OFFICERS FOR 1902-1903

Vice-Presidents: Wriuam H. Seaman.. Washington, D. C,

A. M. Hotmes . Denver, Col.

EY IR WAND, 05 occ ccccsdesarsseuasdpececccsess Lincoln, Neb.

Assistant Secretary: R. H. Wowcorr Lincoln, Neb.

Treasurer: J. C. Surrn...... New Orleans, La.

ROMS PULAUIC. ««.0 0 ccccvesdaerswaebass cavectes Pittsburg, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE

SS iin vide age «svcd cecccscde eebbebdauuededat Rochester, N. Y.

ERs Wow civ dhe ccd ced vescddegadudecabudisiiacds Missoula, Mont.

is ld ota nna. cdus senekbtucdeenubebes New Haven, Conn.

EX-OFFICIO MEMBERS OF EXECUTIVE COMMITTEE

Past Presidents still retaining membership in the Society

RH, War, MD, FRMS, of Troy, N. Y,

“ H. L. Surrn, LLD., of Gana et

‘Ausmer McCauts, Ph.D., of Fairfield, Ia,

afore at and, Rates 1 Y., 1879.

at Detroit, Mich. 1880, and at Cleveland, O., 1885.

J. D. Hyarr, of New York City,

at Columbus, O., 1881.

at Chicago, Ill, 1883.

T. J. Buran, Ph.D., of Champaign, IIL,

at Chautauqua, N. Y., 1886.

Geo. E. Feu, M.D., F.R.M.S., of Buffalo, N. Y.,

at Detroit, Mich., 1890.

Frank L. James, Ph.D., M.D., of St. Louis, Mo.,

at Washington, D. C., 1891.

Maxsmaut D. Ewntr, M_D., of Chicago, Ill,

at Rochester, N. Y., 1892.

Simow Hewny Gace, B.S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895.

A. Ciirromp Meacer, M.D., F.R.M.LS., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896.

W. C. Krauss, M.D., of Buffalo, N. Y.,

at Columbus, O., 1899.

A. M. Biers, M.D., of Columbus, O.,

at New York City, 1900.

C. H. Excermann, Ph.D., of Bloomington Ind.,

at Denver, Col., 1901.

at Pittsburg, Pa., 1902.

The Society does not hold itself responsible for the opinions expressed by

members in its published Proceedings unless endorsed by a special vote.

Cuastzs E. Bessry, LL.D., of Lincoln, Neb.,

TABLE OF CONTENTS

FOR VOLUME XXIV

The Annual Address of the President, Evolution in Microscopic Plants,

by Charles B. Boney .:. ic cicvccessuesdcas bostvuveeseanen oskesben

Two Growths of Chlamydomonas in Connecticut, by Frederick S. Hollis,

A Method of Concentrating aamesnibrencsiuncheles::

Seawell . ea PrTTTyiy ete ovbedbune

Prevention of the Pedetic or Brownies. Movement in Milk or other

Liquids with Minute Objects in Suspension, by Simon Henry Gage.. 21

Stereoscopic Photomicrography with High Powers, by F. E. Ives, with

Plate I.. cocccscceehnen

The Structere pers Classification of the ‘Pivciaweees: with a Revision

of the Families and a Rearrangement of the North American

Genera, by Charles E. Bessey, with Plate II.. ccccde chee pa ht ee

The Early Morphogenesis and Histogenesis of the Liver ‘tn Sus scrofa

domesticus, including Notes on the Morphogenesis of the Ventral

Pancreas, by D. C. Hilton, with Plates HI to VI..........-.e+++-. 55

Cultural Studies of a Nematode associated with Plant Decay, by Haven

3 Gu

Metcalf, with Plate VII.. : oonpcenen ee

Data for the Determination of pepe Sabiiiides: by ascy B. Ward, with

Plates VIII-XI.. o oes anata

The North American Species of f Limnesa, by F Robert H. Woleot, with

Plates XII and XIII.. os eeniuie cosvcccoscccguneuee Mam

Necrology, C. M. Vorce, with Plate........... beatipe didi oo sppeousau seen

Minutes of the Annual Meeting. .........0.cceecsecseccecsees 00 ss come een

Minutes of the Mid-Winter Meeting pas go ccepepwnenal 6 aiaiaa

Trensurer’e Repott < o.06.. cickbakcscsepanites 5400p as ncntas rane ica eae

Custodian’s Report, Spencer-Tolles Fund Merritt”

Constitution |. oo. ccscacvescbvcsccetncdvenccatusy aun vecekbennnnee convent

WPTGWS cite codcccdvatecns vicckdes eeuntie 09 040% saeaee

List of Motors, o<.o's'vsins wc cactscdbauususeebmaenateaeeunen occ cnapeages te

Lint Of Sebecreei ends nc'cn cos can cueiersaueeee osecn'egunesankusee oan enon

Biennial Index for Volumes XXIII, XXIV...............- cccccccceson Mae

TRANSACTIONS

The American Microscopical Society

|‘ TWENTY-FIFTH ANNUAL MEETING, HELD AT PITTSBURG, PENN-

SYLVANIA, JUNE 27 AND 28, 1902

THE ANNUAL ADDRESS OF THE PRESIDENT

EVOLUTION IN MICROSCOPIC PLANTS*

By CHARLES EDWIN BESSEY

Although there are many students of the lower forms of plants

and although many microscopists give much time to the examina-

tion of the simpler algae and fungi, they are too generally studied

as mere forms, little or no attention being given to their relation-

ship to one another, or to questions as to their origin and develop-

ment. We have heated discussions as to little details of structure,—

as in the case of the markings on the diatom wall,—while we have

nothing in regard to the meaning and origin of these markings and

other details. Perhaps this is a result of the excessive appreciation

of facts which modern laboratory science has given us. We have

come to such a pass that often the only things we appreciate in an

investigation are the structural facts brought out, while we over-

look as unworthy of our serious attention the deeper meaning and

significance which are equally obvious. How rarely do we find that

a student of the bacteria, the fresh-water algae, the fungi, the lich-

ens, the liverworts, mosses, or ferns, sees in the varied and beautiful

forms the thread of evolution which binds them all together. And

yet it is true that these lower forms of plants show the method of

evolution more clearly than do the higher plants. These simple

*Condensed from the notes of an oral address.

6 CHARLES EDWIN BESSEY

organisms are more plastic, they respond more readily to their envi-

ronment, than do the higher forms, which have become more stabil-

ized. Here I might speak of experimental results, but these must

be passed by now for want of time. In this address I can only

glance at some of the more marked indications of evolution, as

brought out in their natural classification.

Away down at the beginning of the vegetable kingdom are the

minute single-celled protophytes or water-slimes (Chroococcus,

Gloeocapsa, etc.) in which each plant consists of a bit of faintly

colored protoplasm surrounded by a thin wall. There is no definite

nucleus here, and the only indications of nuclear matter are a few

granules scattered in the protoplasm. We can scarcely conceive of

simpler living things. Near them and a little higher are the blue-

green water-slimes (of the families Oscillatoriaceae, Nostocaceae,

Scytonemaceae and Rivulariaceae) in which the cells cohere in elon-

gated filaments. In the lowest of these the cells are quite undiffer-

entiated, all the cells of a filament being apparently exactly alike,

but in the subsequent families some differences appear. Thus in

the nostocs there are here and there larger cells (heterocysts) among

the otherwise similar cells. In the rivularias the differentiation is

carried a step further, the cells gradually diminishing in diameter

from one end to the other. In all these plants the individual cells

are yet very simple. The walls are a little more defined in the

higher forms, and the nuclear matter, while still consisting of sepa-

rate granules, is a little more condensed.

In the lower green-slimes (Protococcaceae) we find at once evi-

dence of marked improvement. The most significant advance is in

the development of a distinct nucleus. Instead of a collection of

granules lying in the protoplasm we have here a rounded body

sharply set off from the surrounding cytoplasm. Here, also, the

coloring matter of the cell is no longer diffused throughout its proto-

plasm, but it is restricted to one or more protoplasmic masses

(chromatophores) which lie in the colorless cytoplasm.

But the greatest advance is made in the methods of reproduction.

While in the protophytes new plants are formed only by the fission

of the cells, in these green-slimes we find for the first time that cells

may divide into several motile zoospores. These may swim about

for a time, and then come to rest, when they form walls, and are

quite like the cells from which they sprang. This motility is clearly

EVOLUTION IN MICROSCOPIC PLANTS 7

re a device for the distribution of the plants, and in fact each zoospore

____ is to be regarded as a young plant which is able to move away from

the plants in whose midst it originated, and thereby to live in a less

y ae crowded environment. Some of these zoospores, however, do not

_ _ settle down in the manner described, but two meeting, fuse into one

ell, which is consequently larger and stronger, and more capable

of enduring adverse conditions than either of the cells which enter

into its composition. In this simple fusion of zoospores we have

x ____ the beginning of that series of mechanisms which gradually increases

in complexity up to such wonderful structures as the flowers of the

___ lilies, orchids, roses, and thistles. What a distance from this primi-

_ tive sexual mechanism to that of the higher plants; and yet between

these widely separated extremes there is such an easy gradation

that it is not difficult for us to trace the path by which the most

complex flower was evolved from this simple beginning.

The brook-silks and water-flannels (Confervoideae) show again

how from the single-celled condition plants pass easily to the fila-

mentous structure. We have here a repetition of the evolution of

the filamentous plant body from the single cell which we have al-

ready noticed in the protophytes. Here, however, the filaments are

composed of cells which are considerably differentiated. While in

the lower brook-silks the cells as a rule are both vegetative and re-

productive, in the higher forms there is a pretty sharp distinction

between the cells having these two functions, and with this develop-

_ ment we observe the setting aside of some cells whose function is

neither vegetative nor reproductive, but merely mechanical, as in the

“ holdfast cells” of many species.

In many Confervoideae the sexual mechanism closely resembles

that of the green-slimes, consisting of two equal, free-swimming

zoospores, which fuse into a single cell which ultimately develops

into a new plant. In other species the two fusing zoospores (now

called gametes) are differentiated into two sizes, both still ciliated

and motile, while in still others the larger gamete is non-ciliated and

motionless, and the smaller is ciliated and very active. In fact the

activity of the smaller gamete (now called the male gamete) appears

to be increased directly as the female gamete becomes less active,

and when the latter ceases activity altogether the former becomes

extremely active. This change in the activity of the gametes in-

volves the permanent inclusion of the female gamete in the cell in

8 CHARLES EDWIN BESSEY

which it originates, thus affording it some protection before and

after its union with the male gamete. Here is the beginning of a —

series of protective devices which show a gradually increasing com-

plexity, and so admirably illustrate the principle of increasing pa-

rental care as a factor in evolution. Compare, for a moment, the

zygote of Protococcus or Conferva, with no parental protection

whatever, with that of Oedogonium, in which the wall of the parent

cell affords some protection, and then contrast these with the amount

of protection afforded by the parent flowering plant, in the thistle,

for example, where coat upon coat of thick-walled cells surround

the zygote and later the embryo plant.

In the brook-silks we have further illustrations of the modifica-

tion of the plant body through the influence of a particular environ-

ment, whereby from these the group of the pond-scums (Conjuga-

tae) has arisen. Through living in quiet waters some brook-silks

became sluggish in habit. They no longer produce zoospores, since

simple fragmentation of the filaments answers every purpose of

zoospores, and to this sluggishness we may also ascribe the peculiari-

ties of the conjugative sexual act of the pond-scums. From the

filaments of the pond-scums it is a short step to the desmids, most

of whose filaments break up still more easily than do those of the

pond-scums. This easy fragmentation of the filament results in the

unicellular condition of most desmids. By a similar easy fragmen-

tation of the filament the diatoms have been evolved from the pond-

scums, and here the deposition of silica in the cell wall makes neces-

sary some peculiar structural changes, of much complexity, but of

minor morphological importance. Desmids and diatoms are pond-

scums in which the filaments suffer easy solution.

In like manner we may find the origin of the green-felts and their

allies (Siphoneae) from the water-flannels (Cladophoraceae), by a

continuation of the modification which has taken place in passing

from the brook-silks (Confervaceae) to the water-flafnels. While

in the brook-silks the filaments are composed of cells separated by

partitions, in the water-flannels the cell-like segments of the fila-

ments are coenocytes in which there are no partitions between the—

component cells. In the green-felts this lack of partitions is carried

one step further, and as a consequence the filaments are tubular, with

partitions at long intervals only. In this way, we may assume, there

arose the group of plants constituting the order Siphoneae, all of

EVOLUTION IN MICROSCOPIC PLANTS 9

__ whose members-are characterized by tubular, and little-septated, fila-

- ments. Even in those species in which the filaments are compacted

_ into somewhat massive plants, this tubular character prevails.

____ It is instructive to glance at the chlorophyll-less members of the

_ class of the green-algae (Chlorophyceae) which we have been con-

_ sidering. The more important of these are in the families of the

_ water-moulds (Saprolegniaceae), downy-mildews (Peronospora-

ceae), and black-moulds (Mucoraceae). The first of these show

_ comparatively little modification in the structure of the plant body

___ from that of a green-felt, like Vaucheria, The differences are those

which are related directly to the parasitic or saprophytic habits of _

the water-moulds. Thus, of course, there has been a disappearance

___ of the chlorophyll, and a reduction in the size of the plant body,

both of which modifications are such as we should expect under the

circumstances. With these we find, also, the production of number-

_ less, minute zoospores, which may be contrasted with the single,

large zoospore of Vaucheria; yet here again, this is quite what we

should look for in plants which through parasitism or saprophytism

have become dependent upon a particular host or substratum. The

great number of zoospores is directly correlated with the dependent

habit of the plants.

The downy-mildews, which are mainly aerial (that is, non-

- aquatic), and parasitic in the tissues of higher plants, show first of

all those modifications which are due to change of habitat. The

aquatic adaptations are here replaced by aerial adaptations, as seen

in the firmer walls, the substitution, temporarily or permanently, of

conidia for zoospores, and the entire suppression of antherozoids.

When these structural changes are thus accounted for, there remain

few others. In fact the downy-mildews, although parasitic, have

retained so many of the characteristics of the green-felts that their

relationship is most evident. We may regard the downy-mildews

as green-felts which have become parasitic on higher plants, and

which for this reason have become modified as here indicated.

The black-moulds (Mucoraceae) have often been regarded as

related more closely to the pond-scums (Conjugatae), but I am

convinced that they are not so related, but on the contrary that their

origin is to be sought in the green-felts, with which they are evi-

dently related in the structure of the plant body at least. As the

black-moulds are mostly saprophytic, and aerial, their reproductive

10 CHARLES EDWIN BESSEY

apparatus is correspondingly modified. Thus there is a complete

suppression of zoospores, which is effected by the simple device of

the walling in of every little cell (zoospore) resulting from the divi-

sion of the terminal segment (sporangium) of one of the branches.

The zoosporangium has easily been modified into a sporangium con-

taining walled spores. The spores are the homologues of the

zoospores, and doubtless were derived from them. In the sexual

apparatus the greatest modifications have taken place. The game-

tangia, instead of being quite unlike in size and shape, as they are

in the green-felts, water-moulds, and downy-mildews, have suffered

such degenerative modification that they are little unlike. This is,

perhaps, to be correlated with their saprophytic habit, and there is

little doubt that these sexual organs are on the way to extinction.

The infrequency of their occurrence in the ordinary species shows

that they are obsolescent, to say the least.

In passing, I may say that the group of the brown seaweeds

(Phaeophyceae), although related to the green-algae, constitute a

side line ending abruptly with the rockweeds and the kelps, and that

no higher forms have sprung from them. No higher forms can be

traced back to the brown-algae. Their evolutionary line ends with

their own higher members.

Coming back to the line of the green-algae, we find at the

highest point the interesting plants which constitute the genus

Oedogonium. Here we have the highest development yet reached,

especially in the reproductive apparatus; yet this is easily seen to

be based directly upon the structure characteristic of other green

algae. From Protococcus, with its free-swimming isogametes, to

Conferva, Sphaeroplea, and Oedogonium there is an easy gradation

by which from the first very simple sexual act there has evolved

the much higher act as seen in the last genus. In Oedogonium the

gametes are quite unequal in size, and the minute antherozoid is

highly motile, while the large egg is entirely wanting in motility,

and remains within the wall of the egg-cell. After fertilization the

egg becomes a thick-walled zygote, protected somewhat by the sur-

rounding wall of the egg-cell. There is to be observed here some

care of its offspring by the parent plant, inasmuch as the egg is

at no time without protection of the wall of the egg-cell.

This parental care is notably increased in the closely related plants

of the genus Coleochaete, in which, after a fertilization in all essen-

EVOLUTION IN MICROSCOPIC PLANTS 11

_ tials like that-in Oedogonium, the parent plant covers the egg-cell,

__ and with it the egg, with a layer of protective cells, thus constituting

__ @ primitive kind of fruit. Essentially the same structures occur in

_ the red seaweeds, in which the parental care of the results of fertili-

gation is often considerably more marked. Fertilization is no longer

confined to the egg alone, but its stimulation extends to cells and

tissues which are not at all sexual in nature, but accessory, rather,

aa ee oe Se mew Seem He et eerectore oF the

oer Passing to the liverworts and mosses we note that the protective

____ tissue, which in the cases cited grows around the egg-cell only after

_ fertilization, now is developed by the parent plant long before fer-

___ tilization. Yet this notable modification was anticipated in the

3 -stoneworts (Characeae), the highest of the green-algae, where the

egg as it develops becomes surrounded by a protective envelope in

every essential like that which surrounds the fertilized egg of

Coleochaete.

From the liverworts to the lower ferns is but a short step, as is

shown in the essential identity of the sexual organs. The egg-cell

is surrounded before fertilization by a layer of protective tissue ex-

actly as in the liverworts, and so evident is the identity of structure

that egg and protective tissue have long been given the same tech-

nical name,—the “archegone.” In the higher fernworts its sole

modification is that it is sunken for nearly its whole length into the

tissues of the parent, thus affording still greater protection to the

egg before and after fertilization.

Had I the time I might speak of the gradual evolution of the

plant body from the liverworts to the ferns, and flowering plants, in

which step by step simpler structures are modified into those with

greater and greater complexity. I can only say in passing that

from one end of the series to the other there is a close continuity,

and that the complex structures of the thistle and sunflower are

easily derivable from the simple plant body characteristic of the

lower liverworts.

The vegetable kingdom is a unit as to origin; and its multitudes

of forms are connected by an unbroken series of evolutions of struc-

ture into structure. To the discerning mind there are no exceptions,

no forms which are not related to others earlier than they. This

evolution has not been confined to a single line, but has given rise

12 CHARLES EDWIN BESSEY

to a multitude of branches and branchlets of the genealogical tree

which represents the vegetable kingdom. Yet from the lowest there

is a continuous series to each ultimate form, whatever its position, —

just as there is from the lowest to the highest. Evolution has been

in many directions, and while the general trend has been upward, it

has often been outward, and even downward, resulting in diver-

gence, or even degeneration.

TWO GROWTHS OF CHLAMYDOMONAS IN

CONNECTICUT

By FREDERICK S. HOLLIS

Growths of Chlamydomonas in water-supplies, although compara-

tively infrequent, have in several instances been studied and the

presence of an unpleasant odor in the water proven to be associated

with the growths.* The object of the present paper is mainly to

record the presence of two recent growths in Connecticut in water

of rather different character.

The first growth was observed in Walker’s Pond at Burnside on

September 11, 1900, when a sample received contained Chlamy-

domonas to the extent of 14,476 individuals or 5,790 standard units

per c.c., while all other forms present amounted to only 886 standard

units per c.c. On October 4, 1,354 individuals or 542 standard units

were still present, while of other forms there were 293 standard

units per c.c. The water was very turbid and had the marked, un-

pleasant odor due to Chlam

Walker's Pond receives the water of the Hockanum River about

two miles above its junction with the Connecticut. Hockanum

River has its source in the overflow of Shenipsit Lake, the water-

supply of Rockville, a source which at times supports considerable

growths, as, for example, one of about 1,000 standard units per c.c.

of Synura during the present winter. During its course of sixteen

or eighteen miles the river receives considerable contamination, both

of manufacturing waste and sewage. Filter beds have recently been

put in operation for the removal of the South Manchester sewage,

but were not in practical operation for any considerable time during

the period when samples were taken. Averages of chemical analy-

ses for 1900 and two previous years, together with the individual

monthly analyses during 1900, when the growth was observed," are

as follows:

*“ Chlamydomonas in Spot Pond.” F. S. Hollis and H. N. Parker. Jour.

N. EB. W. W. Asn., Vol. XIV, No. 1. “Chlamydomonas and its Effect on

Water Supplies.” G. C. Whipple. Trans, Am. Mic. Soc., Vol. XXI.

* Rept. Conn. St. Bd. of Health, 1900, p. 334.

FREDERICK S. HOLLIS

PARTS PER MILLION

CHEMICAL ANALYSIS, WALKER’S POND, BURNSIDE

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Distinctly

from organ-

isms.

May 29, ’02 | Distinct green

TWO GROWTHS OF CHLAMYDOMONAS 15

_ ‘The second-occurrence was in the water-supply of Winsted. It

_ Was present in the tap water during the last six months of 1go1,

reaching a maximum of 232 individuals per c.c. in the middle of

‘November; and the water during this growth had, in addition to

the usual mouldy or vegetable odor, an unpleasant odor due to the

Chlamydomonas, which was most marked when the numbers were

a greatest, in November. The growth during 1901 did not, I believe,

cause complaint on the part of the consumers, but on May 29, 1902,

‘samples were sent from the Crystal Lake Reservoir and from a tap

supplied with water from this source, to ascertain the cause of a

odor that had been marked for three or four weeks.

The odor of the water was the sharp, unpleasant, and slightly oily,

odor, similar to an odor of putrefaction, which is characteristic of

but perfectly fresh. Chlamydomonas was present to the extent of

970 individual or 242 standard units per c.c., sufficient to give a

considerable turbidity and a greenish tinge to the water. Other

forms amounted to 492 standard units per c.c.

Crystal Lake Reservoir is a natural lake situated 250 feet above

Winsted, the elevation of which was increased 10 feet about 1895,

and the new level maintained by conducting the water of two brooks

into it through a tunnel, about a half mile long, cut through the rock

of the hills. It has an area of 137 acres and available capacity of

390,000,000 gallons.

The Chlamydomonas present in Walker's Pond were about 17%

# long and 14 # broad, corresponding to .4 of a standard unit.

in Crystal Lake Reservoir were somewhat smaller, being

and 11 # broad, corresponding to .25 of a standard unit.

contained some individuals much smaller than this

the great majority were uniform in size. Among

alker’s Pond were a few of the flask-shaped forms de-

r. Whipple in the Brooklyn supply. Those of each

_a cleft or divided chromatophore inclosed in a lorica;

of the chromatophore were smaller and more widely

in the Winsted growth. The contractile vacuole, oil

and starch grains were well marked in those from each

The red eye-spots were far more abundant in the Winsted

16 FREDERICK S. HOLLIS

The flagella of the forms from Winsted were studied with care,

especially with high illumination. While swimming, the form ap-

peared to have one flagellum, or possibly two, projecting forward

about twice the length of the body. These were slightly curved

toward the extremity and had but little motion. Several were seen

in which there appeared to be two of these flagella starting from

the lorica but which were brought closely together about a quarter

of their length forward and appeared beyond this point as one. On

coming to rest, these flagella remained stationary and two other

flagella were brought forward, which, during motion, were curved

backwards and were in such rapid motion as generally to escape

detection. The forms generally rose in the cell during the examina-

tion and rested against the under side of the cover-glass. On

touching the cover-glass lightly, the forms at rest with the swim-

ming flagella projecting forward along with those not used in swim-

ming, quickly curved the swimming flagella back more closely along

the lorica than in the position while swimming. The straighter

flagella, not used in swimming, are not drawn back unless the cover-

glass is tapped harder and, even then, never as completely as the

apparently more flexible swimming flagella.

Associated with each growth were moderate numbers of other

infusoria, considerable numbers of diatoms, and some rotifers. In

the case of the larger rotifers, it was evident that they had been

preying upon the Chlamydomonas.

In filtering the foregoing samples use was made of a column of

sand of the usual depth which passed through a 60-mesh sieve but

was retained by a 120-mesh. The filtrate was found by the use of a

centrifuge to contain Chlamydomonas in numbers which, by com-

parison with an unfiltered sample, were estimated to amount to

nearly twenty per cent of the total number. The numbers given are

corrected on this basis.

a A METHOD OF CONCENTRATING PLANKTON WITH-

OUT NET OR FILTER

By B. L. SEAWELL

plankton studies have always been but approximate

I cise of ie many sourors of error eact within conse

____ trating the organisms into a small volume of water by means of

net or filter. And great difficulties have constantly beset planktolo-

gists in their endeavors to determine the quantitative value of these

The Sedgwick-Rafter method seeks to eliminate the errors of the

_net-filter by filtering measured samples of water (taken by dipping

OF pumping) through a layer of sand, upon which the organisms

are detained, to be afterward removed by washing the sand with

ME ccered portion of Shtered or distilied water. While this

method eliminates many sources of error, it does not avoid several

others, such as the adhering of organisms to the sides of the fun-

nel containing the sand, the passing of organisms between the sand

_ grains, and the adhering of organisms to the sand grains in the

processes of washing and decanting from the sand. Many who

have used the net-filter method are well aware of the host of errors

and difficulties that arise, such as the loss of the smaller planktonts

passing through the meshes of the net, the clogging of the net, with

its concomitant change of coefficient, and the elaborate and uncer-

tain methods of determining the coefficient of the net.

In the early stages of my study of the plankton of Pertle Springs

Lakes, I sought to obviate some of these errors and difficulties by

devising a filter for filtering samples taken by dipping or by the

plankton pump, without its usual filter. The filter succeeded in

removing all planktonts from the water, even those as small as bac-

teria, but there was a slight loss in recovering them from the filter

in the small volume of water representing the final concentration ;

and the time and labor incident to the manipulation of the air-pump

attachment to my filter became a serious objection. To eliminate

the errors and difficulties of the net-filter method, I devised a plan

18 B. S. SEAWELL

which, so far as I have yet detected, is open to but two objections,

both of which are of minor importance and can be overcome. This

plan is the following: The samples are collected by dipping, or by

the use of a plankton pump, without the filter. A measured quan-

tity, say 500 c. c., is placed in a conical flask (Erlenmyer’s) of say

750 c. c. capacity (so as not to make it too deep), 5 c. c. of 40 per

cent formaldehyde added, and the two well mixed at once. All

planktonts will soon die, and all or most of them will gradually

settle to the bottom—none adhering to the sides. At the end of

a sufficient period, say one week, the clear water is carefully si-

phoned off till about 150 c. c. remain. This partially concentrated

sample, after mixing well, is poured into a conical flask of 150 c. c.

capacity, and allowed to settle for another week. The siphoning is

again done, carefully avoiding the drawing off of any of the plank-

ton, and the well-mixed, concentrated sample transferred to a con-

ical flask of 75 c. c. capacity. This flask has a base so small in

diameter that all but about 20 c. c. can be safely siphoned away,

and this final residue, containing practically all the plankton of the

original sample, may be filed for later study in two 10 c. c. vials.

After another week of settling, during which the vials should be

slightly jarred a few times, to prevent adherence of organisms to

the sides, a small portion of the clear fluid may be poured off, and

about half a cubic centimeter of glycerine added, to serve as a

preservative, as the formaldehyde may slowly evaporate. An occa-

sional addition of a few drops of formaldehyde might the more cer-

tainly insure the preservation of the organisms, which are usually

by this method in good condition for microscopic examination.

The chief source of error to be overcome in this method arises

when there chances to be present some organisms, such as Aphani-

somenon, whose specific gravity is not greater than that of water,

and they thus fail to be drawn to the bottom by gravitation. Such

organisms, however, can be secured by filtering the siphonate, and

washing the filter with a small quantity of filtered or distilled water.

Again, alcohol might be added till the specific gravity of the float-

ing organisms is relatively great enough to cause them to sink. Of

course the filtering will lose some organisms, and the alcohol would

bleach them, but neither difficulty is very serious. It might be

objected that this method will not secure sufficient quantities for

accurate volumetric determinations, but this can be overcome by

5 PLANKTON WITHOUT NET OR FILTER 19

fs for tha Giext concentration, and by using sleaderer

gray volumetric measurements. I am at present

s of a plan for overcoming this apparent objection.

__ PREVENTION OF THE PEDETIC OR BROWNIAN ©

‘MOVEMENT IN MILK OR OTHER LIQUIDS

____—sS WITH MINUTE OBJECTS IN SUSPENSION

By SIMON HENRY GAGE

the purpose of photography or for measurement and count-

is very objectionable to have minute particles in constant

x po al For several years efforts have been made to obviate this

__ pedetic or Brownian movement, especially during the photograph-

ing of the globules of milk. None of the inhibitors of the move-

_ ment described in the text-books proved at all satisfactory, but

finally complete success was attained by mixing the milk with a

dilute solution of gelatin. Various mixtures were tried, and all

gave fairly good results, but the following proved entirely satisfac-

tory:

: orn bectericiogy or for food... e+eeees 10 grams.

Slee Gough Giter paper.

_ If the gelatin is acid it may be neutralized with carbonate of soda.

Neutralization is usually, however, unnecessary. This ten per cent

gelatin solution is then mixed with the milk by placing a drop of

the solution on a slide and adding to it a drop of the milk to be

examined. With a scalpel the two are thoroughly mixed, and a

cover added and pressed down to avoid too thick a stratum. The

slide is then placed on a cake of ice or other cold body for fifteen

minutes or more to set the mixture. For other liquids with sus-

pended particles the preparation for examination is exactly the

same.

When the preparation is examined the pedetic movement will not

be found even in the smallest particles. The gelatin solution is so

bland that it does not seem to injure the milk globules in the least.

The only objectionable feature is a slight tendency to agglutinate

the globules ; but no such tendency was observed in the experiments

| made with other liquids containing suspended particles.

ey: es

> Ti

s .

—

raga € q re

—

> STEREOSCOPIC PHOTOMICROGRAPHY WITH HIGH

By F, E. IVES

WITH ONE PLATE

po _ The expert microscopist is able more or less perfectly to determine

- the form of objects with a monocular microscope by focusing suc-

___ essively upon different planes and thus deriving from a series of

__ observations a concrete mental image of the object. The capacity

for visualizing a concrete image out of a series of such observations,

“however, varies greatly with different individuals, depending as it

does not only upon the amount of practice with the microscope, but

___ also upon an inherent faculty which some people possess more than

others. It may be doubted, however, whether even the most gifted

in this respect can generate a concrete mental image of microscopic

objects with anything like the certainty and effectiveness with which

they are presented by the binocular microscope when using low

_ powers. That binocular microscopes are not more used is no doubt

s _ due largely to the fact that only some special forms, difficult of

____ perfect construction and correspondingly costly and troublesome, are

adapted for critical work with the higher powers. But even if we

admit that the trained microscopist can do very well without binoc-

ular vision, we must nevertheless recognize the fact that ordinary

photomicrographs with high-power objectives are defective in that

they represent as spread out upon a single plane details of structure

a which the use of the fine adjustment of the microscope readily show

to belong to different planes. For instance, in a photograph of

a Pleurosigma angulatum showing white dots and “ intercostal mark-

____ ings,” the appearance in the photograph would lead one to suppose

o that it was a representation of a single structure in one plane,

__ Whereas in reality the white dots belong to one plane and the “ inter-

costal markings” to another. The use of the fine adjustment shows

_ that this appearance is due to focusing a plane between white dot

and black dot, and I have long thought that it should be possible

24 F. E. IVES

to see this clearly in a binocular microscope adapted to critical work

with high powers, and also to show it in a stereoscopic photomicro-

graph. The latter feat I have recently accomplished, and in the

belief that further development and understanding of this method

of working may prove of value, I venture to present the results and

briefly describe the procedure adopted.

The three examples of stereoscopic photomicrography in high

powers which I have to show and the only ones I have so far at-

tempted, were made in a single evening, with the same objective

and amplification ;—Zeiss 3 mm. apochromatic objective, 18 com-

pensating eye-piece, 13% in. fixed-focus camera complete in itself,

amplification 1,700, Welsbach light, Cramer isochromatic plates

without color screen.

The objects are Pleurosigma angulatum, Coscinodiscus asterom-

phalus, and a Triceratium. Only a small portion of each frustule

is shown. Pleurosigma angulatum was dry mounted, in cover-glass

contact, and different parts appear in different focal planes owing

to roundness of field of the objective; thus we have white hexagons

on one part and white dots on another, with various effects between,

where the stereoscope shows structure on two distinctly separate

planes. Coscinodiscus shows a membrane with lace-like areolations,

supported by a thick grid which is in most parts hexagonal. Tricer-

atium shows a bossed membrane which appears to be punctured by

groups of round holes in parallel rows, and supported by a hexagonal

grid.

The first essential to the production of these results is that none

of the diffraction pencils which define such minute detail shall be

cut off at the back of the objective. The difference between the two

elements of the stereogram must be due entirely to differences in

the centering of the illuminating cone, and in order to avoid an

exaggerated appearance of relief, the separation of the angles of

illumination must not be greater than it would be in low power

work with an objective of say .30 or .35 n. a., and the central rays

should act in both photographs. The angular aperture of the illu- ~

minating cone for Pleurosigma and Coscinodiscus was only about

.70 n. a., and was decentered, first to the right, for one photograph,

and then to the left, for the other photograph, but altogether so

little that half of the illumination was alike for both photographs.

For the Triceratium I opened the condenser diaphragm until it only

then

decentered

dry

full

* aperture,

* the

he ollges

aha

t one

correctly

is not

Sine |

the

's when

26 F. E. IVES

EXPLANATION OF PLATE

Plate I

APPARATUS FoR STEREOSCOPIC PHOTOMICROGRAPHY

The camera with which the photographs referred to in the text were SEER

It is a simple box camera having a lens the focus of which corresponds

exactly to the length of the box, and is adjustably mounted on a base fitting

against the base of the microscope, in such manner that it may be brought

into use in a few seconds, without disturbing the microscope, and removed

as a rigid whole by a single rectilinear movement of one hand.

The camera swings from centres concentric with the pivot of the micro-

scope, making it quickly adjustable for inclination, and may be used without

even refocusing provided that the microscopist’s vision is emmetropic.

For stereoscopic work, two plates are exposed in quick succession, con-

denser diaphragm decentered to the right for one and to the left for the

other, and are then developed together.

PHYCOMYCETES

A REeEvIsIon oF THE FAMILIES AND A REARRANGEMENT OF

. THE NortH AMERICAN GENERA

By CHARLES E. BESSEY

WITH ONE PLATE

ie ‘The phycomycetes include nine families of fungi (six, to ten,

ny toaiee, or even nineteen according to different authors) which have

a been brought together very largely on account of their evident rela-

_ tionship to the filamentous algae. These families, as here limited,

are the Synchytriaceae, Chytridiaceae, Saprolegniaceae, Cladochy-

triaceae, Ancylistaceae, Peronosporaceae, Mucoraceae, Entomoph-

_ thoraceae, and Monoblepharidaceae. They differ very much in the

Eas be spect an and it is difficult to see on what grounds

they can be regarded as constituting a single group. Some are

rounded cells, which live parasitically in the tissues of higher plants ;

4 others are globular coenocytes with parasitic rhizoids; others are

_ branching, non-septate, coenocytic filaments; while still others are

__ septated filaments consisting of ordinary uninucleated cells. Yet in

the latest scheme of classification, which is found in the third edi-

tion of Engler’s “ Syllabus der Pflanzenfamilien” (1903) the phy-

Ss -comycetes are treated as a natural class of the true fungi (Eumy-

___ Im some recent work on the lower plants it has been necessary for

__ me to examine these and other related forms with some care, and as

__ a result I have been able, as I think, to show that they do not con-

stitute a single group, but that on the contrary they have arisen

through the fungal modification of several algal types. Thus I re-

_ gard the Synchytriaceae as having originated from or near the

__ Protococcaceae in the order Protococcoideae by the adoption of the

parasitic habit. In like manner the Chytridiaceae originated from

or near the Botrydiaceae in the order Siphoneae, and the Saproleg-

28 CHARLES E. BESSEY

niaceae from or near the Vaucheriaceae in the same order of algae.

It seems probable that the Cladochytriaceae, Ancylistaceae, Perono-

sporaceae, Mucoraceae, and Entomophthoraceae are mere modifica-

tions of the Saprolegniaceae, due to increasing hysterophytism. The

Monoblepharidaceae, on the other hand, probably came from quite

a different algal phylum,—the Confervoideae—and their morpho-

logical characters suggest a close affinity with the Oedogoniaceae.

The mutual relationships of these families, and their relationships

to the algae are shown in a general way in the accompanying plate,

where the orders are printed in vertical lines, and the families in

horizontal, the fungi being distinguished by being underlined.

It will be seen that the phycomycetes are distributed among three

orders, viz., Protococcoideae, Confervoideae, and Siphoneae, all of

the class Chlorophyceae, of the branch Phycophyta. It follows that

in any treatment of these fungi their affinities with their algal rela-

tives, rather than their mutual relationships, must dominate their

classification. It is no more possible to treat them as a single mono-

phyletic group, without doing violence to Nature, than it is to treat

the lichens as a single group, or the parasites among the flowering

plants.

The branch Phycophyta includes two classes, Chlorophyceae and

Phaeophyceae, the latter constituting a side line which ends abruptly

with the higher brown seaweeds,—the Laminariaceae and the Fuca-

ceae. The class Chlorophyceae, on the contrary, has not only been

fertile in variations within the class, but from it have been evolved

the higher groups of plants. The order Protococcoideae must be

regarded as representing the primitive type of the Phycophyta, and

from this came the principal phylum now represented by the order

Confervoideae. From the latter it is easy to derive the simpler Car-

pophyta as represented by the Coleochaeteae, and thence the steps

are not difficult to trace to the other classes of the carpophytes

(Rhodophyceae, Charophyceae, Ascomyceteae, and Basidiomyce-

teae), and the lower Bryophyta. The order Confervoideae is thus

to be regarded as the principal phylum leading up to the higher

groups of the vegetable kingdom. It has given rise, also, to two

lateral phyla, represented by the orders Conjugatae and Siphoneae.

The origin of the Conjugatae as a result of increasing sluggishness

of Ulotrichaceae has been sufficiently discussed elsewhere.* By a

*“ The Structure and Classification of the Conjugatae,” in Transactions of the

American Microscopical Society, Vol. XXIII, pp. 145-147.

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 29

decreasing septation of the filament, the Ulotrichaceae gave rise to

the Cladophoraceae, and from the latter the passage is not difficult

to the simpler Siphoneae, and thence to the more complex marine

forms, and along another line which passes through or near the

_ -Vaucheriaceae to a group of half a dozen families of fungi. It is

possible also that from the vicinity of the Ulotrichaceae a genetic

SS fom which the, Phaspenaaase, wore derived

BRANCH II—PHYCOPHYTA

Phycophytea, Spore Tangles

Single cells, threads, or masses, the latter forming a branching

plant with rhizoids ; reproducing asexually (propagation) by fission,

and sexually (generation) by the union of two protoplasts (game-

tes) to form a single spore (zygote) which is often a resting-spore.

Plants from microscopic to large, sometimes a hundred metres or

more in length, mostly aquatic, normally containing chlorophyll in

, but this often obscured by a yellowish or a brown-

ish coloring matter (phycoxanthin and phycophaein), exceptionally

without chlorophyll (as in the hysterophytes).

Key to tHe Crasses.

A. Mostly one-celled or filamentous (rarely stratose or tabular) plants, mostly

chlorophyll-green, or yellowish (colorless in hysterophytes),

Chlorophyceae.

B. Mostly massive or filamentous (very rarely one-celled) plants, brown or

olive-green (no hysterophytes in this class), Phaeophyceae.

Crass CHLOROPHYCEAE

Green Algae

Plant-body from microscopic single cells to large multinucleate,

non-septate, branching coenocytes, or threads of cells, simple or

branched, or rarely plates or tubes of cells; cells containing chloro-

phyll (excepting in hysterophytes) and thus bright green but this

sometimes obscured by phycoxanthin and then yellowish or brown-

ish; asexual reproduction (propagation) by fission of the whole

plant or some of its parts, or by zoospores; sexual reproduction

(generation) by the formation of a zygote (usually within the

parent plant) as the result of the union of equal, undifferentiated

gametes (isogametes), or of unequal male and female gametes

30 CHARLES E, BESSEY

(heterogametes, i. ¢., androgametes and gynogametes), which are —

motile zoospores (planogametes) or motionless protoplasts (aplano-

gametes), as follows: (I) isogamy, (1) both planogametes, (2)

both aplanogametes ; (II) heterogamy, (3) androgametes and gyno-

gametes motile, (4) androgametes (now called antherozoids) mo-

tile, gynogametes (now called oospheres or eggs) motionless.

Typically fresh-water plants (“ fresh-water algae”), but with many

marine species also. Their zoospores and antherozoids usually have

two terminal cilia, sometimes four, or a crown, rarely they are cil-

iated throughout. The hysterophytes are parasitic or saprophytic,

and colorless, and show more or less morphological i 8

(Species, 7,000 to 8,000.)

Key To THE Orpers.

A. Plants all unicellular; generation planogametic, Protococcoideae.

B. Plants filamentous or stratose; generation from planogametic isogamy to

gynogametic heterogamy, Confervoideae.

C. Plants filamentous (or unicellular by solution) ; generation aplanogametic, —

Conjugatae, —

D. Plants tubular or spheroidal coenocytic; generation from planogametic

isogamy to gynogametic heterogamy, Siphoneae.

Order PROTOCOCCOIDEAE

Green Slimes

Plants microscopic, unicellular, but sometimes aggregated into

definite and regular colonies, green (except in the hysterophytes),

with mostly parietal chromatophores, occasionally concealed in old

plants by a red pigment; propagation by cell-division and zoospores,

and the formation of agamic, thick-walled resting spores (chlamy-

dospores) ; generation isogametic, or heterogametic, resulting in the

formation of a single zygote. In many species the vegetative cells,

or even the zoospores (after losing their cilia) divide repeatedly

within a gelatinous mass, and then constitute the “ Palmella stage,”

formerly supposed to be distinct genera, e. g., Palmella, Gloeocystis, —

etc. Many cells of Protococcoideae contain one or more contractile

vacuoles.

Key to tHe FAMILies.

A. Vegetative cells not ciliated,

I. Cells single, or in loose irregular colonies, or in gelatinous masses,

chlorophyll,

1. Not forming zoospores, Pleurococcaceae.

2. Forming zoospores, Protococcaceae.

Cells without chlorophyll, Synchytriaceae.

aggregated into regular colonies, Hydrodictyaceae.

cells ciliated, Volvocaceae.

Family SyNCHYTRIACEAE

cells mostly spherical or ellipsoidal, not ciliated, with-

hlorophyll, growing solitary or merely approximated in the

aquatic or terrestrial plants, each eventually becoming a

fangium, or dividing into several to many zoosporangia;

sropagation by zoospores, and the formation of agamic resting

ores; generation by the union of two equal, free-swimming, unicil-

_— (known for but one genus).

Hesaperes with two clin 1. Olpidiopsis.

SEITE Tecepocnagia free within the host.coll (at act wot grows fast 10

its wall),

1, Resting spore formed by union of two planogametes,

o. 2. Reessia.

2 Resting spores agamic, 3 Olpidium.

ea b. Zoosporangial wall grown fast to that of the host cell,

Gases 4 Pleolpidium,

_-B. Bach vegetative cl dividing into several to many sooyporang, oF oe 0

«Many resting spores,

1. Zoospores with two cilia,

_-—- @ ~Zoosporangia completely filling the host cell, 5. Rosella.

ae b. Zoosporangia only partly filling the host cell, 6. Woronina,

IL Zoospores with one cilium,

: a. Zoosporangia formed directly from the vegetative cell,

7. Synchytrium,

b. Zoosporangia formed by the protoplasm after it has escaped from

the vegetative cell, 8 Pycnochytrium,

4. Olpidiopsis Cornu. Zoosporangium smooth, globose, ellipsoid,

_ OF fusiform, emptying by a tube; zoospores ellipsoid, biciliate ; rest-

32 CHARLES E. BESSEY

ing spores globose or ellipsoid, thick-walled, and roughened or spin-

ose.—Minute parasites in the cells of water moulds (Saprolegnia-

ceae) and pond scums’ (Zygnemataceae). Resting spores 60 to

70 # in diameter.

2. Reessia Fischer. Zoosporangium smooth, thin-walled, almost

completely filling the host cell, emptying by a short or long tube;

zoospores few, very large, uniciliate, rarely developing directly into

new plants, usually acting as gametes and uniting to form a biciliate,

free-swimming body, which penetrates a host cell and there forms a

thick-walled zygote; the latter eventually dividing internally into

smaller zoospores which, escaping by a tube, penetrate other host

cells, and later form zoosporangia.—Minute parasites (two species)

in the cells of Lemna and Cladophora. The cells for several days

after entering their hosts show amoeboid movements.

3. Olpidium A. Braun. Zoosporangium smooth, globose, empty-

ing by a tube; zoospores globose or oblong, with a single cilium;

resting spores globose, thick-walled, smooth, arising by the forma-

tion of a thick wall about the vegetative cells——Minute parasites in

the cells of marine and fresh-water algae, fungi, flowering plants,

pollen, spores, and rotifers. Zoosporangia 15 to 70 uw in diameter;

resting spores 16 to 40.

4. Pleolpidium Fischer. Vegetative cells at first small with a

distinct wall, soon entirely filling, and its own wall growing fast to

the wall of the host cell, then producing numerous uniciliate zo-

ospores which escape through a short tube; resting spores occupy-

ing only a part of the host cell, thick-walled, finely spinose—Minute

parasites (few species) in various water fungi (Saprolegniaceae and

Monoblepharidaceae ).

5. Rozella Cornu. Vegetative cell occupying the whole width of

the host cell from whose protoplasm it is indistinguishable ; zoospor-

angia arising through the successive formation of cross septa, hence

arranged in a single row, each emptying by a very short tube; zoo-

spores reniform, laterally biciliate; resting spores formed by the

division of the vegetative cell into several cells which then round up

and secrete a thick, spinose wall—Minute parasites (two species)

in water moulds (Saprolegniaceae). Zoospores 6 to 8 by 4; rest-

ing spores 20 # in diameter.

6. Woronina Cornu. Vegetative cell through the successive for-

mation of cross septa by the host becoming a row of cells occupying

ice hoor con, Dene ME deace Gocekc crane

+; resting spores arising by the rounding up and division of the

jasm of a cell and-the formation of one or more spherical

s of resting spores, which on germination divide internally to

-zoospores.—Minute parasites in water moulds (Saprolegnia)

green felt (Vaucheria), and rotifers. Zoosporangia 14 to 30/4

pores 2 to 4h by 4 to 5; resting spores 4 to 5.

Synchytrium DeBary. Vegetative cell large, spherical, thin-

ed, often yellow or orange-red, later dividing internally into

, smooth, closely packed, and angular zoosporangia ; zoospores

globo: , uniciliate, escaping through short-necked openings ; resting

spores arising by the formation of a thick wall about a vegetative

. ca several, by the division of the cell.—Microscopic

‘parasites (many species) in the epidermal cells of higher plants,

often producing colored galls. Zoosporangia 24 to 604; zoospores

(2 to 3g; resting spores 30 to 150p.

8. Pyenochytrium DeBary. Vegetative cell at maturity provided

-with a firm wall, its protoplasm escaping through a small opening,

ad secreting a new wall (within the same host cell), then dividing

or into numerous, spherical or angular zoosporangia ; zoo-

ical to elongated, uniciliate, escaping through short,

apillar: openings; resting spore arising by the formation of a

thick, brown wall about a vegetative cell, sometimes several, from

yen of the cell_—Microscopic parasites (of several species)

the epidermal cells of higher plants, forming small galls. Zoo-

25; resting spores 40 to 280 pin diameter.

Order CONFERVOIDEAE

The Confervas

Plants filamentous or stratose, sometimes imperfectly septate, the

34 CHARLES E. BESSEY

ponds and in running waters. The principal families, but one of

which is hysterophytic, are indicated below.

Key To THE FAMILIES.

A. Plants stratose, cells in one or two layers, Ulvaceae.

B. Plants filamentous,

I. Generation isogamic,

a. Plants with true cells (uninucleate),

1. Elongated filiform, mostly simple, Confervaceae.

2. Minute, short filiform, branched, Chroolepidiaceae.

b. Plants with coenocytic segments (multinucleate),

1. Rhizoids lateral, small or wanting, Cladophoraceae.

2. Rhizoids terminal, large, Pithophoraceae.

II. Generation heterogamic,

a. Both gametes biciliated, motile,

1. Several eggs in each oogonium, Sphaeropleaceae.

2. One egg in each oogonium, Cylindrocapsaceae.

b. Only the antherozoids ciliated,

1. Plants green (holophytes), Ocedogoniaceae.

2. Plants colorless (hysterophytes), Monoblepharidaceae.

Family MoNoBLEPHARIDACEAE

Plants filamentous, tubular below, septate above, branching, col-

orless; propagation by uniciliated swarmspores (zoospores) ; gen-

eration by the union of uniciliated antherozoids with large eggs

produced singly in terminal or intercalary oogonia ; antherids usually

near the oogones, subterminal_—Small saprophytic fungi found in

water on decaying plants and animals. But one genus is known.

1. Monoblepharis Cornu. Vegetative filaments cylindrical, of

uniform diameter, branched ; swarmspores with one (posterior) cil-

ium ; oogone enlarged, spherical or clavate, terminal or intercalary ;

antheridia cylindrical, usually just beneath the oogones.—Two spe-

cies, on dead plants and animals in water.

Order CONJUGATAE

Pond Scums

This order is characterized in the place referred to earlier in this

paper. Although some of the phycomycetes (Mucoraceae and

Entomophthoraceae) have been hitherto referred to this order, it is

much more likely that they belong to the Siphoneae, and accord-

ingly they are here so disposed.

e Order SIPHONEAE

= Plants saccate or tubular, often much branched, cory“ or

‘zoospores,—in the air into walled spores ; (2) the contraction of

definite masses of protoplasm into agamic resting spores (aplano-

Spores or chlamydospores) ; generation by the union of (1) ciliated

— (2) ciliated heterogametes, (3) antherozoids with non-

ciliated gynogametes, (4) antherid nuclei (non-ciliated) with non-

te ciliated gynogametes, in all cases producing zygotes.—Fresh-water

__ and marine algae, and many filamentous fungi (hysterophytes), in-

_ eluding many families. Only the more important algae (from the

___ standpoint of this paper) will be noticed.

. _A. Generation, where known, isogamic,

I. Plants small to large, branched, septate, very rarely non-septate

ey (holophytes), Valoniaceae.

IL. Plants minute, clavate, pyriform, or spherical, terminating below in a

“ simple or branched rhizoid, non-septate,

a. Plants green (holophytes), Botrydiaceae.

b. Plants colorless (hysterophytes), Chytridiaceae.

___ B. Generation, where known, typically heterogamic,

} IL, Plants consisting of long, branching, non-septate filaments (in some

hysterophytes very much reduced),

a. Chlorophyll-bearing (holophytes), V aucheriaceae.

b. Without chlorophyll (hysterophytes),

1. Aquatic, parasitic and saprophytic on aquatic plants and ani-

mals,

a. Plants consisting of well-developed free filaments and

endogenous rhizoids, Saprolegniaceae.

b. Plants consisting of endogenous filaments, no rhizoids,

1. Filaments branched, Cladochytriaceae.

2. Filaments simple, sometimes reduced to one or two

cells, Ancylistaceae.

2. Not aquatic,

a. Parasitic in the tissues of higher plants (rarely aquatic,

and parasitic or saprophytic), Peronosporaceae.

36 CHARLES E, BESSEY

b. Saprophytic on various substances or parasitic on other

fungi (rarely aquatic), Mucoraceae,

c. Parasitic in the bodies of insects (rarely in plants, still

more rarely saprophytic), Entomophthoraceae.

Family CHyYTRIDIACEAE

Plants minute, saccate, spherical to elongated, parasitic or sapro-

phytic, colorless, with a simple or branching rhizoid below, the lat-

ter penetrating the host; propagation (1) by the division of the

protoplasm of the plant body into spherical, uniciliate zoospores,

which escape through special openings, or (2) by the transformation

of the protoplasm into an agamic resting spore, or (3) by the for-

mation of resting spores in the rhizoids; generation unknown (or

of doubtful occurrence in Polyphagus).

Key To THE GENERA.

A. Zoospores escaping through simple or tubular openings, rhizoids fine,

usually branched,

I. No rhizoidal enlargement below the plant body,

a. Plant-body epiphytic, 1. Rhisophidium,

b. Plant-body endophytic, 2. Entophlyctis.

Il. With rhizoidal enlargements below the plant-body spherical or

elongated, endophytic or epiphytic,

a. Parasitic, epiphytic, 3. Phlyctochytrium,

b. Saprophytic, only the rhizoids imbedded in the nourishing stratum,

4. Rhisidium,

B. Zoospores escaping through an opening provided with a removable cap;

rhizoids mostly simple, 5. Chytridium.

Anomalous Genus.—Plant with many rhizoids, the slender ramuli penetrating

several hosts, 6. Polyphagus.

1. Rhizophidium Schenk. Plant epiphytic, mostly spherical (or

somewhat elongated), its simple or branching rhizoid penetrating

the host ; zoospores formed in the unmodified plant body, posteriorly

uniciliate, escaping singly by a simple or tubular opening; resting

spores thick-walled, formed by the direct transformation of the

protoplasm of the plant-body.—Species many, parasitic on fresh--

water algae, water moulds, minute aquatic animals, pollen cells, etc.

Plants 15 to 504; zoospores 2 to 3 p.

2. Entophlyctis A. Fischer. Plant endophytic, spherical to pyri-

form, with the branching rhizoids arising basally, or at several

points ; zoospores posteriorly uniciliate, escaping through a tube of

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 37

‘aa -

_ varying length; resting spores thick-walled, formed by the direct

_____ transformation of the protoplasm of the plant-body.—Species sev-

_ eral, in fresh-water algae. Plants 5 to 25; zoospores 3 to 5 #.

___-3 Phiyctochytrium Schroeter. Plant epiphytic, spherical, ellip-

_ soidal, or pyriform, the rhizoidal enlargements spherical, single or

4g several, endophytic or epiphytic, with branched rhizoids ; zoospores

ae escaping singly through the usually terminal opening ; resting spores

____ thick-walled, formed by the direct transformation of the protoplasm

bof the plant-body.—Species several, on fresh-water algae and minute

as ~ animals. Plant-body 10 to 30 by 30 to 35 #; zoospores 2

to 4p.

Vg 4. Rhisidium A. Braun. Plant saprophytic, spherical or ellip-

____ seidal, with an elongated rhizoidal enlargement bearing branched

_____ thizoids which are imbedded in the nourishing stratum ; zoospores

a _ posteriorly uniciliate, escaping in a mass of slime; resting spores

thick-walled and hairy, formed by the direct transformation of the

protoplasm of the plant-body ; in germination the protoplasm escapes

- through a terminal opening in a mass which remains attached to

the empty wall and divides internally into zoospores.—The single

__ species is saprophytic in the slime of fresh-water algae. Plant-body

40 to Box" by 25 to 40x ; zoospores 5 y« ; resting spores 15 to 30/4.

___—__—‘«§. Chytridium A. Braun. Plant epiphytic, spherical or ellipsoidal,

with a short tubular rhizoid (which rarely may have fine lateral

___ branches) penetrating the host cell ; zoospores escaping by the fall-

ing away of a circular cap ; resting spores formed within the rhizoid,

soon becoming as large as the plant-body, thick-walled, in germina-

SIIEES «tube which exkarges tarealeally and produces 200.

__- spores.—Species several, on green and red algae. Plant-body 15

to Gop by 15 to 30/4; zoospores 25 to 40p.

_ Here may be placed provisionally the genus Polyphagus which is

unquestionably related to the foregoing genera, from which in fact

_ it differs only in its peculiar generation, regarding which we may

quite properly question whether it is not after all a case of cannibal-

e) ism, followed by the formation of agamic resting spores in the rhiz-

_ @ids, as in Chytridium.

6, Polyphagus Nowakowski. Plant free, spherical or ellipsoidal,

__ with numerous rhizoids arising at different points, much branched,

_ the ultimate ramuli much attenuated and penetrating the separate

hosts; zoospores ellipsoidal, uniciliate, formed by the escape of the

38 CHARLES E, BESSEY

plant protoplasm into a cylindrical thin-walled sac, and its subse-

quent internal division ; generation (?) by the contact of a rhizoid

of one plant with the body of the other, the result being the trans-

fer of the contents of the latter into a swelling in the former, and

the formation of a thick-walled, oval or irregular resting spore

(zygote ?).—Species one, parasitic on Euglena, one plant often pene-

trating several hosts with its slender ramuli. Plant about 374; rest-

ing spore 20 to 30.

Family SAPROLEGNIACEAE

Water Moulds

Plants minute, aquatic, without chlorophyll, parasitic or saprophy-

tic on animals and plants, consisting of mostly branching, non-sep-

tate (or sparingly septate) filaments, attached by branching rhizoids

which penetrate their hosts; propagation (1) by the formation of

numerous, mostly biciliate, zoospores in the ends of branches set off

by cross-walls, or by the formation of aplanospores, (2) by the

formation of single spherical conidia (“ chlamydospores”); gen-

eration by the formation of one or more eggs in each more or less

spherical oogone, which are fertilized by the transfusion of the

protoplasm of the clavate antherid (usually originating near by)

through slender fertilizing tubes which penetrate the oogone wall.

(Occasionally the eggs develop without fertilization.)

There are two sub-families (considered to be families by some

authors).

I. Filaments not constricted, Saprolegnieae.

IL. Filaments constricted, Leptomitaceae.

Sub-family SAPROLEGNIEAE

Vegetative filaments of uniform diameter, not constricted; zoo-

sporangia cylindrical to ovoid; oogones with one or more eggs.

Key To THE GENERA.

A. Zoospores biciliate,

I. In several rows in the zoosporangia,

a. Escaping from the zoosporangium by a single terminal opening,

1. Dispersing upon escaping from the zoosporangium,

a. Zoosporangia ovoid, 1. Pythiopsis.

b. Zoosporangia cylindrical, 2. Saprolegnia.

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 39

a: Pee —® Eficysting about the mouth of the zoosporangium, 3. Achlya.

]

aay: b. Escaping singly by individual openings, 4. Dictyuchus.

_-—sSTL, Im one row in the zoosporangia, 5. Aphanomyces.

__B, Zoorspores multiciliate, 6. Myrioblepharis.

‘1, - Pythiopsis DeBary. Vegetative filaments slender ; zoosporan-

_ gia terminal, ovoid, the later ones forming laterally below (not

_ within) the older ones; zoospores originating in several rows in

___ the zoosporangium, ovoid, terminally biciliate, germinating directly

after coming to rest ; oogones terminal, each containing one, rarely

two or three eggs.—Species one, on dead animal and vegetable mat-

or.

___—s«2, Saprolegnia Nees. Vegetative filaments stout, unbranched, or

__ paniculately branched; zoosporangia terminal, cylindrical, the later

__ growing through the empty older ones; zoospores originating in

_ several rows in the zoosporangia, ovoid, terminally biciliate, encyst-

ing soon after dispersing, later escaping again as reniform, laterally

biciliate zoospores which germinate upon coming to rest; oogones

mostly terminal, rarely intercalary, each with one or more, commonly

many, eggs.—Species many, on dead, rarely on living, animals.

% Achyla Nees. Vegetative filaments stout, mostly branched;

_ zoosporangia terminal, cylindrical or clavate, the later ones forming

laterally below (not within) the older ones; zoospores originating

_ in several rows in the zoosporangia, ovoid, terminally biciliate, en-

cysting immediately, without dispersing, at the mouth of the zoo-

sporangium, later escaping as reniform, biciliate zoospores which

germinate upon coming to rest ; oogones terminal, rarely intercalary,

each with one or two, commonly many, eggs.—Species many, on

decaying vegetable or animal matter, rarely on living animals.

4. Dictyuchus Leitgeb. Vegetative filaments of medium thick-

ness, somewhat branched; zoosporangia terminal, cylindrical or

clavate, the later ones forming laterally below the older ones ; z00-

Spores originating in several rows in the zoosporangium, and there

encysting, becoming polyhedral by mutual pressure, later escaping

through lateral openings (one for each zoospore), reniform, later-

ally biciliate, germinating upon coming to rest; oogones terminal or

__ intercalary, each with one or many eggs.—Species three, on decay-

ing animal or vegetable matter.

_ §. Aphanomyces DeBary. Vegetative filaments very slender, lit-

tle branched ; zoosporangia terminal, narrowly cylindrical ; zoospores

OE eee a ee ga

: = —— Ss. a . Wh 6 ee

40 CHARLES E. BESSEY

formed in a single row in the zoosporangium, fusiform, encysting

in a cluster about the mouth of the zoosporangium, later escaping

as reniform, laterally biciliate zoospores, and germinating upon com-

ing to rest; oogones terminal or intercalary, each with one egg.—

Species few, on decaying animal matter, and living or dead plants. —

6. Myrioblepharis Thaxter. Vegetative filaments slender, little

branched ; zoosporangia ovoid to spherical, terminal, the later formed

within the older ones, the contents escaping as a single, multiciliate

mass, which later divides into usually four oval or oblong multiciliate

zoospores ; generation unknown.—The place of this singular genus

is problematical, and its position here is merely provisional. Its

single species occurs on submerged sticks.

Sub-family LepromrraceaE

Vegetative filaments divided by constrictions into segments, often

much enlarged below; zoosporangia cylindrical, pyriform, or ellip-

soid; resting conidia often present; oogones with but one egg.

Key To THE GENERA.

