs have

been observed). -

In fresh water. Europe, North America, South America, and

East India; ten species.

The genus Nais furnishes one of the most difficult problems

for the systematist attempting to define the limits of species among

696 THE AMERICAN NATURALIST [Vor. XL

the Naidide. The following table, however, embodies the results

of systematic work so far as they are known and comprises all

species described up to the present time.

A!, Set: of ventral bundle of segments 8 to 10 neither thicker than those

of other segments nor modified by possessing blunt tips with rudi-

mentary lower tooth.

B'. Eyes present.

C. Ventral setze of segments 2 to 5 much longer than those of suc-

ceeding segments. Dorsal setz capilliform, 4 to 8 in bundle

N. obtusa.

(Europe, S. Siberia.)

C^. Ventral setz of segments 2 to 5 not decidedly longer than those

of succeeding segments.

D'. Transverse blood vessels simple.

E!. Ventral sete of segments 2 to 5 unequally bifid at tip.

Length 1 to 1.5 mm. . N. elinguis.

(Eur urope, N. RER S. America.)

E’. Ventral setz of segments 2 to 5 equally bifid at tip.

F'. Number of segments in an individual approximately 10

(9 to 10), 6 to 8 ventral setæ in a bundle. Length of

specimen 1.5.mm. . . . eo. + N, parvula.

i (N. America.)

F’. Number of segments in an individual usually 20 (18 to

22), 4 ventral setæ in a bundle. Length of specimens:

at least 2 mm. ;

G'. Dorsal bundles composed of 1 long capilliform and 2

short needle-like setz. Eyes dumbbell-like in form

N. tortuosa..

(N. America.):

G^. Dorsal bundle composed of 1 long capilliform and 1

short biuncinate seta. Eyes oval, not dumbbell-like:

in form. Length 3.5 mm. . . . . N. parviseta.

(N. America.)

D’. Transverse blood vessels of erroen 2 to 5 forked. Dorsal

bundle with biuncinate sete. — . N. heterocheta.

(England.)

B*. Eyes absent.

C'. Proximal tooth of dorsal biuneinate setze not longer than the

distal tooth.

D'. Ventral bundle composed of 3 to 4 set. Length of indi-

viduals 3 to 3.5 mm. Colorless . N. tenuidentis.

D’. Ventral bundle EOE of 6 to 8 nd. Length 6 to 8 mm.

Color reddish . . N., josina..

g ele N. America.)

No. 478] OHIO NAIDIDE | 697

C. Proximal tooth of dorsal biuncinate setze twice the length and

twice the thickness of the distal tooth . . N. paraguayensis.

(S. America.)

A’. Setæ of ventral bundle of segments 8 to 10 much thicker than those

of other segments, 1 to 2 in number, er blunt, an tooth

FROBMEBUEE 2 o SUR 3 . bretscheri.

(Europe.)

D C

Fic. 7.— Nais parvula n. sp. A. Dorsal aspect (x50). B. Lateral aspect, first six

epar (x50). C. Dorsal bundle of sete of 6th segment (x250). D. Ven-

ral bundle of sete, 6th segment (x250). For abbreviations see Fig. 1

Nais parvula n. sp.

Prostomium blunt, rounded. Eyes present. Digestive tract

not differentiated into esophagus and stomach. Dorsal bundle

beginning on segment 6, composed of 1 capilliform, subequal to

diameter of body, and 2 short biuncinate setze. Ventral bundle

consisting of 6 to 7 biuncinate sete with teeth equal. Length 1.2

mm. Number of segments in an individual 9 to 10.

Cedar Point, Sandusky, Ohio.

Several examples of this extremely small Nais were found in

the slime accumulating at the bottom of jars containing roots of

various aquatic plants obtained from Sandusky Bay. It is chiefly

698 THE AMERICAN NATURALIST [Vor. XL

remarkable by reason of its small size, and the limited number of

segments composing the body. At first it seemed probable that

it was an immature form but evidence to the contrary was given

by budding in several specimens.

tss N

3; |

Va D | C

Fic. 8.— Nais tortuosa n. sp

" . . 1 + £ V8 + civ

segments (x50). C. Dorsal bundle of sete (x250). D. Ventral bundle of

sete, 2d segment (x250). For abbrevi ee Fig. 1.

Nais tortuosa n. sp.

Prostomium blunt, rounded. Eyes ‘present slightly dumbbell-

shaped. Digestive tract not differentiated into esophagus nor

stomach. Dorsal bundle beginning on 6th segment, composed of 1

long capilliform (180 x) and 2 short (50 x) needle-like setze. Ven-

No. 478] OHIO NAIDIDE 699

tral bundle consisting of 4 biuncinate sete (110 x) with subequal

teeth. Length 2.2 mm. Number of segments in an individual 18.

Cedar Point, Sandusky, Ohio.

Two specimens belonging to this species were noted. Budding

was not observed. Several Peritrichous ciliates (Rhabdostyla sp.,

length 50 », diameter 19 x») were observed fixed to the anterior

end of one of the individuals, the peduncle being less than 2 « in

_ length.

Nais parviseta n. sp.

Prostomium narrow, slightly acute. Eyes present, round or

. slightly oval. Digestive tract

differentiated into a distinct

pharynx which gradually

merges into an esophagus.

Stomach dilation scarcely per-

ceptible. Dorsal bundle be-

ginning on the 6th segment,

composed of 1 capilliform,

subequal to diameter of body,

and 1 short biuncinate seta,

possessing equally developed

teeth and an indistinet nodu-

lus. Ventral bundle composed

of 3 to 4 biuncinate sete, with

lower tooth considerably

larger than the upper tooth.

Length 3.5 mm. Number of

segments in an individual 19

D C

: , an Fig. 9.— Nais parviseta n.sp. A. Dorsal

Cedar Point, Sandusky, aspect (x25). B. Lateral aspect, first six

Ohio segments (x25). C. rsal bundle of

: : s sete (x250). D. Ventral bundle of sete,

A very few specimens of this 4th segment (x250). For abbreviations

. i 1

form were observed. Budding

was noted in nearly all of the

individuals examined. The characteristic differentiation of the

teeth on the ventral setæ appears to be of considerable specific

importance.

700 THE AMERICAN NATURALIST [Vor. XL

Nais tenuidentis n. sp.

Prostomium blunt. Eyes absent. Digestive tract not differ-

entiated into esophagus or stomach, covered with many brownish

globules. Dorsal bundle be-

ginning on 6th segment, com-

posed of 1 capilliform, the

length (180 x) of which is

approximately one half the

diameter of the body, and 1

short (60 x») biuncinate seta

possessing equally developed

teeth and provided with a

nodulus. Ventral bundle con-

3 sisting of 4 (3 in several ante-

Hh rior bundles) deeply bifid sete,

d both teeth being exceedingly

F long and slender, the upper

à measuring 20 » and the lower

ii 14 » from the base of the cleft

E area. Length 3 to 3.5 mm.

E: | Number of segments in an

V2 A To individual approximately 20.

10.— Nais tenuidentis n. s Budding observed.

prie (X25). . Lateral koi first six .

segments (x25). C. Dorsal bundle of sete Cedar P oint, Sandusky f

of 7th segment (x250). D. Ventral bun- Ohio.

dle of setæ, 2d segment (x250). For A

abbreviations see Fig. 1. Only two specimens of N.

tenuidentis were found, bud-

ding occurring in each. The extremely long and slender teeth of

the ventral setze are a striking characteristic of this species.

—

Genus Pristina Ehrenberg, 1831

Prostomium usually developed into a tentacular process. Ven-

tral bundle composed of biuncinate sete. Dorsal bundle begin-

ning on the 2d segment, composed of capilliform sete. Testes in

7th, ovaries in 8th, spermathece in 7th segments (description of

sexual organs based on observation of one species, P. leidyi).

No. 478] OHIO NAIDIDE 701

In fresh water. Europe, North America, South America, and

Java; 6 species.

The species may be separated by the following table. While

it is possible that a careful study of P. equiseta, P. longiseta, and

P. flagellum, may show that those responsible for the descriptions

have overlooked the existence of the small teeth present in P.

leidyi and P. serpentina, it appears evident that the species are

distinet on other grounds.

Al, Sete of dorsal bundle smooth.

B*. Last segment not provided with finger-like processes.

C. Dorsal sete of 3d segment not decidedly longer than those of

other segments; length 7 to 8mm. . . . . P. aquiseta.

(Europe.)

C. Dorsal setze of 3d ER much Re than those of other

apnenbi v. us kx ou. u longeda:

Europe.)

B’. Last segment provided with 3 (2 lateral and 1 median) finger-like

processes projecting posteriorly . P. flagellum.

m. Be S. America.)

A’. Sete of dorsal bundle provided with numerous fine but distinct teeth.

B'. Capilliform setze of dorsal bundle approximately 35 «long. Those

of the 3d segment twice as long as the others . . P. leidyi.

(N. America, 8. America.)

B*. Capilliform setze of dorsal bundle approximately 300 «long. Those

of the 3d segment not longer than others.

C. Teeth of ventral setze Sasse Number of vague approxi-

mately 14. . . koe ‘ P. serpentina.

(N. America.)

C. Distal teeth of ventral setze € than proximal teeth. Num-

ber of segments 18 to 30 ^ pe o P. proboscidea.

(S. America.)

Pristina serpentina n. sp.

Prostomium developed into a long tentacular process, usually

0.2 to 0.3 mm. in length. Eyes absent. Digestive tract with

stomach in the anterior part of the 8th segment. Dorsal bundle

beginning on the 6th segment, composed of 2 long (300 x), 1 medium

(100 «) capilliform sete, and 2 to 6 short needle-like (30 x to 50 x)

sete. Ventral bundle composed of 5 to 6 biuncinate (60 to 80 x)

sete with subequal teeth. Length 2.2 mm. Number of segments

in an individual about 15.

702 THE AMERICAN NATURALIST [Vor. XL

Cedar Point, Sandusky, Ohio.

This species of Pristina (Fig. 11) was exceedingly abundant at

Cedar Point, and on first examination was apparently to be placed

near P. @quiseta Bourne. Closer examination, however, dem-

Fic. 11.— Pristina ad iens n. sp. Dorsal aspect (x50). B. Lateral cen

first six segments (x50). C. Pise bundle of sete of 7th —— (x250

D. Ventral apes of sete (x250). For abbreviations see Fig. 1

onstrated the existence of fine teeth on the setze of the dorsal bundle.

The difference in the form of the distal teeth of the ventral setze dis-

tinguishes it from P. proboseidea Beddard, now recognized by

Michaelsen (:05) as a valid species.

No. 478] OHIO NAIDIDE 703

Genus Narpium O. Schmidt, 1847

Prostomium either rounded, pointed, or developed into a short

tentacular process. Dorsal bundle beginning on the 2d segment,

. composed of capilliform, or needle-like, and biuncinate setze. Ven-

tral bundle composed of biuncinate set:e.

Fresh water. Middle Europe, East India, North America, and

South America; six species.

A'. Prostomium not developed into a tentacular process.

B'. Number of segments composing an individual usually 15 to 30

(32 to 40, N. luteum). Biuncinate setze in dorsal bundle.

C'. Prostomium rounded or pointed, species small, not exceeding

5 mm. in length.

D'. Number of segments in an individual 20, posterior part of

brain developed into 4 pronounced lobes . N. bilobatum.

(Europe.)

D’. Number of segments in an individual 15 to 16.

E'. Capilliform setz shorter than the diameter of the body.

Teeth of dorsal biuncinate setze approximate N. uniseta.

(Europe.)

E?. Capilliform sete longer than the diameter of the body.

Teeth of dorsal biuneinate setze remote . . N. osborni.

(N. America.)

C? Prostomium u en species e a ger d 15

mm. in length . N. luteum.

(Europe.)

B?. Number of segments in an individual 40 to 61, no biuncinate setze

in dorsal DORI u. in í ayi.

6. America.)

A?. Prostomium developed into a short tentacular process, length of

species approximating 5 mm N. breviseta.

(East India.)

Naidium osborni n. sp.

Prostomium moderately long, somewhat pointed. Eyes absent.

Digestive system differentiated into pharynx (segments 1 to 3),

esophagus (segments 4 to 7), and stomach (8th segment). Dorsal

bundle of setze beginning on the 2d segment, composed of 1 long

capilliform (145 &) and 1 short (50 x) seta, the latter biuncinate -

704 THE AMERICAN NATURALIST [Vor. XL

with subequal, remote teeth and an indistinct nodulus one third

the distance from the tip. Ventral bundle composed of 4 biun-

cinate setze with subequal teeth and a distinct nodulus midway

between base and tip. Length 1.6 mm. Number of segments

in an individual 15 to 16. Budding observed.

Cedar Point, Sandusky, Ohio.

Five species of Naidium have been described: three from cen-

tral Europe, one from the East Indies, and one from South

America; none, however, has

been noted in North America,

consequently the occurrence

of a distinct species in the

United States is of considera-

ble interest. A single individ-

ual was found in the sediment

of a bottle containing “reed

roots” obtained at Cedar

Point, Ohio, and received from

Professor Osborn, September

4, 1905.

Schmidt (1847) founded the

genus upon a single species,

N. luteum, occurring in Eu-

rope. Beddard (’95) main-

tained that this species should

» be incorporated in the genus

JA C Pristina inasmuch as Pristina

Fic. 12.— Naidium osbornin.sp. A. Dorsa breviseta described by Bourne

sone uo. B Taten eet oi tt (1891) nearly- bridged over

zur oan: , Digni Pude the gap formerly supposed to

ations see Fig. 1. . separate the two genera.

Michaelsen (:00) removed P.

breviseta to the genus Naidium which thus consisted of two spe-

cies, N. luteum and N. breviseta.

The characters which may be used for separating the two genera

consist of (1) the presence as a rule of biuncinate sete in the dorsal

bundle of Naidium, while such setze are absent in Pristina, and (2)

the development of the tentacular process of the prostomium which

No. 478] OHIO NAIDIDE 705

is either absent or extremely short in Naidium while in Pristina

it is long. ‘The absence of any tentacular process in N. osborni

suggests that until a species is found in which the process is well

developed and in which the dorsal bundles contain biuncinate

sette, the genera may be considered distinct. Further studies

may show other generic characters.

I take pleasure in dedicating this species to Professor Herbert

Osborn, Director of the Lake Laboratory, Sandusky, Ohio.

KENYON COLLEGE

GAMBIER, OHIO

BIBLIOGRAPHY

Only a few of the more important papers, particularly those referring

to North American Naididz, are noted.

Brpparp, F. E.

'95. A Monograph of the Order of Oligochzeta. Oxford.

BRETSCHER, K.

:00a. Mitteilungen ueber die euere der Pee. Rev,

Suisse Zoöl., vol. 8, pp. 1

BRETSCHER, K.

:00b. Siidschweizerische Oligocheten.

: Recheshhunaen vu die Oligochzeten der Schweiz, VII. Rev.

Suisse Zoöl., pp. 1

CRAGIN, F. W.

‚87. First Contributions to a Knowledge of the Lower Invertebrata

of Kansas. Bull. Washb. College Laboratory, vol. 2, no. 8, pp.

27-32.

Lery, J.

’50a, Description of New Genera of Vermes.

Philadelphia, pp. 124-126.

Lerpy, J.

’50b. Descriptions of some American Annelida Abranchiata. Journ.

Acad. Nat. Sci. Philadelphia, vol. 2, pp. 43-55

Proc. Acad. Nat. Sci. Phila-

Rev. Suisse Zoöl., vol. 8.

Proc. Acad. Nat. Sci.

Lety, J.

62a. Helminthological Contributions.

delphia, vol. 5, pp. 226-227.

706 THE AMERICAN NATURALIST [Vor. XL

Lemy, J.

'52b. Corrections and Additions to Former Papers on Helminthology.

Proc. Acad. Nat. Sci. Philadelphia, vol. 5, pp. 285-287.

Lewy, J.

'80. Notice of some Aquatic Worms of the Family Naides. Amer.

Nat., vol. 14, pp. 421-425.

MICHAELSEN, W.

:00. Oligochzta. Das Tierreich, Lief. 10. Berlin.

MICHAELSEN, W.

- Die geographische Verbreitung der Oligochzten. Berlin.

MICHAELSEN, W.

:05. Zur Kenntnis der Naididen. Anhang Untersuchungen ueber

die Susswasser-mikrofauna Paraguays. Zoölogica, vol. 44, pp.

350-361

Minor.

'63. Upon Natural and Artificial Selection in some Chzetopod Anne-

lida. Amer. Journ. Sei., ser. 2, vol. 35, p. 35-43.

REIGHARD, J.

On the Anatomy and Histology of Aulophorus vagus. Proc.

Amer. Acad. Arts and Sei., vol. 20, pp. 88-106.

SMITH, FRANK.

'96. Notes of Species of North American Oligocheta. Bull. Ill. State

Lab. Nat. Hist., vol. 4, pp. 396-411.

PAM, FRANK.

Notes on Species of North American Oligocheta. Bull. Ill.

State Lab. Nat. Hist., vol. 5, pp. 441-458.

Vespovsky, F.

'8&. System und Morphologie der Oligoehzeten. Prag.

MECHANISM OF THE ODONTOPHORAL APPARATUS.

IN SYCOTYPUS CANALICULATUS

J. Coo HERRICK

INTRODUCTION

Tuis paper gives the results of some four or five weeks spent in

dissecting and experimenting on the odontophoral apparatus in

the large familiar whelk or winkle, Sycotypus canaliculatus (Linn.).!

The work was done at the Marine Laboratory at Wood’s Hole,

Mass., during the summer of 1905. I desire to express here my

thanks to the direction of the laboratory for the material furnished

and privileges extended, especially to Dr. G. A. Drew to whom I

am indebted for advice and encouragement.

The object of the paper is to show the modus operandi of the

whole odontophoral mechanism as found in the form selected, and

also, incidentally to describe the nervous supply of the muscles

that control the mechanism. To this end the anatomy of the parts

has to be described in some detail, but it is hoped that the figures

which accompany the text may serve to give some substance to

the descriptions.

Sycotypus because of its large size offers excellent material for

such a study. The whole apparatus can be studied with the

naked eye, no dissecting lens being necessary except for examin-

ing the teeth. Besides, since this animal is a great pest to the

oysterman and clam digger on account of its depredations upon

the beds, it is of some interest — aside from the purely scientific —

to know more intimately how this gastropod accomplishes its

destructive work of boring through the shells of oysters and clams,

and rasping out their soft contents by means of its file-like-

" tongue."

! Synonymy (Verrill): Murex, Pyrula, Busycon, Fulgur.

707

708 THE AMERICAN NATURALIST [Vor. XL

METHOD

The method followed was that of gross dissection, combined

with that of stimulation by the induced electric current, of the

muscles and nerves concerned. ‘The animals were freed from

their shells by means of a hatchet, chipping away the shell along

the line of the canal, and finally twisting the animal out; and then

left for twelve hours or more in a mixture of waste alcohol and

turpentine. This treatment! causes the animal to put forth its

proboscis usually in full extension, and does not really kill it,

though, of course, causing deep narcosis. In this condition the

various muscles (or nerves) can be dissected out, stimulated, and

their action studied.

HISTORICAL

Huxley, in 1853, was the first to study the mechanism of the

buccal or odontophoral apparatus in a number of forms. He

observed it in action in the transparent heteropod, Firoloides,

and from what he saw was led to believe that Cuvier had failed to

grasp the mode of operation of the same apparatus which he had

described in Buccinum. Cuvier, to quote Huxley, “considered

the tongue-plate [radula] to be passive, and that its movements

depended upon the protraction, retraction, divergence, or approx-

imation of the cartilages.” According to Huxley, Middendorff

also, in his elaborate monograph upon Chiton, in which he gives

a very careful and detailed description of the buccal apparatus,

“fails in rendering its action clear.” The radula “acts as a sort

of elastic file pushed from behind [!] by a special muscle, the

‘curvator radulæ, and supported and steadied by the ‘folliculi

motores’ [buccal cartilages]." `

It will be well to quote in full Huxley’s own explanation of the

mode of operation of the apparatus, as I deem it the correct one,

though, as we shall see, denied subsequently by his pupil, Professor

Geddes and others: “I have already described the manner in which

the apparatus may be seen working in Firoloides and Atlanta and

I propose now to demonstrate that from the anatomical arrange-

* Due to Mr. G. M. Gray, Curator, I believe.

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 709

ments the ‘tongue’ has the same chainsaw-like mode of operation

throughout the Cephalopoda and Gasteropoda. Perhaps Patella

may be taken as the most convenient illustration, since the organ

is here very large [however, not nearly so large as in Sycotypus],

and its parts are distinct and well developed." After describing

the apparatus in Patella, he says: “It is clear that the action of the

intrinsic muscular bands (having the insertions described) must

be to cause the elastic plate [radular membrane], and with it the

“dentigerous plate’ [radula], to traverse over the ends of the carti-

lages, just like a band over its pulley, the cartilages themselves

being entirely passive in the matter. The extrinsic bands, again,

must serve to protract the whole mass and thrust it more or less

firmly against the object to be acted upon.

“I have examined Buccinum, Fisurella, Doris, Aplysia, Bullsa,

Helix, Onchidium, Cyprza, Pteroceras, Sigaretus and Vermetus,

and in all I have found a structure essentially similar to that here

described ....

“ This pulley-like structure of the tongue appears to me to be

very characteristic of the portion of the molluscous type here

considered [cephalous], and indeed to be peculiar to it" (Huxley,

"593, p. 58, fl.).

Lacaze-Duthiers (56) in his study on Dentalium describes the

odontophoral apparatus fully and takes up the question of its

mechanism. He concludes (756, p. 258) that "the cartilage

executes movements and communicates them secondarily to the

dental apparatus."

In 1879, Geddes, at the suggestion of Huxley, took up the study

of the odontophoral apparatus again, but arrived at just the oppo-

site conclusion to that of the latter. He says in regard to Patella

that “a slight sliding of the radula over the apex of the cartilages "

may take place; but for Buceinum: “Little of that sliding move-

ment over the apex of the cartilages which we saw in Patella can

here take place, owing partly to the weakness and curvature in

two planes of the cartilages, partly to the sharpness of their apex,

eminently unfitting it for a pulley-block, partly to the slight fixed

flexure of the radula, and its wants of pliability, and largely also

to the attachment of the infraradular membrane to the sides of the

mouth all round, which thus fixes the radula very steadily over

710 THE AMERICAN NATURALIST [Vor. XL

the cartilages. Some little yielding may take place; but it must

be evident, from the above considerations, that the movements of

the radula are similar to, and dependent upon, that licking action

impressed upon the buccal cartilages in the way we have seen....

“Thus the explanation here put forward has something more in

common with that of Cuvier. . . .than with the later theory proposed

by Professor Huxley. ...

“In the transparent bodies of some Heteropoda, Prof. Huxley

describes a chain-saw movement; so, if the framework remains

quite stationary, I can only suggest that the sliding of the radula.

over its support, which we saw as a secondary factor in the Limpet,

though impossible in the Cuttlefish and highly improbable in the

Whelk, may in these animals have acquired greater importance.”

Tryon (’81) in his Manual of Conchology (continued by Pilsbry)

gives nothing as to the mechanism of the odontophoral apparatus.

Wegmann (’84) describes the odontophoral apparatus in Haliotis.

and as regards the mechanism says ('84, p. 304): —

"No muscle is inserted upon the radula properly speaking;

this organ is borne by the elastic membrane [radular membrane],

with which it forms one body in its movements. The latter slides

over the cartilages, drawn as it is by two pairs of protractor muscles.

and by numerous retractor bundles. Besides, the cartilages can

be brought together or separated, increase and diminish the space

between them. The elastic membrane is deeply influenced by

these displacements and its own movements are thus complicated." ’

Boutan ('86) in his paper on Fissurella gives a brief description

of the muscles of the odontophoral apparatus, but does not dwell

upon the mechanism except to emphasize the importance of the

blood sinuses in the proboscis. These during protrusion of the

proboseis become filled with blood and produce turgidity of the

organ, in fact, the protrusion is in part due to this turgid condition

of the proboscis.

Bouvier (87), while he gives a minute description of the nervous

system of Buccinum and of many other Prosobranchs in his

elaborate paper, does not describe the odontophoral apparatus at

all fully.

Gibson (’87) describes the odontophoral apparatus of Patella.

but has nothing to say upon the subject of its mechanism.

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 711

Loisel (792) describes the apparatus as found in Helix, and gives

a rather confused account of its action.

Oswald, in 1893, published quite a detailed account of the

"Rüsselapparat" of the Prosobranchs, dealing especially with the

apparatus as found in Buccinum undatum. He describes at length

the muscles that control the movement of the radula, as well as

those concerned with the protrusion and withdrawal of the pro-

boscis, and his descriptions are accompanied by a number of

text-figures, schemata, and two plates. He also considers the

mechanism of these parts. His observations for Buccinum

closely parallel my own for Sycotypus, with some exceptions,

and I find he suggested in a number of cases the very nomencla-

ture I had adopted on my own account; for all my own obser-

vations had been made before the literature of the subject became

accessible to me.

In regard to the rasping action of the radula, whether it is accom-

plished by the licking action of the cartilage or by active to and fro

motion over the odontophoral cartilage, Oswald has the following

to say (93, pp. 146-147): “The motion of the radula is brought

about by the contraction of its own muscles and at the same time

by the movement of the cartilage. By the contraction of the

approximators of the cartilage [rami] the anterior portions of the

cartilages are brought nearer together, the radula is raised up,

lying as it does over them, and, at the same time, pushed some-

what forward; the dorsal retractors relax, the ventral ones con-

tract and the radula slides, as Huxley suggests, like a band over

a pulley. The contraction of the approximators of the cartilage

having ceased, the anterior ends of the cartilage by virtue of their

elasticity separate, and at the same time the dorsal retractors pull

the radula back. The sliding of the radula over the tongue

cartilage in the manner of a band over a pulley is, it is true, very

limited (sehr beschrünkt), since the radula is fastened on both

sides by its sheath to the mouth cavity; that, however, such a

sliding motion does take place, has been made clear by my prepa-

rations, in which the radula was fixed in different stages of its

excursion."

In the main Oswald's account of Buccinum accords with what

I have observed for Sycotypus, but in Sycotypus, at least, the

712 THE AMERICAN NATURALIST [Vor. XL

motion of the radula over the cartilage as a band over a pulley is

in no way “sehr beschränkt,” for two to three centimeters of the

length of the ribbon play back and forth over the head of the

cartilage. One can easily convince oneself of the large excursions

of the radula by placing one's finger tip in the mouth of an animal

that has been placed in the alcohol-turpentine mixture, and that

is consequently in no pleasant mood.

While Oswald states he made some observations on the living

animal, he makes no reference to any detailed artificial stimulation

of the muscles or nerves, and his conclusions as to the mechanism

are, it seems, drawn to a considerable degree from the anatomy

of the parts.

Plate (93) gives a brief description of the odontophoral appara-

tus of Oncidium verruculatum, but does not dwell upon the mech-

anism, though since he speaks of retractors and protractors of

the radula, he probably accepts a sliding action of that organ.

Amaudrut (98) in a lengthy paper upon the anterior part of the

alimentary canal in gastropods makes a comparative study of the

odontophoral apparatus as found in this group of molluses. He,

however, does not describe that of Sycotypus. On page 145 of

his article he begins a historical review of the question of the mech-

anism of “le bulbe," and the radula, which continues for some

thirty pages. I refer anyone to them for a complete statement

of the views put forth by various observers.

He himself absolutely rejects Huxley's view of the sliding action

of the radula. He says ('98, pp. 137, ff., 147): “Every theory

aiming at explaining the mechanism of the radula must take into

account the facts which precede [certain anatomical relations, p.

84] and the remarks which follow:

“The radula being flexible and having to function as a rasp

must when in use always have a certain degree of tension. Now

the rasp being united to the elastic membrane [radular membrane]

its movements become subordinated to those of this membrane,

and since the muscles and cartilages are connected only with the

membrane and not with the rasp it is through the tension of the

membrane that the tension of the rasp is secured. But this ten-

sion can be produced upon the whole membrane only by the

simultaneous contraction of the muscles that act upon it, for

every movement of traction exerted upon one point only would

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 713

entail a sliding of the membrane —a thing which anatomical

examination has shown us as being impossible (Fig. 45, Pl. V) -

[the figure is for Helix pomatia, but his assertion is a general one,

see p. 147, and refers to Prosobranchs too], and which direct obser-.

vation has never established [?]. Further, a traction produced

upon one point only of the membrane would occasion in it not.

only a sliding motion but also the production of folds in it, and

then, whether the flexible radula should follow the contours of the

folded surface or whether it should pass beyond, in either case it

would be in an unfit state for playing its röle of rasp.”

It is clear therefore that Amaudrut regards as tensors what other

observers and I have considered as protractors and retractors of

the radula. So far as Sycotypus is concerned he is in error, for

by direct observation one can easily convince oneself of the sliding

motion of the radula in this large gastropod.

His explanation is as follows: “The important differences in

the general mechanism which exist between the Pulmonata and

the Rachiglossa, are that, with the latter when the flexors [pro-

tractors] of the cartilages contract, the summit of the tongue is

not only drawn forward, but the lateral teeth separate, and when

the tensors [of the radular membrane] contract in their turn, the

teeth execute the reverse movement, seize the prey and carry it to

the entrance of the cesophagus.”

Direct observation of the action of the radula seems to have

been confined, on Amaudrut’s part, exclusively to Helix. His

explanation of the mechanism for this form is doubtless correct,

but he has certainly gone too far when he makes the general asser-

tion that a sliding motion of the radula is impossible. On the

contrary it has been observed by Huxley and a number of other

observers, as we have seen above.

Simroth (:01) follows Amaudrut in his description of the mech-

anism of the odontophoral apparatus among the Prosobranchs.

Under the heading, “ Der Fressact” he says (:01, pp. 490-491):

“The act of eating is accomplished in general in this way: — The

bulb executes regular piston-strokes from behind forward and the

tip of the tongue simultaneous twisting movements downwards

and backwards extending to the entrance of the esophagus. In

the forward position the teeth of the tip of the tongue grasp the

mouthful from beneath, then it is drawn in, cut off by pressure

714 THE AMERICAN NATURALIST [Vor. XL

against the immovable jaw where such an organ occurs, and,

. without lingering at all in the bulb, pushed into the esophagus.

‘The radula suffers thereby no shifting of any sort (keinerlei Ver-

schiebung) upon its support.”

Pelseneer (: 06, p. 7) in his volume on the Mollusca in Lankester’s

Treatise, speaking of the odontophoral apparatus, has the following

remarks: “ Applied to these cartilaginous pieces the radula, by the

action of special muscles, executes backward and forward rasping

movements."

Again (:06, p. 89): “The radular ribbon is supported by a

system of paired cartilaginous pieces furnished with protractor

and retractor muscles the action of which causes the radula to

move to and fro and work like a rasp on the prey seized by the

animal." :

From this review it is evident that the mechanism of the radula

is conceived of in two very different ways by most of the observers

that have up to the present worked upon it: —

(1) The radula remains at rest relatively to its support (the

cartilage) and its rasping action is due to movements of its support.

(2) The radula moves relatively to its support, plays back and

forth over its support like a band over a pulley, and its rasping

action is due to its own proper motion.

I hope to show conclusively in what follows that the action of the

radula in Sycotypus is of the band-over-pulley type. I do not

desire to generalize from observations upon one form, and that an

isolated one, Sycotypus being found only “along the Atlantic

coast of North America from the south shore of Cape Cod, to the

Gulf of Mexico” (Grabau, this journal,- vol. 37, pp. 515-539).

However, from a study of the figures given by Geddes and others

for Buccinum, I cannot help thinking that a renewed study of this

animal under experimental conditions will reveal the fact that the

play of the radular ribbon is not altogether “very limited,” as

Oswald concedes.

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 715

DESCRIPTION OF ODONTOPHORAL APPARATUS

Since this apparatus is found in the proboscis of the animal,

it will be well to commence with this organ. As I intend to give the

nervous supply of the muscles de-

scribed, it is advisable to take up

the nervous ganglia after the pro-

boscis. Following the brief des-

cription of the ganglia, will be taken

up in order: the esophagus and

buccal mass; the buccal cartilage,

its retractor and protractor muscles;

the radula, its retractors and pro-

tractors; and finally the musculature

of the proboscis, and the mechanism

of its protraction and retraction.

Proboscis.— Many of the Proso-

branchs possess a long proboscis,

-eye sometimes longer than the rest of

hf. the animal. In Sycotypus this organ

is well developed, the fully extended

5^àd dure iE. proboscis being in a fair-sized speci-

Ventral view of the fully vigens, men three or fourinches long. The

peel Ma, Wad fold: moe proboscis when protruded emerge

from the head fold (Fig. 1, hf.) which

surrounds its base like a collar, there being a deep groove between

the two, formed by the invagination of the integument. The

anterior half of the organ is almost circular in section, and hard to

the touch, while the posterior half is more flattened and flabby.

At the end of the proboscis is located the triangular mouth —

bounded by thick and hard lips — the base of the triangle being

ventral. When retracted the proboscis is completely hidden from

view; it lies entirely within the head fold, which is drawn together

so as to hide the opening through which the proboscis is put forth.

The proboscis has a tough muscular wall, invested by integu-

ment which is closely adherent to the underlying muscular layers.

At the base of the proboscis is a cup of white muscular fibers

"MO,

716 . THE AMERICAN NATURALIST [Vor. XL

through which the esophagus passes and into which some of the

retractors of the proboscis (to be dealt with later) are inserted (Fig.

2, rpb.).

The proboscis is a hollow tube containing within it the esophagus.

and the large cylindrical mass, called the buccal mass.

Nervous Ganglia.— The ganglia lie below the base of the pro-

boscis (in its protruded state) in the deep part of the head fold

Fic. 2.— Sycotypus canaliculatus. Dissection from the dorsal aspect. Head fold

laid open dorsally and ventrally; foot split open; proboscis hangs down over

the foot. col., collar; f., foot, split open; hf., head fold; pb., proboscis; rpb.,

retractors of proboscis; s. siphon; t., tentacle; vm., visceral mass; 2, posi-

tion of ring muscle,

and surround the esophagus (Fig. 3, ng.). The ganglia comprise:

the buccal, two small spherical ganglia closely adherent to the

ventral surface of the esophagus and united by a commissure;

the two cerebral ganglia; the pleural ganglia; the crossed visceral

pair; and the large pedal ganglia. Their relations are presented

in the accompanying diagrammatic figure (Fig. 4).

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 717

Nerves arise from these ganglia and are distributed to various

parts of the body; but those that will be especially dealt with, here

are the ones that arise from the buccal and the cerebral ganglia.

Dissection from the ventral side (semidiagram-

hf., head fold; mo., mouth; m. cup, re ig.

s., siphon; sg., salivary gland; t., tentacle; vm., visceral mass

From each buccal ganglion arise two nerves, one stout (inner),

the other very slender (outer). From the cerebral ganglion arise

718 THE AMERICAN NATURALIST [Vor. XL

five or six anteriorly directed nerves, and one directed laterally

which passes out across the salivary gland into the tentacle to

supply that organ and the eye. The distribution of the forwardly

directed nerves we shall see later. As they pass forward they

anastomose more or less.

The buccal and cerebral ganglia of each side are connected by a

Fic. 4.— Sycotypus canaliculatus. Ventral view al dee ganglia biens surround the

esophagus (diagrammatic, from several d ons); the ventral

rà of dissec

side of the ring is in full line, the dorsal in ‘dotted line, er he outline of the

. com., buccal commissure;

bn., , buccal nerves; . com., cerebral commissure; en.

com., cerebro-pedal commissure; le., left cerebral ganglion; _ left pleural

ganglion; lp., a ren g^ wr lv., left Te dd p. com.

pleuro-pedal commissure; rb., right buce glion - t cerebral

ganglion; rp., sigh peda ural acer: rv., right

e; al g

l en: rpl., eg sr

visceral ganglion

very short commissure passing between the most median nerve

coming off from the cerebral and the buccal ganglia (Fig. 4).

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 719

EsoPHaGUs AND BuccaL Mass

As stated above, the esophagus

and the buccal mass lie within

the proboscis. Whereas the eso-

phagus is closely adherent to the

dorsal wall of the proboscis

(numerous muscle fibers passing

between the two), the buccal

mass lies free within the pro-

boscis, except at the anterior and

posterior ends where muscles are

inserted into the wall of the pro-

boscis (Fig. 5). At the anterior

end the buccal mass is also united

with the esophagus by a thin

membrane (Fig. 5, m.). Con-

sequently if the proboscis be split

open along the ventral surface,

the entire buccal mass may be

removed without in any way in-

juring the esophagus, except at

its commencement where it is

united to the buccal mass (Fig.

We thus have three tubes, one

of which (the proboscis) contains

the two others, the esophagus

being dorsal, and the buccal mass

ventral. In cross section they

would appear as shown in Fig.

Fic. 5.— ee canaliculatus.

alo

e wu P X

zcH RAS

-rH [|B rm

oe ae E]

C "LE pa

Y I

€.

-F --- npw.

s ME T

NW | UE

"A NS >

KIAL N:

Bey AVA

F cmm] IE N

Ventral view; the proboscis has been laid open

he mid-ventral line, and the buccal mass has been resected and turned

proboscis wall; rms., radular muscle;

tractor.

ull; oa. ' protractors of cartilage, cut across; pw.,

rs., radular sac; tpr., triangular pro-

720 THE AMERICAN NATURALIST [Vor. XL

ODONTOPHORAL (BUCCAL) CARTILAGE

The radula or dentated ribbon is essentially a thin flexible file

which is worked back and forth over the odontophoral cartilage.

bm.

Fic. 6. — Sycotypus canaliculatus.

Dorsal view; buccal cavity and

-* .*,

buccal mass; c., cartilage covered

by radular membrane; e., esopha-

gus; r., radula.

forward on the dorsal, or

rather posterior surface, of

the upturned head. Itis in

By the protraction or retraction of

this cartilage over which the radula

runs like a strap over a pulley, the

lingual file (or better, rasp) is either

brought forward into the mouth to

a position where, aided by the hard

lips, rasping can be effected, or (on

retraction) it can be carried back

out of the way.

The cartilage has two long ram?

that unite anteriorly to form a head

(Fig. 8), the entire length being from

five to six centimeters in a fair-sized

specimen. ‘The cartilage has some-

what the form of a toboggan that has

been split up along the running part

to near the upturned front; the front

has been turned in laterally, so that

its rim is no longer straight, as in

a toboggan, but horseshoe-shaped.

The rami are deeply grooved dor-

sally and the grooves are continued

Fie. 7.— Sycotypus canaliculatus.

Diagram to show relation of esoph-

agus and buccal mass. bm., buccal

mass; e., esophagus; pw., probos-

these grooves that the muscles retracting the ribbon run. The

ribbon itself passes over the rim of the head of the cartilage as

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 721

over a pulley (Fig. 8, rim). Since the rim is not straight but horse-

shoe-shaped, the ribbon is

folded together as it passes

back over the cartilage, and

unfolded as it passes forward;

otherwise the animal would

rasp its own tissues. As it is,

the lateral teeth (Fig. 13, lt.)

are turned in against each

other, so that as the lingual

ribbon passes back from the

head of the cartilage they are

thrown out of action. This is

a very important point in the

mechanism, and one which has

not been insisted upon. The

shape of the head of the carti-

‚lage is perfectly adapted for .

this folding and unfolding of

the ribbon as it plays back-

ward and forward.

The grooved surfaces of the

rami and head furnish a very

smooth running surface for the

retractor muscles and their

tendons.

A ramus in cross section is

moon-shaped. Muscles find a

place of attachment along the

lateral edge, but the median

edge is thin and free of muscle

insertions. A line of muscular

attachment runs along the con-

vex side of each ramus on the

median aspect. This line

Fig. 8.—

Sycolypus canaliculatus. Dorsal

view of odontophoral cartilage, stripped

ofits muscles; the grooved surfaces of deos

rami face somew - ME

me., median ramus; rim, the a

ley-like portion of oe head.

marks where a sheet of cross muscle fibers passes from one ramus

to the other binding them together.

ramus are also attached muscles.

To the posterior end of the

122 THE AMERICAN NATURALIST [Vor. XL

In Fig. 8, the rami of the cartilage are spread apart since the

muscles binding them together have been cut through. In the

Fic. 9.— Sycotypus canaliculatus. Dorsal view; the proboscis has been laid open in

its entire length; the esophagus has been resected and removed; the head-

fold ey been split open; the protractors of the cartilage are omitted. bm.,

bucca ; €. cartilage, ramus of; col., collar; dscf., dorsal sheet of cross

fibers; e. era nat g., groove root of vid retractor; hf., head fold; /at.,

emi root of great d med., _— oot of pm ic Span m. cup,

muscular ped pw., proboscis wall; uberes radular mbrane;

rnm., ring muscle of doe. rpb., ae of be ei TÉ, cuddiar sac; 8.

siphon: = ee cle.

SNS

BES

LES “Ee,

UR AS

—

x A

FTETTT

d --

Fie. 10.— As) canaliculatus entral view of ee muscles, the

proboscis and head fold having oe opened; t l carti

ilage has

inn twisted somewhat to the right (of the animal) so as to bring its protrac-

tors into prominence (those on the right side are omitted), and also to expose

hat are to be seen in the left half. bn., nerves from piz ccal gan-

glion; c., cartilage; cn., nerves from cerebral rpa con., convex root o

great retractor; e., u. g., groove T t of great ret tractor; m. cup,

ganglia; nt., narre to s éenidcie: - pre., protractors of cartilage; prr. (a, b,

e) protractors of radula; r., radula; rc. — of cartilage; rm., radular

membrane; t., wet tpr., triangular. protracto: of cart —— ect, ventral

protractors; 5, stout nerve mud bu ganglion which enters

t retractor; 6, slender nerve from buccal ganglion; 7, nerve that branches

off from 7 and — rotractors of radula and ventral sheet of cross fibers.