A. Plant body of segments similar in size and form,

I. Zoospores biciliate,

a. Zoosporangia cylindrical, 7. Leptomitus.

b. Zoosporangia spherical or ovoid, 8. Apodachlya.

II. Zoospores uniciliate, 9. Gonapodya.

B. Plant body composed of an enlarged basal segment, bearing smaller term-

inal branches,

I. Constrictions in all parts of the plant body,

a. Zoosporangia of one kind,

1. Basal segment of plant body similar in form to the branches,

10. Sapromyces. —

2. Basal segment of plant body of much different form from the

branches 11. Rhipidium.

b. Zoosporangia of two kinds, smooth-cylindrical, and ovoid-prickly,

12. Araiospora.

II. Constrictions only at the base of the zoosporangia and conidia,

13. Blastocladia.

7. Leptomitus Agardh. Vegetative filaments slender, somewhat

stouter below, branched, the segments long-cylindrical ; zoosporangia

cylindrical, terminal, the later ones formed directly below the earlier ;

zoospores ovoid, terminally biciliate, dispersing immediately upon

escaping; generation unknown.—One species, in water containing

organic matter.

a *

=. ae

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 4!

8 Apodachlya Pringsheim. Vegetative filaments slender, simple

or ‘sparingly branched, segments cylindrical; zoosporangia broadly

oval or pyriform, terminal, or apparently lateral by the branching

10. Sapromyces Fritsch. Vegetative filaments with a slightly en-

larged basal segment, umbellately branched above, the segments

___ Similar to but smaller than the basal segment; zoosporangia sub-

____ ¢ylindrical or nearly oval, terminal or lateral ; zoospores discharged

____ im a mass, at first surrounded by a thin membrane, soon escaping as

a tae wo want, cn oogones terminal, or lateral in

___ whorls, pyriform.—Two species, on decaying vegetable matter.

___—s'4. Rhipidium Cornu. Vegetative filaments with a very large

___ basal segment, swollen above, often lobed or branched, bearing many

slender branches ; zoosporangia terminal or lateral on the slender

___ branches, broadly oval ; zoospores discharged i in a mass, at first sur-

__ founded by a thin membrane, soon escaping as reniform, laterally

___ biciliate zoospores; oogones terminal, spherical—Species few, on

aaeme bl

12. Araiospora Thaxter. Vegetative filaments with a much en-

larged, cylindrical, basal segment, from whose summit arise smaller,

_ wmbellately divided branches of similar segments; zoosporangia

_ terminal or lateral, in whorls of two kinds, (1) smooth, broadly

___ ¢ylindrical, or elliptical, (2) spinose, ovoid or pyriform ; zoospores

| discharged in a mass, at first surrounded by a delicate membrane,

___ s00n escaping as reniform, laterally biciliate zoospores ; oogones in

ka or umbels, spherical.—Two species, on Here vegetable

e '1y Te tastocledio Retocs Vegetative filaments with an enlarged

____ ¢ylindrical basal portion (stem) which is much branched above, the

a _ branches rather stout, constrictions only immediately below the zoo-

al CHARLES E. BESSEY

sporangia; zoosporangia terminal or lateral, cylindrical to broadly

oval; zoospores oval or elliptical, terminally biciliate, dispersing

upon escaping from the zoosporangium ; resting conidia terminal or

sub-terminal, bluntly ovoid; generation unknown.—Two species, on

decaying vegetable matter.

Family CLADOCHYTRIACEAE

Plant a reduced, slender, parasitic or saprophytic, much-branched,

non-septate filament, developing terminal and intercalary enlarge-

ments, which become (1) zoosporangia, or (2) resting spores (prob-

ably agamic) ; zoospores spherical or ellipsoid, uniciliate, escaping

through a tube or papillary orifice; antherids and oogones appear

to be wanting.—Minute parasites in the parenchyma cells of aquatic

higher plants, or the slimy secretions of green algae. (In this fam-

ily, which is doubtless related to the Saprolegniaceae, the structural

degeneration, due to their hysterophytic habits, appears to have

affected the sexual reproductive organs more than the vegeenre

filaments. Compare also with Ancylistaceae.)

Key To THE GENERA.

A. Only zoospores known, 1. Cladochytrium.

B. Only resting spores known, 2. Physoderma.

1. Cladochytrium Nowakowski. Vegetative filaments widely dis-

persed in the host, intracellular, giving rise to terminal and inter-

calary spherical or ellipsoid zoosporangia; resting spores unknown.

—Minute parasites (of few species) living in the cells of higher

plants. Zoosporangia 18 to larger; zoospores 2 to 5.

2. Physoderma Wallroth. Vegetative filaments intracellular,

penetrating the walls from cell to cell, giving rise to terminal and

intercalary spheroidal or ellipsoid, thick- and brittle-walled, brown

resting spores; zoosporangia unknown.—Minute parasites (of few

species) living in the cells of higher plants. Resting spores 25 to

35 # by 15 to 304.

Family ANCYLISTACEAE

Plant a reduced, parasitic, colorless filament (sometimes a single

cell, or even a naked mass of protoplasm), at first non-septate, later

dividing into several cells which (1) become zoosporangia and di-

vide into zoospores, which are mostly biciliate, or (2) develop long

germinating tubes which penetrate new hosts, or (3) transform

STRUCTURE AND wanniguabimsnanee OF THE PHYCOMYCETES 43

ats or coqones: the single egg within the oogone is fer-

tilized by means of a tube, resulting in the production of a thick-

walled zygote. (In Diplophysa and Rhizomy-xa the single cell com-

posing the whole plant may form a single zoosporangium, or by

vision, an antherid and an oogone.)—Minute parasites living in

he cells of various aquatic plants, and the root-hairs and epidermal

ells of higher plants. (In this family, which is doubtless related

ST cicas cuore ss nesdunaeeacoigeais seas

i ic habits appears to have affected the vegetative filaments

A. Zoospores present,

___L. Plant body always with a cell wall, zoospores usually biciliate,

_ @. Producing several zoosporangia, or oogones,

1. Plant a branched filament, 1. Lagenidium.

2. Plant an unbranched filament, 2. Mysocytium.

b. Plant body producing but one zoosporangium or oogone,

3- Diplophysa.

BP _ IL Plant body without a cell wall until the formation of reproductive

oS _ €ells; zoospores uniciliate, 4. Rhizomy-xa.

bs No zoospores known, 5. Ancylistes.

e 4 1. Lagenidium Schenk. Vegetative filament at first unbranched

__ and tubular, later with spherical, clavate, or cylindrical branches,

becoming septate, the whole plant eventually consisting of reproduc-

tive cells ; zoosporangia usually broad-cylindrical, straight or curved,

ae the contents escaping by a tube into a bladdery enlargement outside

___ of the host and there dividing internally into reniform, laterally

____ biciliate zoospores; antherids usually cylindrical, lateral or inter-

___ ¢alary, penetrating the oogone wall by a fertilizing tube; oogones

_ __ intercalary, swollen or spheroidal, containing an undifferentiated

_ protoplasm, which becomes condensed after fertilization into a

spherical, smooth-walled zygote.—Minute parasites (of few spe-

__ Gies) in the cells of fresh-water algae, and pine pollen cells. Fila-

_ ‘Ments 3 to 7.54; zygotes 11 to 29 pw.

_ «2 ~Mysocytium Schenk. Vegetative filaments unbranched, at

first tubular, later constricted into a chain of two to many oval or

ellipsoidal cells, the whole plant eventually consisting of reproduc-

___ tive cells ; zoosporangia formed from the unmodified cells, their con-

44 CHARLES E. BESSEY

tents escaping by a tube into a bladdery enlargement outside of the

host and there dividing into reniform, laterally biciliate zoospores ;

antherids and oogones similar, the former penetrating the latter by

a direct fertilizing tube; oogone containing undifferentiated proto-

plasm which becomes condensed, after fertilization, into a spherical,

smooth-walled zygote.—Minute parasites (of few species) in the

cells of fresh-water algae and aquatic worms. Filaments 20m in

diameter ; zygotes 15 to 20,4.

3. Diplophysa Schroeter. Vegetative plant body consisting of

but a single, spherical or ellipsoidal cell which may transform di-

rectly into a zoosporangium; zoospores ovate or spheroidal, unicil-

iate or biciliate, escaping singly by a tube ; generation by the division

of the vegetative cell into two cells, the smaller of which becomes

the antherid, and eventually pierces the other—the oogone—with

a fertilizing tube, the result being a thick-walled zygote——Minute,

and very much reduced parasites (of few species) in fresh-water

algae and water moulds. Antherids 28 to 304; zygotes 68 to 78.

4. Rhizomyxa Borzi. Vegetative plant body at first a plasmo-

dium-like mass of protoplasm, later (1) dividing directly into ovate,

uniciliate zoospores, or (2) forming thin-walled resting sporangia,

which eventually give rise to similar zoospores, these escaping singly

through a short tube; generation by the division of the plant body

into two-walled cells, the smaller of which becomes the clavate

antherid, and pierces the other—the oogone—with a fertilizing

tube, the result being a smaller, thick-walled zygote-—Minute, and

very much reduced parasites (one species) in the hairs and epider-

mal cells of roots of many higher plants. Zoospores 5 to 6; 00-

gones 25 to 40m; zygotes 15 to 20.

5. Ancylistes Pfitzer. Vegetative filaments unbranched, or with

short protuberances, at first tubular, later dividing into numerous

cells ; propagation by means of long “ infection tubes” sent out by

the cells of the filaments, coming in contact with and penetrating

other hosts; zoospores wanting; generation by the transformation

of certain cells into antherids, and others (in larger filaments) into ~

oogones, the former penetrating the latter by a fertilizing tube, re-

sulting in the contraction of the undifferentiated oogone protoplasm

into a spherical or ellipsoid, thick-walled zygote——Minute parasites

(one species) in desmids of the genus Arthrodia (Closterium of

authors). Male filaments 6; female, 10; zygotes 15 to 24.

: STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 45

tn aa ~~ Family Perowosporaceae

‘a, Downy Mildews

ants ieee. without chlorophyll, mostly endophytic, and typi-

1 : (rarely aquatic, and parasitic or saprophytic on ani-

plants), consisting of much-branched, non-septate filaments

their hosts, and from which they send out (into the

water) slender, more or less branched conidiophores ; rhizoids

present; propagation by the formation of conidia which may

ise to laterally biciliate, usually reniform, zoospores (1) imme-

ely (then known as zoosporangia), or (2) after falling (then

yn as metasporangia), or they may germinate after falling, by

ng out a slender tube which grows directly into a new fila-

TE Cenidis termed in chaion, or snaly, not terminating the growth of the

aaa conidiophore,

-_— @, - Zoosporangia, as well as metasporangia, formed, the contents being

_———s—=—=*sésetrunded before the formation of zoospores, 1. Pythium.

__b. Only metasporangia present, the contents escaping as zoospores,

1. Conidia formed in chains, 2. Albugo.

2. Conidia formed singly, becoming lateral by the continued

A growth of the conidiophore, 3. Phytophthora.

eal LE Conkle formed slagty, terminating the growth of the conidiophore,

oh a. Conidiophores several times branched,

1. Persistent; zygote free from the oogone wall. 4. Plesmopara.

5. Sclerospora.

b. Conidiophores simple, terminally swollen, bearing conidia on short

sterigmata, 6. Basidiophora.

46 CHARLES E. BESSEY

1. Pythium Pringsheim. Vegetative filaments slender (without

haustoria) penetrating the cells of the host, saprophytic or parasitic

on animals or plants in water, or parasitic within the tissues of land

plants ; conidia rounded or elliptical, forming singly or in chains on

unmodified portions of the plant, of two kinds (1) zoosporangia,

and (2) metasporangia, emitting their protoplasm in a mass through

a short tube, and then by division forming many zoospores ; oogones

terminal or rarely intercalary, the smooth or rough-walled zygote

free from the oogone wall, and germinating like the conidia, or by

the growth of a tube into a new filament.—Species many.

2. Albugo J. F. Gray (Cystopus Leville). Vegetative filaments

growing parasitically in the intercellular spaces of their hosts, and

sending short, terminally swollen haustoria into the adjacent cells;

conidiophores clavate, grouped in large masses beneath the epider-

mis, which they rupture, bearing terminal chains of conidia, which

germinate, after falling, by the internal formation of zoospores

which escape through a terminal orifice; oogones mostly terminal,

rarely intercalary, the rough-walled zygote free from the oogone

wall, germinating by the internal formation of zoospores.—Species

many, in dicotyledons.

3. Phytophthora DeBary. Vegetative filaments growing para-

sitically in the cells and intercellular spaces of their hosts, and send-

ing their slender, sparingly branched conidiophores out into the air

through the stomata, or directly through the epidermal cells ; conidia

ovate or ellipsoidal, at first solitary and terminal, becoming lateral

by the continued growth of the conidiophore, germinating after fall-

ing, by the internal formation of zoospores, which escape through

the terminal papillary orifice ; oogones mostly terminal, the smooth

zygote free from the oogone wall, and germinating by a tube ter-

minated by a conidium.—Species few, in various dicotyledons, and

the seedlings of conifers.

4. Plasmopara Schroeter. Vegetative filaments growing para-

sitically in the intercellular spaces of their hosts, bearing small haus-

toria, and sending into the air through the stomata numerous per- —

sistent branched conidiophores, which are monopodial, except for the

ultimate branchlets; conidia spherical to ellipsoidal, single, termi-

nating the growth of the branches, germinating by the internal for-

mation of zoospores, or by the extrusion of the protoplasm, which

becomes a walled cell, later growing by tubular prolongation into

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 47

a new Blament; cogones usually terminal, the smooth zygote free

from the oogone wall, and germinating by a tube terminated by a

5. Sclerospora Schroeter. Vegetative filaments growing para-

___ $itically in the intercellular spaces of their hosts, bearing small haus-

___ toria, and sending into the air through the stomata the stout, fuga-

_ gious conidiophores, which are monopodially branched, except for

the ultimate branchlets ; conidia ellipsoidal, single on basally-swollen

Be ultimate branchlets, whose growth they terminate, germinating after

—T ee oF Ee

a ae en 7 .

a falling, by the internal formation of zoospores; oogones terminal,

_ entirely filled by the smooth, spherical zygote, whose walls are grown

fast to the thick, irregular oogone wall; germination unknown.—

Species two, in grasses and joint rushes.

_ 6. Basidiophora Roze & Cornu. Vegetative filaments growing

_ parasitically in the intercellular spaces of their hosts, bearing small

haustoria, and sending into the air through the stomata the un-

branched, capitately swollen conidiophores, which bear at their sum-

mits several short projections (sterigmata) each terminating in a

single, spherical or ellipsoidal conidium ; conidia germinating after

falling by the internal formation of zoospores, which escape through

the terminal capillary orifice ; oogones terminal, the irregularly

_ 7. Bremia Regel. Vegetative filaments growing parasitically in

the intercellular spaces of their hosts, bearing short or clavate un-

branched haustoria, and sending into the air through the stomata

the repeatedly dichotomous conidiophores whose ultimate branchlets

bear terminal, shallow cups, each with several short marginal sterig-

mata, bearing as many ellipsoidal conidia; conidia germinating by

the protrusion of a slender tube through the terminal papilla; oo-

_gones terminal, thin-walled, completely filled by the smooth, thin-

walled zygote ; germination unknown.—Species one, in Compositae.

8. Peronospora Corda. Vegetative filaments growing parasiti-

___ ¢ally in the intercellular spaces of their hosts, bearing large, branched

(rarely small) haustoria, and sending into the air through the

q _ Stomata the repeatedly dichotomous conidiophores whose ultimate

branches are simple ; conidia ellipsoidal, to ovate, without a terminal

papilla, germinating laterally by a slender tube ; oogones usually ter-

minal, larger than the zygote, whose walls are irregularly thickened ;

48 CHARLES E, BESSEY

germination by means of a slender tube.—Species very many, mostly

in dicotyledons.

Family MucoRACEAE

Black Moulds

Plants saprophytic or parasitic, consisting of much branched, non-

septate vegetative filaments, which bear the more or less erect sporo-

phores, the former more or less rhizoid-like and penetrating the

substratum, the latter aerial (in one genus aquatic), cylindrical or

swollen, simple or branched, and often bearing rhizoids below;

propagation (1) by the internal division of the end cells of the

aerial branches (sporophores) into internal spores, (a) in single

enlarged end cells (sporangia) each producing few to many irregu-

larly arranged spores (zoospores in one genus), and (b) in several

or many narrow (or spherical) end cells, each producing one, or

more often, few to many spores in a single row, these set free as a

row of spores (“conidia”) by the early dissolution or fracture of

the sporangial wall (sometimes apparently formed by abstriction) ;

(2) by the formation of thick-walled resting cells (chlamydospores)

in the vegetative filaments; generation by the coming together of

two usually lateral branches, mostly upon vegetative filaments, the

formation of a septum near the end of each, the absorption of the

wall between the united cells, and the fusion of their contents into

a zygote, which eventually becomes thick-walled.

Key to THe GENERA.

A. Plants aquatic, 1. Zygochytrium.

B. Plants not aquatic, living saprophytically or parasitically in the air,

I. Sporophore or its branches with a single, terminal, enlarged, spher-

oidal, many-spored sporangium,

a. Sporangium with a columella,

1. Sporangium-wall little, if at all, thickened,

a. Plant without stolons, sporophores single,

1. Sporophore simple, at least not dichotomously

branched.

a. Aerial filaments smooth-walled, :

§. Glossy, dull, gray or brown, 2. Mucor.

§§. Metallic green or olive, 3. Phycomyces.

8. Aerial filaments thorny, 4. Spinellus.

2. Sporophores dichotomously branched, 5. Sysygites.

b. Plant with stolons bearing rhizoids and tufted sporophores

at the nodes, 6. Ascophora.

_ STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 49

_ —-"@ Sporangium-wall thickened above, thin below, 7. Hydrogera.

a b. Sporangium without a columella, 8 Mortierella.

os. IIL Gporoghore with 2 single terminal, exlarged, many-spored sporangium,

_-—s amd few to many lateral, smaller, few-spored sporangia,

9. Thamnidium.

om Sporophore much-branched, with many small, spherical, one-spored

ag (conidia-like) sporangia on short lateral branches,

a ER us 10. Chaetocladium.

__ IV. Sporophore much-branched, bearing terminal clusters of narrow, few-

a. All of the ramuli bearing sporangia, 11. Piptocephalis.

__b. Some of the ramuli circinate and sterile, 12. Dispira.

many narrow, radiating sporangia (resembling conidia chains),

Re be 13. Syncephalis.

4, Zygochytrium Sorokin. Plants aquatic, saprophytic, the pale

yellow filaments erect and irregularly branched, attached to the sub-

:, - Stratum by short, irregular rhizoids ; sporangia solitary on the ends

____ of the branches, without columella, opening by a circular lid; zoo-

‘spores spherical, uniciliate; zygote spherical, thick-walled, red,

formed by the union of lateral branches from the erect filaments.—

Be ‘One species, on dead flies, gnats, wasps, wi in water.

2. Mucor Linne. Plants saprophytic, the vegetative filaments

_ smooth-walled, abundant, and penetrating the substratum, rhizoid-

a Tike and tapering at the extremities, at first white, later dusky or

__ blackish ; sporophores erect, simple or monopodially or sympodially

branched sporangia many-spored, spherical or pyriform, thin-

___ walled, mostly dark-colored, with a large columella ; spores spherical

or elliptical, mostly dark-colored, escaping by the irregular rupture

Of the sporangium wall; zygotes formed in the vegetative filaments

(rarely found).—Species many, on organic matter.

__-3 Phycomyces Kunze. Plants saprophytic, the vegetative fila-

_ ments smooth-walled, abundant, and penetrating the substratum,

__ thizoid-like and tapering at the extremities ; sporophores erect, sim-

_ ple, metallic-green or olive ; sporangia large, many-spored, spherical,

_ thin-walled, brownish, with a large, pyriform columella; spores

| ellipsoid, yellowish, escaping by the dissolution of the sporangium

wall; zygotes formed in the vegetative filaments, the adjacent cells

_ With dichotomously branched, dark-brown outgrowths.—Two spe-

_ ies on oily or decaying organic matter.

50 CHARLES E. BESSEY

4. Spinellus Van Tieghem. Plants parasitic, composed of deli-

cate filaments penetrating the host, and brown, thorny, irregularly-

branched, aerial filaments which bear the sporangia and sexual cells;

sporophores simple ; sporangia large, spherical, with a globular colu-

mella; spores fusiform to spherical, escaping by the dissolution of

the sporangium wall; zygote barrel-shaped, smooth, formed in the

aerial filaments.—Species few, on agarics.

5. Sysygites Ehrenberg. Plants saprophytic, composed of deli-

cate filaments penetrating the substratum, and dichotomously

branched aerial filaments which bear the sporangia and sexual cells;

sporophores dichotomously branched, eventually septated; sporangia

spherical, with a hemispherical columella; spores round or ellipsoid,

escaping by the early dissolution of the sporangium wall; zygotes

spheroidal and smooth, formed on specially developed dichotomously _

branching aerial filaments——One species on decaying agarics and

other large fungi.

6. Ascophora Tode. Plants saprophytic, composed of delicate

filaments penetrating the substratum, and dichotomously branched

aerial filaments which send out stolons in all directions, these bear-

ing rhizoids and sporophores at the nodes; sporophores non-septate,

simple, tufted, swollen just below the nearly spherical sporangium ;

columella hemispherical, collapsing and becoming umbrella-shaped

when old; spores spherical or somewhat angled, escaping by the

early disappearance of the sporangium wall; zygotes spherical or

nearly so, with a thick, warty, dark-brown wall, formed in the mass

of vegetative filaments in or on the substratum.—Species few, on

organic matter and decaying substances.

7. Hydrogera Wiggers (Pilobolus Tode). Plants saprophytic,

composed of much-branched filaments with tapering, rhizoid-like

ramuli, penetrating the substratum, without stolons, and producing

erect, simple, terminally enlarged sporophores, which arise from

swollen portions of the vegetative filaments; sporangium terminal,

hemispherical, with its wall thickened, black, and cuticularized

above, and thin and evanescent below; columella small, conical ;.

spores spherical or ellipsoid; zygotes spherical or barrel-shaped,

formed in the mass of vegetative filaments.—Species few, on excre-

ment.

8. Mortierella Coemans. Plants saprophytic, composed of very

slender and weak, branching filaments penetrating and running over

STRUCTURE AND CLASSIFICATION OF THE PHYCOMYCETES 5!

the substratum, spreading by many stolon-like anastomosing

branches, more or less septate when old; sporophores erect, single

or tufted, simple or branched, mostly colorless, sometimes with

thizoids below ; sporangia terminal, spherical, thin-walled, without

columella; spores mostly spherical or elliptical, colorless, variable

in size, escaping by the early rupture of the sporangium wall ; zygote

formed in the mass of vegetative filaments, spherical, surrounded

by the dense growth of filaments arising from the adjacent cells —

; ‘many, on excrement and other decaying matter.

9. Thamnidium Link. Plants saprophytic, composed of much-

SUT hiss: Mcmente- scastrating. Ge. etheteatom, without

‘stolons, and producing erect, branched sporophores; sporangia of

two kinds, (1) larger, single, terminal, many-spored, with a colu-

_ mella, (2) smaller, clustered, lateral, few-spored, without a colu-

_ mella; spores alike, spherical or ellipsoid, escaping by the disap-

_ pearance of the sporangium wall ; zygotes spherical or barrel-shaped,

thick-walled, dark brown or black, formed in the mass of vegeta-

___ tive filaments.—Species few, on excrement and other decaying mat-

__—s*10. Chaetocladium Fresenius. Plants parasitic or saprophytic,

composed of slender, colorless, much-branched filaments, attached

_ to their hosts by clusters of short, thick rhizoids (haustoria) ; sporo-

____ phores rarely erect, mostly creeping, at length septate, repeatedly

branched, each branch ending in a long-pointed sterile thread;

conidia-like sporangia spherical, single (not in chains) approxi-

___ mated in botryoid clusters, on short lateral branches ; zygotes formed

on the vegetative filaments, spherical, naked.—Species few, on other

_ _Mucoraceae.

‘14. Piptocephalis DeBary. Plants parasitic, consisting of slen-

der, branching filaments, producing here and there dense clusters

_ f rhizoids which penetrate their hosts, sometimes producing stol-

ons; sporophores erect, dichotomously branched, septate and brown-

ish with age, the ultimate ramuli not terminally enlarged ; “ conidia ”

cylindrical or spherical, in radial chains clustered on the ends of the

famuli ; zygotes formed on the vegetative filaments, spherical, naked.

—Species few, on other Mucoraceae.

_ 12. Dispira Van Tieghem. Plants parasitic, consisting of slender

___ branching filaments attached to their hosts by large rhizoids ; sporo-

_ Pphores erect, septate, colorless, much branched, some of the ulti-

52 ‘CHARLES E. BESSEY

mate ramuli sterile and circinate, the others terminally swollen and

papillate, bearing numerous short, I-septate sterigmata, each devel-

oping terminal clusters of “conidia”-chains of two ovoid hyaline

cells ; zygote spherical, brownish, formed by the union of two con-

tiguous cells in a filament (in the single known case the filament

attaches itself to its host, cuts off a swollen cell next to the host,

this soon emptying its contents into the adjacent cell, which then

becomes a zygote).—Species few, parasitic on other Mucoraceae.

13. Syncephalis Van Tieghem and Le Monnier. Plants parasitic

(rarely saprophytic), consisting of very slender, branching and

anastomosing filaments, producing numerous clusters of rhizoids

which penetrate their hosts; sporophores stout, erect, mostly un-

branched, enlarged above, and bearing a cluster of forked rhizoids

below ; “ conidia” cylindrical to fusiform, in many radiating chains

clustered on the enlarged summit of the sporophore; zygote sphe-

rical, naked, formed on the vegetative filaments.—Species many,

on other Mucoraceae (occasionally on excrement).

Family ENTOMOPHTHORACEAE

Insect Fungi

Plants parasitic in the bodies of insects (rarely endophytic or

saprophytic), consisting of much-branched, tubular, mostly endo-

zoic, filaments, eventually septate, and often separating into distinct

segments, sometimes bearing rhizoids which attach the host to the

substratum; propagation by the abstriction of single conidia from

the ends of short, aerial filaments and by the asexual formation of

resting spores in the vegetative filaments ; generation (mostly within

the host) by the union of two approximate or adjacent cells or seg-

ments, and the development of a thick-walled zygote.

Key to THe GENERA.

A. Parasites of insects, 1. Entomophthora.

B. Parasites of plants, :

I. In the cells of fern prothallia, 2. Completoria.

IL. On higher fungi, 3. Conidiobolus.

C. Saprophytes on excrement, 4. Basidiobolus.

1. Entomophthora Fresenius. Vegetative filaments growing

mostly in the soft interior tissues of insects, in some cases growing

~ eapierie Lohde. Vegetative filaments growing in the cells

_ of fern prothallia, at first tubular, later with many irregular

__ branches ; conidiophores simple, penetrating the cell wall, each form-

ing a single ovoid conidium ; asexual resting spores produced by

_ the contraction of the protoplasm of a vegetative cell, and the for-

_ mation of a thick wall_—One species, not yet reported for North

America.

___-—« 3. Conidiobolus Brefeld. Vegetative filaments growing parasit-

____ ically on higher fungi (rarely saprophytic), well developed, much

___ branched, more or less septate, and eventually separating into seg-

_____ ments; conidiophores erect, simple, clavate, each bearing a single,

void conidium; zygotes thick-walled, spherical, formed by the

oS union of two segments of the vegetative filaments.—Species two,

4 Basidiobolus Eidam. Vegetative filaments growing sapro-

_ phytically on excrement, well developed, much branched, at first

continuous, later septate ; conidiophores erect, clavate, each bearing

a single terminal, ovoid conidium; zygotes thick-walled, spherical,

formed by the union of two adjacent filaments—Species two, on

_____ the excrement of frogs and lizards.

NOTES ON THE SEXUAL ORGANS OF SAPROLEGNIACEAE, PERONOSPORA-

CEAE, MUCORACEAE, AND ENTOMOPHTHORACEAE

___¥. Typical antherids and oogones occur in the aquatic holophytic

_ plants constituting the family Vaucheriaceae.

, 2. The antherids and oogones of the Saprolegniaceae are so modi-

_ fied on account of their parasitic habit, as to result in the suppression

_ Of the antherozoids, and the transfer of the contents of the antherid

___ to the oogone directly. The same has occurred in the Peronospora-

54 CHARLES E, BESSEY

ceae, here perhaps in part due to the fact that fertilization takes

place in the air (not in the water).

3. The sexual organs of the Mucoraceae are of the type of the

Saprolegniaceae, as modified in the non-aquatic Peronosporaceae,

and like them they are lateral diverticula each of which cuts off an

end cell (antherid and oogone).

4. The sexual organs of the Mucoraceae are in process of extinc-

tion; in the ontogeny of each plant they never fully develop, and

are no more than mere rudiments (anlagen) ; phylogenetically they

are not rudiments but vestiges.

5. These physically under-developed and but little differentiated

sexual organs of the Mucoraceae conjugate prematurely, before the

oogone is ready for fertilization, and the act is merely a fusion of

the nearly undifferentiated gametes. At the instant of conjugation

there is no oogone proper in which a zygote can form, but this pre-

mature conjugation stimulates the growth of the egg cavity (0o-

gone, zygogone).

6. The sexual organs of the Entomophthoraceae are similar to

those of Mucoraceae, and are likewise in process of extinction.

EXPLANATION OF PLATE I

Cart SHowinc THE RELATIONSHIP OF THE PHYCOMYCETES

The names of the orders are printed in vertical lines and the families in

horizontal. Those of the fungi are underlined.

— .

avaqioawasnood

OE ee

bs ti

-“e-aeece

Bece mecccea oeore=

F THE LIVER IN SUS SCROFA DOMESTICUS

PANCREAS

Published under a grant from the Spencer-Tolles Fund

_By DAVID C. HILTON

WITH FOUR PLATES

TaBsLe or CoNTENTS

SERRE EEE EEE EEE ER ETE TETHER

SRE EER ERE EET TT HH

protonic wall SRR ee

Bos bee cece veecewcccceeesces eee eee eee eee eee eee ee euse

TERE REET Te

Be cv ccccvscveccesccsccsecses ee ee eee

p Peer Terre er eee ere rere rere ee eee ere ee eee ee ee

4 Comparisons of results with those of other authors...............

1. The simple, smooth wall of the proton..........cscccscsecceesees

A. Basic Sia ch chvecseddacdbcedcecccdesve eee eee erent estes

ag B. Development Pee eee eee Cee eT eee Te eee eee ee eee ee ee ee eee eee

___D. Relation of vascular spaces to protonic structure.............

. The vaso-formative cells of Van der Stricht................ce005

B. Papilla formation (Exuberant evaginations) .......... 00.000

EARLY MORPHOGENESIS AND HISTOGENESIS

s Notes oN THE MORPHOGENESIS OF THE VENTRAL

SSS PSSSIRAPILAy SRSSSIREMSIYY Si

56 DAVID C, HILTON

EV. Lilet Of emmbeges. 55 ss 0s.00s0s003echsand eae miaeneukann dessin 84 1

VY. Bioanal eas svc oc os os cccncuve oss spice hbupembeiueeedceas sca ;

VI. Explanation of plates.......6ccicccsesccokeel sueeiuecneh ceacbaueee 86 d

INTRODUCTION ’

The material used in this research was selected from a collection ,

of five hundred embryos obtained at the packing houses in South |

Omaha, Nebraska. The embryos ranged in length from 4 to 25 }

mm. They were taken from the warm uteri, and, while their hearts

were beating, placed in killing and fixing reagents. For this pur-

pose different reagents were used, such as picro-nitric acid, chromo- :

nitric acid, Zenker’s fluid, formol-acetic acid-alcohol mixture, and

10 per cent formaldehyde. The specimens were hardened in 75 |

per cent alcohol.

The approximate age and the degree of development of each

embryo were determined by counting the protovertebrae and com- ,

paring the count and general appearance of the specimen with |

Keibel’s tables and charts. Measurements furnish very inaccurate ;

data, and are not to be relied on.

Sections of series P and K were cut 6m thick, the others, toy.

In all, twenty-five series of sections were studied. Those from

which drawings are produced in this paper were stained as fol-

lows:

Series X* (Dr. Peterson’s)—borax carmine.

Series D—Grenacher’s alum carmine.

Series G—Ehrlich’s acid haematoxylin, picric acid.

Series J—Ehrlich’s acid haematoxylin.

Series P—borax carmine, picric acid.

Series K—Ehrlich’s acid haematoxylin.

Series S—Grenacher’s alum carmine, picric acid.

All of the above series were killed and fixed in formol-acetic acid-

alcohol solution. Eleven models of the hepatic proton were con-

structed at a magnification of 100 X.

Aside from my own material, I have had access, through the

kindness of Dr. Peterson, of Omaha, Nebraska, to his sections and

models of Series X* which furnished the most primitive stage

studied.

I would not close this introduction without expressing my sin-

cere thanks and obligation to Dr. Henry B. Ward, for several years

Se ee

‘

;

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 57

~ my teacher, ‘whose kindness and helpful suggestions have made this

: — both pleasant and profitable.

MorPHOGENESIS

7 . The simple wall of the proton

a SN a carck, sevens tae uaiioelogle changes thet

the proton of the liver suffers, there are four distinct stages of form-

| _ €ondition under which it is convenient to discuss the subject.

____ Tm the first stage, the proton is a modified strip of the ventral

i epithelium of the foregut bordering the yolk-stalk; no part of the

____ proton forming as yet an evagination of the enteric canal. In the

__ second stage, a part of the proton forms a shallow evagination. In

» third stage, a greater proportion of the proton is included in

(aco pe eile at

the foregut, but no part of the proton borders the yolk-

fourth stage, the entire proton is an evagination with

ior surface, and it opens by a more or less con-

lumen of the foregut.

At this period of growth, the ventral wall

it lies dorsad to the heart extends approxi-

q in an antero-posterior direction (i), but where it approaches

the posterior end of the sinus venosus (sv) it arches ventrad, gradu-

es ® doreo-ventral sttitude posterior to the heart (ht)

postero-ventrad to the sinus venosus. Here the intestinal wall

_ constitutes the lining of the anterior inner surface of the yolk-stalk

where it opens into the intestine (ys). At about the level of the

ventral aspect of the heart the wall of intestinal epithelium, having

tapered to a very thin margin, becomes continuous with the delicate

__ extra-embryonic lining of the yolk-stalk (bys). That portion of

the ventral wall of the foregut described as lying behind the heart,

__ and assuming an approximate dorso-ventral direction, is the earliest

rudiment of the liver observed. Its greatest thickness is two to

_ three times as great as that of the ordinary epithelial lining of the

_ intestine, and the point at which the intestinal epithelium thickens

_ abruptly, caudad to the sinus venosus, defines the dorsal border of

__ the hepatic proton (bd).

_____ Between the proton and the heart is an area filled with embryonic

connective tissue rich in blood supply. This vascular area of tissue

rey

Heli

gik

‘

58 DAVID C, HILTON

is the septum transversum, and that part of it immediately con-

tiguous to the proton is called the prehepaticus (ph). The liver

finally comes to be completely within it, and derives its interstitial

tissue therefrom.

The sinus venosus is the largest blood space in the septum trans-

versum and is dorsally situated within it (Figs. 11, 12, and 13,

sv). Anteriorly it opens into the heart. Posteriorly it comes in

close proximity to the dorsal portion of the anterior surface of the

proton (Figs. 11, 12, and 13, ds). On each side of the median

plane a short extension of the sinus projects posteriad. Each pro-

jection is formed by the union of two veins,—the vitelline and

umbilical.

The umbilical veins extend in an antero-posterior direction, each

lying in the lateral body wall (Fig. 14, vw). The veins of this

pair have scarcely any extensions into the septum transversum.

The vitelline veins extend antero-posteriad in the extreme dorsal

portion of the septum transversum. There is one at each lateral

aspect of the intestine, and for a great part of their length above

the liver proton, they are included in folds of the septum transver-

sum which project dorsal into the pleuro-peritoneal cavity (Fig.

14, vv). Large sinus-like extensions from the ventral surface of

this latter pair of veins dip into the septum transversum and ramify

it with a vascular network (Figs. 14, 15, and 16, sn; also other fig-

ures). The higher the stage of development, the more the branches

of this network increase in relative number and diameter. Close to

the wall of the proton, the vascular spaces are large and more or

less sinus-like. These sinuses decrease in size and increase in

number toward the more peripheral region of the septum transver-

sum, where they appear more like capillaries.

Minot (98) gives an account of a similar sinus-like structure of

the vascular system in the mesonephros of the pig embryo. The

vascular spaces in the septum transversum about the proton of the

liver agree with the vessels described by Minot in respect to com-

munication, size, irregular curvature, and the make-up of their walls

which follow the surface of the liver rods rather than their own and

independent curve as is characteristic of true capillaries. Minot

states that there is little mesenchyme between the vessels and the

tubuli of the mesonephros. About the proton of the liver and the

vascular spaces surrounding it there is considerable mesenchyme,

— Ss

——

2% : MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 59

caer

Sip ces pranceeet SALES tes tare xt

mus venosus ventrad into the yolk-stalk where it ends, after taper-

en Its border, on the one hand, wire a

Eta tice wade Wate hls’ ante kaa atin

lining of the yolk-stalkk (Fig. 11, bys). Of its two

or lumen surface is in contact with the em-

_ Stage 2 (Figs. 1, 1a, 1b). The principal difference between

_ this stage and stage 1 may be grouped under changes in the thick-

ness, the extent, and the form of the proton.

ds teaoet dra sucserite and goctnonsaniay oes The

inten! pitta long the tree border, the wal

thinner than elsewhere. eos setae ane

Tle

| the original. This increase has occurred by virtue of two

aka Gh Wa & ice ee

k-stalk border of the proton and of the intestine lying

it, slants postero-dorsad from its more anterior portion.

60 DAVID C. HILTON

As to the form of the proton in this stage, a very noteworthy

consideration is that to describe it in the terms of a shallow out-

pocketing of the enteric canal is incomplete. Cut the proton by a-

plane transverse to a median sagittal section of it, in a line drawn

from the most anterior point on its dorsal border where it is con-

tinuous with the intestine, to the most anterior point on the free

border at the yolk-stalk. Such a plane is inclined dorso-ventrad

and slightly posteriad (/d). This divides the proton into two por-

tions. The part anterior to the plane describes a shallow basin-

like evagination, which in this model is imperfect on account of the

excessive anterior (sinus) depression (ds), although it is seen

clearly in other models. The broad mouth of the evaginated por-

tion coincides with the plane, opens posteriorly, and is inclined very

slightly dorsad. That part of the proton posterior to the plane is

not any part of an evagination. It consists in a posterior alar con-

tinuation of each lateral wall of the evagination (ea).

There are the dorsal and the posterior borders. The former ex-

tends approximately in an antero-posterior direction. It is U-

shaped; the convexity of the U constituting the dorsal border of

the anterior surface, and each limb of the U making up the dorsal

border of the lateral surface of its own side. This border is at-

tached in that throughout its entire length, the proton is continuous

with the intestinal wall.

The latter border is divided into an upper, attached, and a lower,

free, portion. Since the difference between the structure of the

hepatic tissue and the ordinary intestinal epithelium fades out by

degrees posteriorly, it is difficult to determine by a line exactly where

the proton ceases and the intestine begins. But this line defining

the attached part lies approximately dorso-ventrally on each side,

from the intestine above to some point on the free border below.

The model (Fig. 1) includes an area about as far posteriad as

the location of this border (bp). The lower, free part consists in

the thin edge of the proton at the yolk-stalk. It is U-shaped.

The arch of the U constitutes the posterior boundary of the ventral

surface of the proton. Each limb of the U extends postero-dorsad

on its respective side, to that point where it meets the ventral end

of the attached portion, being here continuous with the intestinal

yolk-stalk border.

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 61

___—s-' There-are the internal and external surfaces which have been

Te hecreaned greatly in extent, and have become subdivided into a ven-

____ tral, an anterior, and two lateral aspects. These surfaces possess

a few characteristic features. The anterior surface presents a deep

indentation (sinus depression) across its dorsal portion (ds). It

___ is observable in most of the specimens, but not in all (Figs. 1 and 2).

This indentation when present subdivides the anterior portion of

‘the proton into two lobes, of which the one lying dorsad to the

___ indentation is the smaller. The lateral surfaces vary considerably

im contour. At their anterior and ventral margins they arch into

_____ the corresponding surfaces. Their two remaining margins are con-

tinuous directly with the intestine, except the free yolk-stalk portion

of the posterior margin. The ventral surface, in most cases, is

convex where it arches dorsad into the anterior and lateral surfaces,

___ and concave antero-posteriorly where its free border flares down-

ward slightly at the yolk-stalk.

' According to most of the models, the diameter of the proton from

the ventral border of the intestine above, to the ventral surface of

the proton below, is much greater than its dimensions from side to

side, although this relation is sometimes reversed (dl, dvd).

Three important concomitant changes have taken place with this

increase in the number and the extent of borders and surfaces, and

enter as factors in producing the difference in form and location

between the proton of stage 1 and of stage 2. First, the down-

growth of the wall of the enteric canal along the lateral as well as

along the anterior inner surface of the yolk-stalk, and the subse-

quent differentiation of the same from anterior to posterior into

hepatic tissue, has occurred. Second, the lateral aspects of the

U-shaped free border have approximated each other and fused

progressively from before backward. As a result of this fusion,

the ventral surface of the proton has been brought into exist-

ence and constantly increased by posterior extension. Third, the

“posterior recession of the yolk-stalk on a plane with the newly

developed ventral surface of the proton, and the growth of the

prehepaticus beneath this surface have proceeded (compare Figs.

11, 12, and 13, ph). On account of these changes, the proton which

in stage 1 could be said only to lie upon the prehepaticus, begins to

lie partially within it.

62 DAVID C. HILTON

The contours of the internal and external surfaces coincide in

general, although there are promiscuous variations in the mural

thickness, aside from the regular variations previously noted. There

are certain small, sharply-defined projections on the external sur-

face, which will be described under histogenesis.

A more matured condition of the proton in this stage differs

slightly from the preceding proton in that the features of special

interest in the foregoing specimen are more obvious in this one

(Figs. 2, 2a, and 12). The most important new feature seen

in this model is the anterior constriction. It is indicated by a con-

striction at the dorsal border of the anterior surface immediately

beneath the intestine (ca). It is the beginning of the progressive

separation of the proton from the intestine. By virtue of the con-

stricting process and the extension of the ventral surface, the

evaginated portion is deepened and enlarged. The enlargement

has taken place partially at the expense of the lateral alar exten-

sions, in so far as they have been incorporated into side walls of

the evaginated increment. The more sacculated the proton be-

comes the deeper it is embedded in the septum transversum.

Stage 3 (Figs. 3, 3a, and 13). The ultimate extent to which

the intestinal wall differentiates into hepatic tissue is nearly, if not

wholly, determined at this stage. The remarkable recession of the

yolk-stalk has been accompanied by an increase in the antero-

posterior length of the ventral surface of the proton, by way of

fusion, such as is described in the foregoing stage. Of great sig-

nificance is the fact that the differentiation of the ordinary intestinal

epithelium into hepatic structure, has not kept pace with the reces-

sive migration of the yolk-stalk. Therefore, the free border of

the proton is no longer existent. In its place is the line of union

of the proton with the intestine lying posteriorly between the hepatic

tissue and the yolk-stalk (i). Accordingly, the mouth of the evagi-

nation does not, as in the previous stage, open into the space where

the lumina of the intestine and of the yolk-stalk conjoin, but into

the lumen of the foregut proper.

On the ventral surface of the model, there are three depressions

extending transversely across it. The most posterior one (dv*)

indicates the locality where the foregut dips slightly into the yolk-

stalk. The middle one (cp) indicates the region where the ventro-

posterior limit of the proton passes into the ordinary epithelium of

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 63

ge ian steel te (dv*) is an incipient constric-

rs Pent On pertencate: Cevelogs ‘alk ox: rocet

rr Esc cvetica in. hace COMMU Necicaton, foe, tea fest

¢ as that convexity of the ventral protonic surface lying between

anteric ee ene ventral Copremeeey) In the previous stages,

form-conditions of its presence are not only lacking, but the

tissu Tid of iets wholly uaforinel or-cnly. partially existeit :

since all or nearly all of the intestinal epithelium which can be

‘ecognized as part of the hepatic proton partakes of the characteris-

‘Structure of the pars hepatica. In view of the fact that the

gall-bladder occupies the ventro-posterior part of the proton, it is

clear that the pars hepatica is formed before the pars cystica. The

wall of the pars cystica is somewhat thicker than that of the pars

hepatica, and represents about one-third of the mural area (Figs.

ee eid

__ The mid-ventral depression (posterior constriction), is the coun-

erpart of the anterior constriction already mentioned. The latter

‘more pronounced than in stage 2. The deepening of these sepa-

ts the proton from the intestine more and more. They are con-

nected by a more or less perfect longitudinal furrow on each side,

inning posteriad and finally ventrad. These furrows are the lat-

eral aspects of the zone of constriction demarking the proton from

the intestine.

____ Not only has the ventral wall of the proton extended posteriad,

but that region of it posterior to the most anterior ventral depres-

sion, including as it does the ventral surface of the pars cystica, is

. “Row inclined slightly dorsad, antero-posteriorly. This dorsal in-

_ ¢lination becomes greater and greater in subsequent development,

until it is practically dorso-ventral in direction. tpse peel geet

a Oe tee ecto be plane in the manner that those of

_ Stage 2 are cut, thus dividing it into evaginated and alar-extension

‘portions, the following conditions are very noticeable. First, it is

clear that the evaginated portion has deepened. This is due to

64 DAVID C. HILTON

encroachment upon the lateral alar extensions as observed less con-

spicuously in the previous stage, to further extension of the ventral

wall, and to increase in the anterior and posterior constrictions.

Second, the mouth of the evagination is inclined more antero-

posteriad, and opens more dorsad into the lumen of the foregut.

Third, the alar extensions, instead of being almost posterior to the

evaginated portion as in stage 1, are dorso-posteriad (d/l). Since

there is no free border, the line for the plane to pass through must

be drawn to the most ventral point on the posterior border, instead

of the most anterior point on the free border as in the previous

stage.

The evagination has become trilobed by the anterior and the

anterior ventral depressions. Since the former one is not constantly

found in different specimens of this and older stages, the bilobing

of the anterior wall is adventitious, but the bilobed condition of the

ventral wall is a constant character of the development. In this

stage the lobulation is not apparent on the lateral surfaces.

Stage 4 (Figs. 4 and 4a). By a process of lateral fusions and

antero-posterior separations of the walls in the posterior constric-

tion between the proton and intestine, this constriction has been

deepened so greatly, that, on account of this deepening and possibly

by the orientation of the posterior portion of the ventral wall into an

approximate dorso-ventral direction, a posterior surface to the pro-

ton has been created.

The dorsal border of this new surface is on a level with the same

border of the lateral and anterior walls. Consequently, no plane

cutting the proton in accord with previously given directions will

divide it into two parts. The alar extensions of previous stages

have been incorporated completely into the evagination. Therefore,

the proton is now an evagination from the ventral surface of the

foregut into the septum transversum, and its cavity communicates

dorsally by a slightly constricted neck, with the lumen of the fore-

gut.

The variations in the contour of the proton and in its relative -

dimensions seem to become greater in these more advanced stages.

In lateral aspect and in median sagittal section, there is considerable

antithesis between the proton of embryo G under discussion and that

of embryo D (Figs. 5 and 5a). The former is very deep and the

depression between the pars hepatica and the pars cystica is slight.

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 65

the Iatter this depression is very deep, and thereby makes the

liver proton appear to be a quite double evagination. The proton

embryo G in cross-section is narrow, deep, regular, and U-shaped.

Embryo P furnishes a proton which is extremely irregular on every

eS oe SS ee ae

hepatica of embryo D would reveal a shallow evagination with a

lateral dimension exceeding the dorso-ventral measurement several

‘the reverse of the proportions found in embryo G.

The solution of the problem as to whether in embryo D there are

‘teally one or two diverticula may be approached from two stand-

_ Standpoint 1. Take dorso-ventral measurements in the median

plane from the dorsal wall of the intestine, to the ventral surface

of the intestine anterior to the proton (d'), to the same surface

‘posterior to the proton (d*), and to the surface of the depression

‘between the pars hepatica and pars cystica (d*). The last measure-

ment is no greater than the first or second, and no point elsewhere

‘on the depression is below the level of the point measured to. And

since the intestinal caliber anterior and posterior to the proton is

‘about equal, the space between the two diverticula may be consid-

‘ered to be in the level of the ventral surface of the intestine. There-

Standpoint 2. Cut the proton by a plane as directed for demon-

‘strating the evaginated portion in other models. At no point does

depression rise quite high enough to meet the plane. There-

fore, the plane may be considered to coincide with the mouth of a

single, deeply bilobed evagination.

_ The view that there are two diverticula appears to me the most

obvious and satisfactory. In assuming this attitude, the objection

to it that has been pointed out may be answered by referring to the

fact that the dorsal wall of the intestine above this depression suffers

down-curving, at least as great as the distance which the depression

lacks of meeting the plane.

‘This is the only model which has shown two distinctly separate

diverticula, and is the only one in which the intestinal wall above

_ dips downward. The contour of the intestine at this place may

have been straight normally, although not the slightest evidence was

discovered to indicate the curved condition to be abnormal. The

‘external appearance of the embryo before embedding was perfect.

;

66 DAVID C. HILTON.

The belief that there are two separate diverticula does not in the

least dispose one to the conclusion that they were so primarily.

They probably were not, because a simple exaggeration of the ante-

rior ventral depression could have been the factor which made two

separate diverticula out of a single primary one, in the manner

similar to that by which the bilobing of other protons has been

effected.

The rudiment of the gall-bladder which in the previous stage

is very shallow and basin-like, and opens dorsad within the primary

evagination of the proton, is, in the present stage, a somewhat deeper

evagination of the ventral part of the posterior wall, and opens

anteriad (gb).

In the posterior wall, between the gall-bladder and the intestine

above, is a more or less conical, bilobed, solid outgrowth of tissue.

This is the ventral pancreas (pv). It is a thickening of that portion

of the pars cystica which goes to form the ductus choledochus.

Only one stage later than that just reviewed has been modelled

(Fig. 6). In it the zone of constriction has closed in so as to

leave a very small, narrow neck at the mouth of evagination ().

The evagination is somewhat flask-shaped and deeply divided into

four lobes, aside from that portion composing the rudiment of the

ventral pancreas. One of these lobes extending posteriad and to the

right is the gall-bladder. It is well rounded; its wall being thicker

on an average than that of the pars hepatica. Its surface is smooth

and sharply defined from the adjacent tissue of the prehepaticus. Of

the other three, one is to the right (rt), one is to the left (/), in-

clining dorsad, and one proceeds ventrad (v). The left one is the

smallest. They taper toward their distal end and, at their proximal

extremity, spread out into the walls of the main cavity of the flask.

Where the proton joins the intestine, the latter runs somewhat trans-

versely from left to right (ifr).

Relation of morphologic variations to blood sinuses

Idiosyncrasies in mural contour are accompanied by correspond-

ing peculiarities in the disposition of adjacent sinuses.

In embryo D (Fig. 16) there is a large vessel lying imme-

diately beneath the deep depression between the pars hepatica and

pars cystica. On both sides of the deep, narrow, U-shaped wall of

embryo G (Fig. 14) are observed very large sinus-like spaces.

‘ie

— = ~~

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 67

T Mile Gate Eppcare to have dipped ventrad in the narrow interval

between the vessels.

In embryos X', J, and K (Figs. 11, 12, and 13), the sinus

venosus at its posterior end lies close to the anterior wall of the

proton, in such a way that it coincides with the anterior (sinus)

ession (ds) which bilobes the anterior surface. This depression

‘seen in the models of embryos J and K. Thus, the bilobing of

€ anterior surface seems to be due to the close approximation of

ee oe Ocye Preset, of 8 Sen ee ee

In the very irregular wall of embryo P (Fig. 15), the deep

are filled, more or less, with large sinuses. From these

_ Observations it appears that the irregularities of growth are the

results of obstructions to expansion, offered here and there by these

sinuses.

at General configuration of the external surface

__ In stage 1 (Embryo X*) and in stage 2 (Embryos S and J), the

surface, although sinuous by virtue of indentations and convolu-

___ tions, is smooth, and well defined from the adjacent tissue of the

_ septum transversum. The few exceptions to this are some minute

papillary excrescences. They protrude slightly from the general

surface. In stage 1 they are less in number and in magnitude than

im the later stages (Fig. 15, p).

_ The papillae develop earliest and are largest on the anterior median

tase. Posteriad over the lateral and ventral surface, they become

smaller and fewer and finally disappear. In other words, the older

__ the protonic wall, the more mature and numerous are the papillae.

__ Consequently, the more advanced the stage of development, the more

_ completely and extensively is the posterior and younger region of the

_ proton involved in the extrusion of papillae.

____ Im stage 3, where for the first time there is a definite pars cystica,

it is necessary to state that this part of the proton always possesses

eye smooth, well-defined wall, excepting perhaps at its most anterior

portion. The pars hepatica, however, especially anteriorly, is

_ studded with numerous papillae, some of which have grown out into

_ short rods. These rods are usually separated by vascular spaces.

dealers unplaaa peg abi.ges Gua

Ep aaterior region of the proton, where they are more mature, are not

ee sre cloeely spproxinnted, forming a more or less com-

68 DAVID C. HILTON

pact cell mass (Figs. 13 and 19, rc). This is the only structure

apparently homologous to the “kompakte Leberanlage.” It is

minutely discussed under histogenesis.

In stage 4 (Embryos G and D), the papillae and rods have still

further increased in number, magnitude, and range. Most of the

simple short rods of stage 3 have elongated and branched. These

branches, in most places, have united end to end, and form a net-

work (Figs. 14 and 16). This configuration of the wall occupies

at least the anterior half of the proton. It becomes less complex

posteriorly and the rod disappears altogether at a limit indicated

(Fig. 4, rl). Posterior to this limit the surface is smooth or

slightly papillated. But within this smooth wall, as far posterior

as the dotted line (p/), the cell arrangement peculiar to potential

evaginations is discernible. Since all this structural variation which

determines hepatic tissue, covers about four-fifths of the wall, that

amount is gland-formative and represents wholly or almost entirely

the pars hepatica portion of the proton. These potential structures

are discussed under histogenesis.

In later stages, this net-work of rods becomes larger and more

complex, and finally arranged into the characteristic glandular struc-

ture. In the case of embryo E, the rods arise from all parts of the

proton excepting from the gall-bladder, the appended ventral pan-

creas, and the narrow neck leading to the intestine.

Comparison of results with those of other authors on mammalia

His (81) says that the “ Leberanlage” first appears as a longi-

tudinal strip on the ventral side of the foregut. Peterson (99) also

demonstrated this in the pig. This research confirms it likewise.

“ Kolliker (79) hatte bei dem Kaninchen zwei Lebersprossen

beschrieben, deren erster am zehnten Tage auftritt, wahrend der

zweite erst am elften Tage der Schwangerschaft erscheint. Sie

stehen zu einander in einem ungefahren rechten Winkel.” [Quoted

from Brachet (96).]

KGlliker’s two “Lebergange” are given as right and left. Stage

3 furnishes two “ Lebersprossen” in the relation of right angle to

each other, but one is anterior and projects forward, the other is

posterior and projects downward. The anterior one is the pars

hepatica. The posterior one is the pars cystica (Fig. 3a). The

model of embryo K, which is taken as the type of stage 3, is evi-

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 69

ently trilobed instead of bilobed. However, since the anterior

~. oe s) depression, which divides the pars hepatica into two parts,

___ is adventitious, and since the anterior ventral depression, which di-

_ yides the proton into the pars hepatica and pars cystica, is a constant

43 eee Pe morvbolcey, the bilobed condition is the character-

“Felix (92) dagegen will die zwei Leberknospen, aus denen diese

- Driise hervorgehen soll, bei menschlichen Embryonen gefunden

as Indessen sind diese beiden Knospen weit davon entfernt,

zu gleichen, welche KOlliker bei dem Kaninchen gesehen hat.

er giebt an, dass der eine kranial, der andere kaudal gelegen

Der letztere endlich ist ganz und gar rudimentar und kann in

kaum wieder erkannt werden.” [Quoted from

]

e research does not bear out the results of Felix, because no

___ atrophic “ Leberknospe” is present. On the other hand, both the

“His. (81) hatte die zwei von Kdlliker beschriebenen Divertikel

4 weder beim Kaninchen, noch beim Menschen wiedergefunden.

A Stets sah er jedoch nur einen einzigen, der von der ventralen Wand

4 des Darmrohres ausging und der zum grossen Teil mit dem Septum

a transversum zusammenhing; durch Zellwucherung seiner Wande

-entstand aus ihm eine dichte, kompakte Zellmasse die kompakte

g “Die Gallenblase tritt spiter auf in Gestalt eines sekundiren Di-

a vertikels des Leberausfiihrungsganges.” [Quoted from Brachet

. MS NiaGiink G8 cheap" te tote” pittetve’ than ‘this, because no

_ diverticulum appears in the former. Otherwise the proton of stage

__ fT answers in a gencral way to this description. The evaginated por-

__ tion of the proton in stages 2 and 3, and the entire proton of stage

g 4, correspond more or less to His’ description. Although the gall-

_ bladder appears subsequent to the beginning of the hepatic portion

b _of the proton, it is, nevertheless, evident in stage 3, wherein there

__ is as yet no well-defined “Ausfiihrungsgang.” Moreover, in stage

"4 and in the latest stage modelled, the gall-bladder is below the

_ “Ausfiihrungsgang.” Concerning the “kompakte Leberanlage”

_ 0f His, which is confirmed by Brachet and by Hammar, a discussion

pH found under histogenesia

7° DAVID C, HILTON

Hammar (97) after stating the proton in some other classes of

vertebrata to be a fold of the ventral gut wall, turns to mammalia

and describes it in the rabbit, in the following quotations:

“Auch bei den Saugetieren wird eine stufenahnliche, sich zwischen

die Venenschenkel des Herzens hervorschiebende Leberfalte beim

Darmverschlusse gebildet (Fig. 4).”

This statement indicates that the proton in the pig and rabbit does

not differ materially in position and derivation.

“Wahrend diese letztere sich zum trabecularen Leberparenchym

herausbildet, wird die Leberfalte allmahlich durch eine caudalwarts

fortschreitende Abschniirung (Fig. 5) als ein selbstandiger Gang

vom Darmrohre abgetrennt.”

In connection with this last quotation, it should be noted that he

observes the anterior constriction, proceeding “caudalwarts,” to be

the only factor potent in the separation of the proton from the intes-

tine. And, according to his model (Fig. 5), this seems to be true,

since no posterior counterpart to it, such as the posterior constriction

in the proton of the pig, is appreciable. The fact that the anterior

constriction between the proton and intestine is slight in the pig, and

that in the rabbit it extends posteriad as far as the posterior border

of the ventral surface, makes a vast difference in the appearance of

the two protons. In the rabbit the proton, as presented by Ham-

mar’s Fig. 4 and Fig. 5, is entirely a deep evagination projecting

anteriad. At its posterior aspect alone it opens into the foregut

where that receives the yolk-stalk. The shallow proton of the pig

embryo in those stages corresponding to the aforementioned figures

of Hammar, presents both posterior and dorsal aspects open, and it

is an evagination only in part.

If in stage 3 (Fig. 3) the anterior constriction was deepened

antero-posteriorly, until it furnished a dorsal surface about equal in

length to the ventral surface of the proton, it would give an evagina-

tion projecting anteriad beneath the intestine and opening into it

posteriorly. The dotted line (ha) indicates the imagined constric-

tion. Such a condition is what Hammar gives for the rabbit in his

Fig. 4 and Fig. 5.

“Unmittelbar caudalwarts von der compacten Leberanlage sprosst

ein anfangs ganz kurzer Zapfen von der ventralen Wand dieses

Ganges hervor (Fig. 6).”

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 7?

__ Hammar’s model illustrated by his Fig. 6, the gall-bladder rudi-

ment of which he describes in the above quotation (“ein anfangs

_ ganz kurzer Zapfen”), resembles very closely the model of the

dorsad instead of caudad as in Fig. 5. In other words, the mouth

_ of the evagination has been shifted and a posterior wall created,

__wndoubtedly by the initiation and deepening of the posterior con-

_ Striction. These phenomena transpired in the proton of the pig

_ during stage 3, and resulted in the form-condition of stage 4. The

‘metamorphosis in both instances is similar, and it is not unlikely that

_ the factors producing it in both are the same.

Brachet (96) :

“ Auch bei dem Kaninchen wird die Leber durch eine breite longi-

_tudinale Ausbuchtung (renflement) der ventralen Darmwand ange-

legt, welche sich iiber diese vom Sinus venosus bis zum Nabel

hhinzieht. In den vorderen und mittleren Partien dieser Ausbuch-

tung, oder dieser Vorstiilpung der ventralen Darmseite fangt das

Epithel zu wachsen an, bildet einen epithelialen Zellhaufen, welcher

in Verbindung mit dem Septum transversum tritt und zur ‘kompak-

ten Leberanlage’ von His wird.”

The above elucidation of the derivation and relation of the proton

e to the septum transversum answers to the condition found in the pig.

As to the posterior boundary, it answers to the two early stages, but

not to later ones, because in them the ordinary intestine intervenes

| _ between the proton and the “abel.” As to shape, stage 1 in the

o .. pig proton is more primitive, since as yet there is no “ Ausbuchtung ”

or “Vorstiilpung.” Concerning the “epithelialen Zellhaufen,” a

3 _ discussion is made under histogenesis, where the “kompakte Leber-

_ anlage” is taken up.