Fic. 11.— Sycotypus can l

—— e

aliculatus. Ventral view of odontophoral muscles, some of

hich have been cut through; the entire wall of the proboscis has been re

moved except that portion into which the protractors of the cartilage are

o| d

nse

muscles, the dorsal sheet of cross fibers having been cut through; all of the

muscles are drawn on the right of the figure only. cf., cross fibers uniting

radula; proboscis wall; r., Ta ula; rc., retractor of cartilage; Tm.

radular membrane; TMs., radular muscle; rs. radular sac; fpr. t lar

protractor of cartilage; vsef., ventral sheet of cross fibers.

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 725

natural state the rami are closely approximated for most of their

course, and form the doubly grooved roadway for the retractors

of the lingual ribbon.

RETRACTORS AND PROTRACTORS OF THE ODONTOPHORAL CAR-

TILAGE — THEIR NERVE SUPPLY

Retractors.— These are two flat muscles which arise from the

posterior extremities of the rami of the cartilage, and pass back

one on each side to mingle with the fibers of the muscle cup at the

base of the proboscis (Fig. 9, rc.). They serve to pull the cartilage

— the whole buccal mass in fact — backward.

Their nervous supply comes through the stout nerve from the

buccal ganglion (Fig. 10, 4).

Protractors.— The protractors of the cartilage are conspicuous

Fic. guine ypus canaliculatus. Radular sac, radular membrane, radula, and its

rotractors removed from the proboscis and e out. ogr., place of

oda of great retractor; un protractors of radula; r., radula; rm., radular

membrane; rs., radular

narrow muscle bands (ten to twelve or more in number) that arise

from the lateral edges of the rami and pass forward to be inserted

into the ventral wall of the proboscis along two parallel lines,

(Figs. 10, 11, pre.). Besides these bands there is also a pair of

protractors that lie on either side of the buccal mass at its anterior

end (Figs. 10, 11, tpr.). Each is more or less triangular in shape,

the apex and dorsal edge lying along, and inserted into the lateral

edge of the cartilage ramus, and the base being inserted into the

radular membrane, and into the muscular wall of the buccal cavity

laterally and dorsally. The ventral edges of the two triangular

protractors are united by cross fibers, which serve to keep the

underlying muscles (protractors of the radula) in place = H,

cj.)

726 THE AMERICAN NATURALIST [Vor. XL

All these muscles pull the cartilage forward in the proboscis,

and it is by means of them that the dentate ribbon, which passes.

over the rim of the head of the cartilage, is brought forward into

position for rasping.

Their nervous supply comes through one of the nerves of the

cerebral ganglion. The nerve on each side runs along beneath

the protractors near their origin, sending branches to each, and

ends forward in the triangular protractor (Fig. 10, 7).

RADULA (LINGUAL OR DENTATE RIBBON)

The radula is a dentate ribbon which is adherent to the mem-

brane — radular membrane (subradular membrane) — that lines

Fie. 13.— Sycotypus canaliculatus. Radular teeth. mt., median tooth; lt., lateral

tooth.

the buccal cavity (Fig. 12, rm.). The membrane lies loose over

the head of the odontophoral cartilage, and passes back into what

is called the radular sac (Fig. 12, rs.), which contains the imma-

ture part of the ribbon, and anteriorly it is produced into a pouch

which lies on the ventral side of the anterior part of the buccal

mass beneath the cross fibers that connect the ventral edges of

the triangular protractors already mentioned (Figs. 10, 11, rm.).

Laterally the membrane passes into the general lining of the buccal

cavity. The membrane on the floor of the buccal cavity is loose

enough to admit of the protraction of the head of the odontophoral

cartilage a centimeter beyond the mouth, i. e., in forced protraction,

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 727

not in the living animal. The looseness of the membrane thus

allows of the forward and backward play of the ribbon in rasping.

The muscles that are responsible for the rasping movements of the

ribbon are not attached to the ribbon directly, but to the membrane

to which the ribbon is adherent (the radular membrane). By

treatment with alcohol the ribbon is readily separated from its

membrane. ‘That part of the ribbon which is mature and in

use is from three to four cm. long, whereas the immature part

which is folded up within the radular sac, and which cannot be

drawn out over the rim of the cartilage head is some five cm. long.

It is to the radular sac that the large retractors of the ribbon

are attached, the protractors being attached to the ventral pouch

of the radular membrane (Fig. 12, prs., ogr.).

RETRACTORS AND PROTRACTORS OF RADULA; CERTAIN ACCEs-

SORY MUSCLES — THEIR NERVE SUPPLY

Retractors (together with Certain Accessory Muscles).— The

retractors of the lingual ribbon are, as above stated, inserted by

tendons into the radular sac. At the region of their insertion they

are fused so as to form practically one muscle, but posteriorly

four separate roots can be distinguished (Figs. 9, 11, 14): —

(1) Alarge median root (Figs. 9, 11, med.), separable into lateral

halves, passes back to be inserted on either side into the lateral

and ventral wall of the proboscis and into the muscular cup at the

base of the proboscis.

(2) Two large lateral roots (Figs. 9, 11, 14, lat.), which are

continuous anteriorly with the median, pass outward on either

side and are inserted by a half dozen bundles into the lateral wall

of the proboscis somewhat anteriorly to the insertion of the median

root. In passing out to the wall of the proboscis, this muscle

crosses over the posterior portion of the ramus of the odontophoral

cartilage, and hence serves to hold it in place (Fig. 9).

(3) A slender root passes back in the posterior part of the

groove on the dorsal surface of each ramus of the cartilage —

groove root (Figs. 9, 11, 14, g.). These roots are inserted at the

tips of the rami, and are continuous anteriorly with the lateral

roots.

728 THE AMERICAN NATURALIST [Vor. XL.

(4) Another slender root on each side passes back beneath

(ventral to) the corresponding ramus and is inserted at the end

of the ramus on the convex ven-

tral surface — convex root (Figs.

11, 14, con.).

Thus the larger part of the

retractor is inserted into the wall

of the proboscis, while the smaller

portion finds insertion on the car-

tilage frame.

As stated, these four roots unite

anteriorly to form what may be

called the great retractor of the

radula, which is inserted by one

ventral and two lateral tendons

into the radular sac (Fig. 14, ten.).

These tendons and their muscular

continuations run in the doubly

grooved roadway formed by the

grooved dorsal surfaces of the two

cartilage rami, these being close

cotypus canaliculatus.

Fic. 14. —

Ventral view y the great retractor

ver, is represented;

removed, the ramiin part only being

show i à

oot of great retractor; rc., re-

tractor " cartilage; rs., radular sac;

ten., tendons of origin of great re-

ractor.

together anteriorly, held so by

cross fibers that pass between

them.

One set of these cross fibers

forms what may be called the

ventral sheet of cross fibers, passing

from the convex ventral surface

of one ramus to that of the other

(Figs. 10, 11, vscf.). This sheet

extends from the beginning of the

rami back to about the place

where the dorsal sheet (see further) ends; the ventral sheet ends

somewhat anteriorly to the dorsal sheet. In describing the

odontophoral cartilage, it will be remembered that mention was

made of a line of muscular insertion along the ventral surface of

the ramus; this is the line for the insertion of the ventral sheet.

Covering the great retractor are two sets of muscles that call for

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 729

attention here, since their purpose is to keep the retractor true to

its grooved path. It should be stated in the first place that a con-

siderable portion of the radular sac projects free above the roots

of the retractor of the radula, and is continued posteriorly into a

rather long radular muscle that is inserted into the muscle cup at

the base of the proboscis (Fig. 11, rs.,

rms.). The more anterior part of the

radular sac has inserted into it laterally

and dorsally strands of muscle, some

of which pass forward to be inserted

into the outer edges of the rami of

the odontophoral cartilage; others pass

backward to the same edges, thus giv-

ing rise to a criss-crossing which serves

to keep the radular sac in position and

to prevent the great retractor leaving

its grooved pathway (Fig. 15).

Dorsal to this double set of muscle

strands, i. e., more superficial, lies

what may be called the dorsal sheet oj

cross fibers (Figs. 9, 11, dsef.), which

pass from the outer edge of one ramus

to the outer edge of the other, not, how- ue c tae

ever, along the entire length of the trate the criss-cross fibers of

ramus but to within two em. or so of Et b n ied

the end. This dorsal sheet covers the apart, the ventral sheet of cross

criss-cross strands and the anterior one side only of the criss-cross.

part of the radular sac, as well as the — $2 5 hen gy E ie

anterior portion of the great retractor, tamus s PAS: re ier

All that is seen of the great retractor, a

upon opening the proboscis along the |

mid-dorsal line and removing the esophagus, is the roots passing

from beneath the posterior edge of the dorsal sheet along with the

radular sac (Fig. 9).

The dorsal sheet of cross fibers thus serves to keep the rami

approximated, and to form a sheath for the radular sac and great

retractor, keeping the two in the proper place for motion along the

grooved roadway of the rami, therein sharing the function of the

730 THE AMERICAN NATURALIST [Vor. XL

criss-cross strands. Also, the two sheets of cross fibers, dorsal

and ventral, serve on contraction to give stifiness to the cartilage

frame as a whole and to prevent its buckling.

Nervous Supply of the Great Retractor.—'The great retractor

muscle is supplied from the stout nerves that leave the buccal

ganglia and run forward to penetrate the lateral halves of the

median root, and then to continue on to the other roots, and also

to the retractors of the cartilage (Fig. 10, 5).

Protractors.— The protractors of the lingual ribbon are six quite

distinet long slender muscles that are found on the ventral side

of the buccal mass and of the odontophoral cartilage. ‘There are

three on either side of the mid-line (Figs. 10, 11, prr., a, b, c).

pret b) prr.(c)

Fic. pes —8 en en Diagram to illustrate the position of the pro-

actors of t pon the cartilage ramus. c., coho ramus of; prr.

"pis Sici ue oe sacle: sh., connective tissue shea

‘The protractors arise from the membranous pouch in which the

anterior part of the ribbon is found, and extend quite or almost

straight backward.

(1) ‘The most ventral muscles are a pair that lie as two delicate

red bands along the mid-ventral line of the buccal mass, separated

by a white line (blood vessel) (Figs. 10, 11, prr., a). They arise

from the ventral surface of the membranous pouch, and pass

backward, adherent to the ventral sheet of cross fibers, to mingle

with the lateral halves of the median root of the great retractor of

the radula.

(2) ‘The pair lying more dorsal are the largest — about four

times the size of the first pair (Figs. 10, 11, prr., b). Each

arises from the dorsal surface of the membranous pouch and

passes back along the inner half of the ramus of the odontophoral

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 731

cartilage on its ventral side in a shallow groove. It is held in place

by a sheet of connective tissue that binds it against the ramus, but,

at the same time, allows it to slide freely back and forth along the

face of the ramus. Each muscle of the pair extends to very near

the tip of its ramus, and is there inserted laterally.

(3) ‘The last pair — much smaller than the second but larger

than the first pair — arise close to, and laterally from, the second

and pass parallel to the second along the outer half of the ramus

on its ventral surface to be inserted, a centimeter or so anteriorly

to the end of the ramus, into its outer edge (Figs. 10, 11, prr., c).

‘The muscles of this pair are, like those of the second pair, contained

within a connective-tissue sheath (Fig. 16).

The anterior parts of all these protractors are covered by the

cross fibers that pass between the two triangular cartilage pro-

tractors (Fig. 11, cf). These three remarkably long muscles

(they would make fine material for physiological experiments

upon molluscan muscle because of their length and regularity)

serve to pull the membranous pouch toward the base of the pro-

boscis, and consequently the lingual ribbon, which is adherent

to the inner surface of the dorsal wall of the pouch, out over the

head of the odontophoral cartilage. Their mass is extremely

small when compared with that of the great retractor, and this

is what one would naturally expect, since the rasping takes place

on the return pull. It is then that resistance is to be overcome,

and there is need for a large muscle, whereas in the forward motion

of the lingual ribbon very little power is required, since the teeth

of the ribbon have their “set” backward, and merely slip over

the surface to be rasped on the forward motion of the ribbon (Fig.

i: is very easy to demonstrate the rasping action of the dentate

ribbon on a recently narcotized specimen by alternately stimulating

the retractor and protractors, when the ribbon plays back and

forth very prettily. Of course, the same result is obtained by

alternately stimulating the proper nerves, as I have frequently

done. It might be well to mention the fact that the nerves of

Sycotypus are very slow in dying; they respond to a stimulus

(electrical) twenty-four hours and more after the animal has been

taken from the alcohol and turpentine mixture.

732 THE AMERICAN NATURALIST [Vor. XL

Nervous Supply.—The protractors of the ribbon are supplied

by nerves from the cerebral ganglia. 'l'he cords supplying them

branch off from the two (one on either side) which go to the pro-

tractors of the cartilage. Where one of the latter passes under

the first cartilage protractor the cord comes off and, piercing a

few of the protractors near their origin, passes on to the surface of

the lingual protractors that lie upon the ramus, and then continues

on to the ventral sheet of cross fibers, which it supplies, and on to

the first pair of slender lingual protractors (Fig. 10, 7). As will

be seen on consulting the figure, a sort of parallelogram anasto-

mosis is formed by this nerve upon the ventral surface of the buccal

mass in its lower third.

MUSCULATURE OF THE PROBOSCIS, NERVE SUPPLY

'The proboscis wall itself has a very well developed musculature.

This musculature is white in contrast to the very red muscles of

the buccal mass. The innermost layer of the proboscis wall is

one of longitudinal fibers, next comes a tolerably thick circular

layer, and beneath the integument is found another longitudinal

layer. The contraction of the longitudinal layers serves, of course,

to shorten the proboscis and to increase its diameter, whereas the

contraction of the circular layer would have the opposite effect.

The innermost longitudinal layer (at least) is supplied by nerve

cords that spring from the cerebral ganglion and pass forward

along the esophagus piercing in their course the muscle cup at the

base of the proboscis. One of these cords passes along outside

the line of insertion of the cartilage protractors to the end of the

proboscis, giving off branches to the wall of the proboscis as it

proceeds (Figs. 5, 10, 4). Another cord passes along parallel to

the one just mentioned, but inside the line of insertion of the pro-

tractors of the cartilage (Figs. 5, 10, 3). Still another, which

sometimes, at least, comes off as a branch of the second, passes

forward a little farther in toward the mid-line and is covered, like

the second in its anterior portion, by muscle strands that p

from the esophagus to the wall of the proboscis.

At the base of the proboscis is situated the muscle cup already

mentioned, and which is composed of transverse fibers that mingle

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 733

with the musculature of the proboscis wall (Fig. 5, m. cup). There

is also a ring musele entering into this muscle cup, which surrounds

the esophagus, but is free from it on the dorsal, though adherent

to it on the ventral side (Fig. 9, rnm.).

Below the cup are found very numerous white bundles of muscle

which arise, in part, from the cup, from the ring muscle, and also

from the proboscis wall with which they are continuous, and, in

part, from the fold of integument that surrounds the base of the

proboscis (Fig. 2, rpb.). These bundles pass backward to mingle

with the musculature of the integument that extends back from

the head fold to the columellar muscle; some bundles may mingle

with the fibers of the columellar muscle.

They serve on contraction to pull the whole proboscis back

within the head fold. They might be called the retractors of the

proboscis. These retractors are supplied from the cerebral

ganglia.

RETRACTION AND PROTRACTION OF THE PROBOSCIS.

Since there exists a distinct set of retractors at the base of the

proboscis, and since its wall has in part a musculature of longi-

tudinal fibers, it is not difficult to understand how retraction is

brought about. The basal retractors pull the whole proboscis

backward and the longitudinal fibers on contraction shorten it.

From dissections made upon specimens with retracted proboscis,

it seems that ordinarily there is no turning wrong side out of the

proboscis, the shortening of the proboscis itself, and the contraction

of the numerous retractors that run into the head fold, together with

the flexion of the proboscis, being sufficient to carry the organ

altogether back within the head fold. However, a certain amount

of doubling wrong side out may —in fact, does — take place under

artificial conditions. At the base of the proboscis, there is, as

stated, the muscle cup with its ring muscle; between this ring

muscle and the esophagus on the dorsal side there exists a space.

It is through this free space that the doubling takes place. Into

the anterior border of the ring muscle are inserted some of the

retractors of the proboscis, and on their contraction that part of

the proboscis above the ring begins to double back through the

734 THE AMERICAN NATURALIST [Vor. XL

space left between the ring muscle and the esophagus. On violent

stimulation (dissecting an animal that is not well narcotized) this

process may be so extensive as to double the whole proboscis

within the ring muscle, just as if one were to push in a finger of a

glove down to its base. In other words the proboscis may be

doubled in on itself down to the place marked x in Fig. 2

This *Einstülpung" must be brought about by the extensive

contraction of the retractors of the proboseis and their continua-

tion, the inner longitudinal muscular layer of the proboscis wall.

The proboscis cannot be turned wrong side out throughout its

entire length, as could a finger of a glove; for in the anterior end

the esophagus, which is closely bound to the dorsal wall of the

proboscis, and the buccal mass are united. Besides, the protractors

of the cartilage prevent such a complete doubling (Fig. 17).

TS.

Fia. ae — | canaliculatus. Side view of user turned wrong side out;

scles of buccal mass are filled in with fine lines; the musculature of the

ae and retractors of re are hes in outline

ass dorsal

age; musc

m retractors of proboscis; T3., radular Sac; vscf., aaie sheet of cross

fibers.

As to the protraction of the proboscis, I have only theory to

offer, as the experiments which I had contemplated upon this point

were never carried out. Of course, the relaxation of the longi-

tudinal fibers, as well as the contraction of the circular fibers of the

proboscis wall will account for its elongation, but how is the pro-

boscis forced out of the head fold? It may be that this is done by

means of a blood reservoir (sinus) within the head fold. If this

be filled with blood, and then the muscles of the head fold contract,

the effect would be to expel the proboscis. The region of the

head fold that is covered by the collar of the mantle is cavernous,

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 735

and if it acts as a blood sinus, there is little difficulty in explaining

how the proboscis is pushed out by hydrostatic pressure.

SUMMARY AND CONCLUSION

The results of the present investigation may be summed up as

follows: —

The odontophoral apparatus in Sycotypus is highly complex,

but admirably adapted to its function.

The mechanism of the radula, in Sycotypus at any rate, is

correctly termed, after Huxley, a chain saw, with the restriction

that the “sawing” occurs only on the return draw.

The buccal cartilage, besides forming a stiffening framework,

acts as a grooved pathway along which the radular sac and the

great retractor of the dental ribbon slide, the path being well

lubricated, probably by a mucous secretion. In Sycotypus the

cartilage is passive, so far as any licking action is concerned.

The buccal cartilage possesses its own muscles for protraction

and retraction, as well as certain muscles that bind its rami together

and at the same time form a sheath for the retractor of the radula.

The radula is protracted, 7. e., drawn forward, by six slender

muscles, four of which (two pairs) lie along the ventral side of the

rami of the buccal cartilage enclosed within connective-tissue

sheaths; the other pair lie along the mid-ventral line of the buccal

mass. The radula is retracted by a powerful muscle that arises

from its sac and is inserted by a number of roots into the proboscis

wall and upon the cartilage frame. This inequality of the muscles

is explained by the fact that the teeth of the tongue-file are inclined

backward, so that the rasping takes place on the return pull.

The retraction of the proboscis is accomplished through its own

longitudinal musculature and the continuation of this, the retractors

of the proboscis; there is usually little, if any, turning wrong

side out of the organ, though this may under certain conditions

take place. The protraction of the proboscis is probably due to

hydrostatic pressure created in the head fold by the contraction

of its musculature.

By dissection and actual observation of the effects produced by

electrical stimulation, the nervous supply for the apparatus

described has been in large part determined.

736 THE AMERICAN NATURALIST [Vor. XL

BIBLIOGRAPHY

AMAUDRUT, A.

’98. La partie antérieure du tube digestif et la torsion chez les mol-

lusques gastéropodes. Ann. Sci. Nat., zoöl., ser. 8, vol. 7, pp.

1-291, pls. 1-10.

Bovutan, L.

'86. Recherches sur l'anatomie et le développement de la fissurelle.

Arch. de Zool. Expér. et Gén., ser. 2, vol. 3, bis, pp. 1-173, pls.

31-44.

Bouvier, E. L.

'87. Systéme nerveux, morphologie générale et classification des

gastéropodes prosobranches. Ann. Sci. Nat., zoöl., ser. 7, vol. 3,

pp. 1-510, pls. 1-19.

'17. Mémoire pour servir à l'histoire et à l'anatomie des mollusques.

Paris, 4to.

GEDDES, P.

"T9. On the Mechanism of the Odontophore in Certain Mollusca.

Trans. Zool. Soc. London, vol. 10, pp. 485-491, pls. 80-82.

Gipson, R. J. H.

'87. Anatomy and Physiology of Patella vulgata. Trans. Roy. Soc.

Edinburgh, vol. 32, pp. 601-638, pls. 149-153.

Hoxtey, T.

'53. On du Morphology of the Cephalous Mollusea. Phil. Trans.

Roy. Soc. London, pp. 29—65, pls.

Lacaze-Duruiers, H.

'56. Histoire de l'organisation et du développement du dentale.

Ann. Sci. Nat., zoöl., ser. 4, vol. 6, pp. 225-281, pls. 8-10.

LorsEr, G.

’92. Sur l'appareil musculaire de la radula chez les Helix. Journ.

de l’Anat. et Physiol., vol. 28, pp. 567-572.

OSWALD, A.

'93. Der Rüsselapparat der Serra; Jen. Zeitschr. f. Naturw.,

vol. 28, pp. 119-162, pls. 5-

PELSENEER.

:06. Lankester’s Treatise on Zoology. Part 5 — Mollusca. London.

PraTE, L.

93. Studien über opisthopneumone Lungenschnecken. II. Die

Oneidiiden. Zoöl. Jahrb., Abth. f. Anat., vol. 7, pp. 93-234,

pls. 7-12. l

No. 478] ODONTOPHORAL APPARATUS IN SYCOTYPUS 737

SIMROTH, H.

:00. Bronn’s Klassen und Ordnungen des Thier-Reichs. Band 3.

Leipzig.

Tryon, G. W

'81. Manual of Conchology, ser. 1, vol. 3. Phila., 8vo, 310 pp.,

87 pls.

"WEGMANN, H.

'84. Contribution à l'histoire naturelle des Haliotides. Arch. Zool.

Exper. et Gén., ser. 2, vol. 2, pp. 289-378, pls. 15-19.

NOTES AND LITERATURE

BIOLOGY

Loeb's Dynamics of Living Matter.'— The point of view of Pro-

fessor Loeb’s new book will be surmised by those acquainted with

his other writings. Living organisms are to be considered as chemi-

cal machines which differ fundamentally from any machines so far

created by man in possessing the peculiarities of automatically devel-

oping, preserving, and reproducing themselves. In this volume we

have an attempt to analyze the strictly biological phenomena of

development, self-preservation, and reproduction from a purely

physico-chemical point of view.

Inasmuch as the material and the energy of organisms must be

supplied by chemical processes, it is only natural that this subject

should receive the first attention. Two lectures are therefore devoted

to the general chemical and physical problems involved in a study of

living matter.

These two lectures are followed by three of particular interest to

the physiologist. Hypotheses of muscular contraction and proto-

plasmic motion and the physical and chemical factors involved in cell

division are treated and an entire chapter is devoted to the important

subject of the röle of electrolytes in the formation and preservation of

living matter, and another to the effect of heat and radiant energy

upon living matter.

While these chapters are especially commended to the physiologist,

it does not follow that they are lacking in interest to the biologist whose

work touches only incidentally upon modern physiology. But to the

mind of the reviewer the first six chapters are of more interest to the

physiologist while the final six will be read with the keenest interest

by the general biologist as well.

In the chapter on tropisms the essential similarity of tropic responses

in animals and plants is considered and in so far as possible all are

referred to physico-chemical forces. This presents no great difficulty

1 Loeb, J. The Dynamics of Living Matter. Columbia University Bio-

logical Series VIII. New York, The MacMillan Company, 1906. 8vo, xi

+233 pp., 64 text-figs. $3.00.

739

740 THE AMERICAN NATURALIST [Vor. XL

in the case of heliotropism, galvanotropism, and chemotropism, but

geotropism and stereotropism are more difficult to explain. The

relation of the reactions to lines of force and the reason for this relation

are made clear. The discussion of the control of the degree and the

sense of heliotropic response is especially interesting. ‘The demon-

stration of the possibility of controlling these reactions by chemical

and other means, the apparent uselessness of many of them, and the

fact that many could never be used at all in Nature tend to show that

they could not have been acquired by way of natural selection.

The chapters on fertilization and heredity will probably be the

first to be read by many biologists. Two effects of the entrance of a

spermatozoón into an egg must be distinguished. The first is the

starting of the process of development, the developmental effects,

while the second is the transmission of the paternal qualities to the

organism, the hereditary effect. Under the first of these heads are

considered the specific character of the fertilizing power of the sperma-

tozoön, and its modification by chemical means — so that forms

otherwise incapable of crossings may be hybridized — and the prin-

ciples and results of experiments in artificial parthenogenesis. While

the development of the egg may be caused without the presence of

a sperm nucleus or an enucleated fragment of egg protoplasm may be

caused to develop by fertilization by a spermatozoón, we must recog-

nize the hereditary effect of egg or sperm nucleus as a distinct phe-

nomenon. 'The structure of the gametes is exceedingly simple and

yet instincts as well as bodily form are transmitted through the sexual

cells. Obviously purely morphological conceptions cannot carry us

very far here and we first think of definite chemical compounds as

the bearers of hereditary qualities. The evidence afforded by experi-

ments upon the toxic effect of the blood of a different species seems

significant in this connection but our real knowledge of these phe-

nomena is very meager and it seems impossible to draw any far-reach-

ing inferences.

'The minute size of the gametes precludes any extensive analyses of

the physico-chemical processes concerned in the formation of organs,

but the conditions of morphogenesis may be studied in regenerative

processes. Loeb follows Sachs in the view that the variety in the form

of organs is determined by a corresponding variety in their chemical

constitution and advances arguments from heteromorphosis in vari-

ous forms. The influence of the central nervous system is dis-

cussed and the possibility of the conduction of definite chemical

Substances to or from the ganglia is suggested

No. 478] NOTES AND LITERATURE 741

It is hardly necessary to state that in so far as views on evolution

are expressed they are Ssobntially de Vriesian and with the acceptance

of the validity of de Vries’s conclusions concerning discontinuity, there

is the suggestion of the physico-chemical nature of discontinuity in

evolutionary transformations.

The Columbia University Biological Series is so familiar to natural-

ists that comment upon the attractiveness of the volume is quite super-

fluous and we may simply say that the general scientific public is to

be congratulated on having in a condensed form the point of view and

chief results of the school of biologists of which Professor Loeb is our

best known advocate.

J. A. Harris

ZOOLOGY

Capture of the Salamander, Autodax lugubris, at Los Angeles, Cal.

— One of the points of interest concerning the genus Autodax is its

extremely limited range. The taking of a specimen of A. lugubris

in Los Angeles, Cal., a locality at a considerable distance from what

has heretofore been considered the center of its distribution, seems

of sufficient importance, therefore, to justify this note on the subject.

In a previous paper on the species by Professor Ritter and myself

(Amer. Nat., vol. 33, pp. 691-704, 1899), mention is made of the dis-

tribution of the genus as follows: “ Autodax is a genus of salamanders

confined, according to our present knowledge, to western North

America and almost entirely to California." Cope (U. S. Nat. Mus.,

bull. 34) states that ‘‘no species has yet been found east of the Paci-

fic coast region." He describes the three species of the genus from

specimens in the U. S. National Museum which are distributed as fol-

OWS:—

16 specimens, Petaluma, Cal. Lat. 38° 15’ N.

5 “ à

arallone Is. or ay *

10 " San Francisco 979 40' “

4 M Berkeley BEE ^

7 eu Monterey 36° 45' *

1 = Fort Tejon ar o "

Range 3° 15

742 THE AMERICAN NATURALIST [Vor. XL.

A. ferreus, 1 specimen, Ft. Umpqua, Ore.

A. iécanus, 2 specimens, Baird, Cal., Lat. 40° 50’ N.

The range of A. iécanus was extended by Van Denburgh (Proc.

Cal. Acad. Sci, n. s., vol. 5, pp. 776-778, 1895) southward to Los

Gatos, Cal., Lat. 37° 10’ N. Range, 3° 10’.

Omitting the little known A. jerreus, the others of the genus have

a range in central California of very narrow limits. Cope sums up the

evidence for the better known A. lugubris as follows: “The range of

this species is limited, embracing only middle California.”

The observations of Professor Ritter and myself (Amer. Nat., vol. 33,

pp. 691-704, 1899; vol. 37, pp. 883-886, 1903) show its comparative

abundance in the whole San Francisco Bay region. In fact, Monterey

and Fort Tejon are the only localities outside the bay region from

which it has previously been recorded. The remarkable occurrence

on the rocky Farallone Island 30 miles off shore was also re-established

by a party from the University of California under Professor ‘Torrey

in 1903.

The specimen taken in Los Angeles, Lat. 33° 40’ N., extends the

range a degree southward thus increasing the previously known range:

by almost 33%. The occurrence is further striking in that there is a

decided climatic difference between this locality and the bay region.

The temperature averages of the bay region range from 52°to60° and

those of the Los Angeles region from 60? to 68°. The low average

humidity of the Los Angeles region makes this difference even more

pronounced. Again, the two localities are separated by barriers of

desert and mountain ranges running at right angles to the coast line,

a combination of conditions which suffices to isolate several subspecies

of birds in the Los Angeles region by checking the north and south

diffusion. A. lugubris seems, then, to be less timorous than we had

at first thought.

The Los Angeles specimen was taken on March 18 of this year,.

which date is in the midst of the rainy season. The animal was found

under a rotten log in just such surroundings as one would expect to-

find the species in the bay region. The appearance is that of a typical

. specimen of the third year except that the lemon yellow spots are

slightly more numerous than in the majority of specimens from the

bay region. Only one specimen was taken but the fact is of minor

significance as the species is a bit erratic in its distribution in the bay

region.

Love Horwres MILLER

No. 478] NOTES AND LITERATURE 743

Pimephales notatus in the Lower Susquehanna.— This fish is said

to range from Quebec to Delaware and west in the Mississippi valley,

thus embracing the above-named river basin where, however, I have

not found it recorded before. A number of examples, one a breeding

male, was secured by Mr. Witmer Stone and myself while at York

Furnace, York Co., Pa., during the middle of May. Alosa sapidis-

sima, Anguilla chrisypa, Brama crysoleucas, Notropis bifrenatus, N.

analostanus, Rhinichthys atronasus, Hybopsis kentuckiensis, Ameiu-

rus nebulosus, Fundulus diaphanus, Lepomis auritus, Eupomotis

gibbosus, Perca flavescens, Boleosoma nigrum olmstedi, Plethodon

erythronotus, P. glutinosus, Diemyetylus viridescens, D. miniatus,

Desmognathus fuscus, Acris gryllus crepitans, Hyla pickeringü, H.

versicolor, Rana palustris, R. clamata, R. catesbiana, R. pipiens,

Natrix sipedon, Thamnophis sirtalis, Chrysemys picta, and Terrapene

carolina were taken, seen, or heard. With the exception of a single

small Exoglossum maxillingua found in Otter Creek, no fishes were

obtained in any of the nearby tributaries, all of which are swift, rocky,

and of rapid descent. Besides the above, Petromyzon marinus, Pomo-

lobus pseudoharengus, Salvelinus fontinalis, Ameiurus catus, Stizo-

stedion vitreum, Roccus americanus, Morone americanus, and Crypto-

branchus alleganiensis were reported to occur though we did not see

any examples.

Henry W. FOWLER

Notes.—Origin of the Vascular Endothelium and of the Blood in

Amphibia. — Kati Marcinowski has attacked this vexed problem,

using for his material Siredon and Bufo. His results are summa-

rized as follows (Jen. Zeitschr., vol. 34, 1906) :—

The vascular endothelium arises from the mesenchyme and

chiefly and possibly exclusively from the secondary mesenchyme.

he primary mesenchyme which perhaps contributes, is derived from

the ectoderm. No traces were seen of the origin of mesenchyme from

the entoderm.

Vascular and blood formation is localized in two regions which in

position correspond to the site of the dorsal and ventral mesenteries

— sclerotomal and medioventral mesoderm regions. Besides the

formation of endothelia from localized anlagen there is also a similar

formation from diffusely appearing wandering cells and in connective

tissue.

In their first appearance the results are either solid at first and at

the first appearance of a lumen are closed to all other cavities or they

744 THE AMERICAN NATURALIST [Vor. XL

are open and connect with other spaces in the mesenchyme or con-

nective tissue. The differences in method of formation are refer-

able to locally different conditions of development and have no

important morphological value.

The endothelium arises at a time when the blood corpuscles are

in circulation in connection with lacune, the schizoccele, in the

connective tissue and is to be regarded as arising phylogenetically

rom a lacunar system bounded by connective tissue whose physi-

ologically most important and hence earliest differentiated portion

lay in the region of the gut.

The localization of the blood and vascular forming cells in the

region of the mesenteries confirms the view of Lang, founded on

comparative anatomy, that the first differentiation of the intestinal

blood sinus of the Cœlomata occurred in the separation of vessels in

the region of the dorsal and ventral mesenteries.

The blood corpuscles are to be regarded as ‘swimming mesen-

chyme cells’ in Ziegler’s sense. They arise in the medio-ventral

mesoderm region.

d SLK:

BOTANY.

Notes.— The concluding fascicle (parts 5 to 9) of vol. 8 of the

Reports of the Princeton University Expeditions to Patagonia, which

is devoted to an account of the flowering plants by Professor Macloskie,

was issued on February 26th. It brings the total pagination for the

quarto volume up to 982 and the plates to 31; and in addition to the

conclusion of the list of species contains an analysis of orders and

families, a list of collectors, with bibliography, an account of the

topography of the country, and a Chapter on the character and origin

of the Patagonian flora.

Vol. 4 of Reiche’s Flora de Chile completes the Composite and

contains correction sheets for the first four volumes.

A third “Contribution to the Flora of the Bahama Islands,” by

Britton, is separately issued from vol. 4 of the Bulletin of the New

York Botanical Garden, under date of March 19.

No. 478] NOTES AND LITERATURE 745.

Under the title ‘‘Preenuncize Bahamenses," Millspaugh begins a

series of contributions to a flora of the Bahaman archipelago, the first.

part, issued as Publication 106 of the Field Columbian Museum in

February, dealing with Amaranthacex, Euphorbiacex, Rubiacee,.

Verbenacex, and Solanum didymacanthum.

A list of pteridophytes and flowering plants collected in Bermuda.

in 1905 has been privately printed by A. H. Moore, of Cambridge,

who describes two species of phanerogams as new.

A local flora of the region readily accessible from Philadelphia has.

been published by the Botanical Club of that city, and is offered for

sale by Mr. Stewardson Brown, who, with Dr. Ida Keller, has edited.

it.

Talbot is publishing an account of the distribution of the forest flora.

of the Bombay Presidency and Sind, in current issues of The Indian.

Forester.

A list of pteridophytes and spermatophytes of Delaware County,

Pa., is published by Fussell in the Proceedings of the Delaware County

Institute of Science, of Media, Pa.

An illustrated account of native edible plants, by seasons, is being:

printed by Rusby in current issues of Country Life in America.

A popular guide to the commoner North American trees, intended.

for the novice and largely illustrated, has been issued by Julia E.

Rogers from the press of Doubleday, Page, and Co., of New York.

Volume 1 of de Wildeman’s “ Etudes de systématique et de géo-

graphie botanique sur la flore du Bas et Mayen-Congo " has been

completed by the issuance of a third fascicle from the press of the

Musée du Congo of Brussels. The volume, in quarto, contains 346

pages and 73 plates. -

A list of 30timbert tive tothe State, with good barkand wood

photograms of each, is given by Douglass in the fifth Annual Report

of the State Board of Forestry of Indiana,— which contains other

interesting papers on the trees of the State and their enemies.

An account of the southern Appalachian forests, by Ayres and Ashe,

constitutes Professional Paper No. 37 of the U. S. Geological Survey.

Lemmon gives a profusely illustrated account of Californian trees.

in Out West, for March.

746 THE AMERICAN NATURALIST [Vor. XL

The Flora of Tropical Africa, under the editorship of Sir W. T.

Thiselton-Dyer, reaches Buchnera in vol. 4, sect. 2, part 2, recently

issued.

An illustrated paper on new American Coralline alge, by Foslie

and Howe, is separately distributed from vol. 4 of the Bulletin of the

New York Botanical Garden.

An account of the foliaceous and fruticose lichens of the Santa Cruz

Peninsula, California, by Herre, forms a brochure of the Proceedings

of the Washington Academy of Sciences issued on March 29.

A medico-legal study of the spores of the higher fungi is published

by Offner in vol. 34 of the Bulletin de la Société de Statistique... .de

l'Iséve.

A thesis on the nature and origin of the binucleated cells in some

Basidiomycetes, by Susie P. Nichols, is separately issued from vol. 15

of the Transactions of the Wisconsin Academy of Sciences, Arts, and

Letters.

The morphology of Gymnosporangium galls forms the subject of a

paper by de Lamarliére in the Annales des Sciences Naturelles,

Botanique, of March.

A further contribution to the literature of sexuality in Uredinese

is made by Blackman and Fraser in the Annals of Botany for January.

An extensive paper on the origin and distribution of rust diseases is

contributed by Eriksson to the Arkiv för Botanik, vol. 5, parts 1-2.

An economic account of Glomerella rujomaculans, by Scott, forms

Bulletin no. 93 of the Bureau of Plant Industry, U. S. Department of

Agriculture.

Rehm continues his descriptions of North American Ascomycetes

in Annales Mycologict.

A paper on new or rare Pyrenomycetez from western New York,

by Fairman, forms a brochure of the Proceedings of the Rochester

Academy of Science, issued in March.

The fungi of Camembert and Roquefort cheese, from which Peni-

cillium camemberti and P. roqueforti are described and figured as new,

are discussed by Thom in Bulletin no. 82 of the Bureau of Animal

Industry, U. S. Department of Agriculture.

No. 478] NOTES AND LITERATURE 747

Thaxter’s group of Myxobacteria is the subject of an extensive

illustrated article by Quehl in the Centralblatt für Bakteriologie, etc.,

2 Abteilung, of March 6.

The deterioration of commercial cultures for legumes is noted in

Bulletin no. 270 of the New York Agricultural Experiment Station.

An account of Bacillus necrophorus and its economic importance,

by Mohler and Morse, forms Circular no. 91 of the Bureau of Animal

Industry, U. S. Department of Agriculture.

A further discussion of the effect of drying upon the bacteria of

leguminous root tubercles is contributed by Kellerman and Beckwith

to Science of March 23.

A paper on the bacterial flora of the city water of Madrid is pub-

lished by Madrid Moreno as vol. 3, no. 2, of the Memorias de la Real

Sociedad Espanola de Historia Natural.

Bacillus nicotiane, causing a wilt disease of tobacco, is described

by Uyeda in vol. 1, no. 1, of the Bulletin of the Imperial Central Agri-

cultural Experiment Station of Japan, issued in December last.

A new presentation of Myrmecophily, with interesting illustrations,

is given by Ule in Engler’s Botanische Jahrbücher of February 27.

A recent number of the Allgemeine botanische Zeitschrift notes that

in the Königsberg district a fine of 150 Marks has been recently pre-

scribed as the penalty for each offense, as a means of stopping the

extermination of a rare plant — Eryngium maritimum.

The second part of Wittrock's “Catalogus Illustratus Iconothece

Botanice Horti Bergiani Stockholmiensis," constituting vol. 3, no. 3,

of the Acta Horti Bergiani, is a thick volume with 151 plates of por-

traits.

A sketch of Woronin's life, with portrait and bibliography, is con-

tained in a recently issued fascicle of the Travaux du Musée Botanique

de l'Académie Impériale des Sciences de St. Pétersbourg.

A further “coöperative memoir" on inheritance in the Shirley

poppies, with a color plate of petals, is published in Biometrika for

March.

An account of some of the old herbaria and books of Cassel is given

by Schelenz in no. 49 of the Abhandlungen und Bericht des Vereins

fiir Naturkunde zu Cassel.

748 THE AMERICAN NATURALIST [Vor. XL

The dedication of more than one genus to a given individual is the

subject of protest by Greene in a signature of his Leaflets issued on

April 10.

Osterhout publishes papers on osmotic and toxic questions in a

brochure of the University of California Publications, Botany, issued

on March 13.

“The Vital Fabric of Descent” is the title of a further presentation

of his kinetic theory of evolution, by O. F. Cook, in a brochure of

Proceedings of the Washington Academy of Sciences, issued on March

19.

A posthumous paper by Songeon on the mode of development of

the vegetative organs of a large number of the plants of Savoy is pub-

lished in vol. 10 of the second series of the Bulletin de la Société d' H is-

toire Naturelle de Savoie.

A note on protective resemblances in Mesembryanthemum and

Anacampseros, by Thiselton-Dyer, is published in the Annals of

Botany for April, with good illustrations which, however, are mutilated

by the method of insertion in the journal.

A popular lecture on the sensitiveness of plants is separately issued

by Kny from vol. 20 of the Naturwissenschaftliche Wochenschrift.

Recent studies of the reduction division in the sexual nuclei of plants

are summarized by Agnes Robertson i in the opening number for 1906

of The New Phytologist.

A handbook of plant-breeding applied to a number of important

crops, by Fruwirth, is being issued from the Parey press of Berlin.

Rubber culture in Mexico is the subject of an illustrated article by

Main in The American Inventor for April.

An anatomical study of some plants which yield gutta-percha is

being published by Charlier in current issues of the Journal de Bota-

nique.

A readable illustrated article on the plant introduction work of the

national Department of Agriculture, by Fairchild, appears in The

National Geographic Magazine for April.

Some sensible ideas on high-school teaching of biology are given by

Elma Chandler in School Science and Mathematics for May.

No. 478] NOTES AND LITERATURE 749

Extensive segregation and nomenclatorial revision in a number of

groups of phanerogams are contained in recently issued signatures of

Professor Greene's Leaflets.

Hefte 23 (Halorrhagacex, by Schindler) and 24 (Aponogetonace:e,

by Krause and Engler) of Engler's Das Pjlanzenreich have been

issued recently from the Engelmann press of Leipzig.

An account is given by Graebener, in the Mitteilungen der deutschen

dendrologischen Gesellschaft for 1905, of the Magnolias found hardy

in Germany, and is accompanied by a distributional map for those

native to the United States. A garden account of the same genus is

also published by Miller in The Garden Magazine for June.

A revision of the American species of Parthenocissus is published

by Rehder in Mitteilungen der deutschen dendrologischen Gesellschaft

for 1905, which also includes an account of Cercocarpus, by Schneider.

A number of new American species of Ribes are described in the

second and third parts of Janczewski's revision of the genus, separately

issued in January and May from the Bulletin International de l Aca-

démie des Sciences de Cracovie.

A new Burmese species of Eugenia is described and figured by Gage

in The Indian Forester for January.

A paper on alfalfa seed and its adulterants and impurities, by

Roberts and Freeman, forms Bulletin no. 133 of the Kansas State

Agricultural College.

White publishes an account of Robinia and its enemies in The

Popular Science Monthly for March. '

. Rubus flavinanus and R. grontianus are described from Vermont, as

new, by Blanchard in The American Botanist of April and May.

A note by Ellwanger on Crataegus ellwangeriana, with illustration,

is published in Gardening Illustrated of May 5.

Four new cacti from Mexico are described by Roland-Gosselin

in vol. 11, no. 6, of the Bulletin du Museum d’Histoire Naturelle of

Paris.

A second part of Burgess’ “Studies in the History and Variation of

Asters,” dealing with the group Biotia and containing a general dis-

cussion of variability in the genus, forms vol. 13 of the Memoirs of

the Torrey Botanical Club, issued on March 15.

750 THE AMERICAN NATURALIST [Vor. XL

Anatomical studies of Valerianacez are published by Vidal in vol.

34 of the Bulletin de la Société de Statistique... . de l Isère.

Contrasting seed-figures of Catalpa speciosa and C. bignonioides

are given in Arboriculture for May.

The Nepenthes of Madagascar and New Caledonia are revised by

Dubard in no. 1 of the Bulletin du Muséum d’ Histoire Naturelle of

Paris, for 1906.

Courchet has a paper on the morphology and anatomy of Eperua

falcata in the Annales de l'Institut Colonial de Marseille, of 1905.

A morphological-anatomical study of Hura is contributed by Gilles

to the 1905 Annales de l'Institut Colonial de Marseille.

A volume of nearly 100 drawings by W. H. Gibson, with descrip-

tive text by Helena Leeming Jelliffe, is published by Doubleday, Page,

and Co., under the title Our Native Orchids. Like all of Gibson's

work it is sketchy and calculated to stimulate interest in the subjects

depicted.

An account of the different sarsaparillas of commerce — without

determinations of the species of Smilax that furnish them — is given

by Henry in vol. 14, no. 2, of the Bulletin de la Société Scientifique et

Médicale de l'Ouest.

Habit and trunk pictures of Ficus benghalensis are given in Forest

Leaves for April.

An account of his hybrids of Yucca flaccida, Y. filamentosa, and

Y. treculeana with other species of the genus is given by Sprenger in

recent issues of the Bullettino della R. Società Toscana di Orticultura.

The North American species of Festuca are revised by Piper in

vol. 10, part 1, of Contributions from the U. S. National Herbarium,

dated March 30.

An economic account of Allium vineale as a wheat weed is given by

Duvel in Bulletin no. 100 of the Bureau of Plant Industry, U. S.

Department of Agriculture.

A very broad-leaved cultivated form of Hesperoyucca is described

in the Gardeners’ C hronicle of March 10 under the name Yucca nitida

Wright MS.

An extensive paper on the comparative anatomy and phylogeny of

Cyperacez is published by Plowman in the Annals of Botany for

January.

No. 478] NOTES AND LITERATURE 751

A list of Ottawa Eriophorums is given by Macoun in The Ottawa

Naturalist for May.

Papers on Calamagrostis, by Forges and Lehbert, with spikelet

illustrations, are contained in the Mitteilungen des thüringischen

botanischen Vereins, n. f., heft 20.

Enzyme-poison production in Zea is noted by Price in Circular no.

84 of the Bureau of Animal Industry, U. S. Department of Agriculture.

An account of the poisoning of horses in South Africa by Ornitho-

galum thyrsoides is given by Hutcheon in the Agricultural Journal of

the Cape oj Good Hope for February; and Delphinium and other

stock-poisoning plants of Colorado form the subject of Bulletin 113

of the Experiment Station of that State, by Glover. i

The natural replacement of Pinus strobus in old fields in New

England is the subject of Bulletin no. 63, Bureau of Forestry, U. S.

Department of Agriculture, by Spring.

A practical little book on Ferns and How to Grow Them, by Woolson,

has been issued from the Doubleday Page press of New York.

A new segregate of the ternatum group of Botrychium is published

by Maxon, under the name B. alabamense in a leaflet of the Proceed-

ings of the Biological Society of Washington, issued on February 26.

Léveillé notes the occurrence of Azolla caroliniana in China, in the

February-March fascicle of the Bulletin de l' Académie Internationale

de Géographie Botanique.

The Journals.— Botanical Gazette, February: — Fulton, ** Chemo-

tropism of Fungi"; Lewis, “The Embryology and Development of

Riccia lutescens and Riccia crystallina” ; Livingston, “Note on the

Relation Between Growth of Roots and of Tops in Wheat."

Botanical Gazette, March: — Simons, “A Morphological Study of

Sargassum filipendula" ; Schaffner, “Chromosome Reduction in the

Microsporocytes of Lilium tigrinum”; Olive, ‘Cytological Studies

on the Entomophthoree — I"; Ganong, “New Normal Appliances

for Use in Plant Physiology — III."

Botanical Gazette, April: — Olive, “Cytological Studies on the

Entomophthoree — II"; Spalding, “Biological Relations of Desert

Shrubs — II"; Eastwood, “New Species of Californian Plants”;

Hitchcock, ‘‘Notes on North American Grasses — VI."

752 THE AMERICAN NATURALIST [Vor. XL

<, “Further Notes on Cladonias —

VI”; Grout, “Additions to the Bryophyte Flora of Long Island”;

Holzinger, “Grimmia glauca — a New Species or a Hybrid”; Howe,

“ Ramalina rigida on the Rhode Island Coast”; Hill, ** Encalypta

procera —a Correction”; Watts, ‘Australian Mosses —Some Locality

Pictures."

The Bryologist, May: — Britton, “Notes on Nomenclature — VI”;

Watts, “Australian Mosses — Some Locality Pictures”; Grout,

“Bryological Notes"; Howe, “Some Lichens of Mt. Watatic, Mass.” ;

Harris, “A List of Foliaceous and Fruticose Lichens Collected at

Chilson Lake, Essex Co., N. Y."; Howe, “ Ramalina rigida in Mass." ;

Towle, “ Notes on the Life Hiddery of the Mniums."

Bulletin of the Southern California Academy of Sciences, December,

1905: — Pfarish], “Cereus giganteus in California"; Hasse, “A Few

Lichens picked up on San Jacinto Mountain”; Parish, “A Prelimi-

nary Synopsis of the Southern California Cyperaceze — VIII.”

Bulletin oj the Southern California Academy of Sciences, March: —

Davidson, “A Revision of the Western Mentzelias"; Parish, “A

Preliminary Synopsis of the Southern California One ai,

Grant, ‘‘Wheelerella.”

Bulletin of the Torrey Botanical Club, February: —Selby, “Studies

in Etiolation”; Kraemer, “Studies on Color in Plants”; Randolph,

“The Influence of Moisture upon the Formation of Roots by Cuttings

of Ivy”; Underwood and Lloyd, ‘The Species of Lycopodium of the

American Tropics.”

Bulletin of the Torrey Botanical Club, March: — Evans, “The

Hepatic of Bermuda”; Rydberg, “Studies on the Rocky Mountain

Flora — XVI"; Berry, ‘Contributions to the Mesozoic Flora of the

Atlantic Coastal Plain — I”; Gleason, “The Genus Vernonia in the

Bahamas”; Underwood, “American Ferns — VI, Species Added to

the Flora of the United States from 1900 to 1905.”

hess of the Torrey Botanical Club, April: — Peck, ** New Species

of Fungi"; Harris, “The Anomalous Anther-Structure of Dicorynia,

Duperquetis, and Strumpfia"; Harper, “Some New or Otherwise

Noteworthy Plants from the Constel Plain of Georgia”; Stockard,

“Cytological Changes accompanying Secretion in the Nectar-Glands

of Vicia faba."

The Fern Bulletin, January: — Bissell, “The Fern Flora of Con-

necticut”; Davenport, “Botrychium matricariefolium”; Durand,

No. 478] NOTES AND LITERATURE 753

„

; Clute, ` Eropiesl Ferns in Southern States” ;

3».

“Sporangial Trichomes

Hazen, “Dryopteris Pr in Vt.”

The Fern Bulletin, April: — Gilbert, Pe vulgare and its

Varieties in America”; Rooney, “The Resting of Botrychium”;

Clute, ‘“ The Forms of the Cinnamon Fern”; Dukes, “An Alsina

Station for Botrychium biternatum" ; Clute, “The Author Citation”;

Winslow, “The Distribution of Botrychia"; Clute, ''Polypodium

piloselloides."

Journal of Mycology, January: — Morgan, “North American

Species of Marasmius" (continued); Kellerman, ‘‘Uredineous Cul-

ture Experiments with Puccinia sorghi, 1905”; Arthur, “‘Cultures

of Uredinez in 1905"; Durand, “Peziza fusicarpa Ger. and Peziza

semitosta B. & C."; Kellerman, “Notes from Mycological Literature

— XVII.”

Journal of the New York Botanical Garden, February: — Nash,

“Notes from the Conservatories”; Wilson, ‘The American Dragon's

Blood Tree.”

Journal of the New York Botanical Garden, March: — Nash, “A

Guide to the Conservatories.”

Journal of the New York Botanical Garden, April: — Robinson,

“The History of Botany in the ERAPPUR Islands”; Rusby, “A

Floating Orchid ee repens)"; Hollick, “The Type of

Zamites montanensis Font

Muhlenbergia, vol. 1, no. 8 (April, TUDI: == Honat; ** Nomencla-

torial Changes in the Orchidacese"; House, “A New pea of

Dichondra”; [Heller], “Western Species; New and Old — V."

Ohio Naturalist, February: — Schaffner, “Check List of Ohio

Trees”; Sumstine, “Notes on Anthurus borealis”; Schaffner, ‘‘Sex-

ual and Nonsexual Generations."

Ohio Naturalist, March: — Fischer, “New and Rare Ohio Plants”;

Moseley, ‘The Cause of Trembles in Cattle, Sheep and Horses, and

of Milk-sickness in People” (continued); Schaffner, “The Life

Cycle of a Homosporous Pteridophyte”; Jennings, “Some New or

Noteworthy Species Reported for Ohio in Recent Botanical Litera-

re"; McOwen, “Key to Ohio Catalpas in Winter Condition."

Ohio Naturalist, April: — Fischer, “Ecological Observations on

the Flora of the Shale Bluffs in the Vicinity of Columbus, O.”;

Claassen, “Corrections to the Key to Liverworts”; Schaffner, “‘Win-

754 THE AMERICAN NATURALIST [Vor. XL

ter Buds of Ohio Trees and Shrubs”; Van Hock, “ Aschochyta pis —

a Disease of Seed Peas”; Schaffner, ‘“ The Classification of Plants —

III”; Morse, “Key to Ohio Alders in Winter Condition”; Stock-

berger, “Further Notes on Anthurus borealis."

[Publication] no. 35 of the Manila Bureau of Government Labora-

tories, issued on January 17, contains part 4 of Merrill’s “New or

Noteworthy Philippine Plants," *Notes on Cuming's Philippine

Plants" by the same author, “Notes on Philippine Grasses” | by

Hackel, Scitaminez by Ridley, and Acanthacex by Clarke.

The opening numbers of The Philippine Journal of Science contain

several papers on Cocos.

Plant World, January: — Hitchcock, “Twigs of Woody Plants”;

Livingston, “ A Simple Method for Experiments with Water Cultures " ;

Van Hook, “The Hop-hornbeam or Ironwood”; d The

Devil’s Tongue.”

Plant World, February: — Wiegand, “The Occurrence of Ice in

Plant Tissue”; Taylor, “The Georgia Bark or Quinine Tree (Pinck-

neya pubens)”; Koch, “Floral Notes of Foreign Lands."

Plant World, March: — Cannon,“ Two Miles Up and Down in an

Arizona Desert”; Lloyd, ‘The Artificial Induction of Leaf Formation

in the Ocotillo” [from Torreya]; Koch, “Floral Notes of} Foreign

Lands" (conclusion); Livingston, “‘Paraffined Wire Pots for. Soil

Cultures.”

Plant World, April:— Leavitt, “The Blooming of an Unusual

Orchid"; Niles, “Our Moccasin Flowers and other Orchids at

Home"; Blumer, “Two Junipers of the Southwest."

Rhodora, February: — Bartlett, “The Salt-Marsh Iva of New

England"; Harper, “Further Remarks on the Coastal Plain Plants

of New England, their History and Distribution”; Fernald, “Some

American Representatives of Arenaria verna"; Evans, ‘Notes on

New England Hepatieze — IV”; Fernald, “Two Variations of Carex

glareosa” ; Weatherby, “An Extreme Form of Botrychium virginia-

num”; Slade, “Early Flowering of Hepatica triloba."

Rhodora, March: — Brainerd, **Hybridism in the Genus Viola —

MI Andrews, “Preliminary Lists of New England Plants — XVIII,

Sphagnacee”’; Knight, “Some Noteworthy Plants of the Penobscot

Valley"; Riddle, “Contributions to the Cytology of the Entomoph-

oracese — Preliminary Communication”; Smith, “A New Station

for Asplenium ebenoides.”

No. 478] NOTES AND LITERATURE 755

Rhodora, April: — Fernald, “The Genus Streptopus in Eastern

America”; Knight, “Notes on some Plants of Bangor, Maine”; Fer-

nald, “ The Variations of Carex paupercula”; Collins, “Intuition as a

Substitute for Reference.”

Torreya, February: — Cannon, ‘The Effects of High Relative

Humidity on Plants"; Harris, “Syncarpy in Martynia lutea" ; Britton,

“Notes on West Indian Crucifer®”; Parish, “ Teratological Notes”;

Murrill, “The Pileate Polyporacex of Central Maine.”

Torreya, March: — Harper, “A November Day in the Upper Part.

of the Coastal Plain of North Carolina”; Nash, “A New Begonia

from Bolivia”; Massee, “A Fungus Parasitic on a Moss”; Rusby,.

“The Home of Dudleya rusbyi."

Torreya, April: — Griffiths, ‘‘Abnormalities in the Fruiting Habits.

of Opuntias"; Eggleston, ‘‘Crateegus of Dutchess County, N. Y.";

Van Hook, “A Cause of Freak Peas."

Transactions of the American Microscopical Society, vol. 26: —

urrill, “Micro-organisms of the Soil and Human Welfare"; Cle-

ments, “Relation of Leaf-Structure to Physical Factors"; Bessey,

"Structure and Classification of the Lower Green Algz.”

Transactions of the Kansas Academy of Science, vol. 20, part 1: —

Coppedge, “The Effect of Light on Melilotus alba”; Sayre, “The

Botanical Features of the New United States Pharmacopeia”;

Meeker, “A Little Experiment in Flower Making”; Reagan, ‘‘ Notes.

on the Flora of the Rosebud Indian Reservation, South Dakota.”

Report of the Michigan Academy of Science, vol. 7:— Beal, “ Vitality

of Seeds"; Dandeno, ‘‘ Color’ Stimulus and Vital Functions of

Plants"; Bach, “Toxic Action of Copper er wen upon Certain Algse

in the Povbenos of Foreign Substances"; Loew, “A Study of the

Effects of Dilute Solutions of Hydrchjone Acid upon the Radicles of

Corn Seedlings”; Pollock, “Notes on Ganoderma sessile" ; “ A Canker

of the Yellow Birch and a Nectria Associated with it"; .'*A Species of

Hormodendrum on Araucaria”; Pollock and Kauffman, “Michigan

Fungi"; Stearns, “A Study of Plants in Ravines near Adrian”;

Trace, “Climatic Centers and Centers of Plant Distribution";

iude “Winter Field Work in Botany"; Levy, '"'Anthrax-like

Bacilli

(No. 477 was issued September 21, 1906)

There is

no page numbered

756.

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VOL. XL, NO. 479 NOVEMBER, 1906

THE

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NATURALIST

A MONTHLY JOURNAL

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IN THEIR WIDEST SENSE

CONTENTS

Page

I. Variation in the Number of Seeds ofthe Lotus . . DR. RAYMOND PEARL 757

II. The Causes of Extinction of Mammalia. . . PROFESSOR H. F. OSBORN 767

UI. A Preliminary Study of the Finer Structure of Arcella

A, CUSHMAN and W. P. HENDERSON 797

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THE

AMERICAN NATURALIST

Vor. XL November, 1906 No. 479

VARIATION IN THE NUMBER OF SEEDS OF THE

LOTUS

RAYMOND PEARL

In nis Mutationstheorie (vol. 1, p. 112) de Vries puts at the

head of a list of topics for further investigation by the student of

variation the following sentence: “Das Quetelet'sche Gesetz

bedarf immer weiterer Beispiele; die Zahl dieser kann nie gross

genug werden." In view of this statement from so distinguished

an investigator of the problems of evolution, I venture to publish

some material on variation in Nelumbium which has been in my

notes for some years and which has frequently been used as an

illustration in classroom lectures in biometry. As will be seen in

what follows, this material conforms very closely to the normal or

Gaussian law in the distribution of its variates; much more closely

in point of fact than do many cases which have commonly been

cited as typical illustrations of that law.

In marshy situations at many points about the shores of the

western part of Lake Erie the common lotus, Nelumbium luteum

Willd., grows in great abundance.’ Especially in a strip of water

known locally as “Black Channel,” which connects Sandusky

Bay with the lake, does this plant flourish. Many acres of water

are literally covered with its leaves. Pieters (loc. cit., p. 66) says

of the growth of Nelumbium in this region: “ The immense yellow

flowers rising just above the great dark-green standing leaves and

the water covered with huge floating pads make this the most

striking formation of the swamp. ‘The Nelumbium grows in from

1 Cf. Pieters, A. J. “The Plants of Western Lake Erie, with Observations

on their Distribution.” Bull. U. S. Fish Comm. 1901, pp. 57-79.

757

758 THE AMERICAN NATURALIST [Vor. XL

2 to 4 feet of water, or stray plants may be found in less than 2 feet.

Many of the floating leaves were 20 to 24 inches across and the

standing ones not much smaller. At Upper Sandusky Bay I

found a floating leaf 26 inches in diameter and another with a

petiole more than 5 feet in length. Both at Sandusky Bay and

along the Portage River the acreage of Nelumbium was greater

than at East Harbor, but nowhere did the plants present a more

vigorous growth or so magnificent an appearance. "'

'The large ovoid seeds of this plant are borne in pockets scattered

Fic. 1.— Showing the general form of the capsule and arrangement of the

in Nelu mbium, The two capsules shown in this photograph etiim. be

extremes of variation in the sample; the capsule on the left bore 9 seeds,

and the one on the right vain n the photograph both are reduced below

actual size to the same degr

over the flat, upper surface of the conical seed capsule. After the

flower has been shed the ends of the seeds are seen projecting from

these pockets. ‘The form of the capsule and the arrangement of

the seeds are shown in the accompanying photographs (Figs. 1,

2, and 3), for the preparation of which I am indebted to Miss Frances

J. Dunbar.

It is the purpose of the present paper to set forth the results of a

study of the variation in the number of seeds to the flower (or the

capsule) in this plant. At the end of the flowering season in the

summer of 1902 a series of 1410 seed capsules was collected at

random from the Black Channel fields in Sandusky Bay. A

No. 479] VARIATION IN LOTUS 759

count was made of the number of seeds in each of these capsules

and the records so obtained form the basis of this paper.

The raw data are exhibited in Table 1.

TABLE 1

Frequency Distribution of Number of Seeds in Nelumbium

Number of Number of Number of

Seeds per Frequency Seeds per Frequency Seeds per Frequency

Capsule Capsule Capsule

9 4 20 60 31 45

10 0 21 101 * 92 34

11 0 22 111 33 21

12 2 23 113 34 13

13 2 24 114 35 11

14 1 25 107 36 7

15 13 26 137 37 x

16 11 27 120 38 1

17 30 28 101 39 1

18 41 29 90

19 58 30 62 Total 1410

Fic. 2.— Showing two capsules of almost exactly the same size but bearing

widely different numbers of seeds, the one on the left having 15 seeds nes

the other has 31. It should be noted that the openings of the seed pocket

have been edérged with a knife in the specimen on the left. The wal

aspect of the capsule top is shown in the right-hand specimen,

The chief physical constants for this distribution are given in

able 2

760 THE AMERICAN NATURALIST [Vor. XL

TABLE 2

Constants for Variation in Seed Number in Nelumbium

Mean 24.874 + .078

Standard Deviation 4.339 + .055

Coéfficient of Variation 17.445 + .162

It will be noted that the distribution as a whole is quite symmetri-

cal. The relative variability, as measured by the coéfficient of vari-

ation, is of the same general order of magnitude as has been found

Fic. 3.— A large, fully developed capsule seen from the side;

in plant characters by other workers. In order to determine whether

or not the variation of the character under consideration follows the

normal law within the limits of the errors of random sampling we

must examine the values of the analytical constants, which define

the character of a frequency distribution, in comparison with their

probable errors. Using Sheppard's corrections for the moments

I find the values given in Table 3. The unit for the moments is 1

seed. :

No. 479] VARIATION IN LOTUS 761

TABLE 3

Analytical Constants for Variation in Nelumbium

Constant Value

Es 18.8307

Ha 2.4675

" 1022.5949 '

Bı 0.0009

/B, 0.0302

Bs 2.8838

Bs—3 —0. 1162

Kı —0.2351

Ka — 0.0029

Skewness 0.0164

Modal Divergence 0.0712

Standard Deviation 4.3394

Mean 24.8745

Mode 24.8033

Further, we have the following values for the probable errors of

the chief constants concerned in testing whether the distribution

sensibly deviates from the normal law. It will be understood

that these are the values of the probable errors for the normal

curve.

Probable error of skewness = + 0.0220

V Bi = + 0.0440

[11 [11 [14 n: aus + 0. 0880

" “ * modal divergence = + 0.0955

We see at once that neither the skewness, the difference between

the mean and the mode, nor 4/0,, are sensibly different from what

they would be for an absolutely normal distribution. In the case

of each of these constants the theoretical value for a normal curve is

zero. The values found from the actual statistics in this reasonably

large sample differ from zero by less than the probable errors.

Hence we may conclude that in respect to number of seeds per cap-

sule Nelumbium varies symmetrically about the mean (which of

course coincides with the modal) condition. A half of the capsules

bear less than the typical number of seeds, and a half more than the

typical number. Turning to the quantity 8,— 3, which the

degree of flatness at the top of the curve, or, as it has been called

762 THE AMERICAN NATURALIST [Vor. XL

by Pearson,’ the kurtosis, the case is somewhat different. The-

oretically the normal curve is mesokurtic, or B,—3=0. Now in the

present case 8, —3 differs from zero by more than its probable error.

‘The deviation is less than twice the probable error of ß,, so cannot

be considered as significant on this basis. As we shall see, how-

ever, we get a somewhat better fit to the data given by the actual

sample if we use a curve which takes into account this deviation

from the mesokurtie condition of the normal curve. In so far,

however, as we may infer from the sample regarding the conditions

in the general population from which the sample is taken, we can

conclude with a high degree of probability that in the variation in

number of seeds per capsule .N elumbium follows the normal law of

errors.

From the values of x, and x, given in Table 3 we see that what-

ever deviation from normality exists, is in the direction of a curve

of Type 1. In order to compare the graduation given by a normal

and a skew curve, I have fitted both types of curve to the data.

The equation to the normal curve is

y = 129.6271 e 37-614

while the equation to the Type 1 curve is

X 421.7365

y = 127.6421 (1 + 387285) (

Calculating out the ordinates of these two curves corresponding

to the different numbers of seeds, we have the results shown in

Table 4.

24.3259.

)

l — 371808

TABLE 4

Comparison of Observations and Fitted Curves

Number of Ordinates Ordinates

Seeds per ; Observed of Normal of Type 1

Capsule Frequency urve Curve

9 1 2 .06

10 0 4 :2

11 0 8 .9

12 2 1.6 1.2

13 2 3.1 2.6

14 1 5.6 5.2

1 Biometrika, vol. 4, p. 173.

No. 479] VARIATIONCIN LOTUS

TABLE 4 (continued)

Number of Ordinates

Seeds per Observed of Normal

Capsule Frequency Curve

15 13 9.7

16 11 16.0

17°: 30 25.0

18 41 37.0

19 58 51.8

20 60 69.0

21 101 87.0

22 iH 104.1

23 113 118.1

24 114 127.0

25 107 129.6

26 137 125.3

27 120 115.0

28 101 100.0

29 90 » 82.5

30 ~ 62 64.5

31 45 47.9

32 34 33.7

33 21 22.5

34 13 14.2

35 11 8.5

36 7 4.9

37 2 2.6

38 1 1.3

39 1 it

Ordinates

of Type 1

Curve

9.5

16.2

ee a a oe OS

WrRAON TN SP OD w -I

[uw

GO (Q rm

[^d D Si

DO du o0o-1t20-10 09

m RN G9

D m UM

Of course to get absolute accuracy, areas instead of ordinates

should be compared with the observed frequencies, but inasmuch

as the number of groups is here large, the error made by comparing

ordinates will not be serious.

The frequency polygon and fitted curves are shown in Fig. 4.

The fit is seen to be excellent in the case of both the curves, but —

the slight superiority of the Type 1 curve is apparent. The dif-

ference, as has been pointed out above (p. 762), between this and

the normal curve is not significant. The greatest discrepancy

between the observations and the curves is in the region about the

mode. I am unable to account for the curious irregularity in the

THE AMERICAN NATURALIST [Vor. XL

764

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AONANdAUA

No. 479] VARIATION IN LOTUS 765:

observation polygon in this region except as a result of random

sampling. ,

The fact that this distribution approaches very closely to the

normal type is indicated by the value obtained for the theoretical

range of variation when a 'Type 1 curveis used. It will be recalled

that this type of curve has the range limited in both directions,

while the normal curve has an infinite range. Using the values.

of the moments given in Table 3, I find for the Type 1 curve: —

Total range — 60.8794

Lower limit of range — —3.9252

Up ~= —— | w DOMI .

It is clear that the theoretical range greatly overestimates the-

observed. Of course the start at —4 seeds appears at first sight

to be an absurdity, but it must be remembered that this value is

subject to a considerable probable error, and that it is possible to.

get as great an extension as this of the range of the theoretical

curve below zero as a result merely of random sampling. Further-

more it must be admitted that while the upper limit of the range

at 57 seeds seems very improbable, yet, for anything we know to:

the contrary, it is not impossible! In general it is clear from this

case that as the Type 1 curve approaches the normal its range

becomes greatly extended.

There is one further point regarding this material to which

attention should be called, namely, the bearing of the results on the

question of the distribution of fecundity. It is evident that the

number of seeds borne by a plant is the measure of its fecundity.

In considering data like those here presented the question at once

arises as to whether each different class of capsules contributes.

its proportionate share in the total number of seeds available for

the propagation of a succeeding generation. A moment's con-

sideration shows that this cannot be the case in Nelumbium. The

figures given in Table 5 demonstrate this. To avoid the possibility

of misunderstanding, the manner in which this table is formed may

‘Since writing the above I have seen some actual statistics of variation

in seed number in the lotus in which the upper limit of the observed range

is 42 seeds, showing a tendency in the direction predicted by the theoretical

curve.

766 THE AMERICAN NATURALIST [Vor. XL

be stated briefly. The figures in the second column were obtained

by multiplying the number of seeds in a given capsule by the fre-

quency with which that class of capsule occurred in the sample.

‘The third column gives the same data reduced to per mille pro-

portions.

TABLE 5

Total Number of Seeds borne by Capsules of Different Sizes

Capsule Class (Seeds Total Number of Seeds Per Mille Number of

e) borne in all Capsules Seeds borne in all Capsules

of Designated Class of Designated Class

9 9

10 0 0

11 0 0

12 24 0.68

13 26 0.74

14 14 0.40

15 195 5.56

16 176 5.02

17 510 14.54

18 738 21.04

19 1102- 31.42

20 1200 34.21

21 2121 60.47

22 2442 69.63

23 2599 74.10

24 2136 78.02

25 2675 76.27

26 3562 101.56

27 3240 92.38

28 2828 80.63

29 2610 74.42

30 53.03

31 1395 39.77

32 1088 31.02

33 693 19.76

34 442 12.60

35 385 10.98

36 252 7.19

37 74 2.41

38 38 1.08

39 39 1.11

Total 35,073 1000.00

No. 479] VARIATION IN LOTUS 767

From this table we see that, in round numbers, 1400 capsules

produce 35,000 seeds. Further, it is clear that the different classes

of capsules do not contribute in proportion to their frequency of

occurrence to the total seed number. Thus, for example, a ref-

erence to Table 1 shows that capsules with 21 seeds each and

capsules with 28 seeds each occur with equal frequency in our

sample. But obviously the latter will contribute more to the total

number of seeds. As a matter of fact the 28-seed capsules contri-

bute 81 per thousand of the total number of seeds, as against 60

per thousand of the 21-seed capsules. Taking the data as a whole

I find by a very simple calculation that:

(a) Capsules with fewer than the median number of seeds bear

altogether 15066.325 seeds, or 42.96 percent of the total number.

(6) Capsules with more than the median number of seeds bear

altogether 20006.675 seeds, or 57.04 percent of the total number.

In other words 50 percent of the capsules produce 57 percent of

the seeds, or, put in still another way, one half of the heads bears

14 percent more of the total number of seeds than does the other

half. This result is, of course, an obviously necessary arithmeti-

cal consequence of the symmetry of the capsule distribution, yet

it is a point which is frequently overlooked. A symmetrical dis-

tribution of the individuals of a population with respect to some

measure of fecundity does not mean that the contributions of these

individuals to the next generation even before selection will be

represented by a symmetrical distribution. ‘The very fact that the

original distribution is symmetrical necessitates the contrary

relation.

The results with reference to the proportionate contributions

of the different classes of heads to the total seed number show the

conditions before elimination begins. Many of the 35,000 seeds

were undoubtedly incapable of germination, and after germina-

tion many more would be eliminated before reaching maturity.

As to the distribution of the eliminating factors acting in the case

of the lotus we know nothing. What I wish to emphasize here is

that out of the total number of seeds before elimination begins,

57 percent are the product of one half of the parent heads and only

43 percent the product of the other half.

The results of this study may be summarized briefly as follows:

768 THE AMERICAN NATURALIST [Vor. XL

(1) In the variation in respect to number of seeds per capsule

Nelumbium luteum follows very closely the normal or Gaussian

law of the distribution of errors.

(2) Place constants are given for the designated character in

the form unit of Nelumbium growing in Sandusky Bay.

(3) From the fact that the frequency distribution of the capsules.

in respect to seed number is symmetrical about the mean it follows

that one half of the whole number of capsules bears 14 percent.

more of the total number of seeds available for a new generation

than does the other half of the capsules.

ZoÖLOGICAL LABORATORY

UNIVERSITY OF PENNSYLVANIA

PHILADELPHIA, Pa

THE CAUSES OF EXTINCTION OF MAMMALIA

HENRY FAIRFIELD OSBORN

In studying the past history’ of the Mammalia we find that in

some cases the causes of the extinction are as obscure as in other

cases they are obvious. I have thus been led to review the subject

very carefully, gathering opinions and observations from various

sources. I especially desire to arouse discussion and to receive

criticisms and suggestions which will be warmly welcomed.’

History or OPINION

We find that while the main trend of present inquiry as to the

external causes of extinction had been suggested by the middle of

the nineteenth century, subsequent discoveries and observations

furnish new and exact materials for induction both as to external

and internal causes.

Cuvier, Lyell, Darwin.—'The ‘cataclysmal’ views of Cuvier,’

of wholesale destructions brought about by sudden and great

geological changes, naturally gave way to the ‘uniformitarian’

views gradually developed from the time of Buffon to that of Dar-

win. The notions of the similarity of past and present causes.

of the survival of the fittest, of internal causes of variation, devel-

opment, and decline, gradually took their modern form. Whewell®

clearly sets forth the opinions which developed between 1796 and

1 Especially in connection with a monograph for the U. S. Geological Survey,

entitled “The Titanotheres," which has been in preparation since 1900. This

series of articles in the Naturalist will be embodied in somewhat modified

form in the monograph.

* Address, Professor Henry Fairfield Osborn, American Museum of Natural

History, New York.

3 Cuvier, George. Discours sur les révolutions de la surface du globe et sur

les changements qu'ils ont produits dans le regne animal. Paris, 1840, 1 vol.

in 8vo.

t Whewell, — History of the Inductive Sciences, vol. 3, 1837.

769

770 THE AMERICAN NATURALIST [Vor. XL.

1837. Charles Lyell' gave the note for modern methods of re-

search, greatly influenced Darwin, and er exaggerated uni-

formitarianism.

In this very problem of extinction, however, uniformitarianism

has a stout opponent in Henry H. Howarth. In his extremely

interesting work The Mammoth and the Flood (London, 1878) he

revives the theory of the destructive flood and marshals a vast

number of facts to its support. “These facts," he observes (p.

xvii), “‘I claim prove several conclusions. ‘They prove that a.

very great catastrophe or cataclysm occurred at the close of the

Mammoth period, by which that animal, with its companions,

were [!] overwhelmed over a very large part of the Earth's sur-

face. Secondly, that this catastrophe involved a very widespread

flood of water, which not only killed the animals but also buried

them under continuous beds of loam or gravel. ‘Thirdly, that the

same catastrophe was accompanied by a very great and sudden

change of climate in Siberia, by which the animals which had pre-

viously lived in fairly temperate conditions were frozen in their flesh

under ground and have remained frozen ever since."

The causes enumerated by Lyell in his later edition of the Prin--

ciples of Geology after the publication of Darwin's Voyage and

Origin are: (1) competition as affected chiefly by the introduction

and extension of new forms, (2) agency of insects, e. g., caterpillars,

ants, locusts, in favoring or checking increase of plants and thus.

affecting the food supply of animals, (3) intimate reciprocal rela-

tions of animals and plants in the delicate balance of food supply,

(4) disturbance of the equilibrium or balance of nature by the

introduction of new insects, plants, vertebrated animals, (5)

changes in physical geography affecting zoólogical and botanical

provinces by new land or water connections, facilitating introduc-

tion of new competing forms, (6) causes especially potent in island

life.

Referring to that subtle adjustment of the sum of all internal

and external causes called the balance of nature, Lyell? observed:

“Every new condition in the state of the organic or inorganic

1 Lyell, Charles. Principles x Geology, 187

?Lyell, Charles. Principles of Geology, ei 2, New York, 1872, pp. 455—

456.

No. 479] EXTINCTION OF MAMMALIA 771

creation, a new animal or plant, an additional snow-clad moun-

tain, any permanent change, however slight in comparison to the

whole, gives rise to a new order of things, and may make a material

change in regard to some one or more species. Yet a swarm of

locusts, or a frost of extreme intensity, or an epidemic disease,

may pass away without any great apparent derangement; no

species may be lost, and all may soon recover their former rela-

tive numbers, because the same scourges may have visited the

region again and again, at preceding periods. Every plant that

was incapable of resisting such a degree of cold, every animal

which was exposed to be entirely cut off by an epidemic or by

famine caused by the consumption of vegetation by the locusts,

may have perished already, so that the subsequent recurrence of

similar catastrophes is attended only by a temporary change.”

Even as a geologist Lyell was very cautious, certainly too

cautious, in estimating the destructive influence of geologic and

physiographic changes. In 1863 (Antiquity of Man,' p. 374), he

observed:

“It is probable that causes more general and powerful than the

agency of Man, alterations in climate, variations in the range of

many species of animals, vertebrate and invertebrate, and of

plants, geographical changes in the height, depth, and extent of

land and sea, some or all of these combined, have given rise, in a.

vast series of years, to the annihilation, not only of many large

mammalia, but to the disappearance of the Cyrena fluminalis,

once common in the rivers of Europe, and to the different range or

relative abundance of other shells which we find in the European

drifts.”

Charles Darwin? pursues a line of thought exactly prophetic to

that of Lyell in discussing the Pliocene and post-Pliocene ex-

tinction of the large mammals of South America. He dismisses

any catastrophic causes and in general attributes extinction to a

cessation of those world-wide conditions of life which were favor-

able to the larger quadrupeds in Europe, Asia, Australia, North and

1 Lyell, Charles. Geological Evidences of the Antiquity of Man, 2d ed.,

revised, 8vo, London, 1863, p. 374.

? Darwin, Charles. Journal of Researches. ...Voyage of H. M. S. Beagle,

8vo, 1834, pp. 169, 170.

712 THE AMERICAN NATURALIST [Vor. XL

South America. In South America and elsewhere (1) he does not

favor the extreme theory of the destructive influence of the Glacial

Epoch and he cites the supposed post-Glacial survival of Macrau-

chenia and Mastodon. “It could hardly have been a change of

temperature,” he observes (p. 170), “which at about the same

time destroyed the inhabitants of tropical, temperate, and arctic

latitudes on both sides of the globe.” (2) He dismisses the

possibility of extinction by man. (3) Also of an extended drought

in South America, calling attention to the Pampean horse as an

animal which could have survived a drought.

In seeking to establish a general law of extinction Darwin

makes the following propositions: (1) the natural increase of

animals is in geometrical ratio, while, (2) the food supply remains

constant, thus (3) any great increase in numbers is impossible and

must be checked by some means. (4) We are seldom able to

state the cause of this check beyond saying that it is determined by

some slight difference in climate, food, or the number of enemies.

(5) We are, therefore, driven to the conclusion that causes gen-

erally quite inappreciable by us determine whether a given species

shall be abundant or scanty in numbers. (6) Comparative rarity

is the plainest evidence of less favorable conditions of existence.

(7) Rarity frequently precedes extinction, and if the too rapid

increase of species, even the most favored, is steadily checked, why

should we feel such great astonishment at the rarity being carried

a step farther to extinction. .

These were Darwin’s earlier views expressed in The Voyage.

In The Origin of Species he discusses fully the checks to increase as

follows: (1) climate as directly unfavorable, (2) as indirectly

unfavorable by favoring other forms or by increasing the number of

certain competitors. (3) Unchecked increase frequently followed

by epidemics — possibly in part by facility of diffusion of parasites

amongst the crowded animals. (4) Finally, since a large stock

of individuals, relatively to the number of enemies, is absolutely

necessary for the preservation of a species a diminished number

would tend to extinction. (5) Any form (p. 133) which is repre-

sented by few individuals will run a good chance of utter extinction,

during great fluctuations in the nature of the seasons, or from a

‘temporary increase in the number of its enemies. (6) Diminution

No. 479] EXTINCTION OF MAMMALIA Vis

in number presents less opportunity for producing favorable vari-

ations — hence rare species will be less quickly modified or im-

proved within any given period.

Alfred Russell Wallace observes: ‘To discover how the extinct

species have from time to time been replaced by new ones down

to the very latest geological period, is the most difficult, and at

the same time the most interesting problem in the natural history

of the earth." Also: ‘‘ Whenever the physical or organic conditions

change to however small an extent, some corresponding change will

be produced in the flora and fauna, since, considering the severe

struggle for existence and the complex relations of the various

organisms, it is hardly possible that the change should not be

beneficial to some species and hurtful to others.” ?

The majority of these speculations of these great naturalists

have been abundantly confirmed. The opinions of many sub-

sequent writers on this subject may be stated under their proper

headings.

EXTERNAL CAUSES OF EXTINCTION

PuysicAL ENVIRONMENT. GEOLOGICAL AND PHYSIOGRAPHIC

HANGES

We may first consider those causes of extinction which originate

with changes in the environment.