_ “An dem hintersten oder kaudalsten Teile der Wand jener Aus-

_ buchtung (renflement) findet niemals eine derartige Zellwucherung

__ statt. Er bleibt immer glatt und wohl von seiner Umgebung abge-

a grenzt. Durch Abschniirung und Eingenwachstum bildet sich spiter

a _ die Gallenblase daraus.”

72 DAVID C. HILTON

“In der That kann man also auch hier bei der primitiven Leber-

anlage eine ‘Pars hepatica’ und eine ‘Pars cystica’ unterscheiden. . .”

“Eine doppelte Abschniirung, die in kranio-kaudaler wie in kaudo-

kranialer Richtung erfolgt, trennt sowohl die ‘ Pars hepatica’ wie

die ‘ Pars cystica’ von der ventralen Wand des Darmrohres und

lasst sie nur noch durch einen breiten Stiel damit verbunden der

dann seinerseits spater zum Ductus choledochus wird.”

All points considered in the three paragraphs just quoted are true

for the proton of the pig.

No author speaks of that portion of the proton which, in certain

stages, extends beyond the evaginated portion, and which is desig-

nated in this paper as the lateral alar extension.

Notes on the origin of the ventral pancreas

The ventral pancreas is located on the posterior portion of the

pars cystica. In case the gall-bladder portion of the pars cystica

has been differentiated from the ductus-choledochus portion, the

ventral pancreas appears on the latter, thus being situated between

the gall-bladder and the intestine.

There are three form-conditions of the ventral pancreas illustrated

in the plates. The most primitive is that in the model of embryo

D (Fig. 5). Herein it is in the shape of two elongated solid out-

growths projecting caudad and slightly ventrad from the posterior

lateral aspect of the pars cystica, considerably to the right of the

median line (pv). One is several times smaller than the other and

situated antero-ventrad to it. The latter is club-shaped and about

three to four times longer than the smaller one.

The second morphologic feature of interest is observed in the

model of embryo G (Fig. 4). Both embryo D and embryo G

belong to stage 4 in the development of the hepatic proton, but

embryo G is decidedly the more mature as respects the liver proton

and probably also as regards the ventral pancreas. It subsists in a

solid, single, and somewhat conical extrusion of cells placed in the

median line, dorsal to the gall-bladder and ventral to the intestine. —

Although the ventral pancreas in this case is single, it is not simple,

because a laterally bilobed condition is present. Moreover, these two

lobes stand in the same relation that obtains between the two sepa-

rate projections of embryo D; that is, the right lobe arises more

‘The most mature form of the ventral pancreas, furnished by em-

bryo E, the oldest one studied, is that of a long narrow solid out-

median line by shifting posteriad, pasha a eae arta

__ by approximation. Furthermore, this fused pancreatic proton has

__ imereased in length posteriad and dorsad toward the right aspect of

the intestine. Wlassow (95) discovered in the pig merely a single

HISTOGENESIS

ayy The simple, smooth wall

Im stages 1 and 2, as above defined, the external surface of

_ the protonic wall is nearly smooth. This smooth wall includes a

_ Varying portion of the proton in all stages described in this paper.

__ Its histological structure provides the basis for the more highly spe-

| In stage 1, the intestinal epithelium is composed of a single layer

Of short columnar cells. Where the intestine becomes continuous

with the hepatic proton, an immediate alteration in the cell-arrange-

ment and in the thickness of the wall is evident.

____ Not only has the wall of the proton differentiated from the intes-

tinal wall in (1) cell-arrangement, and in (2) thickness, but also

__ plasmatic portion of the liver cells than to any other tissue contigu-

ous. Nuclear stains also take avidiously. When surrounding tis-

Sues are well stained, the liver is liable to be over-stained. Stages

__ ft and 2 do not exhibit this peculiarity in plasma-staining as much

____ a8 those more advanced, nor does the posterior portion of the proton

74 DAVID C. HILTON

indicate it so markedly as the anterior, because the more differen-

tiated the tissue is, the deeper it stains. The pars cystica shows it

little, if any.

Stage 1 (Fig. 7). The free yolk-stalk border of the proton

is composed of a single layer of cuboidal or polyhedral cells (cc).

Next to the margin of cuboidal cells is a region of short columnar

or wedge-shaped cells (csw). Then, more distal from the free bor-

der where mural thickness increases, they are longer and more closely

packed. Where the wall gains its average diameter, they are slender

wedge-shaped cells, generally spanning from surface to surface

(clw).

At intervals, polyhedral cells with spherical nuclei are found

adjacent to the inner surface. They are often observed in process

of mitosis. In fact, most of the karyokinesis in the proton is near

this surface and in these cells (cm).

The nuclei of the marginal cuboidal cells are generally spherical ;

of the columnar and wedge-shaped cells the nuclei are generally

oblong or ovate; and the longer the cells, the longer their nuclei

are.

Since so many of the long cells, even in the thickest part of the

wall, span its entire width, one can hardly demonstrate that more

than a single cell-layer exists in the proton wall. But wherever the

wall is composed of columnar or wedge-shaped cells, there are at

least two regions corresponding to the mural surfaces and character-

ized by peculiar cell-structure and arrangement. The regions are

(1) the inner, where the inner extremities of the long wedge-shaped

cells and the polyhedral cells with spherical nuclei are found; and

(2) the outer, made up of the outer, nucleated extremities of the

long wedge-shaped cells. Of these regions, the former occupies

about one-fourth the diameter of the protonic wall, and karyokenesis

is more common in it than in the latter, which constitutes the remain-

ing three-fourths of the diameter.

The nuclei of the long cells are in three more or less definite series

or rows, where the wall is of ordinary thickness, and in two rows -

in the tapering portion of the wall composed of short, wedge-shaped

cells. As regards the three rows of nuclei in the former region,

those of the inner row are approximately ovate. Their narrower

end points outward and is often located between the inner extremi-

ties of two nuclei of the middle row (Figs. 7, 8, and 17, ni).

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 75

The nuclei of the outer region are of similar shape. Their inner

_ extremity is the narrower and lies between the outer ends of nuclei

of the middle region (no). The nuclei of the middle region are

oval or ovate, tapering at either or both ends. Thus the nuclei of

the long cells are observed to dove-tail with each other. As regards

; * the two rows of nuclei in the latter region of the wall, they are more

= rotund and dove-tail with one another near the middle of the mural

IEE Ribs sad aivingement, edd WANE oF Oral nucked ate

evident everywhere, especially in the inner and outer series.

_ Stage 2 (Figs. 8 and 17). The principal differences in the

histology of stage 2 and of stage 1 are observed in (1) a much more

tapid transition from the thin yolk-stalk border to the normal thick-

ness, and in (2) the greater thickness of the wall, involving an in-

crease in the length and number of cells and nuclei.

_ Stages 3 and 4. The histology of the wall in these subsequent

Stages varies only in minor details from that in stage 2. Of course,

the tapering yolk-stalk border is absent. The mural thickness may

or may not be greater. If it is considerable, there may be more

3 than three rows of nuclei evident. The typical arrangement is less

_--—s conspicuous because of the increasing multiplicity of secondary

___ changes incident to the developing glandular structures.

Development of the glandular structure

_ Potential evagination. The incipiency of gland development is

very evident, even in stage 1. It is indicated by a peculiarity of

arrangement among the nuclei of the long wedge-shaped cells. At

the indicated place on the figure (Fig. 7, ep), six nuclei form a

little arch, its base resting on the inner surface and its vault reach-

ing to the outer surface of the wall. The cup-shaped cavity of the

arch is filled with the cytoplasmic inner extremities of the cells pos-

sessing the nuclei which compose it. These cells and their nuclei are

perpendicular to the surfaces. The cells themselves are not peculiar,

excepting as regards the collective arrangement of their nuclei.

Furthermore, this structure is entirely within the wall at its ordinary

thickness. Nothing can be observed of it superficially. It is a

potential evagination. Probably even a much earlier condition of

this is found among the layer of short, columnar cells, in the taper-

76 DAVID C. HILTON

ing yolk-stalk portion of the wall (Fig. 7, op). Here four or five

spheroidal and oval nuclei form a very low arch.

It seems that the conditions for the development of the cotetial

evagination are found in (1) the chaotic distribution of nuclei in

the thin margin of the wall, two contiguous nuclei seldom being at

exactly the same level ; (2) in the variable size of nuclei; and (3) in

the difference of their surface contour. With these three conditions

present, it is easy to see that where the cells and nuclei begin to

crowd each other closely, as at (ep), not only do the cells elongate,

but also the nuclei arrange themselves serially. The serial accom-

modation is probably accomplished by the nuclei moving toward the

inner or the outer surface, wherever pressure directs them. The

formation of arches is one of the possible and apparent results of

pressure on the nuclei so conditioned.

But these factors do not explain why the arches always take the

form of evaginations, and seem never to construct invaginations.

Perhaps another factor is physiological, in that the source of nutri-

ment is from the outer surface where the blood-spaces of the septum

transversum bathe the proton with nutrient fluid (Figs. 14 and 15,

sn). That this conjecture may be of importance is supported by

the fact that, in general, nuclei are in that part of the cell wherein

physiological activity is greatest, and by the fact that the nuclei in

the proton tend to be and are in large part near the outer extremity

of their cells. The mechanical conditions of pressure on each side

of the wall undoubtedly differ. On the lumen surface there is sim-

ply free fluid which presumably exerts an equal hydrostatic pressure

at all points. On the other side there is not only fluid pressure, but

also a framework of fixed tissue which furnishes some support at

numerous points and at other places provides very little resisting

power to counter pressure. Yet it seems that other factors are in-

volved, because the pars cystica, developing under apparently similar

conditions, does not form glandular structures.

The more advanced potential evaginations, such as stage 2 fur-

nishes, are deeper, and more cells take part in their make-up (Figs.

8 and 17, ep). The cells of every advanced evagination, with

the exception of those in the central axis of each, do not extend

perpendicularly to the mural surfaces, but are disposed obliquely

to them. They are oblique to the central axis, so that their outer

ends are more distal to it than are their inner ends which are directed

| MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 77

toward it, and aid in filling with cytoplasm the cup-shaped cavity

of the arch. The more mature the potential evaginations are, the

_ more pronounced as a rule, is this obliquity of the peripheral cells

:. om emery Where the axis of the evagination meets the inner

a Seeeeee Of the proton, emall, sharply-defined indentations sometimes

= SPapile-formation. Papillae, varying in form, project from the

external surface of the pars hepatica, and perhaps also from con-

_ tiguous areas of the pars cystica. Even in stage 1 a few very low

rudimentary papillae are noticeable. These papillae are simply a

higher development of the glandular structure. What have been

Observed to be potential evaginations are the prototypes of exuberant

evaginations, the papillae. That is, the papillae or exuberant evag-

inations are the second morphologic aspect of the gland-formative

‘process. Histologically, three modifications of the papillae are easily

recognizable. Each represents a certain degree of maturity.

The least mature papillae (Fig. 7, p) differ from the potential

a _ €vaginations only by virtue of their columnar or wedge-shaped cells

being longer than the longest cells of the wall at its ordinary thick-

ness. They exceed them in length by the extent that the papillae

‘The more mature papillae possess longer cells composing the core

a | about their central axis. Often some of the cells are spatulate ; their

___ long, slender inner extremities reaching across the wall to its inner

a _ surface (Fig. 9, p?), converge more uniformly and sharply toward

_ the central axis than in younger papillae. The most peripheral cells

are long, wedge-shaped, or slightly spatulate. To reach the outer

surface, they bend obliquely away from the central axis at that ex-

tremity, and are no longer straight (Fig. 9, p?, c/w).

The most mature papillae are longer than others (Fig. 18).

_ The cells of the axial core are extremely long and spatulate. They

are approximately straight and parallel with the papillary axis.

Their long, slender inner ends often taper apparently to hair-like

processes, and it is doubtful if those most centrally situated reach

as far as the inner surface. In most sections some of them do not

appear to. The change of cellular outline from wedge-shaped to

spatulate has invaded the peripheral portion of the papillae from the

axial core outward, and all cells, with perhaps the exception of a

few most peripheral, are spatulate. The expanded outer extremi-

78 DAVID C, HILTON

ties of the peripheral cells bend to a much greater degree than in

the less mature papillae, and may be almost at right angles to their

slender inner ends. There is a tendency for this bend to be suffi-

cient for the cells to meet the curving papilla-surface at right angles.

The shape of the nucleus does not change appreciably when a

cell develops from the wedge-shaped to the spatulate form. But in

the expanded outer end of the spatulate cells which form the apices

of the most mature papillae, the nuclei are somewhat spherical. All

cells which, in later stages of normal development, are superposed

on these apical spatulate cells, are polyhedral and possess spherical

nuclei. Such polyhedral cells with spherical nuclei, are characteris-

tic of the rods constituting the subsequent glandular structure of

the liver. Their presence marks the end of the papilla form of

evagination and the beginning of the rod-formation (Fig. 18).

Perhaps the first few polyhedral cells are modified spatulate cells

which have assumed this shape by a progressive shortening of their

attenuated extremities. .

Rod-formation. The ordinary growth of the rods, so far as

traced, is characterized by cell-proliferation, and by the arrange-

ment of these cells according to a certain type; by the extension of

the rods into the septum transversum; by their branching; and by

the resolution of these branches into a network of rods.

The size of the rods at their base depends very largely on the

size of their antecedent potential evaginations and papillae. If a

rod springs from a very wide papilla (Fig. 15, pw), the rod is

broad. A cross-section of such a one shows a circloid area com-

posed of twenty or more polyhedral, cuboidal, or short columnar

cells, arranged in a single row about a common center. At the

center a small lumen is often apparent. The nuclei of the polyhedral

cells are spherical; of the columnar cells, slightly oval. They al-

ways tend to be distributed at the peripheral side of the cells. Ifa

rod springs from a very slender papilla (Fig. 15, ps), it is cor-

respondingly slender and has much the same structure in section

that the broad rod exhibits.

Obstruction to growth modifies the form of the rods and of their

cells. When a simple rod grows into the septum transversum be-

tween blood-vessels, where there is room for its unthwarted exten-

sion, it develops typically a straight cylinder with rounded distal

extremity (Fig. 15, r). When its distal end rests against a

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 79

bood-reseel (Fig. 15, r), or between vessels offering obstruction

_ to extension, this extremity is apt to be excessively thick, and the

cells composing it are usually columnar instead of polyhedral. The

it median section of a rod obstructed on one side by a

vascular space is constituted on that side of well-developed columnar

cells, whereas the opposite side, which suffers less obstruction, is

‘composed of nearly cuboidal or polyhedral cells (Fig. 20).

After the simple rods have grown outward a short distance, they

en These branches also subdivide. By progressive exten-

they Some: are merely strings of single cells placed side by

_ side (Fig. 16, r’). Thus, branches may contain in a cross-section

_ from a single cell to twenty or more. Most branches show from

to eight cells (Fig. 16, rs), about a very small central lumen.

__ of the protonic wall, in some instances (Fig. 20). The trunks

Among the columnar cells of the large rods are often found poten-

tial evaginations and papilla-formations (Fig. 16, re). These

a incident to rod-outgrowths are common in certain parts

Of rods that have thickened by virtue of obstruction to extension.

‘The dendritic arrangement is never isolated and perfect. Before

_ many bifurcations have occurred, the rods fuse end to end with

____ those of the same and of contiguous systems, forming a net-work.

___ Im stage 4 the net-work is the most conspicuous portion of the devel-

oping liver (Fig. 14).

Relation of vascular spaces to glandular development.—The pro-

tonic wall is almost always separated from the blood-spaces by an

interval filled with mesenchyme. Sometimes a vessel touches the

_ proton, but never does one penetrate the wall in any degree (Figs.

45, 19, and 20). The papillae and simple original rods sustain

a similar relation to the sinuses (Figs. 14 and 16).

When the network of rods is formed, its meshes enclose a net-

_ work of blood-spaces, of which the larger near the protonic wall

_ €ome in close contact with the rods at many points (Fig. 14, sm).

: In the peripheral parts of the septum transversum the spaces are

S80 DAVID C. HILTON

small, capillary-like, and more numerous. Between them the sepa-

rate distal branches of the rods lie. Here also the vessels and rods.

are separated by mesenchyme (Fig. 14, sm). As the develop-

ment of the glandular net-work progresses, the vascular spaces near

the proton seem to increase in caliber and come into closer relation

with the rods (Fig. 14, sn).

The bifurcation of a rod seems always to be conditioned by the

close proximity of a vascular space to its distal end (Figs. 14 and 16,

bf). The two branches generally extend beyond the vascular space

in V shape. Division generally occurs before the rod is in direct

contact with the vascular space. When division occurs in proximity

to a large vascular space such as the sinus venosus, the two result-

ing branches spread out at approximately right angles to the parent-

stem.

Other authors on histogenesis, and comparisons

The most interesting deviation of the results of this research from

those of other authors on mammalia devolves about the relationship

of the vascular system in the septum transversum to the trabecula-

tion of the glandular structures derived from the primitive protonic

wall. A second important difference rests in the phenomena de-

scribed concerning the method and direct results of the gland-forma-

tive proliferation. As to the method of the gland-formative prolif-

eration, no details concerning the collective variations of form and

arrangement peculiar to cells and their nuclei in the potential evag-

inations and in the papillae, have been described.

In regard to the direct result of proliferation from the proton, His

describes the formation of a “kompakte Leberanlage” which is

later formed into a net-work. Brachet confirms this statement by

the terms “epithelialen Zellhaufen” and “kompakte Masse der

Leberzellen” (vide extracts under “ Morphogenesis”). Hammar

also gives expression to the same idea.

But no “kompakte Leberanlage” has been evident in the em-

bryonic pig liver as here described. The rods of cells are morpho- .

logically distinct from their incipiency and, as a rule, remain sepa-

rate. If a “kompakte Leberanlage” is evident on the wall of the

proton, it is due to secondary fusion.

The relationship of the vascular system to the trabeculation of the

gland-formative cells, as expressed by Shore (91) and by Brachet

MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 8

(96), is that blood-vessels penetrate the “kompakte Leberanlage”

___ and break it up into a net-work of rods. The following quotation

a from Brachet (96) illustrates the point in question :

___ “In der grossen Mehrzahl der Fille entwickelt sich diese Netz

| - barschaft und zwar hauptsichlich den Venae omphalo-mesentericae

_ entspringen, in the kompakte Masse der Leberzellen, die durch

_ Proliferation aus der primitiven Leberanlage entstanden ist.”

According to the results of this research, however, the net-work

of rods in the embryonic pig is formed independently of the active

___ imtervention of vascular spaces. The rods springing from the pro-

contact of vascular spaces. Many times they grow out where there

are no vascular spaces anywhere near. The rods extend between

the vascular spaces already present in the septum, and thus are kept

_ Separate from one another. Their individuality is retained typically,

ss except when some of their advancing extremities meet and fuse.

The entrance of vascular spaces into the hepatic tissue plays no

active part in trabeculation of the gland, because they never pene-

trate into the proton or into the individual rods derived therefrom.

Furthermore, the organization of the glandular elements is seen

within the original wall, before any external manifestations of them

are visible.

Ee. The vascular spaces limit and determine the possible direction of

fod growth. They are also passively concerned in making the net-

_ work, in that they facilitate subdivision by offering obstruction at

the free ends of rods, thus making it convenient for them to branch

in order to extend themselves.

In short, the hepatic tissue, instead of being grown into by the

vessels, grows out and extends among and around them, although

by virtue of increases in caliber, the vascular spaces actively change

the location of rods.

Fusion of rods: Collateral growth: Disorganization

The importance of the vascular spaces in keeping the rods sepa-

rate is very obvious when it is noted how prone they are to fuse into

@ more or less homogeneous mass, where they run together in avas-

cular areas (Fig. 14, rc).

82 DAVID C. HILTON

That which, to some extent, resembles the “kompakte Leberan-

lage” of His is found in some embryos. It is best demonstrated in

about stage 3 on the anterior wall of the proton, immediately pos-

terior to the sinus venosus (Fig. 19). It is produced by the col-

lateral outgrowth of a number of closely approximated rods into

an almost avascular space. Since the region is practically avascular,

and the rods contiguous, there arises a mass of tissue which produces

a considerable thickening of the wall. But it is by no means a

heterogeneous mass. It is a collection of contiguous rods. Their

close approximation encourages fusion and more or less disorganiza-

tion. In the figure cited, vascular spaces are apparently penetrating

this collection. They are always between individuals of the collec-

tion. Therefore, they do not convert the outgrowth into rods, since

the latter are already complete organizations, as can be observed by

tracing each to its fundamental, histological arrangement within the

protonic wall. The vessels simply separate the individuals from each

other. Some of the evagination-formations at the bases of the rods

are not illustrated as clearly in the figure given as in adjoining sec-

tions of the series.

Problems in trabeculation

There are some especially intricate problems in regard to the rela-

tion of the vascular system to the hepatic structures. Some of these

problems could not be explained by direct demonstration. For in-

stance, when a vessel is entirely surrounded by hepatic tissue it is

often impossible to get a clew that will determine whether the vessel

has grown into the hepatic structure, or has been surrounded by it.

But, in certain cases, at a little distance from the circumference of

the vessel, the site of the bifurcation of a rod has been seen; the two

branches of the rod constituting the tissue which envelops the vessel.

A very interesting example of a similar condition is conspicuous in

cases (Fig. 10, sn), wherein a vessel at the outer border of the

protonic wall is completely enveloped in a dense mass of hepatic

tissue. That this vessel lies between two rods which were originally

separated is demonstrated by the fact that in the wall on either side

of the vessel are found the characteristic evagination-structures from

which rods have sprung. The evagination to the right of the vessel

discussed is not very evident in the figure, but is plain in an adjoin-

ing section of the series.

_ MORPHOGENESIS AND HISTOGENESIS OF THE LIVER 83

‘ hy itesever 2 rod becomes surrounded by a vascular space, it is

3 impossible to decide whether the rod has pushed its way in, or

whether the vascular space has expanded down over the end and

_ sides of it (Fig. 15, 7).

__ Im case a vessel appears within a disorganized mass of rods, it is

impossible to demonstrate what relation it has sustained

Absence of the vaso-formative cells of Van der Stricht

Two forms of cells are described in the embryonic liver by Toldt

and Zuckerkand! (75), and by Van der Stricht. One kind is the

my cell with granular protoplasm. The other kind is a

round cell with clear cytoplasm. The following quotation from

Brachet (96) describes the two forms of which the round, clear type

__ is said to be vaso-formative and the source of an intra-trabecular

network of blood-vessels.

Was nun den histologischen Aufbau der Lebertrabekel anlangt,

80 bestehen sie nach Toldt und Zuckerkandl aus zwei Zellarten. Die

einen sind die eigentlichen Leberzellen von kubischer oder polyé-

____ drischer Gestalt, mit granuliertem Protoplasma und grossem Kerne ;

___ die anderen sind klein, rund und besitzen kein gekérntes Protoplasma.

_ __-“Toldt und Zuckerkand! hatten diese letztere Zellform hauptsach-

_ lich im vierten Monat ausserordentlich reichlich angetroffen. . . .

i) "Van der Stricht tnd Kostanecki haben jedoch geltend gemacht,

| = dass die runden, hellen Zellen Toldts und Zuckerkandls nichts an-

_ ders als Erythroblasten sind, welche die Maschen des intratrabeku-

laren Gefassnetzes behaupten.”

_____ It was impossible to find any small, round, clear cells in the stages

of development which were studied, with the exception of erythro-

_ blasts in the sinuses and capillaries.

a The gall-bladder wall

___ The gall-bladder wall in the stages discussed partakes of a his-

_ tological arrangement similar to that described under the simple

_ smooth wall. It is relatively thicker than that portion of the proton

; SEETE @° pers hepeticn, end the columnar celle are therefore

84 DAVID C, HILTON

List or Empryos crtep in THe Text

Embryo Protovertebrae Embryo s Chart Age

x 19 8 17 days.

S 21 9 16% *

J 21-22 10 16-17 *

P 26-27 10-11 16% “

K 27-(28) 11 16% “

F 28 11-12 164% “

D 30-31 12 7% “

G 32 12 17% “

E 37 14 20

BIBLIOGRAPHY

Bracuert, A. ;

96. Die Entwickelung und Histogenese der Leber und des Pankreas.

Anatomische Hefte, Bd. VI.

Braus, HERMAN.

96. Untersuchungen zur vergieichenden Histologie der Leber der Wirbel-

thiere. Habilitationsschrift mediz. Fakult. Jena.

Brun, A. von.

94. Leber und deren Entwickelung. Anatomische Hefte, Bd. IV.

Foster AND BALFour.

93. Elements of Embryology.

Fevrx, WALTER.

92. Zur Leber und Pankreas-Entwickelung. Arch. fir Anat. u. Entwick.

Hamoakg, J. Aue.

97. Ueber einige Hauptziige der ersten embryonalen Leberentwickelung.

Anat. Anzeiger, Bd. XIII.

98. Zur Kenntniss der Leberentwicklung bei Amphioxus. Anatomischer

Anzeiger, Bd. XIV.

Hetster, J. C.

99. Elements of Human Embryology.

His, WILLIAM.

81. Zur Embryologie der Saiigetiere. His’ Archiv. (Quoted from C. S.

Minot’s Human Embryology.)

Kerset, F.

97. Normentafeln zur Entwickelungsgeschichte der Wirbelthiere, L

KosTANECKI.

92, Die embryonale Leber in ihrer Beziehung zur Blutbildung. Ana-

tomische Hefte, Bd. 1. (Consulted in Brachet’s Resume, ‘96.)

KOuurxer, A.

79. Entwickelungsgeschichte des Menschen und der héheren Tiere.

Zweite Auflage. (Consulted in Brachet’s Resume, 96.)

ee ee Proc. Bost. Soc. Nat.

Vol. XXVIII, No, 10

ion the Origin of the Liver. Jour. of Anat. and Physiol

‘dia Feim wed Textervesindarenan dex meeneditichen Leber

wahrend des Wachstums. Sitzungsber, d. Kaiserl. Akad. d. Wissensch.

‘Wien, ree ts Badncs Ree we

iabiahateng des Postheves bsln Scivwsia. Morpholog. Arbeiten,

von Schwalbe, Bd. IV.

details were determined by a Zeiss microscope.

DAVID C. HILTON

EXPLANATION OF PLATES

All drawings of sections were made with a camera lucida. The finest

ABBREVIATIONS

Dorsal border. n

Bifurcation. ni

Posterior border. nm

Yolk-stalk border. no

Anterior constriction. pis

Cuboidal cells. bd

Mitosis-cells. ph

Long wedge-shaped cells. P hep

Short wedge-shaped cells. P cy

Posterior constriction. pl

Diameters. ps

Lateral dimensions.

Dorso-ventral dimensions.

Anterior (sinus) depression.

Anterior ventral depression.

Posterior ventral depression.

Evagination-limit.

Alar extension.

Potential evagination.

Gall-bladder.

Dotted line indicated in rabbit.

Heart.

Intestine.

Division-line.

Neck of proton.

Nucleus of inner region.

Nucleus of middle region.

Nucleus of outer region.

Papilla.

Dorsal pancreas.

Prehepaticus.

Pars hepatica.

Pars cystica.

Papilla limit.

Slender papilla.

Wide papilla.

Ventral pancreas.

Sinus venosus.

Sinus-network.

Ventral.

Umbilical vein.

Vitelline vein.

Yolk-stalk.

PLATE (IL

OCM ASSP Gal.

PLATE IV.

OCHKESSLA cel

Plate I

of a model of the hepatic proton and adjoining in-

Sagittal section of embryo X", through the central half of the

a, exhibiting histogenesis in stage 1. 400 X.

S, stage 2. About 50 X.

section

of the

About

section of

model

About

section of

a model

4. About 65 X.

sagittal section of the same.

7 Right anterior aspect of the model of the proton of embryo E.

teral aspect of a model of the hepatic proton and adjoining in-

mbryo D, stage 4. About 75 X.

| } Transverse section through the ventral portion of the left alar ex-

Th Figs.

g. 10. A portion of a median sagittal section of the proton of embryo K.

88 DAVID C. HILTON

Plate V

Fig. 11. Median sagittal section of embryo X", stage 1. 20 X.

Fig. 12. Median sagittal section of embryo J, stage 2. 20 X.

Fig. 13. Median sagittal section of embryo K, stage 3. 20 X.

Fig. 14. Transverse section through the protonic area of embryo G, pre-

senting stage 4. 40 X.

Fig. 15. Transverse section of embryo P through its protonic area, illus-

trating the histology and morphology in stage 3. 100 X.

Fig. 16. Sagittal section of embryo D through its proton, stage 4. 100 X.

Plate VI

Fig. 17. A section similar to Fig. 8, taken slightly more anteriorly. 400 X.

Fig. 18. A transverse section from the protonic wall of embryo P, showing

cell-arrangements in the period of transition from a papilla to an incipient

rod. 500 X.

Fig. 19. A section similar to that of Fig. 10, taken immediately caudad and

ventral to the sinus venosus. (The nearest approach to a “ Kompakte

Leberanlage.”) 400 X. ;

Fig. 20. A transverse section of a portion of the protonic wall of embryo

D, depicting a short rod, and exhibiting its relation as regards cell-

arrangement and direction of growth to the near lying vascular spaces. 600 X.

PLATE V.

aes

OCH €SFP vet

PLATE VI.

we A “si 7 me ] .

eked tens

' ps

Lyi) LO »,

ie se Oe >

OCH 4EFR ei

gee

: CULTURAL STUDIES OF A NEMATODE ASSOCIATED

| WITH PLANT DECAY

By HAVEN METCALF

WITH ONE PLATE

It is well known that various nematodes are associated with plant

disease; but aside from the gall-forming species, very few have

been described from the standpoint of the plant pathologist. In

descriptions of cases of root rot, joint rot, and “ damping off,” par-

ticularly such as are associated with fungi of the form-genus Fus-

@rium, the presence of nematodes is frequently noted. The suspicion

is often expressed that the nematode, rather than the fungus, may

Stand in a causal relation to the disease. But so far as I have been

able to ascertain, no work has been done to demonstrate conclusively

the relation of nematode to rot in any given case.

OccuRRENCE

My attention was first called to this species by Mr. J. L. Sheldon

of the department of botany of the University of Nebraska, who

noticed nematodes in great numbers in corms and young stalks of

Crocus, which were affected with a soft rot; a Fusarium and bacteria

were also present. In order to separate the fungus, poured plates

were made with asparagus juice agar. To my surprise, not only

the fungus and bacteria developed in the plate, but also, after about

ten days, the nematodes, When first noticed, only three individuals

were seen, but these multiplied until in about thirty days from the

time of pouring the plate, the agar was fairly alive with nematodes,

of all degrees of development. Trial inoculations of fresh tubes and

plates showed that the nematodes could be grown readily by cer-

tain culture methods.

The same nematode was later isolated from cuttings of Petunia,

Coleus, and Geranium which “ damped off” in the green-house. In

each case Fusarium was also found. In a number of sugar beets

rotting with a characteristic bacterial rot nematodes were found

go HAVEN METCALF

(Hedgecock and Metcalf, 1903); also in the late stages of the rot

of potatoes caused by Stysanus stemonitis (Bessey, 1902). These

potatoes were on sale in the markets of Lincoln, Nebraska, and were

said to have been raised in Minnesota. The sugar beets were from

Ames, Normal, and Grand Island, Nebraska. The bulbs and cut-

tings were from the green-houses of the University of Nebraska.

Through the kindness of Mr. P. H. Rolfs, I have been able to ex-

amine certain Coleus plants from Miami, Florida, which were affected

with some sort of root gall. From these galls no fungus nor animal

parasite could be isolated, nor anything that would directly account

for the abnormal growth. But about the galls considerable numbers

of this nematode were found. Upon roots of the “iron pea” af-

fected with a characteristic, but hitherto unstudied root rot, I have

further found the same nematode in great numbers. The plants

examined were from various points in Darlington, Orangeburg, and

Oconee counties, South Carolina. The root rot in question is, in

every case that I have observed, associated with a Fusarium, and

the nematodes are always present. From these observations it

seems probable that the nematode is widely distributed.

STRUCTURE AND CLASSIFICATION

Only female forms have been observed in cultures or in decaying

plant tissue. Culture experiments show that these female forms are

sexually self-sufficient ; isolated specimens develop from the egg, and

produce eggs, which develop normally. No histological studies have

been made, hence it is impossible to say with certainty whether the

form is hermaphroditic or parthenogenetic. Observations of living

worms and those stained in toto have not revealed the presence of

spermatozoa.

The size of mature individuals is subject to considerable varia-

tion. The maximum length observed was 1.034 mm. ; but specimens

only 0.6 mm. have been observed with living larvae inside. Meas-

urements of isolated specimens show that growth in length does not

cease when egg production begins. The escape of larvae into the

body cavity, however, results in the death of the parent. Detailed

measurements of a mature individual of average size are as follows:

length, 0.87 mm. ; maximum width, 0.072 mm. ; length of oesophagus,

0.19 mm.; length from anus to posterior extremity, 0.085 mm. ;

length of eggs, 0.036 mm.; width of eggs, 0.021 mm.

CULTURE STUDIES OF A NEMATODE gr

As the measurements show, the form is rather plump. From the

SMEREE-Gward the anterior end it tapers’ gradually, but from the

cs. ona cainar shy. Cadies ins point This

_ portion is noticeably more attenuated and proportionally longer in

the Jarva than in the adult. No rings or wrinkles are perceptible

_ in the cuticula, which is perfectly transparent. The head end is

Dy Slant, with three lips, upon each of which is one very minute papilla

5 (he 3 5). The buccal cavity is rod-shaped, of equal diameter at

all points. Back of the buccal cavity the oesophagus is of nearly

| giobular bulb, which is supplied with a valvular apparatus. The in-

testinal wall is transparent in the adult, bright by transmitted light,

__ with distinct cell boundaries and nuclei. At the point of juncture

with the proctodaeum is a conspicuous cluster of large gland cells

(Fig. 4).

_ The vulva is a trifle cephalad to the middle of the body (Fig. 3).

F _ The genitalia are very variable in extent and arrangement in differ-

ent individuals; but approximately symmetrical. Sometimes the

distal ends are reflected back towards the vulva; quite as often not.

The posterior portion is most frequently reflected. Usually this does

not extend for more than half the distance from vulva to anus; while

the anterior portion usually extends to the bulb.

i” Development has not been studied, although no object could be

_ more favorable for such study. Eggs are deposited in all stages

____ Of development, or if not deposited, the larvae develop in the egg,

break out into the body cavity, where they continue to grow at the

expense of the parent; ultimately breaking through the body wall.

____ I have not been able to see that this process takes place at any par-

_ ticular period in the life of the parent. But sooner or later it seems

a to occur in every individual. Not always, however, does the escape

___ Of the larvae into the body cavity precede the death of the parent

a form; in a number of cases, the worm has died from some cause,

a and the escape of the larvae from the decaying genitalia and finally

a from the body occurred as a matter of course. Several worms con-

taining eggs I have killed by mechanical means; in every case the

a fully formed eggs have continued to develop normally. Whether

4g within or without the parent body, the larva may attain a length of

92 HAVEN METCALF

0.15 mm. before breaking out of the egg. At about this time the

larva moults (Fig. 1) ; once again at about the time egg production

While this form does not exactly correspond to any written de-

scription that I have seen, it is closely related to, if not identical

with, the form described and figured by De Man (1884) under the

name of Rhabditis brevispina Claus. The figures and measurements

given by De Man agree substantially with mine; his description dif-

fers in certain particulars. According to him, “Das Kopfende

... wird von drei, wenig hervorrugende Lippen gebildet, auf

welchen sechs sehr wenig vorstehende Papillen gefunden werden” ;

I have observed only three papillae. The vulva is located in the

middle or slightly cephalad of the middle of the body in all forms

that I have examined ; according to De Man, “ Die weibl. Geschlecht-

soffnung liegt ein wenig hinter der Mitte.” I have seen no caudal

papillae ; but according to De Man, “ Der Schwanz . . . tragt eine

laterale Papillae ungefahr in seiner Mitte.” Aside from these par-

ticulars De Man’s description of the female applies perfectly to the

form under consideration.

The original description by Claus (1862) of what he terms Anguil-

lula brevispinus, is meagre; so far as it goes, his description of the

female applies to the form which I have; and as papillae are not

mentioned, it is in agreement with De Man’s description. Regard-

ing the position of the vulva, Claus says: “ Die Geschlechts6ffnung

liegt so ziemlich in der Mitte der Liebeslange.”

Claus and De Man both describe male as well as female forms.

Biitschli (1873) describes and figures a female form which he con-

siders to be Rhabditis brevispina Claus. He says: “ Der einzige

bemerkenswerthe Unterschied, welchen ich auffand, ist, dass die

Ovarien meiner Thiere bedeutend weiter nach vorn, respective nach

hinten reichten, als dies von Claus angegeben.” But between differ-

ent individuals of the specimens which I have examined I have

found greater differences in the arrangement and extent of the

ovaries than is shown in the figures of Biitschli, Claus, and De Man.

Regarding Biitschli’s description De Man says: “ Die, von Biitschli.

. .. als brevispina beschriebene Art ist eine andere und unter-

scheidet sich besonders durch die mehr betrachtliche Ausdehnung

der Genitalien und einen verhiltnissmassig kiirzeren Schwanz.”

But a close comparison of the figures of the three authors shows

_CULTURE STUDIES OF A NEMATODE 93

the tail of the female in De Man's figure differs as much in

a depicted by Claus as that in Biitschli’s figure does in

length. Of the three figures, that of De Man most closely depicts

_ the form that I have, in this as in other respects.

a form figured by Claus exhibits distinct differentiation of

egFe

____ shown in the figures of Biitschli and De Man. In the form that I

____ have studied, there is no proper differentiation of ovary and uterus ;

____ the egg-producing and egg-retaining portions vary greatly in extent

in different individuals (see Figs. 3 and 6).

Whether the forms described by the three authors are identical,

and whether the form which I have described is identical with one

____ or all of them, must be left for some other investigator to settle.

CULTURES

My first cultures were made merely for following out the life his-

glass was placed a single worm or a single egg ; and the cover glass

was sealed to the slide with vaseline. On account of the large num-

ber of worms and eggs in the original culture, and their small size,

it was not an casy matter to isolate an individual. It was accom-

plished by shaking a small portion of the culture in a few cubic centi-

meters of water in a small test-tube and pouring the whole out over

the surface of a Petri dish. The worms and eggs, separated in this

way, could be easily located with a lens, and picked up with a brush

without injury.

_ Fungi and bacteria developed in the cultures. In the decaying

_ mass the nematodes grew rapidly, and so far as could be judged by

comparing with specimens in the rotten plant tissue, normally. The

limited air supply seemed to cause no difficulty; at least no differ-

ence could be detected in the behavior of worms in these culture

slides and in aerated Van Tieghem cells or in Petri dishes. The

following are notes taken upon a typical preparation:

“ee

“

HAVEN METCALF

1902. One egg, unsegmented, placed in a culture slide.

Egg unchanged.

Egg segmented, apparently fourteen cells.

Egg further segmented.

Embryo distinctly formed.

Embryo moving about actively in egg.

Embryo broken out of egg.

Embryo moulting; proton of genitalia visible; worm

0.18 mm. long.

Moulting complete.

Proton of genitalia 0.032 mm. long, of female type

(Fig. 2, a) ; worm 0.34 mm. long.

Worm 0.56 mm. long; genitalia 0.15 mm. long, re-

curved at anterior end. Skin loose at both extremi-

ties.

Second moulting complete; worm 0.56 mm. long.

Three unsegmented eggs formed ; worm 0.65 mm. long.

Three eggs segmenting; six others formed.

Four eggs deposited ; worm 0.73 mm. long.

Three more eggs deposited.

Two eggs in anterior branch of genitalia segmenting.

Eggs further segmented.

Embryos in eggs fully formed and active; eggs still

within the genitalia.

Embryos in eggs moving actively.

Larvae broken through eggs and wall of genitalia,

moving actively in posterior part of body cavity;

parent worm not moving about, but alive and feed-

ing as shown by characteristic motions of valvular

apparatus of bulb. One larva measures about 0.15

mm, in length.

Parent worm alive.

Parent worm apparently dead ; genitalia decaying ; both

larvae moulting.

Both larvae still inside body of parent worm, of which

only chitinous portions remain; both larvae have

moulted ; one measures 0.38 mm. in length; its geni-

talia extend one-sixth the length of the body.

CoLTyss STUDIES OF A NEMATODE 95

Apel 14. iid: evs abaaniidiiaaite-of puvedsote: the

seven eggs deposited in the medium have developed ;

there are now nine worms in the culture; largest

worm measures about 0.62 mm.; three worms have

one or more eggs developing ; preparation moist, but

_ “ 15. Worms not moving or feeding; several coiled’ up.

_ +“ 38. +All worms more or less coiled; no motion.

_ “ 20. Condition unchanged.

_ Nothing further was done with this preparation. In another prep-

days from the time the preparation was sealed, it was noticed that

the worms were not dead,—at least they were not attacked by bac-

soe the fifty-sixth day. Accordingly the ee was

a ee oe creas cies ches ercateain et

ensued in Petri dishes and other aerated cultures. It is not improb-

"ably due to accumulation of waste products, g., urea. Apparently

_ nothing but new medium will revive the worms. This is probably

_ to be correlated with the fact that the worms naturally move about

_ over a large area, continually seeking a new substratum.

Up to the time that this quiescence begins to appear, the condi-

tions in the cultures appear to be entirely normal I have made

_ elaborate comparisons of the nematodes in cultures with those grow-

_ ing under perfectly normal conditions in decaying plant tissue ; ap-

“a parently there is not a stage or condition occurring in cultures that

_ ¢annot be matched, specimen for specimen, among those living nat-

— urally.

a Methods of observation

___ The living worm is in constant motion, and is consequently diffi-

cult to observe with high powers of the microscope. On the other

__ hand the living worm is transparent, while most killing media soon

_ fender some tissues opaque. Narcotizing the worms naturally sug-

_ gests itself as a possible method of keeping the worms quiet for

_ Observation while retaining the transparency of life. With a 0.1

"per cent solution of chloral hydrate and with a 1 per cent solution

__ 0f cocaine hydrochlorate I had fair success ; the only objection being

96 HAVEN METCALF

the slowness of action: worms treated with chloral do not entirely

cease motion for thirty minutes. The most practicable method of

preparing worms for observation was by treating them with a 0.01

per cent solution of mercuric chloride; death was practically instan-

taneous, and the worms did not begin to lose transparency for from

thirty to forty-five minutes ; allowing time for drawing and observa-

tions.

Obtaining sterile nematodes

In order to make inoculations upon living plants to determine

whether the nematodes have any pathogenic power, it was first neces-

sary to secure worms free from bacteria, fungi, or any other organ-

isms. This proved to be by no means an easy matter. I first tried

to free eggs from bacteria and fungus spores by making plates from

them in the usual way, with asparagus agar. While by this process

the germs were scattered, some bacteria or fungus spores remained

so near the eggs that the latter could not be absolutely isolated.

Various methods of sterilizing the eggs by chemical means were then

tried : eggs were washed for varying lengths of time in various solu-

tions of mercuric chloride, carbolic acid, thymol, copper sulphate,

dilute hydrochloric acid; with the uniform result that whatever de-

stroyed the plant organisms destroyed the eggs also. I then hit

upon the method of washing eggs in sterile water, placing them in a

watch glass, and changing the water repeatedly with a pipette. The

eggs.sink in water ; so also do most bacteria, but spores of Fusarium

and of terrestrial fungi in general float. Hence by this method the

eggs were easily freed from fungus spores, but not from bacteria.

But by repeated washings the surface of the eggs was largely freed

from bacteria, and the number of bacteria in the water greatly re-

duced. Then the eggs were placed in liquefied agar tubes at low

temperature, and poured plates made in the usual way. In the

plates several spots of fungi appeared, and many bacterial colonies.

But out of the twenty eggs used five were so situated that after two

days’ growth at room temperature no colonies were near enough to

touch them. These eggs were then transferred to plates of sterile

agar by using a special form of flat oese, a description of which will

shortly be published. In this way eggs were secured free from all

micro-organisms.

The sterile agar into which the eggs were transferred was a one

per cent asparagus juice agar, sufficiently moist, but rather stiff. In

CULTURE STUDIES OF A NEMATODE 97

this medium the eggs developed, the larvae moulted, but after the

_ first moult made very little growth. At first they moved about

freely, but after from ten to fifteen days they curled up and became

quiescent. That they were free from moulds and bacteria was con-

___ As I was uncertain why the worms failed to develop, and was in-

I es tee diicaky to tajary received in the washing, I

Fepe the experiment twice, with similar results. It then oc-

to me that the difficulty might be with the medium: that

of decay might be necessary food. Accordingly I inocu-

; & ated a flask of one per cent asparagus juice agar with the Fusarium

MU Ectcsis ot one of the original poured plates: after allowing the

Mass to decay for two weeks I heated the agar, filtered out the fungus

_ fiber, and sterilized the filtrate. Sterile eggs were then placed in

Sterile plates of this agar ; they developed rapidly and normally, and

__—‘ This decayed agar, however, was more nearly liquid than the nor-

_ mal agar. In order to show whether degree of solidity might not

_ have as much to do with the behavior of the nematodes as presence

of decomposition products, I placed other sterile eggs in a 0.25 per

cent asparagus juice agar. These developed, not as rapidly nor as

_ vigorously as those in the decayed agar ; but quiescence did not ensue

until several generations had developed. But as decayed agar was

distinctly the best medium, it was used wholly in growing sterile

I have already mentioned that these nematodes move about ac-

__ tively, and over considerable area if given range. Their food also

passes quickly through the alimentary tract; it occurred to me that

_ these facts might be utilized in devising a method of freeing the

"at one end. Active worms were then placed in the upper end; they

‘ SINICA Geren 06 wove toward the siolet end, reaching it in a

few hours ; when they were transferred to the next disn and the

_ through sterile medium would free the worms, inside and out, of

_ germs. But such did not prove to be the case. Although the num-

98 HAVEN METCALF

ber of organisms in and about each worm was greatly reduced, as

was shown by the number of colonies developing along the trail, no

worms could be obtained entirely free from either bacteria or fungi.

This suggested what later experiments have demonstrated, that these

nematodes are efficient agents in disseminating micro-organisms.

Biochemical Relations

This nematode when grown in cultures exhibits peculiar and inter-

esting relations to its substratum, which I have not worked out.

The medium becomes more alkaline, probably in consequence of the

considerable quantity that passes through the worms.

The frequent occurrence of the nematodes with Fusarium sug-

gests some vital relation of that fungus or its products; whether or

not there is such relation, it is certain that some other fungi exert

a deleterious effect upon the nematodes. I noticed that the nema-

todes died in a culture which had become contaminated with a black

Aspergillus. I inoculated two other plates of worms with this fun-

gus with the same result; the bad effect of the fungus growth was

unmistakable. No investigation was made of the by-products of

this Aspergillus, which are probably poison. Might not the line of

investigation here suggested be fruitful if followed out with reference

to certain pathogenic nematodes? Nothing is known, for example,

regarding the relation of gall-forming nematodes to plants other than

their hosts.

To dryness the live nematodes are fairly resistant, but not so much

so as might be expected ; in agar cultures dried at room temperature

for twenty-four days the nematodes have failed to revive. The eggs

do not seem to be much more resistant than the living animal, a fact

which may be correlated with their frequent internal development.

The nematodes are unaffected by sunlight. No attempt has been

made to work out their relation to salts, disinfectants, or other chem-

ical substances.

INOCULATIONS

Inoculations of pure cultures of nematodes have been made upon

young Coleus and Geranium plants, upon sugar beets, and upon the

iron pea. The standard methods of inoculation were employed, and

each inoculation carefully checked; so the methods need not be de-

scribed in detail. Suffice it to say that wounds were made on parts

CULTURE STUDIES OF A NEMATODE YI

the plants under ground, and the nematodes placed on these spots.

e wounds were kept moist. Although in every case the worms,

at least some of them, lived, decay of the plant tissue did not ensue

‘in any case ; instead, the wounds healed normally. Evidently, then,

_ the nematodes alone have no pathogenic power.

_ More interesting results were obtained, however, upon using nema-

tox ee re eS ee

beets, already referred to. Some of these were placed on

; SEES tae: live beet, with the prompt result of: the decay of the

_ beet by the bacterium. The experiment was also made of putting a

antity of nematodes from the same source on the surface of the

il around four potted beets. No decay ensued. But when the

periment was modified by wounding the surface of the beet under

soil, decay ensued in three out of four beets. The experiment

§ repeated with two other beets; both decayed; and examination

ie the decaying spots showed the nematodes to be present on the

_ Cuttings of Coleus were placed in a pot of earth, and a large num-

cides frome « cahare cttsincd originally fram © Coleus

_ cutting which had “ damped off,” were placed in the soil. Fusarium

present in the culture. Examination of the cuttings in ten hours

"showed that the nematodes had congregated around the cut ends

the plants. Later about one third of the plants “ damped off.”

ov led me to examine again fresh wounds of sugar beets, near

_ which nematodes had been placed. Without exception the results

_ showed that the nematodes gather about wounds ; probably for the

plant juices, upon which they seem to feed. Herein, then, lies their

_ real relation to plant decay: they are carriers of germs of decay to

_ wounded places. They are, however, necessarily from their struc-

_ ture, incapable of themselves producing the wounds.

SUMMARY

1. A nematode, Rhabditis brevispina (Claus) Biitschli or a closely

--Felated form, is commonly and widely associated with decay in cer-

2 . The nematodes grow readily in agar cultures of plant juice if

sufficiently fluid; better in decayed media. So far as can be deter-

a en exmniention, the nematodes grown in cul-

100 HAVEN METCALF

tures are similar in all respects to those living under absolutely

natural conditions.

3. Absolutely sterile cultures of the nematodes can be obtained by

washing the eggs, and afterward making poured plates with them

in the usual way.

4. In cultures the nematodes are killed by the presence of a certain

species of Aspergillus.

5. The nematodes seek wounded places on the underground parts

of certain plants, probably in order to feed upon the plant juices.

If they bear spores of pathogenic organisms they necessarily inocu-

late the plants; and as they feed on decaying plant tissue, becoming

covered with the germs of the decay, they readily transfer the disease

from plant to plant.

ACKNOWLEDGMENTS

These studies have for the most part been carried on in the zoolog-

ical taboravory of the University of Nebraska, and under the direction

of Dr. Henry B. Ward, to whom I acknowledge many obligations.

CULTURE STUDIES OF A NEMATODE 1o1

i 4

ere rene Science, N. S., XV, No. 372, p. 274.

102 HAVEN METCALF

EXPLANATION OF PLATE VII

All figures drawn with Abbé camera lucida; 1, 3, and 6, from narcotized

specimens, the remainder from specimens freshly treated with mercuric

chloride.

Fig. 1. Larva at time of first moult. a, proton of reproductive organs.

Fig. 2. Portion of nematode from a culture sixteen days old. a, repro-

ductive organs.

Fig. 3. Nematode from culture twenty-six days old.

Fig. 4. Posterior end of adult nematode. a, gland cells.

Fig. 5. Anterior end of the same specimen.

Fig. 6. Portion of middle of nematode from a culture twenty-two days old,

showing posterior branch of reproductive organs.

“ DATA FOR THE DETERMINATION OF HUMAN

| ENTOZOA

By HENRY B. WARD

WITH FOUR PLATES

‘The attention of the scientific world has been powerfully drawn

Si etopecaites of man by recet Gacoveres demonstrating ther

_ records of disease. Tests O teenies ont of Oc toca

_ found worms is recorded not only in the first medical writings of

re on een Santon of Be Betray ant

p aretens: and in a few instances the records include accurate

Statements regarding the cause and remedy for the disease as well

as the means of distinguishing different forms of such parasitic

4 es ee aes ey Set steation

effects which they produce in the human organism.

q ago Leuckart listed thirty species which had been

-. and, in company with Virchow and a long list of

other investigators, called repeated attention to the deleterious effect

_ Certain species exert. Braun’s more recent work (1902) dis-

cusses of in and doubtful species fifteen Trematoda, twenty

__ Cestoda and thirty-eight Nematoda, besides thirty to forty Protozoa,

which have been recorded from the human host. In studies on the

various groups which I have recently published this list is increased

by two species although the interval between the publication of

Braun's lists and my own is not a full year.

104 HENRY B. WARD

’ The various studies, however, have chiefly been made on forms

found in the old world, and the well known species are in the main

those of European countries. Within very recent times these studies

have begun to be extended over other lands. All the new forms

recorded during the last five years have been extra-European, either

new species peculiar to other lands, or new regions within which

known forms have been found to exist, so that one may say the

greatest advance has been in knowledge of the geographical distri-

bution of human parasites, although the life history of many species

has also been strikingly elucidated. The previously recorded large

number of isolated cases of the occurrence of certain species has been

supplemented by other cases showing more general occurrence or

wider distribution, the results of which have been to demonstrate

that these parasites are far more common and widely distributed than

was believed heretofore. The accompanying table which lists all

human parasites of the various groups of worms heretofore recorded

with a statement of the regions in which they are known to occur

will be of value as indicating the present knowledge on the subject.

It has seemed to me best to confine the list to the worms and to ex-

clude the protozoan parasites for the double reason that the latter

are very imperfectly known and it would be difficult to present a

satisfactory list, and in the second place that they are also more

difficult to determine, even by the professional microscopist, and

present insuperable difficulties to the ordinary practitioner.

Taste I.

~~“ Fi

14/4]

Leptodera Nicll Larva | Accidental? | * One

he 7" Adult | Occasional * One

Filaria medinensis ae Normal FI tell Retell Oe Med , Abundant

Uncinaria duodenalis t Larva “ * |) ee) #2? se

Eye:

ee cellulosz Larva Erratic is Rare

inococcus ymorphus a] “ * oe

Filaria loa eet Adult Normal z i giz Frequent

“« lentis Young ? ?]?]? Uncertain

“« conjunctive Adult | Occasional | * Rare

..- Hibs A us. bl is ih. hey

eG. | eS eset yaoS Ree NCIC Bee we

fa te

sl oe fio Hee edd} |

t ~ [fie tied: & UP ERD Ee oil on:

BE |

Ht lg sli

106 HENRY B. WARD

Taste 1.—Continued.

= ;

i/4)*|

Metorchis Adult | Occasional * Once

Dicrocoelium lanceatum “ “ *iti*ititi¢| Ree

Cysticercus cellulosae Larva Normal bel t “

Echinococcus polymorphus as “ all Frequent

ie Small Intestines : ss

asciolopsis Buski Adult oe Rare

Fasciolopsis Rathouisi “ Occasional . Once

Opisthorchis felineus se Erratic ball ed Rare

ms “ — “ “ : me z “

Dibothriocephalus a - s stall Datall Wad Abundant

“ “ “

Dipylidium caninum “ “ * * Y “

ymenol nama ‘ ormal *#ia)|#i#

" 65 ™ diminuta ‘ eel * . * > = ge

o lanceolata a “ * Once

Davainea madagascariensis | ‘ Occasional ? *\* ad Rare

os asiatica Adult ? * Once

Tenia solium $e Normal | */| */| */| * Abundant

‘* serrata oe ? e Twice?

* saginata ne Normal *);e;e)¢ Abundant

“africana “s 4? . Once

“ confusa “ «? * Twice

* hominis “ ? * Once

Strongyloides stercoralis “ Normal * eel eel ae |e Abundant

Trichinella spiralis? ea “ * ieee) # * “

Strongylus subtilis ss “ *|* Twice

Uncinaria duodenalis “ “ *)#* | *# | | #2 Abundant

“ americana “ “ * ** | #? “

caucasica x ? * Once

Ascaris lumbricoides ss Normal *i|#) a) @ Abundant

* canis i Occasional | * * Rare

“maritima “ “ * Once

Oxyuris vermicularis “ Normal ® *| * Abundant

Gigantorhynchus gigas ** | Occasional | *? t Rare

“ monili “ “ * “

Echinorhynchus hominis a ? * Once

Large Intestine :

Gastrodiscus hominis “ Occasional ? * Twice

Tricburis trichiura “ Normal | *| *#/ #/| #| # Abundant

Oxyuris vermicularis Female “ *\|* | *) # “

Echinococcus vmvbiigl us | Larva se * * Rare |

Dioctophyme = Adult | Occasional | * tit “

Bladder : ;

pellio “ Accidental | * Once — 1

Anguillula aceti “ “ * Twice

Filaria restiformis “ss ? * Once

THE DETERMINATION OF HUMAN ENTOZOA Io7

re 7 Taste I.

EXPLANATION OF SIGNS.

** Recorded from man ; autochthonous to region.

* Recorded from man ; probably endemic, though often secondarily.

& Recorded from man ; probably acquired elsewhere.

_ + Recorded from some other host, hence possible in man. This entry is without

ee reference to the particular organ under consideration.

_ ? Record open to

1 Distribution of larva after that of adult form.

| “ “* adult “ “ ** larval “

It may be confessed at the outset that the table is probably incom-

plete. The individual records are much scattered, and in such form

Sel eats demand extensive critical editing. It would be improbable,

_ then, that, even with the great care which has been exercised, all

Saanieds should have been included. So far as the list concerns

Europe and the United States, however, I think it may be said that

it is most nearly complete and includes all but the most obscure

records up to the present date. It should nevertheless be borne in

mind that one may certainly expect further evidence of the presence

of some of these species in unrecorded regions and of the existence

of new species in most of the regions of the world. Additional

strength is given to this general premise by the discoveries which

have been made within the past decade in these United States.

Thus Thayer has demonstrated the existence here of the Indo-

oe. European Strongyloides stercoralis, White has discovered the Asiatic

Opisthorchis sinensis, 1 have found the Asiatic Lung fluke, Para-

gonimus Westermanii and a new human tapeworm, Taenia confusa,

while Stiles has in addition to records on the vinegar eel, Anguillula

aceti, and other forms new as human parasites here, contributed the

most important of all these studies, namely that on the widespread

q _ occurrence of a new hook worm, Uncinaria americana, which is of

___ feat etiological significance over large areas of our country.

_ The history of helminthology shows a characteritic vibration

from one extreme of belief to the other regarding the importance

to be attached to these forms from the clinical standpoint. In the

belief of the medical profession two hundred years ago there was

Wo disease, real or imaginary, which was not due to the presence

D and effect of some kind of parasite. Each ailment had its particular

“worm” in its characteristic location. This was a direct result of

108 HENRY B. WARD

the endeavor to reduce every malady to some definite cause, and from

a joining of the unknown sickness with the parasites of which they

knew as little. Under the influence of study and of increase of

knowledge regarding the parasites, such a theory was seen to be

untenable, and the movement in the opposite direction began, a

tendency which may be said by this time to have passed its height.

This opposite extreme has been manifested in our own land, since

there has prevailed during recent years among the medical men of

this country an exaggerated idea of the unimportance of human

- parasites. It has been very generally maintained that the country

was less infested than the Old World, or that the forms, after all,

were of little significance in the etiology of disease. I am of the

opinion that the discoveries referred to furnish ample grounds for a

modification of the position of indifference heretofore assumed, and

in the treatment of disease call for more careful consideration of

such forms as possible factors of etiological significance. The clin-

ical importance of parasites is generally recognized in such cases as

Bothriocephalus anemia, of which only a very few instances are on

record in the United States, and for a few other species also, but

similar significance has not been accorded to most forms.

It is true that internal parasites are very widely distributed and

that scarcely any individual is entirely free from them. They are,

however, usually present in limited numbers, and are believed to be

harmless if infrequent or of small size. This does not seem to be

strictly correct, for while it is doubtless true that the effect of a

single parasite, or even of a considerable number of minute size, is

small and difficult to measure or estimate, it is equally clear that even

this is a certain drain on the host. Furthermore, the tax on the

host is in proportion not only to the number and size but also to the

habits of the parasites present. Thus there is a great difference

whether the parasite is active and growing in the alimentary canal

or some other cavity in the body of the host, or passively resting in

the midst of the tissue of some organ.

While encysted parasites exercise a continued and sometimes

serious pressure on adjacent tissue, yet the draft on the host by free

parasites is much the greatest and manifests itself in three ways.

The parasite requires a certain amount of food for its support; this

it takes directly from the host, either from that which the latter has

digested for its own use, if the parasite be in the alimentary canal,

THE DETERMINATION OF HUMAN ENTOZOA 109

or from material which the host has formed to perfom certain work,

__ as in the case of blood parasites, or from the tissue of the host, as

__ ome intestinal worms which feed on the cells composing the wall

__ of the intestine. In any case the host expends at least the extra

___-‘-€Mergy necessary to procure and digest the food taken by the parasite,

and this extra labor will be directly in proportion to the amount of

__ food taken, or in general to the size of the parasite and to its

In the second place the parasite occupies a certain amount of

___ Space and correspondingly reduces the calibre of the tube in which

it lives. Unless a considerable number are present this is hardly

__ @ practical stoppage for the alimentary canal, although in several

__ fecorded cases death has followed occlusion of the canal by a mass

of Ascarids, but in the case of the blood system a vessel may be

____ ¢losed or a clot formed by the presence of even a very few parasites.

___ In the third place, active parasites will, by their movements, give

___ fise to a certain amount of irritation and inflammation of the mem-

branes over which they move. This is in some ways, perhaps, the

most serious trouble which a few parasites can cause, and it is much

____ imereased if in the special case the parasite obtains its food at the

«expense of the tissues of the host, that is, if it tears or consumes

___ €ertain lung flukes which may chance upon some large blood vessel

and in this way produce even fatal hemorrhage. In the alimentary

canal a single Ascaris may perforate the wall and induce fatal

peritonitis as has been observed several times in recent years. It

; haemoglobin in the alimentary canal of many nematode parasites, the

___ pathologic effect of whose activities must be counted much more

a important than heretofore estimated by reason of this blood sucking

Ito HENRY B. WARD

habit. Thus in severe cases of uncinariasis the amount of blood

lost from myriads of minute hemorrhages imparts a characteristic

reddish-brown color to the feces, and is so extensive that fecal matter

will leave a distinct blood stain on blotting paper. At the same

time the intestinal wall becomes seriously affected, and affords

places of easy attack for any pathogenic germs which may be pres-

ent. This indirect damage may be very serious in the individual

instance and may include primarily or secondarily undesirable re-

gressive or progressive histological changes, inflammatory processes,

and disturbances in the circulation.