Changes of Land Masses and their Connections

Changes of land masses caused by elevation or subsidence

operate indirectly through causing changes in all the physical

conditions of climate, moisture, or dessication, temperature, etc.;

also more directly in facilitating or cutting off migrations, in intro-

ducing new competition, ete.

Diminished or Contracted Land Areas.—'The stable continents,

North America and Africa, underwent slight fluctuations of land

area in Tertiary times as compared with the highly unstable conti-

nents of Europe, of Australia, and of the southern half of South

1 Wallace, Alfred R. Natural Selection, p. 14.

? Wallace, Alfred R. Darwinism, 1889, p. 115.

774 THE AMERICAN NATURALIST [Vor. XL

America. In Europe the varying coast lines, the insular condi-

tions, the archipelagic surfaces are to be more seriously studied

than they have been in connection with extinction, although it

must be stated at once that the main phenomena of extinction in

unstable Europe coincide with those in stable America.

Wallace discussed the extinction of the large Pliocene Austra-

lian mammals chiefly from this standpoint (see also p. 785). He

(Geog. Dist. Mam., 1876, vol. 1, pp. 158-159) attributed the

Australian extinction chiefly to the possible glacial conditions and

to the increased competition and struggle for existence caused

by the progressively contracted land area due to subsidence.

The substitution of insular for continental conditions by subsi-

dence has undoubtedly been a potent cause both of extermination

in certain localities and of the survival of very primitive forms

(Wallace), e. g., Monotremata and Marsupialia in Australia.

While the contraction of land areas may have resulted in general

extinction, this has not yet been demonstrated.

nsular Conditions.— On islands we observe local dwarfing

and extinction rather than the general extinction of a family or

order which is our real subject. Of island life, so thoroughly

studied by Wallace, it may be said at once that most of the causes

both of survival and extinction which prevail on continents are

intensified on islands. Wallace rightly attributes the survival of

the Monotremata and Marsupialia to the practically insular con-

dition of the Australian region. Lyell, Wallace, and others cite

many instances of profound and rapid modifications caused by

the introduction of new forms on islands.

PHYSICAL ENVIRONMENT. CHANGES OF CLIMATE

We have to consider temperature and moisture as brought about

by geologic and physiographic changes, and also as affected by

biotic changes or changes in the fauna and flora.

Increasing Cold

Influence of Secular Cold.— The effects of secular lowering of

temperature must be analyzed with some care. At first sight

No. 479] EXTINCTION OF MAMMALIA 775

the theory of extinction through the direct action of cold is very

simple, but it is found that some cases of extinction during the

Glacial Period, of the horse in North America for example, do not

admit of this explanation. It is more in accord with the facts to

say that the Glacial Period originated certain new conditions of

life which hastened extinction; these conditions relate to enforced

migration, to overcrowding, to feeding, reproduction, mating, re-

lations to enemies, deforestation, and other indirect results.

Protective Adaptation to Secular Cold.— Resistance to cold

depends upon (a) internal heat-producing power which is a pro-

gressive adaptation of the higher Mammalia, (b) the acquisition

of a warm external covering. ‘The-well known cases of adapta-

tion to extreme cold among the elephants (E. primigenius, woolly

mammoth), rhinoceroses (R. tichorhinus, woolly rhinoceros),

horses (E. przewalskii), and certain northern ruminants, such as

the camels and musk oxen, show that we must not assume that

cold was in all cases the sole or direct cause of extinction.

Glacial and Post-Glacial Extinction. — Wallace observes:

“....We have proof in both Europe and North America, that

just about the time these large animals were disappearing, all the

northern parts of these continents were wrapped in a mantle of ice;

and we have every reason to believe that the presence of this large

quantity of ice (known to have been thousands of feet if not some

miles in thickness) must have acted in various ways to have pro-

duced alterations of level of the ocean as well as vast local floods,

which would have combined with the excessive cold to destroy

animal life."* And again: “....We can therefore hardly fail to

be right in attributing the wonderful changes in animal and vege-

table life that have occurred in Europe and North America between

the Miocene period and the present day, in part at least, to the two

or more cold epochs that have probably intervened. ‘These

changes consist, first, in the extinction of a whole host of the higher

animal forms; and, secondly, in a complete change of types due

to extinction and emigration, leading to a much greater difference

between the vegetable and animal forms of the Eastern and

Western hemispheres than before existed.”

1 Geographical Distribution of Animals, vol. 2, p. 151.

? Wallace, A. R. Island Life, 1881, p. 117.

776 THE AMERICAN NATURALIST [Vor. XL

Certainly the most direct instance of a great extinction of quad-

rupeds contemporaneous with a secular change of climate is that

of the Glacial Period in the entire northern hemisphere. ‘The

close of the Pliocene or beginning of the Pleistocene found North

America peopled with the following kinds of great quadrupeds,

all of which disappeared during the Ice Age.

Artiodactyla Camelidze Camels

Llamas

Perissodactyla Equidee Horses

Tapiridee Tapirs

Proboscidea Mastodontinze Mastodons

; Elephantinze Elephants

Edentata Gravigrada Giant Sloths

Megalonyx

Megatherium

Paramylodon

Glyptodontia Glyptotherium

Numerical Diminution of Camelide.—'The Glacial Period was

heralded by increasingly severe winters and cold waves. The

observations of Prichard in Patagonia throw a light on the numeri-

cal diminution of the Camelidee.

“ Around the lake lay piled the skulls and bones of dead game,

guanaco (Lama huanachus) and a few huemules (Furcifer chilensis).

These animals come down to live on the lower ground and near

unfrozen water during the cold season, and there, when the weather

is particularly severe, they die in crowds. We saw their skeletons,

in one or two places literally heaped one upon the other” (Through

the Heart of Patagonia, 1902, p. 132). “Again we came upon a

second death-place of guanaco, which made a scene strange and

striking enough. ‘There cannot have been less than five hundred

lying there in positions forced and ungainly as the most ill-taken

snapshot photograph could produce. Their long necks were

outstretched, the rime of the weather upon their decaying hides,

and their bone-joints glistening through the wounds made by the

beaks of carrion-birds. ‘They had died during the severities of

the previous winter, and lay literally piled one upon another”

(op. cit., p. 189). “The meaning of this I gathered from

Mr. Ernest Cattle. He told me that in the winter of 1899 enor-

No. 479] EXTINCTION OF MAMMALIA “ees

mous numbers of guanaco sought Lake Argentino, and died of

starvation upon its shores. In the severities of winter they seek

drinking-places, where there are large masses of water likely to

be unfrozen. The few last winters in Patagonia have been so

severe as to work great havoc among the herds of guanaco”

(op. cu., p. 255).

Deforestation and Secular Cold.— After considering the condi-

tions in Alaska, Mr. A. G. Maddren' summarizes his conclusions

as follows: “I. That while remnants of the large Pleistocene

mammal herds may have survived down to the Recent period

and in some cases their direct descendants, as the musk-ox, to the

present, most of them became extinct in Alaska with the close of

the Pleistocene.

“TI. The most rational way of explaining this extinction of

animal life is by a gradual changing of the climate from more

temperate conditions permitting of a forest vegetation much farther

north than now, to the more severe climate of today, which sub-

duing the vegetation and thus reducing the food supply besides

directly discomforting the animals themselves, has left only those

forms capable of adapting themselves to the Recent conditions

surviving in these regions to the present.”

Influence of Cold and Snow on Food Supply and Choice of Food.

— The deaths of great numbers of animals from hunger or starva-

tion through the covering of food during the winter season under

heavy layers of snow are commonly observed among the large

herds of some of the domesticated horses and cattle on the Western

plains. In fact, it is most probable that during the glacial period

the great winter snow blankets covering the natural food rather

than the actual influence of the cold itself, was the chief cause of

extinction.

Under these conditions horses are driven to food, such as the

branches of willows, which is very deleterious to them. Under the

influence of hunger cattle and sheep also will feed eagerly and

indiscriminately on plants which may be injurious to them or to

their young, as recorded by Chestnut and others in the United

! Maddren, A. G. Smithsonian Exploration in Alaska in 1904, in Search

of Mammoth and other Fossil Remains." Smiths. Misc. Coll., vol. 49, p. 65.

778 THE AMERICAN NATURALIST [Vor. XL

States Agricultural Department. The indirect results of hunger

may be, therefore, quite as effective as actual starvation.

Animals vary greatly in adaptability to new conditions caused

by prolonged cold and heavy snowfall. Horses remove snow even

to depths of three or four feet and find food to carry them through

the winter, while cattle under the same conditions starve.

An interesting instance of the effects of a temporary lowering

of temperature in a subtropical region is that cited by Bangs of

the influence of an unusual cold wave in the habitat of one of the

Sirenia (Manatus manatus) in the rivers of Florida in the winter

of 1895. The author observed that an unusual cold wave cut

down all the leaves of the mangrove, a favorite food of the manatee

at certain seasons. This was followed by a marked numerical

diminution of the manatee."

Dangers of Numerical Diminution and Diminished Herds.—

While distinction must be drawn between actual extinction and a

temporary diminution in numbers caused, for example, by cold

waves, prolonged or repeated droughts, floods, epidemics, and

other unfavorable conditions of life, it is very important to observe,

as suggested by Darwin, that diminution in numbers may lead to

extinction in certain cases. For example, a herd of animals may

be reduced to the danger point in numbers where they can no

longer protect their young. Director Bell of the Canadian Geo-

logical Survey believes that the small herd of Woodland Bison of

British Columbia, now thoroughly protected by the government,

will be destroyed gradually through the killing of the calves by

wolves, the bulls not being sufficiently numerous to protect the

calves.

Diminished Herds and Inbreeding.— Diminished herds in re-

stricted regions may also disappear through too close inbreeding.

On this familiar subject see Gerrit S. Miller’s? paper “Fate of

the European Bison Herd,” in which the author shows the pos-

sibly fatal influence of inbreeding on diminished herds, although

it must be pointed out that the animals are protected and are thus

living under unnatural conditions.

1 Mr. C. H. Townsend, from observations in the New York Aquarium, is

inclined to attribute this diminution to the respiration of the frosty air.

? Miller, Gerrit S., Jr. “The Fate of the European Bison Herd.” Science,

n. s., vol. 4, no. 99, Nov. 20, 1896, pp. 744-745.

No. 479] EXTINCTION OF MAMMALIA 779

In a paper entitled “Das allmähliche Aussterben des Wisents

(Bison bonasus Linn.) im Forste von Bjelowjesha",' Mr. Eugen

Biichner gives a detailed history of the bison herd in the Bie-

loviejsha (or Bialowitza) forest, Province of Grodno, in Lithuania,

Russia, during the present century. “A careful study of the

breeding habits of the bison in the Bieloviejsha forest and else-

where leaves no room for doubt that the present slow rate of

reproduction is an abnormal condition, and that to it is due the

rapid approach of the extinction which is the certain fate of the

herd under consideration. ‘This diminished fertility the author

regards as a stigma of degeneration caused by in-breeding....

Another indication of the degenerate condition of the Bieloviejsha

herd is seen in the great excess of bulls, which probably outnumber

the cows two to one. This is doubtless a result of in-breeding,

for Düsing (Jen. Zeits. f. Naturw., Bd. xvii, p. 827, 1884) has

shown that close in-breeding, like a reduced condition of nutrition,

is favorable to the production of an excess of males....In con-

clusion, the author considers that his studies of the history of the

Bieloviejsha bison leave scarcely room for doubt that in-breeding

is the cause of the final extinction of most large mammals. In-

breeding must begin and lead gradually but certainly to the ex-

tinction of a species when it, through any cause, has become so

reduced in numbers as to be separated into isolated colonies."

Influence of Cold during the Reproduction Period. — Exceptional

cold waves or unusually prolonged cold seasons may cause a

temporary loss of food supply or cause the death of the young,

which in northern latitudes are usually born in spring. The

diminution or loss of young from this cause might act as the first

of a series of destructive effects of a progressive secular change.

These may be summarized as follows from actual zoölogical

observations" among the Cervidz: (a) disturbed conditions dur-

ing the conjugation (pairing, mating, rutting) period; (b) enfeebled

(through hunger) condition of females during parturition period;

1 Büchner, Eugen. Mém. Acad. Impér. des Sci. de St. Pétersbourg, vol. 3,

no. 2, 1895, p. 1-30.

? Communicated by Mr. Madison Grant, Secretary of the Zodlogical Society

of New York.

‘

780 THE AMERICAN NATURALIST [Vor. XL

wet and sleet at time of birth; (d) bulls unable to protect herds;

(e) cows unable to protect young from Carnivora through starved

condition, or abandoning them when attacked by wolves; (f)

enfeebled and unprotected condition of quadrupeds favorable to

increased food supply and consequent multiplication of cursorial

and other Carnivora, especially Canidz and Felidee.

These zoölogical observations are to a certain extent borne out

in paleontology by Leith Adams’ (British Fossil Elephants, 1879,

part 2, p. 98) observations of the exceptionally large number of

milk teeth of elephants found in certain Pleistocene deposits,

which appears to indicate a high mortality of the young.

Temperature Control of Fertility and Reproduction.— Merriam*

has directed attention to one of the physiological effects of a lower-

ing of temperature, namely, its influence upon diminished or

increased fertility and the rate of reproduction in what he has.

called the ‘law of temperature control’. This he has stated as

follows: temperature by controlling reproduction predetermines the

possibilities of distribution; it fixes the limits beyond which species

cannot pass; it defines broad transcontinental barriers within

which certain forms may thrive if other conditions permit, but

outside of which they cannot exist, be the other conditions never

so favorable, (because the sexes are not fertile).

(1) Temperature. In discussing how species are checked in

their efforts to overrun the earth Merriam points out that more

important than geographic barriers are the climatic barriers (as

observed by Humboldt), and of these that temperature is more

important than humidity. First, in 1892, this author attempted

to show (Proc. Biol. Soc. Washington, vol. 7, April, 1892, pp.

45, 46) that the distribution of terrestrial animals is governed less

by the yearly isotherm or mean annual temperature than by the

total rather than the mean temperature during the period of repro-

ductive activity and of growth (adolescence). This reproductive

period in the tropics extends over many months or nearly the whole

year, and within the Arctic Circle and summits of high mountains:

is of two months or less duration. Later, in 1894, results which

‘Merriam, C. Hart. “Laws of Temperature Control of the Geographie

Distribution of Terrestrial Animals and Plants.” Nat. Geogr. Mag., vol. 6,

Dec. 29, 1894.

No. 479] EXTINCTION OF MAMMALIA 781

Merriam obtained from extensive comparison of temperatures and

distribution justified the belief that animals and plants (Lower

Austral and tropical types coming from the South) are restricted

in northward distribution by the total quantity of heat during the

season of development and reproduction. Conversely animals and

plants (Upper Austral, Transition, and Boreal types coming from

the North) are restricted in southward distribution by the mean

temperature of a brief period covering the hottest part of the year.

Thus in the Transition Zone, Boreal and Austral types mingle in

the equable climate of the Pacific coast of California while they

are sharply separated by the inequable extremes of cold and heat

of the interior continental plateau.

(2) Humidity, observes Merriam, is a less potent factor than

temperature in limiting the distribution of the Mammalia of North

America. (a) Many genera adapted to certain restrictions of

temperature zones range east and west completely across the

American continent inhabiting alike the humid and arid sub-

divisions but no genus adapted to certain restrictions of humidity

ranges north and south across the temperature zones. (b) 'Thus

humidity governs the details of distribution of a few species of

mammals within the temperature zones.

Lowering of Temperature and Diminished Fertility as a Cause of

Extinction.— Since the favorable influence of high mean tem-

perature on fertility and reproduction is well illustrated in the

reproductive organs of birds and in the early age of reproduction

and increased fertility of the human species toward the equator,

and since there exist these low-temperature barriers to reproduc-

tion, it is highly probable that a secular lowering of temperature

may have repeatedly been a cause of extinction in the earth's.

history; that certain mammals may have resisted exposure to

cold or discovered new forms of food and yet suffered extinction

through the subtle inhibition of fertility and reproduction.

Increasing Moisture

Influences of Increased. Rain Supply.— Besides the changes in

1 This would not be true of Africa, of Central America, or other tropical.

countries where certain insect and disease barriers exist which are favored.

by moisture.

782 THE AMERICAN NATURALIST [Vor. XL

plant food which are brought about by diminished moisture, as

indicated below, there are the effects of increased moisture which

may be equally if not more important. Dry or moderately dry

conditions, provided they are not too extreme, are generally more

favorable to quadrupeds than moist conditions. The plains and

forest regions most densely populated with quadruped life, such

as those of the African plateau, are regions of moderate rainfall

and even of prolonged summer droughts. The regions least

densely populated are regions of heavy rainfall and most dense

forests and vegetation, such as those of the equatorial belt of

South America or the Congo region of Africa. We observe that:

(1) Increased rainfall may diminish the supply of harder grasses

to which certain quadrupeds have become thoroughly adapted.

(2) Increased rainfall may introduce new poisonous or dele-

terious plants (see p. 790).

(3) It may be the means of introducing new insect and other

pests and new insect barriers.

(4) It may be the means of introducing new protozoan diseases,

‚and new insect carriers of diseases.

(5) It may be the means of erecting new forest barriers or new

forest migration tracts for certain Carnivora. It follows that

periods of secular increasing moisture such as the early Pleistocene

of the northern hemisphere is supposed to have been, may have

been very unfavorable to certain large quadrupeds, even prior

to the advent of extreme cold.

Insect Barriers and Moisture.—It is a matter of universal

observation that in tick- or insect-infested countries, generally,

dry seasons result in the reduction, moist seasons in the increase

of diseases. Dry localities are favorable; moist localities are

unfavorable.

Thus A. E. Shipley observes of the tse-tse fly, in his interesting

‚address' that its “northern limit corresponds with a line drawn

from the Gambia, its southern limit is about on a level with the

northern limit of Zululand. Most writers agree that the tse-tse

is not found in the open veldt, that it must have cover. Warm,

moist, steamy hollows, containing water and clothed with forest

growth are the haunts chosen.” *

‘Shipley, Arthur E. “Insects as Carriers of Disease." Nature, vol. 73,

‘no. 1888, Jan. 4, 1906, pp. 235-238.

No. 479] EXTINCTION OF MAMMALIA 783

Decreasing Moisture. Secular Desiccation

Secular desiccation has been the fate of portions of three great

continents, and on each continent we observe a general concomi-

tant modification and extinction of certain kinds of quadrupeds.

‘The great regions of the world where decreasing moisture has

introduced a series of changes ending in the extinction of a great

number of quadrupeds are:

(1) North America, Western Plains Region, Arid Plateau and

Mountain Region beginning in Oligocene times.

(2) South America, Patagonia and Pampean Region, beginning

in late Pliocene times.

(3) North Central Africa, the Fayüm district beginning in

Oligocene times.

(4) Central Australia, beginning in Pleistocene times.

The writings of American paleontologists, also of Stirling, of

Andrews, and of Ameghino, describe faunz adapted to much

moister conditions than those which prevail at present. We

observe that decreasing moisture:

(1) Changes the character of the food supply. Diminution of

softer and more succulent vegetation, increase of harder and more

resistant vegetation.

(2) Increases length and severity of the dry season.

(3) Removes forest barriers and admits new competitors.

(4) Reduces the water supply and eliminates animals incapable

of traveling long distances for food and water.

(5) Favors grazing quadrupeds and eliminates browsing and

forest-living quadrupeds.

Prolonged or increasing droughts entirely disturb the balance

of nature; they compel migrations; they expose quadrupeds to

Carnivora by driving them to restricted water pools. ‘They favor

quadrupeds able to dispense with a daily supply of water.

Secular Desiccation and Vegetation.— The indirect influences

of secular changes of climate on quadrupeds are apparently quite

as important factors in extinction as the direct, namely, changes

in vegetation due to diminution of moisture, which render certain

types of quadrupeds which were perfectly adapted to one kind of

784 THE AMERICAN NATURALIST [Vor. XL

plant food, largely or wholly inadapted to the new or altered kinds

of food. This we shall show was probably the most potent factor

in the extinction of the Titanotheres, of the Chalicotheres, in fact

of all the quadrupeds with short-crowned molar teeth, adapted to

browsing habits.

The correlation between an initial change of climate and the

consequent diminution of the softer kinds of vegetable food and

increase of the harder kinds, such as grasses, followed by the extinc-

tion of a very large number of Herbivora, was first thoroughly

worked out in an epoch-making memoir of Waldemar Kowalevsky

in 1873.

Droughts and Numerical Diminution.— Darwin’ describes

the devastating effects of the great drought in the Pampas between

1827 and 1830 in which great numbers of birds, wild animals,

cattle, and horses, perished from want of food and water. The

cattle perished by thousands on the muddy banks of the Parana

River. Similarly Azara describes the horses perishing in large

numbers in the marshes.

Increasingly prolonged summer droughts were diametrini of

the late Miocene and Pliocene of Europe, and we are beginning

to accumulate evidence that the same conditions prevailed in

North America.

Influence of Droughts in Central Ajrica.— The influence of the

gradual decrease of moisture in a country is clearly illustrated

in the conditions which prevail in the African continent to-day, as

observed by such writers as Gregory,’ Foa, and Schillings. Thirst,

like hunger, first drives quadrupeds to take extreme risks, which

they would absolutely avoid during natural conditions. The

drinking-places or water-pools during long seasons of drought

become fewer in number and more widely separated, and large

animals driven to them by thirst are more readily attacked and

killed by Carnivora. The pools become separated by distances.

of thirty and forty miles, thus necessitating long excursions to and

from the various feeding places, in which the quadrupeds are

‘Darwin, Chas. Journal....Voyage of H. M. S. Beagle around the World,

p. 128-130.

*Gregory. The Great Rift Valley. ...8vo. London, 1896.

No. 479] EXTINCTION OF MAMMALIA 785

again exposed to attack. Finally some of the pools dry up entirely

and, as observed by Gregory, (p. 268): “Here and there around

a water hole we found acres of ground white with the bones of

rhinoceroses and zebra, gazelle and antelope, jackal and hyena

....all the bones were there fresh and ungnawed....” These

animals, which had not migrated, had “crowded around the

dwindling pools and fought for the last drops of water.”

Such perishing of animals in great numbers -from thirst would

bring about the condition of diminished herds spoken of above as

the final cause of extinction through inability to protect the young.

Alkali and Salt Deposits.— One effect of increasing desiccation

is the increased number of alkali lakes, licks, and springs, and

other localities of salt deposits. Alkali is much sought by certain

wild animals as a substitute for salt. Western stock-raisers dis-

agree as to the effects of alkali upon sheep and cattle, some believ-

ing that it cannot take the place of salt. Chestnut (1901, p. 20)

notes that alkali may possibly predispose to the ‘loco habit,’ the

eating of a narcotic weed (see p. 791). When domesticated ani-

mals are not salted regularly they soon discover localities where

large quantities of alkali are found in the soil and visit such places

frequently for the purpose of eating this alkali soil (Chestnut, 1901,

p. 87).?

Desiccation and Extinction in Central Australia.— Wallace’s

Opinion as to Australian extinction has been cited more with refer-

ence to the effect of Glacial-Epoch conditions and continental con-

traction in general than as to the special causes of extinction in

Australia.

More recent research as set forth by the geologist Professor

Tate,’ the zoölogists Hedley? and Baldwin Spencer, show that in

Pliocene times heavy rainfall or pluvial conditions, great inland

1 Chestnut, V. K., and Wilcox, E. V. “The Stock-poisoning Plants of

Montana: A Preliminary Report." U. S. Dept. of Agric., Div. of Botany,

bull. 26, 1901.

? *On the Influence of Physiographie Changes in the Distribution of Life

in Australia." Austr. Ass. Adv. Sci., vol. 1, pp. 312-325, 1889. Quoted by

Baldwin Spencer. Through Larapinta Land; A Narrative of the Horn Expedi-

tion to Central Australia, Part 1, p. 159, 1896.

? “The Faunal Regions of Australia." Austr. Ass. Adv. Sci. Adelaide, 1893.

786 THE AMERICAN NATURALIST [Von XL

seas or freshwater lakes (first surmised by Stuart) favored the

development of large marsupials. Conversely the rise of an

eastern coastal range was followed by diminished rain supply and

progressive desiccation of the interior region.

Spencer observes:' “ The larger forms now extinct, such as

species of Diprotodon, Nototherium, Phascolonus, Macropus,

Protemnodon, etc., reached their greatest development in Pliocene

times and were characteristic of the eastern interior, spreading

southward round the western end of the Dividing Range into

Victoria. ‘They do not seem to have reached the eastern coastal

district... ... In Post-Pliocene times, with the increasing desicca-

tion of the whole central area they became extinct, though this

extinction cannot be attributed wholly to the drying up of the land,

because in certain parts, such as Western Victoria, to which they

reached, the state of desiccation did not supervene; but at the

same time it may perhaps be justly argued that the desiccation

of the vast area of the interior was the largest factor in their extinc-

tion." ;

The discovery (1892) of the great Lake Callabonna bone deposit

in the interior of South Australia abundantly confirms the ‘des-

iccation’ theory. Dr. E. C. Stirling? describes this remarkable.

deposit as follows: —

“ There is, however, compensation for the unpromising physical

features of Lake Callabonna in the fact that its bed proves to be a.

veritable necropolis of gigantic extinct marsupials and birds which

have apparently died where they lie, literally, in hundreds. The

facts that the bones of individuals are often unbroken, close to-

gether and, frequently, in their proper relative positions (vide

pl. A, fig. 3), the attitude of many of the bodies and the character

of the matrix in which they are embedded, negative any theory

that they have been carried thither by floods. The probability

is, rather, that they met their death by being entombed in the

effort to reach food or water, just as even now happens in dry

1 Spencer, Baldwin. Report of the Horn Expedition to Central Australia.

Summary oj the Zoological, Botanical and Geological Results oj the Expedition,

1896, p. 183.

? Stirling, E. C. “Fossil Remains of Lake Callabonna." Mem. Roy. Soc.

of South Australia, vol. 1, pt. 2, pp. ii-iii.

No. 479] EXTINCTION OF MAMMALIA 187

seasons, to hundreds of cattle which, exhausted by thirst and

starvation, are unable to extricate themselves from the boggy

places that they have entered in pursuit either of water or of the

little green herbage due to its presence. The accumulation of

so many bodies in one locality points to the fact of their assem-

blage around one of the last remaining oases in the region of

desiccation which succeeded an antecedent condition of plenteous

rains and abundant waters. An identical explanation has been

suggested by Mr. Daintree * in his ‘Notes on the Geology of the

Colony of Queensland.’”’

Livinc ENVIRONMENT. PLANT LIFE

Under climate we have considered the relations of cold, heat,

moisture, and desiccation to hunger, thirst, the feeding and migrat-

ing habits of animals. We may now look at the food supply of

the Herbivora in relation only to unusual conditions of life.

Forestation, Deforestation, and Reforestation.— Forests furnish

the necessary conditions of life of certain quadrupeds, especially

of the browsers and of the Proboscidia. Among Artiodactyla.

the deer, among Perissodactyla the tapirs are typical forest animals.

Conditions, therefore, which cause deforestation would become

a means of extinction; such conditions are (a) intense cold and

heavy snow capping, (b) intense dryness, (c) destruction of young

trees by the smaller browsing animals. It is probable that the

interior of Australia and the Pampean region of South America

were in Pliocene and early Pleistocene times partially covered

with forests. It is certain that the Holarctic region or circum-

polar belt was forested in the early Pleistocene. Our western

arid region was extensively forested at one period. Several of

the smaller islands of the Mediterranean have been deforested.

Reforestation would confine and limit the desert and plains types.

Progressive moisture and reforestation would be very unfavorable

to the horse (see Morris, 1895, p. 261). Thus both migration

barriers and migration tracts are formed by forests.

! Quart. Journ. Geol. Soc., vol. 28, 1872, p. 275.

788 THE AMERICAN NATURALIST [Vor. XL

A New or Altered Food Supply

Poisonous Plants.— Plants which are fatal to some Herbivora

are innocuous to others. Linneus in his Tour in Scania tells

us, as cited by Lyell * “that goats were turned into an island which

abounded with the Agrostis arundinacea, where they perished

by famine; but horses which followed them grew fat on the same

plant. The goat, also, he says, thrives on the meadow-sweet and

water-hemlock, plants which are injurious to cattle.” ?

We must be extremely cautious not to substitute artificial con-

ditions or those brought about by the agency of man for purely

natural conditions. In speaking of the deaths caused by the

twenty-five species of stock-poisoning plants found in Montana,

Chestnut * observes: “But all these causes operate much less

effectively against buffaloes and other ruminants in the wild state

for, in the first place, being bred there under perfectly natural

conditions, and being abundantly able to roam over long distances

in search for food and water, they naturally reject all but the best

and most wholesome diet. Then in the winter they migrate to

the south, where the conditions for their existence were more

favorable. . . . Besides, it would require a large quantity of any

of the common poisonous plants to kill an animal of such size.”

Observations in South Africa‘ give similar results. The

‘chinkerinchee’ plant (Ornithogalum) is poisonous to horses,

and one of the ragworts (Senecio) is an irritant causing cirrhosis

of the liver in cattle and horses. Other plants which give trouble

are tulps (species of Mora). The losses are chiefly among

cattle not accustomed to the country, or amongst very hungry

trek cattle.

It is true, first, that animals generally but not invariably learn

to avoid poisonous plants, second, that they become more or less

immune to their deleterious effects, third, that often it is solely

! Principles of NS vol. 2, p. 440, 1872.

? Ibid., vol. 7,

* “Some u Plants of the Northern Stock Ranges.” Yearbook

Dept. Agriculture for 1900, Washington, pp. 308-309.

* Kindly communicated by Charles P. Lounsbury, of the Department of

Agriculture, Cape of Good Hope. See Agricultural Journal, February, 1906.

No. 479] EXTINCTION OF MAMMALIA 789

the influence of hunger which drives them to eat poisonous plants.

‘This justifies the consideration of plants under unusual conditions

of life among the possible causes of extinction. The presence

of molds and smuts which appear on the Graminese, the introduc-

tion and spread of certain narcotic plants, the influence of ergot

in causing diseases of the hoof, the relation of poisonous plants

to increased or diminished rainfall, the introduction of certain

poisonous plants which while not injuring the parent affect and

frequently kill the suckling young may be considered. Lambs

are frequently killed by sucking milk from animals which had fed

on the death camas, Zygadenus venenosus.'

Dangers Heightened by Harsh or Unusual Conditions of Life

Poisonous plants are widely distributed. Under the unnatural

conditions of extreme cold, drought, enforced migration, starvation,

etc., it is not impossible that they may have exerted some influence

especially on diminishing herds. ‘The following observations are

chiefly brought together from the papers of Dr. V. K. Chestnut of

the U. S. Agricultural Bureau. This author states in a letter

dated July 9, 1902: “So far as my observations have extended

the chief circumstance leading to death from poisonous plants

is an irregularity of the food supply caused by more or less unusual

conditions. It does not seem reasonable to suppose that wild

animals are frequently poisoned in their native grazing grounds.

Sudden disasters, however, might drive them from their feeding

grounds into pastures quite unfamiliar to them, where they would

undoubtedly be more or less at a loss to distinguish between

poisonous and non-poisonous plants."

The following observations (a, b, c) apply to domesticated Her-

bivora.

(a) Varying Effects of Wet and Dry Months.— Chestnut (“ Stock-

Poisoning Plants of Montana" 1901, p. 19) observes that the

majority of plants known to be especially poisonous during the

wet months are so shriveled and dry in the dry months as to be

1 Chestnut, V. K., and Wilcox, E. V. Stock Poisoning Plants of Montana.

p. 61.

790 ` THE AMERICAN NATURALIST [Vor. XL

absolutely unpalatable. Sheep owners have accordingly found

mountain ranges which are extremely dangerous for sheep during

the wet months of early summer, quite safe during the months

from July to September inclusive. Similarly, during the wet

season and when feeding immediately after heavy rainstorms

domesticated animals are more apt to pull up the roots of plants

than when the ground is dry (Chestnut, 1901, p. 26), and, as is

well known, in the case of many poisonous plants it is the roots.

which chiefly contain the active principle.

(b) Fatal Effects of Snowstorms.— After heavy snowstorms.

when the grass is covered by snow it often happens that only the

taller species of plants are exposed (Chestnut, 1901, p. 27). In

such cases the poisonous larkspurs (Delphinium glaucum) are

greedily eaten by cattle, which would otherwise avoid these plants.

This tendency is increased by the fact that ruminants do not feel

at ease so long as the stomach is not full and.are inclined to eat

anything in sight after a snowfall. In seasons of drought certain

poisonous leguminous plants remain green and tempting after

the grasses have become thoroughly dried. Under these conditions

cattle on the range are known to take the loco and lupin (Chest-

nut, 1901, p. 29).

1901, p. 21) among domesticated animals that when feeding quietly

. on the range they exercise considerable choice in the selection of

forage plants, but when being driven six or eight miles a day they

are frequently forced by hunger to bite off almost all kinds of

plants which grow along their course. Enforced migration among

wild animals might similarly cause them to become less fastidious

about food.

Dangerous Plants Favored by Moisture

Poisonous Plants of Montana.— The chief poisonous plants of

the Montana stock ranges (Chestnut, 1901) are: the death camas

(Zygadenus), favored by moderate moisture and taken by sheep;

the “tall larkspur” (Delphinium glaucum), favored by moderate

moisture, taken by cattle; the “purple larkspur" (D. bicolor),

taken by sheep; the water hemlock (Cicuta), found along water

No. 479] EXTINCTION OF MAMMALIA 791

courses, taken by cattle and sheep; the white loco (Aragallus),

taken by horses, sheep, and cattle. Lupines (Lupinus) in cer-

tain stages of growth are poisonous to sheep. Ergot (Claviceps

purpurea), occurs in Montana on a variety of grasses, and is occa-

sionally poisonous to horses and cattle, producing a disease of

the limbs. On a large ranch of Wyoming, ergot is reported

(Walter Granger, letter, 1904) to have appeared as a result of

irrigation rendering a large tract fatal to horses and cattle by

causing a disease of the hoofs.

A leguminous plant of Egypt, Lotus arabicus, recently investi-

gated by Dunstan and Henry,’ as a growing plant, is quite poison-

ous to horses, sheep, and goats. Its seeds when ripe are commonly

used as fodder. It contains a glucecoid termed 'lotusin,' which

is poisonous when taken into the stomach (Chestnut, 1902).

Narcotic Plants.— Among narcotic plants ‘loco weeds’ are the

most interesting. ‘Loco’ is a Spanish word meaning mad or

crazy, and is applied in northern Mexico and southern United

States to certain plants which so affect the brain of animals as to

give them all the symptoms of brain disease. As described in the

important papers of Chestnut’ the weeds called ‘loco’ belong to

genera of the bean family. ‘‘ For many years," this writer observes,

“a disease called loco, affecting cattle, horses, and sheep, has been

generally known to the stockmen of the western ranges. This

disease has most commonly been attributed to the action of cer-

tain plants, more rarely to that of alkali. Several species of plants

have been suspected of producing the loco condition in animals

and have been called loco plants or loco weeds and also crazy

weeds from the nature of the disease. Nearly all of the plants

which have been considered loco weeds belong to two genera of

the pea family, Astragalus and Aragallus. These genera are

represented by numerous species on the Western stock ranges... .

(p. 87)....From a general description given of the loco disease

it is apparent that this condition might very justly be termed a

perverted appetite....The horse and the sheep are the animals

1 “ Problems in the Chemistry and Toxicology of Plant Substances." Science,

n. s., vol. 15, no. 391, June 27, 1902, pp. 1016-1028.

? Chestnut, V. K. “Preliminary Catalogue of Plants Poisonous to Stock.’”

Ann. Rep. Bur. of Anim. Indus., 1898, pp. 403, 404.

792 THE AMERICAN NATURALIST [Vor. XL

which are most frequently affected by loco disease. Cattle occa-

sionally acquire the loco habit, but the cases are comparatively

rare. In certain parts of Montana the habit became so wide-

spread among horses that the raising of them was abandoned until

the locoed animals were disposed of and other horses which had

not the loco habit had been imported" (p. 89). “During the

progress of field work in Montana in 1900, about 650 locoed sheep

and 150 locoed horses were seen "* (p. 90).

Mechanically Dangerous Plants.—'There occur in Montana

occasional losses of stock from plants acting mechanically. For

example, the sharp-barbed awns of the porcupine grass (Stipa

spartea) and squirreltail (Hordeum jubatum) when the plants are

maturing, separate, and entering the mouth, throat, eyes, and ears

of stock, affect the tissues and give rise to ulcers which cause intense

suffering and necessitate killing.’ Similarly the corn-stalk disease

is sometimes attributed to malnutrition or impaction of the

alimentary canal.

In this connection may also be cited an observation recorded

by Thistleton-Dyer? which happens to bear upon the life of goats.

“The introduction of the sweet briar into New South Wales, Austra-

lia, in many parts of which it is naturalized, affords a striking

illustration of the mode in which the balance of nature may be

disturbed in a wholly unforeseen way....The fruit of the sweet

briar (Rosa rubiginosa) consists of a fleshy receptacle lined with

silky hairs which contains the seed-like carpels. .... The hairy

linings of the fruit caused the death of a number of goats by form-

ing hairy calculi, which mechanically occluded the lumen of the

bowels. These goats were put on the land with the idea that they

would eat down the briars and ultimately eradicate them, but

the briars came out best and eradicated the goats. The cattle

running on the land are also very fond of the briar berries, and

1 Chestnut, V. K., and Wilcox, E. V. “The Stock-Poisoning Plants of

Montana: A Preliminary Report.” U. S. Dept. of Agric. 1901, bull. 26, pp.

87-90.

? Chestnut, V. K. “The Stock-Poisoning Plants of Montana. A Prelimi-

nary Report." U.S. Dept. of Agric., 1901, bull. 26, pp. 50-51.

8 “The Sweet Briar as a Goat-Exterminator.” Nature, vol. 66, no. 1697,

May 8, 1902, p. 31.

No. 479] EXTINCTION OF MAMMALIA 793

from time to time one will die, and on post mortem [examination]

no pathological changes can be found in any of the orgaus, nor do

the hairy calculi appear in them, although their various stomachs

are one mass of the briar seeds."

Livia ENVIRONMENT. Insect LIFE

The features of physical environment such as moisture and

desiccation, forestation and deforestation, heat and cold, cannot be

considered by themselves or solely in relation to plant life but in

relation to the insect life which they condition and which indirectly

becomes the barriers and even the exterminators of mammalian

life.

We may first consider the influence of the introduction into

habitual feeding grounds of various forms of insect life which

render these grounds practically uninhabitable and either kill or

drive the animals out. ‘Thus Wallace’ observes: “The next case

I will give in Mr. Darwin’s own words: ‘In several parts of the

world insects determine the existence of cattle. Perhaps Para-

guay offers the most curious instance of this; for here neither

cattle nor horses nor dogs have ever run wild, though they swarm

southward and northward in a feral state; and Azara and Rengger

have shown that this is caused by the greater numbers, in Para-

guay, of a certain fly which lays its eggs in the navels of these ani-

mals when first born. ‘The increase of these flies, numerous as

they are, must be habitually checked by some means, probably by

other parasitic insects. Hence, if certain insectivorous birds were

to decrease in Paraguay, the parasitic insects would probably

increase; and this would lessen the number of the navel-fre-

quenting flies —then cattle and horses would become feral, and

this would greatly alter (as indeed I have observed in parts of

South America) the vegetation: this again would largely affect

the insects, and this, as we have just seen in Staffordshire, the

insectivorous birds, and so onward in ever-increasing circles of

complexity....’”

The two-horned rhinoceros (R. bicornis) of Africa as well as

1 Wallace, Alfred R. Darwinism, 1889, p. 19.

794 THE AMERICAN NATURALIST [Vor. XL

some members of the antelope family are well known to be pro-

tected from insects by birds (see Millais’s Breath of the Veldt, and

other works). Anyone who has watched the sufferings of cattle

and horses from flies knows that insects may become an important

factor in expelling animals from a certain country to which they

are naturally adapted by their tooth and foot structure.

Ticks.— Ticks, even when nen-infection-bearing, form absolute

and effective barriers to the introduction of quadrupeds into certain

regions. In certain forested portions of South and Central America

they endanger human life. In certain regions of Africa ticks are

practically fatal to horses; as observed by Dr. D. G. Elliot thou-

sands of ticks would sometimes gather on a horse as a result of a

single night’s grazing. ‘The mane especially serves to collect these

pests. Thus the falling mane of the northern horse is distinctly

disadvantageous as compared with the upright manes of the asses

and zebras. ‘Ticks are capable of driving certain types of animals

entirely out of a country and of indirectly causing certain modifi-

cations of the hair and epidermis.

Frontal Air Sinuses.— Larvee invading the frontal sinus of the

skull are not to be left out of account among the possible causes

of elimination. An old trapper and close observer in British

Columbia, Mr. Charles Smith, informs me that both the wild

sheep of the region (Ovis montana) and the wapiti (Cervus cana-

densis) are seriously affected and sometimes killed by inflammation

caused by these larvee. The over-crowded caribou of Labrador

and Newfoundland suffer from a fly which lays its eggs in the

nostril passages.

In certain of the Eocene Titanotheres, in Dolichorhinus espe-

cially, the frontal air sinuses communicate with sinuses extending

completely back to the occiput. The invasion of such sinuses

by larvee would undoubtedly be very harmful if not fatal.

Insects and the Food Supply.— The periodic devastations of

certain insects especially those caused by locusts as cited by Lyell

in Europe, Arabia, India, and Northern Africa, are quite sufh-

cient to cause the extinction of certain species. As Lyell concludes :'

“The occurrence of such events at certain intervals, in hot countries,

1 Lyell, C. Principles of Geology, vol. 2, 1872, p. 445.

No. 479] EXTINCTION OF MAMMALIA 795

like the severe winters and damp summers returning after a series

of years in the temperate zone, may affect the proportional numbers

of almost all classes of animals and plants, and probably prove

fatal to the existence of many which would otherwise thrive there;

while, on the contrary, the same occurrences can scarcely fail to

be favourable to certain species which, if deprived of such aid,

might not maintain their ground.”

(To be continued)

A PRELIMINARY STUDY OF THE FINER STRUCTURE

OF ARCELLA

JOSEPH A. CUSHMAN AND WILLIAM P. HENDERSON

Tis study of Arcella is based upon two species, Arcella vulgaris

Ehrenberg and Arcella mitrata Leidy. The structure of the test

in Arcella is usually described as given by Leidy (‘Fresh-water

Rhizopods of North America,” U. S. Geol. Surv. Territories, vol.

12, p. 167): “Composed of a more or less translucent or trans-

parent chitinoid membrane, with a minutely hexagonal cancellated

Fic. 1.— Arcella vulgaris Ehrenberg. 3100. Showing many air bubbles in the

cancelli and ve structure of the network. Photomicrograph, 4; in. oil-im-

mersion object

structure." Closer study of the test of these two species with high

magnification shows further complication of this structure, not

shown at all in the “honeycomb” figure given by Leidy, Pl. 27,

797

798 THE AMERICAN NATURALIST [Vor. XL

Fig. 35. Moreover, as will be shown later, the arrangement of

the hexagons is on an entirely different plan from that shown in

Leidy’s figure and those of other authors.

Hertwig and Lesser (Arch. f. mikr. Anat., vol. 10, suppl., 1874)

after reviewing and rejecting the conclusions of Dujardin, Ehren-

berg, Claparéde, Carter, and Wallich go rather fully into the more

minute structure of the test and reach a positive conclusion as

follows (p. 96): “Ihrer feineren Structur nach besteht die Schale

aus zwei Platten, einer äusseren und einer inneren, welche einan-

Fic. ies Arcella vulgaris eua maia X3100. Showing the introduction of col-

of plates and resulting change in the number of sides of the plates

a, nn plate; 5, b, pdea with more than one column initiated.

der parallel gelagert sind und durch em bienenwabenartiges,

hexagonale Figuren bildendes Fachwerk vereint werden ”

Hertwig and Lesser, by treatment of the test with sodium

carbonate and acetic acid induced the formation of bubbles of

carbonic-acid gas in the cancelli, which they considered closed

chambers. In our specimens many bubbles of air were introduced

into the cancelli with the greatest ease in the following manner.

From about the entire test, under low power, the water was

No. 479] FINER STRUCTURE OF ARCELLA 799

drawn away until its level was so reduced that air reached the

specimen. Bubbles at once formed in some of the cancelli and

were present after dehydrating, clearing, tearing in pieces, and

mounting in balsam or styrax. Many of these air bubbles are

seen in Fig. 1, and a few are scattered about in Fig. 2. The ready

entrance of air to form bubbles in the cancelli hardly seems to bear

out the view that there are two thin plates, with the cancellated

network lying between, as Hertwig and Lesser thought. If there

were two membranes, it would be impossible, by the simple method

adopted in this work, to cause air bubbles to form in the closed

chambers lying between

them. That there is but

one membrane is very

strongly indicated by the

present study.

The next thing to deter-

mine was the position of the

single membrane, whether

it ison the outer or the inner

side of the network. In the

introduction of air bubbles

the specimens were placed

with the mouth-opening Fic, 3.— Diagrammatic representation of the

š ae of the upper surface of the network.

downward, the shell cavity

being filled with water. At no time was the water allowed to

become low enough to permit air to enter the mouth. In this

manner only the upper surface was exposed, and no air could have

entered the cancelli from the inside. Moreover, had air entered

the shell cavity, it would at once have become evident as a large

air bubble at the upper part of this cavity. The introduction of

air having been thus controled, we conclude that the bubbles

formed on the outside of the membrane, and therefore that the

raised pattern or network projects externally.

The form of this network, as has been said, is radically unlike

the honeycomb structure heretofore assigned to it. It is, to be

sure, hexagonal in its main features, but the arrangement of the

hexagonal areas is not at all what it has been represented. In

the honeycomb arrangement the hexagons have sides in common.

800 THE AMERICAN NATURALIST [Vor. XL

In the Arcella test the hexagons have no sides in common. Instead,

the hexagonal areas are so placed that the three adjacent sides of

three neighboring areas enclose a small triangular space. Just

here we find a further complication of the structure. These

interpolated triangles are not solid portions of the network, but

themselves contain areoles of subtriangular outline. The density

of the medium through which the light is transmitted seemed,

with the best illumination obtainable, the same in the small tri-

angular areoles as in the larger hexagonal areas. From this we

concluded that the areoles are depressed areas in the network

n e d a

? bt te Au

Tm IA,

Fic. 4.— Arcella mitrata Leidy. X1200. Photomicrograph showing structure

of network like that in A. vulgaris.

similar, except in point of size and shape, to the hexagonal areas.

Diagrammatically then, the network may be conceived as formed

of straight lines in three sets of parallels, the lines of each set mak-

ing an angle of sixty degrees with those of the two other sets (see

diagram, Fig. 3)J. A comparison with the actual photographs,

especially Fig. 2, seems to bear out this conclusion. "That no air

bubbles formed in the smaller spaces is natural, since the surround-

ing areas are much larger and of equal depth.

No. 479] FINER STRUCTURE OF ARCELLA 80]

When the test was seen in optical section the reason for the view

that there are two membranes was apparent, for the limiting upper

edges of the raised network give the appearance of a wall covering

in the top. ‘This appearance seems to be merely the effect of re-

fraction of light. ‘The basal membrane may be clearly seen. In

general the height of the raised network above the basal membrane

is about equal to the width of the hexagonal areas.

Besides the further complication of structure in the test, another

Fic. 5.— Arcella mitrata Leidy. X3300. oe of a portion of the

specimen shown in Fig. 4, but much enlarg

series of observations was made on the method of growth of the

shell. As the animal increases in size toward the periphery, this

increase must in some way be provided for. An increase in size of

the hexagons might have been used but this would have been detri-

mental to the plan of structure. Instead of this, new columns of

hexagonal areas are added or interpolated among the previous ones.

By this means the plan of structure is not seriously interfered with.

‘These new columns may be added in any of three directions con-

forming to the directions of the three sets of parallel lines already

referred to.

802 THE AMERICAN NATURALIST [Vor. XL

In typical cases the new column of plates is initiated by an area

having but five instead of six sides. To compensate for this

mechanically, the preceding area has seven sides (Fig. 2, a).

This equating method of heptagons and pentagons is typical

whenever a single column is added in one spot. In certain cases,

however, more than one column may originate, even with the same

area, and then various irregularities are taken on (Fig. 2, b). In

such cases, areas with but four sides are met with occasionally

instead of the normal pentagonal areas. Besides this variation

in the number of sides of the areas in different portions there seems

to be a definite alternation of the columns, to the right and left of

the axis in which they are added. ‘This applies of course only to

those columns added successively in one of the three directions

mentioned above.

Altogether, the test of Arcella is far from the simple hexagonal

structure figured by Leidy and other authors. Its complexities

are worthy of further study and comparison with the tests of other

rhizopods.

NOTES AND LITERATURE

ASTRONOMY AND PHYSICS

A Laboratory Astronomy.' — This book is the outcome of the

author’s experience in handling with his large elementary classes in

Harvard College, “those difficult and discouraging” parts of astron-

omy which deal with “the diurnal motion of the heavens and the

apparent motions of the sun, moon, and planets among the stars.”

It is suggested that each student ought to make for himself, and dis-

cuss carefully, a great number of simple observations, so that the

facts to be brought out may become a part of his own experience.

The apparatus required, most of which has been especially designed

for this work, is so inexpensive that each student can be supplied

with a complete outfit. This makes it possible for all the members

of a class to do similar work at a given time — “a principle of cardi-

nal importance in elementary laboratory work with large classes."

The book is intended primarily for teachers and should be used in

connection with a descriptive text-book.

No one who knows Professor Willson personally, will need the re-

viewer's assurance of the remarkable ingenuity of his methods, or of

the admirable qualities of his style. ‘This book is a fine example of a.

modern tendency, new in astronomy, but fortunately well established

in physics and chemistry, of carrying interesting laboratory work into

the very beginning of a student's acquaintance with natural science.

A feature of interest to the general reader is a well written chapter

on the contents and use of a nautical almanac, with a full set of speci--

men pages.

H. N. D.

A Laboratory Physics.? — This book, like the one just reviewed,

is intended as a laboratory manual for a large elementary course in

Harvard College, and presents such material as might form a set of

1 Willson, Robert W. A Laboratory Astronomy. Boston, Ginn and Co.,

1906. 8vo, ix + 189 pp.

? Sabine, Wallace C. A Student's Manual of a Laboratory Course in.

Physical Measurements. Rev. ed., Boston, Ginn and Co., 1906. 8vo, vi +

97 pp.

803

804 THE AMERICAN NATURALIST [Vor. XL

“daily lectures preceding the laboratory work and describing the

experiments to be performed.” It is, nevertheless, remarkable for

its freedom from the pedantic, cut-and-dried, schedule method of

presentation which so frequently characterizes elementary laboratory

manuals, for many of Professor Sabine’s pages are Inteleshing reading

as such, and throughout, “too specific instruction” has been avoided

as tending “not only to deprive the student x —— M but also to

make any departure in the apparatus confusing.

As a matter of fact the spirit of the book would have been better

expressed by reversing the order of these two clauses, for “in the

majority of cases the description is purposely not such as will admit

of a mechanical and unintelligent interpretation." In particular,

the three-page introduction is an unusually fine presentation of the

point of view from which a student should attack the work which is

‘to follow.

The experiments described are representative of nearly the whole

range of elementary physics. They should properly be preceded

by the still more elementary work of a modern high-school course,

as much of the apparatus requires comparatively skilful and appre-

-ciative handling. Two short appendices on “significant figures”

* graphical representation" are especially worthy of mention.

H. N. D

BIOLOGY

Clements's Research Methods in Ecology ' is the outcome of some

-eight years of practical work by the author in the experimental study

of the factors that determine the distribution and adaptive modifi-

cations of plants. Students of this comparatively new branch of

.science are to be congratulated on the possession in this volume, of a

concise statement of the aims, methods, and problems of ecology.

"The author points out that the greater part of so called ecological

.study has hitherto been very superficial and of comparatively little

value, largely because of a failure to recognize and measure accu-

rately the several factors that determine for each species its particular

-environment.

‘Clements, F. E. Research Methods in Ecology. Lincoln, Neb., Uni-

-versity Publishing Co., 1905. 8vo, xvii + 334 pp., gs.

No. 479] NOTES AND LITERATURE 805

The subject matter is considered under four main heads. Chapter

Iis devoted to a general statement of the scope of ecology. Chapter II

deals with habitat, and contains a description of the instruments

and methods used in recording water-content, light-intensity, tem-

perature, soil, and other factors upon which the organism is dependent.

Many of the methods described, have been elaborated by the author

in his own extensive work in the West. Chapter III, the Plant,

considers the general relations, adaptations, and reactions of the

separate organism, while Chapter IV deals with the Formation in

its various aspects, and the methods of studying the relations that

groups of plants bear to one another and to their environment.

This work should do much towards establishing ecology and experi-

mental plant evolution upon a firmer basis by pointing out the need

and the method of making absolute determinations of factors, instead

of the inaccurate generalizations so often recorded. The time is

also not far distant when it will be a simple matter to determine, by

an examination of a given soil in a given situation, what plants are

. best adapted to any portion of a single farm, so that agriculture may

be carried on under much more precise regulations.

Although plants alone are dealt with in the present volume, many

of the methods described will have to be used in a more exact study

of animal habitats, and here lies a large field as yet hardly more than

touched upon. The author recognizes the zonal distribution of

continental forms, and proposes a new nomenclature for these as

occurring in North America. Apparently, however, the areas already

recognized and named by American zoólogists are ignored, and the

new classification given, does not seem as adequate as that now in

use by the latter.

A glossary, including numerous terms proposed by the author,

and a bibliography of plant ecology complete the book. Notwith-

standing the very detailed statement of contents, the lack of an index

is a disadvantage.

G. M. A.

Moore's Universal Kinship ' is intended as a protest against that

attitude of the human mind that would conceive all animals other

than man as man's just and legitimate prey. The author appears

to have become greatly impressed by Darwin's conception of the

1 Moore, J. H. The Universal Kinship. Chicago, Chas. H. Kerr and

Co., 1906. 12mo, x 4- 330 pp. $1.00.

806 THE AMERICAN NATURALIST [Vor. XL

ultimate consanguinity of all sentient beings, and addresses himself

to the task of arousing in man a greater feeling of sympathy for his

fellow creatures. The argument falls under three heads: man’s

physical relation to other animals, his psychical similarity to them

in certain fundamental ways, and hence his ethical kinship. The

author concludes that the fact “that vertebrate animals, differing in

externals as widely as herring and Englishmen, are all built according

to the same fundamental plan, with marrow-filled backbones and

exactly two pairs of limbs branching in the same way, is an astonishing

coincidence”; hence the fancied superiority of the human race is but

a figment of man’s mind for ‘‘man is not a god, nor in any imminent

danger of becoming one.”

While agreeing with the author that “the art of being kind” is in

sore need of cultivation among us, one cannot but be amused at the

mixture of fact and error, observation and travelers’ tales, seriousness

of statement and straining after absurd expressions, that characterizes

this not unreadable book.

G. M. A.

ZOOLOGY

Pratt’s Vertebrate Zoology.'— In continuation of the plan of

his Invertebrate Zoölogy, published some three or four years ago, Dr.

Pratt now offers a similar guide to the dissection of vertebrates, which

would appear to merit the same favorable reception accorded to the

earlier volume. As a guide to vertebrate dissection its chief claim

to usefulness over the already existing laboratory manuals on the

subject lies perhaps in the fact that it includes under one cover those

forms most frequently employed in American laboratories, for descrip-

tions of which the teacher or student has formerly found it necessary

to refer to two or three separate works. Outlines are furnished for

the dissection of seven types, viz.: dogfish, perch, mud-puppy (Nec-

turus), frog, turtle, pigeon, and cat. Of these, that of Necturus

will probably be especially acceptable, since it is a form epus ee

! Pratt, Henry Sherring. A Course in Vertebrate Zoölogy. A Guide to

the Dissection and Comparative Study of Vertebrate Animals. Boston, Ginn

and Co., 1905. 8vo, x + 299 pp.

No. 479] NOTES AND LITERATURE 807

employed for laboratory work in connection with courses on com-

parative vertebrate anatomy, and heretofore no published outline

for its dissection has been generally accessible.

The question as to the practical and pedagogical value of snitch

of this nature remains, as before, an individual one with different

teachers. In respect to method of treatment the present outlines

offer few innovations; but apparently the attempt has been made to

have them as practical as possible, so that they may, if it is desired,

be placed in the student’s hand with little or no modification. To

this end the descriptions are made rather fuller than some instructors

might consider desirable, especially those who believe that laboratory

outlines should consist merely of a framework of directions as to the

method of proceeding to work, together with suggestive questions,

rather than a description of what the student is expected to see. Dr.

Pratt has largely overcome this objection by the relatively great num-

ber of original drawings called for. Satisfactory drawings insure

that the student has seen what is described, and the omission of all

illustrations from the book will make him dependent upon his own

observations in supplying these.

Loc

Stephens's California Mammals' is a handbook written to

popularize the study of the rich mammalian fauna of that State.

In addition to a brief description of each species with a statement of

its distribution, the author has given a number of field notes on the

forms that have come under his personal observation. ‘The accounts

of the Cetacea are taken from Scammon as the author has had no

experience with them. The nomenclature used for these animals

is in some cases not that now in vogue. The scientific names of the

species considered, are followed by the name of the authority as usual,

but the author tells us that he has omitted the parentheses in all cases

where they are usually employed. This seems a mistake in a work

of this sort. The chapter on life zones is accompanied by a chart

showing the location of these areas. A check-list and glossary are fol-

lowed by a very complete index. Several rather characterless wash

drawings serve as full page illustrations.

The work can be but preliminary, the author states, but undoubtedly

it will be of value as a basis for a more thorough investigation.

!Stephens, F. California Mammals. San Diego, Cal., West Coast Pub-

lishing Co., 1906. 8vo, 351 pp., illus. $3.50.

808 THE AMERICAN NATURALIST [Vor. XL

Ichthyological Notes.—In the Bulletin of the Bureau of Fisheries

(vol. 25, 1905), Dr. Barton W. Evermann has a beautifully illustrated

memoir on the “‘ Golden Trout of the High Sierras." In small streams

tributary to Kern River, along the flanks of Mount Whitney are found

small trout, very gorgeously colored, with brilliant golden and orange

shades on the bodies and fins. These colors harmonize with the

orange colors of the underlying rocks. Recently Dr. Evermann, at

the request of President Roosevelt, conducted an investigation of

these trout. He finds them probably descended from the Kern River

Trout (Salmo gilberti Jordan), but modified in size, in coloration,

and in the reduction of the scales. From the Kern River Trout, the

Golden Trout are separated by impassable waterfalls. But still more

remarkable is the fact that in each of the three different streams thus

isolated, there is a different type or species of Golden ‘Trout.

Besides the original species, Salmo aguabonita Jordan, from South

Fork of Kern River, Evermann describes two new species, closely

allied to this, but each sprung independently from the same parent

stock. These species are: Salmo roosevelti Evermann, from Volcano

Creek, and Salmo whitei from Soda Creek.

It is not certain whether the vivid colors of each of these three

species are protective, due simply to natural selection, or whether

to some more obscure influence acting on all individuals in these

mountain brooks. The paper is illustrated by paintings by Charles B.

Hudson and by maps and photographs of the waterfalls and streams

within the habitat of the Golden Trout.

In the same Bulletin for 1904, Dr. Charles Wilson Greene of the

University of Missouri has published his studies of the physiology

of the Chinook Salmon, a species of especial interest from the fact

that every individual dies after reproduction.

In the Smithsonian Miscellaneous Collections, 1905, vol. 48, Mr.

Barton A. Bean gives an account of the Whale Shark (Rhinodon

typicus), the largest of the sharks, a specimen of which has been

lately taken on the coast of Florida. The same shark has been de-

scribed from the Gulf of California as Micristodus punctatus, and

lately from Japan as Rhinodon pentalineatus.

In the same number, Dr. Theodore Gill gives an essay on the

Cyprinoid fishes, with figures of numerous species and a discussion

of the vernacular names current in England and America.

In the Proceedings of the Washington Academy of Science, Robert

E. Snodgrass and Edmund Heller record the fishes taken about the

No. 479] NOTES AND LITERATURE 809

Galapagos Islands by the Hopkins-Stanford Expedition of 1898;

184 species are recorded, with synonymy and valuable notes on their

characters and geographical distribution. The new species has been

described in a previous paper.

In the same Proceedings, Mr. William F. Allen, also of Stanford

University, describes in great detail the lymphatic system in the

large Californian Sculpin or Cabezon, Scorpenichthys marmoratus.

In the Proceedings of the Royal Society of Edinburgh, Dr. Louis

Dollo describes the abyssal fish, Bathydraco scotie. `

In the Proceedings of the Biological Society of Washington (1905)

Dr. Seth E. Meek, records a collection of fishes from the Isthmus of

Tehuantepec. Cichlasoma zonatum, from Oaxaca, is described as

new. Dr. Meek also describes two new species, Pimelodella eigen-

manni from Sao Paulo, Brazil, and Anisotremus williamsi from

Santos.

In the Proceedings of the Philadelphia Academy for 1905, Mr.

Henry W. Fowler discusses a collection of ninety species of fishes

from the Baram Basin in Borneo. Most of these are fresh-water

species, several new genera and species being described. One goby,

Gigantogobius jordani, allied to Eleotris, reaches a length of 26 inches.

Numerous papers in the Annals and Magazine of Natural History

by C. Tate Regan, treat of fishes. The following matters may be

noted: Regan records the European shark, Hexanchus griseus, from

Japan and concludes that the Californian species, Hexanchus cori-

nus is not distinct from it. He gives reviews of various groups of

South American fishes, especially Cichlidze and Loricariide. A new

white-fish, Coregonus gracilior, is described from the Lakes of Cumber-

land. A monographie review of the family Galaxiide is given by

Mr. Regan in the Proceedings of the Zoölogical Society of London.

Dr. George A. Boulenger, as President of the Zoólogical Section of

the British Association for the Advancement of Science (1905), dis-

cusses in illuminating fashion the distribution of African fresh-water

fishes. In the Annals and Magazine of Natural History, July, 1905,

Dr. Boulenger gives a list of the fresh-water fishes of Africa with the

distribution of each species. In the Proceedings of the Zoölogical

Society, he records the fishes of Lake Chad. All the species are

common both to the Nile and the Niger, a fact which indicates that a

connection between these rivers formerly existed through Lake Chad.

810 THE AMERICAN NATURALIST [Vor. XL

In the Scientific Investigations of the Fisheries of Ireland, for 1905,

Messrs. E. W. L. Holt and L. W. Byrne, give a “First Report on the

Fishes of the Irish Atlantic Slope.” A new species is Melamphaés

eurylepis. Nettophichthys retropinnatus of Holt is shown to be the

young of the eel, Synophobranchus pinnatus. The genus Myctophum

in this paper is called by the much later name of Scopelus.

Professor Keinosuke Otaki, and his associates, Fujita and Hig-

urashi, continue their beautifully illustrated work on the fishes of

Japan. In the third issue are included the Kurodai (Sparus schlegeli),

the Maguro, or Tunny (Thunnus schlegeli = ? Thunnus thynnus),

the Maiwashi or Japanese Sardine (Sardinella melanosticta), the Kon-

oshiro (Konosirus punctatus), and the Common Goldfish or Funa.

The press work in this series is beautifully done, and the text is accu-

rate and helpful.

In the Journal of the College of Science (vol. 20, 1905) of the Impe-

rial University of Tokyo, Shigeho Tanaka has an account of two new

species of Japanese Chimeras. It is a remarkable fact that of the

ten known living species of this ancient and extraordinary genus,

five are known from Japan only, and the center of distribution of

each of these is Sagami Bay, which is the first indentation south of

the Bay of Tokyo. Mr. Tanaka describes Chimera jordani and

Chimera owstoni as new species, in addition to the three, Chimera

phantasma, Chimera mitsukurii, and Chimera purpurascens already

described from the waters about Misaki. When we consider the num-

ber of rare or ancient sharks recorded from this region, the extraordi-

nary richness of the Bay of Sagami in shark-like types becomes

very apparent. It was from Sagami Bay that Garman obtained

Chlamydoselachus and Mitsukuri the “Goblin Shark," called Mitsu-

kurina. In the same bay is a Rhinachimera, a Heterodontus, and

many species of Squaloid sharks, one of them with luminous areas

on the body.

Other Japanese sharks are described by Garman in the Bulletin of

the Museum of Comparative Zoölogy (vol. 46, 1906). These are:

Parmaturus | pilosus, Centrophorus acus, Centrophorus tessellatus,

, Acanthidium rostratum; Acanthidium aciculatum, and Centroscymnus

owstoni. To Parmaturus, the Japanese species, Pristiurus eastmani,

is also referred, as also Catulus xaniurus from California. Garman

refers the genus Deania to the synonymy of Acanthidium and Zameus

to that of Centroscymnus. Squalus uyatus of Italy is referred to

Centrophorus. Garman describes Hemigaleus pectoralis, as a new

species from the New England Coast.

No. 479] NOTES AND LITERATURE 811

Japanese fishes are also discussed in several papers in the Pro-

ceedings oj the United States National Museum for 1905. Jordan

and Seale describe six new species from different parts of Japan,

the most notable being a new genus, Sayonara, near Anthias. The

fishes of the islands of Yaku and Tanega, as collected by Robert

V. Anderson, are recorded by Jordan and Starks. Seven of these,

mostly blennies, are figured as new. Jordan and McGregor describe

as new, the Japanese Threadfin or Agonashi, Polydactylus agonasi.

Jordan reviews the sand-lances of Japan, and Jordan and Snyder

review the sturgeons. An elaborate paper on the many species of

flounders and soles of Japan is by Jordan and Starks. Jordan and

Herre review the Japanese herrings, and Snyder the Japanese sur-

mullets. Jordan and Snyder discuss the Giant Bass of Japan, Ste-

reolepis ischinagi, a species closely related to the California Jew-

fish, and Erilepis zonifer, the huge Aburabodzu or Fat-priest of Japan.

This species was first known from a single specimen taken by Locking-

ton in the Bay of Monterey.

Jordan and Snyder discuss the killifishes of Japan, and also the

Chinese loaches of the genus Misgurnus. The fishes of Shanghai

are discussed by Jordan and Seale, and those of Port Arthur by

Jordan and Starks. Among the latter is a remarkable new genus

of gobies, Ranulina, with the teeth fringe-like about the rim of the

mouth.

Mr. Edwin C. Starks reports on the collection of fishes made in

Ecuador and Peru, by the late Mr. Perry O. Simons, a most promising

Stanford student, conducting explorations for the British Museum,

who was murdered by highwaymen in Bolivia in 1899. In the same

Proceedings, Dr. Evermann and H. W. Clark describe three new

species from Santo Domingo, Platypecilus perugie, Platypeeilus

dominicensis, and Sicydium buscki. Eugene W. Gudger discusses

the breeding habits and embryology of a species of pipe-fish, Syngna-

thus floride.

In the Proceedings of the Davenport Academy of Sciences (vol. 10,

1905), the memorial volume dedicated to Mrs. Putman, the honored

patron of the Academy, Jordan and Seale discuss the fishes of Hong

Kong. This paper is beautifully illustrated, two of the plates being

colored.

In the National Geographic Magazine, 1905, Dr. Hugh H. Smith

treats in detail of the Japanese fisheries.

812 THE AMERICAN NATURALIST [Vor. XL

In the Zoölogisches Jahrbuch for 1905, is a paper by the late Pro-

fessor Franz Hilgendorf of Berlin on fishes from East Africa.

Dr. Robert Collett, in the Forhandlinger Videnskabs Selskab of

Christiania for 1905, continues his monographic reviews of the fishes

of Norway.

In the Paeifie Monthly, Portland, April, 1906, Jordan describes in

popular fashion the trout and salmon of the Pacific, with drawings.

by Sekko Shimada.

In the Popular Seience Monthly for April, 1906, Jordan records.

the occurrence in considerable numbers at Avalon in Southern Cali-

fornia, of the Japanese Hirenaga or Yellow-fin Albacore, Germo

macropterus. This large game fish, known by its citron yellow fin-

lets occurs also in Hawaii.

In the Paris Bulletin d'Histoire Naturalle, Dr. Jacques Pellegrin

discusses the fishes of Lake Baikal, known as Cottocomephorus.

In the Journal of Sciences of Lisbon, 1904, Dr. Balthazer Osorio

has a catalogue of the fishes of Cape Verde, and in the same journal

are various notes on other fishes.

In the American Naturalist (vol. 39, 1905), Miss Julia Worth-

ington discusses the Myxinoids or hag-fishes, as studied by her at the

“Stanford Seaside Laboratory at Pacific Grove. Miss Worthington

rejects the genus Polistotrema, detached from Eptatretus (which she

calls by the much later though more familiar name of Bdellostoma),

regarding the number of gills as having barely specific importance.

The separation into genera may be questionable, but there is as yet

no adequate reason for placing all these variant forms in a single

species, an arrangement first suggested by Dr. Howard Ayers.

In the Bulletin of the American Museum of Natural History, Mr.

L. Hussakof gives a valuable account of the structure of two species

of Dinichthys. In the American Journal of Science, Dr. C. R. Eastman

makes a strong argument in favor of the dipnoan affinities of the

Arthrodires. He goes far towards placing Woodward’s view of the

case on a sound foundation. The contention of Eastman rests

largely on the intimate relationship of the dipnoan Neoceratodus

to the Arthrodires on the one hand and to characteristic dipnoans

on the other, the living genus Neoceratodus being more primitive

than either of the extinct types with which it is compared. Dr.

No. 479] NOTES AND LITERATURE 813.

Eastman does not believe that dipnoans are descended from Crossop-

terygians, but rather that they may have come from the Pleuracanthus-

like sharks. The association of the Arthrodires with the Dipneusti,

finally disposes of the group of Placodermata, in which the Arthro-

dires were associated with the Ostracophores.

In the Bulletin of the University of Montana, Dr. James A. Hen-

shall gives a list of the scant fish fauna of Montana, 36 species being

represented, with notes on the game fishes represented or introduced

into the State.

In the Hawaiian Forester (vol. 2, 1905), Mr. Alvin Seale gives an

account of the successful introduction from Galveston to Honolulu

of three species of mosquito-eating killifishes. These are Molli-

nesia latipinna, Fundulus grandis, and Gambusia affinis. These

fishes were received in fine condition, and they have shown great.

avidity in freeing Hawaii of her worst insect pest.

In the American Journal of Physiology, 1905, Professor G. H.

Parker discusses the stimulation of the integumentary nerves of

fishes by light. The sensitiveness to light of the vertebrate skin is

established. This trait may have served as a basis from which the

retinal structures and the temperature sense were derived.

In the Marine Biological Association Report (vol. 1, 1903), are

. elaborate studies of the Plaice, Pleuronectes platessa. Dr. William

Wallace has investigated the growth rate of the species. Walter

Garstang reports on the topographical distribution of the species.

A number of studies on the natural history of the Plaice are recorded

in German by Mr. Garstang in Rapports du Conseil International

pour l'Exploration de la Mer, 1905.

In Ergebnisse der Schwedischen Südpolar Expedition (vol. 5, 1905)

Dr. Einar Lönnberg describes and figures numerous new Antarctic

fishes. Lönnberg also furnishes (Kong. Vet. Aarsbog, 1906) bio-

graphical sketches of the Swedish ichthyologists, Petrus Artedi and

the late Fredrik Adam Smith (1839-1904).

In the Archivos do Museo Nacional do Rio de Janeiro (vol. 13, 1906),

Alipio de Miranda Ribeiro records the vertebrates of Itatiaya, Brazil,

and gives a review of the species of the Characin genus Megalabrycon.

In the Journal of Anatomy and Physiology, Mrs. Onera A. M.

Hawkes of the University of Birmingham describes the important

814 THE AMERICAN NATURALIST [Vor. XL

discovery of a vestigial sixth branchial arch in the shark, Heterodontus.

As in the more primitive groups of Hexanchid:z and Chlamydosela-

chide, there are six or seven gill arches, this discovery of six arches in

the still more ancient group of Heterodontide, the oldest of existing

sharks, is a matter of much interest and importance. The number

five found in all other recent sharks is apparently a matter of special-

ized reduction.

In the Annals of the New York Academy of Sciences, 1906, Dr.

Raymond C. Osburn makes a strong and convincing argument for

the theory of the origin of the vertebrate limbs from fin folds. Dr.

Osburn contends that paired and unpaired fins in fishes are similar

structures and that the evidence is overwhelmingly in favor of the

origin of all fins as local outgrowths from the body wall.

Davip STARR JORDAN

BOTANY

Leaf Structure—A paper by Mrs. Clements, which contains a

historical review of the work previously done along similar lines, is

upon observations made on some 300 species growing under

the varied conditions presented by the Colorado foothills and the

mountains of the Pike’s Peak region of the Rocky Mountains. The

conclusions arrived at support the views now generally held as to the

influence of local conditions upon the histological structure of leaves,

and are based upon exceedingly extensive and precise measurements

relating to water-content of soil, humidity, light, and temperature,

all of which factors are brought into relation with the histological

structure of stem leaves. Thanks to the system of classification

adopted as well as to the numerous comparative tables, the reader

at a glance, is able to note with exactitude the influence of each of

the factors upon leaf structure, in which he is aided by a large number

of excellent illustrations.

The statement: “Full sunlight is equally strong throughout the

regions, and not more intense for high altitudes, as is generally sup-

" [p. 25] is to be noted, in view of Professor Wiesner's recent

conclusions to the contrary.

H. Hus

1 Clements, E. S. “The Relation of Leaf Structure to Physical Factors."

Trans. Amer. Micr. Soc., 1905, pp. 19-102, 9 pls.

No. 479] NOTES AND LITERATURE 815

Light Intensity — Professor Wiesner ! now gives a detailed account

of his measurements of light intensities, made chiefly in the Yellow-

stone Park, and reaches the conclusion that, with a clear sky, the

intensity of the total daylight as well as that of the direct sunlight

increases with the elevation above sea level, while the intensity of

the diffused light decreases with increasing elevation but constant

altitude of the sun. He further finds that the diffused light, in the

course of the day, does not increase correspondingly to the increase

of direct sunlight.

The greater intensity of the total daylight on the surface of the sea

as compared to that on the main land, Professor Wiesner ascribes to

the greater amount of light reflected by water surfaces.

H. Hus

Bilancioni’s Dictionary.— A capital model of a modern botanical

dictionary is afforded by a little book recently published in the Italian

language. Histology, anatomy, morphology, physiology, and the

biology of plants are indicated among the topics treated, and 111

pages are given to a biographic account of distinguished botanists.

The treatment of the several entries ranges from a mere indication

of equivalence in the case of synonymous words to four pages (in-

cluding a classification) for fruit, two and a half for germ-plasma,

three and a half for protoplasm, eleven for tissues, etc. Plant names

do not appear; but common Latin adjectival forms on which specific

names have frequently been framed, are defined, and throughout the

derivation of terms is given.

Ww 5

Notes.— A little pamphlet of 109 pages, by Professor Bessey, has

been issued by the University Publishing Company, of Lincoln,

Nebraska, under the title Elementary Botany. Laboratory and field

instructions are followed by a terse manual of the common genera of

Nebraska plants.

One of the most attractive of recent elementary text-books is Miss

1 Wiesner, J. ‘‘ Beiträge zur Kenntnis des photochemischen Klimas des

Yellowstone-Gebietes und einiger anderer Gegenden Nord Amerikas.”

Denkschr. d. math. naturw. Kl., kaiserl. Akad. d. Wissensch., Wien, vol. 80,

1906.

? Bilaneioni, G. Dizionario di botanica generale. Milano, Hoepli, 1906.

'16mo, xxi + 926 pp. 10 lire.

816 THE AMERICAN NATURALIST [Vor. XL

Stoneman’s Plants and their W ays in South Africa. Familiar facts

are supplemented by (to us) unfamiliar illustrations.

Some new plants from the Canadian Rockies and Selkirks are

described by Miss Farr in The Ottawa Naturalist for August.

Vol. 7 of Engler and Drude’s Vegetation der Erde is devoted to a

part of West Australia, treated by Diels.

Chevalier gives an illustrated account of Adansonia in no. 6 of the

current volume of the Bulletin de la Société Botanique de France.

Mr. A. D. E. Elmer has begun the publication, at Manila, of a

new serial under the title Leaflets on Philippine Botany. The first

number, dated April 8, is devoted to a paper on Philippine Rubiacez,

by the editor.

Goodale has a note on the persistence of Calluna in Massachusetts.

in The American Journal of Science for August.

Viguier publishes: the results of an anatomico-systematic study of

Araliacee in ser. 9, vol. 4, nos. 1-3, of the Annales des Sciences Natur-

elles, Botanique, issued in July.

The flowering of Agave palmeri and A. lecheguilla is reported in

the Journal of the New York Botanical Garden for August.

Aloe campylosiphon is figured by Berger in Die Gartenwelt of August:

Lon

Showers of conifer pollen in Mexico, and its accumulation on the

water in the crater of Toluca, are recorded by Urbina in vol. 3, no.

7, of the Anales del Museo Nacional de Mexico.

An account of the poisoning of horses by Equisetum arvense is given

by Peters and Sturdevant in the 19th Annual Report of the Agricul-

tural Experiment Station of Nebraska, which also contains a paper

on a disease of the Cottonwood due to Elfvingia megaloma, by Heald,

and a study of the relation of early maturity to hardiness in trees, by

Emerson.

The second supplement to vol. 1 of The Philippine Journal of

Science, issued on June 15, is devoted to descriptions and figures of

new Philippine ferns, by Copeland.

A fully illustrated article on fern buds is published by Kupper in.

Flora of July 25.

No. 479] NOTES AND LITERATURE 817

Evans contributes some notes on Japanese Hepatic® to the Pro-

ceedings of the Washington Academy of Sciences for August.

A monograph of Swiss Myxomycetes, by Schinz, has been separately

issued from Heft 6 of the Mitteilungen der naturwissenschaftlichen

Gesellschaft in Winterthur, for 1906.

. Portraits of Bateson and several other well known plant breeders

or botanists are published in The Gardeners’ Chronicle of August 4.

MacDougal discusses discontinuous variation in pedigree culture

in The Popular Science Monthly for September.

Earle publishes a considerable paper on Cuban fungi, with numer-

ous half-tone illustrations, in the Primer Informe Anual de la Estaciön

Central Agronómica de Cuba, bearing date of June 1.

A scholarly study of Jugendjormen und Bliitenreife im Pflanzen-

reich, by Diels, has been issued from the Borntr&ger press of Berlin,

as an attractively printed, well illustrated pamphlet of 130 pages.

The double number of the Botanische Zeitung issued on July 15 is

devoted to a paper by Vöchting on regeneration and polarity in the

higher plants.

A study of the fall of the terminal buds, characteristic of certain

trees, is separately issued by Tison from the Bulletin de la Société

Linnéenne de Normandie for this year.

Details of experimental studies of the effect of frost on trees are

given by Soranes in vol. 35, no. 4, of the Landwirtschajtliche Jahr-

bücher, issued in July.

A series of six well illustrated articles on the differentials of trees

in winter was published by Professor Weed in the issues of Forest

and Stream between January 6 and March 31, of this year.

A short appreciative note on Burbank is printed by de Vries in

The Independent of May 17.

An illustrated account of the botanical garden of Cambridge,

England, is given by Zahu in Die Gartenwelt for August 18.

An instructive discussion of variations in animals and plants is

contributed by Jordan to The Popular Science Monthly for June.

An account of de Vries and his critics is given by Gager in Science

of July 20.

818 THE AMERICAN NATURALIST [Vor. XL

A somewhat radical analysis of plant study and nomenclature is

published by C. F. Baker in Science of May 25.

A plea for the proper use of “mega” and “macro” in terminology

and nomenclature is published by Chamberlain in Science of May 25.

Papers on the flora of the Amazon region are being published by

Huber in current issues of the Boletim do Museu Goeldi of Pará.

A list of the Bryophytes and higher plants — so far as determined

— of the Lamao Forest Reserve is published by Merrill as vol. 1, sup-

plement 1, of The Philippine Journal of Science; and a discussion of

the vegetation of the Reserve, by Whitford, is contained in nos. 4 and

6 of the same volume.

A third part of de Wildeman's * Enumeration des plantes récoltées

par Emile Laurent:...pendant sa dernière mission au Congo,"

issued in June from the Vanbuggenboudt press of Brussels, reaches

p. 354 and pl. 106.

Vol. 4, part 4, and vol. 5, part 3, of Wood's Natal Plants have

recently been issued, bringing the former volume to completion.

Further studies of the botany of Kerguelen, St. Paul, and New

Amsterdam are being published by Schenck in the Wissenschaftliche

Ergebnisse der deutschen Tiefsee Expedition of the Valdivia.

The seed and seedling of Trollius albiflora are described by Ramaley.

in University of Colorado Studies for March.

Further additions and changes are made in Eschscholtzia by Fedde

in late numbers of Repertorium Novarum Specierum.

Professor Greene, in his Leaflets of June 5, expresses a belief in

the existence of some hundreds of species of acaulescent violets in the

United Stätes, and a disbelief in the existence of any hybrids in the

group.

An economic account of Erodium cicutarium in Arizona, by Thorn-

ber, forms Bulletin no. 52 of the Agricultural Experiment Station of

that Territory.

The genus Neobrittonia is proposed by Hochreutiner, in vol. 9

of the Annuaire du Conservatoire et du Jardin Botaniques de Genéve,

for the reception of Sida acerifolia Lag.

A large increase in the species of Ptelea is noted by Greene in vol.

No. 479] NOTES AND LITERATURE 819

10, part 2, of Contributions from the U. S. National Herbarium,

issued in July.

Hybridization in Eucalyptus is analyzed by Maiden in vol. 10 of

the Report of the Australasian Association jor the Advancement of

Science, recently distributed.

Piqueria, Ophryosporus, Helogyne, and other Eupatoriaceous.

Compositze are the subject of new series 32 of “Contributions from

the Gray Herbarium of Harvard University," by Robinson, which

appears as vol. 42, no. 1, of Proceedings oj the American Academy

of Arts and. Sciences.

An illustrated monograph of Epilobium, by Léveillé, is being pub-

lished in the Bulletin de l'Académie Internationale de Géographie

Botanique.

A revision of 17 genera of North American Vernonioid Composite,

by Gleason, has been separately issued from vol. 4, no. 13, of the

Bulletin of the New York Botanical Garden.

A third paper on Canadian Antennarias is published by Greene in

The Ottawa Naturalist for July.

Rhododendron vaseyi is figured in Curtis’s Botanical Magazine for

June. i

An economic account of the mango and its diseases in Hawaii, by

Higgins, forms Bulletin no. 12 of the Hawaiian Agricultural Experi-

ment Station.