Another source of danger from parasites is one which has long

been surmised but only recently demonstrated. A number of

investigators have shown that various Cestoda, Acanthocephala, and

Eunematoda contain definite poisons (toxins) which, when extracted

and employed experimentally, affect particularly the nervous system

and the formation of blood. The continued formation and giving

off of such substance would explain the apparently excessive results

of parasitism in some instances, results which are shown prom-

inently in reflex nervous symptoms. In a certain proportion of

cases, pernicious anemia is the result of this toxic effect, and is

accompanied by a considerable mortality, reaching seventeen per

cent according to one report regarding Bothriocephalus. Whether

the poison is elaborated by the parasite, or is produced by pathologic

processes in the worm or by its death, as well as the ground for the

variability in the toxic action of different specimens, are questions

as yet undecided. It has been shown, however, that extracts from

different species of helminthes vary considerably in toxic power.

Vaullegeard has isolated two toxic principles, one of which acts upon

nerve centers and the other upon muscles, and many symptoms

produced experimentally by the injection of these substances are

analogous to those manifested in parasitic disease. According to

this chemical theory the troubles caused by parasites are due to the

formation of toxic substances more rapidly than their elimination

by the host, and their consequent accumulation in the system. A

striking instance of the actual effects of parasitism on a large scale

is set forth by Stiles (1902) in his description of the general anemic

condition and the lowered physical and mental vitality of the families

and communities where Uncinaria americana is common. These

considerations are sufficient to show the greater numbers and more

THE DETERMINATION OF HUMAN ENTOZOA mmr

_ serious effects of human parasites in our own country than has been

pe view of these facts it would seem hardly necessary to emphasize

+ ‘action of some much doubt exists, and there are others which are

believed to be indifferent to man. Some are short-lived, and from

g oe of their life history one may conclude that they are not

er a O-xyuris vermicularis, or threatens to

"infest the host with dangerous larval stages as in the pork tapeworm,

ahaa Furthermore, even of those whose i injurious effects

a I Gsscrees socarencly with chat Bsr epetigariaepiik¢-

_ to deal in the individual instance. To-day no one would be satisfied

nee ee Segecee Of “fever. ent how can the disguosis of

question. Wir Gad Gade decdesieiht bee chine

* eo ae creo aid it oy exe vey aoa

secured. They do not involve any complicated technique or the

__ tse of high powers and a series of time-consuming cultures is en-

_ tirely unnecessary. The determination is most readily made from

a fresh material, and while it should be repeated several times in order

to exclude all possibility of deception or accident, it requires only

" Dirief time, and the use of comparatively low magnification A con-

_ sideration of the factors involved will make the matter clearer.

Evidence of the presence of parasites will ordinarily be obtained

__ by an examination of the blood, sputum, urine or feces. The first

_ three are very frequently examined in the diagnosis of disease, and

asa matter of fact they rarely furnish evidence of parasitism. So

_ far as I have been able to learn fecal examinations are rarely made,

and yet by them evidence of parasitism would be most largely

_ furnished.

They are neither difficult nor in any conspicuous way disagreeable.

112 HENRY B. WARD

A quantity of fecal mattar may be shaken up with water and by

successive decanting and diluting the more solid portions i

the parasitic material will be obtained in concentrated form. A

small portion of the suspected feces may also be diluted with a

few drops of water and after being broken up examined on a slide

under the microscope to demonstrate parasitic specimens too small

to be detected by the unaided eye. The negative evidence of a

single such preparation can not be accepted as final but must be con-

firmed by a series of observations.

By means of such examination one finds sometimes specimens of

the entire adult parasite, recognizable fragments of the same, its

embryos or its eggs. It is comparatively rarely that one encounters

specimens of the entire parasite, and unless the latter are very abund-

ant such specimens may easily be overlooked if not of such size as

to be visible to the naked eye. One is aided, however, in the detec-

tion even of small round worms by the definite form with its distinct

contour, by the peculiar appearance and sometimes by the move-

ments of living specimens. There is opportunity for confusion with

fragments of undigested matter, particularly vegetable tissue which

will be discussed later, and the diagnosis should be confirmed by

careful microscopical examination of the suspected objects.

The identification of the parasite by some recognizable fragment

of the body is regularly made only in the case of the tapeworm

which is determined by the passing of segments or proglottids at

stools. While the precise determination of the species of tapeworm

from the separate proglottids is a matter of more difficulty than

ordinarily believed, the cases of confusion resulting therefrom are

not such as to introduce any difficulties in the accepted treatment.

In passing it may be noted, however, that the determination of tape-

worm proglottides as flukes on account of their active independent

movements is a frequent error. The examination of such struc-

tures even with a hand lens will show the absence of features char-

acteristic of the flukes.

The determination of embryos is not attended with difficulties so

far as the different groups are concerned. The embryo of the flukes

is oval or elongated, covered with a coating of cilia and so delicate

that pressure of the cover glass will crush it completely into granular

fragments. These embryos are not common and under normal cir-

cumstances do not desert the egg shell; but when brought under

THE DETERMINATION OF HUMAN ENTOZOA 113

conditions of varied osmotic pressure or chemical influence as when

feces are diluted by water or urine is changed in acidity on standing,

he shell may open and the embryo emerge. This may often be ob-

served on the slide under the microscope.

The embryo of the tapeworm, known as an onchosphere, is pre-

ly characterized by the presence of three pairs of small hooks

ich lie near one end of the spherical mass. Such embryos are not

id free unless some accident has ruptured the membrane, or em-

by which each is surrounded.

The nematode embryo is elongate, or vermiform, and possesses a

outer cuticular layer which is highly refractive and appears

inder the microscope as a clear structureless boundary. The surface

often shows striations on careful examination, and spines or papillae

are found near the mouth at the anterior end. The alimentary canal

_ shows at least two distinct regions, an oesophagus or pharynx lined

by inverted cuticula and a mid-gut without such lining. In the

_ former various parts may often be made out. A clear area near the

center of the worm, consisting of one or a few large cells is the

proton of the reproductive system. The size and position of this

genital area are of importance in the determination of the species

although in many forms it has not been accurately described.

_ The characteristic features of individual species so far as known

re sufficiently fully indicated in the annexed Table II. For the

‘distir of individual species of Filaria by means of the table

“Whe data are only partially satisfactory as these forms have been but

little studied and are imperfectly known. These worms are prob-

ably rare in our fauna unless it be in the southern states and

methods of distinguishing them are yet to be worked out.

__ If any evidence of parasitism is discovered, it is most frequently

___ by the occurrence of eggs. And it is in dealing with these structures

_ that the greatest difficulties in precise determination are experienced.

_ This is in large part due to the inaccurate and insufficient knowledge

concerning them. A comparison of the original sources with vari-

‘ous manuals shows that serious errors in measurements have crept

nm and that mention of important and characteristic peculiarities has

often been omitted. I have accordingly deemed it wise to include

critical review of these features with illustrations for all species

known as human parasites.

The eggs of parasites may be distinguished on the basis of form,

HENRY B. WARD

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THE DETERMINATION OF HUMAN ENTOZOA mms

___ Size, texture, and other individual peculiarities. Any one of these

__ elements is usually insufficient; but with the exception of a few

____ forms of rare occurrence which are imperfectly known, the group

of characters enables one to make a determination. In reaching a

_ decision the observer should, however, keep in mind some general

___ All eggs are not mathematically uniform in size; the range of

variation is in most cases small and the average readily obtained

by measuring ten or a dozen specimens taken at random. In many

___ €ases only the average size, however, has been recorded. The same

comparison of a number of specimens will serve to eliminate abnor-

malities of the individual egg and to give a correct idea of the

The occurrence of constant differences in size between the speci-

ens measured and the descriptions given for a species under con-

sideration creates a prejudice at once in favor of the view that the

two species are distinct, and some of the supposed wide variations

in the eggs of certain species have been found to be due to the

confusion of two or more closely related forms under a single

specific name.

___ Errors in the general interpretation of these structures are also

‘mot infrequent. The eggs of distomes have more than once been

__ diagnosed as coccidia to which they bear some superficial resemblance

im external form. They are, however, usually larger and differ

____ fadically in texture and in internal structure as will appear on com-

_ parison of the descriptions or figures given in any good text. Thus

_ Braun (1902, p. 75) states positively that the case diagnosed by

_ Thomas (1899) as Coccidium oviforme in a brain tumor must cer-

; ee tes rene 0 the view et

4 bodies were distome eggs. In one case at least

q Esa deas gure acts tertlind as'c cee gous ant

___‘The eggs of the Trematoda, or flukes, may be characterized in

_ _ general as ellipsoidal or ovoidal. The proportion of length to breadth

_ Varies so considerably in different species that the form may be

_ that of a spindle in one case, or it may even approximate the sphere.

Im rare cases the egg is flattened on one side, as in the case of

Tiiiiitdelien lanceatum according to Leuckart. One finds as a

_ universal characteristic the presence of a lid which is absent in fact

116 HENRY B. WARD

only in a single case. The lid ordinarily conforms to the curvature

of the shell, though in rare instances it appears more flattened. Only

exceptionally does one find the opposite end of the shell prolonged

into a filament of rudimentary character in this group. Where

present such filaments constitute valuable criteria in the determina-

tion of species. Even in such genera as normally possess them,

however, one may find them lacking at times. A knob-like thick-

ening which is present at the lower pole of many fluke eggs may be

regarded as the rudiment of a filament.

In appearance the trematode egg varies from light to dark brown

in the extreme case reaching almost a mahogany color. When first

formed in the body of the parent individual they are uniformly

nearly transparent, a feature which is preserved permanently only

by Schistosoma haematobium, whereas in other species the color

begins to appear with the passage of the egg into the uterus, and

has reached its final condition at the time when the egg is extruded

from the body of the parent. The number of eggs produced by

the trematodes which inhabit the human body is large, so that even

in the presence of slight infection one finds considerable numbers

discharged and their production is maintained over a considerable

time. Special data regarding various species are given under the

appropriate headings.

Gastrodiscus hominis is a human parasite which has been found

only twice, and concerning which the data at hand are not extensive.

Leuckart says that the eggs are of oval form, 0.150 mm. long, and

0.072 mm. broad. They are supplied with a firm shell, which at

the attenuated anterior end is cut off in the form of a lid. Leuckart

notes, moreover (1894, p. 458), that Giles, who was never able to

demonstrate the eggs of the parasite in the excrement of the host,

propounded the somewhat doubtful hypothesis that the eggs are

set free only after the death or expulsion of the parasite.

The common livet fluke, Fasciola hepatica, has been studied by

many observers. One of the best descriptions is given by Sommer

(1880, p. 84). The large, well formed egg in the coils of the uterus

(Fig. 12, Pl. IX) measures 0.13 mm. in length by 0.07 mm. in

breadth, and up to a length of 0.142 too.150. The shell which is at

first thin and transparent, is without irregularities save at the

pointed pole where a few such occur frequently. The opposite end

of the egg is provided with a lid and is regularly rounded or even

THE DETERMINATION OF HUMAN ENTOZOA 117

a “When the egg comes to be deposited, it has

: SEE os intense beown eclor, which makes the investigation of

_ the contents very difficult. Among them one may distinguish,

however, in the earlier stage, a single homogeneous, clear, highly

refractive mass of protoplasm, which is the single germ cell. It

lies surrounded by a mass of opaque, granular cells, which constitute

the yolk mass of the egg.

In Fasciola magna, the large American fluke, Stiles (1895, p. 242)

. who has investigated the species very carefully, says that the eggs

a 11, Pl. IX) can hardly be distinguished from those of F.

cas ea Selling uhic

: F. magna F. hepatica

Long Broad Long Broad

mm. mm. mm. mm.

____ It should be borne in mind that Stiles’ measurements of F. hepatica

were made from American specimens, and it is possible that a

_ epee of size may be found in such as have been produced under a

climatic environment. In case of the suspected presence

of F. magna in man here where it may some time well occur, as does

; the closely related European species in numerous cases on record in

___ Europe, Stiles’ measurements are the most important. It has not

yet been shown that the eggs differ in size when produced by para-

Sites in different hosts, although it is well known that the parasites

__ themselves undergo some modification in size and form.

a Fasciolopsis Buski (Lank.) which has been hitherto little known

has received careful examination within the last year at the hands

_ of Odhner. Regarding the eggs this author says (1902, p. 578):

___ The eggs which are much mixed with aborted specimens are present

in large number and measure in length 0.12 to 0.126 mm. by a width

of about 0.077 mm. They resemble in all respects the eggs of the

___ ® This is not true of the figures given here (Pl. IX, Figs. 11, 12) as the

_ HMlustration used for F. magna represents the minimum, rather than as should

have been the average size for eggs of this species. On the other hand it is

also doubtful whether the table quoted from Stiles actually supports his con-

tention as to the relative magnitudes of the ova.

118 HENRY B. WARD

large liver fluke (Fasciola hepatica). Unfortunately the author does

not give any representation of these structures.

The reports which have been published regarding the egg of

Paragonimus Westermanii are considerably at variance. The orig-

inal discoverer of the species Kerbert (1881) gives the measurement

of those obtained from the tiger as 0,080 by 0.045 mm. The original

account of the species in the United States (Ward, 1894, p. 356)

states that the eggs vary from 0.096 by 0.048 mm. to 0.118 by 0.050

mm. with an average size of 0.102 by 0.053 mm.

According to Stiles (1900, p. 603) the average measurements of

specimens taken from cysts in the lungs of Kentucky hogs are 0.078

to 0.096 mm. in length by 0.048 to 0.060 mm. in breadth, with an

average size of 0.0856 by 0.0532 mm. The most recent investi-

gation of the species by Katsurada (1900a, p. 508) gives the follow-

ing data for eggs taken from the sputum of the human host:

Minimum 0.0875 by 0.0575, maximum 0.1025 by 0.0525 mm. with

an average size of 0.0935 in length and 0.057 in width. He says

that the fully formed egg (Fig. 2, Pl. VIII) has an oval, clear

yellowish brown, relatively thin shell, broad at one end, and some-

what tapering at the other; the tapering end has the thicker shell,

and the other end shows a somewhat flattened small lid. The con-

tents of the egg within the shell are covered by a thin membrane and

in the space between the granular yolk masses, a clear viscous fluid

is found.

The measurements as stated by different authors have been put

together in an outline sketch which represents the differences in

graphic manner (Fig. 1, Pl. VIII). It will be noted that there are

only two wide variations from the general size as given by the

majority of authorities. Regarding the eggs which are unusually

large, according to the measurements of Baelz (1880), it may be

said that the same author later (1883) gives lesser measurements

for specimens obtained like the first from the sputum of man, so

that one may suspect an error in the earlier record. On the other

hand, the measurements given by Yamagiwa (1890, p. 455) were

taken from sections of the brain and lungs of man. Their sub-

normal size may be due to an error in measurement, or to a determin-

ation of the size from fragmented specimens, or to eggs situated

obliquely in the section and consequently reduced in length. It is

difficult to believe that all records can be correct as they stand,

unless some other species is concerned.

THE DETERMINATION OF HUMAN ENTOZOA 119

_ The eggs of Opisthorchis felineus have been described by Braun

é (1902, p. 158) as oval, with sharply marked operculum at the

_ pointed pole and containing an embryo in which cleavage is already

well advanced. They measure 0.030 by 0.011 mm. (Fig. 8).

; his sinensis has been investigated by a number of ob-

servers. Ijima (1887, p. 11) says: The eggs are unusually small,

meas 0.028 to 0.03 mm. in length and 0.016 to 0.017 mm. in

breadth. In the anterior portion of the uterus, where the egg shells

have assumed a dark brown or dark olive color, embryos are already

formed (Fig. 6, Pl. VIII). In the interior three distinct remnants

of yolk matter are seen in addition to scattered yolk granules.

_ Embryos can be forced out of the shell by a sharp tap on the cover

_ glass. Such have an elongated shape and measure 0.025 mm. in

ft, The body tapers slightly towards the posterior end, and

) an of head papillae. The posterior portion con-

tains small clear cells, probably terminal and there are no eye-spots

the same species Katsurada says (1900, p. 481) that the pre-

viously accounts agree well with facts, but cites as an

especially accurate investigation that of Dr. Osafune, who measured

_ §00 eggs from feces and found that the majority were from 0.027

to 0.030 mm. long, and 0.015 to 0.0175 mm. broad, exceptionally

specimens were found with a length of 0.035 mm. and a breadth of

_ 019 mm., and on the other hand such as were only 0.02 long and

_ ©0157 broad, or 0.0225 long and 0.015 broad were also present

(Fig. 7, Pi. VIII).

_ _The Egyptian Fluke, Heterophyes heterophyes, has been carefully

(1894, p. 32) who speaks thus about the egg:

| y more pointed at the lid pole than at the op-

Sir ac: ey omens lenge of Ong man. by 8 greatet breadth

Dente

int

Sore 9, Pl. anes, The latter possesses, so far as one can deter-

_ mine through the egg shell, an elongated cylindrical form, and car-

_ Hies at the anterior end a weakly marked projection. The surface of

ae vee :

aos

120 HENRY B. WARD

the body is covered in its entire extent with cilia which are most

evident in the anterior region. In the posterior end large trans-

parent spheres, 0.008 mm. in diameter, are the germ cells of the

embryo.

In Dicrocoelium Miecolabial (Fig. 3, Pl. VIII) the eggs are, accord-

ing to Leuckart (1889, p. 376), ovoid in form, with the lid end

notably flattened, while the same is true for one side of the shell

(Fig. 4). In size, as well as in detail, there are many differences

in form among the fully developed eggs. The length varies from

0.04 to 0.045 mm., and the breadth from 0.02 to 0.03 mm. When

first formed, the egg is, as in many other cases, almost transparent,

but during the passage of the uterus it becomes very dark brown.

At the same time the embryonic development is being completed,

so that the eggs when deposited contain an embryo which is already

fully developed. Leuckart gives the length of this embryo accord-

ing to his own measurements as 0.026 to 0.030 mm. and the breadth

as 0.016. The embryo occupies exactly the center of the egg so

that an even space intervenes between it and the shell everywhere.

There is also a mass of granular matter, usually at one end, sur-

rounding the head end of the embryo like a cap, and more or less

completely concealing it.

Three other trematodes have been reported from the human host,

namely Opisthorchis noverca, Fasciolopsis Rathouisi and Fasciola

angusta. There is on record but a single case of each, and the eggs

are not sufficiently well known to make them available for deter-

mination. Moreover in the case of such an exceptional species

more than the evidence furnished by the egg would be necessary

in order to establish its occurrence in the human host.

The eggs and embryos of Schistosoma haematobium have been

carefully studied by Looss, whose observations are reported by

Leuckart (1894, p. 521). According to this investigator, whose

studies were made upon eggs discharged with urine, such either

contain an embryo ready to hatch out, or are dead and calcified. The

normal eggs are somewhat variable in form, though in general

spindle shaped with median enlargement (Fig. 10, Pl. IX). At

the posterior pole is a characteristic filament, often very incon-

spicuous, though universally found in the eggs taken from urine.

Within the shell is a yolk membrane, with granules, surrounding

the embryo. According to this author the eggs will not hatch, so

THE DETERMINATION OF HUMAN ENTOZOA 121

Jong as Fetained in the urine, but rather perish if permanently kept

jn that fluid. The addition of water even, in small amounts, brings

about the opening of the egg. The enclosed embryo is exceedingly

variable in form, with an insignificant cephalic papilla, a coating of

cilia and the usual enclosed cell masses of the larval distome.

_ The eggs of the Cestoda, or tapeworms, are usually spherical,

oval or elliptical, although occasional species are characterized by

__ @ polyhedral form. In general they manifest great constancy,

_ although the outer membranes may be modified by shrinkage or

aspect of the egg may be changed by their absence, so as to

___ @gg is set free, is separated from the shell by a noticeable distance.

The embryo itself is small, usually spherical, and regularly armed

with six hooks arranged in three pairs near one pole. This six-

hooked oncosphere, as it is called, is borne in an inner membrane

of considerable thickness, and often prominent in appearance by

virtue of its structure, and to this the name of embryophore has

possess a thick brown shell, and a small lid, which becomes especially

distinct at the close of development. They contain a large amount

_ of yolk substance, and do not increase in size. As in all

_ Bothriocephalids the development is carried out in the water and

not in the maternal body, so that the inconspicuous egg cell is only

122 HENRY B. WARD

rarely to be found in the mass of yolk cells which usually com-

pletely conceal it.

In the large Japanese tapeworm, Diplogonoporus grandis, the egg

taken from the uterus possesses a deep brown shell (Fig. 15, Pl. IX)

according to the account of Ijima and Kurimoto (1894). The

shell is rather thick, the general form is oval, 0.063 mm. long and

0.048 to 0.050 mm. broad. The diameter of the operculum is 0.02

mm. and the contents of the shell consist of oil globules and a mass

of cleavage cells.

In Hymenolepis diminuta, according to Blanchard (1891, p. 46),

the egg is rounded or oval (Figs. 16, 17, Pl. IX). It measures from

0.060 to 0.070 or even 0.086 in diameter. The external membrane

is yellowish, delicate, and manifests indistinct striation, the median

membrane is doubled, the internal membrane or embryophore has

ordinarily two polar knobs, to which are attached no filaments, how-

ever. The onchosphere is elliptical and measures 0.036 by 0.028

mm. Its hooks are 0.011 mm. long.

Of Hymenolepis nana (v. Siebold) von Linstow (1896, p. 575)

says that according to his observations the eggs are in the rule

spherical, more rarely also oval ones are present. They show two

membranes, of which the external is delicate and irregular. The

inner is regular and sharply doubly contoured. This shows at

two opposed points an indistinct attachment from which a filiform

appendage proceeds that is three to four times as long as the egg.

Both these threads lie rolled up between the two egg membranes

and may simulate a median third membrane (Fig. 18, Pl. X). The

external membrane measures 0.039 mm., the internal 0.028 mm. in

diameter. The hooks of the onchosphere measure 0.0092 mm.; in

an especially elongated egg the external membrane was 0.043 mm.

long and 0.031 mm. broad, the inner 0.029 and 0.024 mm.

The eggs of Taenia saginata have been described by a number

of authors. The fullest comparison of the data thus obtained are

given by Leuckart (1886) whose work in the main is followed here.

These eggs are usually still covered by a thin yolk membrane, having

a diameter of about 0.07 mm., which is frequently drawn out at

two opposite points into long delicate projections, of which, however,

only a single one may be evident (Figs. 19, 20, Pl. X). In eggs

just formed in the uterus, which measures on the average 0.02 mm.,

the form is commonly oval, and the projections constant at the poles,

THE DETERMINATION OF HUMAN ENTOZOA 123

___ with a length about equal to the diameter to the egg. The em-

-__ bryophore is characterized by the considerable thickness or length of

the rods which compose it, and measures in diameter approximately

9.03 mm., in which connection one should notice that the form of

ne are oval then sebeieal The embryo itself

ae “Ie Taenia solium, Leuckart (1886, p. 667) says that the em-

a: ‘bryophore, like that of Taenia saginata is thick and firm, brown in

___ color, and covered with numerous rods, but more nearly spherical.

In diameter these eggs measure 0.03 mm., while the onchosphere

Measures not more than 0.02 mm. The embryophore is often the

only membrane present (Figs. 21, 22, Pl. X).

In Taenia confusa Ward, as described by Guyer (1898, p. 19),

____ the eggs are oval in form in the ripe proglottis. They posses on the

exterior a thin, transparent membrane, and within it a layer of little

gods, side by side. Next within this is a thin space, or layer, the

exact nature of which could not be determined. The elongated

inner portion is of about the same outline, as the external covering

of the egg, and is of different appearance in different specimens.

In some there is a dark cap-like structure at one end; in others at

both ends, and in still others along the side and one or both ends,

while the entire center is usually dark. In no case could the pyri-

form apparatus, or tail-like processes, mentioned by Leuckart for

the eggs of Taenia saginata, be determined. It is not unreasonable

___ to suppose however, that since they are very delicate, they may have

been present, but were destroyed through the poor preservation of

_ the material. These eggs measure in general 0.039 mm. long and

0.030 broad. They are of whitish or yellowish color (Fig. 24,

Pl. X).

In Taenia africana a new species recently described for the human

host in Africa, the eggs are described by von Linstow (1900, p. 491)

as very thick shelled. The shell is formed of a radially striated

_ membrane which appears on the exterior finely granulated. These

_ +—-€gRs measure 0.0312 to 0.0338 mm. in diameter. There are also

_ broad. The six hooks of the onchosphere are very distinct and

‘a Measure 0.0078 mm. in length (Fig. 23, Pl. X).

___ _ Two other species of cestodes, Dibothriocephalus cordatus and

_ Dipylidium caninum also have been reported from the human host.

124 HENRY B. WARD

In the former case the eggs are not wel: known, and in the latter

case they are cemented together in masses, which makes an individual

description of little value. One of the latter species, however, is

represented in Plate X (Fig. 25) after Diamare (1893). Much

the same holds true of Davainea madagascariensis, while Hy-

menolepis lanceolata is apparently an occasional parasite merely and

other forms definitely reported from man are in the larval condition

in that host. Moreover, in the determination of cestodes in gen-

eral the eggs are of secondary importance, since one will secure

additional evidence in the form of the occurrence in the feces of

single proglottids or groups of such which have been set free from

the parent chain.

Among the round worms, or Nematoda, the greatest differences

may be found in the character of the eggs. In a large number of

cases, especially in the group of the Filariae, the forms are viviparous,

and no eggs are known. Among such, however, as produce eggs,

one finds wide variety in the character of this structure. In the

one case it is thin shelled, and reduced it may be to a delicate mem-

brane, containing an already well developed embryo. At the other

extreme the shell is thick and impermeable, or surrounded by a

mammellated albumen coat, which gives the structure a very char-

acteristic appearance. In the case of the heavy shelled egg, de-

velopment has usually not proceeded far, and the formation of the

embryo takes place only at some time after the expulsion of the

egg. The thick shell is here evidently a means for protection and

nourishment of the embryo, a feature which is unnecessary in the case

of those eggs deposited when the embryo is almost ready to carry

on an independent existence. All differences between the two ex-

tremes may be found in different species. In addition to the

Filariae which have no egg, and the small free living Rhabdites

which are accidental parasites, several species of nematodes are so

infrequent that we know little with regard to conditions respecting

the egg. Such species are Gnathostoma siamense, Strongylus apri,

Physaloptera caucasica, and Ascaris maritima. The ovoviviparous

Trichinella spiralis may also be excepted from the list of those, the

eggs of which are under discussion. In one case at least nematode

eggs have been taken for coccidia (Cf. Braun, 1902, p. 68, footnote).

The eggs of Strongyloides stercoralis (Fig. 44, Pl. X1) have been

ih, THE DETERMINATION OF HUMAN ENTOZOA 125

i is desertion they are of elipcal shape, with thin ear pel

__ lowish shell, and granular contents, which were distinctly in cleavage.

‘They measured about 0.0675 by 0.0375 mm. He calls attention to

gece x sagan 4 coef ingly a

to to 0.034 mm. Fee Aha ate

) n stating that eggs are present at stools only with the greatest

_ farity, he gives good reasons for accepting the correctness of his

observation, and calls attention to the agreement with the meas-

urements of several other authors. At the same time he shows that

the eggs described could not have belonged to the sexual inter-

In the whipworm, Trichuris trichiura, the eggs (Figs. 37, 38,

Pl. XI) are easily recognized. They are ellipsoidal with a brown

___ heavy shell, which is apparently perforated at both poles, while the

__ @fifices are closed by transparent plugs. Such eggs occur in the

feces before cleavage has taken place and they measure 0.05 to 0.054

mm. in length by 0.023 in breadth.

_____ In Dioctophyme renale, a rare human parasite, the egg has been

= “well delineated by Balbiani whose figures (Figs. 26, 27, Pl. X) are

__ copied here after Railliet (1895). The original description is not

__In Strongylus subtilis Looss the ripe eggs (Fig. 43, Pl. XI) are

_ described by that author (Looss, 1895, p. 169) as of oval form with

a length of 0.063 mm. and a breadth of 0.041 mm. The shell is

very thin and the content strongly granular, so that the nucleus

_ cannot be recognized. At the same time Looss believes that cleav-

age does not take place in the interior of the female organs.

____ Investigating what is probably the same species in Japan, a year

later Ijima writes (1896, p. 160) that he has found a larger number

of eggs in the uterus, and that those which lay nearer the exit were

‘in the process of cleavage. He also discovers a few free eggs ex-

_ actly comparable to the uterine egg mentioned previously. These

‘measured 0.08 mm. in length and 0.035 to 0.04 mm. in breadth,

_ while the granular yolk was split into numerous cleavage spheres,

_ 005 to 0.01 mm. in diameter, forming a solid morula-like mass.

Yet at both ends of the egg there was a narrow unoccupied space

126 HENRY B. WARD

between this and the thin hyalin shell. Possibly this space explains

the greater length of the egg as given by Ijima in comparison with

the statements of Looss cited above.

In Uncinaria duodenalis, the eggs (Fig. 28, Pl. X) have been care-

fully investigated by Schulthess (1882, p. 215), who gives the fol-

lowing description: They reach maturity in the uterus, and are

possessed of a thin, doubly contoured shell, oval in form, although

one side is often flattened somewhat. He cites the following table

regarding the size of the egg according to different observers :

Length, mm. Breadth, mm,

PUCCORCIED ocine ss c0nsness caneeien eee 0.032

i errr rite ore 0.0319

OUR nnd on nes skda césneval bus ake eee 0.032-0.024

er ee ee lp 0.040-0.041

According to Schulthess’ own measurement the eggs vary from

0.0602 long by 0.0382 broad to 0.0674 long by 0.0359 broad, or

0.0602 long by 0.0449 broad. This author ventures also the remark

that his investigations do not support the supposed considerable vari-

ations in size, and that his own figures give the extreme values for

numerous measurements.

In the new American hook worm, Uncinaria americana Stiles, the

description given by that author (Stiles, 1902, p. 193) records the

size of the ova as 0.064 to 0.072 mm. long by 0.036 to 0.040 mm.

broad, ellipsoidal in outline, in some cases partially segmented in

the uterus, while in other cases they contain a fully developed em-

bryo when deposited. The egg possesses a very thin shell without

characteristic features (Figs. 29-32, Pl. X).

The eggs of the common round worm, Ascaris lumbricoides, are

usually easily recognized by their characteristic mammelation. They

present, however, certain variations which render confusion possible

in some cases, as in that recently described by Miura and Nishiuchi

(1902, p. 637), from whose account the following data are ex-

cerpted : The normal fertilized eggs are round to elliptical, with three-

fold thick shell, and mammellated albumen covering of yellowish

tone. The content of these fertilized eggs (Figs. 33, 34, Pl. XI)

is finely granular, and round in form, so that at both poles between

the content and the elongated shell one may distinguish a crescentic

ee a a a eee

THE DETERMINATION OF HUMAN ENTOZOA 127

space filled with-a clear fluid. In the center of the spherical mass

ey roreeatiy be distinguished 2s » clear space.

variations, which are apparently due to the low resisting power of

the shell, and to the irregular distribution of the albuminoid cover-

ing. The shell proper is doubly contoured, relatively thin, and with

= fertilized egg. Such eggs measure on the average of numerous

Measurements 0.081 in length by 0.045 mm. in breadth, varying from

_ diameter, which is closely in accord with figures given except by

_ French authors, who cite the length from 0.075 to 0.087 and the

___ ‘The egg of the related species Ascaris canis from the cat and dog,

_ also found occasionally in man, is represented (Fig. 36, Pl. XI)

after Braun (1902).

____ The eggs of Oxyuris vermicularis are rarely met with in the feces.

_ They are, however, of oval form, with very thin shell, measuring

_ 0.05 by 0.016 to 0.02 mm. When deposited they contain an already

__ and have carried their development to the formation of an embryo

_ im the body cavity of the female worm. In the case of Gigantorhyn-

_ thus gigas the eggs found in feces are with the three membranes,

__ 0f which the middle one is the thickest. The external measurements

s _of the entire mass vary 0.08 to 0.1 in length (Fig. 45, Pl. XI).

« _ It is necessary now to call attention to possible results of the

examination in the way of non-agreement of the forms discovered

[with the data at present known regarding human parasites. The

ee ae

_ to the world, and most frequently has resulted in the description of

ee ee oe ee ee wee ete

128 HENRY B. WARD

duly baptized. Unfortunately there are two other possibilities

which are more frequently met with than the one just cited, and a

disregard of them has led to great confusion. It may be in the

first place that the species is new to the human host, but is one

which is known from some other host. It consequently should not

receive a new name, but should be discussed merely in the light of

its occurrence under these conditions heretofore unknown.

Such a species may be normal to the human host as well as to that

from which it was previously known, but a considerable range of

cases must be brought forward in order to demonstrate this fact.

In the case of a normal human parasite this will not be difficult after

attention has once been drawn to its occurrence in a given region,

and a failure to find further evidence of the occurrence of a new

human parasite increases the probability that the form discoverd falls

into some other category always provided that the patient has not

been in some other locality, in which of course the parasite may

well have been acquired. Such cases throw an interesting side light

on the dispersal of human parasites. The determination of a single

case in a host of local habit inclines to the belief that it represents

an instance of occasional or accidental parasitism; and this brings

us to consider the possible types of parasitic existence.

One may recognize among human parasites those which occur in

their normal host but in an unusual location, like the brain cysticerci

or a liver fluke in a subcutaneous cyst and these may be spoken of as

erratic; there are also many of the species listed which can not be

regarded in any way as characteristic of the human host. Such

are the occasional parasites which are species of true parasitic habit

and can attain normal development in the human host but ordinarily

do not find conditions favorable for their introduction. As an in-

stance of such species may be mentioned Fasciola hepatica, the

common liver fluke of the sheep which in many regions of the world

is extraordinarily abundant. That it can thrive in the human sys-

tem is demonstrated by the score or more cases of its occurrence

there definitely recorded, but its infrequence is equal evidence of

a general immunity on the part of man, lacking in these particular

cases, or, of special features in its life history which make the infec-

tion of the human host difficult. That the latter is the probable

explanation may be inferred from the fact that the cercaria larva,

liberated from the intermediate host, encysts on plants and hence

THE DETERMINATION OF HUMAN ENTOZOA 129

I cace on he rare Cocclasinn esate cf Soromephc apri,

. BIE asinnn, tac coemogatnen tapemeten of both or of

‘, SEN isiat extaciacs chen Coot eater ateorsetl cobditicns;

thus, a fish nematoda, Ascaris clavata, was discovered once in the

ce tooth of a man. Here the position was probably accidental,

but in other cases it is the result of the action of the parasite itself.

So the “red spiders,” or “jigger” mites of the central states, bury

themselves in the skin of man although such a position is so clearly

_ abnormal that in fact it destroys the chance of further development

and costs the parasite its life. A small leech, Limnotis nilotica,

_ €ommon in the circum-mediterranean area, is often drawn into the

_ throat of men and other animals drinking at wayside pools. It

usually retains its position, causing serious difficulty, until removed

operative interference; hence it has become an occasional para-

site of man rather than as most leeches, a temporary parasite; or

__ one may regard it as falling in the next following group of accidental

parasites. This example shows most clearly the narrow and some-

artificial limits which separate these groups of parasites from

another. Of the mites also which have been reported a few

soci tea ace saagpensaes bladder and rectum, it is

to say whether they are occasional or accidental parasites

are also rarely forms which commonly occur free living,

ud are introduced into some organ in which condi-

such that they can thrive. They became thus accidental

a group difficult practically to distinguish from the last,

tal asites, and yet presenting somewhat different bio-

The recent discovery by Stiles and Frankland,

as others, of the vinegar eel, Anguillula aceti, as an apparently

colonizer of the bladder in a female patient illustrates the

under consideration. There is little doubt that this parasite

§ introduced through the use of vinegar in vaginal douch we

: colonization, possibly by virtue of the trace of

present in ‘the urine which furnished it with nourishment.

striking is the case of Scheiber who discovered Pelodera

130 HENRY B. WARD

pellio in the urine of a female patient in Hungary. This typical

slime inhabiting nematode gained entrance no doubt through the ap-

plication of mud poultices which are commonly employed by peasants

in that region. It should be noticed that such accidental parasites

are necessarily confined to those groups of animals which have free

living forms. Such are Protozoa, Nematoda, and perhaps Insecta

in the larval conditions, while Cestoda and Trematoda, which live

only as parasitic forms in some host, would become rather occasional

parasites of man should they stray into the human system in some

chance manner and find favorable conditions for existence.

Quite distinct from the types just considered are pseudo-parasites

which rank high in clinical importance. Among them one may

recognize several very distinct classes. First, those which are ac-

tually free living animals, introduced by accident, usually in food or

drink, into the human alimentary canal, and exciting there abnormal

conditions which induce their more or less immediate and forcible

expulsion. Thus Botkin found in the vomit of a Russian numbers

of a small nematode which he wrongly believed to be a human para-

site. In fact it lives normally in the onion and its introduction into

the stomach with this food excited the untoward symptoms noted.

Similarly, Blanchard records a case in which coleopterous larvae were

found in the vomit of a child.

That such may be the result of introducing a true parasite from

some other host is indicated by several cases like that of Ascaris

maritima which Leuckart described from a single specimen vomited

by a child in Greenland and which this author noted was very sim-

ilar to A. transfuga of the brown bear. In all probability it was

ingested with the viscera of some animal (seal?), though it may

have been a species which had strayed into this unusual host only

to make its appearance under the circumstances noted.

Of similar import are the cases of Gordius, the hair snake, which

have been reported from man. In the adult condition this is

normally a free living species but about a dozen specimens have been

taken from man after a supposed sojourn of from a few hours to

fourteen days. Some of these have been vomited and others passed

per anum. This form has often been passed off upon the physician

as a true parasite, and in one celebrated case at least as the Guinea

worm.

THE DETERMINATION OF HUMAN ENTOZOA 131

Im the-sattie way one may find the explanation for other isolated

"cases of parasitism, even when the parasite is reported to have been

‘a from the alimentary canal. Thus Cobbold reported that

larvae of Blaps mortisaga, the English churchyard beetle, were

found in fecal discharges and many authors have recorded the pres-

ence of dipterous larvae in the alimentary canal.

____ _‘The majority of such observers have inclined to regard the larvae

__ a§ temporary endoparasites and to consider that they have accom-

_ modated themselves to the conditions present in the human host.

The cases seem to show that these larvae live for some time in the

_ canal and they often appear to evoke serious or even fatal disturb-

en giant ply ast doubt for Calan-

_ druccio experimented extensively on two families to which many of

___ the supposed accidental parasites belong and found that the ingested

_ larvae were regularly and promptly evacuated dead or dying and in

mo case secured a footing in the canal.

Among the Myriopods about forty recorded cases of pseudopara-

_ sitism have been brought together and discussed by Blanchard. In

_ the large majority the animal was taken from the nasal fossae,

_ though in a smaller number it was actually obtained living from the

alimentary canal where it undoubtedly can exist for a brief time in

_ spite of the untoward environment. The ingestion of such forms is

_ purely accidental, the symptoms those of helminthiasis in general

__ and their stay at most very limited. They never show any evidence

_ of adaptation to the new environment.

____ In some such accidental fashion other forms are sometimes intro-

__ duced into various organs not connected with the alimentary system.

_ Thus Trouessart reported the occurrence of a species of detricolous

_ Sarcoptids in the human testicle where the mites formed an old

_ colony in a painless cystic tumor.

____ In contrast with the living animals of the types noted, the second

class of pseudoparasites includes a large number of other structures

_ which have been described as parasites. These may be considered

_ conveniently in a few groups, the first of which includes bodies

| which are parts of the so-called host animal itself. Thus fragments

| lentis, F. oculi-humani, etc.), the organisms of whooping cough are

"nothing more nor less than ciliated tracheal cells torn from the wall

_ and found in the sputum in distorted form, while groups of small

132 HENRY B. WARD

axillary and inguinal glands, hydatid moles, and Pacchionian bodies

from the arachnoid have been frequently put on record as hydatid

cysts.

Parts of substances used as food, both of plant and of animal

origin, which have not been destroyed by the action of digestive

juices are also among the pseudoparasites of man. The radulae of

the common limpet have been reported several times from stools; the

seeds of the mulberry were duly baptized as parasitic worms; and

plant vessels and other similar undigested structures of peculiar ap-

pearance appear periodically as new helminthes. That a differentia-

tion of such structures is not simple appears from the account given

by Stiles of the partially digested banana fibers which closely sim-

ulate minute tapeworms. Wynn has found a good facsimile of

tapeworms in blackened but undigested strips of cold slaw. Some

years ago Leuckart entrapped a group of research students in

helminthology with the pulp vesicles of an orange which were found

in a fecal examination.

In all of the cases considered above it should be kept in mind that

the animals or these other structures actually came from within the

human body. It is necessary that the investigators have absolute

evidence on this point, for there is another class of objects of which

this cannot be said, and these call for brief mention here.

In determining the nature of unusual forms reported from man

it should always be kept in mind that in the absence of positive

personal evidence, suspicion in cases of neurasthenia at least favors

the deceitful introduction of doubtful bodies. In many cases on

record such things as earthworms, chicken entrails, etc., have been

forcibly introduced into the rectum or vagina and have been sub-

sequently reported by the attending physician as undoubted human

entozoa of a remarkable character! Here as elsewhere the ap-

pearance of unusual structures should at once arouse the suspicion

of the physician and call forth a most searching examination of the

case in all its factors that any deceit be disclosed or that in event of

the discovery of some rare parasite all conditions connected with

its appearance be put on record for future use. Furthermore, it is

important to preserve the fullest data in regard to any substances —

associated with the supposed parasite as well as concerning the food —

of the patient, whether usual or unusual, since in this way some hint —

as to the introduction of the questionable body may be found.

THE DETERMINATION OF HUMAN ENTOZOA 133

+ Finally, it is important to direct attention to the wisdom of pre-

aie all material, whether new and doubtful or not, in considerable

quantities, and both of the eggs and embryos as well as the adults,

_ Of as many thereof as can be obtained. In case of doubt regarding

___ the identification of species, or possible question as to the source, it is

_ important that the material, or some portion of it, should be referred

__ to some expert helminthologist for examination and verification of

the result attained. It is always a pleasure to have the opportunity

Of examining such material, and to assist one’s colleagues in any

_ Way in connection with such studies. In most cases, in fact, and

_ especially such as deal with the occurrence of rare forms, or such

__a$ are new, it is desirable that such corroborative evidence should

__ be secured before publication, for in this way is often prevented the

‘Separately.

___._The large number of parasites in other animals which some un-

_ usual combination of circumstances may bring into the human sys-

_ tem makes it imperative also that any supposedly new species be

_ submitted to the judgment of a specialist before it is described as

_ such. Only in this way can the discoverer avoid adding to the

long list of synonyms which already burden the literature of this

ae Reference has also been made to the grosser errors in determining

‘ the character of objects discovered in microscopical examinations.

_ Some of these have been detected by virtue of evidence drawn from

134 HENRY B. WARD

world owes a long list of anomalous, inexplicable and often un-

thinkable occurrences listed in the chronicles of helminthology as

in other fields of science. Progress depends upon the elimination of

these errors and the substitution of more accurate methods.

BIBLIOGRAPHY

Bagriz, E.

1880. Ueber parasitire Himoptoé (Gregarinosis pulmonum). Central-

blatt f. d. med. Wiss., XVIIL, (39), pp. 721-722.

1883. Ueber einige neue Parasiten des Menschen. Berl. klin. Wochen-

schr., XX., pp. 234-238, figs. 1-3.

Biancuarp, R.

1891. Histoire zoologique et médicale des téniadés du genere Hymeno-

lepis Weinland. Bibliothéque Géneralé de Médecine, Paris.

Braun, M.

1902. Die thierischen Parasiten des Menschen. Dritte Auflage. Wurz-

burg.

Dramare, V.

1893. Il Genere Dipylidium Lt. Atti R. Accad. Scienze Napoli (2),

VL, no. 7, 31 pp. 3 pl.

Guyer, M. F. ‘

1898. On the Structure of Taenia confusa Ward. Zool. Jahrbiicher.,

Abt. Syst., Geogr. und Biol., XL, pp. 469-492, plate 28.

Iyrma, L

1887. Notes on Distoma endemicum Baelz. Journal of Science College,

Imperial University, Japan, L., 12 pp., plate vit.

1896. Stronglyus subtilis in Japan. Journal of Science College, Imperial

University, Japan, VL, pp. 157-161.

Iyrma, L, ann Kurtmoro, T.

1894. Ona New Human Tape-Worm (Bothriocephalus sp.). Journal of

the College of Science, Imperial University, Japan, VI., pp. 371-385,

PL. xvi

Katsurapa, F.

1900. Beitrag zur Kenntniss des Distomum spathulatum. Beitrage zur

pathol. Anat. und zur allg. Pathol, XXVIIL, pp. 479-505, Taf. xm.

1900a. Beitrag zur Kenntniss des Distomum Westermanii, Beitr. path.

Anat. und zur allg. Path. XXVIIL, pp. 506-523, Taf. x1v, xv.

THE DETERMINATION OF HUMAN ENTOZOA 135

rahe!

iss ,

ill . _—

e Tan, i

1881. Beitrag zur Kenntniss der Trematoden. Arch. f. mikr. Anat.

XIX, 529-578, Taf. xxvi.-xxvit.

_ s8Bp. Die Parasiten des Menschen und die von ihnen herrihrenden

_--——s Krrankheiten, 2 Aufl, L, 2 Abt, 4 Lief., pp. 97-440, figs. 61-191.

i ~ w8o4. Ibid, 5 Lief, p. 441-736.

Lan, 0 ys

1896. Uber Taenia (Hymenolepis) nana v. Sicbold und murina Duj.

Jenaische Zeitschrift, XXX., pp. 571-582.

1900. Taenia africana n. sp., cine neue Tania des Menschen aus Afrika.

Centralbl. Bakt. und Par., 1. Abt., XXVIIL, pp. 485-490.

Looss, A.

1894. Ueber den Bau von Distomum heterophyes vy. Sieb. und Distomum

1895. Strongylus subtilis n. sp., ein bisher unbekannter Parasit des

Menschen in Egypten. Centr. Bakt. u. Par., I. Abt., XVIIL, pp. 161-

< 169. 1 pl.

} $896. Recherches sur la faune parasitaire de I'Egypte. Mém. Inst.

—- Egyptien, III. 252 pp., 16 pl.

1899. Weitere Beitrage zur Kenntniss der Trematoden-Fauna Aegyptens.

= Zool. Jahr., Syst., XII, pp. 521-784, Pl. 24-32.

Miura, K, ann Nisurucut, N.

-3go2. Ueber befruchtete und unbefruchtete Ascaridencier im mensch-

a lichen Kote. Centr. Bakt. u. Par., XXXIL, Orig., 637-641.

—- Opmwex, Tx.

“gs 1902. Fasciolopsis Buski (Lank.) [= Distomum crassum Cobb.], cin

bisher wenig bekannter Parasit des Menschen in Ostasien. Centr.

7 Bakt. u. Par., XXXL, Orig., pp. 573-581, 1 pl.

_ Panowa, C., ann Grassi, B.

= 1878. Sullo svilluppo dell’ Anchilostoma duodenale, Atti Soc. Ital. Sci.

Be , Nat., XXL, 6 pp. 1 pl.

‘ Ramu, A.

a 1893-1895. Traité de zoologie médicale et agricole, 2°. Ed. Paris.

Scmauinstann, H.

1886. Die embryomale Entwicklung der Bothriocephalen. Jenaische

j Zeitschrift, XIX., 520-572, 3 pl.

u | Somvurnes, W.

a 1882. Beitrige cur Anatomie von Ankylostoma duodenale (Dubini)

= Dochmius duodenalis (Lkt.). Zeit. £. wiss Zool, XXXVIL, 163-

220, 2 pis.

136 HENRY B. WARD

Sommer, F.

1880. Die Anatomie des Leberegels, Distomum hepaticum L. Zeit. £.

wiss. Zool., XXXIV., 104 pp., 7 pls.

Srizes, C. W.

1894-1895. The Anatomy of the large American Fluke (Fasciola magna).

Jour. Comp. Med. and Vet. Archives, Mar., 1894-May, 1895.

Stes, C. W. anp Hassatt, A.

1900. Notes on Parasites 51. The Lung Fluke (Paragonimus Wester-

manii) in Swine and its relation to Parasitic Haemoptysis in Man.

Sixteenth Annual Report, Bureau of Animal Industry, U. S. Depart-

met of Agriculture, pp. 560-611, figs. 24-28 in text. Pls. xxmi-xxv.

1902. The Significance of the Recent American Cases of Hookworm

Disease (Uncinariasis, or Anchylostomiasis) in Man. Ann. Rept.

Bureau An. Indust., XVIIL, 183-222.

Tuayer, W. S.

1901. On the Occurrence of Strongyloides intestinalis in the United

States. Jour. Exp. Med., VL. 75-105, 1 pl.

Tuomas, J. J.

1899. A Case of Bone Formation in the Human Brain due to the pres-

ence of Coccidium oviforme. Jour. Bost. Soc. Med. Sci., IIL, 167-9.

Warp, Henry B.

1894. On the presence of Distoma Westermannii in the United States.

Vet. Mag., L, pp. 355-359.

Yamaciwa, K.

1890. Beitrage zur Aetiologie der Jackson’schen Epilepsie. Arch. f. Path.

Anat. u. Phys. u. f. Klin. Med, CXIX. (2), 447-460, Taf. x1, figs.

I-3.

O6erewBewe, repr Heqiey Zpervosveyy OTH i syoeg 006!'PEUNSIE}4 vEgI'PeM ogelzi9eg

PLATE VIII

er eee En 2) a eee ee a

PLATE 1X

sro

THE DETERMINATION OF HUMAN ENTOZOA 137

eae EXPLANATION OF PLATES

s All off the figures have been reduced to the same scale in copying and the

Composite outline of the egg of Paragonimus Westermanii ac-

authorities. The host is indicated above each outline; the

observation.

Paragonimus Westermanii from sputum of man. After

507.

Dicrocoelium lanceatum in surface view. After Braun,

At i

int

ggaaaa|

ee FER

of Opisthorchis sinensis. After Ijima, 1887, pl. 7, fig. 3.

of Opisthorchis sinensis. After Katsurada, 1900, pl. 13, fig. 8

of Opisthorchis felineus. After Braum, 1902, p. 158

of Heterophyes heterophyes. After Looss, 1896, pl. V., fig. 39.

Sree,

Plate IX

Egg of Schistosoma haematobium from the urine of man. After

XL, fig. 112.

of Fasciola magna. After Stiles, 1894, p. 227, fig. 4. This

the minimum, not to the average size of ova in this species.

of Fasciola hepatica. After Sommer, 1880, pl. VI., fig. 1c.

Egg of Dibothriocephalus latus with operculum opening. After

Schauinsland, 1886, pl. VIL, fig. 31.

The same, earlier stage. After Schavinsland, 1886, pl. VIL,

1s Egg of Diplogonoporus grandis taken from the uterus. After

Kurimoto, 1894, pl. XVIIL, fig. 9.

Egg of Hymenolepis diminuta. After Blanchard, 1891, p. 45.

The same, clongated form.

= ¢

zalgealgetela

sake § eager es

138 HENRY B. WARD

Plate X

Fig. 1% Egg of Hymenolepis nana. After von Linstow, 1896, p. 580,

fig. IV.

Fig. 19. Mature egg of Taenia saginata, After Leuckart, 1886, p. 568.

Fig. 20. The same without external membrane. From human feces.

After Leuckart, 1886, p. 186.

Fig. 21. Egg of Taenia solium. After Leuckart, 1886, p. 667.

Fig. 22. The same without external membrane. From human feces.

After Leuckart, 1886, p. 186.

Fig. 23. Egg of Taenia africana. After von Linstow, 1900, p. 489.

Fig. 24. Egg of Taenia confusa. After Guyer, 1898, pl. XXVIIL, fig. 11.

Fig. 25. Egg of Dipylidium caninum. After Diamare, 1893, pl. L, fig. 18.

Fig. 26. Egg of Dioctophyme renale in surface view. After Balbiani

from Railliet, 1893, p. 421.

Fig. 27. The same in optical section.

Fig. 28. Egg of Uncinaria duodenalis. After Parona and Grassi, 1878,

pl. IL, fig. 6. ;

Fig. 29. Egg of Uncinaria americana from human feces. After Stiles,

1902, Pp. 193.

Figs. 30-32. Same with cleavage begun.

Plate XI

Fig. 33. Egg of Ascaris lumbricoides from human feces. Seen in surface

aspect. After Stiles, 1902, p. 202.

Fig. 34. Same in optical section.

Fig. 35. Unfertilized egg of Ascaris lumbricoides from human feces.

After Miura and Nishiuchi, 1902, p. 638.

Fig. 36. Egg of Ascaris canis. After Braun, 1902, p. 303.

Fig. 37. Egg of Trichuris trichiura from uterus of female worm. After

Leuckart from Stiles, 1902, p. 202.

Fig. 38 Same in stage from human feces.

Figs. 39-41. Eggs of Oxyuris vermicularis taken from uterus of female

worm. After Leuckart from Stiles, 1902, p. 202.

Fig. 42. Same in stage found in human feces.

Fig. 43. Outline of egg of Strongylus subtilis. The larger oval and the

cleavage cells from eggs free in stomach contents, after Ijima, 1896, p. 160;

the smaller oval from eggs before deposition after Looss, 1895, p. 169.

Fig. 44. Egg of Strongyloides stercoralis from human feces. After

Thayer, 1901, pl. IX., fig. A.

Fig. 45. Egg of Gigantorhynchus gigas. After Leuckart from Braun,

1902, Pp. 309.

ae oe

_ THE NORTH AMERICAN SPECIES OF LIMNESIA

By ROBERT H. WOLCOTT

WITH TWO PLATES

I, INTRODUCTION

SUIT dick ‘semitone in species the genus Limassia to quite

| sively td nd sot aay met wi in clon

are cage gp i yma pal agiiesagh Flame Pagan Sar

ens etal segment; and by the characters of epimera

ae area. The individuals are active and brightly-colored,

mot only all other weaker forms of animal life present with it in

_-_-—s@m aquarium falling prey to its rapacity, but also most other mites,

especially those of small size and with soft bodies.

______The characters common to representatives of the genus may be

+ mumerated more in detail as follows:

nae

Hie

tendency to dorsal pitting.

Body usually soft and epidermis marked with fine, wavy lines;

sometimes a tendency to become papillose is observed, and in cer-

tain species a chitinous covering composed of a fine meshwork is

developed. The glands are prominent, though not specially num-

_ @fous, and surrounding each is a small chitinous ring bearing a

| fine hair.

The two eyes on cither side, usually fused in adult hydrachnids,

@ spherical lens and an elongated pigment body, and is movable; the

140 ROBERT H. WOLCOTT

posterior smaller and not movable. Below the eyes on the anterior

surface of the body is a pair of antenniform bristles.

The maxillary organ is produced into a short snout at the end

of which is the mouth opening, on the dorsal margin of this open-

ing there being two hairs and on the ventral two more. The maxil-

lary shield appears crowded between the anterior pair of epimera,

while posteriorly on either side a short, broad ancoral process ex-

tends outward beneath these epimera.

The palpi vary considerably in different species, but in all the

second segment is the stoutest, the fourth is longest and relatively

slender, and the fifth quite pointed, the claws at its tip being small

and inconspicuous. In most species there is, on the flexor surface

of seg. 2 a prominent peg-like spine, usually inserted into the end

of a projecting papilla, while toward the tip of seg. 4 on the flexor

surface is a pair of fine long hairs borne on low papillae placed at

the proximal end of an excavation varying in depth. In many

species the spines on the palpi are pectinate.

The epimera are in four groups, the two anterior and the two

posterior on either side being in apposition. The space between

ep. II and ep. III is narrow, somewhat broader toward the lateral

end where a gland opens. Ep. III is of the usual form, but ep. IV

is characterized by its large size and triangular outline. Of the

sides of this triangle the longest is lateral, the next in length is

medio-posterior, and the shortest in medio-anterior, meeting ep.

III. Leg IV is inserted at the posterior angle of this epimeron.

The gland usually situated behind this last epimeron is here situated

at its medial angle and is surrounded by a chitinous plate of con-

siderable size which is set in between ep. III and ep. IV at the

medial end of the suture separating them and which varies in dif-

ferent species in regard to its exact position with respect to the two

epimera and to the degree to which it is fused with them.

The legs bear numerous spines, many of them, especially at the

distal ends of the segments, being pectinate. Swimming-hairs

are present on III and IV. The anterior three pairs are terminated

by retractile claws, which are curved, sharply pointed, and bear, in

addition to the principal tip, two others, one internal, the other

external. The last segment of leg IV ends in a point bearing no

claw but furnished with a long, slender spine inserted close to the

tip.

NORTH AMERICAN SPECIES OF LIMNESIA 141

_ The genital area is included in the space lying between the

diverging medio-posterior margins of the last pair of epimera, and

exhibits as a whole a more or less broadly and more or less regularly

pyriform outline, the broader end being posteriad. The cleft is

ke aie i ae

three or four acetabula, and numerous spines, irregularly dis-

The male is smaller than the female and the appendages are

The spaces between the epimera are narrower.

__ The most marked difference appears, however, in the genital area,

_ which in the male is shorter and broader. The two genital plates

____ Show a tendency to fuse at their ends, forming a continuous plate

about the cleft, and correllated with this is a change in the form

of these plates; in the female the inner margins are straight and

the plates of the two sides come together over the cleft, but in the

male these inner margins are excavated, leaving a narrowly ellipti-

cal space about the cleft filled by its swollen lips. In front of the

_ two flaps appears, in the female, a transversely-placed, narrow,

____ Although there are certain species of Limnesia which may be at

____— once recognized by some striking character, such as the chitinous

covering of L. lorea Thor and L. cornuta, here described, the in-

creased number of acetabula of L. aspera Koenike, a Madagascar

species, and the very peculiar two-clawed hooks projecting from the

anterior end of the genital plates of L. armata Koenike, an African

form, other species of the genus are less easily recognized and the

author has found it at times difficult to discriminate between them.

the species: character of integument, form of palpi and character

spines and hairs, form of antenniform bristles, details in form

s epimera, character of spines on the legs, and characters of the

____ genital area. The characters seem to be fairly constant for each

___ Species, though there is some variation in the length of the papilla

_ son palp. seg. 2, in the number of swimming-hairs, the distance be-

____ tween the acetabula, etc. In every case where specimens have been

___ referred to a European species the author has found details in which

____ his specimens do not entirely agree with printed descriptions, but

our knowledge of variation in this group is not sufficiently accurate

142 ROBERT H. WOLCOTT

yet, in the author’s opinion, to furnish a satisfactory basis for the

recognition of subspecies, varieties, or forms.

The genus possesses a wide distribution, species having been

described from Europe, eastern Africa, Madagascar, South America,

and Central and North America. Piersig (1901) recognizes twelve

species and two have since been described, while Piersig also

enumerates fourteen the status of which is uncertain. Of these

three recognizable species and three questionable ones are referred

to North and Central America.

Stoll, in the Biologia Centrali-Americana (87), described four

species from Guatemala—L. guatemalteca (p. 13, 47, Pl. VII, f. 2),

L. longipalpis (p. 13, 47, Pl. IX, f. 2), L. puteorum (p. 14, 48, Pl.

VII, f. 3), and L. laeta (p. 14, 48, Pl. VIII, f. 2). Of these the

first is a nymph; the second is a form allied to L. histrionica, but the

name cannot stand as it had previously been applied by Koch to a

European nymph. L. puteorum is most closely related to L. connata

Koenike, a European species, coming among those forms in which

the spine on the second palpal segment is not borne on a papilla.

L. laeta is a species characterized especially by the absence of this

spine on the flexor surface of pal. seg. 2, and also by the peculiar

form of the genital area which is greatly broadened transversely and

of an irregular outline.

Koenike (956) discovered two species in material collected in

Canada by Dr. J. B. Tyrrell, L. undulata (Mill) and L. Koeniket

Piersig, the two being well-known European forms.

To these species hitherto recorded from North America the author

now has the pleasure of adding five, of which two are new, and the

list, together with the known distribution, becomes as follows:

1. Limnesia laeta Stoll—Guatemala.

2. Limnesia cornuta n. sp.—Michigan.

3. Limnesia histrionica (Herm.)—New Jersey, Michigan, Wis-

consin, Illinois, Nebraska, Washington.

4. Limnesia undulata (Miill.)—New York, Michigan, Canada.

5. Limnesia sp. (longipalpis Stoll) —Guatemala.

6. Limnesia paucispina n. sp—Michigan.

7. Limnesia puteorum Stoll (!)—Mexico, Guatemala.

8. Limnesia Koenikei Piersig—Canada.

9. Limnesia maculata (Miill.)\—New York, Michigan.

NORTH AMERICAN SPECIES OF LIMNESIA 143

In the preparation of this paper the writer has had not only the

aterial collected by himself but also specimens received from Mr.

. W. Berry of Passaic, N. J., Mr. R. H. Johnson, until recently

eee ret Combriden, Bees. Mz. J. B. Shearer of Bay

ty, Mich., Professor J. G. Needham of Lake Forest, IIL,

en Sete ee Oe A. Dugés

ieee scogcenepcrinenn of 1. bewioniea, L. undulata, L.

and L. Koenikei.

Sts scree cn chs corp, ont to coos oa

I ge ee es we ce Ge erdiewt geatien

of the segment. The dorso-ventral diameter of a palpal segment

No attempt has been made, in the paper, to deal with immature

Il. DESCRIPTIONS OF SPECIES

1. Limnesia cornuta n. sp.

____ A Species which may be recognized at once by the presence of a

_ chitinous meshwork covering the body, by the length of the antenni-

_ form bristles, and by a plate on the dorsal surface of the body

posteriorly.