A good account of the pecan and its varieties is given by Hume in

Bulletin no. 85 of the Florida Agricultural Experiment Station.

A mammoth plant of Anthurium veitchi is figured in Möllers

Deutsche Gärtner-Zeitung of June 2.

A comprehensive thesis on the “Scobiform” seeds of orchids and

other plants, by Hirt, forms no. 30 of the Mitteilungen aus dem botan-

ischen Museum der Universität, Zürich.

An illustrated account of the cultivation and preparation of fiber

from Phormium is given by Fulton in the Annual Report for 1905

of the New Zealand Department of Agriculture.

An important account of certain Indian bamboos is being published

by Brandis in current issues of The Indian Forester.

820 THE AMERICAN NATURALIST [Vor. XL

Endlich gives an economic account of “Zacaton,” — species of

Epicampes, — in Der Tropenpflanzer for June.

The synonymy of Eriophorum chamissonis is discussed by Holm

and Fernald in The Ottawa Naturalist for June.

Illustrations of the curious Karasaki specimen of Pinus thunbergii

are given by Miyoshi on plates 29 and 30 of his Atlas of Japanese

Vegetation.

A short illustrated account of Sequoia sempervirens is given by

Elliott in Forest Leaves for June.

Morphological notes on Cycads are published by Seward in vol.

13, part 5, of the Proceedings of the Cambridge Philosophical Society.

Part 3 of Grout's Mosses with Hand-Lens and Microscope bears

date June, 1906.

An account of the morphology of the fern stem, illustrated by

Dennstedtia punctilobula, is published by Conard in no. 187 of the

Johns Hopkins University Circular.

A monograph of Scapania, forming a quarto volume of 312 pages,

with 52 plates, has been published by Müller as vol. 83 of the Nova

Acta der k. Leop.-Carol. deutschen Akademie der Naturforscher.

A revision of the Charex of North America, by C. B. Robinson, is

separately printed from vol. 4, no. 13, of the Bulletin of the New York

Botanical Garden.

Part 2 of Holway's North American Uredine® deals with species

of Puccinia found on Moracez, Santalacex, Aristolochiaces, Poly-

gonaces, Amarantacez, Portulacacex, Caryophyllaces, Crucifere,

Saxifragacez, Crassulacex, and Rosacee. A notable feature of the

work is the frequent illustration, by photo-mierographs from type

material, of species reduced to the status of synonyms.

The effect of symbiotie fungi in the germination of Odontoglossum

is illustrated by Bernard in The Orchid Review of July.

A contribution to a revision of the North American Hydnaceæ, by

Banker, forms vol. 12, no. 2, of the Memoirs of the Torrey Botanical

Club. :

A preliminary list of some 500 higher fungi collected about St.

Louis has been published by Glatfelter in vol. 16, no. 4, of the Trans-

actions of the Academy of Science of St. Louis.

No. 479] NOTES AND LITERATURE 821

Further infection experiments with Erysiphe graminis, confirming

the current conclusions as to its physiological differentiation on differ-

ent hosts, are recorded by Reed in a paper separately printed from

vol. 15, part 1, of the Transactions of the Wisconsin Academy of

Sciences, Arts, and Letters.

*, Salmon figures the Venturias and associated Fusicladiums of apple

and pear in The Gardeners’ Chronicle of July 14.

Gleosporium psidü is shown by Sheldon, in Bulletin 104 of the West

Virginia University Agricultural Experiment Station, to develop an

ascigerous stage pertaining to the genus Glomerella,— on the para-

physes of which he has a note in Science of June 1.

An illustrated paper on the fungi of scale insects is published by

Parkin in vol. 3, part 1, of the Annals of the Royal Botanic Gardens,

Peradeniya.

An account of fungi and plant diseases, by Clinton, forms part 5

of the Report of the Connecticut Agricultural Experiment Station for

1906.

A large number of foliar acarodomatia are described by de Wilde-

man in vol. 30, no. 2, of the Annales de la Société Scientifique de Brux-

elles.

An extensive study of palm germination is published by Gatin in

the Annales des Sciences Naturelles, Botanique of June.

A further account of acarodomatia is given by Borzi in vol. 4, no. 1, ,

of Contribuzioni alle Biologia Vegetale, published from the Botanical

Institute of Palermo.

Three ferns and 199 flowering plants which grow on trees (without

being epiphytes) in parts of Italy are enumerated by Ugolini in the

Commentari dell’ Ateneo di Brescia for 1905.

'The sand dunes of Guardamar, and the planting effected on them,

form the subject of an illustrated paper by Mira in vol. 4, no. 1-2,

of the Memorias de la R. Sociedad Espanola de Historia Natural.

Bruck gives an account of wind injury to foliage in Heft 1 of vol.

20, part 2, of the Beihefte zum botanischen Centralblatt.

The biology of a large number of Dicotyledons, from germination

to flowering, is traced and illustrated by Sylvén in the recently issued

vol. 40, no. 2, of the K. Svenska Vetenskapsakademiens Handlingar.

822 THE AMERICAN NATURALIST [Vor. XL

Apogamy is recorded for Dasylirion acrotrichum by Went and

Blaauw in a separate from the Proceedings of February 24 of the

K. Akademie van Wetenschappen te Amsterdam.

The conditions which effect the time of the annual flowering of

fruit trees are analyzed by Sandsten in Bulletin no. 137 of the Uni-

versity of Wisconsin Agricultural Experiment Station.

Britton and Viereck publish an extensive record of the insect visi-

tors of orchard flowers in part 4 of the Report of the Connecticut Agri-

cultural Experiment Station for 1905.

Mattei gives an account of pollination in Cupuliferee (of which

Castanea, Castanopsis, and Pasania are entomophilous) in vol. 4,

no. 1, of the Contribuzioni alla Biologia Vegetale of the Botanical

Institute of Palermo.

Graenicher contributes pollination notes to the April Bulletin of

the Wisconsin Natural History Society.

Photograms of common weed seeds found with grass and clover

seed are given by Garman in Bulletin no. 124 of the Kentucky Agri-

cultural Experiment Station.

An illustrated paper on common weeds and their eradication, by

Wilson, forms Bulletin no. 95 of the University of Minnesota Agri-

cultural Experiment Station.

Notes on charcoal and on rubber and gutta-percha, with especial

reference to the Philippines, form respectively Bulletins no. 2 and 3

of the Bureau of Forestry of those islands.

Altamirano contributes an extensive illustrated paper on “guayule”

to the May Boletín de la Secretaria de Fomento of Mexico.

A number of papers on the constituents of medicinal plants are

published in the recently issued vol. 53 of the Proceedings of the

American Pharmaceutical Association.

A number of northwestern plants are figured, in an economic con-

nection, by Nelson in Bulletin no. 73 of the Washington. Agricultural

Experiment Station.

An attractive little tree book, with half-tone illustrations, by Cor-

revon, has been issued by the Atar Company, of Geneva.

Harshberger publishes on phytogeographic influences in the arts

and industries of American aborigines in the April Bulletin of the

Geographical Society of Philadelphia.

No. 479] NOTES AND LITERATURE 823

A special subscription edition of Bailey and Miller’s Cyclopedia

of American Horticulture has been issued by Doubleday, Page and

Co., of New York, in six volumes bound to match their “Nature

Library.” To what was said of the first edition, from 1900 to 1902,

in the Naturalist need only be added that the present (fourth) edition

contains corrections of detected errors and a conspectus of families

and genera prepared by Mr. Miller, while the number of illustrations.

has been greatly increased.

Under the title Hortus Veitehü, Mr. J. H. Veitch has privately

printed a sumptuous quarto history of the great plant house of which

he is now the head,which is of interest especially for the biographic

sketches of its many explorers and hybridists and the remarkable

list of plants originated or introduced to European gardens by them.

Numerous excellent illustrations add to its attractiveness.

A portrait of Hollös forms the frontispiece to the Journal of Mycology

for May.

A biographie sketch, with portrait, of C. C. Parry, is contributed to

the July number of the Annals of Iowa by C. A. White.

A new relief portrait of Rumphius is figured in Bulletin no. 34 van

het Koloniaal Museum te Haarlem.

The Journals.— Botanical Gazette, May: — Elmer, “New and

Noteworthy Western Plants — III"; Bergen, “Some Littoral Sper-

matophytes of the Naples Region"; House, “New and Noteworthy

North American Species of Trifolium”; Lewis, “The Basidium of

Amanita bisporigera."

Botanical Gazette, June: — Wiegand, “Some Studies Regarding

the Biology of Buds and Twigs in Winter"; Yamanouchi, “ The

Life History of Polysiphonia violacea”; Weiss, ‘The Structure and

Development of the Bark in the Sassafras”; Hill, “The Distribution

and Habits of some Common Oaks."

Botanical Gazette, July: — Jeffrey and Chrysler, “On Cretaceous

Pitoxyla"; Shantz, “A Study of the Vegetation of the Mesa Region

East of Pikes Peak: The Bouteloua Formation"; Nelson, “Con-

tributions from the Rocky Mountain Herbarium — VII”; Peirce,

"Anthoceros and its Nostoc Colonies”; Hill, “Distribution and

Habits of some Common Oaks.” _

824 THE AMERICAN NATURALIST [Vor. XL

The Bryologist, July: — Fink, “Further Notes on Cladonias —

VII"; Collins, “Mounting Mosses, Some Hints"; Hayne, “A List

of Hepatics Collected in the Vicinity of Little Moose Lake....

Herkimer Co., N. Y.”; Smith, “A List of Mosses Collected on the

Adirondack League Club Tract, Herkimer Co., N. Y."; Merrill,

“Lichen Notes no. 3, Chemical Tests in Determining Lichens";

Gilbert, ‘Two Anomalies and a Curious Sight."

Bulletin of the Torrey Botanical Club, May: — Cardiff, “A Study

of Synapsis and Reduction”; Cockerell, “Fossil Plants from Florissant,

Colorado”; House, “Studies in the North American Convolvulacex

paren T

Bulletin of the Torrey Botanical Club, June: — Kirkwood, “The

Pollen-Tube in Some of the Curcubitacez"; Cushman, “New

England Desmids of the Sub-Family Saccoderme.”

Bulletin of the Torrey Botanical Club, July: — Spalding, '' Absorp-

tion of Atmospheric Moisture by Desert Shrubs"; Reed and Smoot,

“The Mechanism. of Seed Dispersal in Polygonum virginianum” ;

Gleason, “The Pedunculate Species of Trillium.”

Fern Bulletin, July: — Klugh, “The Fern Flora of Ontario”;

McNeill, “Botrychium — biternatum" ; Palmer, “Green and Red

Stiped Lady Ferns”; Clute, “The Moonwort”; Lee, “The Hart's

Tongue in Tenn.” ; Davenport, “The Forms of Botrychium simplex" ;

“A Check-list of the North American Fernworts (continued)’’; Druery,

“Lomaria spicant bipinnatum in America."

Iowa Naturalist, January: — Cratty, “Notes on the Iowa Sedges

— I”; Anderson, “Additions to the Flora of Decatur County, Ia.” ;

“The Flora of Lake Wabonsie"; Fitzpatrick, “The Iowa Gentians."

Journal of Mycology, March: — Kellerman, “Job Bicknell Ellis”

(with portrait); Bates, “Rust Notes for 1905"; Saccardo, “ Micro-

mycetes Americani Novi”; Bubak, “Einige neue Pilze aus Nord

America"; Bessey, “Dilophospora alopecuri"; Sumstine, “ Pleuro-

tus hollandianus sp. nov.," Notes on Wynnea americana”; Ricker,

“Second Supplement to New Genera of Fungi Published since the

Year 1900, with Citations and Original Descriptions"; Kellerman,

“Index to North American Mycology," and “Notes from Mycological

Literature — XVIII.” á

Journal of Mycology, May: — Shear, “ Peridermium cerebrum and

Cronartium quercuum”; Morgan, “North American Species of Heli-

No. 479] NOTES AND LITERATURE 825

omyces"; Ricker, “Second Supplement to New Genera of Fungi

Published since 1900, with Citation and Original Description”;

Kellerman, “Index to North American Mycology,’ and ‘Notes

from Mycological Literature — XIX.”

Annals of the Carnegie Museum, July: — Jennings, “ Additions

and Corrections to the List of the Vascular Flora of Allegheny

County, Pa."; “A New Species of Kneiffia"; “A Note on the

Occurrence of Triglochin palustris in Pa."; and “A New Species

of Ibidium (Gyrostachys).”

Journal of the New York Botanical Garden, May: — Britton,

“Recent Botanical Explorations in Porto Rico.”

Journal of the New York Botanical Garden, June: — Murrill, “A

Serious Chestnut Disease"; Britton, “A Large Oak Struck by Light-

ning."

Journal of the New York Botanical Garden, July: — Nash, “The

Flowering of Queen Victoria's Agave."

Journal of the New York Botanical Garden, August: — Maxon,

“Report on a Collecting Trip in Costa Rica"; Shreve, “A Winter

at the Tropical Station of the Garden."

Muhlenbergia, vol. 1, no. 9, July 30: — Osterhout, “Colorado

Notes"; Heller, '*Western Species, New and Old — VI.”

The Yearbook of the U. S. Department of Agriculture for 1905,

recently issued, contains the following articles of botanical interest:

— Webber, “New Fruit Productions of the Department of Agricul- -

ture"; Langworthy, “Fruit and its Uses as Food"; Shamel, “The

Effect of Inbreeding in Plants"; Rolfs, “New Opportunities in

Subtropical Fruit Growing"; True, “Progress in Drug-Plant Culti-

vation."

The Ohio Naturalist, May: — Claassen, “Key to the Species of

Liverworts Recognized in the Sixth Edition of Gray's Manual of

Botany”; Kellerman and York, “Additions to the Flora of Cedar

Point — I.”

The Ohio Naturalist, June: — Schaffner, ‘Terminology of Organs

in Various Conditions of Development”; Jennings, “Additions

to the Flora of Cedar Point — II"; Young, “Key to the Ohio Vibur-

nums in the Winter Condition”; Griggs, “A Diurnal Rotation in

Leaves of Marsilea.”

826 THE AMERICAN NATURALIST [Vor. XL

The Plant World, May: — Andrews, “Some Monstrosities in

Trillium”; Harper, “A December Ramble in Tuscaloosa Co., Ala.” ;

Wiegand, ‘The Passage of Water from the Plant Cell during Freez-

ing.”

The Plant World, June: — Cook, ‘The Disintegrating Influences

of Tropical Plants”; Osterhout, “On the Mountain Top”; Bowman,

“The Chinese Sumach, or Tree of Heaven, — Ailanthus glandulosa” ;

Harris, “ Apparently Imparipinnate Leaves in Cassia."

Rhodora, May: — Lamson-Scribner, “Notes on Trisetum and

Graphephorum”; Fernald, “Some Anomalous Plants of Tiarella

and Mitella”; Knight, “Some Notes on our Yellow Cypripediums” ;

Blanchard, “Two New Species of Rubus from Vermont and N. H.";

Knight, “Some New Records of Maine Plants”; Holm, “Remarks

upon Mr. House’s Paper on Pogonia verticillata.”

Rhodora, June: — Fernald, “ Paronychia argyrocoma and its New

England Representative”; Collins, “New Species, etc., Issued in

the Phycotheca Boreali-Americana”; Sanford, “A Station for As-

plenium ebenoides in Mass.” ; Davenport, “The Apetalous Form of

Arenaria granlandica on Mt. Mansfield”; Fernald, “A New Variety

of Carex interior”; Knight, “Viola nove-anglie in the Penobscot

` Valley."

Rhodora, July: — House, “The Violet Hybrids of the District of

Columbia and Vicinity"; Collins, “Notes on Alge — VII"; Fernald,

. “Some New or Little known Cyperacex of Eastern North America”;

Collins, “Preliminary Lists of New England Plants — XIX" [Bux-

` baumiaces, Georgiaceze, and Polytrichacee].

Torreya, May:—Shreve, “A Collecting Trip at Cinchona”;

Barnhart, “‘Chloronyms’’; Berry, “Pleistocene Plants from Vir-

Torreya, June: — Rusby, “A Historical Sketch of the Development

of Botany in New York City”; Harper, “Some More Coastal Plain

Plants in the Paleozoic Region of Alabama"; Blanchard, “Two

New and Somewhat Anomalous Blackberries”; Eastwood, “The

Earthquake and the California Academy of Sciences”; Mackenzie,

“ Ranunculus sicejormis” ; House, “A Note upon Ipomea cuneifolia.”

Torreya, July: — Rusby, “A Historical Sketch of the Development

of Botany in New York City" (continued); Greene, “Doctor Torrey

No. 479] NOTES|AND LITERATURE 827

and Downingia"; Blanchard, “Two New Dewberries of the hispidus

Group"; Britton, “Galactia odonia”; House, “A New Southern

Convolvulus."

Torreya, August: — Douglas, “The Rate of Growth of Paneolus

retirugis; Rydberg, ‘‘Bassekia or Rubacer"; Rose, ''Terebinthus

macdougali, a New Shrub from Lower California"; House, ‘‘ Notes

on Southern Violets — I.”

University of Colorado Studies, June: — Cockerell, ‘The Fossil

Fauna and Flora of the Florissant (Colorado) Shales”; Ramaley,

“Plants of the Florissant Region in Colorado.”

(No. 478 was issued October 16, 1906)

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THE

AMERICAN NATURALIST

Vor. XL December, 1906 No. 480

THE CAUSES OF EXTINCTION OF MAMMALIA

(Concluded)

HENRY FAIRFIELD OSBORN

Livinc ENVIRONMENT. INFECTIOUS DISEASES AND INSECTS

In his Great Rift Valley (p. 265) Gregory observes that the great

herds of game which roamed over the steppes of South Africa are

being rapidly decreased in size and number. Man no doubt

has played the leading part in the annihilation of the enormous

herds that once thronged Cape Colony. The fact that during the

last few years the game has retreated from the Somali coast into

the interior shows how easily it can be driven from a district.

In South Africa, however, man's influence has probably been

insignificant as compared with natural agencies, lions and disease

— being the leading factors in extermination. Vast herds of the

wild buffalo (Bubalus caffer) were exterminated between 1890

and 1893 by the cattle disease (rinderpest), which also killed off

the gnu and giraffe (op. cit., p. 266). Gordon Cumming * ob-

served, as early as 1855, that “....the goat in many districts is

subject to a disease called by the Boers ‘brunt sickta,’ or burnt

sickness, owing to the animals afflicted with it exhibiting the

appearance of having been burnt. It is incurable; and if the

animals inflicted are not speedily killed, or put out of the way,

the contagion rapidly spreads, and it is not uncommon for a farmer

to lose his entire flock with it. This sad distemper also extends

itself to the fere nature. I have shot hartebeests, black wilde-

1 The Lion Hunter in South Africa, London, 1855, p. 138.

829

830 THE AMERICAN NATURALIST [Vor. XL

beests, blesbucks, and spring-bucks, with their bodies covered

with this disease. I have known seasons when the three latter

animals were so generally affected by it, that the vast plains through-

out which they are found were covered with hundreds of skulls:

and skeletons of those that had died therefrom.”

Aflalo* in his paper “The Beasts that Perish,” has discussed

many of the various causes of extermination and gives disease a

prominent place. Among the Carnivora there are the non-epi-

demic diseases, such as distemper, affecting dogs, foxes, wolves,

cats, and other wild felines. The more rare and sporadic

epidemics claim victims among the Carnivora wholesale. The

prevalence of rabies among foxes was observed on the continent.

from 1830 to 1838 in Switzerland, also in Wiirttemberg and

Baden.

Carnivora are protected by their relatively non-gregarious.

babits. On the contrary, the more gregarious Herbivora offer

much more favorable conditions for the spread of disease. Flem-

ming in his Animal Plagues enumerates 86 epidemics affecting

wild quadrupeds and birds. In the list are diseases affecting

nearly every wild species in Europe and some in the New World,

including the red deer (Cervus elaphus), reindeer (Rangifer ta-

randus), the chamois (Rupicapra tragus), wild hog, also among

the Carnivora, wolves, foxes, bears, among the Rodentia, the hares,

rabbits, and rats. Various forms of tuberculosis account for a

large percentage of death among domesticated animals. Only

the goat enjoys immunity from it. Among animal plagues anthrax

was formerly the most rapid and deadly, and is now perhaps the

least common owing to Pasteur’s discoveries. American zoölo-

gists are familiar with the spread of disease from domesticated

to non-domesticated animals, of the sheep scab, for instance, to

the wild sheep (Ovis montana).

Insects and Injection.— In my opinion the most striking advance

toward a complete theory of the causes of natural extinction has

come from recent discoveries regarding the real nature of the

animal diseases and how they are communicated. Only recently

have we come thoroughly to understand that insects are the most

! The original article has not been accessible to the writer.

No. 480] EXTINCTION OF MAMMALIA 831

active means of introducing and spreading fatal diseases over

great geographical areas and on a vast scale.

Moisture Favoring the Spread of Diseases Carried by Flies.—

The presence of the blood protozoan parasites known as trypano-

somes, combined with certain flies which act as disease carriers,

is in many countries correlated with moist conditions. This is.

especially true of the disease known in India as ‘surra, ' the history

of which was first suspected by Surgeon Major Lewis in 1888.

Extermination of the Equide. Surra.—'l he wide geographical

range of surra and related diseases is significant with reference

to former periods in the history of the Equide. All authors now

agree with Lewis that the disease is carried by flies and coincides

with moist conditions occurring chiefly during or immediately

after heavy rainfalls, though sporadic cases may occur at other

seasons of the year. In the “Emergency Report on Surra" by

D. E. Salmon and C. W. Stiles? this is described as chiefly a wet-

weather disease, invariably fatal to horses and mules, occurring

in other animals, such as camels and elephants, more rarely in

ruminants, and transmissible to goats, sheep, and other mammals.

In India it is said to affect horses, camels, and elephants (p. 18).

It occurs in Burma, Persia, Tonquin, and Korea. In Africa

there is the similar nagana or tse-tse fly disease, more accurately

described below by Bruce? (p. 833). In Algiers, France, and

Spain, the dourine or maladie de coit attacks the horse and ass in

particular, and may be transmitted to certain other animals; it

is attributed to a trypanosome, T. equiperdum. In the Philippines

surra caused the death of 2000 army horses in six months. The

intermediary is a fly, Stomoxys calcitrans. It was also reported

(Curry, 1902) as affecting the carabao (Bos (Bubalus) kerabau),

but according to Lingard ruminants are not particularly suscepti-

ble. An interesting note which may bear upon the origin of colors

in certain quadrupeds is the advice to those in charge of horses

in the Philippines (p. 97): “Avoid light colored animals as much

1 Lewis, T. R. “Flagellated Organisms in the Blood of Animals.” Phy-

siological and Pathological Researches . . . .of the late Timothy Richards Lewis,

ne gos 1888.

S. Dept. of Agric., 1902, Bureau of Animal Industry, bull. 42,

a Science, n. s., vol. 22, no. 558, Sept. 8, 1905, pp. 289-299.

832 THE AMERICAN NATURALIST [Vor. XL

as possible; the darker the animal the safer he appears to be from

the attack of flies.” In this connection we recall the dark color

of the true Bovine. In South America the mal de caderas affects

horses, asses, cattle, hogs, and certain other animals, and is attrib-

uted to the protozoan known as Trypanosoma equinum. It is

distinctively a wet-weather disease, almost completely disappearing

in dry seasons. Asses, swine, and water hogs are said to be

affected, and horses are never known to recover. It is chronic

in course, lasting from two to five months in horses, and from six

to twelve in asses and mules. See Voges ' for fuller details.

Immunity and Adaptation.— Existing conditions among the

large quadrupeds of Africa are especially important because of

the increasing conviction that North American conditions in the

Oligocene, Miocene, and Pliocene are most closely paralleled

in the great upland region of modern Africa, the central life belt

as distinguished from the coast belt.

From these recent discoveries’ it appears that immunity from

disease is one of the most important features of animal adaptation

to environment, and that conversely non-immunity has probably

been one of the potent causes of diminution and extinction. T.

H. Morgan? includes the phenomenon of immunity among the

adaptive processes. He states, as his personal opinion, however,

that certain of these phenomena could not be explained as due to

any selective processes. Similarly Leo Loeb‘ believes that a

large number of instances of acquired immunity cannot be directly

explained as adaptive phenomena.

Variations in Immunity.— There are in Africa diseases fatal

to both wild and domesticated animals, others fatal to domesti-

cated animals to which wild animals are immune. Some to which

all successive generations succumb; others to which immunity

is acquired in the second generation or among ‘natives.’ Still

more remarkable is the fact that both wild and domesticated

1 “Das Mal de Caderas.” Zeitschr. f. Hyg. u. Injectionskrankh., vol. 39,

(3) 13 März, pp. 323-372.

Nature, vol. 72, no. 1872, Sept. 14, 1905, pp. 496-503. Address of Bruce,

ien the Section of Physiology. British Association.

* Evolution and Adaptation, New York and London, 1903.

* "Immunity and Adaptation." Biol. Bull., August, 1905, p. 141.

No. 480] EXTINCTION OF MAMMALIA 833

‘immunes’? may act as reservoirs of disease organisms which

through flies or ticks may be carried to non-immunes. ‘Thus the

wild ruminants of Africa among the Bovide especially, the buffalo

(Bos (Bubalus) caffer), the kudu (Strepsiceros kudu), the wilde-

beeste (Connocheetes) carry about in the fluid portion of their

blood, without themselves suffering any harm, certain protozoan

trypanosomes which are fatal when borne by flies to domesticated

horses (Equidee), dogs (Canidve), and cattle (Bovidee).

Thus, causes favorable either to the genesis of these disease

organisms or to the acquirement of immunity, or to the propaga-

tion and distribution of flies and ticks become matters of prime

interest in relation to extinction.

T'se-tse Fly Disease of Domesticated Equide and Bovide.— The

nagana or tse-tse fly disease of Africa is caused by Trypanosoma

brucei (Plimmer and Bradford); the carrier is the tse-tse fly (Glos-

sina morsitans). Together this trypanosome and its host the

fly render thousands of square miles of Africa uninhabitable and

no horses, dogs, or cattle can venture even for a day into the ‘fly

country.’ After all the non-immune animals of the country have

been killed off and thus no longer exist as sources of infection,

the tse-tse fly spreads abroad out of the ‘fly country’ still giving

rise to the disease. ‘This strange fact led to the discovery of the

fact noted above that many of the immune wild ruminants carry

the same trypanosome (T. brucei) in small numbers in their blood

and thus act as continuous reservoirs of the infection; it is from

them that the fly obtains fresh supplies of the infectious parasite.

A similar parasite also lives in the blood of healthy rats.'

Ticks, the Rapid Spreaders of Disease among Domestic Rumi-

nants.— The Piroplasma parvum is a protozoan which, unlike

the trypanosome, invades the blood corpuscle; it is malignant

with cattle along the greater part of the east coast of Africa causing

what is known as 'east-coast fever’. The infection is usually

transmitted by ticks (most frequently by the brown tick, Rhipi-

cephalus appendiculatus, also by R. simus). Migrating or treking

cattle may carry the ticks many miles a day, and thus spread the

! Analogous to this is the ‘sleeping-sickness’ disease affecting man, which

has spread very rapidly from west to east Africa, carried by a fly, Glossina

palpalis, claiming hundreds of thousands of victims.

834 THE AMERICAN NATURALIST [Vor. XL

disease rapidly over a wide area of country. The larva creeps

on an infected animal, sucks some of its blood, drops off, lies among

the roots of the grass, and passes its first moult becoming a nympha,

then an imago, in either of which latter stages it may infect a

healthy animal by creeping from the grass. The tick is very

hardy and may survive with its infection for a year, but after a

year or fifteen months the infected ticks are all dead and healthy

cattle may enter the field without risk.

Wide Geographical Distribution.— Piroplasma bigeminum simi-

larly causes the ‘Texas’ or ‘red-water fever’ of our Southern

States; it is conveyed by a tick. ‘The germs are latent and the

blood of an animal which has recovered from ‘Texas fever remains

infective; thus apparently healthy cattle may infect imported

susceptible cattle. Such latency has an important bearing upon

the theory of natural extinction as caused by similar germs. ‘The

geographical distribution of this species of Piroplasma is very

| wide; first discovered in North America, it is now epidemic through-

out most of South Africa. Although acquiring immunity, it is the

domesticated native Bovidz which act as reservoirs of the disease

in contrast to the tse-tse fly disease in which the wild Bovide act

as reservoirs. The further fact that the native cattle may become

immune has an important theoretical bearing on the natural

origin of immunity to the tse-tse fly disease on the part of the wild

Bovidee and wild Equide.

Ticks among Equide.— The biliary fever of domesticated

Equide (horses, mules, donkeys) is conveyed by a corpuscle para-

site, Piroplasma equi, which is spread by the red tick, Rhipiceph-

alus evartsi, the infection taken in the nymphal and transferred

in the adult stage. As in the case of Texas fever in cattle, so the

native South African horses become immune to the disease and

are said to be “salted,” but equines which have recovered from

the disease continue to act as reservoirs and remain as sources of

infection throughout their lives. The same is true among the

Carnivora of the Piroplasma canis, spread by the dog tick (Hamo-

physalis leachii). 'The blood of recovered animals remains in-

fective.

Extermination of Wild Ruminants.— The rinderpest or cattle

disease has been the greatest destroyer of the wild African quad-

No. 480] EXTINCTION OF MAMMALIA 835

rupeds (compare Gregory, p. 266). It is fatal to the following

forms: wild buffalo, Bos (Bubalus), the kudu (Strepsiceros kudu),

the sable antelope (Hippotragus niger), the gnu (Connochetes

albojubatus and C. taurina), also in the Philippines to the carabao

(Bos (Bubalus) kerabau). It is fatal to from 90 to 100% of domes-

ticated cattle. Unlike the diseases before considered: (1) the

parasite causing rinderpest is undiscovered, (2) no natural im-

munity is known (methods of artificial immunity were discovered

in 1893), (3) it is distinguished by the ease and rapidity with which

it spreads in all countries, climates, and seasons, being carried

even on the clothes and person of man. It therefore appears

improbable (Bruce) that insects have anything to do with it. It

may be due to a wind-borne bacterial organism.

This disease has been known from time immemorial in Europe

and Central Asia. It is believed by some to have entered the Nile

provinces of 1880, to have reached the Transvaal in 1896, and thus

to have traveled the whole length of Africa in fifteen years. ‘The

spread in Africa has been largely through the wild ruminants.

By analogy we can imagine that a disease affecting the Pleisto-

cene horses of North America may have traveled an equal distance,

namely, from Texas to Patagonia, and destroyed all the South

American Equide.

Local Distribution, Immunity. Horse Sickness.— A very impor-

tant point for the naturalist is the fact that this disease is local in

its distribution, prevailing in low countries and during wet sea-

sons. The infection is not carried into the high country or dur-

ing the dry season.! The parasite causing it is unknown, and is

believed to be ultra-microscopic. It is believed to be carried in

the blood because the 1,000th part of a single drop of blood injected

under the skin of a healthy animal will cause death; some horses

require a larger dose than others, indicating fluctuations in power

of resistance or immunity. Unlike the foregoing diseases it is not

i The same climatic relation is true of the heart-water disease of cattle,

goats, and sheep (Bovidee), which is similar in distribution to the heart-water

horse sickness and is carried by the bont-tick (Amblyomma hebreum), in that

it dies out on the high veldt. Similarly again the catarrhal fever of sheep has

a distribution in South Africa similar to that of horse sickness, and is probably

carried by means of the same night-feeding insect.

836 THE AMERICAN NATURALIST [Vor. XL

endemic or permanent, but occurs in epidemics at intervals of

from ten to twenty years. Its geographical distribution in South

Africa is very wide: in Natal, Zululand, the greater part of Rho-

desia, Bechuanaland, and Portuguese East Africa. Horses placed

in fly-proof shelters even in exceedingly unhealthy places in no

case incur the disease. ‘The particular fly or insect carrier is still

unknown. As in several of the foregoing diseases the infective

power of the blood persists for years.

Natural Origin of Immunity.—For the student of extinction

an important point to note, in connection with ‘horse sickness,’

is that while artificial immunity is thus far undiscovered, degrees

of immunity and of natural immunity sometimes occur. Such

variations in respect to immunity would in a state of Nature lead

to the gradual selection of immune forms and the production of

an immune race.

Summary as to N atural Extinction by Disease

To summarize these remarkable conclusions which we owe to

the labors of Lewis, Koch, Theiler, Kilborne, Smith, Watkins,

Pitchford, and many others, we undoubtedly have here an agency

which must be seriously considered as an occasional if not a fre-

quent cause of extinction of quadrupeds in the past. It will be

noted (1) that in the case of the tse-tse fly disease the wild ru-

minants are the permanent though unharmed reservoirs of the

infective protozoan; (2) that in Texas fever or red-water fever

native immune Bovide are the permanent carriers of the disease

organism; (3) that the ‘rinderpest’ appears to be in an early stage

of its history as a disease in which neither domesticated nor wild

Bovid: have become naturally immune and all the Bovide act

as reservoirs; (4) that in the east-coast fever the infective ticks

survive for a year, while the permanent carriers of the infective

organism are not discovered; (5) that in the biliary fever of domes-

ticated horses, the recovered equines act as reservoirs; (6) simi-

larly again that in ‘horse sickness’ of South Africa the infective

power of the blood in a recovered animal persists for years.

Thus in these diseases we have all the conditions favorable for

the wide distribution of insect-borne diseases which in past times

No. 480] EXTINCTION OF MAMMALIA 837

may have attacked various types of quadrupeds and resulted in

extermination before natural immunity was acquired.

Livina ENVIRONMENT. COMPETING AND HosTILE MAMMALIA

From the struggle with physical environment, with the living

plant and insect environment, we now pass to the struggle with

other mammals.

In the Tertiary of North America we witness:

(a) the rapid multiplication of certain local or native mammals;

(b) the repeated introduction by migration of new mammals,

coming either singly or in waves;

animals.

Even considering the disastrous effects of glaciation and of

desiccation this competition, because it has worked more widely

and over longer periods of time, has been a tremendous agency

of extinction.

Competition of Lower and Higher Types.— Of marsupials in

competition with rodents in Australia Spencer! observes: “In

the case of such smaller marsupials as, for example, species of

Sminthopsis in which the number of young produced at a birth is

from eight to ten and there are at least two broods in each year it

is a matter of considerable surprise that they are not much more

numerous than they are. The explanation is probably associated

with the fact that there is a considerable length of time during

which not only does the capture of the mother result in her destruc-

tion and in that of all the young ones [by birds of prey, for example],

but that during this period she is severely handicapped by not

being able to reach shelter rapidly. It may perhaps be objected

to this that such an animal as a rabbit is handicapped by having

to carry the young ones in utero for a much longer time than the

marsupial does, but anyone who has seen the well-developed,

pouch young ones of a marsupial will realize how much more

cumbersome a burden they are than the uterine embryos of such

an animal as a wild rabbit.”

1 Spencer, Baldwin. “Through Larapinta Land, A Narrative of the Horn

Expedition to Central Australia.” Report of the Horn Expedition to Central

Australia, Sept. 1896, pp. 127-128.

‚838 THE AMERICAN NATURALIST [Vor. XL

As regards this principle, Wallace observes: “There is good

reason to believe that the most effective agent in the extinction of

specles is the pressure of other species, whether as enemies or

merely as competitors." Lyell! observes: “ Extension of the range

of one species alters that of others. In reference to the extinction

of species it is important to bear in mind, that when any region

is stocked with as great a variety of animals and plants as its

productive powers will enable it to support, the addition of any

new species to the permanent numerical increase of one previously

established, must always be attended either by the local extermi-

nation or the numerical decrease of some other species."

Exception must be taken to the sweeping character of these

statements: First, because the eliminating action of a change in

plant lije may have been the real cause of extinction in several

cases where competition with other mammals is the apparent

cause. For example the extinction of the Titanotheriide and

Elotheriide may have been entirely due to changes in vegetation,

rather than to competition with any other Herbivora.

Second, because the survival of the opossums (Didelphiidz)

in North America shows there may be striking exceptions to this

principle.

'The conclusion drawn from Such exceptions is that of Darwin,

namely, that the keenest competitors are the animals of most nearly

similar feeding habits. ‘There are, however, exceptions to Darwin’ S

conclusion also, as the following instances prove.

Destruction of Food Supply by Smaller Browsing Animals.—

‘The enormous changes in the quadruped life of the district en-

circling the eastern and southern sides of the Mediterranean are

popularly attributed to secular changes of climate. Haan shows,

however, that evidence for secular change of climate within the

historic period is insufficient or actually negative. Parts of these

regions were formerly inhabited by some of the larger quadrupeds

which have since disappeared through the agency of man; it is

equally true that the country could not support the life of these

quadrupeds at the present time. There can be little doubt that

the change in soil and vegetation has been indirectly caused by

‘Lyell, C. Principles of Geology, vol. 2, 1872, p. 451.

No. 480] EXTINCTION OF MAMMALIA 839

deforestation of the hills and mountains, and this has largely been

the result of the unrestricted browsing of large herds of sheep and

goats, which has been going on since long before the Christian era.

Even now the goats can be observed in certain parts of Palestine

and Greece destroying the last of the forests and killing the seed-

ling trees. Destruction of the forests led to the washing away of

the soil and to the entire unfitness of the country for the support

of any of the larger Herbivora.'

“The mastodon, for example,” observes Morris needing

great quantities of herbage for its food supply, might, in cases of

severe drought, succumb to the food competition of the rabbit,

or some still more insignificant creature, which, spreading in vast

numbers over the country, devoured the sparse herbage and left

its huge competitor to starve....Thus hosts of Herbivora may

have frequently perished in consequence of an insect assault upon

their food; and numerous Carnivora, thus deprived of their food,

may have similarly perished.”

Especially Intense on Islands.—This great change is paralleled

by the influence of the goats on islands, as cited by Wallace? and

Palmer.*

Palmer (loc. cit.) observes: “Sheep and goats when numerous

‚ are likely to cause widespread injury, particularly in forested

regions. An instructive example of the damage done by goats

is that on St. Helena, described by Wallace? St. Helena is a

mountainous island scarcely 50 square miles in extent, and its

highest summits reach an elevation of 2,700 feet. At the time

of its discovery, about the beginning of the sixteenth century, it

is said to have been covered by a dense forest; to-day it is described

as a comparatively barren rocky desert. This change has been

largely brought about by goats first introduced by the Portuguese

‘Osborn, H. F. “Preservation of the Wild Animals of North America.”

Address before the Boone and Crockett Club, Washington, Jan. 23, 1904, pp.

15-16.

? Morris, Charles. “The Extinction of Species." Proc. Acad. Nat. Sci.

Phila., 1895, p. 254.

5 pnioad Lite, 1880, pp. 280, 283-286.

* Palmer, T. S. “The Danger of Introducing Noxious Animals and Birds.”

Yearbook U. S. Dept. of Agric. for 1898, p. 89.

5 Island Life, 1880, pp. 283-286.

840 THE AMERICAN NATURALIST [Vor. XL

in 1513, and which multiplied so fast that in seventy-five years

they existed by thousands. Browsing on the young trees and

shrubs, they rapidly brought about the destruction of the vegeta-

tion which protected the steep slopes. With the disappearance

of the undergrowth, began the washing of the soil by tropical rains

and the destruction of the forests. In 1709 the governor reported

that the timber was rapidly disappearing and that the goats should

be destroyed if the forests were to be preserved. This advice

was not heeded, and only a century later, in 1810, another governor

reported the total destruction of the forests by the goats.

“The Santa Barbara Islands, and Santa Catalina off the coast

of southern California, and the island of Guadalupe, off the Lower

California coast, are utilized as ranges for goats. All these islands.

are dry and more or less covered with brush, but arborescent

vegetation is comparatively scarce. The goats practically run

wild, and already exist in considerable numbers. As yet the goats

have not been on the islands long enough to cause any serious.

effects on the vegetation, and they may never bring about the ruin

which has been wrought on St. Helena. But it is scarcely possible

for the islands to be grazed by goats for an indefinite length of

time without suffering serious damage.”

Goats, however, do not always enjoy a monopoly of the food

of islands as the case cited above from Linnzeus proves.

Small Browsers in Relation to Carnivora.—In both instances

cited above, unrestricted browsing and rapid multiplication of the

goats have taken place under artificial conditions of protection of

these animals from Carnivora. It is quite possible, however,

that in certain regions under natural conditions the Carnivora.

themselves may have become extinct through epidemics or other

causes, thus promoting the unrestricted multiplication of the

smaller browsing animals so fatal to the vegetation and to the

normal distribution of food supply of a country. The period

during which these changes have taken place in the Orient is a

comparatively short one as compared with the periods of geological

time.

Application to the American Oligocene.—'Thus we see that

the introduction of new forms of dissimilar feeders may completely

disturb the balance of Nature and entirely alter the character

and amount of food supply or even of water supply and of com-

No. 480] EXTINCTION OF MAMMALIA 841

petition in any given region. Rabbits exert a great influence on

the food supply of the marsupial Herbivora of Australia. This

factor of the browsing competition of the smaller Herbivora on

islands is one which, while by no means demonstrated, is a possible

cause of extinction of the larger Herbivora in larger areas and is

worth considering even in relation to the sudden disappearance

of the ‘Titanotheres. For example, the extreme multiplication

of the Oreodonts (Oreodon, Agriochcerus) and horses (Mesohippus),

small browsers which swarmed in herds in the Middle Oligocene

period in the regions of South Dakota and Nebraska, may possibly

have cut off part of the food supply of the Titanotheres.