___ The body is broad, evenly rounded anteriorly, truncate posteriorly

and moderately high, with an evenly arched dorsal surface. The

___ measurements of two female specimens are 0.95 mm. by 0.87 mm.,

7 eos mm. by 089 mm. respectively, while a male is 0.71 mm.

a om broad.

144 ROBERT H. WOLCOTT

The integument is distinguished by the presence of a chitinous

meshwork made up of narrow trabeculae separating i ;

polygonal areas from 3 # to 4 m in diameter (PI. XII, fig. 3). The

glands scattered here and there are rather prominent, and there is

a pair of long slender hairs borne on papillae, about 0.2 mm. apart,

situated between and slightly in front of the eyes. Posteriorly on

the dorsal surface is an elliptical area about 0.15 mm. by 0.12 mm.

which shows prominently as a dark patch in a fresh specimen, and

which seems to mark the position of certain glands beneath the sur-

face. It apparently corresponds to the plate described by Koenike

(98): 402) as present in L. scutellata, and in a mounted specimen is

seen to be a clearly defined plate with heavier trabeculae and much

finer meshes than over the rest of the body.

There is a space of about 0.25 mm. between the eyes of the two

sides while those of the same side are separated by a distance equal

to twice the diameter of the lens of the anterior, which is rather

small, measuring only 24 yz. The finely serrate antenniform bristles

(Pl. XII, fig. 2) are long, stout, and curved backward, standing

nearly vertical on the papillae which bear them. In one female the

length of these bristles is 64 m, in a male 87 4, while the distances

separating the two are 0.13 mm. and 0.10 mm. respectively.

Corresponding to the deposition of chitin in the integument all

hard parts are very heavily chitinized.

In length the palpi of the male exceeds by considerable half the

length of the body, while in the female (PI. XII, fig. 1) they fall

a little short of the same measure; in width they are about equal

to the first pair of legs. The spine on the flexor surface of seg. 2

is excavated toward the distal end, the two papillae in this excavation

both equalling less than one-fourth the dorso-ventral diameter of

the segment. Seg. 3 is in this direction nearly as broad as seg. 2;

on its inner side near the extensor margin is a longer distal and

a shorter proximal spine, while at the distal margin of the segment

on the outer side is a pectinate spine between the other two in length.

Seg. 2 has three spines on the inner side and two on the outer. Seg.

4 has a straight flexor margin for about two-thirds its length, then

is excavated toward the distal end, the two papillae in this excava-

tion bearing long, slender hairs; on the inner side at this end of the

segment are a few very small hairs. The proportionate length of

the palpal segments is as follows: 5, 27, 19, 38, II.

NORTH AMERICAN SPECIES OF LIMNESIA 145

‘The maxillary shield is triangular and extends back between the

_ anterior pair of epimera nearly to their posterior extremities, where

_ they are separated by a distance equal to a little less than their

a. The spaces between epimera are relatively nar-

Rte cs caee, Ran thas the coe

‘5 tal area, while in the female it lies behind the middle acetabula.

_ The gland plate at the inner end of ep. III occupies much of the

__ end of the epimeron.

-_ The legs are of moderate length, increasing in length from the

_ first to the last pair, and only the last pair distinctly longer than the

_ body. Spines are not numerous, but are stout and very many are

_ pectinate, especially on legs III and IV. Swimming-hairs are few,

_ there being only four on III 5 and four or five on IV 5.

____ The genital area in a female (PI. XII, fig 4) 0.98 mm. long meas-

ow in length by 0.16 mm. in width; in a mounted male

. 5) it is 0.18 mm. long by 0.21 wide. In both sexes

in shape and resembles that of L. Koenikei, the

breadth being about two-thirds the way back from the

rior end. The acetabula are large, elliptical in form, of the

I] number, and while in the male the distance between them is

same and a little less than one-third the length of one

the female the second and third are close togther and the

second are separated by a space not over one-half the

Mate Femate

mm, am,

Reeth che dikes Gash Gen dake dns ubdlaousle « 0.70 (estim.) a95

Denuthuhaek candi ede Caadeadnatecscahe sens 0.63 (estim.) o87

- O$5 0.59

MRHOG C6 6560006 whe cous cb cbbesiddededdececces 0.66 072

DRAG DUS ese covecsccceesccosetcsboodbesdverodces 0.75 0.85

+ O98 bog

DET thbin ccb cst shebacsdabioossiabdebde chess 0.43 O44

SE UOOR acinavesenqncpatpacednncestvecce GOS 0.20

i a Cn ask sb bwatines atanes poaedeeec oat o18

El iRseclor of the specimen from Charlevoix is stated in field notes to

have been whitish, varied with dark; a red spot near the posterior

146 ROBERT H. WOLCOTT

end of the body; eyes carmine-red, and legs and epimera tinged

with the same. The others were all similar.

Types in the author’s collection.

Of this species one female specimen was collected in Round Lake,

Charlevoix, Mich., in bottom towing, July 10, 1894; a second

female was secured in dredging on the bottom in 16 meters of water,

in Lake Michigan, two miles northwest of Norwood, Mich., August

8, 1894; two males and a young female were taken in Softwater

Lake, near Grand Rapids, Mich., August 19, 1895.

The name is in allusion to the appearance produced by the long

antenniform bristles. This species is closely related to L. lorea

Thor (99: 23), and in fact agrees with every detail in his brief

description. He makes no mention, however, of the conspicuous

posterior dorsal plate or of the prominent antenniform bristles, and

his figures (Pl. VIII, figs. 86a, 86b, 87) show the following points

of difference: The papilla and spine on the flexor side of palp. seg.

2 are longer in L. lorea than in L. cornuta; the other spines on the

palpus are more numerous in L. lorea; the space between the anterior

two acetabula is much wider in Thor’s species and the acetabula are

circular instead of elliptical; the space between the anterior epimera

is wider and between the posterior narrower than in L. cornuta.

The two are evidently closely allied but apparently distinct. L.

cornuta resembles L. scutellata Koenike, from Madagascar, in the

size of the antenniform bristles and in the possession of the dorsal

plate, but differs in very many other details of structure.

2. Limnesia histrionica (Hermann)

Hydrachna histrionica Hermann, 04; 55, pl. II, fig. 2.

Limnesia fulgida Koch, 35; fasc. 2, fig. 19.

Limnesia maculata Krendowsky, 84; 304, pl. VII, figs. 4, 7, 8.

Limnesia longipalpis Soar, 97; 23, pl. III, figs. 6-9.

This well-known European species can be recognized by the

faintness of the lines on its surface, the small size of its antenniform

bristles, the length and thickness of its palpi, the length of the papilla

on palp. seg. 2, and the character of the genital area.

It is one of the largest species of the genus, female specimens

being commonly met with of lengths varying from 1.75 mm. to

2 mm. and breadths from 1.50 mm. to 1.70 mm., while the males —

NORTH AMERICAN SPECIES OF LIMNESIA 147

rin in length from 1 mm. to 1.25 mm. The body is broadly

al in dorsal view and highly arched in lateral view, but not evenly

, there being more or less well-developed anterior and posterior

dorsal depressions ; evenly rounded at both ends, sometimes slightly

emarginate laterally behind the eyes.

‘The surface of the body is marked by very faint wavy lines which

The eyes are relatively very small, in a female example selected

random and 1.90 mm. long by 1.59 mm. broad, the anterior lens

ing only 32 w in diameter. In the same specimen the distance

_ between the anterior eyes of opposite sides is 0.48 mm. and the

_ distance between the posterior 0.57 mm., while the two eyes on

_ ¢ither side are 0.14 mm. apart. The antenniform bristles are very

small, pointed, and borne on inconspicuous papillae; in the speci-

_ men just referred to they are about 24 long.

_____ The palpi (Pi. XII, fig. 6) are long, those of the female in length

walf that of the body, while those of the male may be two-thirds

See body length ; they are about twice as wide as the first pair of

_ The proportionate length of individual segments is: 4, 26,

_ aearas. Seg. 3 is nearly as thick as seg. 2, tapering toward its

_ distal end, while seg. 4, is not only proportionately long but also

its thickness at the middle being only one-eighth

length and only two-sevenths the thickness of seg. 2. The

: ee and though the

_ peg-like spine at its tip is very short, the length of the two combined

_ equals nearly half the thickness of the segment; the sides of the

_ papilla are nearly parallel. On the inner side of seg. 2, toward the

_ dorsal margin, is a row of about seven small spines, on the opposite

_ side a row of three toward the proximal end and two, side by side,

_ at the distal margin; on the inner side of seg. 3 are three spines and

The maxillary shield is broad, relatively large, and extending

well back, nearly even with the posterior ends of epp. I, which send

Tow processes inward behind it, the processes from opposite

} meeting and fusing in the median line (Pl. XII, fig. 7). The

ses between the epimera are relatively wide. The medio-pos-

148 ROBERT H. WOLCOTT

terior margins of epp. IV are widely divergent, forming an angle

125° to 130°; anteriorly these margins are concave, posteriorly

convex. The inner ends of epp. III and IV are produced, and the

gland plate is set in opposite the inner end of the suture between

them. The suture between this plate and ep. III is obliterated.

The legs are rather slender and leg II is nearly as long as leg III.

In the case of the male these two legs approach the body-length

and leg IV exceeds it by considerable, but in the female leg IV

hardly equals this length. The distal segment in each leg is slightly

curved. Hairs and spines are very numerous, relatively long,

rather slender, and comparatively few are pectinate. On segs. III 4

and III 5 are five and eight to ten swimming-hairs respectively; on

segs. IV 4 and IV 5 six and ten.

The genital area is so placed that a line connecting the posterior

angles of epp. IV will in the female pass between the two anterior

acetabula, in the male through the posterior. It is typical in form

with rather large acetabula, of which the two anterior are in the

female approximately circular, the posterior elliptical in outline,

while in the male all are in general circular. The former are separated

in the female (Pl. XII, fig. 7) by a space equal to half the diameter

of each, while the posterior are closer together, and in the male the

same is true. In the male, however, the whole area is slightly

broader than long, while in the female it is about one-seventh

longer than broad, being in one specimen, for example, 0.22 mm.

wide and 0.25 long.

MEASUREMENTS

Mate Mare Femace

Lake St. Clair High Id. Harbor High Id, Harbor

mm, mm, mm,

Lapath of ROGy «caps disse vicscs dvcndashe 1.24 1.90

Width 08 ROG oss ewan kden scovds tanks 1.00 1.59

TAG FT ccticcdbbuedeavn Mieresscceednen®s 1.17 1.04

Lag Hil wcscees secs vtdeeond: nemeeaeehe 1.39 1.16 1.35

Lae TV i sinceskscicdkbackans eee 1.81 182 —

Pala: 6.5 is on 040 at Suadaessmabasiaeee 0.79 0.96

Length of genital area..............+4- 0.21 0.26

Width of genital area...............+.- 0.22

The color varies greatly. Specimens from Reed’s Lake, Grand —

Rapids, Mich., were “yellowish-white, tinged with greenish an- —

NORTH AMERICAN SPECIES OF LIMNESIA 149

riorl) between the bright red eyes; brownish-black patches and

_yermillion spots dorsally; below a clear white patch posteriorly ;

legs, palpi, etc., bright bluish green.” Others from Twin Lakes,

harlevoix, Mich., were described in field-notes as “orange-red

_ throughout, appendages paler; darker shadings; eyes purplish-

brown.” Specimens from Lake St. Clair were “yellowish-brown,

whole surface with very fine whitish lines; spots of yellow, and two

! € patches on either side dorsally ; legs bluish green.”

_ Judging by previous experience this is the most common North

species of Limnesia, and an abundance of material is at

_ The following localities are represented :

New Jersey—Passaic, April, 1902, 1 female (E. W. Berry).

a - Michigan—Lake St. Clair, summer of 1893, 114 specimens,

q " equally divided between males and females; Reeds’s, Lamberton, and

_ Softwater Lakes, and Grand River, Grand Rapids, summers of

"1895, 1896, 1897, and 1898, 12 males and 7 females; Twin Lakes

and Susan Lake, Charlevoix, August, 1894, 2 females; High

_ Island Harbor, Northern Lake Michigan, August 18, 1894, 46 males

and 16 females.

Wisconsin—Lake Winnebago, Oshkosh, August, 1897, 3 females.

peeie—Pond at Galesburg, September, 1895, 5 males and 2

_ Nebraska—Pond at Child’s Point, Omaha, May, 1902, 2 males.

we March 10, 1902, 2 females (Trevor Kin-

aid). A total of 211 adult specimens.

_ This is a generally distributed European species, being recorded

by Piersig (1901: 174) from Finland, southern Russia, Sweden.

——— Austria, Switzerland, France, England, and

3. Limnesia undulata (Miller)

” Hydrachna undulata Miller, 1781 ; 80, pl. XI, fig. 1.

__ Hydrachna erythrophthalma Hermann, 04; 57, pl. II, fig. 3.

—— Limnesia pardina Neuman, 70; 109. Neuman, 80; tor, pl. I,

34, 3b, 3¢, 34.

2 variegata Lebert, 79; 344-

a tiasio tesselote Lebert, 79; 349, pl. XI, fig. 2.

__ Limnesia triangularis Lebert, 79; 352, pl. XI, fig. 3.

ene ceesforects Leber, 795 355, pl. XI, fig. 4.

150 _ ROBERT H. WOLCOTT

Limnesia calcarea Koenike, 81; 622.

Limnesia tigrina Krendowsky, 85; 303, pl. VII, figs. 5, 6.

Limnesia undulata Koenike, 956; 206, pl. Il, fig. 48 (from

Canada).

This species is very similar to the preceding, but can be told from

it by the longer palpi, the smaller acetabula and the greater distance

between the two anterior, as well as by other details of structure

which will appear in the following description. It can best be

described by comparing it directly with L. histrionica.

The form of body is similar to that of L. histrionica but, while

a few specimens have been taken approaching in size the the largest

of that species, the average of those in the author’s collection is

distinctly smaller. The lines on the surface are more evident.

The eyes are larger and the anterior lens is elongated. In a

female specimen 1.17 mm. long and 1 mm. wide the anterior lenses

are 53 u long by 34 » wide and are 0.33 mm. apart, while the pos-

terior are situated closer to them than in the other form and slightly

farther outside them. The antenniform bristles are here also small,

slender and pointed, but are slightly longer; in the specimen just

referred to the distance between them is 0.24 mm.

The palpi (Pl. XIII, fig. 9) are longer than in L. histrionica,

nearly equalling the body-length, and not so thick, though nearly

double in width the first pair of legs. They are relatively more

slender, especially the fourth segment, which at its middle has a

thickness less than one-ninth its length and one-third the thickness _

of seg. 2. The proportional length of the individual segments is

3, 25, 16, 44, 12. Seg. 3 is nearly the same thickness throughout

and the flexor margin is very concave. On examining a number

of specimens of both species, the length of the papillae on seg. 2 is

found to vary considerably, but on the average that of L. undulata

is relatively shorter than that of L. histrionica and usually does not

equal more than one-third the thickness of the segment; it seems

to be inclined more anteriorly than in the other species. The spines

on segs. 2 and 3 are similar in number and position, though more

noticeably pectinate, but the excavation at the distal end of seg. —

4 is longer and the hair-bearing papillae are carried farther away —

from the tip.

The medio-posterior margins of epp. IV are less widely divergent. —

The spaces between all epimera are less wide.

NORTH AMERICAN SPECIES OF LIMNESIA 1st

pong somewhat stouter, with heavier spines,

more of these, especially on legs III and IV are prominently

Leg III is shorter than leg II in all specimens examined,

Piersig states that the contrary is true in the European

.. undulata, 111 4 has five to seven swimming-hairs, III 5, eight

and the corresponding segments of leg IV about the same

_ anphap ag lingers do foaeteaees

_ ‘post angles will in both sexes pass behind the whole area; in

one female specimen its length is 0.25 mm. and its width only 0.17

mm. The acetabula are nearly circular, relatively smaller and more

separated. Between the two anterior of the female (PI.

Sep equal to from one and a half to even two

MEASUREMENTS Mace Femae

mm, mm,

of body - approx.) 0.75 1.19

1 of body -- (approx.) 0.60 1.02

Leg I....-- ivddépcvaniweenitendiben hac conéecs ce-ccee GM 1.01

LCi acs on vb cans aPibgs ee gesccteus cde ck cose 0.97 1.20

GGL Lic Ci adesbnc dp eeeeb daveadeddscosesdeses 1.27 1.56

ite a os ian ty ba Madinneh ede tasks bance dads 0.77 1.01

SME MRTUREE BEER. 2055 050 cc ccc cccccccccccccecccccess 0.15 0.25

‘= ME St ae nn nee cdenecerseececncncnenstcee 0.17 0.17

__‘The color of specimens taken at Lake St. Clair, Mich., was

a Te eisderhiee with dark patches and a white transverse band;

eyes red; legs pale green.” Specimens from Saginaw Bay, Mich.,

_ show indications of having been of a red color.

_ ____ Specimens are at hand from Lake Chautauqua, N. Y., August,

1897, one male (R. H. Johnson) ; from Lake St. Clair, Mich., sum-

__mer of 1893, 4 males, 5 females; from the Kawkawlin River, Mich.,

_ August, 1895, 19 males, 17 females (J. B. Shearer); and from

Saginaw Bay, Mich., August, 1895, 5 females (J. B. resen §

Koenike (95 6: 206) records the taking of 3 specimens by J. B.

ee ee hie Deer Fincher Crock,” Canada.

He ites found in southern Russia, Sweden, Norway, Middle Europe,

152 ROBERT H. WOLCOTT

Note has been made of the fact that the length of legs, as given

above, does not agree with that given by Piersig for L. undulata.

Nor do the writer’s specimens agree in that regard with specimens

from Switzerland, received from Koenike. But after careful com-

parison there seems not to be sufficient reason to doubt their specific

identity. And the author prefers to err on the side of conservatism

in the matter of separating the American species from 5g allied

European forms.

4. Limnesia paucispina n. sp.

A species bearing a close resemblance to L. histrionica and L.

undulata and evidently allied to them, but distinguished at once by

the stouter palpi, with a very short papilla on the second segment,

by the scarcity of spines on palpi and legs, and the character of the

genital area.

The body of the single female specimen studied is broadly oval

and evenly rounded at both ends; as far as can be judged it was only

of moderate height. It is 0.87 mm. long by 0.70 mm. wide. The

surface is marked by fine lines. The usual glands are present and

for the most part they possess the very short, slender hairs found

generally among species of this genus, but the pair of dorsal glands

situated farthest posteriad have very long slender hairs, projecting

behind the body, and 0.11 mm. in length.

The eyes are very large and not only are the two of each side

close together, but those of opposite sides are separated by a nar-

rower interval than in the allied species, the anterior lenses being

only 0.18 mm. apart, while the lenses themselves are over one-fourth

as far across, being 48 4 in diameter. The antenniform bristles are

similar to those of the allied species but longer than in either,

measuring 33 #; they are 0.17 mm. apart.

The palpi (Pl. XIII, fig. 11) are over half the length of the body,

much wider than the first pair of legs, and stouter, especially the

two distal segments, than in the allied species. The proportional

length of segments is 6, 26, 20, 37, 11; which shows that the distal

segments are also relatively shorter. The total length of papilla

and spine on seg. 2 is a little over one-third the thickness of the

segment, but of this the spine, which is much longer than in the

other species, furnishes four-fifths, the papilla being extremely short.

On the inner side of seg. 2 are three small spines, and on the outer

NORTH AMERICAN SPECIES OF LIMNESIA 153

Bina ward the bese and-one at: the tip; seg. 3 has two

on the inner side and a longer and a shorter one on the outer. Seg.

_ 4 is thicker than in either of the other two species with which this

is compared, being one-fifth as thick as long and nearly one-half

as thick as seg. 2; the excavation toward the tip is shorter and

deeper. Seg. 5 is noticeably more blunt.

Maxillary shields and epimera bearing a close resemblance to

= those of L. histrionica. The sides of the first are straight, how-

___ ever, and the inner ends of epp. I behind it not so closely in apposition

gd 10) and a little broader. The medio-posterior mar-

__ gin of ep. IV is more strongly sinuate.

The legs are relatively long, rather slender, and bear relatively

_-yery few spines and hairs, which are themselves, however, very long.

At the tip of III 3 and also of III 4 is an extremely long, slender

hair, and on III 5 are six swimming-hairs. On IV 4 are three

-swimming-hairs, two at the middle of the segment and one at the

a "tip, while on IV 5 are three and one in the corresponding situations.

___ On the tips of IV 4 and IV 5 are also two very peculiar spines, flat,

a _ ‘Spatulate, and with the pectinations long and confined to the tip.

“The genital area (Pl. XIII, fig. 10) is quite different from L.

histrionica and resembles that of L. maculata to some extent. All

the acetabula are very large, but the anterior are the largest of all

and are elliptical in form, while the distance between the first and

second is equal to only half the diameter of the second. A line

connecting the posterior angles of epp. IV passes through the last

pair.

' mim.

Es ichd bavesdacecaercccustncesince sdgssnscepegenceseeve 0.87

M11. cll Gi eceits cod bbs cbs kaokeonc apgres sagrecsenesas 0.70

SIUEE Gs BU ee Ge tbh 0600s dude boc sue ten dee die cet cccsdcecssececcese 0.67

a WO bs S bce cedisesesl ids cdocseecbe tevececovedecstusccecece 083

Leg Ul... o8t

MEM oc c0ccncnccrcccsccenessccsecceseccncceecscereescascesseseene 1.06

Mire ccbbs baep ope Stscegbaden Chae tials 9c can ncanpeshesesse ost

NIUE cl ot bavcda deer eun cecedve teu dn ep aebe cous stneas 0.16

NE WIND BION. 0 ocd on do os ch edees Cocscddetcteveveusscvedcecese O13

____ Confused with other species when collected, no note of the color

ig available

Type retained in the author's collection.

154 ROBERT H. WOLCOTT

The single female specimen was taken in Powers’ Lakes, Grand

Rapids, Mich., August 9, 1895.

The name is in allusion to the scarcity of hairs and spines on the

appendages, which is quite noticeable in contrast to the two pre-

ceding species.

5. Limnesia puteorum Stoll (!)

Limnesia puteorum Stoll, 87; 14, 48, pl. VII, fig. 3.

Limnesia puteorum Stoll seems to be characterized by the nar-

rowness of the palpi, by the presence of a spine on palp. seg. 2 set

directly upon the flexor surface and not borne upon a papilla, and

by having a genital area similar to that of L. maculata. The species

here described possesses all these characters and while the writer

does not feel perfectly sure of the identification he prefers to con-

sider the two as the same until comparison of material from the

locality from which Stoll’s species was described shall prove the

identity or distinctness of the two.

The two female specimens to be described were received in a

dry condition, the vial in which they were sent having been broken

in transit, so it is only possible to make general statements in re-

gard to a certain details. The form seems to have been broadly

oval, the body about 1.3 mm. by 1.1 mm. in size, and the surface

marked by lines.

The eyes are small, and the two lenses on either side widely

separated, a space of 80 yz intervening between them; the anterior

lenses of the two sides are separated by a distance equal to 0.32 mm.,

while the posterior are a little farther apart. The antenniform

bristles are long, slender, and curved; they measure 80 g in length

and are 0.19 mm. apart.

The palpi (Pl. XIII, fig. 12) are about the width of the first pair

of legs, and bear a close resemblance to those of L. connata Koenike,

to which the species seems closest related, and also a certain sim-

ilarity to the preceding species. The spine on the flexor side of

seg. 2 is about 10 plong, is slightly bent, is directed forward,

tapers to a point, and about it the chitin of the integument is raised

up to form a socket, although there is present no papilla of the

character seen in the preceding forms. The spines are partly broken

but their arrangement seems to be similar to those shown in Piersig’s

figure of L. connata (97: Pl. XXIII, fig. 58d), except that there

NORTH AMERICAN SPECIES OF LIMNESIA 155

are about six on the inner side of seg. 2. The excavation at the

: tip of seg. 4 is shallow and the two hairs seem to be placed the one

midway between the other and the tip. Seg. 5 is short and relatively

thick at the base. The proportional length of segments is 5, 26,

AQ, 40, 10.

____ Maxillary shield rather narrow, sides rounded ; inner ends of epp.

___ I produced inward, nearly meeting behind it. Spaces between

‘epimera of only moderate width. Medio-posterior margins of epp.

Ss Poav widely divergent, and convex throughout their length. A line

ee ee

_ The legs are short and rather slender, well provided with spines,

of which few are pectinate. On III 5 appear to be from six to eight

Swimming-hairs, and on IV 4 and IV 5 about ten or eleven each,

of which one or two are at the tip. Leg III is slightly longer than

leg II, mostly due to the elongation of segs. 4 and 5.

The genital area (Pl. XIII, fig. 13) is very similar to that of L.

_ maculata, but is slightly narrower.

MEASUREMENTS Femace

mm.

Nace. ai le eel eau te wick aks bpgiad eae Make neeaein ee & 1.30

oe rts vas Ck adn on oh Coc au ap VHRUh bE ade o4e 86404 1.10

Ct cca. Stuns undone ionecedeadeoateerepavcedias dad 0.79

TEE. cE Ldtads dak nddshaghnaess adsareue 64ers sa odes wae 0.92

TI SUC ka W0Ue aide 605 dss 0 cdeWie dude sua uvdede bude dacesdanses 0.93

MLL albaiiecobns Us odedn s¥udue tae dctadnbdbe cvacéeense 1.23

ei as cca caniies og 6b dad enbaeens traces 6ue 0.24

MEE {7 Tole. be Cen oCb sh cbebastrecesipecscest codes O17

Nothing can be said of the color.

The two females under examination were received from Dr. Alf.

Dugés, and were collected at Guanajuato, Mexico. Stoll’s speci-

mens came from Guatemala.

This seems to be a very distinct species. The other forms lacking

a papilla on palp. seg. 2 are L. scutellata Koenike and L. lucifera

Koenike, both from Madagascar and both very different in very

many respects, and L. connata Koenike, found in various parts of

Europe, which it more closely resembles, but from which it differs

especially in the character of the genital area.

156 ROBERT H. WOLCOTT

6. Limnesia maculata (Miller)

Hydrachna maculata Miller, 1776; 191, no. 2289. 1781; 81, pl.

XI, fig. 3.

Limnesia venustula Koch, 35, pt. 6, fig. 10.

Limnesia rutilata Koch, 35; pt. 6, fig. 11.

Limnesia phoenicea Koch, 35; pt. 6, fig. 12.

Limnesia attalica Koch, 35; pt. 6, fig. 15.

Limnesia cyanipes Koch, 35; pt. 6, fig. 19.

Limnesia vitellina Koch, 35; pt. 6, fig. 20.

Limnesia modesta Koch, 35; pt. 6, fig. 21.

Limnesia affinis Koch, 35; pt. 7, fig. 7.

Limnesia magna Kramer, 75; 312, pl. IX, figs. 21 a, 21 b.

Limnesia maculata can be at once distinguished by the smallness

of its palpi and the abundance of long hairs and spines on the legs,

including swimming-hairs, beside minor details of structure.

This is one of the largest of our species, specimens being nu-

merous the lengths of which range from 1.6 mm. to 1.8 mm. and one

under observation being 2.14 mm. long and 1.67 mm. in width.

The body is oval, moderately high, quite evenly arched, and evenly

rounded at both ends.

The integument is marked by fine lines. The eyes are small and

very close together; in a specimen about 1.65 mm. long the diam-

eter of the anterior lens is 55 # and the distance separating those

of the opposite sides about 0.4 mm. The antenniform bristles are,

in the same specimen, 0.35 mm. apart, are short, being only about

32 /# long, and are stout, flattened, and pectinate.

The palpi (Pl. XIII, fig. 15) are very small, being not only

very short but also hardly as wide as the first pair of legs. On

seg. 2 the flexor surface in its distal half is projected to form a

broad-based papilla equal in height to one-third the thickness of

the segment and into the end of this is inserted, and directed ventrad

and caudad, a short, blunt, fusiform spine. On the outer side of

this segment are two long spines, on the inner four or five which

are pectinate; while on seg. 3 are three spines on the outer side and

two on the inner. From rather a narrow proximal end, seg. 4

gradually increases in thickness to just before the middle, where

is its widest point; while the distal excavation begins at about the

middle, extending to the tip. In this excavation are several hairs

NORTH AMERICAN SPECIES OF LIMNESIA 157

springiig from minute papillae while on the dorsal margin and on

ie the two sides of the segment are several more very minute hairs.

Just before the terminal claws on seg. 5, dorsally and ventrally, are

two hairs. The proportional lengths of the segments are 5, 28,

17, 40, 10.

The maxillary shield is small, not over half the length of ep. I,

are long, moderately heavy and very abundantly sup-

plied with long hairs and spines. They increase in length from

first but III is only slightly longer than II. The number

of swimming-hairs is not uniform but they are much more nu-

merous than in any other species examined. On III 4 and IV 4 are

from eight to ten or even twelve of these, and on IIIs and IV 5

ming hairs. Few spines are pectinate.

The genital area of the female (PI. XIII, fig. 14) is pyriform,

and with the sides rather strongly excavated. The acetabula are

large, the posterior circular and the first two slightly elliptical, and

between the first two is a space equal to the diameter of one of them

or a trifle less. In the case of the male, the two anterior acetabula

are markedly elliptical and the distance between them is only about

half their lesser diameter.

MEASUREMENTS Mate Fewace

mm. min.

MME: hed das an pse¥erecseedieenesabonees 1.05 1.49

MU, 55d ined cede sseed 6s eh dbetaduntice bites t 083 1,22

Til ths kde chgebinnh cesinth enwebas anise dekeetdbennt 0.93 1.03

cn canbe sndshadkanpeanadenpassdenhenssatedabe 1.35 1.46

EEN ds 55 gus vn onaehi anaes banker d4orease cet te de 1.38 1.52

aN DEL waksleedocbhsacedese hes acadecaenasgetioens 1.78 1.92

Daadeebacdc cnacceenednacyheesevnséoosseeseseane 0.48 0.52

EE MUNN QUE: vce cccke dds ccobetcicesscccosdacs 0.24 0.30

ST CORMAN GEOR. cccccncseosscnsce cvccrccoeuseuns 0.27 0.26

158 ROBERT H. WOLCOTT

Specimens from Lake St. Clair were, according to field notes,

“dull-greenish with very narrow lines of light and six vermilion

patches; eyes red and black; legs blue.” Others were “yellowish

with blackish patches; eyes purplish-brown; appendages greenish-

blue.” Still others from Charlevoix “pale yellowish-brown, marked

with olive-brown and red; few white lines; appendages bright blue;

eyes black.” The red patches referred to were uniform in location

and were placed as follows: One anteriorly and one posteriorly in

the dorsal median line, the former one-third the way from the an-

terior margin, the latter near the posterior margin; two others, one

on either side opposite the anterior dorsal; two more on either side

even with the posterior dorsal.

Of L. maculata specimens are at hand from the following localities :

Lake Chautauqua, N. Y., August, 1897, one male (R. H. Johnson) ;

Lake St. Clair, Mich., summer of 1893, 40'¢', 5 29; Reed’s Lake,

Grand Rapids, Mich., July 23, 1898, one female; Pine Lake,

Charlevoix, Mich., July 24, 1894, one female; Les Chenaux Island,

northern Lake Huron, August, 1895 (J. B. Shearer). It thus

seems to be rather widely distributed, though not common.

It is one of the best-known European forms and Piersig records

it from Finland, Russia, Sweden, Germany, Bohemia, Austria, Italy,

Switzerland, France, and England.

Ill. TABLE FOR DETERMINATION OF SPECIES

The following table will serve for the determination of the de-

scribed North American forms, the species described by Stoll as

L. longipalpis being not placed.

1. A prominent peg-like spine on the flexor surface of palp. seg. 2....... |

No such eplne pemeetltsica cc c's «s0cacackicane shoes sheen L. laeta Stoll

2. Body covered with a chitinous meshwork...............- L. cornuta n. sp.

Body soft and marked by fine limes. .....ccccsccccoccssscscccescansesane 3

3. Spine on flexor surface of palp. seg. 2 borne on a papilla. . erreer |

Spine on flexor surface of palp. seg. 2 borne directly on the ‘orie

L. puteorum Stoll ( Z »

4. The papilla slender and chimney like. ............60ceccccceseccccveeees

The papilla an outswelling of the whole distal half of the flexor aiead

Of the segment... ci icscceccocede ch0cos beeeinss eb en eeeneenn Een vs

5. The papilla very short and spine relatively long........ te en n. sp.

The papilla very long and spine relatively short. . . 6

6. The two anterior acetabula of the genital area seperated. rip a ‘egete tes

NORTH AMERICAN SPECIES OF LIMNESIA 159

.. ERs diner of either... . .L. histrionica (Herm.)

“Fike same space in the female equal to from ouc and a half to two times

the diameter of the acetabula; in the male this space is less, but still

_ greater than in the preceding species. .... ..L. undulata (Mill)

BI cots vu: 2 cams Saitecsn Ga tase ch saotaas tod ers

ee sestbsc cama --..-L. maculata ( Mill.)

Spine long, of nearly uniform calibre, and directed directly ventrad,

es L, Koenikei Piersig

BIBLIOGRAPHY

Heemawn, J. F.

04. Mémoire aptérologique. Strasbourg, 1804.

£. wiss. Zool, XXXV, pt. 4, 1881, 613-628.

956. Nordamerikanische Hydrachniden. Abh. des naturwiss. Ver. zu

a Bremen, XIII, 1895, 167-226, Pls. I-III. Also separate.

75. Beitrige zur Naturgeschichte der Hydrachniden. Arch. f. Natur-

; gesch., XLI, 1875, 263-332.

Kaenvowsxy, M. E.

5. [Les Acariens d’eau douce (Hydrachnides) de la Russie meridionale}.

(Russian) [Arb. Naturf. Ges. Charkow]. XVIII, 1885, 209-358, 2 pls.

Lesext, H.

79. Matériaux pour servir 4 l'étude de la faune profonde du lac Léman,

par Dr. F. A. Forel. VI Série. Hydrachnides du Léman. Bull. Soc.

Vaud. Sc. Natur., XVI, 1879, 327-377, 2 pls.

Méuizz, O. F.

1776. Zoologiae Danicae prodromus, etc. Hafniac, 1776. (274 pp.)

1781. Hydrachnae, quas in aquis Daniae palustribus, etc. Lipsiae, 1781.

(88 pp., 11 pls.)

Neuman, C. J.

- 70. + Vestergéthlands Hydrachnider. Ofvers. af Kongl. Vet.-Akad. Férh.,

1870, no. 2, 105~110.

Bo. Om Sveriges Hydrachnider. Kongl. Svenska Vet.-Akad. Hndigr.,

XVIL Separate, 1880. (123 pp. 14 pls.)

160 ROBERT H. WOLCOTT

Prersic, Ricu.

97. Deutschlands Hydrachniden. Bibl. Zool., XXII a .

1900. (601 pp., 51 pls.)

Prersic, Ricnw. [ann Loumann, H.].

1901. Hydrachnidae [und Halacaridae]. Das Tierreich, XIII. Berlin,

June, 1901. (354 pp., 87 figs.) (Hydrachnidae by Piersig.) 3 |

Soar, C. D. ;

97. British Hydrachnidae. Part VII. Limnesia. Int. Jour. ulerhe aoe

Nat. Sci., 3d ser., VIL, 23-26, Pl. III, figs. 1-9. (A series of articles

ran from Vol. V, 1895, to Vol. VII, 1897.)

Stott, Orro.

87. Hydrachnidae. Godman and Salvin’s Biologia Centrali-Americana,

Zool., part LIX, 1887, 9-15, 46-48, Pls. VII-XI. :

Tuor, Sic.

99. Tredie Bidrag til Kundskaben om Norges Hydrachnider. Archiv. f.

Math. og Naturv., XXL, no. 5. (64 pp., Pls. VII-XVIL)

; NORTH AMERICAN SPECIES OF LIMNESIA 161

EXPLANATION OF PLATES

made from slides and with the camera, unless otherwise

Plate XI

Fics. 1-5. L. cornuta

“Rosco bites of male from Grad Rap Mich X 18s.

e Fic. & L. undulata

_ Genital area of female; 175.

Plate XIII

Fie. 9. ——.

oa Fics. 10, 11. L. pawcispina

rs tice of tes X130. From

s. Inner side of palpus of female; X18s.

Fics. 12, 13. L. puteorum (1)

Inner side of palpus of female; 130.

Genital area of female; X 18s.

Fics. 14, 15. L. maculata

Epimeral field and genital area of female; X60.

Inner side of palpus of female; X 110,

NECROLOGY

CHARLES MARVIN VORCE

or CLevetann, Onto

a2 hares Marvin Vorce was born in Pulaski, N. Y., November

‘He ‘possessed a naturally delicate, thoughtful, studious in

ent and exceptional literary taste and ability, all of which were

cre by exercise and study as long as he lived. To him edu-

cation was an instinct, a mode of living, a necessary condition of

ace, rather than a task to be performed under durance for a

limited time and then dropped with a feeling of relief.

His course of life was interrupted by the breaking out of the

_ Civil War, when he, at the age of eighteen years, devoted his life

_ to the country’s service from the call for three months’ volunteers

_ to the close of the conflict. His vigor was somewhat impaired by

‘the hardships of war—including an attack of typhoid fever.

_ On January 27, 1868, he married Miss Evalyn C. Marshall, of

- Oregon, Illinois. He is survived by his widow and two sons aged

| 31 and 33 years.

_ As a man, his was a character of the strictest integrity and the

__ highest honor. He was modest to a fault, making claim to only

_ moderate merit and so fearful of seeming to seck notoriety that he

would only accept it when forced upon him; which often prevented

¥ eames int by his most intimate friends. But

his friendship was limited only by his opportunities. His hospi-

tality was free and cordial, evidently one of his chief pleasures;

and in return he keenly appreciated every act of kindness, however

small. He was one of those rare and priceless friends, quiet, stead-

_ fast, generous, helpful, but never exacting, who, however much they

__ may have been appreciated and rewarded, always leave their friends

_ with a strong wish that they could have had opportunity to show

_ more appreciation and to contribute more to their happiness before

it was forever too late.

164 CHARLES MARVIN VORCE

His education seemed to lean instinctively in the direction of

physics and to means and methods of precision, which, in connection

with his exceptional literary ability, may well have determined the

choice of his profession and of his scientific specialty.

As an attorney he drifted in the direction of mechanics, chemistry,

etc., and finally became a very prominent “patent lawyer.”

He had distinctly scientific tastes, and was early fascinated with

the rapid growth and vast possibilities of microscopy, which he

almost unconsciously adopted as his second specialty, to give char-

acter and interest to his hours of leisure and periods of rest. His

great versatility enabled him at first to gain a considerable familiarity

with microscopy as a whole, and to take a wholesome interest in the

labors of those who were cultivating its various branches. Such

a character was most timely during that formative stage when micros-

copy was growing from an elegant and admirable recreation and a

single specialty in science and art, into the large group of almost

boundless specialties that it is now. But as the field outgrew even

the superficial vision of any one person, he fixed his attention mainly

upon portions of two divisions of the subject.

His work in biology was largely concerned with some of the lower

forms, and especially in the direction of pond life, as it was then

called. His study and writings, including the two studious and

elaborately illustrated papers on the forms observed in the water

of Lake Erie, in 1881-2, were pioneer work in the present revival

of such studies under the name of limnology, a subject which has

since then become the most prominent and important feature, not to

say the specialty, of this Society; and it is reasonably hoped that the

society may in the near future be fully recognized as the organ of

the workers in this new and very important specialty, to the mutual

advantage of both parties.

In economic microscopy, on the other hand, he did much of ad-

vanced work, mostly in the direction of jurisprudence, where it

harmonized to advantage with his regular profession. He applied

the microscope to good purpose in the detection of adulterations in

food and medicines, of falsification in hand-writing, and in the de-

tection and discrimination of blood stains. He participated in many

of the important murder trials that were held in his county during

the last quarter-century, and furnished much of the technical testi-

mony that could be obtained only by expert microsopical investiga-

a ”.s

CHARLES MARVIN VORCE 165

ET ht Bt wae, 20 eveds-conaled, thorough, precise, and

sctly candid. He was most skilled in recognizing the facts that

r x brought within sight by the microscope, and appreciating them

ie aee value, and applying them accordingly ; but he was con-

. nae and just, and incapable of making exaggerated claims or

just inferences, or of expressing reckless or unwarranted opinions.

is position as an expert was inflexibly judicial, and therefore one

i Te rend be greatly Sager Sy Seloeing: His

pc paper on “ Fees of Experts,” in 1890, takes a stand in

se Micrometry, which was often a prominent and

ymetimes the principal feature in these studies, was one of his

vorite departments, in which he greatly excelled. In connection

' he studies of handwriting he contrived a special and useful

icro. ¢ stand for that purpose, which was published in 1891,

which he used for his own work.

lany of his papers on these and similar subjects were introduced

ee te tenner eeited ie ies Pemeeeer

in other S oetages

Every trait in Mr. Vorce’s character led him irresistibly to join

Seeeeende and d ascites in ther various society enterprises, and

i him for the highest usefulness therein. He was one of

ne founders of the Cleveland Microscopical Society, of which he

secretary and afterwards president. He was also a Fellow

Is Royal Microscopical Society of London, from 1881.

i eo most important participation was naturally in our own

tional body, the American Society of Microscopists, now Ameri-

_ an Microscopical Society, as the older members will remember with

_ pleasure and gratitude.

He was a member of the National Microscopical Congress held

Indianapolis in August, 1878, where he was at once recognized

; one of the leading spirits and one of the safest advisers. He was

_ chairman of the nominating committee for permanent officers of

¢ convention, and a prominent member of the committee on a

smanent national organization; these being positions of greatest

and responsibility in giving origin and character to the

merican Society of Microscopists. He was Second Vice-President

the first meeting of the fully organized society at Buffalo in 1879,

and First Vice-President at the Pittsburg meeting in 1887, and the

New York meeting in 1900. It might truly be added that only his

166 CHARLES MARVIN VORCE

excessive modesty stood between himself and the Presidency; for

he was often urged to accept the position, but as he happened to be

a member of the nominating committee at the time no reasons or

pressure could induce him to allow his name to be mentioned. Gen-

erally, however, he was barred from that office by the unwritten

law, which was early adopted, that the President for the next meet-

ing should always be chosen from among those present at the time

of election, and the fact that his business engagements were so

exacting that he could seldom be certain of attending two meetings

in succession.

He labored strenuously, from first to last, to assist in building up

and holding up the society. He was always a welcome associate,

and often a chosen leader in any kind of committee work, where

his quiet and unpretentious manners, thoughtful habits, scholarly

attainments, and great organizing ability made him both congenial

and efficient. Equally faithful was he in all the minor opportunities

of membership. He was an early subscriber to the Spencer-Tolles

fund for encouraging microscopical research, was as constant an

attendant upon the meetings as the emergencies of business would

allow, and often at a large sacrifice of profitable engagements. He

presented numerous papers of every grade from little notes on

useful details in technic to elaborate studies in natural history or

economic microscopy in which he was a recognized expert. At the

meetings he joined in discussions and his remarks were always

practical, suggestive, and helpful. Among the special activities of

the society, by which during its early years its members were inter-

ested and assisted, were the so-called “working sessions.” These

will be remembered by the older members as informal afternoon

conferences, held during the “eighties” for demonstrations in tech-

nic. Mr. Vorce was always ready to contribute a share from

his rich experience, presenting such important specialties as mi-

crometry, photomicrography, detection of adulterations, etc. In

planning for the Cleveland meeting in 1885, the executive com-

mittee requested him to take charge of that department. He ac-

cepted the very onerous duty and executed it with his usual thor-

oughness and good judgment. He prepared in advance a carefully

considered scheme to make the best use of the available resources

and engaged the participation of members able to contribute from

their own specialties. Notwithstanding the inevitable disappoint-

CHARLES MARVIN VORCE 167

Ry cox gros cr augur tien estat san

t occupied with his own instructive illustrations in practical

rometry; and it is no injustice to other sessions, several of

which were excellent, to call this the most complete and successful

the series. De ee

Fesolt was enthusiastically offered, though evidently imprac

that all the afternoons of the meetings be reserved for such

for competition. waved ie wads ae

. E. H. Griffith for the best mounts showing the ap-

microscope to the detection of adulterations in food.

t i in 1880 it was awarded to an anonymous

es > Proved Oo te Vorce, he having offered some

tis that field, merely to assist in the enterprise

his friends induce him to accept the first as a compliment to

____ At the Cleveland meeting in 1885 came the opportunity to enter-

_ tain the Society in his own town, and he devoted himself to the work

_ with a love and an aptness that was boundless. From the official

st tireless worker among the local entertainers. During more

eM years his increasing business as a “patent lawyer” required

_ Tong absences from home, or devotion to work in absorbing cases,

168 CHARLES MARVIN VORCE

in a manner that interfered with his scientific work, and especially

with attendance at the summer meetings. He however retained his

interest throughout. It is noticeable that his last paper was an ex-

cellent obituary of his distinguished friend, and ours, the late Hon.

J. D. Cox, for the 1900 meeting at New York.

Intimately connected with the American Microscopical Society,

though independent in its inception, the National Committee on

Micrometry was formed, on the initiative of the Troy Scientific

Association. President F. A. P. Barnard of Columbia College, per-

haps the leading theoretical metrologist of the world at that time,

was chairman; and each of the societies connected with the Micro-

scopical Congress was represented by a member on the committee.

Mr. Vorce ably represented the Cleveland Microscopical Society.

In this work he was in his native element. Everything that he could

do was evidently a labor of love and a personal delight. During the

period of the committee’s activity his constant and untiring partici-

pation was a model of thoughtful, discreet, generous, and altogether

successful committee work.

At the next meeting of the American Microscopical Society the

committee was recognized by that body and authorized to continue

as its representative. It was easy to decide on the metric system

and the 0.001 mm. unit; but it required the work of years to be

able to apply that unit, or any other one, to micrometry with any

known degree of precision. The commercial micrometers in uni-

versal use were of as much authority as the carpenter’s pocket rule,

with no means of knowing which was the farthest wrong, or how

much wrong was the nearest right.

Finally, with the cordial coéperation of Professor J. E. Hilgard,

of the U. S. Bureau of Weights and Measures, an exquisitely ruled

centimeter on a platino-iridium bar was obtained; and its actual

relations to the standard meter of the U. S. Coast Survey and to

several other meters of known value, and through them to the

“ Metre of the Archives” which had been adopted in 1870 by thirteen

governments as the international standard, was obtained. Its sub-

divisions were studied at great length by Professor Wm. A. Rogers,

then easily first in experience, skill, and success in such work, and

by others of known aptness and experience, including Mr. Vorce.

The precise relations of the various spaces to each other and to the

standard meter were determined, so far as the microscope was able __

to reveal them. Probably no centimeter of metal or of anything else

_ has ever received as much, or a small fraction of as much, of high-

_ class work as this. The plate was adopted as a national standard

by the A. M. S. and so-called copies (having known degrees of

_ correspondence with the standard) were prepared for use in testing

_ and correcting the micrometers employed in actual work. As a

_ result it is now possible to know the value of a working micrometer,

with a definiteness and certainty unattempted before.

__ Mr. Vorce was also one of the organizers of the American Postal

Microscopical Club. His altrustic spirit responded instantly and

_ cordially to the idea of a correspondence society, not selfishly limited

_ to a few experts or professionals who least of all needed encour-

agement or assistance, but open to all really qualified to participate

profitably, where all could take an interest in the work of others

along lines different from their own, and where those able to lead

_____ amd teach could see exactly where their friendly words and helpful

_ hints would be most useful. He was a manager for twenty years,

_____ from the foundation of the Club in 1875 to 1895, and Vice-President

since that time. He soon organized a local circuit in his own town,

____ and by his personal care made it for many years one of the strongest

amd best branches of the enterprise. There was nothing narrow-

___ minded, selfish, or provincial in his principles, his interests, or his acts.

___ A thorough cosmopolitan and a microscopist of the old school, like

__ Quekett, and Beale, and Carpenter, and many others that might be

___ mentioned, he cultivated and cherished microscopy in its broadest

_ ‘sense, both as a science and as an art. He was always ready to

contribute facts or ideas from his own special lines to those working

~ _ im other fields, and to take an appreciative interest in their own

special undertakings ; but he was pleased most of all to give friendly

hints, needed information, and suggestive criticism to amateurs or

beginners who were trying to enlarge their sphere of vision. In

contributing to the circulating boxes, he always made a serious

business of furnishing something having definite purpose connected

with it, and in writing something worth reading about it. His

circulating notes were models of general excellence and fitness for

| the purpose; being thoroughly accurate and scientific, but in con-

yersational and readable style, free from needless technicalities of

__ expression or ostentation of any kind, carefully, neatly, and closely

written with fine pointed pen and suitable ink, giving a great deal

ee ee

eS ee ee ‘

17° CHARLES MARVIN VORCE

on a page but extremely legible and without appearance of crowding,

and often accompanied with neat and illuminating pen drawings.

He often added voluntarily to inadequately described slides from

other contributors, not only casual remarks of importance but

elaborate and carefully studied notes when required to make them

useful. The Secretary knew him as one who, even in his busiest

years, could be depended upon to write, on request, scholarly and

instructive notes for difficult slides within his range of study. He

will be greatly missed by his friends in the Club, and scarcely less

by those members who knew him only by name as a very helpful

educator. It is a singular coincidence that Mr. Vorce died almost

at the same time as his neighbor and intimate friend, and long-time

associate in microscopy and in the Club, Mr. L. A. Willson. Hear-

ing of Mr. Vorce’s death, the Secretary wrote to Mr. Willson

asking for some information and assistance, only to receive from

strange hands information that Mr. Willson had died three days

before his friend.

Besides the records of his society work which found their way

into the microscopical journals he was a frequent contributor of

anything likely to be of use from the simplest hints in the technic

of obtaining, examining, and mounting objects, to formal and thor-

oughly prepared papers along the lines which most attracted his

attention. Not only were his contributions always more than wel-

come in all the American journals, but they were also appreciated

abroad. They were often represented by reprints, extracts, abstracts,

or references in the Journal of the Royal Microscopical Society, the

unquestioned standard in microscopy, at least of the English-speak-

ing world, in every volume of which, during the years of his greatest

activity, they found place, often to the extent of several times a year.

Mr. Vorce’s death was as remarkable as his life. On the morning

of December 18, 1901, he started, well and happy, for his office, but

telephoned that he would stop on the way to do some shopping. He

entered one of the great department stores, made his way slowly

through the holiday throng that crowded the aisles, and was quietly

selecting Christmas gifts for his friends, when, without warning,

he fell in a faint to the floor. But the rest that came so suddenly

was eternal. His long overtaxed system had reached its limit. The

gentle, courteous associate, the considerate and beloved friend, the

eminently useful, modestly great man had finished his work.

R. H. Warp.

PROCEEDINGS

. American Microscopical Society

MINUTES OF THE ANNUAL MEETING

a HELD IN

_ PITTSBURG, PENNSYLVANIA, JUNE 27 AND 28, 1902

_ The twenty-fifth annual meeting of the Society was called to order

by President Charles E. Bessey in the Phipps Botanical Laboratory,

irg, Pa., at 3:00 p.m., Friday, June 27, 1902. Mr. Magnus

jum, Custodian of the Society, and chairman of the local com-

Bc cceentiiode Ganed ie aednccen cee:

‘Mr. Presiwent ano MeMpers of THE AMERICAN MICROSCOPICAL

tety : This is the third time this city has been honored with your

visit and the first time that the united body of scientists assembles

our midst. Not more than about ten years ago Pittsburg was

wn merely as a city of smoke, coal, and iron, as one of the many

ny manufacturing places of America. To-day it is the proud

-mant center of the world, known wherever civilization rears

$ torch. But this city is not content with achievements merely

“material, but in the field of art, science, and education it longs also

) be supreme. With gathered wealth its citizens have ceased con-

fining themselves merely to accumulation, the period of generous

disbursement has commenced, and with the example set by our Car-

Negie, Pittsburg indulges in the justifiable hope to lead at an early

day with the largest and most complete public library system, and to

have educational facilities, practical and theoretical, in all branches,

_ Second to none. We also have a working museum, yet an infant,

but with such energy and activity promising soon to be a giant and

¢ equal of any of the oldest institutions; and our efforts in music

and fine arts are known in all art centers, a surprise to strangers and

pride to our people. On behalf of such city and its inhabitants,

172 AMERICAN MICROSCOPICAL SOCIETY

in the name of the numerous committees of arrangement, and for the

local members of this society I have the honor to bid you a hearty

and sincere welcome.

When you visited us before you were the only guest; now you

come in compahy with others. Then you received our whole atten-

tion ; now it is divided, but not the less cordial, nor because entitled

to diminished esteem. Your meeting before the main scientific

body and leading, in point of time, in the great feast of knowledge

and reason, is truly emblematical of the relation of microscopy to

science at large. What matters it whether those critically enclined

are right or wrong in denying to microscopy the rank of a science?

Suppose the microscope has become merely a valued tool used and

needed in every branch of practical and scientific investigation? Is

not this wonderful tube and familiarity with its best use the door to

the hall of knowledge, the sun to lighten dark and hidden places;

in short, is it not the very eye of science? If this instrument has

become domesticated in the different arts and branches of science,

is not the credit for this domestication largely due to the stimulus

given by this society to the use, methods of application, and im-

provements of the instrument? Whether this society has a function

or fills a place is a question which can be answered from the shelves

of almost every known scientific library.

And if microscopy be no science, what of microscopists? If

painstaking, patient, unselfish, and unremitting labor, the last in

every sense and meaning of the word, is not scientific effort, then

there is no science.

Hence you may be assured that you and your work are duly ap-

preciated. In the hope that your gathering here will be as pleasant

and profitable to you as your visit is deemed an honor by this city,

I again welcome you, each and all, with my whole heart.

The address of welcome was responded to in a felicitous manner

by the President after which the usual order of business was taken

up. The report of the Custodian was submitted and referred to a

committee consisting of Messrs. Elliott and Ives for auditing. In

the discussion of the report several members referred in strong terms

to the valuable services rendered the Society on the part of the

Custodian. It was on motion decided that the fiscal year should

close October 1, and that the books of the Treasurer should then be

forwarded to the auditing committee for examination, the result of

EE — ————— — a

PROCEEDINGS OF THE 173

made. ope ghed serpent Roscoe Pound and Dr. F. E.

Bi gereny:s Sor doce

ie j Es tae sceaks of catadtanienion Le: which were

t printed elsewhere. Some suggestions were made regarding the

jcrease in the membership and in the list of subscribers and with

s end in view there was recommended the appointment of an

\‘ Secretary. It was further reported that copies of the

circular outlining the subscriptions to and disposal of the Spencer-

_ Tolles Fund had been sent to each subscriber to that fund. It was

further recommended that the fees of life memberships be placed

at interest under the charge of the Custodian, and that the principal

be held perpetually intact to constitute part of the invested funds

of the society, that the Custodian should transmit to the Treasurer

ne ree can

interest earned by this fund, and that any balance of the income

during the lifetime of the member, together with the entire income

_ thereafter, should be included in the income of the research fund

of the Society. On motion the recommendations of the Secretary

‘were referred to the Executive Committee for final action. The

amendments to the constitution proposed last year and printed on

‘page 276 of the Transactions, Volume 23, were read and adopted in

f aecordance with the recommendation of the Executive Committee.

‘The nominating committee consisting of Messrs. Krauss, Elrod,

| on Rearmompee and Ward was elected.

The following papers were read:

a On the comparative histology of animals: H. B. Ward, Lincoln,

Nebr. ; discussed by Messrs. Krauss, Pflaum, Schoney, and Elrod.

3 On the development of the liver in the pig: D. C. Hilton, Chicago,

. TL; discussed by Dr. Krauss.

On two growths of Chlamydomonas in Connecticut : F. S. Hollis,

_ New Haven, Conn.; discussed by Messrs. Bessey and Ward.

G —

SECOND SESSION

; ~ At 8:00 p.m. the Society convened in the lecture hall at the Car-

es Institute and a large audience of members and guests listened

174 PROCEEDINGS OF THE

to the annual address of the President, Dr. Charles E. Bessey. After

an appropriate vote of thanks for the admirable address the Society

adjourned until the following morning.

THIRD SESSION

The Society met at 10 a.m., Saturday, June 28, in the lecture hall

of the Carnegie Institute and listened to the reading of papers in

connection with lantern demonstrations. The following papers were

presented and discussed :

A new form of combined lantern and microscope for projection

purposes: Mr. L. B. Elliott, Rochester, N. Y.

Stereoscopic photomicrography with high powers: Mr. F. E. Ives,

Philadelphia, Pa., with demonstrations of the apparatus and the

photographs.

Principles of microtome construction with illustrations of new

forms of the instrument: Mr. L. B. Elliott, Rochester, N. Y.

The Society then adjourned.

FOURTH SESSION

At 2:00 p.m. the Society convened in the Phipps Botanical Labora-

tory and the following papers were read and discussed :

A method of staining glandular tissue: Professor M. J. Elrod,

Missoula, Mont.

A rearrangement of the genera and species of the Phycomycetes:

Dr. Charles E. Bessey, Lincoln, Nebr.

Data for the determination of human entozoa: Dr. Henry B.

Ward, Lincoln, Nebr.

A method of concentrating plankton without net or filter: Pro-

fessor B. L. Seawell, Warrensburg, Mo.

Prevention of the pedetic or Brownian movement in milk or other

liquids with minute objects in suspension: Professor S. H. Gage of

Ithaca, N. Y.

The following papers were then read by title and referred to the

Executive Committee to print if found suitable:

Cultural studies of a nematode associated with plant decay: Pro-

fessor Haven Metcalf, Clemson College, S. C.

Review of American species of Limnesia: Dr. Robert H. Wolcott,

Lincoln, Nebr.

AMERICAN MICROSCOPICAL SOCIETY 175

ah: & Réetont: wastes’ e-aeekee, wae thea read: nd

printed as a slight token of the appreciation felt by the

ty for the faithful service of one who had been so unceasing

_ The following amendments to the Constitution of the Society were

offered for consideration, referred to the Executive Committee for

alte in phraseology if necessary, ordered printed as approved

by that committee, and in accordance with the rule laid on the table

(To. amend art. III by striking out all after the word “office” and

Substituting as follows: together with a Secretary, a Treasurer, and

‘a Custodian, who shall each be elected for three years, be eligible

for reelection and whose terms of office shall not be coterminous.

To amend art. IV by striking out after the word “presides” the

__ words “of the Treasurer to act as custodian of the property of the

Society” and substituting therefor: of the Custodian to receive and

__ manage the property and permanent funds of the Society under the

_ direction of the Executive Committee and in conjunction with a

permanent committee to be called the Spencer-Tolles Fund Com-

___ mittee, and to make a full and specific annual report of the condition

of all the property funds and effects in his charge.

To amend art. VII by adding thereto: But any person duly elected

___ may upon payment of $50 at one time, or in instalments within the

game year, become a life member entitled to all the privileges of

membership, but exempt from further dues and fees. All life mem-

_ bership fees shall become part of the Spencer-Tolles Fund, but

_ during the life of such member his dues shall be paid out of the

_ income of said fund. A list of all life-members and of all persons

of bodies who have made donations to the Spencer-Tolles Fund in

es to over, shall be printed in every issue of the Transac-

tions. The income of said fund shall be used exclusively for the

2 _ encouragement and support of original investigations within the

176 PROCEEDINGS OF THE.

scope and purpose of this Society. The principal of the fund shall

be kept inviolate.

A telegram was read from the Business Men’s League of St.

Louis, Mo., inviting the Society to hold its 1904 meeting in that

city. The invitation was referred to the Executive Committee

with power to fix the location of the meeting and to determine fur-

ther whether the Society should join in the movement to hold

mid-winter meetings in Convocation Week.

The nominating committee reported, recommending the follow-

ing list of officers who were on ballot unanimously elected to serve

for one year:

President, Dr. E. A. Birge, University of Wisconsin, Madison, Wis.

First Vice-President, Dr. Wm. H. Seaman, Washington, D. C.

Second Vice-President, Dr. A. M. Holmes, Denver, Colo.

Assistant Secretary, Dr. R. H. Wolcott, University of Nebraska,

Lincoln, Nebr.

Elective members of Executive Committee: Mr. L. B. Elliott,

Rochester, N. Y.; Professor M. T. Elrod, Missoula, Mont.;

Dr. F. S. Hollis, Yale Medical School, New Haven, Conn.

A hearty vote of thanks was given the retiring President for his

able administration, to Dr. W. G. Holland, Director of the Carnegie

Institute, to the Local Committee, to the Director of the Phipps

Botanical Laboratory for numerous courtesies, and to Mr. Magnus

Pflaum for his work as head of the special local committee and for

providing the handsome souvenir silver badges. Thereupon the

Society adjourned subject to the call of the Executive Committee.

That evening the Society was entertained at a Summer Garden

Opera party by the special local committee under the leadership of

Mr. Pflaum. Those present enjoyed a delightful evening and were

warm in expressions of appreciation for the hospitality extended

to the Society.

Henry B. Warp,

Secretary.

MID-WINTER MEETING, WASHINGTON, D. C., JANUARY 1, 1903

Pursuant to a decision of the Executive Committee the mid-winter

meeting of the Society was called to order by President E. A. Birge

in the lecture room of Columbian University Law School, Wash-

ington, D. C., at 4:00 P.M., January I, 1903.