Application to the Oligocene and Miocene of Europe.— Since

the introduction and unchecked increase of small browsing animals

may in course of a century or a number of centuries — a compar-

atively short period in geological time — effect a profound influence

in a country upon the forests, since sheep and goats are forest

destroyers especially under the artificial conditions where the

increase of these animals is unchecked, and such browsers are

especially destructive of the circumscribed flora of islands, we

should consider the part the smaller browsing animals may have

played during the Tertiary of Europe when so many parts were

archipelagic.

Dwarfed Pliocene and Pleistocene Island Life.—In the islands

of Malta, Cyprus, and Crete, as recently explored by Miss Bate,’

we have fine examples of comparatively recent insulation.

It appears probable that Cyprus became an island first, because:

(1) no submerged bank connects it with the mainland, and the

200-fathom line is reached within a short distance of the coast

line; (2) the terrestrial fauna and avifauna include several distinct

races peculiar to the island, a fact confirmed by Kobelt from his

study of the recent Mollusca. The reduced existing Cyprus

fauna contains a mingling of European and North African forms,

and shows the effects of deforestation in historic times. The

largest animal on the island is the moufflon (Ovis ophion) 25

inches high at the shoulders; yet this is the smallest of all the wild

sheep, and is related to East Persian species.

1 Bate, Dorothea M. A. ‘Pleistocene Mammalia in Crete." Geol. Mag.,

n. s., dec. 5, vol. 2, pp. 193-202, May, 1905.

842 THE AMERICAN NATURALIST [Vor. XL

The affinity of Malta to Sicily is indicated by the occurrence of

two species, Hippopotamus pentlandi and Elephas mnaidriensis,

in the cavern deposits of both islands. The early separation of

Cyprus is indicated by the fact that E. cypriotes and H. minutus

are both more primitive than the Maltese-Sicilian species. Crete

also includes antelope and deer in its Pleistocene fauna.

Pleistocene Extinct Fauna of the Mediterranean Islands

Cyprus Malta Sicily Sardinia

Proboscidea, pigmy

elephants E. cypriotes ` E. melitensis E. lamormoræ

E. mnaidrı- E. mnaidri-

ensis ensis

Artiodactyla, pigmy

hippopotami H. minutus H. pentlandi H. pentlandi

The occurrence of these specifically different though apparently

closely related races of small elephants and hippopotami in widely

separated islands is an instance of independent development

with some divergence from common ancestors.

Introduction of Carnivora

Striking examples of the introduction and competition of Car-

nivora in past and recent times are:

(1) The true Carnivora in competition with the Creodonta of

Europe and North America, followed by the final extinction of

the latter order in the Lower Oligocene.

(2) The true Carnivora in South America in the Middle Pliocene.

At this time the Canidæ and two destructive types of Felidæ, the

sabre-tooths (Machærodontinæ) and the true cats (Felinæ), sud-

denly appeared; they entered a faunal region which, subsequent

to the extinction of the marsupial Carnivores (Thylacinidæ) in

the Oligocene, had been entirely free from Carnivora.

(3) The dingo (Canis dingo), in the Australian mainland,

followed by the extinction of the Tasmanian wolf (Thylacinus)

and devil (Sarcophilus), animals which survive only in Tasmania.

(4) The mongoose (Herpestes). in various countries.

In each instance intelligence, ferocity, and facility in change of

habit have played an important part. The Carnivora in relation

No. 480] EXTINCTION OF MAMMALIA 843:

to the balance of Nature, the food supply, the young of the Herbi--

vora is our special inquiry.

Smaller Carnivora and the Balance of Nature. — T. S. Palmer!

has given a striking summary of the influence of the mongoose:

“The common mongoose of India (Herpestes mungo or H.

griseus)....is a well known destroyer of rats, lizards, and snakes,

and was introduced into Jamaica....for the purpose of ridding:

cane fields of rats. . . . Various remedies were tried, but apparently

with little success, until in February, 1872... .nine individuals

of the mongoose, four males and five females, from India, were-

introduced. ‘These animals increased with remarkable rapidity,

and soon spread to all parts of the island, even to the tops of

the highest mountains. A decrease in the number of rats was

soon noticeable. . . . The mongoose increased, and as the rats dimin--

ished, its omnivorous habits became more and more apparent.

It destroyed young pigs, kids, lambs, kittens, puppies, the native

“coney’ or capromys poultry, game, birds which nested on or near-

the ground, eggs, snakes, ground lizards, frogs, turtles’ eggs, and

land crabs. It was also known to eat ripe bananas, pineapples,

young corn, avocado pears, sweet potatoes, cocoanuts, and other

fruits. Toward the close of the second decade the mongoose,

originally considered very beneficial, came to be regarded as the

greatest pest ever introduced into the island. Poultry and domes-.

ticated animals suffered from its depredations, and the short-tailed

capromys (Capromys brachyurus), which was formerly numerous.

became almost extinct except in some of the mountainous districts.

The ground dove (Columbigallina passerina) and the quail dove-

(Geotrygon montana) became rare, and the introduced bobwhite,

or quail, was almost exterminated. The peculiar Jamaica petrel.

(Estrelata caribbea), which nested in the mountains of the island,.

likewise became almost exterminated. Snakes, represented by

at least five species, all harmless, and lizards, including about

twenty species, were greatly diminished in numbers. ‘The same

thing was true of the land and fresh-water tortoises and the-

marine turtle (Chelone viridis), which formerly laid its eggs in

1 Palmer, T. S. “The Danger of Introducing Noxious Animals and Birds.’

Yearbook U. S. Dept. of Agric. for 1898, pp. 93, 94.

844 THE AMERICAN NATURALIST [Vor. XL

abundance in the loose sand on the north coast. ‘The destruction

of insectivorous birds, snakes, and lizards was followed by an in-

crease in several injurious insects, particularly ticks, which became

a serious pest, and a Coccid moth, the larvee of which bore into

the pimento trees.”

Carnivorous Animals Directly Hostile.— The question as to

how far the mammals of prey have caused the extinction at various

times of various forms of quadruped life is widely disputed.

Morris! observes: “So far as existing evidence goes, then, it seems

probable that hostile aggression, while it may have occasionally

been an indirect, has rarely been the direct cause of the extinction

of species.” The similar opinion expressed to the writer by Dr.

D. G. Elliot that no wild animal causes the extinctionof another

wild animal is probably true (1) of undiminished herds, (2) of

cases where carnivores and quadrupeds have evolved together and,

as in the case of the modern battleship, modes of defence have

evolved simultaneously with modes of attack.

In this connection, however, we must consider the Carnivora

as one of the causes of final extinction of diminished groups of ani-

mals which are struggling to maintain themselves against adverse

conditions of (a) physical environment, droughts, or cold, (b)

changing food supply, (c) competition with other quadrupeds, (d)

epidemics.

The above opinions (of Morris and Elliot), therefore, do not

hold good (3) of diminished herds, which are unable adequately to

defend their young, or (4) of cases where newly introduced Carni-

vora find quadrupeds unprovided with adequate means of defence,

as in the South American invasion from North America in the

upper Pliocene.

INTERNAL CAUSES OF EXTINCTION

Environment and life (including heredity and ontogeny) are

always reciprocal. Having considered the causes of extinction

which originate in the environment let us pass to those which

originate in a lack of internal adaptation and adaptability.

1 “The Extinction of Species.” Proc. Acad. Nat. Sci. Phila., June, 1895,

pp. 253-263.

No. 480] EXTINCTION OF MAMMALIA 845

IMPORTANT DIFFERENCES BETWEEN THE EFFECTS OF INTERNAL AND

EXTERNAL CAUSES

Summarizing the external causes we observe:

(1) That in large part they originate with cosmic changes, or

with changes in the earth itself, in the elevation or depression,

extension or contraction of the land and water areas. From these

result progressive heat or cold under both moist and dry conditions,

progressive moisture and desiccation, consequent changes of soil,

vegetation, forestation, water supply. Also the introduction of

new food competitors or enemies, of new insect pests and new

diseases.

(2) Under these changed conditions we observe that the ex-

tinction of species and genera has repeatedly occurred on a very

large scale. Secular desiccation in different periods of the Tertiary,

but chiefly toward the late Pliocene, was quite as fatal as the

Glacial Period.

(3) A distinctive feature of such extinction, originating in

external causes, is that it often affects the fit and unfit alike, the

adapted and inadapted; it often destroys rather than improves

a fauna. This was certainly the case with the glacial extinction in

North America and Europe.

(4) On the contrary, the extinction, originating in internal

causes, 1. e., in relative internal fitness or unfitness, often improves

a fauna by eliminating the least adapted members.

(5) A further distinction is that external causes have usually

acted locally or on certain parts of the earth’s surface, leaving a

part of the fauna to survive elsewhere. The elimination of the

Equide and Proboscidia in North and South America, for example,

did not hinder their survival in the Old World.

(6) Internal causes, relative inadaptation or unfitness, have,

on the contrary, acted simultaneously all over the world, for exam-

ple, in the elimination of the great orders of Creodonta, Ambly-

poda, and Condylarthra during the Eocene period.

SURVIVAL OR EXTINCTION VALUE OF ORGANS

Paleontology affords positive evidence that structural or func-

tional inadaptations have been primary causes of extinction at all

times but chiefly during periods of external change.

846 THE AMERICAN NATURALIST [Vor. XL

(1) Since the publication of The Origin of Species naturalists

have disagreed as to one of Darwin's main propositions, namely,

that the struggle for existence is so intense that variations adaptive

or inadaptive, no matter how slight, will tend respectively toward

survival or elimination. This raises the question of the modes

of evolution, of character or organ building, in mammals, which is

treated elsewhere.

(2 Whatever may be true as to the above feature of the

selection theory, there is a general consensus of opinion that ani-

mals which present the highest adaptive combination of favorable

characters, of fully formed organs, and the highest adaptability

or capacity of favorable change of habit or structure, will tend to

survive.

(3) Similarly there is a consensus, from certain repeatedly

observed facts in paleontology that in varietal, specific, generic,

jamily selection, not only adaptive or inadaptive combinations

of characters but also single fully formed organs, such as the brain,

the limbs, and the teeth, have in course of time been the causes

of selection or extinction, partly in connection with changes of

environment, partly because inherently adaptive or inadaptive.

(4) Thus we make the generalization that in certain cases

extreme bulk, extreme specialization, the development of certain

dominant characters, have led to extinction; that large-brained

have replaced small-brained types; that certain types of teeth

or certain types of limb and foot structure have simultaneously

over large parts of the world been found wanting and thus proved

fatal to their possessors.

These are the general lines of thought which have been followed

by many authors since Darwin first directed our attention to this

subject. It is necessary, however, to look into these causes some-

what more critically since many of them have been assumed without

oof.

7 nadaptive Foot and Molar-Tooth Structure — Waldemar Kow-

alevsky, the Russian paleontologist, was one of the pioneers in

this line of reasoning. He observed in his great monograph *

1“Monograph der Gattung Anthracotherium Cuv. und Versuch einer

natürlichen Classification der fossilen Subs " een id,

vol. 2, 3. y.

No. 480] EXTINCTION OF MAMMALIA 847

(1873, p. 152) the extinction of all Artiodactyla with an inadaptive

foot structure and inadaptive grinding teeth as follows: Upper

Eocene, Xiphodon, Anoplotherium, Diplopus; Oligocene, Hyopo-

tamus, Anthracotherium, Entelodon. He pointed out that the

inadaptation of the foot in these animals consisted of a mechanical

defect in the manus (3d metacarpal not spreading above to articu-

late with the trapezium as in the ‘adaptive’ manus of the pig and

hippopotamus, see Taf. 7), and that the inadaptation in the grinders

consisted of the persistent short or brachyodont crowns, buno-

selenodont and bunodont, composed of partially rounded cones.

These feet being mechanically weak in the function of the carpals

and metacarpals were incapable of the elongation into cannon

bones — a cursorial or speed adaptation which saved the lives of

the adaptively reduced Artiodactyls. "These short teeth were by

his theory not adapted to a supposed change of vegetation from

softer herbage to harder Graminez. His paleozoölogical sup-

position that such a change of food occurred was independently

confirmed by the paleobotanists Saporta and Marion. His con-

clusion as to extinction (which was very original at the time) has

since been abundantly confirmed by subsequent observations of

the extinction of all forms of quadrupeds with these inadaptive

types of short-crowned grinders both in North America and in

India.

This generalization is noteworthy also as bearing upon the

extinction of the Titanotheres (Oligocene) and Chalicotheres

(Upper Miocene) types, both of which possess short-crowned

bunoselenodont molars.

Inadaptation of the Titanothere Grinding Teeth.— It has since

been recognized by every author who has written upon these

animals that the relatively short crowns of the so called buno-

selenodont or combined cone-and-crescent pattern of grinding

teeth, were adapted to browsing on coarse and soft rather than fine

and hard kinds of food. Thus Lucas observes: “....it is easy

to see from a glance at their large, simple teeth that these beasts

[Titanotheres] needed an ample provision of coarse vegetation

and as they seem never to have spread far beyond their birthplace, .

! Animals oj the Past. Svo, New York, 1901, p. 222. :

848 THE AMERICAN NATURALIST [Vor. XL

climatie change modifying even a comparatively limited area

would suffice to sweep them out of existence.”

In the summary of the tooth characters of the Titanotheres

we have shown how Nature was apparently making an effort

to develop a long or hypsodont crown ‘by the elongation of the

ectoloph on the outer side of the superior grinding teeth, and

secondly how this effort was apparently futile because of the

separate rise or development of the inner or cone side of the tooth

and the absence of a transverse crest. Such a tooth is half hypso-

dont and half brachyodont. It does not favor longevity because

it is soon worn off.

A cul de sac in evolution is an avenue from which there is no

escape. This was reached in the teeth of the Titanotheres not,

as in many other animals by a great sacrifice of numbers in the

specialization of the teeth, but by a sacrifice of parts; the inter-

mediate tubercles were lost and the internal tubercles were isolated.

It is noteworthy that every animal experimenting with teeth of

this kind (Anoplotheriide, Anthracotheriide, | Chalicotheriidze)

became extinct; there was no further mechanical progress or

perfection possible, hence the cul de sac. At this point an animal

is at the mercy either of its competitors or of a change of vegetation.

We conclude from the extinction of the large-toothed Titanothe-

rium ingens that it was not the size of the teeth but the mechanical

pattern which was inadaptive.

While it appears that the Titanotheres with their immense bodies

were poorly equipped for the competition for food, and would

have been seriously affected by any change of climate which greatly

altered the general vegetation, especially if it resulted in an increase

of grasses and a decrease of the softer plants, we must record the

fact that the Elotheres, with still less effective teeth, passed through

exactly such a crisis (if it occurred), that soon afterward they

began a very rapid increase in size, and that they survived to a

much later geological period (Lower Miocene).

Regarding the influence of the teeth as chief factors in extermi-

nation there is the strong collateral evidence for Kowalevsky's

theory as described above, that since all bunoselenodont quad-

rupeds whether belonging to the Artiodactyla or Perissodactyla,

disappeared either during the Oligocene or early Miocene period

No. 480] EXTINCTION OF MAMMALIA 849

in all parts of the world, the possession of this type of tooth was

the primary cause of extinction.

Of all the possible causes of extinction of the Titanotheres this

seems to be the one which has the strongest collateral support.

Yet the suddenness of 'litanothere extinction seems to require

the existence of contributory causes.

Relation of Molar-Tooth Structure to Longevity and Reproductive

Power.— There is obviously a direct correlation between longevity

and fertility with hypsodontism, or the elongation of the crowns of

the grinding teeth, which enables an animal to live a great many

years. Elephants, according to Darwin’s calculation, although

slow-breeding animals, with the aid of their extremely long-

crowned teeth live 90 years and produce at least three pair of

young. Horses with their long-crowned teeth, living to the age

of twenty-five years and foaling every year would produce twenty-

two young.

In contrast such a titanothere type as Pal®osyops, with its short-

crowned teeth, would live a comparatively short period and pro-

duce comparatively few young. ' In the long run this relation of

longevity to reproduction would tend to replace the races with

short-crowned teeth by those with long-crowned teeth.

Theoretically this law might be one of the means of explaining

the early dying out of the short-crowned, broad-skulled genus

Palzosyops, if it were not for the contradictory fact that the short-

crowned Manteoceras survived and that the long-crowned Tel-

matherium became extinct.

Feet and Limbs.— Like the teeth, the feet of the Titanotheres

were practically stationary in development. Just as the Oligocene

tooth is an enlarged duplicate of the Eocene tooth, so the Oligocene

titanothere foot is an enlarged duplicate of the Eocene foot.

Since the remains of these animals are found chiefly in coarse

river channel deposits, there is no geological evidence that these

animals suffered from a scarcity of water. ‘The floods, however,

may have been periodic with intervals of drought and it may be

imagined that under changing conditions of plant life the titanothere

feet and limbs were not adapted to long excursions for food en-

forced during the annual dryer periods, as compared with other

quadrupeds. But the Titanotheres were certainly not far inferior

850 THE AMERICAN NATURALIST [Vor. XL

travelers to the contemporary rhinoceroses, and were equal to the

modern elephant type. This therefore may be considered as a

contributory cause rather than as one of the chief causes of titano-

there extinction. |

THE INADAPTATION OF LARGE SIZE

There is a widespread belief, which is not borne out by the

facts, that bulky animals have tended to disappear first.

Thus Owen, although as late as 1877 ' disposed to attribute the

extinction of the large mammals of Australia to the agency of man,

advanced the theory? of the disadvantages of bulky size under

changed conditions. “ In proportion to the bulk of a species is

the difficulty of the contest which, as a living organized whole,

the individual of such species has to maintain against the

surrounding agencies that are ever tending to dissolve the vital

bond, and subjugate the living matter to the ordinary chemical

and physical forces. Any changes, therefore, in such external

conditions as a species may have been originally adapted to exist

in, will militate against that existence in.a degree proportionate,

perhaps in a geometrical ratio, to the bulk of the species. If a

dry season be gradually prolonged, the large Mammal will suffer

from the drought sooner than the small one; if any alteration of

climate affect the quantity of vegetable food, the bulky Herbivore

will first feel the effects of stinted nourishment.....The actual

presence, therefore, of small species of animals in countries where

larger species of the same natural families formerly existed, is not

the consequence of any gradual diminution of the size of such

species, but is the result of circumstances which may be illus-

trated by the fable of the ‘oak and the reed’; the smaller and

feebler animals have bent, as it were, and accommodated themselves

to changes which have destroyed the larger species.”

Morris? observes: “....One tendency, which has particularly

Researches on the dot Remains of the Extinct Mammals of Australia.

RR eT 1877, pp. i

ns. Zool. Soc. Lewin va 4, 1850, p. 27.

3 Morris, Charles. “The Extinetion ea Species." Proc. Acad. Nat. Sci.

Phila., 1895, p. 254.

No. 480] EXTINCTION OF MAMMALIA 851

manifested itself in herbivorous animals, has frequently led di-

rectly to their destruction. This is the tendency to increase in

size through the double influence of abundance of food and little

waste of tissue through exertion. In the sluggish grass-eaters,

dwelling on plains covered with rich herbage, or leaf and twig

eaters in tropical forests, the nutritive agencies are in excess of

those of waste, and these animals seem always to have tended to an

increase in size, until those of least exertion and greatest powers of

obtaining food became enormous in dimensions. An example of

the same kind among the Carnivora is the Greenland whale, which,

while feeding on minute forms, obtains them in enormous quan-

tities with little muscular exertion, and has in consequence become

of extraordinary dimensions... .”’

Bulk not Intrinsically F ai The extinction of a lies

quadruped attracts more attention but we recall the fact (a) that

the small Condylarthra became extinct before the large Ambly-

poda, (b) that many families of relatively small Artiodactyla

and Perissodactyla became extinct at the same period as the

very large Titanotheres; (c) that the relatively small Mylodon

disappeared as early as the large Megatherium; (d) that the

extinction of the mammoth in the northern hemisphere during or

after the glacial epoch attracts attention because of the animal’s

large size, but as shown, many other quadrupeds vastly inferior

in size disappeared at the same time.

(2) The survival of animals which have been constantly in-

creasing in size from the Eocene to the present time may be cited

as proof that bulk is not a cause of elimination per se. The wild

horses, rhinoceroses, many ruminants, bears, and probably the

whales have now attained the maximum size. The African ele-

phant is practically as large as any of the extinct species. Both

the elephant and the white rhinoceros (which would have survived

in large numbers but for the purely accidental interference with

the order of Nature by man) are perfectly adapted in these two

respects

(3) Bulk i is fatal under certain changes of environment where

not correlated with an adequate feeding mechanism, with adequate

defensive powers, adequate fertility, and adequate defense and care

of the young.

852 THE AMERICAN NATURALIST [Vor. XL:

But the absence of these powers is almost equally jatal to small ani-

mals.

Bulk must therefore be considered in relation to (1) disadvan-

tage of the large amount of food required by a large animal, which

is offset by the advantage that many large animals can travel long

distances; (2) diminished birth rate, which is a characteristic of

large animals, is a point to be noticed; as a rule, the larger the

animals, the fewer the young, and the less able a species would be

quickly to regain numerical strength after some widespread

diminution in number; (3) by the fact that the diminished birth-

rate is offset by longevity and power to protect young from enemies.

“The elephant," observes Darwin, “is reckoned to be the slowest

breeder of all known animals, and I have taken some pains to

estimate its probable minimum rate of natural increase: it will

be under the mark to assume that it breeds when thirty years old,

and goes on breeding till ninety years old, bringing forth three

pair of young in this interval; if this be so, atthe end of the fifth

century there would be alive fifteen million elephants, descended

from the first pair.’’*

A pplication to the Titanotheres.— The bulk of the Titanotheres,

which exceeded that of any other land quadrupeds, excepting only

the more modern elephants, may have been a serious drawback

under changing conditions of vegetation; but as noted"above the

extinction of the huge 'Titanotheres was no more sudden or myste-

rious than that of the slender Hyracodontid: and Lophiodontide,

or of the Amynodontidze —all contemporaries of the Titanotheriidee-

and vastly inferior in size.

It is important to note that whereas in the elephant the dimin-

ished birth rate is offset by longevity this was not the case in the

Titanotheres which with their very short-crowned teeth were rela-

tively short-lived animals.

Bulk, Slow Breeding, and Variation.— The following argument

by Wallace receives no support from paleontology. ‘There is,

however, another cause for the extinction of large rather'than small

animals whenever an important change of conditions occurs, which

has been suggested to me by a correspondent, but which has not,

! Darwin, C. Origin of Species, p. 63, ed. of 1860.

? Mr. John Hickman of Desborough.

No. 480) EXTINCTION OF MAMMALIA 853

I believe, been adduced by Mr. Darwin or by any other writer

on the subject. It is dependent on the fact, that large animals

as compared with small ones are almost invariably slow breeders,

and as they also necessarily exist in much smaller numbers in a

given area, they offer far less materials for favourable variations

than do smaller animals: In such an extreme case as that of

the rabbit and elephant, the young born each year in the world

are probably as some millions to one; and it is very easily conceiv-

able that in a thousand years the former might, under pressure of

rapidly changing conditions, become modified into a distinct spe-

cles, while the latter, not offering enough favourable variations to

effect a suitable adaptation, would become extinct.” '

Mr. C. W. Andrews? has recently (1903) revived this argument

that the lengthening of the time taken to attain sexual maturity

may affect the rate of evolution, and under changed conditions

—_ a rapid rate of evolution is essential may cause extinction.

..In many Ungulates this increased longevity is indicated

T various modifications of the teeth, tending to give them a longer

period of wear: generally this end is attained by the increasing

hypselodonty of the cheek-teeth. A necessary consequence of

the longer individual life will be that in a given period fewer

generations will succeed one another, and the rate of evolution

of the stock will therefore be lowered in the same proportion. If

now the conditions of life undergo change, the question whether

a given group of animals will survive or become extinct will depend

upon whether it can undergo sufficiently rapid variation to enable

it to avoid getting so far out of harmony with its surroundings

that further existence becomes impossible. It seems to follow then

that the smaller animals, in which the generations succeed one

another rapidly, will have a better chance of surviving than the

larger and more slowly breeding forms, which at the same time

will be still further handicapped if, as is usually the case, they are

more highly specialized than the smaller forms, and therefore have

a more restricted range of possible variation."

ı Wallace, A. R. Geographical Distribution of Animals, vol. 1, pp. 158-159.

? Andrews, C. W. “Some Suggestions on Extinction." Geol. Mag., dec. 4,.

vol. 10, no. 463, January, 1903, p. 2.

854 THE AMERICAN NATURALIST [Vor. XL

As against these purely hypothetical considerations paleontology

shows that during Pliocene and Pleistocene times the slow-breed-

ing Proboscidia evolved quite as rapidly, if not more rapidly,

than the rapid-breeding Rodentia.

THE INADAPTATION OF EXTREME SPECIALIZATION

Extreme Specialization.— Specializations among the quadru-

peds take many forms: the loss of parts which under changing

conditions might be useful. In the case of the Titanotheres the

diminished size of the cropping teeth, which are either degenerate

or wanting, is an instance. The animals while capable of browsing

were incapable of grazing, so far as we can infer from the general

presence of well adapted paired or single cropping teeth in the

surviving ruminants and horses. It may be said that the Titano-

theres had lost all cropping power through the degeneration,

simplification, or absence of the incisor teeth.

Survival of the Unspecialized.—'This is a general but not

universal principle. Cope observes:

“Agassiz and Dana pointed out this fact in taxonomy, and I

expressed it as an evolutionary law under the name of the ‘ Doctrine

of the Unspecialized.' This describes the fact that the highly

developed, or specialized types of one geologic period have not been

the parents of the types of succeeding periods, but that the descent

has been derived from the less specialized of preceding ages. No

better example of this law can be found than man himself, who

preserves in his general structure the type that was prevalent

during the Eocene period, adding thereto his superior brain-

structure.

“The validity of this law is due to the fact that the specialized

types of all periods have been generally incapable of adaptation

to the changed conditions which characterized the advent of new

periods. Changes of climate and food consequent on disturbances

of the earth's erust have rendered existence impossible to many

plants and animals, and have rendered life precarious to others.

Such changes have been often especially severe in their effects on

species of large size, which required food in large quantities. The

No. 480] EXTINCTION OF MAMMALIA 855

results have been degeneracy or extinction. On the other hand

plants and animals of unspecialized habits have survived." !

Dominant Characters.— Characters which have reached an

extreme stage so as to demand a larger share of the sum total of

bodily nutrition than their general or apparent utility justifies

may be known as dominant organs. They appear to violate the

law of economy of growth, or the maximum combination of favor-

able characters by the subservience of each part to the whole.

The great horns of the Titanotheres, the tooth of the narwhal,

the tusks of the Babirussa, the horns of the Irish deer, Megaceros,

the tusks of the mammoths, E. primigenius, E. columbi, and E.

imperator, are cases in point. The tusks of the elephants, however,

serve a variety of useful purposes.

Overdevelopment of such organs has long been considered

among the possible causes of extinction. The overdevelopment

itself has recently been explained by F. B. Loomis? as follows:

The above are selected examples in which a feature once

useful has been developed beyond its maximum utility. Many

others equally striking might be cited, the explanation of all of

which is extremely difficult unless such a factor as momentum is

called in. In the light of this factor, however, a logical and ap-

parent cause is found. Momentum also explains why a character

that originated in accordance with the environment develops so

rapidly, and why, when an animal had reached adjustment to its

surroundings, it still goes on beyond a perfect adjustment. It

may be laid down as a rule then that a variation started along any

line tends to carry that line of development to its ultimate, being

driven by momentum. If the feature is detrimental the group

dies out; if, however, it is merely a minor feature it makes a handi-

cap. A line of development may be stopped and its momentum

overcome but the tendency is to keep right on.”

Selection of Useless Dominant Organs.— Another explanation

may be offered for certain male dominant characters, namely,

that by sexual selection or competition between the males for

females, characters are precociously or overdeveloped, which are

! Cope, E. D. Primary Factors of Organic E volution, 1896, p. 173.

? Loomis, F. B. ‘‘Momentum in Variation.” Amer. Nat., vol. 39, 1905,

p. 843

856 THE AMERICAN NATURALIST [Vor. XL

of little use in general selection and competition with other animals.

Thus in the case of horns, of tusks, and of canines, by favoring

the males in which they are most strongly developed they cause

an incidence of selection on characters which are useful in sexual

selection only.

Extreme specialization in several members of the titanothere

family took the form of dominance of the horns. As we have

seen, the horns first appeared alike in both sexes as rudiments or

small horns but gradually they became male characters, and were

undoubtedly of advantage to the males in their sexual combats

for the possession of the females. ‘Thus a constant selection of

the individuals with the largest horns may have been in process.

This incidence or main emphasis of natural selection on characters.

which were useless for feeding purposes may have been the cause

of the non-evolution of the teeth.

The force of this generalization is, however, weakened by the

fact that in other Titanotheres, such as the genera "'itanotherium

and Megacerops, the horns were relatively small, yet these animals

became extinct at the same time as the large-horned genera,

Brontotherium and Symborodon.

Psycuic OR CEREBRAL INADAPTATION

Brain.— Under temporary or prolonged changed conditions

of life, intelligence and instinct are matters of first importance in

relation to quickness, alertness, adaptability to new conditions.

Animals differ enormously in this regard. On our western plains

horses by their resourcefulness save their lives where cattle perish.

The paleontologist knows nothing of these psychic qualities,

he can only judge the powers of an extinct animal by examining

the intra-cranial cast which often reproduces the external form

of the brain with great fidelity. The chief measure of the capacity

of extinct animals is indicated by:

(1) absolute size and weight of the brain;

(2) development of the convolutions;

(3) proportionate size of the frontal lobes of the cerebrum;

(4) ratio of brain weight to body weight.

Lortet was the first to establish the law of the progressive cere-

bral development of the Tertiary mammals.

No. 480] EXTINCTION OF MAMMALIA 857

In 1884 Marsh briefly considered the brain question in relation

to the extinction of the Titanotheres or Brontotheriide. He ob-

serves (p. 190): “ The small brain, highly specialized characters,

and huge bulk, rendered them incapable of adapting themselves

to new conditions, and a change of surroundings brought extinc-

tion." Again (p. 190): “The Dinocerata, with their very diminu-

tive brain, fixed characters, and massive frames, flourished as

long as the conditions were especially favorable, but with the first

geological change, they perished, and left no descendants." In

discussing the brain, especially after referring to the general law

of brain growth (7. e., evolution) during the Tertiary period, he

states: i

“To this general law of brain growth two additions may now be

made, which briefly stated are as follows: (1.) The brain of a

mammal belonging to a vigorous race, fitted for a long survival,

is larger than the average brain, of that period, in the same group.

(2.) The brain of a mammal of a declining race is smaller than

the average of its contemporaries of the same group.” *

As above noted the chief advantages of brain capacity are un-

doubtedly in relation to adaptability of habit, resourcefulness in

times of exposure, alertness in avoiding new dangers to which the

young may be exposed, enterprise in seeking new habitat, quali-

ties which should be more fully considered under the law of adap-

tive variation and the evolution principle of organic selection.

ARRESTED VARIATION

Brocchi on the Dying Out of Species.— An Italian geologist,

Brocchi,? the author in 1814 of an able work on the fossil shells

of the sub-Apennine hills, endeavored to imagine some regular and

constant law by which species might be made to disappear from

the earth gradually and in succession. The death, he suggested

of a species might depend, like that of individuals, on certain

peculiarities of constitution conferred upon them at their birth;

and as the longevity of the one depends on a certain force of vitality,

ı Marsh, O. C. “Dinocerata, an Extinct Order of Gigantic Mammals.”

Mon. U. S. Geol. Surv., vol. 10, Washington, 1884, p. 59.

2 Brocchi. Conch. foss. subap., vol. 1, 1814.

858 THE AMERICAN NATURALIST [Vor. XL

which, after a period, grows weaker and weaker, so the duration

of the other may be governed by the quantity of prolifie power

bestowed upon the species which, after a season, may decline in

energy, so that the fecundity and multiplication of individuals

may be gradually lessened from century to century, "until that

fatal term arrives when the embryo, incapable of extending and

developing itself, abandons, almost at the instant of its formation,

the slender principle of life by which it was scarcely animated,

and so all dies with it."* Lyell opposed this doctrine on the ground

that there is seldom evidence of physiological deterioration in the

last representatives of a species.

This idea of self extinction, as applied to a theoretical arrest of

variation was expressed in another form by Darwin and Wallace

and has been recently revived.

The Limiting of Variation.—'The theoretical importance as-

signed to the limiting of variation (independently of environment)

as a cause of extinction depends partly upon one’s theoretical

opinions as to the modes of evolution. In the citations made above

from Darwin (p. 852), Wallace (p. 852) and Andrews (p. 853) the

theoretical view is taken that since (1) a limitation or cessation of

fortuitous variation would cut off material for improvement

through selection, (2) a fixed or non-adaptable type would arise and

(3) extinction would follow.

Similarly Mr. C. B. Crampton (as cited by C. W. Andrews)?

suggests an inherent cause of extinction as follows: “....Ina

recent paper by Mr. C. B. Crampton (Proc. Roy. Phys. Soc.

Edinburgh, vol. xiv, p. 461) a possible inherent cause of extinction

is suggested. It is impossible to do justice to this interesting

paper in a short note, but the gist of the argument seems to

be as follows:— In the original unicellular organism the possi-

bilities of variation are almost infinite, but as soon as evolution

along any line begins, these possibilities are restricted, and become

more and more so the more highly specialized the animal is; in

short, the potential variation of an organism becomes less and less

as specialization advances. Furthermore, under the influence of

1 Lyell, Charles. vince of Geology, vol. 2, 11th ed., 1892, p. 270.

? Andrews, C. W. “Some Suggestions on Extinetion, " Geol. Mag., dec.

4, vol. 10, no. 463, p. 1, January, 1903.

No. 480] EXTINCTION OF MAMMALIA 859

natural selection, in each generation the individuals which tend

to vary in the same direction will survive, while at the same time,

as already pointed out, their capacity for variation becomes more

and more restricted. The consequence of this will be that the

more highly specialized any stock becomes, the more the individ-

uals composing it will come to resemble one another, until at

length the same results as arise from close inter-breeding, viz.,

weakening of the stock, and, finally, extinction, may follow.”

This is purely a question of evidence and all the evidence we

can muster is negative. Invertebrate paleontologists cite cases of

extinction being preceded by an efflorescence of new structures.

Among the Vertebrata no evidence has been adduced of extinc-

tion being preceded by an arrest of variation, 7. e., of evolution.

On the contrary extinction often occurs at the high tide of change

and not after a prolonged period of stability.

CONCLUSION

'The chief induction which can be made from this extensive

survey of the causes of extinction seems to be this: following the

diminution in number which may arise from a chief or original

cause, various other causes conspire or are cumulative in effect.

From weakening its hold upon life at one point an animal is

endangered at many other points.

THE ALPINE FLORA OF COLORADO

T. D. A. COCKERELL

In 1881 (Bull. U. S. Geol. and Geogr. Surv. Terr., vol. 6, no. 1)

Gray and Hooker gave a list of the alpine plants of the Rocky

Mountains: 184 species, of which 102 extended to the arctic or

subarctic regions. Since that time, our knowledge has greatly in-

creased, but the records have been scattered in many publications,

and no summary has been available. The appearance of a new

Flora of Colorado, written by Dr. P. A. Rydberg and issued by the

‘Colorado Agricultural Experiment Station (Bulletin 100, 1906)

makes it possible to gather together the known facts, so far as

they relate to that State, and derive from them some general con-

clusions.

It is not pretended, of course, that the information given by

Rydberg is complete; and it must doubtless be admitted that

some of the recently described species probably do not deserve

that rank; but allowing for these and other elements of doubt and

difficulty, we may still recognize many broad facts which are not

likely to be overthrown. With regard to the details, each state-

ment may be regarded as a challenge to Colorado botanists, to

refute it if they can, and in this way even error may be made the

cause of progress. The Arctic-Alpine Zone begins at timber line,

or the upper limit of trees. This may be roughly placed at an

altitude of 12,500 feet, but it differs according to the character of

the exposure as well as the latitude, and may actually descend con-

siderably lower. In order to omit nothing, I listed all the plants

given by Rydberg as growing at 12,000 feet or above: 386 species.

Of these, 202 are not recorded as going above 12,500 feet, and

may therefore not pass beyond the Hudsonian Zone; 92 of the

386 descend to below 8000 feet, and of these, 62 do not go above

12,500 feet.

Old World Species

Forty-eight species (probably more!) extend to the Old World,

861

862 THE AMERICAN NATURALIST [Vor. XL

most of them being eircumpolar, but a few only reaching eastern

Asia. I have divided these into four groups :—

(1) Going above 12,500 feet, and not below 11,000 (10

species) : —

Carex incurva Lightf. Papaver radicatum Rottb.

C. atrata L. Saxifraga cernua L.

C. pyrenaica Wahl. Dryas octopetala L.

C. rupestris All. Dasystephana romanzovii (Ledeb.)

C. microglochin Wahl. Sagina nivalis Fries.

(2) Going above 12,500, but also below 11,000 feet (16

species) : —

Filix fragilis (L.). Silene acaulis L.

Trisetum ee (L.). Draba aurea Wahl.

Poa alpina L. Muscaria adscendens (L.).

Elyna bellardi (All.). Leptasea flagellaris (Willd.).

Carex nigricans C. A. Mey. (to Asia). Potentilla nivea L..

Juncoides spicatum (L.). Sibbaldia procumbens L.

Lloydia serotina (L.). `- Campanula ee L.

Oxyria digyna (L.). : Erigeron uniflorus L

(3) Not going above 12,500 or below 11,000 feet (3 species) :—

Botrychium lunaria (L.). Carex misandra R. Br.

Aster alpinus L.

(4) Not going above 12,500, but going below 11,000 feet (19

species) :—

Phleum alpinum L. Thalictrum alpinum L

Festuca pseudovina Hackel. Epilobium anagallidifolium Lam.

Carex nardina Fries. Moneses uniflora (L.).

C. alpina Sw. Pyrola secunda L.

C. capillaris L. P. minor

Lemna gibba L. .. P. ulig nosa Torrey (to Japan).

Juncus castan us Smith. P. chlorantha Schwartz.

Vagnera stellata (L.). Utricularia vulgaris L.

Bistorta vivipara (L.). Adora moschatellina L.

Ranunculus affinis R. Br. (to Asia).

1 In addition, Alsine baicalensis and A. læta are said to occur in Asia.

No. 480] ALPINE FLORA OF COLORADO 863

Muscaria adscendens (L.), according to Nelson, is different

from our plant; in this case the latter must be removed from the

circumpolar list, and will bear the name Muscaria oregonensis

(Ponista oregonensis Raf., 1836).

It will be seen that of the Old World species, 26 go above 12,500

feet, and 13 do not go below 11,000. Seven, however, go below

8000. Admitting that the figures are only rough and approximate,

it still comes out quite clearly that the eircumpolar flora, while of

course boreal, is not especially arctic-alpine. The most character-

istic arctic plant is no doubt the Papaver, which seems curiously

out of place in. our flora.

Out of the 48 the following occur in the British Islands, which are

neither arctic nor greatly elevated :—

Botrychium lunaria (L.). _ Bistorta vivipara (L.).

Fiix fragilis (L. Silene acaulis

Phleum alpinum L Thalictrum alpinum L.

Poa alpina L. Saxifraga cernua L.

Carex incurva Lightf. Dryas octopetala L.

C. alpina Sw. Sibbaldia procumbens L.

C. atrata L. —. Epilobium anagallidijolium Lam.

C. rupestris All Pyrola secunda L.

C. capillaris L. P. minor L.

Lemna gibba L. Utricularia vulgaris L.

Juncus castaneus Smith. Adoxa moschatellina L.

Juncoides spicatum (L.). Sagina nivalis Fries.

Oxyria digyna (L.).

Species Which go above 12,500 Feet, but are Confined to America

(1) Species which extend to British America or Alaska

(a) Species not reported below 11,000 feet (7 species): —

Poa arctica R. Br. Ranunculus eschscholtzii Schl.

Salix petrophila Rydb. Draba fladnizensis

Alsinopsis rossii (Richards). - Castilleja occidentalis Torrey.

A. quadrivalvis (R 7

Castilleja tincta (C. pallida occidentalis tincta Ckll., Bull. Torr.

Bot. Club, 1890, p. 36) is doubtless a hybrid between occidentalis

and haydent.

THE AMERICAN NATURALIST

[Vor. XL

(b) Species going below 11,000 feet (31 species) :—

Deschampsia alpicola Rydb.

Poacrocata Mich. (Goes below 8000.)

Festuca brachyphylla Schultes.

Carex festiva Dewey. (Down t06500.)

C. petasata Dewey.

Juncus drummondii Mey.

Saliz glaucops Anders. (Down to

7000.)

Alsinopsis propinqua (Richards).

A. obtusiloba Rydb.

Androsace carinata Torrey

Anthopogon elegans (A. Nabb):

Phacelia sericea H

Castilleja. rhexifolia Ry db. (Down

to 7000.)

Solidago ciliosa Greene.

Antennaria media Greene.

Draba crassifolia Graham.

Rhodiola integrifolia Raf.

Heuchera parvifolia Nutt.

Muscaria delicatula Small.

Leptasea ee (Wieg.).

(Down

Potentilla SER Rydb.