AMERICAN MICROSCOPICAL SOCIETY 177

_ The Executive Committee recommended that a sum not to ex-

ceed $50 be appropriated from the income of the Spencer-Tolles

Fund, to assist in the publication of a paper by Mr. D. C. Hilton,

on the development of the liver in the pig, which on account of the

illustrations necessary could not be published otherwise. After

an extended discussion as to the policy to be adopted by the Society

in the use of the income of this Fund “for the encouragement of

research” as specifically required by the terms of the Fund, it was

voted that the publication of results which would otherwise remain

unknown or imperfectly presented was clearly for the encourage-

__ ment of research, and the recommendation of the Executive Com-

_ mittee was unanimously approved and adopted under the stipulation

that the paper be designated beneath the title “ Published under a

Se te Spencer-Tolles Fund.”

_ The matter of mid-winter meeting was taken up and discussed

b in extenso. The action of the Executive Committee in calling such

-, a meeting this year was approved and it was voted that for the

__ present the Society continue to hold a general meeting in connec-

tion with the other organizations meeting in Convocation Week,

but that in view of the large number of scientific programs already

announced and of the financial inability of the Society to print more

iP: - Papers than it now does, it is unwise to have an extended scientific

| Pfogram prepared for the mid-winter meeting; if, however, the

Executive Committee should deem it wise to change this plan at

any time, such change should be approved.

It was then ordered further that the Executive Committee be in-

structed to provide for a summer meeting at some suitable point

_ which would allow of demonstrations and field work with the view

of determining the desire of members to take part in such meeting.

The matter of an official monthly organ having been brought

before the Society by a communication regarding such a journal, it

___Was voted to refer the matter for investigation of details to a com-

mittee consisting of Messrs. Ward, Eigenmann, and Pflaum. The

_ committee was ordered to report at the summer meeting.

The Society then adjourned to inspect a demonstration of pro-

| jection apparatus by Mr. L. B. Elliot.

a Henry B. Warp,

Secretary.

178 AMERICAN MICROSCOPICAL SOCIETY

TREASURER’S REPORT

FROM OCTOBER 15, 1901, TO NOVEMBER 24, 1902

To Membership dues, 1890. .......ccsccccccccscesscccscese § 200

To Mentherahip Guts, 2900. oc vs ons bc0'0b olcedewessyesewumeee 6 00

To Membership dues, 1901. ......ccccccccceccscesccecsesss 3200

To Mensberahig diet, 1908. o0.000sgb06actocecccescabenennen 306 00

To Moemborahig Gadd, 1903. os caseniseces susessecdecssons - 4000

To Admission fees, 1902........sscccsccecsccecceccesceecs § 21 OO

To Admfusion S606, 1906. 60) on sci dee dece bckewsesbeeseeee ee

To Subscribers, Vol. XXI.........ccccccccccccccccesceess § 400

To Subscribers, Vol. XEID. «200 stdinsssteiccdeds eh'd Gaile 14 00

Te Sabscsibors,;: Vol.. AIEEE. cis ons tinbicitvactacsvpaensaen

54 00

To Advertising, Vol. XKIL. op wccnicccevcdcushicces conebasaectet aa

Teo Advertioing, Vol. XA TTE co ccncncisnvccinienaaseneeeucans ieee

To, Velemnes Wa. 4 ciccidcuand sasetddubiussdeceisesee

TO Balatien Gas Teenie. oss cape ccedcssccncevesave

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By Pantene, Secretary eas vcicc ve cocccainescae ob sds ebabeeeen . $ 22 70

it Pastas, TOCRNTOE « oc.cs cs 0acaninsccs sceuensakaedees 10 00

Dy Exprassnan, Secretary. s.occe ccninnccvccusnssiohsveuses $41 38

By Expressage, Treasurer........ mays I 40

By Stationery, Secretary .. $ 25 50

By’ Stationary, TrehsWeet soc occ 'c ccicscs cc ccncdbccténivccnss 10 25

By Typewriting, Secretary wi

By. Semticien, Sacnety indices dane cdabsveonececnecduccivgen $ 12 00

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By Printing Vol. XXIII. ..........s.seecccsecceecescesees $490 OO

By Plates ‘Vol, "KAUR. oc oc ices sccecccsccssccusenaseccce: | aun

By Cash returned to Treasurer. ........ccecsccccccecccess

We hereby certify that we have examined the foregoing accounts,

and the

vouchers submitted therewith, and have found the same true and correct.

Roscoz Pounp,

Freperic E. CLEMENTS,

Auditing Committee.

TREASURER’S REPORT 179

ODIAN’S REPORT FOR YEAR ENDING JULY 1, 1902

Smee QRCGUNE: .. ..sccdcecavcccw’ badccaveus caves vos QRRbe 20

PUP E CESSES OOCOCOSOCOCOOCOCoCOCO CCC Ce TT CTT eT Te ee ee ee ee ere 93 24

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De ee 63 93

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tal amount BINDOE 6 06 <n ocas cencdsonccebees seanapliebashuckvce $i4i9 24

if . : ent Oe WA. 5s ssc cevuteekensess ut iadaneess $ 275 12

ANNUAL GROWTH

Increase

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Fees

: EER SREP EO SE POSES CCDC CO SES HLS DESD EE EE ODES ECCC~ BS ir

[Reeasecesevarsecssecscessccecscseassscsrersesers 275 12

a Pirrspurc, June 27, 1902.

“We, the undersigned, hereby certify that we have carefully examined the

gcee of the Custodian as given in the foregoing report, compared the same

_ with vouchers, and found the same to correspond and to be correct.

4 M. J. Exnzon,

F. E. Ives,

Auditing Committee.

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CONSTITUTION

a Articte I

SIETY. Its object shall be the encouragement of microscopical

jorary members may also be elected by the Society on nomina-

ee Commer.

Articce III

is of Grle- Society shall conalat of President and two

= who shall hold their office for one year, and shall

zation: hs cainten a» eadchion doth tn aaa ae a

ee ee ee

& ee society, sas eek holed te ae ee, and the past

. re 's of the Society and of the American Society of Micro-

eitio’ still retin mentberthip tn this Sotiéty.

Articie VI

et eto os Rates ome eR

se of meeting and manage the general affairs of the Society.

182 CONSTITUTION AND BY-LAWS

Articie VII

The initiation fee shall be $3, and the dues shall be $2 annually, |

payable in advance. But any person duly elected may, upon pay- |

ment of $50 at one time, become a life member, entitled to all the

privileges of membership, but exempt from further dues and fees.

Articte VIII

The election of officers shall be by ballot.

ArticLte IX :

Amendments to the Constitution may be made by a two-thirds |

vote of all members present at any annual meeting, after having

been proposed at the preceding annual meeting.

BY-LAWS

Articie I

The Executive Committee shall, before the close of the annual

meeting for which they are elected, examine the papers presented

and decide upon their publication or otherwise dispose of them.

All papers accepted for publication must be completed by the

authors and placed in the hands of the Secretary by October 1st

succeeding the meeting.

Articre II

The Secretary shall edit and publish the papers accepted with the

necessary illustrations.

Articte III

The number of copies of Proceedings of any meeting shall be de-

cided at that meeting. But if not decided, the Secretary shall,

unless otherwise ordered by the Executive Committee, print the

same number as for the preceding year.

ArticLe IV i

No applicant shall be considered a member until he has paid his

dues. Any member failing to pay his dues for two consecutive

years, and after two written notifications from the Treasurer, shall

be dropped from the roll, with the privilege of reinstatement at any

time on payment of all arrears. The Proceedings shall not be sent

to any member whose dues are unpaid.

CONSTITUTION AND BY-LAWS 183

Articte V

Tt est caliedin' shall Ger WaAA. dc es snmeeines a Gn lest

Bi of the rccing Their term of office shall commence at

Articte VI

lidates for office shall be nominated by a committee of five

embers of the Society. This committee shall be elected by a

urality vote, by ballot, after free nomination, on the second day

of the annual meeting.

a Articte VII

icine or rescletions relating to the business of the Society

viel | be referred for consideration to the Executive Committee

ore discussion and final action by the Society.

Articte VIII

| of this Society shall have the privilege of enroling mem-

_ encouragement of research, but the apportionment of the sum thus

_ set apart shall be made by the Executive Committee.

"The Spencer-Tolles Fund Committee shall also have general

___ charge of the expenditure of such money as may be apportioned,

under the conditions laid down by the Society for its use.

‘The Custodian shall be an ¢x-officio member of this committee.

= Articte X

$ IT cssis’sCosetabunnts ddl husw tae dosiees' todeedl’ te ai

point two members to represent the Society on the Council of the

American Association for the Advancement of Science, in accord-

ance with the regulations of the latter organization.

Revised by the Society, June 27, 1902.

LIST OF MEMBERS.

LIFE MEMBER

HONORARY MEMBERS

5 Landsdowne Road, Notting Hill, London, England

Rev. W. H, FRS, FRMS.

Ingleside, Lee, S. E., London, England

_ CT. A.M., LL.D., F.R.MLS.,

Hillside, Clarence Road, Shanklin, Isle of Wight, England

R. L, M.D. Hon. F.R.M.S. (died May 11, 1902),

. England

p, R. Harste, AM, MD. FRMS........3 Fourth St, Troy, N. ¥.

MEMBERS

¢ figures denote the year of the member's election, except '78, which

ts an original member. Tae TRANSACTIONS are not sent to members in

E. Marues, E.. M.D.

J Mayrwato, F. J

Ecuevesnta, Exmso, M.D. Mercay, Haver, Pa.D.

Feacuson, Meave, Pu.D. Micnener, Ava, M.D.

ALreep Peaase, A. S.

Joux, M.D. Powers, J. H., Pa.D.

Ss. Srey, E. R.

E. Warr, Cuas. H., M.D

Rosert, M.D., "82 P 327 James St., Syracuse, N. Y.

Water W., M.D., '94.......949 T St., N. W., Washington, D. C

ALL, Joun, M.A., ‘oo cnnobps -Newburg, N. Y.

S., "79 pa Highlands P. O., Monmouth Co. N. J.

i. 16 Seneca Parkway, Rochester, N. Y.

Avaker S.,

186 AMERICAN MICROSCOPICAL SOCIETY

Bartiett, Cuartes Josern, M.D., dca it ciated 150 York St., New Haven, Conn.

Bauscu, Epwarp, '78......... a St. Paul St., Rochester, N. Y.

Bauscu, Henry, ee, ca sae . .Rochester, N. Y.

Manon, Wasser: GB... s 6c. cccaukasebeass St. Paul St, Rochester, N. Y.

Beat, Pror. James Hartiey, '96.. sseeeeeeeee9Ci0 College, Scio, Ohio

Bearpsiey, Pror. A. E., SP. vcs ueteu cet tae Tenth St., Greeley, Colo.

Beit, Crarx, Esg., LL.D., ’g2.. .-39 Broadway, New York City

Bennett, Henry C., ’93.. Boutth Fiat, 1692 ee New York City

Berinc, J. Epwarp, ’99.. Bay .-Decatur, Ill.

Bessey, Pror. CHARLES Eowm, PhD. LLD., "68... a ib en doc eae Linetin Neb.

Beyer, Pror. Geo. E., '99.. .-Tulane University, New Orleans, La.

Birce, Pror. E. A., S.D., 0p... .>.,ikialverley of Wisconsin, Madison, Wis.

Biscor, Pror. Tuomas D., ’ol..............--404 Front St., Marietta, Ohio

Buems, A. M., M.D., 81.............Ohio State University, Columbus, Ohio

Bovine, Pror. Donavpson, bot W. Main St., Crawfordsville, Ind.

Boorn, Mary A., F.R.M.S., 82.........60 Dartmouth St., Springfield, Mass.

Boyer, C. S., A.M., ’92 . .3223 Clifford St. Philadelphia, Pa.

Baspant, Gao, SWS. osc dcivwstecsdacusask vances taeriinereeee .Oil City, Pa.

Bromuey, Rozert Innis, M.D., ’93.............Washington St., Sonora, Cal.

Brown, N. HOwLann, 'Ol.........c00es00 33 S. Tenth St., Philadelphia, Pa.

Brunpace, A. H., M.D., ’o4............1073 Bushwick Ave., Brooklyn, N. Y.

Butt, James Epcar, Esg., ’92................141 Broadway, New York City

Burcwarp, E. A., M.D., ’99..........6 Elm St., Lodi, San Joaquin Co., Cal.

Burner, NatHan L., M.D., '96,

oma yer Chemical Co., Saginaw, W. S., Mich.

Burr, Pror. T. J., Ph.D., '78.. ..Urbana, Til.

Burt, Pror. Epwarp Spat Ph.D., ‘ot... + - Middlebury College, Middlebury, Vt.

Bytes, D. E., ’o2.. oe nd ..114 W. Second St., Oil City, Pa.

Carpenter, Tuos. B., M.D., ’99,............533 Franklin St., Buffalo, N. Y.

Carter, Joun E., '86..Knox and Coulter Sts., Germantown, Philadelphia, Pa.

Crark, Gayiorp P., M.D., ’96..........619 W. Genesee St., Syracuse, N. Y..

Crark, Georce Epw., M.D., ’96...........Skaneateles, Onondaga Co., N. Y.

Ciements, Freperic E., A.M., Ph.D., ’98,

University of Nebraska, Lincoln, Neb.

Coste, A; Ji, GBsinui . University of Nebraska, Lincoln, Neb.

Cocks, Pror. Reonat> S., "90. . .-MeDonogh High School, New Orleans, La.

Corrin, Ropert, ’00............- .. Bedford City, Bedford Co., Va.

Coorg, A. F., M.D., ’86.. sacmene .-114 Sycamore St., Oil City, Pa.

Coucn, Francis G., 86,

Kalish Pharmacy, 100 E. Twenty-third St., New York City -

Con, Cuas ¥., PRS. i i tee Grand Central Station, New York City

Caam, TeOMas, Eis es cectactsnsaase 1013 Sherbrooke St., Montreal, Canada

Daven, Curae. Bi, Bs co ukace i chesdasessedes Drawer 1033, Rochester, N. Y.

Davis, F. L., M.D., ’99.. ..209 Locust St., Evansville, Ind.

Dissrow, Wiiuram S., MD. “PRG. a eae 151 Orchard St., Newark, N. J.

Aurnun H, et. en .4 Irving Place, New York City

B.S., A.M., Ph.D., 98,

Nebraska Wesleyan University, University Place, Neb.

4 South Ave, Ithaca, N. Y.

ea:

bet

eee

SEE=

ee F

. Wea ackonnieabicen tort Webster St, San Francisco,

i" F.R.MS., "79..........State and Second Sts, Troy, N.

‘Harri, Joun J. B., B2............333 N. Arsenal Ave. Indianapolis,

188 AMERICAN MICROSCOPICAL SOCIETY

Hicorns, F. W., M.D., '98.. , -..20 Court St., Cortland, N. Y.

Hn, Hexeeat M, PhD., 8... ..24 High St. Buffalo, N. Y.

Hutton, Daviw Ciark, A.M., MD., ' ‘ol. mrt S. Campbell Ave., Chicago, IIL

Horrman, Jos. H., M.D., '96.. -111 Steuben St., Pittsburg, Pa.

Hotus, Freverick S., oo 'p..+-Yale Medical School, New Haven, Conn.

Houmes, A. M., M.D., a ..205 Jackson Block, Denver, Colo.

Hoskins, W., '79... --Room 5, 8 S. Clark St, Chieago, I

Howe, W. T. H., Ph.D., "00. . Pe . Evansville, Ind.

Howtanp, Henry R., A.M., ‘08. . a7 Sumaser: St, Buffalo, N. Y.

Humpnrey, Pror. O. D., Ph.D., 19s... "State Normal School, Jamaica, N. Y.

Hyatt, J. D., '78...........+.+.+.-.-69 Burling Lane, New Rochelle, N. Y.

Ives, Freveric E., 02........0000s 550 W. Twenty-fifth St. New York City

Jacxson, Danret Dana, B.S., ’99........- 941 President St., Brooklyn, N. Y.

James, Franx L., Ph.D., M.D., ’82........514 Century Bldg., St. Louis, Mo.

James, Geo. W., ’92.. KK ..108 Lake St., Chicago, Ill.

Jounson, Franx S., MD., FRMS, "93. « gaat Prairie Ave., Chicago, Ill.

Jounson, Wm. D., M.D., '98.. o 0c cede on 0 ARO ERE eR

Jones, Mrs. Mary A. Drxon, MD. FRMS, 98,

249 E. Eighty-sixth St., New York City

Jupay, CHANCEY, '00...........+.45+2++++++++-720 Marine St. Boulder, Cal.

Ketroce, J. H., M.D., ’78.. ep wpe ..Battle Creek, Mich.

Kerr, Apram Tucker, Jr, MD., 19s. pps ee BE a Waite Ave., Ithaca, N. Y.

Krncssury, Beny. F., A.B., bays spre ..125 Dryden Road, Ithaca, N. Y.

Krntey, Jos. B., M.D., ‘or. ey Sar Welton St., Denver, Colo.

Krexpatrick, T. J., 93...- -sseeee++-701 E. High St., Springfield, Ohio

Koromw, Cuartes A., PLD. "90. bib dks University of California, Berkeley, Cal.

Korz, A. L., M.D., ’or.. &. . .32 S. Fourth St., Easton, Pa.

Krarrt, WILLIAM, 95. . att Ww. Fifty-ninth St., New York City

Krauss, Wa. C., B.S., MD., "90... ..479 Delaware Ave., Buffalo, N. Y.

Kueune, F. W., "79. . anda nner Court St., Fort Wayne, Ind.

Lams, J. Mervin, M.D., ’or........-.. gio T St. N. W., Washington, D. C.

LatHamM, Miss V. A., M.D., D.D.S., F.R.MLS., '88,

88 Morne Ave, Ropes ea

Lawton, Epwarp P., ’88.. Ay ..3 Linden Ave., Troy, N. Y.

Lewre, J. Harry, '96.. us . .336 Pine St., Reading, Pa.

Lewis, Mrs. Kienhaine 'B, 8. 3 * Bimstone,” 656 Seventh St., Buffalo, N. Y.

Lewis, Ira W., '87.. : Lee ..+.---408 S. Galena St., Dixon, TIL

Locke, Joun D., 193, . ial paid i P.O. Box 129, Haverhill, N. H. |

Lown, Anotams 300, ic isis ciatds 4 sawewseite 8 Clinton Place, Rochester, N. Y.

Looms, Henry, * he .-48 Clinton Place, Rochester, N. Y.

Loomis, CHANvLER H., 7... , Atlantic Dredging Co., 31 Pine St., N. Y. City

Love, Pror. E. G., F.R.M.S., ’o1........ 8 E. Fifty-fifth St, New York City

Lyman, R. A., A.M, ’or.............++++++--120§ Pacific St, Omaha, Neb.

Lyon, Howarp N., M.D., ’84..............828 Wheaton Ave., Wheaton, Ill.

P., M.D., 85 32 W. Adams Ave., Detroit, Mich.

P., M_D., ‘or ..-.-1828 Fifth Ave. Troy, N. Y.

Couurws, M.D., beg 2507 Penn. Ave., Washington, D. C.

Maxsuau, Wx., Jn, '92... . Coudersport, Pa.

STER: Euose E, ‘oy. Rural Mail Delivery No. 2, New London, Ohio

ATues, E., M.D., Ph.D., ‘oz. ....80 Park Place, East, Detroit, Mich.

Yrrenp, Frevericx J., ‘o2 1038 Seventy-second St., Brooklyn, N. Y.

¥, Joseru, "84 s+seee++289 Eighth St., Troy, N. Y.

Rev. Hastert, 85 -.-9 W. Forty-eighth St, New York City

R. M., M.D., ‘oo -35 Twentieth St, Wheeling, W. Va.

ee Pn . 2651 Gilbert Ave., Cincinnati, Ohio

Cuas. C., 85... -+«++-$19 Fifth Ave, Pittsburg, Pa.

A. Curros, M.D., “FRMS, 8,

hha 324 Montgomery St., Syracuse, N. Y.

Mom, Famenck W., MD., FRMS. %3.. .2540 Prairie Ave., Chicago,

Athens, Ohio

College, S. C.

Geneva, IIL

Mas. C. S., ‘or. «+++++1544 Franklin St., Denver, Colo.

Joux A, PhD. FRMS, '®... ..44 Lewis Block, Buffalo, N. Y.

eligi «ss cvas 988 Highlond Ave, Pittsburg, Pa.

J. H., Sx, ‘or -ssseeeeeesessesBure Block, Lincoln, Neb.

Rosexr O., M.D., 'o1......Hearst Anatomica! Laboratory,

University of California, San Francisco, Cal.

Myexs, Buxton, D., '97 : ...89 N. Tioga St. Ithaca, N. Y.

_ WNouww, Ricwanp J., M.D., 83.................---§ York St, Savannah, Ga.

Oxare:, T. E., M.D., 'o92............Med. Dept. Univ. of Ga. Augusta, Ga.

Onuex, W. H., ‘or oe sncenceccececcsceese38 Locust St. Portland, Me

Otsex, Auraxzo Bexrue, M.D., '96 .... Sanitarium, Battle Creek, Mich.

Parx, Rosweit, A.M., M.D., '94..........§10 Delaware Ave., Buffalo, N. Y.

Panxer, Horatio N., '99..................Board of Health, Montclair, N. J.

Paruicx, Frawx, Ph.D. or.................-6ot Kansas Ave, Topeka, Kan.

Axruvusr S., B.Sc. ‘o2.....2623 N. Twenty-fourth St, Omaha, Neb.

Frmp N., 7... .. 6. sccececsceceeeeessstQ07 Third Ave, Altoona, Pa.

Rey Pore . «. «9609 Woodland Ave., Philadelphia, Pa.

mu, Macwus, Esq, 'ot.. ..440 Diamond St, Pittsburg, Pa.

nos., Esg., ‘97. 243 Superior St. Cleveland, Ohio

Roscor, A.M., Ph.D, '98.. $6 00s cebecuctad ce teeOeey, DOU

Jas. H., A.B. Ph.D., ‘oa .-»-Doane College, Crete, Neb.

19° AMERICAN MICROSCOPICAL SOCIETY

Ransom, Brayton H., ..1362 B St., S. W., Washington, D. C.

Reep, Raymonp C., PLB. DVM, 199. . .120 W. Hudson St., Elmira, N. Y.

Reysurn, Ronert, M.D., ‘90. . 1.2109 F St, N. W., Washington, D.C.

Ricwarps, Extas, an ..1722 Calhoun St., New Orleans, La.

Sampson, Atten W., M.D., '96.......00000esccceeeseeceeesFPenn Yan, N. ¥.

Sarcar, Hem Cuunpra, M.B., ’or,

| Rajamundry, District Godawari, India

Scnoney, L., M.D., ’98. . ; ..23 W. 135th St. New York City

Seaman, Wm. H., M.D., "86... - -1424 Eleventh St, N. W. Washington, D. C.

Seawet, Beny. Lee, B.S. (Edin.) ‘or. .308 E. Grover St., Warrensburg, Mo.

Smanus, S. Gy MLD., "00% seiccs i ivideae avec 547 Clinton Ave., Albany, N. Y.

Suearer, J. B., '88................+.+++-+.-809 Adams St. Bay City, Mich.

Suuttz, Cuas. S., '82.............++..-Seventh St. Docks, Hoboken, N. J.

Genewy, T. Ries 3 daccdccccacsa trees eae go2 Pine St., Philadelphia, Pa.

Sremon, Rupowpn, 91. --195 Calhoun St., Fort Wayne, Ind.

Stocum, Cuas. E., Ph.D., “MD, 8... & ..Defiance, Ohio

Sint, 3. CB MGs ci ccectek ctsau eae 132 "Carondelet St, New Orleans, La.

Sraurrer, Rev. T. F., ’or................200 Eleventh St., Sioux City, Iowa

Srezsins, J. H., Jr, Ph.D., MD: cee Madison Ave., New York City

StepMAN, Pror. J. M., ’95..........Mo. Experiment Station, Columbia, Mo.

Stoney, Ropert J., Jr, ’96............++.++++-424 Fifth Ave. Pittsburg, Pa.

Summum, Pole. HER, G6. iis ccccccsSocbcoveckctececkseaee ..Ames, Iowa

Taytor, Geo. C., LL_D., ’99.. ...-Poydras, St. Bernard Parish, La.

Tuomas, Artuur H., '99. . . Twelfth and Walnut Sts., Philadelphia, Pa

Tomas, Pror. Mason B., 190. veebpaeenle College Campus, Crawfordsville, Ind

Trams, Gronak, "96. 2... cc cc cecececds 1410 E. Genesee St., Syracuse, N. Y.

Twtninc, Frepenick E., '96.............0-- 29 Patterson Block, Fresno, Cal.

Uxaicu, Cart J., B.S., ’or...............Central High School, Duluth, Minn.

Vanpverport, Frank, M.E., Ph.D., Mes .-153 Center St., Orange, N. J.

Verver, M. A., M.D., 85... ; . 12 Queen St., Lyons, N. Y.

VrevensurcH, E. H., ’84....... 60 Plymouth Ave., Rochester, N. Y.

Warp, Henry B., A.M., Ph.D., ’87....University of Nebraska, Lincoln, Neb.

Wener, Pror. Henry A., Ph.D., ’86......1342 Forsyth Ave., Columbus, Ohio

Weeks, Joun Rockwett, ’99..................Weather Bureau, Macon, Ga.

WeicutTman, Cuas. H., '86................5859 Michigan Ave., Chicago Ill. -

Wetcu, Geo. O., M.D., ’ol...........+++-+--.-Box 416, Fergus Falls, Minn.

WELLINGTON, CHARLES, '90.......---+00005 403 Pringle Ave., Jackson, Mich.

Wenpe, Ernest, M.D., rae ’91......471 Delaware Ave, Buffalo, N. Y.

Wueeter, E. J., Ph.D., ’oo. .-79 Chapel St., Albany, N. Y.

Wuetrtey, H. M., MD. PhG., FRMS., "90,

2342 Albion Place, St. Louis, Mo.

LIST OF MEMBERS 1g!

OD.-..+++++.-Director Mt. Prospect Laboratory,

pes Flatbush Ave. and E. Parkway, Brooklyn, N. Y.

= iH, M.D. RP ee me Sandwich, N. H.

es D., M.D., F.R.M.S,, '85.....405 S. Main St., Petersburg, Ill.

SUBSCRIBERS

Paste LaMARE ss viicddecucdeteutddstcetdectesen Detroit, Mich., one copy

Frecp COLUMBIAN MUSEUM.........0+s++000+ee00+++-Chicago, IIL, one copy

Cotumpia University Liprary.. ER alee York City, one copy

New Yorx Pusiic Luprary.. ..New York City, one copy

Dutau & Co... .. «37 Sobo Square, London, England, 4we eueies

CARNEGIE Limmany. k iid dite dielde dadinee a eecewa phan Pittsburg, Pa., one copy

Syracuse Centrat Liprary.. . Syracuse, N. Y., one copy

AcaApeMY oF NATURAL Scummcas.. Soon ‘juan, "Philadelphia, Pa., one copy

New York AcADEMY OF MEDICINE,

17 W. Forty-third St., New York City, one copy

Tae Missourt Botanica GARDEN.............++++ St. Louis, Mo., one copy

Screntiric Lrprary......... U. S. Patent Office, Washington, D. C., one copy

N. Y. State Verertnary Correce, Cornell University, Ithaca, N. Y., one copy

U. S. Meprca Museum anp Liprary,

Surgeon General's Office, Washington, D. C., one copy

New York State Liprary...........Serial Section, Albany, N. Y., one copy

Boston Society or Naturat History. .Berkeley St., Boston, Mass., one copy

Dr Jos. H. Linsey,

Director of Hygienic Laboratory, Burlington, Vt., one copy

Limrary oF THE Onto State University..........Columbus, Ohio, one copy

Laporatory OF HisToLocy AND EMBRYOLOGY,

University of ek ore Minn., one copy

Lrprary or THE University oF NEBRASKA... .-Lincoln, Neb., one copy

Joun Crerar Lrprary.. a ..Chicago, IIL, one copy

LiprarRY OF THE Tnzzmess ‘Srare Lanonarony « or ) Navonat History,

Urbana, IIl., one copy

New Hampsuire State Liprary........--000000 Concord, N. H., one copy

Mepicat Liprary............McGill University, Montreal, Canada, one copy

S. C. Futrer.........Westboro Insane Hospital, Westboro, Mass., one copy

Lrerary or THE CoLorapo STATE ran TOME eI Colo., one copy

Liprary oF THE UNIVERSITY OF MONTANA.. ...Missoula, Mont., one copy

Pustic Liprary.. re «+eeeeeesPlainfield, N. J., one copy

San Francisco MicnoscoPICAL Socterr. . ....San Francisco, Cal., one copy

Liprary OF THE UNIVERSITY OF Wisconsin. cpeacanens Madison, Wis., one copy

Liprary oF THE STATE NORMAL.........--0000+ Warrensburg, Mo., one copy

BIENNIAL INDEX

For Votumes XXIII ann XXIV’*

Some Points in the Structure of the, H. W. Graybill.. 191

i erican Microscopy, The Debt of, to Spencer and Tolles, W. C. Krauss 19

n ae Oicygen 20d Carbonic

I< as esaeccccdhescvcecoctudeddcs sagunneecbscedwartencie 49

Mie i Ths Suess, cos Gussaale ok Gone

Sie weviion of the Sanitios unt & tuattangianiat, Ot vie Bort

Sse: Charles E, Evolution in Microscopie Plant... ..... eseseses SS

ree ee ee ee ree ee ee ee

; wuian Movement, Prevention of, in Milk or other Liquids with

My Mir Objects in Suspension, Simon H. Gage............... 21

ees. SE as cy Somes noe Onan be

ty ota itis Wis ee Ganda We Kote. . 173

Scncaon of Hynrely, On Homncley carlete (Magalhaes) and

and @ rearrangement of the North American genera, Charles E.

ae B ok

- I< c.: vicisissciiec Fin sik % conan ce Mame

gt Marrangement of the North American genera, Charles E. Bessey. 27

E. W., Obituary Sketch of, Robert O. Moody. . eee

ia Entomostraca, Notes on, A. E. Beardsley... ..........6.00005 at

| Nelrado Protozoa, Notes on, with descriptions of new species, A.

E. Beardsley .

a “SConjagatae, The Structure and Classification of the, with a revision of

oe es set 8 ee ee ea

__Charles E. Bessey. . “2 . 45

ii ictiscsees to Volume XXIII are starred.

194 INDEX

Connecticut, Two Growths of C heraneriery ts in, Frederick S. + 13

*Constitution and By-Laws.. : ; ; . 283

Constitution and By-Laws. . . 8

*Contribution to the Suitervenana’ Pans ‘a ‘Temas, me c J. ‘Ulrich. . ota: wae

Crenothriz, A New Species of (C. manganifera), D. D. Jackson........ 3f

Cultural Studies of a Nematode associated with Plant Decay, Haves

Metcalf . os openckan ae

*Curvipes, The ‘North American. Secclen oy Robert H. Wolcott. . . 201

*Custodian’s Report, B9007OE. oc0cecch csedeb bees bichsvannaanene Mere 282

Custodian’s Report, 190I-2........ becte choco’ edbsbeceneneene enna - 179

Data for the Determination of Human Entozoa, Henry B. Ward........ 103

*Debt of American Microscopy to Spencer and Tolles, The, W. C. Krauss 19

*Eel Question, The Solution of the, C. H. Eigenmann. . ixek ae

*Effect of Oxygen and Carbonic Acid Dissolved in Natural Waters pans

the Occurrence of nein rae > eee

N. Parker.. ocees beveaen mee

*Eigenmann, Carl H., " ‘The Solution of the Eel Question. . PTE Ey hie

*Eirod, M. J, A New Hy ress icccecccssesccccasecssscousensaee 257

*Embryologic Laboratory, Modification of some Standard ao to

facilitate the Work of the, Simon H. Gage.. - 259

*Endothelium, The Morphogenesis of the Stigmata pe Stomata. occur

ring in Peritoneal and Vascular, A. E. Hertzler. . o ong eeabeenrieee

*Entomostraca, Notes on Colorado, A. E. Beardsley................ ene

Entozoa, Human, Data for the Determination of, Henry B. Ward.... 103

Evolution in Microscopic Plants, Charles E. Bessey. . Peery Ae

*Fauna, Subterranean of Texas, A Contribution to the, rod J. ‘Ulrich... 83

*Gage, Simon Henry, Modification of some Standard Apparatus to facili-

tate the Work of the Histologic and Embryologic Laboratory... ... 259

*Gage, Simon Henry, Laboratory Photographic Apparatus............ 263

Gage, Simon Henry, Prevention of the Pedetic or Brownian Movement

in Milk or other Liquids with Minute Objects in Suspension........ 21

*Gases, Dissolved in Natural Waters, Effect of Oxygen and Carbonic

her gente wisgidor signe sion wets seamnreh C. Whipple

and H. N. Parker... we

*Graybill, H. W., Some Points i in ‘the ‘Berectere pr the Acanthooatialas . Ig

*Hertzler, Arthur E., The Morphogenesis of the Stigmata and Stomata

occurring in Peritoneal and Vascular Endothelium. . ee

Hilton, David C., The Early Morphogenesis and Histogeneals ‘of the

Liver in Sus scrofa domesticus, including notes on the Morphogen-

esis of the Ventral Pancreas..

Histogenesis of the Liver in Sus scrofa ‘fomesticns, ‘The Basis, David

Cc Hilton . * vee ewe eee 55

* Histologic tchoestos: Modification of some Stendand “Apperatus to

facilitate the Work of the, Simon H. Gage. . ovegetnee

Hollis, Frederick S., Two Growths of Chlensdomenans in 1 Connections 13

Human Entozoa, Data for the Determination $32 caret B. Ward........ 103

*Hydra, A New, M. J. Elrod.. Porck ate é RS

INDEX 195

| Hiymenoleps carioca (Magalhaes) and Hymenolepis megalops (Nitzsch)

. with remarks on the Classification of the Group, On, B. H. Ransom 151

Mfodiane, Lake Maxinkuckee, The Plankton of, Chancey Juday........ 61

mn. Stereoscopic Photomicrograghy with High Powers. ... Prey

“Jackson, D. D., A New Species of Crenothrix (C. mangamifera)........ 31

_ *Juday, Chancey, The Plankton of Lake Maxinkuckee, Indiana.......... 61

7 ere ce rintoce ot Late Minkehesten Indiots.......

__ Tolles seeees Steen ee ee en eeeeeneeeees seen ness sesaesnseeeseensenes 19

“Laboratory, Modification of some Standard Apparatus to facilitate the

__ Work of the Histologic and Embryologic, Simon H. Gage sevkasices 259

“Lake Maxinkuckee, Indiana, The Plankton of, Chancey Juday 61

Liver, The Early Morphogenesis and Histogenesis of, in Sus scrofa

_ __ domesticus, David C. Hilton..... a

“Lyman, Rufus Ashley, Studies on the Genus Cittotaenia f 173

one Lake, Indiana, The Plankton of, Chancey Juday 61

_ *Members, List of, 1901 jidacusscuuees 287

ee (omen List of, 1902..

. Metcalf, Haven, Cultural Studies of a Nematode associated with Plant

Raha ieawnapartate ssn pe

*Microscopic Organisms, The Effect of Oxygen and Carbonic Acid Dis-

solved in Natural Waters upon the Occurrence of, G. C. Whipple

Microscopic Plants, Evolution in, Charles E. Bessey................+-

*Microscopy, The Debt of American, to Spencer and Tolles, W. C. Krauss 19

Milk, Prevention of Pedetic or Brownian Movement in, Simon H. Gage 21

*Minutes of Twenty-fourth Annual Meeting 275

Minutes of the Twenty-fifth Annual Meeting 171

Minutes of the Mid-Winter Meeting, January, 1903

seer neds newer

POPP POC Pee Pee eee eT eT

ne Vee Sees ee eee Notes

on, David C. Hilton... .

Necrology, Charles M. Vorce, R. H. Ward...

Nematode, Cultural Stodies of a, amociated with Plant Decay, } ‘Haven

Metcalf . Gide ae

196 INDEX

*New Species of Crenothrix (C. manganifera), A, D. D. Jackson...... 31

*North American genera of Conjugatae, a erage tae of the, Charles _

E. Bessey . teen eeee 145

North Ametione qenern of Phseomeaetns, oy cenmepnneeds of the,

Charles E, Bassey. ane. os ovcetésenves pasnbusees dambeals clack enwsi 2

*North American Species of Curvipes, The, Robert H. Wolcott.......... 201

North American Species of Limnesia, The, Robert H. Wolcott.......... 130 |

*Notes on Colorado Entomostraca, A. E. Beardsley. . ee J

*Notes on Colorado Protozoa, with ire eesti of Mew: ‘Species, A. E.

Beardsley ....... oc enqect auos 46s @mCnmn ane

*Obituary of E. W. Claypole, Robert 0. Moody... 0606's 6» alee

Obituary of Charles M. Vorce, R. H. Ward.. oo 0 Keietle Meee

*Occurrence of Microscopic Orgeatenss, the EiSect af Oxoaenanaiiae

bonic Acid Dissolved in Natural Waters upon the, G. C. Whipple and

H. N. Parker. . . ee eee ee ee ee eo 103

*Officers for 1900-Ol, ‘ond Sauedlve " Comsmniiten... deleie'e » 6m bid Ab Sanna

Officers for 1901-02, and Executive Committee. . wert

*Oxygen, On the Amount of, Dissolved in Natural ‘Waters, aa the Effect

upon the Occurrence of Saninalivioa: aie hie G. C. Whipple and

H. N. Parker.. ‘ Sere

Pancreas, Ventral, Notes on 5 Mornbcosendle ey in Sa pain domesticus,

David Cc. Hilton... eer eeeeeeee 55

a a

*Parker, Horatio N., al Whipple, George C, On ‘the ‘Amount of Oxygen

and Carbonic Acid Dissolved in Natural Waters and the Effect of

these Gases on the Occurrence of Microscopic Organisms.......... 103

Pedetic or Brownian Movement, Prevention of, in Milk or other Liquids

with Minute Objects in Suspension, Simon H. Gage. . o o.he hae ne

*Photographic Apparatus, Laboratory, Simon H. Gage. . «wawtanapieeiene

Photomicrography, Stereoscopic, with High Powers, F. Ez Teees spite ani aeee

Phycomycetes, The Structure and Classification of, with a revision of

the families and a rearrangement of the North American genera,

Charles E. Bessey. . reer

Pig, The Early Morphoascents and ‘Histomenasia of the ‘Liver, including

Notes on the Morphogenesis of the Ventral Pancreas, David C.Hilton

Plankton, A Method of Concentrating, without Net or Filter, B. L.

Seawell. o..<s es o 3a: ease

*Plankton of Lake WMaxtokuckes, Indiana, The, ‘Chancey Judey... omadewt

Plant Decay, Cultural Studies of a Nematode associated with, Haven

Metcalf .....ccicscccsccusledeshh dalies secand¥eesnduieheeauee ovaads

*President’s Address, 1901.. » 0.05 4040 gatls Ohe thease chi ban be

President’s Address, 10902... o neeue bs ude 00 hips oe'> sicnantek ie te

Prevention of the Pedetic or Brownian Movement in Milk or : cahen

Liquids with Minute Objects in Suspension, Simon H. Gage.....

*Protozoa, Notes on Colorado, with aneeTone of New Species, - E

Beardsley ...... bdemets

*Ransom, B. H., On Homenolepis ¢ carioca ; (Magathees) oa " Hymenolebis

megalops (Nitzsch) with remarks on the Classification of the Group 151

er ee

INDEX 197

A Method of Concentrating Plankton without Net or

eer-Tolles Fund, Reports. occ aces sssseenceeeee

reoscopic Photomicrography with High Powers, F. E. Ives...

ee Sone Tele Oe 191

re of the Conjugatae, The, Charles E. Bessey... ddtddak

cof the Phycomycetes, The, Charles E. Bessey... véebacea

( on the Genus Cittotoenia, B. A. Lyman. . oc un os bsdaneuee

Buse

List of, 1902. . Fa eg

Tre Report, 1901-02. .

Silks of Chlonsdonsscs in Connecticut, Prodacids &. Helle...

Trick ‘Cari Jost, A Contribution to the Subterranean Fauna of Texas...

ree, Charles M., Obituary Sketch of, R. H. Ward... ..........0005+

Society

Orcanizep 1878 IncorrorATED 1891

MELD AT

WINONA LAKE, INDIANA, JULY 29, 30 anv 31, 1903

VOLUME XXV

| ; AND INDEX TO VOLUMES I TO XXV INCLUSIVE

194

cemetery: R. H. ‘Wendie sac ick sccbildek «<.kva denen Neb

St COGEEEB so vc vc ccadncuscscnvecssuebsseececs NO GOONER Le.

— MEMBERS OF THE EXECUTIVE COMMITTEE

aa eee adamealnd

‘Hvar, of New York Cit,

at Columbus, ©., 1881.

McCaita, Ph.D., of Fairfield, Ia,

at Chicago, Ill, 1883.

Burant, Ph.D., of Champaign, IIL,

oe at Chautauqua, N. Y., 1886.

E. Feu, M.D. F.R.MS., of Buffalo, N. Y.,

4 at Detroit, Mich., 1890.

x L. James, Ph.D., M_D., of St. Louis, Mo.

: at Washington, D. C., 1891.

D. Ewstt, M.D., of Chicago, IIL,

‘ at Rochester, N. Y., 1892.

mw Hewey Gace, B.S., of Ithaca, N. Y.,

z at Ithaca, N. Y., 1895.

Currromp Meaces, M.D., F.R.M.S., of Syracuse, N. Y.,

at Pittsburg, Pa. 1896.

_ Krauss, M.D., of Buffalo, N. Y.,

ee at Columbus, O., 1899.

at New York City, 1900.

at Denver, Col, 190.

‘et Phtherg, Pa, 1900

at Winona Lake, Ind., 1903.

s in its published Transactions unless endorsed by a special vote.

187

Bagh

TABLE OF CONTENTS fos.

FOR VOLUME XXV ae

ee The Annual Address of the President, The Thermocline and its Biological ah

Significance, by E. A. Birge, with Plates I and II.. 0 os véinebs) ae

The Finer Structure of the Heart Muscle of the Dog, wo Gertrude. A oy

Gillmore, with Plates TTT to Vissscciricccsdncccessccesecnan o obsee SER

_—- Additional Notes on the Cladocera of Nebraska, by Chas. Fordyce, with ies

Plate VI PTS TEVELUEELETE ETE ee eee eee Ra’

Upon the Occurrence of Haemosporidia in the Blood of Rana Catesbiana, =—

with an Account of their probable Life History, by Jas. H. Stebbins, Ce ieee

It. with Plates VII and VIII.. eee Tere ee ree ee mt

Outline of the Tube Plan of Structure ‘of the. Antaal Body, by J. a ee

Foote, with Plates IX to XIV.. ve scccsseveee OS

The Classification of Protophyta, Fociodion a ‘Revision: of the Families, =

and a Rearrangement of the North American Genera, by Chas. E._

Bessey Reece r ace w eens acres ee ceee sees esse esse ecesseesse s0spegenuen Le

_- River Pollution and Purification, by T. J. Burrill, with Plates XV to oe

o XVII CORR HR HEE HOHE TETHER EHH EEE EEE EE EEE EEE een eee ae

Synchaeta bicornis: A New Rotifier from the Brackish Waters-of Lake __

Pontchartrain, Louisiana, by J. C. Smith, with Plate XVIII........ 121

_. A Biological Reconnoissance of some Elevated Lakes in the Sierras and

a the Rockies, by Henry B. Ward, with Reports on the Copepoda by Hye

C. Dwight Marsh, and on the Cladocera by E. A. Birge, and with

Plates XIX to XXX.......cceeceesccecceccceacevcnssevseceesss soe S27

Necrology, Richard L. Maddox, with Plate............scccccsesssevsees 155

Bushrod ‘W. Jansen, with: Plates ois bcd s casissices cacesce seus onan Be

Oocar Cy Bo, with. FAst6 «sine okie sacnccdyswecs vi vinvabveck ambien oineieaee

J. Cy Millen, with | Pleti.vas os iccneccs tiated sss seh auasteshunsene <s bepen

Minutes of the Annual Meeting. .........2002:cccccccssessiescceb eae Pe

Minutes of the Mid-Winter Meeting ee ee eee nee 170

Custodian’s Report, Spencer-Tolles Fund............+.0++e0000% «06s b Ree

Treasurer's REQott occsacsevctacsvagss vb evsstedadsevertnics ste vevee 273

Comstitution .......sesecceesescecscccssesrcsesoussesceenseas weceeeens BIS.

By-Laws ciscocccccssncdtdabecsesacde coatake dave cause cde see ee

List of Members...... ghetuchsneynmloees tpbsisedskecenns nine peda: ae

List of Subscribers... .0isccatsccscussueeesy Uhsnabaelineeeneenne Jes cae

Index to Volumes I to XXV, Inclusive................. se vae pent chee

Adivertioememte® <.2oosccccsveavcsencadsy alse puue shee ens Pere

TRANSACTIONS

-SIXTH ANNUAL MEETING, HELD AT WINONA LAKE,

INDIANA, JULY 29, 30 AND 31, 1903

THE ANNUAL ADDRESS OF THE PRESIDENT

THE THERMOCLINE AND ITS BIOLOGICAL

SIGNIFICANCE

By E. A. BIRGE

It is my misfortune that my studies do not enable me to speak to

his Society on a subject which is immediately connected with its

mame. To me, as to many biologists, the microscope has been an

sid to work rather than an object of study in itself, and in pre-

an address which shall deal with a topic of general scientific

erest it has been necessary for me to select a subject which has

but little direct relation to the microscope, although that instru-

ment is the main aid to the student in working out the biological

problems which the subject presents. However, it is not inappropri-

ate that we should consider a topic relating to the biology of a lake

_ when we meet, as we do to-day, on the shore of a sheet of water at

once so beautiful and the subject of so much scientific investigation

hell geet ceteapsrorng dong dena

below the surface, in which the temperature falls rapidly—much

6 E. A. BIRGE

It is a well known fact that in summer the temperature of a fresh-

water lake is much higher at the surface than at the bottom. The

surface water may have a temperature anywhere from 20° to 30° C.,

while the bottom temperature varies in different lakes between 4° C.

in deep bodies of water—the temperature of the maximum density

of water—and a temperature very close to, or equal to that of the

surface, in large and shallow lakes. Ordinarily, however, the differ-

ence is considerable. In small lakes, even though they are but 10 m.

to 15 m. in depth, there is usually a temperature difference of 10° to

12° between the surface and the bottom.

When this fall of temperature is distributed to the several strata

of the water between surface and bottom, it is seen that the

decline is by no means uniform. Ordinarily there will be found a

surface stratum of water, varying in different lakes from 2 m. to 12

m. in thickness, whose temperature is very nearly that of the surface.

If at this season temperatures are taken in a lake like Winona in the

early morning, before the sun has had an opportunity to warm the

surface water, a stratum 5 m. to 6 m. in thickness may possess a tem-

perature almost absolutely uniform. Immediately below this stratum

comes another—the thermocline—in which the fall of temperature

is very marked and very rapid. The temperature usually declines

as much as 2° or 3° in the course of a meter and the fall may be

much more rapid than this. A drop of 5° or 7°, or even 9° has been

found in a single meter and in certain lakes a decline as great as

5° or 6° in the course of a meter may be ordinarily expected. This

stratum, the thermocline, varies in thickness in different lakes and

in the same lake under different circumstances, but may be from 2 m.

or 3 m. to 5 m. in thickness. Its upper surface is pretty sharply

marked and can usually be defined within the limits of a few deci-

meters. In its lower part, however, the thermocline passes more

or less gradually into the region below and it is not possible to mark

its lower surface by any exact level, though it is usually considered

as ending where the decline in temperature becomes less than 1° per

meter. Below the thermocline the rate of decline in temperature _

becomes rapidly smaller and soon amounts to only a few tenths of a ©

degree per meter. As the depth increases the change in temperature

becomes still less until perhaps, in the deepest lakes, the tempera-

ture of 4°, that of the maximum density of water, is reached, and

below this point there is no further change.

THE THERMOCLINE AND ITS SIGNIFICANCE 7

This distribution of temperature in various lakes is illustrated by

the following diagram (Plate I), which shows the distribution of

temperature in three Wisconsin lakes on May 30 and September 2,

1898. These lakes are Garvin—a small pond having an area of

about 8 hectares (20 acres) and a depth of about 11 m.; Okauchee

Lake with an area of 4.4 sq. km. (1.7 sq. mi.) and a depth of 27 m.;

and Lake Mendota, whose area is 39 sq. km. (15 sq. mi.) and whose

depth is slightly over 24 m. These lakes are in the same general

region; Garvin being immediately adjacent to Okaucnee Lake, and

both of these about 50 miles east of Lake Mendota. On May 30

Garvin Lake showed a strongly marked thermocline, whose upper

Surface lay at a depth of 4 m. and showed a fall of 7° in about

alf a meter. Okauchee Lake showed a thermocline extending

fom about 6 m. to 11 m., while Mendota on this date showed

that could fairly be called a thermocline. Thus the smallest

ec tee met Mert i Corvin. The wos

Began oh sepsis as chewed oe The

teed eowet on cogarat ionet c.°, which was probably due

.an irregular stratification of the water on the earlier date. Garvin

tiga i ee ees while Lake

- TT aster dintrfeniicn it tonigertnats: was Mike hatieil Tey

Simony in Germany over fifty years ago. His observations were

8 E. A. BIRGE

entirely forgotten and in 1885 Buchanan‘ observed the same phe-

nomena in Loch Lomond, and Forel* about the same time in Lake —__

Geneva. Their observations and explanations remained unnoticed

and in 1891 Richter* gave new and careful investigation to the _

subject and applied the term Sprungschicht to the stratum of

rapid change of temperature. His name for the stratum has been

generally adopted, as also his explanation of the phenomena, al-

though the latter is not wholly correct. Since this time the thermo-

cline has been observed by all the very numerous students of lake

temperature and much has been written regarding its nature and

origin.

It is worth our while to spend a few minutes in considering the

way in which the thermocline is formed, or rather, since the problem

is really a more general one, to consider the explanation of the shape —

of the peculiar curve which represents the vertical distribution o6 —__

temperature in a lake. (Plate II, fig. 2.) In all lakes of the

northern United States, with which alone we are concerned,

the temperature of the lake at freezing is but little above the

temperature of o° C. Ordinarily the bottom water, even in

a lake 30 m. to 50 m. deep has a temperature of not more than

1° to 2°, and in lakes whose depth is 20 m., or more, it may

easily be lower than 1°. During the winter the water under

the ice is warmed, mainly by the action of the sun, and at the

time of the melting of the ice in the spring the water has reached a

temperature of 2° to 4° C., and usually is nearer the higher figure. _

When the ice has disappeared the water of the lake is freely exposed _

to the action of the weather. Practically all of the heat received

by the water comes directly from the sun. Small amounts may be

absorbed from the air and by reflection from the shores of the lake, __

but these are so insignificant in amount that they require no special __

consideration. The rays of the sun as they fall upon the lake are, _

in part, reflected; in part, used in evaporating the water of the sur-

face; in very small part, employed for chemical operations in the

plants and animals of the open water; and the remainder of the

P-

*J. Y. Buchanan. On the distribution of temperature in Loch Lomond during — a

the autumn of 1885. Proc. Royal Soc. Edin., Vol. XIII, 1886, pp. 403-428. van

*F. A. Forel. Le Léman. Vol. II, p. 362, footnote. E-

*E. Richter. Die Temperaturverhiltnisse der Alpenseen. Verhandl. d. neun- < .

ten Geographentages zu Wein, 1891, pp. 176-189. ee

THE THERMOCLINE AND ITS SIGNIFICANCE 9

sun’s energy, passing into the water, is there converted into heat.

far the greater portion of this energy is absorbed by the stratum

of water immediately at the surface. Nearly one-half of the sun’s

‘energy is in the form of waves too long to be visible as light, and

‘these are absorbed by the first centimeters of water through which

they pass. Probably 30%, or more, of the energy present as light

is absorbed by the first meter, so that even in distilled water not

‘more than 30% to 35% of the energy which enters the surface of the

‘water is transmitted to the second meter. In natural water, which

‘is always rendered more or less turbid by the presence of suspended

inorganic matter and of algae and plankton animals, the absorption

much greater, and in lakes whose water, when filtered, is clear

and which are not at all exceptional in the amount of plankton which

they may contain, only 3% or 49% of the sun’s energy may be trans-

mitted to the second meter; 95%, or more, being reflected or

‘absorbed by the surface meter. If, therefore, the surface of the

lake were not disturbed by the wind, the lower strata of water would

‘be warmed during the course of the year very little, if at all. The

surface strata would be greatly heated during the day; they would

cool at night, to be again warmed as day returned, but the entire

play of summer temperatures in the lake would take place in a

shallow layer near the surface and the water at a very moderate depth

would be slightly or not at all warmed above 4° C.

_ But the lake is exposed not only to the action of the sun, but to

‘that of the wind, and the wind is the chief agent for the distribution

through the body of water in the lake of the heat derived from the

‘sun. This heat is distributed, in part, by the waves as they move,

_and especially as they break in whitecaps on the surface, but much

‘more effectively by the currents which the wind causes on the sur-

face of the lake.

Imagine a lake receiving no heat from the sun but exposed to the

action of a wind which is blowing steadily in one direction. The

surface water will not only be lifted into waves but will be driven

___ by the wind across the lake. As it reaches the leeward side, it must

_ feturn in some way, either around the edges of the lake, or across

the bottom, and, since almost all lakes are very shallow in propor-

. agatha hay such as is described, would finally set

_ the entire mass of the water of the lake into a sort of rotation, com-

| Pletely mixing the surface and deeper water. Such a mixture as

Io E. A. BIRGE

this actually occurs in late fall, after the lake has become homother-

mous. This is shown by the fact that even in lakes more than 70 m.

in depth the temperature of the bottom water before the lake freezes

falls below 4°, or the temperature of maximum density, and, fur-

ther, during this period of cooling below 4° the difference of tem-

perature between the surface and bottom water rarely exceeds 0.2

or 0.3° C.

If, however, the lake is exposed to the action of both sun and wind

the influence of the wind becomes modified. The surface water,

warmed by the sun, is driven across the lake but since the water

becomes lighter as its temperature rises, there is produced a thermal By

resistance to the mixture of the water and the rotation described

can not be set up unless the wind is very powerful. Instead of ming-

ling with the lower water and returning easily by deep currents, the

warmed water tends to remain on or near the surface and to accumu-

late on the leeward side of the lake. There is thus produced a sort

of wedge-shaped layer of warm water, thickest on the leeward side

and gradually tapering until it becomes very thin on the windward

side. This wedge-shaped mass is, of course, in a condition of un-

stable equilibrium because of its shape and density. Equilibrium :

may be restored in various ways. The warmed water may, in small

part, mingle with the cooler water by means of lateral diffusion cur-

rents. At night, as the temperature of the warmed surface falls, the

thermal resistance to mixture declines and the task of the wind is

rendered easier. On the cessation, or reversal, of the wind, the

warmed water may flow back toward the leeward side, thus pro-

ducing a surface layer of uniform thickness. If the wind is strong

enough or if the action of the sun and wind continue long enough, __

the warmed water may flow back to the windward side along the

shore, or beneath the surface and on top of the cooler water, thus

producing a warmed surface layer of nearly uniform thickness. It

is obvious that by one or all of these ways there could be produced __

on the surface of the cooler water of the lake a layer of warm water

with a transition layer immediately below it—the thermocline. a

If this were the entire story, the thermocline would be formed

permanently very early in the spring and the bottom water would —

be only slightly warmed above 4°. But, as a matter of fact, whilea

warm surface layer is frequently produced during the day in spring,

many days are so cool and cloudy that the small amount of heat

mixture that the winds may easily mix the

of that which lies below it. Almost always,

_ too, during the spring there occur periods of cold weather and high

during which the entire stratum of warmed surface water

will be cooled and mingled with the mass of the water of the lake.

_ By these means the entire mass of the water of the lake may

_ become warmed during the spring and the bottom temperature raised

_ considerably above 4°. In Lake Mendota, whose area is 39 sq. km.

(sepa gerne aun mesh Aerie or 12° ata

mutual relation of two

as it is warmed. The influence

the wind is proportional to its velocity and duration. The

| thermal resistance is greater when the sun is shining; it is diminished

_ at night, as the surface cools, and by cloudy or cold weather. The

_ depth and extent to which the distribution of the warmth will take

_ place depend on what may be called the algebraic sum of these two

—". The nocturnal cooling of the surface, and cooling due to

As the spring advances, the sun gets higher in the heavens, the

days become longer and warmer, the nights shorter, and the influence

of the sun upon the surface becomes greater. Under these circum-

stances there will come a time for each lake when even the strongest

winds are unable completely to overcome the thermal resistance

and when the action of the most violent and steady wind is able only

to mingle the surface water with a small portion of that which lies

below. Under these circumstances, a stratum will be formed on the

surface nearly uniform in temperature and whose thickness will

; _ depend on the depth to which, under the prevailing temperature con-

12 E. A, BIRGE

ditions, the ordinary winds are able to affect the water of the lake,

especially at night, when the thermal resistance is least. Then the

permanent thermocline will be formed and in the stratum above the

thermocline the diurnal play of temperature will go on.

The result of this action is to divide the water of the lake into

two main regions, with a transition zone between them. These are:

first, a surface layer in which take place the diurnal changes of

temperature—a stratum whose temperature is high and fairly uni- —

form, though ordinarily declining somewhat below the surface;

second, a transition stratum—the thermocline—in which the tem-

perature falls rapidly to that of the cooler water of the lower part of

the lake; and, third, below the thermocline and separated from it

by no distinct line, lies the mass of the cooler water of the lake. —

These thermal regions of the lake are very different in thickness

in different lakes. In large and shallow lakes, indeed, there may be

only one region, corresponding to the upper of the three regions

named. In Wisconsin, for example, there is Lake Winnebago—a

sheet of water more than 33 km. (20 mi.) in length, and perhaps 20

km. (12 mi.) in greatest width, with a maximum depth of 8 m. to

10m. This body of water is so large and so shallow that the wind

easily stirs it up to the bottom and the warmed surface strata are

rapidly mingled with the entire mass of the water. As a result, the

temperature of Lake Winnebago is odinarily uniform from top to

bottom in the morning, although at night the surface strata will usu-

ally be warmer, unless the day has been very windy. In lakes which

are in the same geographical region and whose depth in relation to

area is of a more common type, the thickness of the warmed surface

layer will vary with the area of the lake. In July the stratum may

be as little as 2 m. or 3 m. in thickness in lakes whose area is from

8 to 10 hec. (20 to 30 acres). In lakes whose area is 3 or 4 sq.

km. (one or more sq. mi.) the stratum may be from 5 m.

to 7 m. in thickness. In lakes whose area is from 15 to 30

sq. km. the warmed stratum may be from 9 m. to 12 m. hei

thick. In any case, it is true that the larger the lake the

thicker the warm layer, or, in other words, the deeper lies the — pe

thermocline. This fact is a necessary result of the formation of the

layer by the action of the wind, since in the larger body of water

the wind has a greater opportunity to act upon the surface. It ought

also to be said that the effective area of the lake should be con- es

THE THERMOCLINE AND ITS SIGNIFICANCE 13

. sidered, and the figures which I have given relate to lakes of fairly

___ simple outline. A very irregular body of water, mainly consisting

_ be much less influenced by the wind than a lake of simple outline.

__ A similar statement might be made for a lake a large share of

_ whose area is occupied by islands.

In different lakes the thermocline appears as a permanent feature

to appear before the middle of June, and in Lake Mendota it can

“a _ hardly be said to have a well-defined and permanent existence much

_ before July. It should be noted, however, that it frequently appears

_ temporarily at an earlier date and that the thermocline, in general,

_ is by no means a phenomenon of late summer and autumn, as some

_ of the earlier observers supposed. Other things being equal, the

time of its appearance is conditioned upon the area of the lake—

the date being earlier in the smaller body of water.

After the formation of the thermocline, the direct gains of heat are

confined to the stratum of water above it. By this means the lower

water is preserved in a cooler condition than would otherwise be the

a case. If the lake received its heat in smaller doses, as it were, such

water at the bottom had reached 6.5° by April 25; it was 7°

ma on May 6; and after that date no perceptible rise was made until

October. After the 1st of May the heat came so rapidly that the

_ += tuch cooler than in a lake of larger area and equal depth. In

_ Small lakelets the sun produces little effect directly, even at depths

___ which are very moderate. In one case the temperature at a depth

__ of 11 m. rose only about 0.2° C. (4.33° to 4.55") in 40 days, July 27

to September 5. A meter deeper no perceptible rise took place.

14 E. A. BIRGE

(Plate Il, fig. 2.) The sun’s effect is similarly confined to a small

depth in the larger lakes, but the influence of the wind is so much

greater as to prevent any direct proof of the fact by ordinary temper-

ature observations. Thus a very low summer temperature may be

maintained in comparatively shallow water if the area of the lake is

small, and if it receives little or no ground water. It is obvious

also that a cool spring, with its necessary alternations of warmth

and cold, leads to the distribution of more heat to the lower water

than does a warm season. Thus in Winona Lake in 1901 the bottom

temperature was about 8°, while at the present time it is 2.5°

higher.

It should also be added that the only periods when the entire mass

of water in a lake is circulated freely are during late fall, after the

lake has become homothermous, and the very brief period in the

spring before the water reaches the temperature of 4° C. Thermal

resistance prevents free circulation in the spring, and its effective

opposition begins at a very early date.

By the first, or middle, of July, at latest, a warmed stratum has

been formed on the surface of the lakes in this region of the United

States and the thermocline is to be found at a depth which varies

with the area of the lake but which is, in the same lake, about the

same in successive years. For some weeks very little change occurs

in the depth at which the thermocline lies. The surface of the lake

is still gaining from the sun more heat than it radiates to the air, and

the thermal resistance is such that it takes a very violent wind to mix

the water to a depth greater than that at which the thermocline lies.

Indeed, as one studies the temperature of the lake, he is surprised

at the force of this thermal resistance. Squalls of very considerable

violence and the strong winds which accompany summer showers,

and which may last for many hours, may temporarily depress the

thermocline on one side of a large lake perhaps 2 m. or 3 m., but they

have very little effect in permanently lowering the thermocline, which

rises almost to its former position when the wind ceases. One who

follows the temperature of a lake with daily observations and notes

the great oscillations of the upper surface of the thermocline and

its very slow sinking in early and midsummer comes almost to feel

that the upper surface of the thermocline offers such a resistance

to the mixture of water as a thin elastic layer of rubber might do in

the same position. In Okauchee Lake, for example, in 1898 the

‘

rs ee ee,

ee.

“«* %

PN Sr

* 3

THE THERMOCLINE AND ITS SIGNIFICANCE 15

upper surface of the thermocline lay at 7 m. below the surface on

_ June 28. Two and a half months later the upper surface was still

4 at the same level, and the temperature of the upper stratum of water

i tas not very different from that at the carlier date. In other lakes

_ the same conditions are found. In Lake Mendota the upper surface

__ of the thermocline at the middle of June, 1898, lay between 6 m. and

"__ 7 m. below the surface. Early in July it reached 8 m. and sank

____ little more than a meter during July and August. In other years, as

might be expected, the sinking is somewhat more rapid, but is always

very slow during July and early August. In Garvin Lake, in the

_ Same year, the upper surface of the thermocline lay at 4 m. on June

a8, and did not sink below that level in more than two months.

_ With the passing of the summer, as the nights increase in length

_ and the gains from the sun become smaller, the thermal resistance to

te Anpuet wad early Seguntber, hare to tron which often

ae ‘upper ’

____ surface water falls, the thickness of the warmed layer increases, or,

in other words, the position of the thermocline moves downward

during the late summer and the early fall. As this process goes on,

the thermocline is apt to sink with increasing rapidity, since the ther-

mal difference between the upper and the lower water becomes

smaller as the upper stratum cools, and the task of the wind, there-

_ fore, becomes easier. Usually the complete mingling of the water

of the lakes comes in connection with a storm. In Lake Mendota,

for instance, where most of my studies have been carried on, we have

a lake about 10 km. (6 mi.) in length by 6.5 km. (4 mi.) in width,

and with a maximum depth slightly exceeding 24 meters. The ther-

_ mocline gets very near the bottom by the latter part of September, at

_ which time the surface temperature may be about 18° and that of the

bottom about 15°. Frequently the complete mixture of the water

takes place during the gales which are wont to occur at the close of

that month, or in early October. Should these not come, however,

the equalizing of the temperature may not be brought about until late

in October or in November. In smaller or deeper lakes the process of

equalization lasts until later, and undoubtedly in the deepest lakes

the homothermous condition is brought about more by the cooling

16 E. A. BIRGE

of the surface water than by the overturning of the mass of water

in the lake by the action of the wind.

This, then, is a brief sketch of the thermal history of any of our

northern lakes. Starting in the spring, at a condition of thermal

homogeneity, there is developed a condition by which the lake

becomes separated into two very distinct thermal regions—a shallow,

warm, surface layer resting on and ordinarily considerably thinner

than the cooler bottom portion of the lake. These are connected by

a transition stratum, the thermocline. During late summer and fall

the warm layer loses heat and also gains in thickness by mixture

with the subjacent water, until finally at some time during the

autumn thermal homogeneity is reestablished.

These thermal changes must have a considerable effect on the

physical conditions of life in a lake. The change of temperature

at the thermocline is itself a factor which may influence directly the

vertical distribution of life in a lake. Still further, change of tem-

perature is accompanied with other physical changes. The cooler

water is denser, and, therefore, plankton plants and animals may

float in this denser water, which would sink in the warmer water

above. Ostwald* has very recently pointed out that the viscosity of

water increases as its temperature declines, and increases at a much

more rapid rate than does its density. This increase of viscosity

must affect the rate of sinking of plankton animals and plants, and

so their vertical distribution. As yet, however, no

work in this direction has been published. Undoubtedly this newly

suggested factor is a real one and its influence must be studied and

evaluated. The initial influence of the viscosity of water is still

unknown and it is, therefore, difficult to see how great the value of

its increase will be. It appears also that it will not be easy to dis-

tinguish between the effects due to increased density and those due

to increased viscosity.

Besides these more direct effects of the change in temperature at

the thermocline, there are others less direct, but even more im-

portant in their influence on distribution. After the thermocline has

been established, the water below is cut off from any direct access

to the air. It is also deprived in great measure, though not entirely,

of the effects which come from circulation induced by the wind.

*W. Ostwald. Theoretische Planktonstudien. . Zool. Jahrbiicher, Abt. far Sys-

tematik, Vol. XVIII, 1903, pp. 1-62.

THE THERMOCLINE AND ITS SIGNIFICANCE 17

_ The movements of the warmed stratum occasion slow movements

in the lower water, but these are very small and feeble as compared

with the vigorous movements in the upper stratum. It is obvious

also that the gaseous contents of the lower water are likely to become

_ quite different from those of the upper stratum. All of the leaves

blown into the lake, all organic debris washed into it, all of the

_____ Plankton plants and animals, as they die, sink into the lower water

Rt and are there decomposed. Oxygen is consumed in this process and

may almost entirely disappear from the lower water, as it is supplied

_ only slowly to this water by diffusion from the upper stratum. The

_-—s gases formed by decomposition escape also slowly, partly because

___ Of the lack of circulation, and partly because of the distance through

_ which diffusion has to take place. The extent of this influence on

__ @ases and the substances dissolved in the lower water will depend

_--—~— om the amount of plankton or other organic matter present in the

. fake, on the volume of the water in the lower stratum, and on the

) temperature of the bottom water, which regulates the rate of decom-

position. In large and deep lakes little, or no, influence of this

kind can be detected. In small ponds, where the organic content is

great and the bottom temperature high, the lower water may become

very foul, ill-smelling, and discolored by the products of decomposi-

tion. All possible gradations between these extremes may be ob-

served.

Another result of this thermal stratification of the lake is to pro-

duce like temperature conditions in the upper water of lakes in the

_ Same region, and so to render uniform the conditions of life near the

surface. Very numerous observations have shown that lakes differ-

ing very greatly in area and depth and distant perhaps 100 miles

from each other, differ no more in the temperature of their upper

water than does the same lake at different times of the day. It

| ___ might be thought that the warmed layer of the smaller lakes, being

| __ Shallower, would be much more highly heated by the sun than is

| __ the thicker stratum of the larger lake. Yet this is not the case. The

diurnal changes are somewhat greater in the smaller lake; and at

noon of a hot day, with a slight breeze, the temperature of the sur-

face in very small lakelets is higher than in the larger body of water.

Yet a lake whose area is a sq. km. or even less has a surface tem-

perature essentially the same, for biological purposes, as one of 50

times that area. There is then a general uniformity of temperature

oo ae il ea a acl aa

— ¥

— '

18 E. A. BIRGE

conditions at the surface. Different lakes in the same region differ

far more widely in the thickness of the stratum above the thermo-

cline than they do in its temperature, and for biological purposes,

this stratum may be regarded as essentially identical. The tempera-

ture of the subthermocline in different lakes differs much more

widely, as also does that of the water at the bottom.

During the summer, then, our typical northern lakes really consist

of two lakes, one superposed on the other: first, the lake above the

thermocline, whose temperature is high and whose water is kept in

active movement by the wind; and below this, the stagnant mass of

water below the thermocline, having a low temperature, denser and

more viscous than the upper water, in which the gaseous and other

products of decomposition are accumulating and from which they

are only slowly and partially discharged.

Let us now turn from this general consideration of the physical con-

ditions produced in the lake by the summer temperatures, and ask

what effect this stratification of the water has upon the plants

and animals of the plankton. We must say frankly at the outset that

comparatively little is known in detail regarding this subject. As

soon as investigation begins, it appears that we have not before us

a simple problem which can be promptly solved, but that the question

of the relation of the thermocline to life is one factor in the ex-

tremely complex subject of the vertical distribution of animal and

vegetable plankton. What I have to say, therefore, will be much

more in the way of suggestion than of presenting final results.

The following account of the biological influence of the thermocline

on the vertical distribution of the plankton is based upon observa-

tions made upon lakes in Wisconsin. By far the most numerous and

continuous observations were made upon Lake Mendota, which is

immediately adjacent to the grounds of the University of Wisconsin.

During the summer of 1898 observations were made about once in

two weeks upon five smaller lakes in the Oconomowoc district, some

40 miles from Madison, and observations fewer in number, not ex-

ceeding two or three in a season, were made on more than 30 other

lakes, chiefly in southern and central Wisconsin. The material from ~

Lake Mendota comprises several hundred sets of observations. There

are something more than 100 sets of observations from the other

lakes. These, while sufficient to give a general idea of the vertical

distribution of the animals and plants referred to, are not sufficient,

THE THERMOCLINE AND ITS SIGNIFICANCE 19

—e _ except in Lake Mendota, to allow accurate conclusions to be drawn

a the several species. My studies on Lake Mendota make

. SI as tn coder to, dlasese. the: doccielen snd dstribation of

_ forms in any lake with sufficient accuracy, it is necessary to follow

_ them through at least one season with observations made as often as

_ two or three times a week. This task, however, involves so great

"af amount of work that it is practically impossible to perform it for

eee coe oF two lakes. The student must choose between

‘a * general view of many facts and an accurate knowledge

— a

‘The relation of the thermocline to the vegetable plankton may

ae be briefly stated. In general, the thermocline produces little direct

_ effect upon vegetable life. The algae of the lake are so dependent

upon sunlight that the greater part of the active vegetation is con-

tained in the upper water which lies above the thermocline. Un-

_ doubtedly, the surface meter contains far more than its proportion

of these algae. In lakes of considerable size, where the thermocline

is 10 m., or more, below the surface, there would naturally be

very little active plant development at its level. In the lakelets

of small size, where the thermocline lies only 3 m. to 5 m. from the

_ surface, the thinness of the stratum of warm water may exert an

influence on the amount of algae in the lake and so on the amount

___ Of animal life which it can support. In lakes which are not pecu-

__ liarly transparent green plants may grow from the bottom at a

depth of 6 m., or more, and in lakes whose transparency is such that

Secchi’s disk can be seen to a depth of 5 m. to 6 m., there should be

light enough to permit the active growth of algae at a depth of at

least twice that distance. When, therefore, the temperature of the

water at 6 m. or 7 m. is as low as 12° or 15°, there must be exerted

an unfavorable influence on the total amount of vegetable life which

the lake will support. So far as I know, however, no studies of

this influence have been made, and it would probably be very difficult

to distinguish this among the other, and mainly unknown, forces

which make the difference between a lake rich in plankton and one

containing little.

_ In another way, however, the thermocline has a very interesting

relation to the algae. The fact is well known that in any lake the

forms of algae appear in succession and each occupies the upper

water almost to the exclusion of other species, then gradually passes

20 E. A. BIRGE

away and its place is taken by another form. As any species of alga

declines in number and dies out, it sinks gradually and it is found

that under these circumstances the dying algae frequently accumulate

in great numbers at the thermocline, so that at certain periods, lasting

for as much as two days, the stratum included in the thermocline

may contain a larger share of the alga-life of the lake than any

other stratum of equal thickness. So far as my experience goes,

this pausing of the sinking plants at the thermocline is more marked

with the diatoms, such as ‘ Fragilaria, Melosira, and Diatoma, than

with the blue-green algae. Botanists now tell us that the structures

which keep these diatoms in suspension in the water are not cer-

tainly known. However this may be, it is clear that they are main-

tained in suspension by vital and not by mechanical means.

have none of the long spines which constitute the Schwebeverricht-

ungen of such genera as Rhizosolenia or Atheya. Those who have

collected Fragilaria know that it very promptly settles to the bottom

of a vessel when taken out from the lake, although it will remain for

days, or even for weeks, suspended in the open water.

A moment’s thought will show that the halting of these sinking

algae at the thermocline is not a physical phenomenon, due to the

decline of temperature and the increasing density of the water. If

this were the case, the halting would only last long enough for the

diatoms to acquire the temperature of the water, and, while their

downward progress would be delayed, the halting would not extend

beyond a very few minutes, although the sinking in the cooler water

might be slower. Probably the cool water checks the progress of

senescence and prolongs for a time the decaying life of the alga.

These diatoms are among the favorite food of the crustacea and

indeed are preferred by most of the crustacea to the blue-green algae.

At such times, therefore, as the successive crops of diatoms are

found in the region of the thermocline, they are frequently accom-

panied by large numbers of crustacea, which then find more abund-

ant, or more appetizing, food in that region than nearer the surface

of the lake.

Under the conditions of plant life which have been thus described ~

the number of algae found in the water of the subthermocline is

ordinarily very small. This fact is not due to the distance from the

surface and the consequent diminution of light, for the water close

to the thermocline in Lake Mendota always has an abundant popu-

THE THERMOCLINE AND ITS SIGNIFICANCE ar

lation of algae, which follows the thermocline downward as it de-

seends and which in the autumn occupies the whole of the water, to

the depth of 25 m., after it has become homothermous. In summer

the algae, as they sink, seem to delay at the thermocline until they

are dead, or so nearly dead that they fall rapidly to the bottom after

passing that level. The crustacea which follow them to the thermo-

cline do not go further with them; thus showing that other causes

than lack of food prevent the occupation of the subthermocline by

animals. Occasionally, therefore, large quantities of algae may be

obtained from the lower water, with almost no crustacea or rotifers.

Such periods are short and infrequent and usually the net brings up

very little of either animal or vegetable life from this region.

_ In lakes whose lower water is habitable, the great masses of algae

common in Lake Mendota are not often found. Yet the algae of

_ such lakes also halt at the thermocline as they sink, and thus give

_ Occasion to accumulations of food at this point, and are probably one

: eS Cre roe of Stettete set letreety found

In still another way, the thermocline may have an important in-

‘eg direct effect on vegetable life. Whipple’ has pointed out that the

____ products of decomposition, all of which accumulate in the subthermo-

__ ¢line, constitute a sort of nutritive medium for the growth of algae,

_ which can not be utilized because of the absence of sufficient light

and warmth. As the thermocline moves downward, this nutritive

material is distributed to the upper water, where it becomes available

__ for plant food. He says also that when the thermocline disappears

in the autumn and the water of the lake is “overturned” a large and

| sudden addition of plant food may be made, which will cause a great

__ development of algae. He correlates with this overturning the

___ appearance of large crops of algae in the autumn. This relation un-

~ doubtedly exists in the bodies of water which he observed, but in

_ mone of the lakes which I have studied is the accumulation of the

i" re any chourvabte cflects.

___ In addition to these relations of the thermocline to vegetation, the

22 E. A. BIRGE

change of temperature at this level must also produce other effects.

The increase in density of the water as its temperature declines must

have an influence on the sinking of those algae whose specific gravity

is only slightly greater than that of the warmer water in which they

live. This is especially true of the blue-green algae, whose density

during life hardly, if at all, exceeds that of the water. As these die

and gradually sink, they must tend to linger at the thermocline, in

consequence of the increased density of the water. The same effect

must be produced by the increased viscosity of the water due to

decreased temperature. Neither of these changes, however, appears to

have any considerable influence on the rate of sinking of the ordi-

nary plankton diatoms, whose specific gravity is considerably greater

than that of water. Experiments show that they will pass in a very

brief space of time an artificial thermocline considerably sharper

than that in any lake. A greater effect may be produced on plants

too small to be seen by the unassisted eye and these changes in

density and viscosity may determine their position.

The relation of the thermocline to the vertical distribution of ani-

mal life is a far more complex matter than its relation to the algae.

The change of temperature at this point may affect animals directly

or indirectly. In the first case, the decline of temperature itself limits

the downward movement of the plankton animals, or the rapid in-

crease in warmth forms a barrier to their migration into the upper

strata of the lake. Indirectly the change of temperature modifies the

action of other forces, such as light, which are effective in determin-

ing the relation of the plankton animals to the surface. The stagna-

tion of the lower water, which results from the thermocline, with

the attending chemical changes, may also indirectly limit distribu-

tion. The increase in density and viscosity of the water, which

accompanies the decline in temperature, will also exert an influence

on the rate at which the plankton animals sink, and it may be found

that these alterations are sufficient to permit animals to float at this

level, which would sink in the warmer water above. This possibility

holds especially for nauplii and other young forms. The adult crus-

tacea and the rotifers which are large enough to be seen by the

naked eye sink quite rapidly, both in the water above the thermocline

and in the cooler water below.

It is not easy to trace any direct influence on vertical distribution of

the change of temperature. at the thermocline. Other factors than

THE THERMOCLINE AND ITS SIGNIFICANCE 23

t temperature are so much more important that the influence exerted

by this one can hardly be detected and in few cases does it appear

probable that temperature determines the position of animals. The

__ best example of an animal whose position seems to be determined by

the temperature of the water is furnished by the well known mem-

ber of the Cladocera, Diaphanosoma, or Daphnella. This genus ex-

‘ists in two closely allied species ; one inhabiting weedy water and

‘marshes where the water is, of course, very warm; the other is

limnetic in its habits. The latter species is more narrowly limited

by temperature in its seasonal distribution than any other important

member of the plankton crustacea. It appears later in the season

and disappears earlier than any other form and while it is present,

it is always confined to the region above the thermocline. Occa-

‘sionally a few specimens may be captured from below the thermo-

cline, but a large majority of such straggling individuals are dis-

eased or have been unable to complete the shedding of the skin, or

are in some way obviously disabled. Within the warm water above

_ the thermocline the distribution of these animals is determined by

various factors, which need not be discussed. The species differs so

_ widely from other genera of plankton crustacea in never seeking the

_ cooler water below the thermocline that it is not unfair to conclude

‘that temperature is the most important factor in confining it to the

; ce. It must be granted that light may also have its

influence, but, as Diaphanosoma reacts negatively to a very bright

light, and as the species occupies the whole of the warm water,

___ whether 4 m. or 12 m. in thickness, the lower limit of its distribution

____ Seems to be set primarily by temperature.

_ There are two other forms of crustacea which it is possible may

also be confined to the superthermocline for the same reason. There

re Ceriodaphnia lacustris and the copepod Epischura, The former

_ erustacean has been found only in the superthermocline but has ap-

peared in small numbers and in few lakes, so that I hesitate to make

ly general proposition regarding it. Epischura was found only in

le superthermocline of Green Lake by Marsh. I have never found

in sufficient numbers in other lakes to warrant any definite state-

ment regarding its distribution. In Lake Mendota, where it has

‘sometimes appeared in considerable numbers, it has ordinarily been

found in the deeper water during the day, but this has been in the

_ fall when the thermocline had moved far down. In Winona Lake it

24 E. A. BIRGE

has been found to live in the thermocline by day and to move upward

at night.

There is no rotifer which has been shown to be excluded from

the thermocline by temperature. I am somewhat disposed to think

that Conochilus may be such a form, but as I have found it in large

numbers in Lake Mendota only, I can make no positive assertion, for

reasons which follow.

The stagnation of the water below the thermocline, with the —

accompanying changes in its gaseous contents and dissolved matters,

may become a very important factor in excluding the plankton ani-

mals from this region. Lake Mendota is an example of a lake

whose subthermocline is almost uninhabitable. In that lake the en-

tire mass of the water of the lake is freely occupied by crustacea and

rotifers during April and May, and also late in the autumn. As

the thermocline begins to be formed and the lower water becomes

stagnant, the animals are gradually driven out of it, and after the

early part of July the subthermocline is practically devoid of plankton

animals. The few crustacea and rotifers which are found there are

evidently diseased or feeble and are gradually sinking to the bot-

tom. The suddenness with which the animal life disappears at the

thermocline is very remarkable. I give a diagram (Plate II, fig. 1)

showing the condition of the vertical distribution on September 8,

1896. At that date the thermocline began at 13 m.; at 12 m. nauplii

were found at the rate of more than 220,000 per cubic meter; at 12.5

m. the number had fallen to 108,000; at 13 m., to 22,000; and at

13.5 m. and below, none were found. The adult crustacea ended

with almost equal suddenness, though the absolute numbers were not ©

nearly so great—something more than 10,000 per cu. m. being found

at a depth of 12.5 m.; 2,000 at 13 m.; 400 at 13.5 m.; below which

only an occasional straggler was found. Thus within the limits of a

meter to a meter and a half at the thermocline the plankton popula-

tion suddenly ceased.

It should be understood that this sharp limitation of the vertical

distribution of the plankton animals is not due to the change of

temperature at the thermocline. This fact is shown plainly by the

relations in other lakes in which the vegetable plankton is less abun-

dant, or the bottom water greater in quantity and colder, and in

which the animals are freely distributed to all depths. It is the rule

in the smaller lakes of Wisconsin that the animals occupy the whole

THE THERMOCLINE AND ITS SIGNIFICANCE 25

SNE ths weatisebttUaly ie thiee or Sour of the Inks has a relation

a eee All of these lakes have

ibundant plankton and a comparatively small amount of water be- -

Ra the thermocline. They are of all sizes, however, the smallest

being only 8 hectares (20 acres) in extent, and the largest 39 sq. km.

(15 sq. mi.).

_ The subthermocline in these lakes is not entirely devoid of animal

life. In Lake Mendota the mud is inhabited by Cyclas, and also by

1 few worms. These animals have not been found in the other

lakes, where the conditions of bottom life are perhaps not as favor-

able as in Lake Mendota. The water of the subthermocline is in-

i ecalhe dad talibea uitet teksigioan. and most beautiful

———_torhaahrden poten It is one of the animals

i. has no difficulty in remaining there for a considerable ups of

_ time. So far as my observation goes, it is most numerous in those

ie 07 Se cratnce absolute number of Corethra larvae caught

_ from the subthermocline exceeds that of the crustacea and rotifers

is hardly anything in the water surrounding them on which they

can feed. It is probable that the action of light determines the posi-

tion of these larvae, yet, although it is easy to understand the possi-

4 bility of their passing the day in the water of the subthermocline, it

is difficult to see why their habits should not have become adjusted

to acontinuous existence in the warmer water which they do not find

_ wncomfortable at night, and in which their food is so much more

ease! then in the deeper water.

In lakes of the type of Lake Mendota only the upper water is occu-

_ pied by plankton animals during the summer. In other words, of the

. P two lakes into which the body of water is divided, only one is habit-

26 E. A. BIRGE

able. This fact exerts a considerable influence on the total quantity

of animal life supported by the lake during the summer, as the num-

ber of animals is limited by the shallowness of the stratum to which

they are confined. In each of the years during which the crustacea

of Lake Mendota were studied, a midsummer minimum was found

in the number of these animals. This was probably caused, in part,

by the high temperature of the water, and, in part, by the exclusion

of crustacea from the thermocline. Still further, the autumnal in-

crease in the number of crustacea in this lake comes almost wholly

from the progressive occupation of the lower water. As the ther- —

mocline moves downward, the population of the upper strata in-

creases only very slightly, or, if any considerable temporary increase

is found, it is due to the appearance of swarms of young, which live

near the surface at their first appearance. The lower water, how-

ever, contains in the fall an abundance of algae in a healthy condi-

tion and supports a large population of plankton animals until the

decrease of temperature in November causes a decline to their winter

numbers,

We now turn from these lakes whose subthermocline is not habit-

able by the plankton animals, to those in which the lower water is

abundantly supplied with oxygen and is, therefore, capable of sup-

porting animal life. The first question which arises is the reverse of

that which we have answered for the superthermocline; namely: are

there animals which are confined to the subthermocline during sum-

mer because they are unable to endure the high temperature of the

upper water? This is very probably the case with some of the crus-

tacea found only in very deep lakes. In Green Lake, Wisconsin,

which is more than 70 m, deep, there is an abyssal fauna, closely

corresponding with the deep water fauna of Lake Michigan, It

contains Mysis and Pontoporeia, the latter one of the amphipods.

Whatever may be the cause which first drove these crustacea into the

deeper water, it is certain that they always remain here, and, so far as

is known, do not appear in the warmed surface water, either by day

or by night. Besides these representatives of the higher crustacea,

there is also found in the depth of the lake the copepod Limno--

calanus, which, Marsh reports, is confined to the deep water during

summer. The animal, however, has appeared in surface collections

made by night in Lake Geneva, so that it is not absolutely confined

to the subthermocline.

THE THERMOCLINE AND ITS SIGNIFICANCE 27

IE cesichiek:46-ias, Cladeicars ‘tik biptaved caty: tx collections

_ from the bottom water of the lakes. This is Daphnia longiremis—

a form belonging to the hyaline section of this genus and distin-

guished, as the name implies, by extremely long antennae. This

species has been found in a few lakes only, whose waters are deep in

__ proportion to their area and consequently are cold. In these lakes it

was always found close to the bottom. It has never appeared in

within a few meters of the bottom and in largest numbers just above

the mud. Its position here is very possibly determined by the pres-

_ ence of food and there is no reason to suppose that temperature

alone determines its position. This species has never appeared at

the surface in collections made by night, yet the observations on this

subject have not been sufficiently numerous to warrant me in assert-

__ jing positively that it never comes to the surface. We are, however,

_ warranted in stating that, so far as is known, this is the only member

of the common genera of plankton crustacea which, by preference,

_ occupies a position at the bottom of the deeper lakes in the coldest

__ water to be found—water whose temperature ranges from 6° to 8° C.

The most interesting of the animals found, by preference, in the

_ subthermocline, is Daphnia pulicaria. This is a large, stout Daphnia,

| belonging to the pulex group. It is found in many lakes and during

the summer is regularly an inhabitant of the subthermocline. It

_ sponds negatively to light, and this fact appears to determine its

_ position in the lake, the lower temperature of the water of the

thermocline being effective in lessening or reversing the negative

action of the light. It is well known that many of the plankton ani-

mals respond negatively to light, moving downward in the water to

varying distances according to their sensitiveness to this influence.

This negative action of light is greatly increased as the water be-

comes higher in temperature and when the temperature of the water

is lowered the animals may become indifferent to light, or may move

____ toward a light which would repel them were the temperature higher.

__ Such seems to be the case with Daphnia pulicaria, It is found at the

surface in the spring and until the water reaches its summer tem-

perature. It also has a period of active reproduction late in the

autumn, when the water has cooled, and then occupies the water at

28 E. A. BIRGE

the surface, as well as at all depths. In winter it may often be seen

in great numbers immediately below the transparent ice. In summer,

however, it moves downward below the thermocline and is found

there alone, though occasionally a few straggling individuals may be

captured in the warm water.

That the position of Daphnia pulicaria is determined by light

rather than by temperature appears from the fact that in certain lakes

it comes to the surface at night, moving upward into water often as

much as 15° C. warmer than that which it occupies by day. This

upward movement is probably in search of food and the absence of

light is a condition and not a cause of the migration. The species

has been found to appear at the surface about two hours after sunset

and it disappears before sunrise, while the sky is still dark. If tem-

perature alone determined its position in the subthermocline, it would

not move upward into the warmer water at all.

While this species may be found throughout the subthermocline

of the lakes which it inhabits, the largest numbers are wont to stay

in the immediate neighborhood of the thermocline. This is probably

due to the fact that this stratum contains a larger amount of food,

for reasons which have already been stated, than does any other

equally thick stratum of the lake below the surface. Possibly the

action of the light becomes positive in the cooler water. Yet the

animals are so generally distributed in the subthermocline as to

render this hypothesis improbable. In Lake Mendota, whose sub-

thermocline is not habitable by the plankton crustacea, Daphnia puli-

caria is present and in summer is forced to occupy a very narrow

space just at the thermocline. Almost all of the members of the

species are ordinarily found in a stratum of water not much more

than a meter thick, at the junction of the thermocline with the

warmer water above; the temperature preventing it from rising into

the warmer water, and the nature of the subthermocline making it

impossible for the animal to descend into it. In this lake no vertical

migration of the species at night has been detected.

When now we turn to the other species of crustacea and rotifers

comprising the great mass of the plankton animals, we have to do .

with forms which are not confined to any one thermal region of

the lake, and we can speak only of a preference for this or that region.

We find also in different lakes and on different occasions in the same

lake a varying distribution of the same species. It is evident that

; are light and food, yet these affect different species in very different

‘degrees and the thermocline has a marked influence on the distribu-

tion of most forms.

The two genera of Copepoda which contribute most to the plankton

are Cyclops and Diaptomus. The former genus is more uniformly

distributed through the water than any other of the plankton animals.

It is comparatively indifferent to light, and temperature has no

__ noticeable influence upon it. Diaptomus responds much more defi-

____ mitely to light and a larger proportion of individuals is usually found

____ im the upper strata of water. In neither genus is any sharp break

____ im distribution regularly made by the thermocline. At times there

are found large aggregations of both of these genera at the thermo-

i _ cline. In some lakes Diaptomus seems to be driven by sunlight into

_ the thermocline by day, rising into the warm water at night. The

Sil iaind statements may be made for the nauplii as for the adults of both

these genera of Copepoda. In the illustration which I give of the

distribution in September, the majority of the nauplii were aggre-

_ gated just above the thermocline. I have never found these aggre-

_ gations, which may be very great, elsewhere than at the surface and

thermocline. In the case of the adult Copepoda, the swarms, as they

a become old, are wont to move downward in the lake and occasionally

large numbers of adults are found close to the bottom. This is evi-

dently the result-of old age. The aggregations at the surface and

thermocline are probably, although not certainly, due mainly to the

food which is present at these places, either in large quantities or in

i) Reems which are especially desired. The surface meter and the ther-

_ mocline are the two regions of the lake in which great crowds of

plankton animals may be found, and it rarely happens that some

species or other is not present in unusual numbers at the thermo-

cline.

The member of the group of Cladocera which is universally pres-

_ ent in the plankton is Daphnia hyalina. The distribution of this

____ Species corresponds very closely with that of Diaptomus. Like that

__—s genus, it is ordinarily most numerous in the upper water, but it is

also true that large aggregations of the species may be found at the

thermocline—a fact which again is probably attributable to food.

A large number of species of rotifers are, in like manner, dis-

30 E. A, BIRGE

tributed through the waters of the lakes; aggregated occasionally in

great numbers at the thermocline, at the surface, or at the bottom,

or again, more uniformly distributed through the entire depth of

the water. Many more observations would be needed on these ani-

mals, as well as on the crustacea, in order to work out in detail the

laws of their distribution. Yet so far as my observations extend,

certain preferences in position are indicated. Among the common

rotifers which are ordinarily, though not exclusively, found in the

warm surface water of the lakes in summer are Asplancha, Polyar-

thra, Conochilus, Mastigocerca,and Anuraea cochlearis. Those found

by preference in the cooler bottom water are Anuraea aculeata and

Notholca longispina, In all of these rotifers the distribution was, in

general, as indicated, yet not without exception. In several cases

swarms were found at the bottom, even of the deepest lakes. Yet

in these cases the animals were all adult and it appears probable that

these constituted the last part of a generation-cycle. In all cases,

too, there were found some exceptions to the general rule of dis-

tribution ; the rotifers which ordinarily belong below the thermocline

being above it in certain lakes, and vice versa. These exceptions,

however, were few in number. In no case does it appear probable

that the change in the temperature of the water constitutes in itself

an important barrier to the movements of these animals. Yet we are

also warranted in saying that the preference of one set of species

is for the warmer water and of the other is for the cold. This is

especially noticeable in the case of the closely allied species Anuraea

cochlearis and A. aculeata, These are found in the same lakes and

frequently in considerable numbers, although the former species is

ordinarily by far the more abundant. In no case where the two

species were found together was the arrangement other than

that which was indicated; A. cochlearis occupying the upper water,

although extending into the subthermocline; and the majority of

the individuals of A. aculeata coming from below the thermocline.

From this account we may fairly infer that the thermocline con-

stitutes a critical point in the distribution of the plankton in the

water below the surface. No single factor within the water itself

compares with it in importance. The direct influence of the change

‘of temperature is not very great and in this respect the difference of

temperature in the lake corresponds to temperature differences in

general. Most plants and animals of temperate regions are not par-

Se ee ye ee

THE THERMOCLINE AND ITS SIGNIFICANCE ry ae

_ ticularly sensitive to a change of a few degrees of temperature. For

_ some Species, however, the change from warm to cool water consti-

tutes the factor which determines their vertical distribution. Indi-

rectly, the effect of the thermocline is far greater. The stagnation

of the lower water, with its attendant chemical results, causes a sharp

_ limitation on the distribution of the animal life in many lakes. The

thermocline in these lakes marks the limit of the thriving of algae and

thus directly limits the distribution of plants and indirectly that of

the animals which feed upon them. In all lakes the thermocline has

an evident influence upon distribution, and, although it is by no

means an impassable barrier, most species of plankton animals live,

__ by preference, either above or below it. The fact that the thermo-

___ éline is the one stratum below the surface where large numbers of the

__ plankton animals are often aggregated is sufficient to indicate its

importance.

‘The thermocline is, however, only one factor in the complex of

_ forces which determine the position of plants and animals in the

_-—s' water of our lakes. Some of these, as light and food, density and

___ viscosity, have been named, but these, with temperature, are not the

_-—s gnily factors. Others, like gravitation, have an effect difficult to

trace, but none the less real. Competing species and plants of the

plankton which are not edible have an influence which the observer

can feel but whose value he finds it even more difficult to estimate.

Each of these forces is independent of the others, both in the direc-

tion and the intensity of its action. They differ in their effect on the

____ individuals of different species and their influence on the same animal

may change as it passes from youth to maturity and old age. Still

more, these forces are affecting animals of highly complex organiza-

tion, whose reactions are not always marked by the directness and

uniformity of a unicellular animal.

Thus the problem of the vertical distribution of plankton animals

becomes very complicated and requires for its full solution far more

mumerous and careful studies than those on which this address is

based. It was an investigator and a lake of Indiana that suggested

the phrase: “ The lake as a unit of environment.” The years which

have passed since that phrase was uttered have shown, on the one

hand, its essential truth, and, on the other, have partially revealed

to the student of lake biology the great inner complexity of this unit,

and the amount of research which its problems demand. This ques-

32 E. A. BIRGE

tion of vertical distribution on which I have touched is among the

simpler problems of the lake. Yet we have no accurate knowledge

of the effects of any one of the factors which determine it, nor do

we know how these factors influence any one species of the plankton.

Here is a wide field open to the investigator. I say “ open” because

any student may work in it. Complicated apparatus and difficult proc-

esses are not demanded; at any rate, for the present. Patient and

intelligent observation by day and night with pump, plankton net, and

microscope, will be rewarded by large additions to knowledge. By

these means we may hope to make a beginning in unraveling the

tangled story of the interrelations of the inhabitants of this “ unit of

environment.” We may hope thus to trace, in part, their relations

to the lake in which they live and to the forces of the larger world

which act on them with an apparent simplicity, all the more provok-

ing as it masks a real complexity so great that the increase in our

knowledge of the facts seems thus for to bring little more than

increase in ignorance of principles. Each lake and lakelet, almost

each species in each lake, seems thus far to be a peculiar case and

to have its own singularities so marked that it is difficult, or impos-

sible, to unite them in any general statement. Only a large body

of most careful observations can furnish material which will show in

what sense each lake is “a unit of invironment,” and how each fur-

nishes but a special case in the larger statement of the laws of lake

biology.

PLATE I

SEPT 2°° 1698

MAY 30°" 1898

GARVIN MENDOTA OKAUCHEE GARVIN MENDOTA OKAUCHEE

— 19.5, — 18) 244 — ,25° _

—- -_ — —— - 25-4 _

ea Nes 25 on inns

. -10- ; aoe

5 ss 5- 703 5- ead 5-

ee eB = a

ge. cee =

a es Ea

10- oe ae H+ -10-F— -I0

ae -10- - A

66| ~~ ra) 201

= _ | on —

Le} }— -+4

-15-

—— wes

mee SS

-20- -20. -20-

-B-| | ~-%-—

“

am 7S al

PLATE Il

<—

Fig. 1.

20°

io“

i5™

§°

1o*

Fig. 2.

ise

sEe8 233

one meter in

per

pump at the depths

crustacea present.

or nauplii

the

surface warming,

weather

depth o

They

11 m.

EXPLANATION OF PLATES

Plate I

scale indicates

0,000

, or 1°

by the

number of

between

slight

at the

Beasley Lake,

the amount

dates named.

depth of

the vertical

space

per

was

of the

number

curve

7 m. and 8

curves

These curves

days between

nauplii, and of temperature, in Lake Mendota September 8,

THE THERMOCLINE AND ITS SIGNIFICANCE

cid ieee a6 tiles Cullis Chniaben end: Misedets: ad Sey

and September 2, 1808. The depth is indicated by a scale placed beside

¢ columns on which is platted the distribution of temperature. For fur- |

explanation see text.

Plate II

__ Fig. 1. Curves showing the vertical distribution of adult crustacea of all

eee Oo -

A, a

ewes a

eee tes ae

oan THE FINER STRUCTURE OF THE HEART MUSCLE OF

THE DOG

By GERTRUDE A. GILLMORE

WITH THREE PLATES

During the winter of 1900-1901, the writer began the investiga-

____ tion of the finer structure of the heart muscle with a view to the

_____ @lucidation of the relation and meaning of the discs. At that time,

with the exception of the papers by MacCallum, little or no detailed

work on the finer structure appeared to have been done. One found

substantially the same brief descriptions and drawings repeated again

and again. From these descriptions little information could be

gained beyond that of the shape and anastomosing of the cells, the

position of the nuclei, presence of the cell cement, the existence of

striations, and the supposed absence of sarcolemma. Even the con-

tinuity of Krause’s membrane was not generally understood. There

seemed, therefore, a need of more detailed work on the finer struc-

ture of heart muscle.

The facts here given were substantially worked out during the

winter of 1901 while in the department of Histology and Embry-

ology of Cornell University, but were not published.* Now, that

Heidenhain has published such important results, it is hoped con-

firmation and comparison of some points will not be unwelcome.

After a year’s unavoidable delay, the writer, through the kindness

of Dr. Whitman, has been able to continue her work at the Marine

Biological Laboratory, Wood's Holl, Massachusetts.

The heart assigned for study was that of a dog, with comparative

work on the hearts of the cat, sheep, rabbit, frog, necturus, and

amphiuma. In this report only the first part of the problem will

be treated, i. ¢., the fine structure of heart muscle as illustrated in

the heart of a dog.

The material used was obtained from a young dog instantly killed

by an accident. Pieces of the heart wall were put into various

* An informal report of the results embodied in this paper was given before the

Histological Seminary, Cornell University, May 7, 1901.

36 GERTRUDE A. GILLMORE

fluids: Zenker, Flemming, picro-aceto-sublimate, picric alcohol, 67%

alcohol, Perenyi, and others. Of the fixatives used, Flemming and

picro-aceto-sublimate have proved the most satisfactory. The ma-

terial was carefully dehydrated, imbedded in paraffin, and cut into

sections of from 3 to § microns in thickness. Some of the material

was stained with Heidenhain’s haematoxylin, and some with Wotter’s

haematoxylin, first mordanted in vanadium chloride. The latter

stain was the more satisfactory. The sections were mordanted for

three hours in a solution consisting of two parts of a 10% solution

of vanadium chloride and ten parts of a 5% solution of acetate of

aluminum. They were then stained for three-quarters of an hour,

instead of the longer period recommended in Lee. The material was

differentiated in absolute alcohols acidulated with 4%, 4%, 4%,

and 4% of hydrochloric acid. While the sections were trans-

ferred successively through the four differentiators, they were care-

fully watched every two minutes. They were then cleared in ber-

gamot oil and mounted in balsam. The new methods recommended

in Heidenhain’s last paper (’o1) have not been used, since much of

my material was prepared several months prior to that publication.

Any later use is now precluded by his request that no one publish

any results obtained on muscle by his new methods until his com-

plete work appears. The effect of iron haematoxylin on muscles is

well known. With vanadium chloride and haematoxylin the trans-

verse disc, Krause’s membrane, and a dark line crossing the cell ce-

ment are stained a bright blue. The sarcolemma is faintly tinted a

light blue. Since this stain is much more brilliant than iron haema-

toxylin and tinges more structures, it has proved the more satisfac-

tory one to use.

In the writer’s well-fixed preparations of heart muscle few wide

breaks occur in the tissue and these breaks are filled with connective

tissues, or capillaries. One does not find the commonly figured wide

spaces between the fibers, but a mass of fibrils from the formerly so-

called cells, whose existence is now doubted by Ebner, Heidenhain,

and others, appear to blend together and form other fibers. (See

figs. 1 and 3.) Heidenhain has found the same condition in the —

human heart (’99). He thinks that one does not find cells anasto-

mosing by lateral branches, but that the “ general type of lateral con~-

nection is by broad regions of fusion between parallel fibers.” From

a glance at the right of figs. 1 and 3, one sees that by the confluence

FINER STRUCTURE OF HEART MUSCLE OF DOG 37

#f two masses of fibrils from two adjacent cells a third so-called cell

is formed which lies in a line intermediate between the other two

_ cells. Repeatedly these masses of fibrils appear to blend in a plane

above or below that on which one’s sections were cut. (See fig.

3-) Frequently small breaks occur parallel with the fiber but ex-

7 an

few fibrils apart. Often any wide lateral break between cells is two

or three fibers apart. But in these spaces several small, more or less

parallel breaks may occur. In consequence of these conditions, it

seems to the writer difficult, or even impossible, to give distinct lat-

_ fal boundaries for cells. However from a careful comparison of

____ long and cross sections of the fibers, one usually finds near its center

nuclei at more or less regular intervals. Occasionally one finds two

___ muclei close together. In every case there is some cytoplasm sur-

‘founding the ellipsoidal nucleus and extending out from it, often in

@ more or less cone-shaped mass. (See fig. 2.) The areas en-

closed between two cement bands are variable ; occasionally they are

shorter than the length of a nucleus, usually several times its length.

(See the extreme upper and lower portions of fig. 3.) In the dog’s

heart, the writer has never found the bands less than three or four

_ Segments apart. Heidenhain, however ('o1), states that in the

human heart one sometimes finds one segment (Z-Z)* enclosed be-

_ tween two bands. This fact, together with the already observed

__-—«-€ontinuity of the fibrils through the cement—Ebner (’00), Hoyer

(or), Heidenhain (’or), and figure by Szymonowicz (’or)—he

thinks argues against the cement bands being considered as distinct

cell boundaries. Godlewski ('o1) has also come to the conclusion

that the cells of the myocardium develop as a syncytium. The

__ writer has also found in the dog’s heart indications of this same con-

tinuity of the fibrillae. This point will be discussed more fully later

when the cement bands are described in detail. The more one stud-

ies heart muscle the less does the idea of separate cells seem tenable.

_ Wherever large or small breaks occur in the muscular tissues of

the heart of the dog, cat, sheep, or amphiuma, one finds along the

Throughout this paper the writer will use Heidenhain's nomenclature: Z =

_ _Krause’s membrane ; ¢ = transverse disc; gh = the light area which separates the

____ Seansverse disc into two parts; J == lateral disc; and M =the middle disc.

=e 4

38 GERTRUDE A. GILLMORE

edge of the fiber a distinct sarcolemma. The presence of this struc-

ture in heart muscle was reported by Hoyer (‘o1), recently by Heid-

enhain and others. MacCallum (’97) has described in the human

heart a condensation of the sarcoplasm, but does not seem to con-

sider it the same as the sarcolemma of skeletal muscle. He thinks

each fibril is surrounded by such a condensation. Sometimes be-

tween two adjacent fibrils it is double. It then appears raised in

folds. At other times between two fibrils there is a single layer

with no wavy outline. Heidenhain, on the other hand, having so

recently thoroughly studied the human heart, describes the same

structure as a sarcolemma. Where this structure appears in suc-

cessive parallel breaks, which are only a few fibrils apart, he thinks

indicates the presence of partially developed fibers. In the hearts

studied by the writer, the sarcolemma appeared as a narrow, usually

wavy band of homogeneous, hyaline sarcoplasm. (See figs. 2 and

3.) In this band Krause’s membrane terminates. When the sarco-

lemma is raised in waves Z ends in the depressions between the

waves. One wave extends from Z to Z. This arrangement seems

to be usually the case, except possibly where the cement intervenes.

The height of successive waves, where the discs are in like phases,

appears to be the same. In thin sections of the hearts of the dog,

sheep, and cat the relation of Z to the sarcolemma is very apparent.

Where the fibrils border the cytoplasm surrounding the nucleus, one

finds again the sarcoplasm raised in arches, at the base of each of

which Z ends. It is interesting to note that in insects where so much

muscular effort is put forth, one finds a sarcolemma like that in the

heart muscles of vertebrates. The relation of this structure to the

cement bands will be described later.

The cement bands extend occasionally across a fiber, but usually

one finds the staircase appearance fully described by Heidenhain

(or). (See figs. 1 and 2.) The steps seem to lie edge to edge

and seldom to overlap. They may go up and then down, or each

step may be one or several segments higher than the one below.

Occasionally there appears to be in the dog’s heart some slight varia-

bility in the breadth of the bands. Usually they are slightly nar-

rower than the area from Z to Z, but occasionally as broad. In the

same section there is little or no variation in the bands. The number

of fibrils which are crossed by one of the steps may vary from those

which constitute half or three-quarters of a fiber to a single fibril.

- FINER STRUCTURE OF HEART MUSCLE OF DOG 39

< ig ¢ discs Crossing the segments just above or just below a step

become continuous with those crossing other fibrils which are crossed

___ by other steps. When the cement bands in the dog’s heart are ex-

_ amined more carefully, they appear to be composed of rod-like

Bodies, each of which lies in the same straight line as a fibril. To

rod seems to be a continuation of a fibril. These

rods, as shown in figs. 5¢ and 5d (Pl. V), do not extend straight

across the band, but often either separate or come close together

towards the middle of the cement area. Extending across the cen-

ter of the cement band is a dark blue line. (See fig. 4.) This

line stains as does Z. Where small breaks occur between fibrils and

‘cement bands, one often sees such a condition as shown in fig. 5,

_ where Krause’s membranes appear to become continuous with this

blue line. Where a wide break occurs and the single blue line can

De seen, the sarcolemma appears to arch down in the middle of the

_ cement band and the blue line to end in the depression. Again one

sometimes finds the cement band crossed by two blue lines which

__ afe quite close together. One then finds that both lines appear to

_ terminate in the sarcolemma (see fig. 5¢), or as already shown in

fig. 5b, each blue line appears to become continuous with an inter-

_ mediate disc (Z) lying just beyond the cement band and the one

_ mearest on a level with the blue band. From a more careful exam-

"ination of the band, it would look as if the blue might be produced

_ by the staining of the delicate threads which seem to weave in and

out between the rods of which the cement seems to be composed.

_ After comparing the writer’s sketches of cement areas with those of

___-Szymonowicz (’o1) and MacCallum, it was evident that they re-

__ semble more closely the latter author's illustrations of the cement

q bands in the human heart. He states, however, that he was only

Same 02 fad in the human Beart a single line crossing the cement

(MacCallum, ’97). At first the writer thought that probably the

MES bios lines were Krause’s membranes, which are supposed to

_ border each side of the cement bands. This explanation seemed

“ since the lines ended in the sarcolemma and stained as did

Z. But of this point the writer is uncertain. If these lines are

Krause’s membranes, why does one so frequently find the cell cement

crossed in the center by a single blue line? Is this effect caused by

"a Slight obliquity in the cutting of the sections? If this is the case,

the obliquity was not apparent. Since these lines both stain and

4° GERTRUDE A. GILLMORE

bear the same relation to the sarcolemma as does Z, they would seem

to be of the same nature. But are they really the same structure?

The writer is confident that in the dog’s heart one may find the ce-

ment band crossed sometimes by one, and sometimes by two blue

lines. What they are it seems impossible to say, especially since the

nature of the cement band is not fully understood. MacCallum

and Przewoski (’93) consider the bands intercellular bridges. Ebner

thinks they are contraction areas; and Heidenhain (’or), in his

last article, has attempted to disprove both hypotheses and has

claimed that they are growth areas; that there segments are being

formed as the heart increases in size. Whatever hypothesis one

may hold, it is interesting to note that all the discs between the two

cement bands appear to the writer to be in like phases. When the

discs appear to change their forms, a cement band intervenes.

From a glance at figs. 4a to 4c, one sees that all the discs, except

perhaps M, found in skeletal muscle, occur in the heart muscle of the

dog : Krause’s membrane (Z),the lateral disc (J),the transverse disc

(q), the light area which separates g into two parts (gh), and pos-

sibly the middle disc (M), is present. Z takes a deep blue stain

with haematoxylin, does not seem to vary in thickness, and extends

as a continuous membrane not only from fibril to fibril across one

fiber, but also appears to cross continuously two or even three and

possibly more fibers. It is interesting to examine places where fibrils

have been pulling a short distance apart, for there one sees Krause’s

membrane stretching across the intervening space. The relation of

Z to the sarcolemma has been dwelt upon. On each side of Z is

the lateral disc (J). It is isotropic, more fragile, and less deeply

stained than g. It appears a little darker than the ground substance,

but lighter than gh. It does not stain with haematoxylin. The

width of J varies greatly, as will be seen from figs. 4a and 4b, but it

never entirely disappears. The transverse disc is anisotropic and

stains deeply with haematoxylin. It varies greatly in width and out-

line. In fig. 4a it extends almost the entire length of the segment.

The outline in long section is then distinctly that of an oblong. As.

J decreases in size, the edges of q round off and one gets the bead-

like forms shown in fig. 4b. In figs. 4c and 4d, one sees q crossed

by the light area, thus forming gh. Whether one can consider that

in fig. 4c the narrow area is M, seems difficult to determine if one

is unable to stain it. Heidenhain, by his later methods, is able to

FINER STRUCTURE OF HEART MUSCLE OF DOG 41

color this dise and shows that M is present in the human heart mus-

cles. He considers it the complete analogue of Z, but more delicate

}mature. As g grows narrower, J increases in width. Heidenhain

('99) thinks that J and q stand in the closest connection with the

function of contraction. The bead-like appearance of q he considers

due to the contraction of the contour lines. Since the transverse

discs crossing one fiber lie in the same straight line as those cross-

‘ing parallel neighboring fibers, one may often trace row after row

of these discs extending straight across the field of the microscope.

_All parallel fibers do not always show like discs in like phases, as is

_ evident from fig. 3, although they are often in like phases.

| -Whether the various appearances of the transverse and lateral

discs indicate extraction of the stain or whether they indicate phe-

“nomena of contraction, the writer does not know. As already stated,

if like phases, unless the conditions of the discs on the lower edge of

_ fig. 2 is an exception. If the fibers are continuous and if the phases

__ of the discs indicate contraction phenomena, why does the wave con-

_ traction stop at the cement band? Why does the impulse gradually

die out?

i _ From what has been said one sees that in the dog’s heart, as in

adjacent cells blend together to form new fibers ; the whole making

a complex network. Again, where spaces occur between fibrils, one

___ sees along the fiber’s edge a narrow, wavy condensation of sarco-

_ plasm resembling the sarcolemma of insect muscle. In this struc-

ture terminates Krause’s membrane. Near the center of the fibers

__ at more or less even distances apart lie the nuclei. Occasionally two

nuclei lie a short distance apart and are connected by a slender col-

umn of cytoplasm. The cement bands resemble a series of blocks

_ €rossing the fibers. The distance between the bands and the number

___ Of fibrils crossed by a portion of a band, or step, may vary greatly.

__ The cement area appears to be crossed by rods which look as if they

___were the ends of the fibrils. Through the center of the cement area

extends one, or occasionally two, blue lines. These lines give indi-

_ tations of becoming continuous with Z. In places, also, these lines

appear to end in the sarcolemma as does Krause’s membrane. At

times, in very thin sections, one gets the appearance of an interlacing

network crossing the rods. Between two cement areas all the discs

42 GERTRUDE A. GILLMORE

appear in like phases. The discs which the writer has found present

are Z,J,q, and gh. M may be present. Z, or Krause’s membrane,

is of uniform thickness, stretches continuously from fibril to fibril,

crossing often more than one fiber, and terminates in the sarcolemma.

If the sarcolemma is wavy, Z terminates in the depressions between

the waves. J and gq vary in size but never entirely disappear; as

the one increases, the other decreases in size; frequently g is bead-

like in form; and it is often crossed by a light area, gh, which cuts

the transverse disc into two parts. The breadth of gh varies. As it

increases in width, the parts of the transverse disc become bead-

like.

The writer wishes to acknowledge her indebtedness to Professor

S. H. Gage and Professor B. F. Kingsbury. To the former she is

indebted for encouragement and assistance in the preparation of

material; to the latter for his many helpful suggestions and ready

sympathy. :

FINER STRUCTURE OF HEART MUSCLE OF DOG 43

93 Sur le mode de réunion des cellules myocardiques de l'homme.

Also Szymonowicz and MacCallum. Histology and

Anatomy, Phila. and N. Y., 1902.

44 GERTRUDE A. GILLMORE

EXPLANATION OF PLATES

Plate Il

Fig. 1. Heart muscle of the dog showing the interblending of fibrils, the

relative position and shape of the cement bands, and cross striations,

Fig. 2. Same as fig. 1, but showing the relation of the sarcolemma to the

muscle fiber and to Krause’s membrane.

Plate IV

Fig. 3. Shows cross striations in detail and their relation to those of

neighboring fibers and to the cell cement.

Plate V

Fig. 4. Various appearances of the discs. 4a. The segment, Z-Z, nearly

filled by the transverse disc, g. 4b and 4c. Variation in the relation of the

transverse disc to the later discs. Two bead-like forms which q may assume.

4d and 4e. The transverse disc crossed by the light area forming gh.

Fig. 5. Cell cement. Relation of blue lines crossing the cement to

Krause’s membrane. s, sarcolemma; +, cell cement; y, blue lines; z, Krause’s

membrane. 5a, cement crossed by one blue line. 5), cement crossed by two

blue lines.

Fig. 6. Appearance of the cement band and the relation of the blue lines

and the sarcolemma to the band. +, rods; y, blue lines; z, Krause’s mem-

brane; s, sarcolemma.

;

PLATE Ill

, Ck

ay)

PLATE IV

be ii Jit it rrr Frees

[eet wee eeee ee ~: jg ta ek tat i

rrr): ttt. T 1) Lek, penan enemas aos a0 os bs

fee ve. es

we Yl -

a ene ed h _ ie, | a

PLATE V

COT

anid

CLT. Hines

Fig. 4c os

Fig. 5a Fig. 56

- ADDITIONAL NOTES ON THE CLADOCERA OF

NEBRASKA

By CHARLES FORDYCE

ee en eee ee

Nebraska (Fordyce, 1901), the author has been extending his survey

of the state and making collection in localities not covered in the

previous report ; aside from the material obtained by personal effort,

are due to Dr. R. H. Wolcott and Miss Caroline E.

_ Stringer for some valuable collections furnished by them. An ex-

a. ‘amination of the material reveals nineteen species in addition to the

Brotogical. Compersons |

two miles of the village. The water is cold, clear and has a

_ depth varying from two to five meters. The phytoplankton and the

higher aquatic _— are abundant. The pond is well located and

a for zooplankton, but for the fact that the stream is

____ swift, giving the water found in the mill dam an appreciable current

species shown in the subjoined table, but many reported in the table

ot ion, fori here

____ Little Alkali Lake lies about thirty-five miles south of Valentine

in one of the most interesting lacustrine districts of our state. The

Slike hore fo shout fourier handcod mnotera eheve the soa tovel

_ The lake is about five hundred meters in diameter, and attains the

_ depth of two to three meters. The plant life is not abundant; a few

_ Clusters of cat-tails and rushes represent the higher aquatic plants,

a. 45

46 CHARLES FORDYCE

while the algae are confined to a few Volvocinae and to a few Dia-

tomaceae.

Hackberry Lake is a broad sheet of water lying three miles north-

west of Little Alkali Lake. It has an average diameter of about

four thousand five hundred meters and a depth of from one to two

meters. The water contains an abundance of higher aquatic plants,

as well as the lower forms; Spirogyra, Zygnema, and other types of

filamentous algae are in great abundance.

St. Mary’s Lake is located seven and one-half miles south of

Aurora. It has a diameter of about four hundred and fifty meters

with a depth rarely exceeding one meter. The bed is composed of

rich alluvial soil with an abundant growth of rushes and other higher

plants. The phytoplankton is scarce ; Closterium among the desmids,

and two or three types of Volvocinae are the leading representatives.

The collecting ground at Sidney is a small shallow lake one

and a half miles southwest of town. The region is generally

sandy with a vegetable plankton confined almost wholly to diatoms.

The zooplankton is represented by two genera, Alona and Chydorus.

The material from York was found in a small turbulent pond on

the east side of the city. The water is poorly lighted and almost

destitute of plant life. Moina brachiata is the only cladoceron in the

collection ; this is not abundant.

Pilger Lake is a body of water in the form of a “ cut-off” on the

Elkhorn River at a point one mile east of Pilger. The lake contains

many higher plants, and among the lower Fragillaria and Oscillaria

are very abundant; the Rotatoria are also very numerous. The

zooplankton is rich in numbers.

Stringer’s Lake is a small sheet of water, located two miles east

of Wayne. The lake is spring fed, comparatively cold, and very

poor in vegetable plankton. The animal plankton, like the vegetable

plankton, is limited.

The following table indicates the geographic distribution of species

found so far as these are new to Nebraska; Pleuroxus uncinatus

Baird is new to this country and the following are new to science:

Daphnia magna var. americana.

Leydigia trichura.

“f

‘

ADDITIONAL NOTES ON THE CLADOCERA OF NEBRASKA 47

Valentine

Little Alkali

Pilger’s Lake

Stringer’

York

* (St. Mary’s Lake

DAPHNIA MAGNA Var. AMERICANA Nn. var.

Bai Plate VI, fig. 1

Daphnia magna Strauss is described quite in detail by Richard

(96: 192-197; Pls. 20, fig. 1; 24, figs. 6, 13); the species is very

_ generally distributed over the Old World, but up to this time, as far

as can be learned, is not reported from America. Since this species

has very pronounced variations dependent upon food and the differ-

ent biological conditions under which it has been found it is not with-

out hesitation that the writer suggests a new variety; the represen-

_ tatives of the species here are, however, so remote and under such

_ different environmental conditions from their kindred in the Orient

that such wide variations in characteristics as have been found are

not unexpected.

The female has an average length of 3.5 to 4.5 mm. and a height

of 2.5 to 3 mm. The carapace is very distinctly sculptured with

fine, quadrate areas : the caudal spine is in the line of the dorsal mar-

48 CHARLES FORDYCE

gin and spinulose, while in many specimens it curves ventrad (fig.

1): in length it is very variable and in old females absent. The

ventral margin is decidedly more convex than the dorsal, both being

armed from near the middle posteriad with spinules of increasing

length: the spinules of the ventral series are continued on the caudal

margin, where they are very thickly set: along the middle of the

ventral margin for an interval equal to about one-tenth its total

length is found a series of very fine plumose hairs. There is no

appreciable sinus between the head and the body. The upper and

anterior margins of the head are uniformly curved, there being a

slight projection below and in front of the eye and a noticeable con-

cavity in the ventral margin between the head and the beak. The

antennae of the first pair are conical and reach the extremity of the

beak ; the sensory hairs are coarse, short and rarely exceed seven in

number. The fornix is very prominent, the eye medium in size with

large distinct lenses ; the pigment fleck is small and triangular. The

antennae of the second pair are strong and spinulose, the apical end

of the basilar joint, as well as each articulation of the rami, is fur-

nished with short teeth; the dorsal margin of the ventral ramus and

that of the distal articulation of the dorsal are provided with long

sparsely set hairs. The swimming setae are biarticulate and densely

plumose, the hairs being set almost perpendicularly to the shaft. The

digestive canal is of the usual daphnid type with the gastric caeca

long and convoluted: the most characteristic feature of this species

is the post-abdomen, the dorsal margin of which is interrupted near

its lower part by a sinuosity: there are from nineteen to twenty-three

anal teeth,of which seven to nine lie below the sinuosity and twelve to

fourteen above ; these teeth decrease in length dorsad in each series ;

besides these teeth the post-abdomen is densely studded with sharp

spinules which are in the lower half grouped in twos and threes.

The terminal claws are long, distinctly curved, and provided with

two combs of fine secondary teeth on the proximal half and a series

of fine spinules on the distal. There are four abdominal processes,

the anterior being long, slender and curved forward, the second is —

heavy conical and about half as long as the first; the last two are

short nodules and like the second distinctly spinulose. The abdom-

inal setae are short and biarticulate, with the distal portion plumose.

The males are about half as large as the females, measuring 2 to

2.75 mm. long and 1 to 1.4 mm. high. The plumose hairs of the

ADDITIONAL NOTES ON THE CLADOCERA OF NEBRASKA 49

a ventral margin extend forward to the head. The eye is compara-

___ tively larger than it is in the female and is set farther forward, giv-

serrate. The claw of the first foot is extremely long, having the

um. The post-abdomen is curved forward on its anterior margin

a Comparisons

_D. magna Strauss. D. magna var. ameri-

cana n. var.

__&. Valves often as broad as long. Never.

2. Size—female 4 to 5 mm. long. Size 3.5 to 4.5 mm.

: 3. Forehead not prominent. Prominent.

4. Anterior margin of head straight. Convex.

____ §. First antenna does not reach the extrem-

ee ity of the beak. Reaches extremity.

___ 6, Abdominal processes all hairy. Posterior three only.

__- J. Post-abdominal teeth of

(a) distal series 4 to 6, (a) 7 to 10,

(b) proximal series 10 to 12. (b) 12 to 14.

LEYDIGIA TRICHURA fn. sp.