P. dissecta Pursh.

P. uniflora Ledeb.

P. rubripes Rydb.

Atelophragma elegans

(Down to 7000.)

Linnea americana Forbes.

Arnica parryi A. Gray.

Senecio columbianus Greene. (Down

~ to 5000.)

S. purshianus Nutt.

6000.)

(Hook.).

(Down to

Agoseris aurantiaca (Hook.). (Down

6000.)

Taraxacum scopulorum (Gray).

The two species of Alsinopsis are modifications of well known

eircumpolar types. A. propinqua has been considered identical

with Alsinopsis hirta (Arenaria hirta Wormsk.), which has itself

been placed as a variety of Alsinopsis verna (Arenaria verna L.).

A. obtusiloba, which my wife obtained in abundance on Arapahoe

Peak, Colo., on Sept. 1 of the present year, is a segregate from

Alsinopsis sajanensis (Arenaria sajanensis Willd.). Sedum

stenopetalum Pursh, is given by Rydberg as only up to 12,000;

but my wife found it far above timber line on Arapahoe Peak.

(2) Species which do not extend beyond the United States.

(a) Species not reported below 11,000 feet (35 species) :—

Avena mortoniana Scribn. (Colo. Carex elynoides Holm. (Colo. only.)

Allium pikeanum Rydb. (Colo.

only.)

only.

Poa pudica Rydb. (Colo. only.)

P. alpicola Nas Eriogonum aureum Nutt. (Colo.

P. rupicola Nash. only.

P. gra,ana Vasey. (Colo. and E. zanthum Small. (Colo. only.)

Wyo. only.) Paronychia pulvinata A. Gray.

P. lettermannii Vasey. (Colo. and Cerastium pulchellum Rydb. (Colo.

Wyo. only.) only.)

No. 480]

Ranunculus ocreatus Greene. (Colo.

only.)

SmelowskialincarilobaRydb. (Colo.

only.)

Erysimum nivale (Greene).

Draba chrysantha S. Wats.

and N. M. only.)

D. streptocarpa grayana Rydb.

(Colo. only.)

D. decumbens Rydb. (Colo. only.)

Leptasea chrysantha A. Gray. (Colo.

and N. M.)

Oreoxis humilis Raf.

Phlox condensata (A. Gray).

and N. M.)

Polemonium speciosum Rydb.

Eritrichium argenteum Wight.

Mertensia bakeri Greene. (Colo.

only.)

(Colo.

ALPINE FLORA OF COLORADO

' Antennaria

865

(Colo. only.)

(Colo.

M. alpina (Torrey).

Chionophila jamesii Benth.

and So. Wyo.)

Chrysopsis alpicola Rydb. (Colo.

and Wyo.)

sierre-blance Rydb.

(Colo. only.)

Artemisia scopulorum A. Gra

A. monocephala (A. Gray). (Colo.

only.)

A. saxicola Rydb. (Colo. and

yo.

Senecio soldanella A. Gray. (Colo.

only.)

S. petrocallis Greene. (Colo. only.)

S. porteri Greene. (Colo. only.)

Carduus hesperius (Eastw.). (Colo.

only.)

Of all these, certainly the most remarkable is the Chionophila.

The large number of endemic alpine species is especially note-

worthy.

E. asperum nanum Ckll.,

The earliest name for the dwarf alpine Erysimum is

(Nature Notes , 1891, p. 15).

Above

timber line on the Truchas Peaks of northern New Mexico is

another endemic Mertensia, M. celestina Nels. & Ckll.

: (b) Species going below 11,000 feet (78 species) :—

Poa reflexa V. & S.

P. pattersonii Vasey. (Colo., Ariz.)

P. epilis Seribn.

Agropyron scribneri Vasey.

Carex chalciolepis Holm.

only.

Juncus parryt Engelm

Salix pseudolapponum Seem: (Colo.

only.)

S. saximontana Rydb.

Claytonia megarrhiza Parry.

Alsine baicalensis Coville (to Asia?)

Clementsia rhodantha (A. Gray).

(Colo.

Rhodiola polygama Rydb. (Colo.,

N. M.)

Telesonix jamesii (Torrey). (Colo.

only.)

Sazijraga debilis Engelm.

S. simulata Small.

Spatularia vreelandii Small.

Trijolium nanum Torrey.

T. dasyphyllum Torrey.

7000.)

(Down to

T. parryi A. Gray.

Sidalcea candida A. Gray. (Down

to 7000.)

Epilolium ovatifolium Rydb.

Oreoxis bakeri C. & R. (Colo. only.)

Angelica grayi C. & R. (Colo. and

Primula angustijolia Torrey. (Colo.

and N. M.)

P. parryi A. Gray.

Hudsonian Zone.)

(Properly

866

Swertia palustris A. Nels.

Phlox scleranthifolia Rydb.

P. cespitosa Nutt.

Gilia pinnatifida Nutt. (Down to

Polemonium scopulinum Greene.

(Colo. only.)

P. grayianum Rydb.

P. conjertum A. Gray.

(Colo. only.)

(Wyo.,

Colo.)

Bistorta bistortoides (Pursh.).

(Down to )

Paronychia diffusa A. Nels. (Down

to 5000.)

Arenaria fendleri A. Gray. (Down

to 7000.

A. fendleri porteri Rydb. (Down

to 7000.

Delphinium barbeyi H

D. alpestre Rydb. vim only.)

Anemone zephyra A. Nels.

Thlaspi glaucum A. Nels.

Erysimum radicum Rydb.

only.)

E. amenum (Greene.) (Colo. only.)

Draba parryi Rydb. (Colo., Wyo).

D. streptocarpa A. Gray. (Down to

(Colo.

6000.)

Potentilla minutifolia Rydb. (Colo.

only.)

P. tenerrima Rydb. (Colo. only.)

P. saximontana Rydb. (Colo. only.)

Acomastylis turbinata (Rydb.).

Pentstemon hallii A. Gray. (Colo.

only.

P. harbourii A. Gray. (Colo. only.)

v alpina (A. Gray.)

eine Benth. (Down to

pe grayt A. Nels.

THE AMERICAN NATURALIST

[Vor. XL

P. scopulorum A. Gray. inii only.)

Valeriana acutiloba Ryd

Chrysothamnus nn Greene.

(Down to 7000; is 13,000 perhaps

erroneous?)

' Tonestus pygmeus T. & G.

Solidago decumbens Greene.

and Colo.)

Townsendia rothrockii Gray.

Macheranthera pattersonii (Gray).

(Colo. only.)

Aster andinus

11,000

Erigeron pinnatisectus (Gray).

Antennaria umbrinella Rydb.

re to

viscidula A. Nels.

(Wyo.

Nutt. (? Below

(Wyo. and

Tetraneuris lanata (Nutt.). (Down

Rydbergia grandiflora (T. & G.)

R. brandegei (A. Gray). (Colo. and

N. M.

Senecio amplectens A. Gray. (Colo.

only.)

S. holmii Greene. (Colo. only.)

S. taraxacoides (A. Gray). (Colo.

only.)

S. carthamoides Greene. (Colo. and

Wyo.)

S. crassulus A. Gray.

S. atratus Greene. (Colo. only;

down to 7500.)

S. harbourii Rydb.

S. rosulatus Rydb.

down to 5000

S. jendleri A. Gray.

S. crocatus Rydb. (Wyo. and Colo.)

Agoseris maculata Rydb. (Colo.

. only.)

(Colo. only.)

(Colo. only;

Sidalcea candida is typical of the Canadian Zone; I have never

seen it at timber line or above.

No. 480]

ALPINE FLORA OF COLORADO

867

Species not Reported above 12,500 Feet nor below 11,000

(1) Species which extend to British America or Alaska (3

species) :—

Draba cana Rydb.

Artemisia spithamea Pursh.

Carduus hookerianus (Nutt.).

(2) Species which do not extend beyond the United States (19

species) :—

Deschampsia curtijolia Seribn.

Poa phenicea Rydb. (Colo. only.)

Carex chimaphila Holm.

onl

y-)

C. engelmannii Bailey. (Colo.

only.

Arenaria tweedyi Rydb.

Draba graminea Greene.

only.

Micranthes brachypus Small.

. Trifolium salictorum Greene. (Colo.

only.)

Swertia congesta A. Nels.

Gilia cephaloidea Rydb.

(Colo.

Eritrichium elongatum (Rydb.).

ensia picta Rydb. (Colo.

only.)

M. parryi Rydb. (Colo. only.)

M.canescens Rydb. (Colo. only.)

Castilleja haydeni (A. Gray). (Colo.

and N. M.)

Erigeron melanocephalus A. Nels.

Achillea alpicola Rydb.

Senecio invenustus Greene. (Colo.

only.)

S. lapathijolium Greene. (Colo.

only.)

Thus a restricted vertical range goes with a restricted latitudinal

one as might be expected. Castilleja haydeni is exceedingly

abundant just above timber line on the Sangre de Cristo range.

Species not Reported above 12,500 Feet but going below 11,000

(1) Species not reported below 8000 feet.

(a) Species which extend to British America or Alaska (31

species) :—

Picea engelmanni (Parry).

Abies lasi (Hooker).

Trisetum majus (Vasey).

Poa leptocoma Bong.

Salix chlorophylla Anders.

Polygonum montanum (Small).

Alsine læta (Richards).

‚Cerastium beeringianum C. & 8.

Mehringia macrophylla (Hooker).

Caltha leptosepala Hooker.

Aconitum columbianum Nutt.

Pectianthia pentandra (Hooker).

Micranthes arguta (D. Don).

Potentilla pinnatisecta (S. Wats.).

Erythrocoma ciliata (Purs

Pyrola asarifolia Mx.

868

Vaccinium cespitosum Mx.

V. poreohilum Rydb

V. erythrococcum Rydb.

Chondrophylla americana (Engelm.).

Phacelia ciliosa Rydb.

Mimulus langsdorfii Sims.

Veronica wormskjoldü R. & S.

(Goes above timber line in New

Mexico.) :

THE AMERICAN NATURALIST

[Vor. XL.

Castilleja lancifolia Rydb.

Elephantella grænlandica (Retz.).

Pedicularis racemosa Dougl.

P. bracteata Benth.

Aster apricus (A. Gray).

Erigeron salsuginosus (Rich.).

Hieracium gracile Hooker.

Agoseris gracilens (A. Gray).

(b) Species confined to the United States, or not extending

north of the British Boundary (71 species) :—

Pinus aristata Engelm.

Stipa minor (Vasey).

Poa sheldonii Vasey.

Festuca minutiflora Ryd

F. thurberi Vasey.

Carex melanocephala Tur

C. scopulorum Holm.

Anticlea coloradensis R

Polygonum commixtum ^ ap

Oreobroma pygmaa (A. Gray).

earlei Rydb. (Colo.

ur only.)

(Colo. only.)

y-)

C. vicies le Gre

Trollius albiflorus KA Gray).

Aquilegia saximontana Rydb. (Colo.

only.)

Aconitum bakeri Greene

Ranunculus arte Greene.

(Colo. only.)

R. alismejolius Geyer.

R. macauleyi A. Gray. Ph only.)

R. alpeophilus A. Nels

R. adoneus A. Gray.

Thlaspi nuttallii Rydb.

Smelowskia americana Rydb.

Pentstemon glaucus Graham.

Castilleja lauta A. Nels.

C. linearis Rydb. (Colo. only.)

C. puberula Rydb. (Colo. only.)

Pedicularis parryi A. Gray.

Campanula parryi A. Gray.

Macronema discoideum Nutt.

ster fremontii A. Gray.

Draba crassa Rydb.

D. spectabilis Greene.

D. luteola Greene. (Colo. only.)

Micranthes arnoglossa (Greene).

Ribes lentum (Jones).

Lupinus parviflorus Nutt.

Trijolium brandegei S. Wats. (Colo..

only.)

T. stenolobum Rydb. (Colo. only.):

T. lividum Rydb.!

Geranium pattersonii Rydb. (Colo.

nly.)

Viola bellidifolia Greene.

Oreoxis alpina (A. Gray).

Ligusticum porteri C. & R.

Pseudocymopterus montanus (A.

Gray).

P. sylvaticus A. Nels.

Androsace subumbellata (A. Nels.).

Anthopogon barbellatus (Engelm.).

(Colo. only.)

Amarella monantha (A. Nels.).

(Colo. only.)

A. scopulorum Greene.

A. plebeja holmii (Wettst.).

1 Trifolium lividum is given by Rydberg as extending to 12,000 feet; my

wife found it on Arapahoe Peak about timber line.

No. 480] ALPINE FLORA OF COLORADO 869

Dasystephana parryi (Engelm.).! Arnica silvatica Greene.

Phlox kelseyi Britton. A. rydbergii Greene.

Polemonium delicatum Rydb. (Colo., A. tenuis Rydb.

N. M.) A. subplumosa Greene.

Mertensia polyphylla Greene. Senecio pagosanus Heller. (Colo.

Erigeron leucotrichus Rydb. only.)

E. leiomerus A. Gray. S. blitoides Greene. (Colo. only.)

E. elatior A. Gray. S. pentodontus Greene.

E. coulteri Porter. Carduus scopulorum Greene. (Colo.

E. salsuginosus glacialis (Nutt.). only.

E. viscidus Rydb. (Colo. only.) C. griseus Rydb. (Colo. only.)

Antennaria nardina Greene. Agoseris pumila (Nutt.).

To these may be added the two following:—

Mertensia perplexa Rydb. Arapahoe Peak, Colo., in a draw just.

above timber line (W. P. Cockerell).

Senecio triangularis Hooker. Arapahoe Peak, at timber line (Dr. F.

Daniels and W. P. Cockerell).

(2) Species going below 8000 feet. In the case of some of

these, the range to 12,000 feet may need confirmation. It is not

impossible that misunderstandings have sometimes arisen, as the

result of vague labeling.

(a) Species extending to British America or Alaska (24

species) :—

Equisetum levigatum A. Br. Ribes parvulum (A. Gray).

Calamagrostis purpurascens R. Br. Lepargyrea canadensis (L.).

(To Greenland.) Osmorrhiza obtusa (C. & R.).

Festuca ingrata (Hack.). (Washingtonia obtusa ba = >

Agropyron violaceum (Hornem.). Androsace puberulenta R

(To Greenland.) Amarella strictiflora ka

Carex ebenea Rydb. Dasystephana affinis (Griseb.).

Anticlea elegans (Pursh). Veronica americana Schwein.

Eriogonum flavum Nutt. Campanula petiolata D. C.

Anemone globosa Nutt. Erigeron multiflorus Rydb.

Ranunculus ellipticus Greene. E. glabellus N utt.

Thalictrum venulosum Trelease. Antennaria aprica Greene.

Sedum stenopetalum Pursh. (But Achillea lanulosa Nutt.

really goes higher than EIER Lygodesmia juncea (Pursh).

reports.)

1 Mixed with this according to Greene, is a second species, Dasystephana

bracteosa (Gentiana bracteosa Greene, Pitt., vol. 4, 180.)

870

THE AMERICAN NATURALIST

[Vor. XL

The Campanula and Achillea are offshoots from Old World

types, and were until recently considered identical with them.

(b) Species not going north of the British Boundary (32

species) :—

Blepharineuron tricholepis (Torrey).

(To Mexico

Poa longipedunculata Seribn.

P. pratericola Rydb. & Nash.

P. buckleyana Nash.

Eriogonum umbellatum Torrey.

Cerastium pilosum Greene. (Colo.

only.)

C. oreophilum Greene.

fornia.)

Arenaria confusa Rydb.

Silene hallii S. Wats.

Aquilegia cerulea James.

Erysimum wheeleri S. Wats.

Heuchera hallii A. Gray.

(To Cali-

(Colo.

only.)

Micranthes rhombifolia (Greene).

Ribes wolfit Rothr

allis Ps (Nutt.).

Viola nadensis neomexicana

(Greene).

Gayophytum racemosum T. & Q.

Polemonium brandegei (A. Gray).

(Colo. only.)

Phacelia alpina Rydb.

Mertensia pratensis Heller.

M. viridula Rydb. (Colo. only.)

Besseya ritteriana (Eastw.). (Colo.

onl

Sambucus microbotrys Rydb.

Chrysopsis arida A. Nels.

Oreochrysum parryi A. Gray.

rigeron glandulosus Porter.

E. superbus Greene. (Colo. only.)

Dugaldia hoopesii (A. Gray).

Arnica monocephala Rydb.

Senecio pudicus Greene. (Colo. only.)

Carduus oreophilus Rydb. (Colo.

only. j

Agoseris agrestis Osterh. (Colo.

only.)

Taking the whole list of species which reach 12,000 feet, arranged

in systematic order, we note many points of interest.

(1) There is only one fern, a circumpolar species.

(2) ‘The grasses number 33, of which four are cireumpolar, but

others are very close to Old-World types.

There is an appreciable

element of endemic alpine grasses.

(3) The Cyperacee number 20, of which 11 reach the Old

World. All but one (Elyna) belong to Carex.

(4) Of the four Juncacee, two are circumpolar.

For a

very interesting account of the allies of Juncoides spicatum in

Africa, see Engler in Ann. Bot., Oct., 1904.

(5) In Portulacaces, the peculiar alpine Claytonia megarrhiza

is noteworthy. It belongs to a distinct subgenus which ranges

from Asia into our Rocky Mountains.

(6) The Alsinacez are numerous (18 species); one (Sagina

No. 480] ALPINE FLORA OF COLORADO 871

nivalis) is circumpolar. Alsine baiealensis appears to have a

singular distribution; north to Montana and Oregon only, and -

then reappearing in Central Asia. It may be that the identity

of the Asiatic and American plants needs confirmation. Alsine

leta is supposed to reach Siberia, though Rydberg says nothing

of its ranging beyond our continent.

(7) The Ranunculacez are well represented (21 species),

but are mostly of the Hudsonian Zone rather than the Arctic-

Alpine; 16 do not range above 12,000 feet.

(S) The Cruciferee are represented by Thlaspi (4), Smelow-

skia (2), Erysimum (4), and Draba (13). Only Draba aurea

appears to be circumpolar.

(9) The Rosacez include as many as 9 species of Potentilla.

Of the 14 species of this family, only 3 fail to go above 12,500 feet.

(10) The Leguminosz include no circumpolar types, and only

one reaches British America; 7 out of the 9 belong to Trifolium.

(11) The Epilobiacez number only 3; Chamenerion angusti-

folium (L.) should probably be added, as my wife found a reduced

form of it above timber line on the Truchas Peaks in New Mexico.

(12) Of the 8 Umbelliferee none is circumpolar, and only one

appears to reach British America.

(13) Of the 6 Pyrolacex, four are cireumpolar, and a fifth

reaches Japan. The species of Pyrola exhibit a remarkable

degree of stability.

(14) No Ericacex, in the restricted sense, are in the list, but

I believe Kalmia microphylla (Hooker) should be there.

(15) The Gentianaceze number 12; while only one is supposed

to extend to the Old World, others are very close to Asiatic and

European species. Anthopogon elegans was formerly not separated

from Anthopogon dentosus (Gentiana dentosa Rottb.). Amarella

monantha was considered by Gray inseparable from Amarella

tenella (Gentiana tenella Rottb.). Amarella strictiflora was con-

sidered a form of Amarella amarella (Gentiana amarella L.).

Chondrophylla fremontii was referred to Chondrophylla humilis

(Gentiana humilis Stev.). Dasystephana romanzovii was not

separated from Dasystephana frigida (Gentiana frigida Haenke).

The species of Swertia were included in S. perennis L.

(16) The Polemoniacee consist of four species of Phlox,

872 THE AMERICAN NATURALIST [Vor. XL

two of Gilia, and six of Polemonium. Not one reaches the Old

World, or even, apparently, British America.

(17) The Boraginacez include two species of Eritrichium and

ten of Mertensia; all peculiar to the western United States but

closely allied to arctic species.

(18) Of the 23 Scrophulariacez, nine reach British America

(two even Greenland), but none is eircumpolar. Veronica worm-

skjoldii, however, is a slightly modified form of the type repre-

sented in Europe by V. alpina L. Veronica serpyllifolia L., a

truly circumpolar species, occurs in Colorado only up to 11,000

feet, according to Rydberg. I found it on the top of the Las

Vegas Range in New Mexico, at 11,000 feet, June 28, 1902. The

plants were, however, divergent from typical serpyllifolia, repre-

senting a new variety or subspecies neomexicana, about 15 cm.

high, puberulent, flowers deep blue, calyx lobes oblong, obtuse.

(19) Linnea americana and Campanula petiolata are only

slightly modified representatives of Old-World types.

(20) ‘The Composite are very numerous, 79 species. The two

largest genera are Erigeron (14 species) and Senecio (24 species).

Carduus has 5, Arnica 6, Artemisia 4, Antennaria 6, Aster 4,

Solidago 2. These are circumpolar genera; but there are some

endemic genera, partly of austral derivation, the most remark

able of which is Rydbergia.

(21) The following families, represented in the Colorado flora,

are wholly absent from our list of species reaching 12,000 feet.

Marsileacex (7720). Elodiacex (6500).

Isoétacee (8150). Araceæ (4500).

Lycopodiacee (10,500). Commelinacex (6500).

Juniperacex (10,000). Pontederiacez (5500).

Ephedracex (7000). Dracænaceæ (8000) .'

Typhacez (6000). Calochortaces (10,000).

Sparganiacez (11,500). Trilliaceze (9000).

Zanichelliacez (11,500). Smilacaces (6000).

Naiadaces (5100). Ixiacez (10,000).

Scheuchzeriaces (10,000). Orchidacex (11,500).

Alismaceze (9000). Monotropacex (8000).

* Rydberg gives Yucca glauca as only reaching 6000 feet; this is erroneous,

as it reaches 8000 at Florissant and elsewhere. Rydberg’s maximun for the

family is 6500.

No. 480]

Ericacez (11,000).

Oleacez (5000).

Menyanthacez (8000).

Heliotropaceze (4800).

Verbenacex» (7500).

Labiatz (Lamiacez) (10,000).

Solanacez (10,000).

Betulacez (11,000).

Corylacez (8000).

Fagacex (11,000).'

Urticacex (9000).

Cannabinacex (8000).

Ulmacez (6000).

Loranthaces (8850).

Santalacez (8000).

Chenopodiacez (10,000).

Amaranthacez (10,000).

Allioniacez (9000).

Tetragoniacez (8000).

Ceratophyllacex (Platte Riven:

Nympheeaceze (11,000

Berberidacee (10,000).

Fumariacee (10,000).

Capparidacez (9000).

Parnassiacez (11,000).

Hydrangeacee (10,000).

Malacez (11,000).

Amygdalacex (9500).

Mimosacez (3920).

Cassiacez (7000).

Apocynace (9500).

Asclepiadacez (9000).

ALPINE FLORA OF COLORADO 873

Cuscutacez (7000).

Convolvulacez (7000).

Orobanchacez (11,000).

Martyniacez (5340).

Plantaginacex (10,000).

Linacez (10,000).

Oxalidacesz (9000).

Zygophyllacez (5340).

Rutacez (5400).

Polygalacex (5000).

Euphorbiacez (8000).

Callitrichaceze (5340).

Limnanthacez (6500).

Spondiacez (8000).

Celastracez (10,000).

Aceracex (9000).

Elatinacee (Platte River).

Frankeniacee (5340).

Hypericacez (10,000).

Cistaceze (Douglas County).

Loasacez (10,000).

Cactacez (11,000).

Lythracez (6000).

Gunneracez (10,000).

Hederace:x (9000).

Cornacez (10,000). .

Rubiacez (10,000).

Cueurbitacez (5100).

Lobeliacex (5200).

Ambrosiacez (8000).

The numbers following the family names indicate the highest

altitude in feet to which the families ascend in Colorado accord-

ing to the data given by Rydberg.

! Quercus nitescens Rydb., 11,000. This is very high for an oak. Although

oaks are so abundant at Manitou, we found none at Florissant, 8000 feet.

They go higher, however, in the Sangre de Cristo range.

BLOOD GILLS OF SIMULIUM PICTIPES

THOMAS J. HEADLEE

Ir is a well known fact that during larval life many aquatic in-

sects possess gills. ‘These have been regarded as thin transpar-

ent extensions of the body wall, which may or may not contain

trachee. In one type of insect gill, the organ is abundantly sup-

plied with trachez, and the evident function of the organ is the

purification of the air contained in the trachex. Such a gill is

known as a tracheal gill. In the other type, known as a blood

gill, it is blood within the gill that is purified.

Whether there exist in pterygote insects true blood gills in the

narrow application of this definition, is still an open question.

Such organs have been described as present in many groups, not-

ably in the larvæ of Trichoptera and Diptera. ‘Those interested

in the general discussion of the subject may find a concise but

excellent résumé of the work done in Kolbe (93) and Packard (’98).

Few of these so called blood gills have, however, been subjected

to morphological examination. It is the purpose of the present

paper to discuss from this view-point these structures of the larva

of Simulium pictipes Hagen, a species of black-fly abundant in

the streams about Ithaca, New York, but I shall first consider

some of their grosser variations which appear in other species of

Simulium.

Projecting from the anus on the dorsal side of the last abdomi-

nal segment, there may be seen in the living black-fly larva, three

white, soft, curved filaments, which are in some species simple and

in others branched. As long ago as 1823, Verdat called attention

to these structures and gave good figures of the lateral and dorsal

views of the larva of Simulium serieium Fries, showing three un-

branched gills arising from the dorsal side of the posterior end of

the body. His figures have been copied by a number of writers.

Graber (’77) figured the unbranched gills of the larval Simulium

columbaczense Schönb. C. V. Riley (’87) figured two types —

875

876 THE AMERICAN NATURALIST [Vor. XL

the unbranched filaments of Simulium meridionale Riley, and the

branched structures of Simulium pecuarum Riley. Curiously

enough, although figuring the gills in their correct position, Riley

states in his general discussion that they occur on the under side

of the body — a statement made by Osten Sacken sixteen years

earlier, although even he contradicted himself by copying the fig-

ures of Verdat. In addition to these there have been figured, by

Meinert (’86), who refers to them as anal papillze, the unbranched

gills of Simulium ornatum Meigen, by ‘Townsend (93) the branched

type of a species of Simulium from the Grand Cañon of Colorado,

by Lugger (796) the simple type of Simulium trıbulatum Lugger,

and by Johannsen (:03) the unbranched type of Simulium hirti-

pes Fries.

Miall and Hammond seem to have been the first to call attention

to the fact that these structures are retractile into the rectum, a

fact which may be verified by study of living, or better, sectioned,

specimens.

Most writers agree that these filaments are gills but there is a

divergence of opinion regarding the method by which they func-

tion. Planchon (44), Osten Sacken (’70), Riley, Townsend, and

Comstock (795) considered them as tracheal gills, Osten Sacken,

Riley, and Osborn even stating that they connect with large inter-

nal tracheæ. Miall and Hammond, and Johannsen, on the other

hand, regarded them as blood gills and without trachez. Such is

the condition of our knowledge concerning this mode of respira-

tion of Simulium larvee. No connected work on the finer anatomy

of their gills has been published. Such mention of the subject as

occurs is confined to the gross anatomy and is scattered through

accounts of life histories and descriptions of species.

In.undertaking a more detailed study of the subject as exempli-

fied in Simulium pietipes, both living and sectioned larve have

been examined. For the study of the trachez found in the region

of the gills it is very helpful to examine living larvee, as in fixed

material the lack of air in these passages makes it hard to see their

finer branches. Most of the histological details were, of course,

gained through a study of sections. To prepare these, larvæ were

killed and fixed in Flemming's mixture, in hot and cold absolute

alcohol, and in hot and cold Gilson's fluid. The hot alcohol and

No. 480] BLOOD GILLS OF SIMULIUM 877

hot Gilson’s fluid were about equally successful. The material

killed in the former cut easily but showed some shrinkage, while

that prepared with the latter cut less easily and showed less shrink-

age. ‘The Flemming material cut so poorly that the preparations

made from it were of little value. By staining on the slide with

Gage’s hematoxylin and orange G, the tissues were well differ-

entiated.

In the living larva the gills are white, soft, and translucent, and

Fig. 1.— A. Dorsal view of the eis of Simulium inii (X8 B. Dorsal

the S projecting from the

view of the posterior end of the larva showin

anus, ( 13). C. Projected hm showing the main filam , finger-like

branches, and some of the nuclei in each, (X 57). a, anus re slightly oo

jecting gills; b, strongly ed nized X-sha piece; c, dorsal wall of t

aped

rectum which has been ev iras and covers the bases of ie gills; d, mueio er

main and branch filament

appear on the dorsal side of the last abdominal segment, just ante-

rior to a dark, strongly chitinized, X-shaped piece (Fig. 1, A, a, b).

"They are projections of the ventral wall of the rectum and lie,

when retracted, completely within the rectal cavity (Fig. 2, A).

878 THE AMERICAN NATURALIST [Vor. XL.

They consist of three main filaments arising from the ventral rec-

tal wall, each about 400 » long and 120 wide at the base, tapering

to 75 near the middle and to 60 at the distal end, and each fur-

nished with many finger-like branches arising from their lateral

and ventral walls (see Fig. 1, B.).

As might be expected from their morphological relationship,

Fic, 2.— A. Sagittal section of the posterior end of the larva showing the gill

within the rectum and showing the Simi po Red yd componen t layers to tho:

of the rectum, (X 52). B. Similar owing the gill projecting,

(x 52). C. Similar raum showing dé rem ar tel to its fullest extent.

(X 53). a, cuticle of body wall; a’, intima of rectum and gill; b, hypoder-

mis; b’, rectal epithe iM b^, gill epithelium; 6”, normal hind-intestinal

epithelium; c, basement membrane; d, and d', transition from body wall to

Aum layers on the dorsal and ventral sides respectively ; e and e’, transition

from rectal to normal D layers on the dorsal and ventral sides

respectively f, body g, main filament; Ah, cavity of main filament;

finger-like branch; j, gre of branch.

the gills are composed of the same three layers as is the rectum;

the intima on the surface, the epithelium next, and the basement

membrane adhering closely to the epithelium and lining the gill

cavity. ‘The intima is exceedingly thin, perfectly transparent and

No. 480] BLOOD GILLS OF SIMULIUM 879

without apparent structure. The epithelium is a layer varying

in thickness from 5 x to 18 x, composed of large, distinct, somewhat

flattened cells well filled with cytoplasm, and containing each a

single large nucleus, in which the nucleolus and chromatin mark-

ings are very distinct. The chromatin occurs throughout the

nucleus but is distributed a little more thickly around the peri-

phery (Fig. 3, A and C). The basement membrane is very thin

and much like that found under the hypodermis (Fig. 2, A).

At the point of union be-

tween the body wall and the

rectum there is a marked de-

crease in the thickness of the

layers, the intima and epitheli-

um being’ much more delicate

than the cuticle and hypoder-

mis; and this condition is

continued to a point some

distance cephalad of the gill

(Fig. 2, A) except that the

epithelium of the gills is thick-

er than that of the chamber

containing them. The base-

ment membrane continues

x and distal end, (X 255). B. Similar sec-

from the hypodermis through tion taken near distal end, (X 255). C

the gill with out noticeable Cross section of a finger-like branch taken

in the region of the nucleus, (X 255).

change.

'The cells lining the distal lium; c, cavities of both branch and main

i U it

and base, (X 255). a, intima; b, epithe-

end of the main filament are ments; d, nucleus; e, nucleolus; f.

chromatin granule; g, base of a finger-like

slightly larger than those at branch

the base (Fig. 3,A,B). Each

finger-like branch is composed of a single large cell, the base of

which helps to form the wall of the main filament (Figs. 2, A, and

3,A). These branch cells are much larger than the main filament

cells and contain larger nuclei, in which the chromatin particles

more distinctly appear (Fig. 3, A, B, C). The nuclei are gen-

erally located near the middle in the cells of both the branches and

the main filaments, but in the branches they are often nearer one

side than the other. The nucleus, covered by a thin layer of

880 THE AMERICAN NATURALIST [Vor. XL

cytoplasm, occasionally projects into the cavity which penetrates

the branch. ‘The gill cavities occupy the main filaments, pene-

trate the branches, and communicate freely with the body cavity

at the base of the gills. Found within these chambers are masses

of slender trachex and as their presence in these organs strongly

suggests that they do not function wholly as blood gills, I shall dis-

cuss them in detail.

During the larger part of the time I spent in this work, I believed

trachez to be wanting in these gills, but masses of fine tube-like

structures which appeared in the sections excited doubt. Having

secured some living larve, I cut off, after many unsuccessful

attempts, a projected gill. This being quickly mounted and exam-

ined with a #-inch objective and 1-inch ocular, there appeared

reaching up into the gill cavities, masses of fine tracheal tubes

filled with air. While they enter all parts of the basal opening,

they are thickest in four main bands, two entering the central lobe

and one each of the lateral lobes. This collection into bands

might result from mechanical causes but, as a similar arrangement

appeared in the sectioned material, it seems probable that it is the

natural condition. The tubes are small, about 1: in diameter, of

uniform size, and rarely branching unless in contact with the wall.

They penetrate all parts of the gill cavity, and generally one and

frequently two slender trachez lying close to the wall penetrate to

the very tip of a unicellular branch. When viewed with a oil-

immersion lens there may be seen in mounted and stained sections,

given off from these tracheze which lie close to the wall, fine branches

penetrating the protoplasm. ‘These air vessels gradually decrease

in size as they approach the ends of the cavities. Just below the

base of the gills they average 2 in diameter, half way up the main

lobe they are about 1 x, and near the ends of the finger-like branches

they have decreased to a diameter of 0.84. These measurements

were taken while the tubes were filled with air.

The trachez branch very rarely in the gill cavity and in such

cases as I have observed, the resulting branches were each about

as large as their common parent. I have seen no tracheal trunks

in the gill cavities, although they appear below in the body cavity

and in many cases the slender trachez penetrating the gills have

been traced to them.

No. 480] BLOOD GILLS OF SIMULIUM SSI

While it has not been possible to see the actual blood movement

in the projected gills, the abundance of blood-mass which appears

in the sections in all parts of their cavities clearly demonstrates its

presence there.

The gills may be projected or retracted at the will of the animal.

When out, the middle filament projects dorso-cephalad, the side

filaments dorso-latero-cephalad, and all the branches are thrown

free into the swiftly flowing water which is the normal habitat of

the animal (Fig. 1, B). The projection of the gills includes not

only a movement of the organs themselves but also of the rectum.

The usual amount of movement is shown in Fig. 2, A and B.

Points e and e’ represent the beginning of the normal intestinal

epithelium on the dorsal and ventral sides respectively, while d and

d' represent the beginning of the body wall on the same respective

sides. In Fig. 2, A, the gills are retracted, while in Fig. 2, B, they

are projected as much as the healthy animal usually protrudes

them. In Fig. 2, B, e and &' have moved to the dorsal surface of

the body, while d and d’ have retained almost the same position.

Sometimes, however, the living animal may project the gills to the

extent illustrated in Fig. 2, C, and when killed in hot alcohol gen-

erally does so. This protrusion differs from that of the ventral

sacs in the Thysanura, where the sac is simply turned wrong side

out, for these are projected without being everted.

These gills are almost if not completely withdrawn when the

animal is moving, and project freely only when it is fastened by its

caudal sucker. ‘They are rarely quiet when projecting but are

usually moving a little way in or out.

I have found no muscular apparatus by the action of which the

gills could be projected, but have been able to make them protrude

by pressure exerted progressively from in front backward, and, as

I have found the blood-mass in sections of protruded gills, it seems

only reasonable to conclude that the gills are pushed out by an

inflow of blood under such vn. as might be exerted by a con-

traction of the body muscles.

The gills are retracted by striated muscles which do not, so far

as I can determine, penetrate their cavities. At least eight muscle

bands are inserted on or near the bases of the gills, and each plays

some part in the retraction of those organs. ‘To aid my descrip-

882 THE AMERICAN NATURALIST [Vor. XL

tion of these muscles, I have made a diagram (Fig. 4) to show

their position in the body of the animal, and have designated

those of the left side in the order of their insertion passing from

left to right, by the letters a, b, c, and d, and the corresponding

ones of the right side, also in the order of their insertion passing

from right to left, by the letters a’, b^, c^, and d'. Muscle a, which

has a diameter of about 35 » just before branching, is as large as

any of the gill retractors. It is fastened to the basal region of the

left gill by three branches. One is inserted in the lateral, another

in the dorso-lateral, and a third in the ventro-lateral aspect of the

Fic. 4.— Diagram of the muscles which retract the gills. The dorsal wall of the

tum is cut away along lines 7 and 7’. e ventral wall of the body is exposed

by the first and the floor of the rectum upon " which the gills lie by the second

operation. 1, 2, and 3, the left, central, and right gills; e, strongly chitinized

X-shaped piece; f, anal opening; g, infolding d ds body wall lying on the

abdominal floor just cephalad of the caudal sucker

left gill base. Of these, the second is both the largest and most

clearly inserted. These branches pass cephalad and quickly

fuse to form a, which passes dorso-cephalad and slightly laterad

until it finally fastens to the ventral aspect of the dorsal wall of

the abdomen. After the junction of the three branches forming

a and before it reaches its point of origin, it is joined by muscle b

and later by a large muscle band from the anal region. Muscle

b, which is also a large conspicuous band of about 27 » diameter,

is inserted in the ventral aspect of the tissue between the left and

No. 480] BLOOD GILLS OF SIMULIUM 883

central gill bases. From thence it passes dorso-cephalad and

laterad until it joins muscle a. Muscle c, a smaller, yet plainly

marked band of about 12 » diameter, is inserted in the gill at the

same point as b, and extends ventro-caudad and slightly laterad

“until it reaches the floor of the abdomen where it attaches to an

infolding of the body wall. This infolding extends transversely

across the abdominal floor just cephalad of the caudal sucker.

Muscle d, the diameter of which is slightly less than that of e, is

inserted just mesad of c and extends ventro-caudad and mesad

until it fuses with muscle c' of the right side.

As the muscles of the right side correspond to those of the left

they require no separate discussion.

When the gills are pushed out, the muscles are drawn with the

base into the everted part of the rectum, and when they contract

the gills are pulled back to their place inside.

The presence of functional trachez in their cavities points to the

conclusion that these organs must, in some degree, function as

tracheal gills; for, if they act only as blood gills, the epithelial cells,

inasmuch as the oxygen before reaching the blood must pass

through their substance, would need no tracheation. But the

comparatively small number and size of the trachez supplied to

the gills, together with the undoubted presence of blood in their

cavities, render untenable the hypothesis that they function wholly

as tracheal gills.

In the light of this work it is evident that, except in a remote

morphological sense, not all gills are extensions of the body wall

but that some are borne by the rectum, and it is also evident that

not all insect gills act wholly either as tracheal or as blood gills, but

that some function as both.

In conclusion, I wish to acknowledge my indebtedness to Pro-

fessor J. H. Comstock in whose laboratory this research was

prosecuted, and to Dr. William A. Riley whose constant and kindly

criticism has been invaluable.

884 THE AMERICAN NATURALIST [Vor. XL.

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(No. 479 was issued November 26, 1906)

THE JOURNAL OF EXPERIMERTAL Z00L06Y

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: WILLIAM K. Boo HERBERT S. Sessa Tuomas H. MORGAN

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Epwin G. Conk JACQUE preme CHARLES O. WHITMAN’

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Volume I, Ge 616 pages, 5 plates, and 478 text illustrations, and Volume

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CONTENTS 9 besser,

No. 1— ARY,

Studies on Chromosomes, III. The Sexual fasten renees of the Chromosome-

Groups in Hemiptera, with Some Considerations of the Determination of

x. E B. Wilson

An Examination ot the Effects of Mechavieal Shocks and Vibrations Upon the

Rat Development of Fertilized Eggs . David D. Whitney

Morphology of the ee Development o. of PUER John W. Scott

The Development of Fundulus ee in Solutions of Lithium Chlorid,

with Appendix on its Development in Fresh Water. Charles R. Stockard

ial Regeneration of the un ehe in Crayfish. E. A. Andrews

Experimental ES of Light as a Factor in the Regeneration of Hydroids.

A. J. Goldfarb

No o. 2— Jury, 1906

Experiments on the Behavior of ees Au cree ER C. W. Hargitt

Inheritance of Dichromatism in Lina and Gastroidea Isa bel Mecracken

The Elementary Phenomena of Embryonic Derdini in Chætopter

s ank * Lillie

The Riesonchition “of Grafted Pieces in Plaustians ee UN . Lilian V. Morgan

No, 3— SEPTEMBER, 1906

Locomotion of a and Allied Forms Oris P. Dellin

The ge of Light and Heat on the Movement of the Fe BE

ent, especialy in Liza = - George H. Parke =

Light à Reactions in r Orga 2 “Stentor Coeruleus. 5. 0. M

Some Reactions of eng and Moth

: Alfred G. Mayer and Caroline G. Soule

Modifiability in Behavior. II. Factors Determining Direction and Character

f Movement in the Earthw . S. Jennings

A Stüdy of the Spermatogenesis ot folk tocycta Aurichslcen and Coptocycla. Gut-

tata, with € Reference to the Problem of Sex Determination.

. N. Nowlin

No. 4—Iı

The d of Gases and Temperature on the Cardiac and Bun cipes Move-

of the a. . A. Wallin

The Physiolosy x Reg =

Sagen and > t Transitional Phenomena in ‘the Regeneration of the Cheliped

ster (Homarus Am us). Victor E. Emmel

Studies on the Development of the Starfish Egg.

. H. Tennent ue M. J. Hogue

Hydianth Formation. sud Polarity in Pubgleris; . H. Morgan

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