Plate VI, figs. 2, 3

___—-* Female.—This species attains a length of 0.8 mm. and a height

_ of 0.55 mm. The general form is elliptical and very similar to L.

| fimbriata Fordyce (01: 161-162, Pl, 23, figs. 11 to 14). The dorsal

| margin of the carapace is nearly straight in its middle third: the

I ascgioe of the res

- of the valve are uniformly curved (fig. 2).

z The ventral margin is ornamented through its entire length with

50 CHARLES FORDYCE

densely set plumose hairs: the ventral fourth of the posterior margin:

is provided with short, fine spinules. The valves are indistinctly —

marked by longitudinal striae. The head is comparatively large and

projects obliquely downward, the forehead being nearly straight.

The eye is small and approaches the anterior margin of the head,

the crystalline lenses are buried in the pigment; the pigment fleck

is triangular, about fifty per cent larger than the eye and is above

the middle point between the eye and the rostrum. The antennae

of the first pair are prominent, fusiform, and inserted immediately

under the pigment fleck; they extend considerably below the ex-

tremity of the rostrum. The sensorial hairs are few and about half

as long as the body of the antenna, from whose anterior margin long,

straggling, stiff hairs emerge. The antennae of the second pair are

robust and when flexed reach nearly two-thirds the distance to the

posterior margin of the carapace. They are ungraceful in appear-

ance, having a stunted basilar joint much constricted at the proxi-

mal end. The rami are almost equal in length, each having three

apical, biarticulate, and sparsely plumose swimming setae; a strong

sharp thorn accompanies each set of setae. A brush of similar

thorns diverges from the antero-distal part of the first and second

articulations of the ventral ramus, two appear on the anterior mar-

gin of the first article of the ventral ramus and one emerges from

the extero-distal end of the first article of the dorsal ramus.

The digestive canal is convoluted and has a very narrow lumen.

The post-abdomen is very prominent, having both the anterior and

posterior margins convex, the latter being conspicuously curved and

armed with several series of spines and thorns. From the distal

half of this margin there come eight or nine long curved spines

decreasing in length dorsad (fig. 3); each is fortified at the ex-

terior side of its base by one or two short curved spines. The series

of long spines is continued dorsad by a row of fifteen to sixteen

shorter straight ones. The series of anal spines just mentioned is

set in considerably from the margin. The interval immediately

along the dorsal edge between the lateral rows of spines is densely -

studded with sharp, stout thorns which extend to a slight sinuosity

found at the beginning of the upper third of the dorsal margin: from

this point extends a row of spinules followed by a number of nodules

from the largest of which the long abdominal setae emerge. Each

side of the anterior margin of the post-abdomen is marked by three

ADDITIONAL NOTES ON THE CLADOCERA OF NEBRASKA 51

+o DAPHNIA PULEX var. NASUTUS Herrick

_ The animal described and figured by Herrick (84:57, Pl. N. figs.

1 to 4) under the above name is found in St. Mary’s lake. It has

an average length of 1.1 to 1.2 mm. The peculiarity of the beak,

to Herrick the appearance of the “ Roman nose” is no-

ticeable in the forms examined. The abdominal processes are hairy

and the two anterior ones less divergent than is indicated in the orig-

imal figure. There are twelve anal teeth curving upward. The claw

_ is rather strongly curved and armed at its proximal half with twelve

DAPHNIA SCHOEDLERI Sars

Sleen SNE Se ents Stieaairs Seance’ (95°

mens measured have an average of 1.7 mm. in length and only 0.95

mm. in height; in other respects the animal agrees with that of

SIMOCEPHALUS SERRULATUS Koch.

_ Our specimens differ from the described forms, particularly Birge’s

S. serrulatus which he formerly called S. americanus (78: 82-84, PI.

1, fig. 6) in having the antero-frontal portion of the head to which

the thorns are attached rounding rather than in the form of an acute

angle. The caudal teeth emerging from the truncated portion of the

post-abdomen are, in the animals observed, fourteen in number,

52 CHARLES FORDYCE

gradually decreasing in size from the claw posteriad ; in other regards

our form does not differ from those described.

MOINA BRACHIATA Jur.

A few of these were found in a small pond at York. It is with

some doubt that they are referred to this species as they do not answer

exactly to the characteristics of any of the Moina group, but they

approach so nearly Stingelin’s diagnosis (95: 219-220, fig. 20) that

I venture to put them under the above name rather than to assign

them a new place. The shell is indistinctly marked by lines crossing

each other irregularly, very similar to the sculpturing of the shell in

M. Lilljeborgii Schoedl. as figured by Lilljeborg (53:38, Pl. 2, fig.

4f). The males bear a striking resemblance in outline and in form

of the antennule to the male of M. affinis Birge (93: 290-291, Pl. 10,

fig. 7). Our species departs from Stingelin’s description in the fol-

lowing particulars :

Swiss forms Nebraska forms

Length—female 1.2-1.6 mm. 1.5-1.65 mm.

male 08 mm. 0.88 mm.

Caudal teeth 10 II-12

ALONA CosTATA Sars

This form approaches very closely to the diagnosis and figure of

Steuer (01: 124, Pl. 5, fig. 17). It differs, however, in having only

ten anal teeth and in having above these a row of very closely set

spinules. In points of comparison with A. guttata Sars our speci-

mens correspond to Steuer’s description.

ALONOPSIS LATISSIMA Kurz

These are abundant in the collections from St. Mary’s Lake,

Aurora: the average length is 0.45 mm. The general form agrees

with that of Herrick and Turner (95: 232-233, Pl. 61, fig. 9) and

with Birge’s description under A. media (78: 108, Pl. 1, figs. 14, 15).

By these men no mention is made of the fact that the lower three anal

spines are decidedly larger than the others; this is characteristic of -

the Manitoba specimens of Ross (97 :162), as well as of those found

here.

PLEUROXUS UNCINATUS Baird

A few typical representatives of this species, not hitherto reported

in this country, were found among the collections from Hackberry

ee en

" of pan} St. = ee a, oat

ee a ee a ee ee | ll

ADDITIONAL NOTES ON THE CLADOCERA OF NEBRASKA 53

e. The animal agrees in general with Baird’s description

2 135, Pl. 17, fig. 4) but differs in having the posterior margin

0 Bris Gites Chgucae tts Neck ts las cannes’

Wargin, as given in Baird’s diagnosis. The beak is less procurved

an is indicated by the description and the original figure.

KS Th general outline of the body approaches Baird's description of

trigonellus (50: 134, Pl. 17, fig. 3). Baird does not give the

th of his specimens but Steuer finds the average length to be

3 to 0.568 mm. (o1: 126-7, Pl. 5, fig. 23 a, b), while our rep-

mtatives measure from 0.7 to 0.8 mm. in length.

ae Cuyporus ruGuLosus Forbes

- This little animal reported in my former paper (01: 169, 170) as

} distributed over Nebraska, but as differing in some

. ticulars from Forbes’ description (90: 712), has been found

mg the collections from Sidney; the specimens of recent collec-

= ae ce aemeeny © Hosber’ Aagnosls and Sears,

aa Orner Spectes

Oe oiled Sats elnidk and telterid to ts the ahove notes,

ee so perfectly with the descriptions and figures of American and

writers as to make comment upon them quite unnecessary.

WORKS CITED

Barren, W.

so. The Natural History of the British Entomostraca. Ray Soc.

Brice, E. A.

78 Notes on Cladocera. Trans. Wis. Acad. Sci., IV, 77-110, 2 pl.

93. Notes on Cladocera, III. Trans. Wis. Acad. Sci., IX, 275-317, 4 pl

Fornes, S. A. a.

go. On Some Lake Superior Entomostraca. U. S. Comm. of Fish and eS

Fisheries, part 15, Report for 1887, 701-718, 4 pl.

Forpyce, CHas.

o1. The Cladocera of Nebraska. Trans. Amer. Mic. Soc., XXII, 119-175, —

4 pl.

Herrick, C. L. t

84. A Final Report on the Crustacea of Minnesota included in the Orders

Cladocera and Copepoda. tath Ann. Rep. Geol. and Nat. Hist Suro

vey, pt. V, 191 pp., 30 pl. uf

Herrick, C. L., and Turner, C. H.

OS. Syaopele ofthe Rutuensstiece af Minnestts with aia i.

related species comprising all known forms from the United States a

included in the orders Copepoda, Cladocera, Ostracoda. Zool. Ser. II,

State Geol. Nat. Hist. Survey Minn., 525 pp., 81 pl.

Liiyenorc, W.

53. De Crustaceis ex ordinibus tribus: Cladocera, Ostracoda et Copepoda,

in Scania occurrentibus. : a

Ricwarp, J.

" Proc. lows Acad Sel, 2¥) 154-162.

Srever, A.

ot. Die Etomostrakenfauna der “alten Donau” bei Wien. Zool. Ty

Syst., XV, 168 pp., 12 pl.

STINGELIN. 2.

95. Die Cladoceren der Umgebung von Basel. Rev. Suisse Zoo, 1,

161-274, 4 pl.

EXPLANATION OF PLATE VI

Fig. 1. Daphnia magna var. americana, lateral view of female. X 20.

Fig. 2. Leydigia trichura, lateral view of female. X 90. .

Fig. 3. Leydigia trichura, post-abdomen of female. X 300.

PON THE OCCURRENCE OF HAEMOSPORIDIA IN

THE BLOOD OF RANA CATESBIANA, WITH

AN ACCOUNT OF THEIR PROBABLE

LIFE HISTORY

By JAMES H. STEBBINS, Jr.

WITH TWO PLATES

Twenty-four small bullfrogs captured last fall on Long Island,

’., furnished the material for this investigation. Upon exami-

1 these frogs were found to be quite heavily infected with

while in several of the number trypanosoma were also

found. The blood was examined in the fresh and stained conditions,

and several forms of parasites were found to be present, which for

convenience of reference will temporarily be referred to by number.

_ One of the parasites which we will designate as No. 5 differs so

from any of the others that I consider it to be a dis-

species, and will therefore exclude this one, and confine my

ks to a description of the other four forms which will be

n to belong to one and the same species, only in different stages

lise life history.

_ Parasite No. 1.—This parasite was found very plentifully in the

. ed blood corpuscles of the frogs examined, but also is occasionally

_ found in the leucocytes. It is a small gregarine-like organism, some-

_ what crescent-shaped; pointed at both ends, though at times some

ne Beet of cme ceneeey, and slightly enlarged, and

d at the other.

It is provided with a nucleus, nearly centrally located, consisting

_ larly in clumps, or scattered over the body of the parasite. The body

ccasionally the parasite may be found with a vacuole on either side

f the nucleus. The length is 18.5 #, and the diameter 4.6 p.

56 JAMES H. STEBBINS, JR.

The organism stains faintly with the Wright stain, but, strongly

with the Goldhorn polychrommethylene blue and eosin stain, the

latter staining the body protoplasm a light pink, and the chromatin —

granules a strong and fiery red.

This parasite (PL VII, fig. 2) which I have christened Haemo-

gregarina catesbianae, and which later will be shown to be the

asexual organism, exerts but little if any action upon the invaded

erythrocytes. Occasionally a red cell may be found whose nucleus

has been displaced to one side, but as a rule they are not displaced,

nor have I ever noticed any other injurious action upon the same.

There may be multiple infection with one, two, or three parasites.

The organism may be found within the red corpuscles completely

elongated, curved up crescent-fashion, with the ends folded up

U-shape, or rolled up into a spherical form, depending upon what

stage of the asexual cycle it has entered.

Parasite No. 2, or Cytocyst—(Plate VII, figs. 5 and 8.) Strictly

speaking, this is not a distinct or separate parasite, but merely one of

the transformation forms of the previously described organism, and

represents the encystation stage of the same. This cyst, properly

speaking cytocyst, varies considerably in shape and size, though the

spherical shape seems to predominate, but it is sometimes found of an

ovoid shape. It is surrounded with a thick membrane, which stains

of a deep purplish brown color with the Goldhorn stain, while the

body of the cytocyst takes a light pinkish shade.

This cytocyst, in reality a schizont, during the later stages of its

growth, will be found to contain numerous small merozoites, sur-

rounding a small amount of residual protoplasm, which stain of a

fiery red color with the Goldhorn stain (Pl. VII, figs. 5 and 8). The

erythrocytes are subject to multiple infection, as many as fou

schizonts in one corpuscle having been observed. The nuclei of the

invaded red cells are usually displaced a little to one side in order

to make room for the schizont, but they may frequently also be seen

with the nuclei in their normal position. Apart from this displace-

ment of the cell nucleus, no other pathological condition was observed. —

The diameter of this form is 7.18 p.

Merosoites-—(Pl. VII, fig. 1.) In addition to the foregoing, a

very small ovoid to spherical organism with a fiery red chromatin

granule centrally located, was frequently encountered in a free state

in the blood plasma, and was usually found quite close to the peri-

HAEMOSPORIDIA IN BLOOD OF RANA CATESBIANA 57

y of a red corpuscle. These bodies are the merozoites, which

escaped from the before-mentioned cytocysts after segmenta-

_ Parasite No. 3, or Microgametocyte—(Plate VIII, figs. 1-3.)

This parasite is found free in the blood plasma. It is a straight

or somewhat curved gregarine-like organism, sharply pointed at one

end, but, somewhat more rounded at the other, or anterior end. It

_ swims with its blunter anterior end forward. The average length is

_ 14.45 # and the diameter is 3.98. The body cytoplasm is slightly

al and stains of a pale pink color with the Goldhorn stain.

_ the present time I have been unable to discover how it is accom-

plished. All that can be observed is a slight indentation of the cell

protoplasm at the point of contact, when the latter seems to yield to

_ the pressure exerted by the parasite, and before one can realize it,

_ the vermicule has completely buried itself within the corpuscle, leav-

ing as a rule no other sign of its presence within other than a slight

writhing motion, and distortion of the cell protoplasm, but at other

times its movements may be easily followed. After a varying length

of time the parasite will leave its temporary abode, and when this

is about to occur, a protuberance will be formed upon the side of

the corpuscle from which it is going to emerge. This protuberance

_ gradually increases in length until the erythrocyte is drawn out,

pear-shaped. By this time the parasite has practically emerged from

the cell, but is still connected with the same by a long, very fine,

a ee” with which it tows the corpuscle around

for some distance before it is eventually ruptured. It not infre-

58 JAMES H. STEBBINS, JR.

quently happens that the parasite when emerging from the blood

corpuscle, tears away portions of the same, which it may carry

around with it for some time attached to the before-mentioned hya-

line thread. This parasite I take to be the microgametocyte of

Haemogregarina catesbianae. (PI. VIII, figs. 1, 2 and 3.)

Parasite No. 4, or Macrogametocyte-—(P1. VIII, figs. 4 and 5.)

This parasite exists both in the free state in the plasma, and within

the red blood corpuscles. Its length is 9.98 and its diameter

5.06. In the free state it is usually bean-shaped, fairly pointed at

one end, but bluntly rounded at the other. Its cytoplasm is quite

coarsely and heavily granular, with a well defined nucleus centrally

located, or nearly so, and a vacuole on either side of the same, about

midway between the nucleus and each pole.

The parasite takes the Goldhorn stain very readily, its cytoplasm

staining of a light pink, and the chromatin of the nucleus of a fiery

red color. It is not nearly as motile as the microgametocyte. This

organism I believe to be the macrogametocyte of Haemogregarina —

catesbianae.

The intra-corpuscular parasite is met with in several forms, de-

pending upon which stage of its life-cycle it has entered. (PI. VIII,

figs. 6-10.) It may be either bean-shaped, ovoid, or spherical, the

latter form representing its encystation stage. The nucleus of the _

intra-corpuscular parasite, or macrogametocyte, is considerably

larger than that of the extra-corpuscular organism. In the undi-

vided state it occupies the greater part of the body of the parasite,

and stains of a deep fiery red color, with the Goldhorn stain. At

times a small vacuole may be found at either pole, but this is not

of common occurrence. The cysts, in reality oocysts, are mostly — |

spherical, but vary occasionally, and are sometimes seen of an ovoid —

shape. They are surrounded by a dense, heavy membrane, which

stains of a deep purplish red color. (Pl. VIII, fig. 10.)

It has been an undecided question for some time, how cold-

blooded animals like frogs, turtles, snakes, etc., are infected with

haemosporidia, some taking the ground that infection is caused by _

the bite of a blood-sucking insect of some sort, while others believe

that infection is induced by taking the parasites through their food

into the digestive tract, and from there into the blood.

From my own observation, I know that the latter mode of infec-

tion is possible, as will be seen from what is to follow, though this

Sey ees ee ee

_ the small frog. This I think is fairly good evidence that infection

may take place through the digestive tract, by means of the food

An attempt will now be made to show in what is to follow, that

both schizogony, and sporogony take place within the blood cor-

puscles of the same host, though it has usually been assumed that in

cold-blooded animals, like the frog, etc., schizogony takes place

within the blood corpuscles, while sporogony occurs in the epithelial

cells of either the stomach, intestine, liver, or spleen of the same

Asexual Cycle of Haemogrezerina catesbianae.—The cytocyst

after segmentation (PI. VII, fig. 6) discharges its merozoites or

spores into the blood plasma, and these after wandering around at-

tach themselves to the blood corpuscles which by some means they

manage to penetrate. As soon as this has occurred, the young or-

ganism begins to grow, and is converted into a small worm-shaped

trophozoite, or schizont (Pl. VII, fig. 7) and this process is con-

tinued until the schizont has reached its full growth, when it will

have the characteristics previously alluded to. (Pl. VII, fig. 2.)

It now begins to fold over on its self, gradually assuming a U-shape.

(PIL. VII, figs. 3 and 4.) The two loops of the U now begin to

curve inwardly until they meet and coalesce, thus forming a sphere,

in which the line of suture is at first visible, but which eventually

disappears.

The schizont now surrounds itself with quite a heavy membrane

forming a true cyst (Pl. VII, figs. 5 and 8), and the chromatin

granules of the fragmented nucleus in turn become surrounded with

60 JAMES H. STEBBINS, JR.

a small body of protoplasm, at the expense of the cyst protoplasm,

thus forming the merozoites or spores lying about a small amount of

residual protoplasm. These after reaching full maturity, rupture

the cytocyst, and escape into the plasma, when they are once more

ready to invade fresh blood corpuscles. The foregoing represents

fairly accurately I believe the asexual cycle of Haemogregarina

catesbianae, which closely resembles the conditions obtaining with

Lankesterella ranarum, discovered in the blood of Rana esculenta,

and whose life history has been described in full by Hintze,* in 1902.

Sexual Cycle of Haemogregarina catesbianae—By analogy with

the haemosporidia of other cold-blooded animals on the one hand, and

with the acystosporidia on the other, it is believed that after many

generations of schizogony, the sexes become differentiated into

micro- and macrogametocytes, and that sporogony takes place some-

what as follows:

The nucleus of the motile, extra-corpuscular parasite, or micro-

gametocyte (PI. VIII, figs. 1 and 2), contains a number of chro-

matin granules. In the course of time the nucleus becomes frag-

mented, and its chromatin granules divide, and become scattered

throughout the body of the parasite. (PI. VIII, fig. 3.) Accord-

ing to Hintze (loc. cit.) the chromatin granules of the fragmented

nucleus now become the nuclei of microgametes, which are not

separated off simultaneously, but one by one in an irregular manner.

This I have been unable to verify in the case of Haemogregarina

catesbianae, though I suspect that some mode of fertilization must —

exist.

The unfertilized macrogametocyte which is found free in the

blood plasma (Pl. VIII, figs. 4 and 5) is likewise supplied with

a nucleus containing a number of chromatin granules. After fer-

tilization, whether this occurs in the manner suggested by Hintze

(loc. cit.) or by some other mode of conjugation, the macro-

gametocyte enters a red blood corpuscle, and then prepares for its

final encystation, by undergoing a number of changes. It first be-

comes more ovoid in shape, while the nucleus at the same time is con-

siderably enlarged. (PI. VIII, fig. 6.) It now begins to divide,

or segment (Pl. VIII, fig. 7), and its chromatin granules become

scattered throughout the body of the parasite. (PI. VIII, figs. 8

* Lankester, Quart. Journ. Mic. Sci., n. ser., Vol. 11, 1871, p. 387-

* Zool. Jahrb., Abth. f. Anat., XV, 4, pp. 693-730, 1902.

Z J oa

ee -_ =

we:

2 le

ee ry

tp Ae

ee ee rs hen =

a, fe ea

pe i

rer ee

FO ee ek cs ee

HAEMOSPORIDIA IN BLOOD OF RANA CATESBIANA 61

' a tainta: ok ten: Cokguensed dchein aoe apeno-

= ealate @ certain quantity of the cyst-protoplasm, and then become

_ sporoblasts, and these in turn are gradually changed into small rod-

_ shaped bodies, or sporozoites (PI. VIII, fig. 10), which when fully

_ Mature rupture the oocyst, and escape into the plasma (PI. VIII,

figs. 11 and 12), when they in turn will seek out and invade fresh

blood corpuscles. Such I believe to be the sexual cycle of Haemo-

_‘gregarina catesbianae, as it now appears to me, but it is possible

‘that after further study I may be forced to change my views.

SuMMARY

ee © Besmogregorine catesbianae is found in the blood of Rana

i: libibiens in several forms, among which may be mentioned, the

____ merozoite or spore ; the trophozoite, and cytocyst of the asexual cycle;

: _ the micro- and macrogametocytes, oocyst, and sporozoite of the

‘ha Infection may be induced by the food taken into the animal’s

_ digestive tract, though this does not exclude infection from other

causes.

__ Schizogony and sporogony occur in the red blood corpuscles of the

same host.

In the asexual cycle, multiplication of the species is brought about

_ by segmentation, or sporulation.

_ After many generations of schizogony, the sexes become differen-

tiated into macro- and microgametocytes, and conjugate by some

‘means yet undiscovered.

_ The extra-corpuscular macrogametocyte after fertilization, pene-

trates a red blood corpuscle, and becomes encysted, forming an

oocyst. The chromatin granules of the fragmented cyst-nucleus

appropriate a certain quantity of protoplasm, and become sporoblasts,

_ which in turn are converted into germinal rods, or sporozoites, which

_ when mature rupture the oocyst, and escape into the plasma, when

they in turn are ready to invade fresh blood corpuscles.

————

OUTLINE OF THE TUBE PLAN OF STRUCTURE OF

THE ANIMAL BODY

By J. S. FOOTE

_ The recognition of a definite plan underlying minute structures is

__a$ essential to the understanding of body construction as to that of

_ the tissues themselves. Tissues and cells do not exist separately in

_ the body, but are associated together as a cooperative community,

. | _ ach one bearing some particular relationship to all the others. If

_ design is omitted they are confusing and difficult to remember; but

____ if the design is known their various positions and varieties become

reasonable and easy to fix in the mind.

It will simplify matters very much if there can be found some one

plan of structure which is sufficiently common to the greater number

of organs of the body to become a fundamental constructive unit in

their formation. This plan of structure is to be found in the tube.

The development of the vertebrate kingdom of animals calls attention

to this fact. The small dimensions of the Protozoa enabled them to

continue themselves and exhibit their phenomena of life without the

presence of a central cavity; but as physiological division of labor

advanced in accordance with an increase of animal mass a time came

when a central cavity was necessary for the nutrition of the animal

and from that time the tube became the basis of structure. It was

foreshadowed as far back as Euglena viridis—a single-celled organ-

ism in which there was a slight indentation in the anterior end of the

creature and this was set aside as a food tube of entrance to the

small body. This simple tube in the low forms of life developing

into a complex system in the higher and highest forms indicates the

line of ascent along which animal progress has made its way, and we

find that the worm, tunicate, fish, amphibian, reptile, bird, and mam-

mal—chief divisions of the animal kingdom—all present the tube

as the fundamental structure of the body and of most of its viscera.

64 J. S. FOOTE

Embryological development also reveals the tube plan in all its

phases. After fertilization has occurred and the blastoderm has been

formed the whole period of prenatal life is concerned with the tube

formations and adjustments and when the creature is born, it is born

as a large tube within which are arranged in the form of viscera a

vast number of small tubes of all magnitudes. Both racial and in- —

dividual developments are tube developments and the kind of tube

produced depends upon the functional requirements of the animal.

The vertebrate animals are all practically constructed on the same

plan. They are composed of two tubes: the larger one containing

the thoracic and the abdominal viscera separated ‘by the diaphragm;

the other, the smaller, enclosing the brain and spinal cord.

THE VISCERA COMPOSED OF SYSTEMS OF TUBES

By a simple dissection we may satisfy ourselves that most of the

great system of the body are large tubes, as, for example, the res-

piratory, digestive, genital, urinary, vascular. By further analysis

these large tubes or systems are found to contain many small ones:

these small tubes are joined together in various ways by connective

tissue and form the organs. Thus the respiratory system is composed

of a large tube, the trachea, which divides and subdivides into a great

number of small tubes, the ultimate terminations of which are the

alveoli of the lungs. The digestive system is composed of a large

tube, the alimentary canal, the functional lining of which is arranged

in the form of simple and compound tubular glands which are small

tubes. The genital system is composed of a large tube containing in

its different divisions many small ones. The urinary system is com-

posed of a large tube some parts of which exhibit a most complex

system of small ones. The vascular system is composed of a large

tube which gradually decreases in size and forms small ones. The

secretory system is composed of large tubes which ultimately termi-

nate in a vast number of small ones, the acini. The viscera then are

for the most part aggregations of tubes and in many instances the

structure and function of one of them is sufficient for the whole.

If we can understand the structure and function of one air cell we can

understand the structure and function of the lung. If we know the

structure and function of one lobule of the liver or of any secreting

or excreting gland we know the structure and function of any of

those glands taken as a whole.

TUBE PLAN OF STRUCTURE OF ANIMAL BODY 65

THE VISCERAL TUBES ARRANGED IN FIVE CLASSES

hada psd nimi atagamn beat oar poset

_ classes. These five classes will be found to differ from each other

_ of the wall of any tube depends upon what is required of it. It may

___ be thick like the uterus or thin like a capillary, but in any case the

walls are composed of some combination of the tissues arranged in

__ the form of coats which may be divided into layers. For the sake of

convenience we may begin with that class which has the greatest

number of coats, which is four, and by a process of subtraction arrive

~ evated, one-coated, and one-layer tubes. In each tube structure the

__ €oat numbered 1, is the outside coat and the tube section is so placed

_ that its inner epithelial lining is uppermost. The coats of the five

4. Epithelial.

CoaTs OF A 3- Subepithelial.

_ Four-Coatep Tune.) 2. Muscular.

1. Connective tissue.

| b. Epithelial.

Owne-Coatep Tune. { aB }1wo layers.

One-Layer Tune. b. Epithelial.

It is thought that the coats and hence the structure of these tubes

will be better understood if they are based upon the functions of the

tubes.

66 J. S. FOOTE

In microscopical sections the purpose of the structures seen does

not appear and so no particular reason for the existence of any coat

is apparent and the coats are meaningless to the observer. If the

object of the tube is known then the structure becomes reasonable

and consequently more easily remembered. Structure does not in-

dicate function. For example there is nothing about a specimen of

muscle to show that it ever contracted nor would it be possible by

an examination of it carried even to the limits of microscopical in-

vestigation to prove that it could contract. But knowing that it

does contract its ultimate structure then becomes a reasonable one.

The same is true concerning any other structure. The various tube

structures or coats may be considered from this viewpoint.

Four-Coatep TuBE

The alimentary canal is the only tube of this class.

1. Connective tissue coat——This is a thin layer of connective tis-

sue in the form of a serous membrane which surrounds the tube for

the most part from the lower end of the oesophagus to the rectum.

This coat of the oesophagus consists of the connective tissue which

supports the tube and may or may not be considered a distinct coat.

By means of this coat the tube is supported by attachments to the

skeleton and provided with a blood and lymph circulation.

2. Muscular coat.—This is composed of two layers of muscle

throughout the whole length of the alimentary canal except at the

cardiac end of the stomach, where there are three. In the upper half

of the oesophagus the muscle is striped voluntary, in the other por-

tion smooth. Here a motor tube is required because progressive

motion of the contents in a certain direction is necessary. This can

be accomplished only by a contractile tissue and this must be ar-

ranged according to some definite plan. In most motor tubes, two

layers of muscle are sufficient, an external longitudinal and internal

circular. In a few tubes three layers are found. Of the two layers

the external longitudinal by contraction shortens the tube and makes

it rigid while the internal circular by a wave of contraction from

above downward propels the contents toward the lower end of the

tube. In the cardiac stomach the internal oblique layer of muscle

is composed of a few radiating strands over the fundus, the effect

of which is not important. The layers of muscles are joined to-

gether by a thin connective tissue which carries small blood and

TUBE PLAN OF STRUCTURE OF ANIMAL BODY 67

SI cssesis-cmsd:< Glazun of aerves called the plexus of Avcsbech.

In the pyloric end of the stomach the internal circular layer is thick-

ened to form the sphincter pylori. The character of the contents

of a tube governs the amount of muscle which it contains and when

the contents consist of a small amount of liquid, ciliary motion is

_ Sufficient. The contents of the four-coated tube are large. There

_ is no force behind them and therefore a well-developed muscular

apparatus must be provided in order to move the contents from one

end of it to the other.

«3 - Subepithelial coat—This is composed of areolar tissue which

joins the muscular and epithelial coats and contains blood vessels,

____ lymphatics, a plexus of nerves called the plexus of Meissner, and in

_ two places, vis., oesophagus and duodenum, secreting glands.

While this coat unites the epithelial and muscular coats it allows

____ freedom of motion of the former upon the latter on account of its

areolar character. It is widest in the stomach and the epithelial coat

____ is moresfreely movable than in other parts. It contains parts of

_____ Peyer’s patches which are confined to the lower portion of the small

____ imtestine and which extend into the epithelial coat.

_ 4 Epithelial coat-—This coat is also called mucous membrane or

mucosa. The term epithelial coat is preferred because it does not

____ dead one to think that its chief function is mucin producing, but may

___ be any secreting function. It is made up of a muscularis mucosae

which is composed of two very thin layers, an external longitudinal

OP ay

*..

——

____ and internal circular, of smooth muscle, and of a connective tissue

____ base, containing in some places diffuse masses of lymphoid tissue, as

___ in the stomach, in others, as small and large intestines, solitary glands

__ and parts of Peyer's patches, blood and lymph vessels. Resting upon

___ the latter is a stratified pavement epithelium as in the oesophagus, or

____ embedded within it gastric glands as in the stomach, crypts of

__ Lieberkiihn and villi as in the small intestine, crypts of Lieberkiihn

____ with many goblet cells as in the large intestine, and lymphoid tissue in

which are incomplete crypts as in the vermiform appendix. The

__—s muscularis mucosae distinguishes this type of tube from all others.

In the examination of a section if we find it we know we are exam-

__ ining a four-coated tube and that this belongs only to the alimentary

canal.

ss" The muscularis mucosae is required in this tube for the proper

adjustment of the epithelial structure to the moving contents and for

68 J. S. FOOTE

the purpose of shortening the villi of the small intestine, as a result

of which the contents of the central lacteals are set in motion. There

is perhaps no other tube in which the adaptive function of the mus-

cularis mucosae would be of any advantage to the tube because there

is no other tube having the same character of contents. If there

was no muscularis mucosae in the alimentary canal the epithelial lin-

ing would be pouched by the driving force of the muscular coat and

having no means of withdrawing itself would be torn.

The four-coated tube then is a motor tube adapted to the pro-

gressive motion of its contents and also to the application of its epi-

thelial lining to the contents. The various organs which belong to

this tube together with their structures are given in the following

outlines. (Table A.)

CONSTRUCTIVE METHOD

Since so many of the organs of the body are tubes and the walls

of the tubes are composed of coats and layers, a constructive method

of learning these structures may be employed. The various coats

and layers are all drawn on the same curve, printed and cut out of

suitable material. By placing these parts together according to the

arrangements in the outlines the different organs of the tube forma-

tion may be constructed. It is believed that the actual construction

of an organ by means of its parts fixes it in the mind as a reality.

The simple matter of handling the coats and layers and placing them

in the positions which they naturally occupy discloses a plan of struc-

ture and furnishes a reason for many of their actions.

Thus, referring to Plate IX, if we take 14, 11, 8, 4, 6, 9 and Io,

and arrange them according to the outline of a four-coated tube we

shall have the pyloric end of the stomach. (See Plate XIV, fig. 1.)

In a similar manner any tube may be constructed. The numbers

at the ends of the coats in the plates are for convenience in the illus-

tration of the method and the order is not significant; thus fig. 11

indicates the external longitudinal smooth muscle. The fine details

of structure are to be worked out in the laboratory. The object of

this method is to give as much prominence to the plan of formation

as to the tissues and cells, and this can be accomplished better by

the building process than by any other. Connective tissue, smooth

muscle, epithelium, blood vessels, nerves, and lymphatics do not make

a stomach unless they are arranged according to a definite design,

BOINeal fcenssas thar i, Gas ‘cornective fans coat, sexe

_ muscle, muscularis mucosae, and subepithelial coats may be used to

_ build up any tube containing these parts. The teacher will call

_ attention to variations. After constructing the tubes according to

_ the outlines the microscopical section is examined in detail. The

outlines give a word picture of the structure, the models the design

_ of the structure, and the microscopic section the real structure.

_ From the structure and function of the four-coated tube it is evi-

_ dent that some variation in structure will be necessary in order to

MM Gerciore the adaptation ot the epcieial ning, would not be

f Orner Tupe Classes

SIN Sinibulests maceses i talcen from the four-conted tutie itiere

__ is nothing to separate the epithelial coat from the sub-epithelial and

hence the epithelial coat with the connective tissue coat underneath

cs cuted tube ta tow This makes a three-coated tube. It

is a three-coated tube in function as well as structure. It is still a

motor tube and has two sets of motor apparatus, vis., smooth muscu-

_ lar coat and cilia. The muscular coat may have one, two, or three

“hag The uterus, vas deferens, lower ureter, and bladder have

py Saree layers; the Fallopian tube, vagina, epididymis, seminal vesicle,

_ upper ureter, and any large duct, have two layers; the artery, vein,

and large lymphatic, one. The larger blood vessels do not have the

| definite coated arrangement, but have smooth muscle and clastic tis-

gue intermixed. The Fallopian tube, uterus, epididymis, vas deferens,

| ‘and bronchus have cilia and hence are provided with the two set of

_ motor apparatus. The presence of a muscular coat in the walls of

_ these tubes shows that their contents are continually or intermittently

in motion and tat consdrable fore maybe required to move the

contents. The presence of a ciliated lining in some of them shows

that the contents may be very small and very little force is required to

move them. The presence of both muscle and cilia shows that the

contents may be large and moved with difficulty, or small and easily

moved. The circulatory tubes differ from other tubes in this re-

ae 6 i

aoe

nia

7° J. S. FOOTE

spect—that their contents are propelled by a force from behind and

hence the muscular coat arrangement is not necessary. In none of

these tubes would a muscularis mucosae be of any use. In the blood

vessels and bladder a hydrostatic pressure exerted in all directions

would not demand local adaptation of the enclosing surface. In the

genital and respiratory tubes, epithelial adaptation to contents at or-

dinary times would do nothing and at the times when the muscular

coat was at work could accomplish nothing. The epithelial coat has

a connective tissue foundation and carries blood vessels, nerves, and

lymphatics ; but in no case, secreting glands. The epithelium varies

according to the location of the tube. Nearly all varieties are found.

The outside connective-tissue coat may contain plates of hyaline car-

tilage and secreting glands as in the bronchi. Here open tubes are

required. The systems and organs which belong to the three-coated

tube may be found in the following outline: (See Table B.)

The eye is a modified adaptation of the three-coated tube. Its

diameters are nearly equal as the organ is nearly spherical. It is

a combination of the segments of two spheres of different curva-

tures. It is not a motor tube and therefore has no regular muscular

coat. However the three-coated tube arrangement is still preserved,

as appears in the table following. (Table C, upper part.)

Plate X represents the structures in the outline of a three-coated

tube. These organs may be built up by using the coats and layers

of both plates. For example, place in order of outlines, Pl. IX,

figs. 14, 11, 8; Pl. XI, figs. 25, 31, and the organ will be the

epididymis. (See fig. 2, Pl. XIV.)

This completes the muscular tubes. If all the muscular layers be

taken from the three-coated tube there will remain the epithelial and

connective tissue coats. If C-shaped rings of hyaline cartilage are

introduced into the connective tissue coat which also contains secret-

ing glands, a two-coated tube will be formed. To this class belong

the trachea and large bronchi, as is seen in the outline which fol-

lows. (Table C, lower part.) 4

These organs may be built up as follows: PI. X, fig. 15, and Pl. —

XI, figs. 33 and 27. (See fig. 3, Pl. XIV.) The essential require- >

ments of this class of tubes are that it be constantly kept open,

and that the very small liquid contents be moved toward the upper

end. The first requirement is made possible by cartilaginous rings,

the second by the ciliated epithelial lining. Between the ends of the

TUBE PLAN OF STRUCTURE OF ANIMAL BODY 71

I stnesc very little excoth muscle is Sound arrenged in lon-

fs — and transverse layers. This muscle however evidently

kes no part in the propulsion of the contents. If the cartilage is

taken from the two-coated tube a single coat of two layers will re-

SEE ne? Do desicneted 2s = ono-conted tube This tube is

omposed of an epithelial layer on a basement membrane or upon a

eal comnective tissue containing blood vessels, nerves, and lym-

_ phatics, with or without secreting glands. These tubes are generally

_ small and constitute the structural units of many organs. They may

__ be united by connective tissue and form organs such as the kidney,

_ testicle, ovary, secreting glands, lung, or may be in large expanded

eas as in the skin and serous membranes, or may be in the form

a tube enclosed in a bony canal as in the ear. They

rm the tubuli seminiferi, Graafian follicle, tubuli uriniferi, capsule

of Bowman, alveoli of lungs, acini of secreting glands, small ducts,

skin, hair follicle, serous membranes, and vestibule, utriculus, sac-

culus, semi-circular canals, and cochlea of the ear. The ear may be

considered a coiled tube mostly enclosed in bone. This type of tube

_ is adapted by structure to the function of secretion and special sense.

___ Seereting glands are all constructed upon the same plan, viz: a base-

___ ment membrane with the circulation on one side of it, and epithelium

on the other. This brings the epithelium as near as possible to the

blood, a condition of structure absolutely essential for the act of se-

cretion. A structureless basement membrane represents the smallest

‘supporting structure which can be placed between a cell and its blood

_ supply. What is true in regard to glandular structure is also true

: re structures of special nenes. It is as essential that neuro-

Be should be close to the blood stream as it is that secreting

P should be. All highly organized cells require such posi-

tions. The various organs which belong to this tube are given in

the following outline : (See Table D.)

Place in the order of the outline of a one-coated tube, Pl. XI, fig.

_ 33, and Pi. XIII, fig. 60, and the organ will be a secreting gland

Ge Pt XIV, fig. 4). If the basement membrane and connective

_ tissue are taken from the single-coated tube, the epithelium remains

and this is always simple pavement and forms the single layer class

BF of tube. It is the simplest tube in the body and to it belong the

blood and lymph capillaries. It is composed of one layer of pave-

"ment epithelial cells which are united by cement (see Pl. XIV, fig.

—_-

§).

72 J. S. FOOTE

This is the thinnest structure which can be placed between two

liquids and hence is best adapted to osmotic conditions and the proc-

esses of cell nutrition. (See outline which follows. Table D, latter

part.) Looking over these five classes of tubes it may be seen that

structurally

A four-coated tube minus a muscularis mucosae is a three-coated

tube.

A three-coated tube minus its muscular coat and plus cartilage

rings is a two-coated tube.

A two-coated tube minus its cartilage is a one-coated tube.

A one-coated tube minus its basement structures is a one-layer

“tube ; that is, the muscularis mucosae, muscular coat, cartilage rings,

and basement structures are the differentiating structures in the

walls of tubes. There still remain certain parts of the body which

apparently, at least, do not conform to the tube plan of structure.

These parts are the nervous system, thymus, spleen, lymph nodes,

‘and adrenals.

“In the development of the cerebro-spinal system the rudimentary

part is formed from the thickened medullary parts of the involuted

-epiblast, the ridges of which rising from the surface of the epiblast,

-are united dorsally along the middle line so as to form a hollow

medullary tube. This tube is wider at its anterior or cephalic ex-

tremity and this dilated portion is divided by partial constrictions

into three primary cerebral vesicles which represent the anterior,

middle, and posterior divisions of the brain. The spinal portion re-

‘tains a more uniform cylindrical shape. The continuous cavity en-

closed within the primitive medullary tube is the same with that

which constitutes the central ventricles of the brain and central canal

of the spinal cord.” (Quain’s Anatomy.) Thus the brain during

its early existence is the dilated anterior portion of the primary

medullated tube derived from an indentation of the epiblast and the

spinal cord is the remainder of that tube. In the adult the central

ventricles of the brain and canal of the spinal cord still remain,

showing that a tube plan is the plan of formation, although many

structural additions and modifications have been made. The ven-

“tricles and central canal are lined with simple ciliated epithelium

(fifth ventricle lined with simple pavement). Structurally then the

“brain and cord are covered on the outside by a connective tissue layer

(pia mater) and are lined with a simple epithelium like certain other

ae ee ee

TUBE PLAN OF STRUCTURE OF ANIMAL BODY 73°

’ a. Functionally the tubular character is not so clearly marked.

= A central canal is essential to the volumetric increase’

. and decrease of these organs ; so that, although the functions of these

remaining parts are reduced to blood cells. Its trabeculae of smooth’

_ muscle suggest a relationship of force pump to the liver and the

spleen would belong to the three-coated tubes.

The lymph nodes are composed of masses of lymphoid tissue

= surface of the capsule and outer surface of the trabeculae; so»

_ that the channels are widened parts of the lymph vessels within the

_ modes. This places them under the one-layer tubes. As far as func-

_ tion is concerned the parts outside of the channels are reduced to the

; "functions of lymphoid tissue or leucocytes.

‘The adrenals are composed of cells arranged in different ways

7 ) ‘according to the zones which characterize the structure. A tube plan

_ is not sufficiently apparent in these organs to place them under a tube:

74 J. S. FOOTE

CONCLUSIONS

That 8 proper conception ps eae ee

sion of an organ.

That design is as important as tissue or cell.

That most of the organs of the body can be arranged under five

tube classes, vis.: four-coated, three-coated, two-coated, single-

coated, and one-layer tubes.

That four-coated tubes are adapted to the progressive motion of

their contents and to the application of their epithelial structures to

the contents.

That three-coated tubes are adapted to the progressive motion of

their contents when necessary.

That two-coated tubes are adapted to conditions which require

open tubes.

That single-coated tubes are adapted to functions of secretion and

special sense,

That one-layer tubes are adapted to osmotic conditions.

That these tubes can be constructed by models and the constructive

process is a great help to the beginner.

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TUBE PLAN OF STRUCTURE OF ANIMAL. BODY 77

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tissue, | Connective tissue

or serous coat

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tissue | 1.

cellular

thick, blood

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TUBE PLAN OF STRUCTURE OF ANIMAL BODY 81

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TUBE PLAN OF STRUCTURE OF ANIMAL BODY

Nasal Mucosa

b. Basement Connective tissue

One-coated Tube

( Comtinued )

Tube

86 J. S. FOOTE

EXPLANATION OF PLATES

The plates are, to a certain extent, diagrammatic, for the sake of clearness

in demonstration. It is not the purpose of this system to exhibit accuracy of

structural details; but to present a constructive plan of visceral formation.

Plates IX—XIII inclusive, represent different tissues arranged in the form

of layers drawn as far as possible from a general formula, with which the or-

gans of the animal body may be constructed. The sole object is to make es-

pecially prominent the plan of structure. Plate XIV shows the five tube

classes built up according to this system. The system is devised as a teaching

method for beginners in histology.

Plate IX

Fig. 1. Epithelium of straight tubes of kidney.

Fig. 2. Internal longitudinal layer of smooth muscle.

Fig. 3. Internal oblique layer of smooth muscle.

Fig. 4. Circular smooth muscle.

Fig. 5. Subepithelial layer with Peyer’s patches.

Fig. 6. Subepithelial layer—general.

Fig. 7. Basement membrane, structureless.

Fig. 8. Internal circular smooth muscle layer.

Fig. 9. Muscularis mucosae.

Fig. 10. Epithelial layer of pyloric stomach.

Fig. 11. External longitudinal cross section of smooth muscle.

Fig. 12. Internal circular striped (voluntary) muscle.

Fig. 13. External longitudinal striped (voluntary) muscle, cross ‘Section.

Fig. 14. Connective tissue.

Plate X

Fig. 15. Connective tissue enclosing C-shaped rings of hyaline cartilage

and secreting glands.

Fig. 16. Connective tissue enclosing plates of hyaline cartilage and secret-

ing glands.

Fig. 17. Epithelial and lymphoid layer of the vermiform appendix.

Fig. 18. Villi.

Fig. 19. Crypts of Lieberkiihn.

Fig. 20. Epithelial layer of cardiac stomach.

Fig. 21. Stratified pavement epithelium of oesophagus.

Fig. 22. Subepithelial layer of duodenum.

Fig. 23. Subepithelial layer of oesophagus.

Fig. 24. Middle circular, vascular layer of smooth muscle.

PLATE IX

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BR Huu HAUTE #

THE CLASSIFICATION OF PROTOPHYTA

| Esceuoinc 4 Revision oF tHe FAMILIES, aND A REARRANGEMENT

a - or THE NortH AmeriIcAN GENERA

By CHARLES E BESSEY

a Tiiitiat stadice of the structure of the cell of the protophytes by

_ Professor Kohl of Marburg* have given additional interest to this

_ group of primitive plants. He has shown that instead of being com-

posed of non-nucleated cells, they possess primitive nuclei, which

_ develop simple karyokinetic figures during division. The nucleus is

not surrounded by a nuclear membrane, and is thus not sharply set

_ off from the surrounding cytoplasm. In the living cell its periphery

_ is extended into many pseudopod-like protrusions which penetrate

the cytoplasm, even reaching the cell wall at times. Kohl finds

_ genuine chloroplasts imbedded in the usually bluish or brownish

For many years I have been giving such attention to the general

_ classification of the protophytes as the time at my disposal would

The recent revival of interest in the blue-green algae has suggested

_ tome that it might be helpful to other students of these simple plants

_ to have these results before them. The manuscript is now printed in

__ssentially its original form. In it I have attempted to make such an

of the families and genera as would conform to my

ideas of their probable evolution

i I regard the group as consisting of autonomous plants, and while

“there may be a few which are merely forms or stages of other plants,

_ Tam convinced that the number of such is small, and further that in

all such cases they are still protophytes. The protophyte cell is quite

_ too characteristic to be mistaken for anything else, and we may rest

_ assured that none of these plants are earlier stages of any of the

i eellpareirndyeppaeteen

TUeber die Organisation und Physiologie der Cyanophyceenzelle und die mitot-

| tsche Teilung ihres Kernes, von Dr. F. G. Kohl, Professor der Botanik an der

Le it Marburg. Mit 10 lithographischen Tafeln. Verlag von Gustav Fischer

pie Jens. 1903. +

go CHARLES E. BESSEY

It will be observed that in the arrangement of the protophytic

genera I have not separated the colorless ones from those which

possess chlorophyll. In other words the “ bacteria” are here re-

garded as merely degraded (and therefore colorless) forms of the

protophyte type. In the Family Chroococcaceae there is one genus

of such colorless plants (“ bacteria”), viz.: Sarcina, whose relation-

ship to Merismopedia is evident. In the Oscillariaceae no less than

ten of the twenty-two genera are composed of colorless plants.

BRANCH I—PROTOPHYTA

Protophytes; Water Slimes

Single cells or threads of cells; reproducing by fission and endo-

spores. Plants minute, aquatic and normally blue-green, brownish

green or fuliginous, and generally surrounded by gelatinous matter.

Each cell contains a primitive nucleus not surrounded by a nuclear

membrane, so that it is not well defined.

Crass 1. SCHIZOPHYCEAE

Fission Algae

With the characters of the branch. About 1,000 species are known.

Key to THe Orpers.

Plants strictly one-celled, 1. Cystiphorae.

Plants few- to many-celled, forming threads, 2. Nematogeneae.

Order 1. CYSTIPHORAE

One-celled Protophytes

Plants one-celled, single or associated in loose groups in a gelatin-

ous matrix. There is but one family.

Family 1. CHROOCOCCACEAE

Blue-green Slimes

Microscopic plants with the characters of the order.

THE CLASSIFICATION OF PROTOPHYTA gt

thin, Chroococcus.

thick, lamellated, 2. Gloeocapsa.

‘alls confluent in colonies,

Colonies forming a stratum, 3. Aphanocapse.

Colonies globular, solid,

1. Single, envelope thin, 4. Microcystis.

2. Aggregated, envelope thin, 5. Polycystis.

3. Single, envelope thick, 6. Anacystis.

4. Cells cuneate, 7. Gomphosphaeria.

c. Colonies globular, hollow, 8. Coelosphaerium.

d. Colonies irregular, latticed, 9. Clathrocystis.

dividing regularly in two or three planes,

green, 10. Merismopedia.

Plants colorless (bacteria), 11. Carcina.

cylindrical, dividing in one plane only,

A. Ceti Division Irrecutarty 1n Turee PLANEs.

I. Chroococcus Naegeli. Cells globose, with thin walls, solitary

____ or in small groups, blue-green, yellow, or reddish——-On damp rocks,

___walls and earth, and in ponds and springs. Diameter of cells 3

— to 25h.

} 2. Gloeocapsa Kuetzing. Cells globose, ‘with thick and lamellated

walls, solitary or in small colonies surrounded by the walls of the

mother-cells, blue-green, lead-colored, yellowish, or reddish_—On wet

___ rocks, walls, and earth. Diameter of cells, cytoplasm 2.5 to 6 »—

____ including walls, 3 to 10 or 15 or more.

_—s- 3 Aphanocapsa Naegeli. Cells globose, with thick, soft, colorless

'_ __-walls confluent into a gelatinous stratum in which are imbedded the

____ blue-green cytoplasms.—On wet rocks, walls, and earth, and in ponds

and streams. Diameter of cells, cytoplasm 2 to 8», usually 3-5 ».

4 Microcystis Kuetzing. Cells globose, minute with thin walls,

densely aggregated into solid spherical colonies, each enclosed in a

close thin envelope, blue-green, yellow, or orange—On moist sur-

faces of wood, bark, earth, etc. Diameter of cells 1.5 to 4»; colonies

20 to Gon.

5. Polycystis Kuetzing. Cells globose, minute, with thin walls,

densely aggregated into solid spherical colonies (as in Microcystis)

___ of which several are enclosed in a thin envelope, blue-green, yellow,

a ~ iil ie ee

‘ —— Te “3

ie eae eS yee '

‘aie a saa

ry a

92 CHARLES E, BESSEY

or orange.—On moist surfaces and in pools. Diameter of cells 2 to

3; colonies 50 to 100,.

6. Anacystis Meneghini. Cells globose, minute, with thin walls,

densely aggregated into solid spherical colonies, each enclosed in a

thickish envelope, pale blue-green, or brownish.—In springs and

ponds. Diameter of cells 1 to 4; colonies from 4 to 10m, to 150

to 300 mw.

7. Gomphosphaeria Kuetzing. Cells cuneate, in small colonies

which are aggregated into solid spherical compound colonies with

thickish envelopes, blue-green, yellow, or orange.—In pools and

ditches. Diameter of cells about 4; colonies 10 to 25, or even

50 to 75».

8. Coelosphaerium Naegeli. Cells globose, in small colonies,

which are aggregated into compound globular, hollow colonies, the

walls of the small colonies soon confluent and disappearing, blue-

green and granulose—In ponds. Diameter of cells 2 to 5; of

colonies 40 to 100 p.

g. Clathrocystis Henfrey. Cells globose, aggregated into minute,

gelatinous, irregular saccate or latticed colonies, blue-green.—Float-

ing on ponds and pools. Diameter of cells about 3; colonies 25

to 1204p.

B. Ceci Division REGULARLY IN Two or THREE PLANES.

10. Merismopedia Meyer. Cells globose with thickish confluent

walls, aggregated in flat, quadrate colonies of 4, 8, 16, 32, 64, etc.,

blue-green.—Floating in ponds. Diameter of cells 3 to 4.5

11. Sarcina Goodsir. Cells globose or at first angled, with thin

walls, confluent in flat (or cubical) colonies of 4, 8, 16, 32, 64, etc. ;

colorless.—In intestinal or other animal fluids, and in stagnant pools.

Diameter of cells 1 to 2, rarely 3 to 4p.

C. Ceti Division 1n ONE PLANE ONLY.

11. Synechococcus Naegeli. Cells cylindrical, or oblong, with

thin walls, solitary or in small groups, blue-green, or sometimes yel-

lowish or orange.—On wet rocks and in pools. Diameter of cells

7 to 16.

12. Gloeothece Naegeli. Cells cylindrical or oblong, with thick

colorless lamellated walls, often forming colonies enclosed within a

common wall, blue-green, lead colored, yellowish, or reddish—On

wet rocks, earth and in pools. Diameter of cells 1.5 to 2.5 in our

species, much larger or smaller in others.

THE CLASSIFICATION OF PROTOPHYTA 93

. Aphanothece Naegeli. Cells cylindrical, with the walls gela-

and confluent into a continuous roundish mass in which the

Order 2. NEMATOGENEAE

Filamentous Protophytes

cngdipboear depend dkam moth gendpeherticrr

an outer continuous layer as a sheath which encloses the

cylindrical, motile, 2. Oscillariaceae.

Cells differentiated, heterocysts present,

of cells in one plane only,

moniliform, unbranched, 3. Nostocaceae.

i Ais of alla siilematy.in tiene ghanen,

Threads with true branches, 6. Sirosiphoniaceae.

"The following scheme illustrates the relationship of the families:

By i

94 CHARLES E. BESSEY

threads are imbedded (zoogloea). Reproduction by hormogones, i. ¢.,

by the separation of few-celled sections of the threads, which after-

wards increase in length by fission of their cells. Under favorable

conditions the threads are motile, moving alternately forward and

backward, at the same time curving and rotating.

Key ro true GENERA.

A. Tribe Microcoleae. Cells colored, green or greenish: usually two or more

threads in each sheath.

I. Threads not very numerous in each sheath,

a. Sheaths firm, lamellose; threads not capitate,

1. Sheaths hyaline or colored, containing two or more threads,

1. Schisothrix.

2. Sheaths purple or salmon colored, containing one thread,

2. Porphyrosiphon.

b. Sheaths soft and more or less diffiuent,

1. Sheaths hyaline, containing several capitate threads, cells short,

3. Hydrocolewm,

2. Sheaths hyaline or dark yellowish, containing few, remote, not

capitate threads; cells longer than broad, 4. Dasygleea.

II. Threads many, crowded in each hyaline sheath,

Sheaths not lamellose, more or less mucose, 5. Microcoleus.

B. Tribe Lyngbyae. Cells colored, green or greenish; threads solitary in the

sheaths, or sheathless,

I. Threads spuriously branched, or simple, apex always straight, sheaths firm,

a. Threads spuriously branched,

1. Threads free, branches often in pairs, 6. Plectonema.

2. Threads in fascicles, branches single, 7. Symploca.

b. Threads unbranched, free, 8. Lyngbya.

II. Threads simple, apex sometimes curved, sheaths thin, mucose, hyaline,

or apparently wanting,

a. Sheaths diffluent, threads straight, 9. Phormidium.

b. Sheaths apparently wanting in most cases,

1. Threads straight or slightly curved, 10. Oscillaria.

2. Threads spirally curved,

a. Cells evident, 11. Arthrospira.

b. Cells not evident, 12. Spirulina.

C. Tribe Leptotrichiae. Cells colorless. Threads without sheaths or nearly so,

I. Normally filamentous,

a. Threads with sheaths, 13. Leptotrichia.

b. Threads without sheaths, 14. Begiatoa.

Il. Normally in short rods, sheathless and free (not aggregated as in III),

a. Spores internal (endosporous),

1, Cells straight or slightly curved,

a. Spores smaller than the diameter of ordinary cells,

i. Spores forming in ordinary cells,

THE CLASSIFICATION OF PROTOPHYTA 95

(e) Cells with uniform protoplasm, 15. Bacillus.

(>) Cells with polar-diblastic protoplasm,

16. Pasteurella.

ii. Spores formed in special, swollen cells, 17. Clostridium.

i. Spores in normal cells swollen in the middle, 18. Cornilia.

ii. Spores in special clavate cells, 19. Vibrio

2. Cells spirally bent, 20. Spirilium.

b. Spores formed by the fission of cells (arthrosporous),

1. Cells cylindrical, straight, or curved, a1. Pacinia.

2. Cells ellipsoid, straight, 22. Bacterium.

IIL. Rods aggregated in plasmodium-like bodies,

a. Rods straight,

1. Forming external cysts, 23. Chondromyces.

2. Forming internal cysts, 24. Polyangium.

b. Rods curved. 25. Myxococcus.

Tribe I. Microcoreae. Cells colored, green or greenish ; usually

two or more threads in each sheath.

1. Schisothrix Kuetzing. Sheaths firm, lamellose, hyaline, dark

yellowish, or purplish, occasionally pale blue, containing a few loosely

aggregated threads; cells often longer than broad, never much

shorter, end cell straight, often attenuated, neither thick-walled nor

capitate.—In water or moist places. Threads small, 1 to 3», rarely

more than 5 » in diameter.

: 2. Porphyrosiphon Kuetzing. Sheaths firm, lamellose, purple or

___ salmon colored, containing but one thread ; cells as long as or shorter

than broad, end cell obtuse, neither thick-walled nor capitate—On

moist earth. Threads rather large, 10 or more in diameter.

3- Hydrocoleum Kuetzing. Sheaths more or less mucose, or sub-

amorphous, in age diffluent, sub-lamellose, hyaline, containing sev-

eral threads; cells shorter than broad, end cell straight, more or less

_ attenuated, capitate, its terminal wall thickened.—Aquatic, mostly

marine plants. Threads rather large, usually more than 10, in

diameter.

4. Dasygloea Thwaites. Sheaths mucose, diffluent, very much

enlarged, hyaline or dark yellowish, containing a few remote threads,

cells as long as or longer than broad, end cells straight, truncate.

conical, neither thick-walled nor capitate—In marshes. Threads

rather small, 4 to 6m in diameter.

5. Microcoleus Demazieres. Sheaths more or less mucose, in

some species eventually diffluent, not lamellose, hyaline, crowded

96 CHARLES E. BESSEY

with many threads; cells not much longer than broad, end cell usu-

ally straight and attenuated (in one species capitate) —In water or

on moist earth. Threads usually 4 to 10, in diameter, in some

species less.

Tribe II. Lyncpyae. Cells colored, green or greenish; threads

solitary in the sheaths, or sheathless.

6. Plectonema Thuret. Sheaths firm, hyaline, rarely golden yel-

low; threads spuriously branched, singly or in pairs; cells mostly

shorter than broad, end cell straight, rarely attenuated, not capitate.

—Plants consisting of free threads growing on sticks and stones in

ponds and streams. Threads in different species from I or 2, to

nearly 50 in diameter.

7. Symploca Kuetzing. Sheaths firm or sub-mucose, thin,

ies spuriously branched, singly; cells as long as, or longer than

broad (in one species shorter), end cell straight, often somewhat

attenuated, and sometimes with its walls slightly thickened—Aquatic

or terrestrial plants whose threads are usually collected in ascending

fascicles. Threads small, mostly less than 3 or 4, in diameter

(one species 6 to 14).

8. Lyngbya C. Agardh. Sheaths firm, thin or later thick and

lamellose, hyaline, rarely dark yellowish; threads unbranched; end

cells straight, slightly if at all attenuated, sometimes with a thicker

terminal wall (capitate).—Growing in salt, fresh, or thermal waters,

or on the moist earth or the surfaces of other plants. Threads com-

monly 5 to 8m or even 20 to 30 in diameter (in a few species less

than 2 pe).

9. Phormidium Kuetzing. Sheaths thin, mucose agglutinated,

partly or entirely diffluent, hyaline; threads unbranched, sometimes

moniliform; cells usually shorter than broad, end cell straight or

curved, usually attenuated, sometimes capitate-—Aquatic or terres-

trial plants. Threads usually about 3, or less in diameter, a few

10 to Ilp.

10. Oscillaria Vaucher. Sheaths very thin, or apparently want

ing in most cases; threads unbranched, cylindrical or mouililell

straight or slightly curved; end cell usually attenuated, straight or

curved, terminal wall often thickened.—Growing in water or in wet

places, forming dark green patches. Threads from very small (2

to 3 in diameter) to very large (50 to 60,4).

11. Arthrospira Stizenberger. Sheaths apparently wanting;

ee ee ae -)

THE CLASSIFICATION OF PROTOPHYTA 97

"threads unbranched coiled into a loose spiral; cells evident, end

_ cells rounded, not capitate.—Aquatic. Threads in our species 5 to

8p in diameter (a Brazilian species 2 to 3 »).

_-—s«&2. Spirulina Turpin. Sheaths apparently wanting; threads un-

branched, coiled into a close spiral; cells not evident—Aquatic.

Tribe III. Leprorricutar. Cells colorless, threads without

sheaths, or nearly so. (“ Bacteria.”) *

13. Leptotrichia Trevisan. Threads long, slender, indistinctly

septate, each enclosed in a thin sheath; usually not oscillating; not

eter of cells 1 to 4 or even 16 to 20.

15. Bacillus Cohn. Rods cylindrical or nearly so, straight or

_ and fluids of animals, a few saprophytes in water and decaying

_ fganic matter. Rods 0.5 to 0.7 » in diameter, and two to four times

as long.

a *The Myxobacteriaceac, which have been carefully studied by Dr. Roland

_ Thaxter (Botanical Gazette, 17: 389. 1892; 23: 395. 1897; 37: 405. 1904)

probably belong here. Their “rods” are evidently the same as the “rods” in

the organisms described under the Leptotrichiac. They form plasmodium-like

“ peeudofructifications.” The Myxobacteriaceac

modification of the usual aquatic bacterial type. It may

that they are xerophytic Leptotrichieae, while ordinary bacteria are

hydrophytic. They may be regarded as a sub-tribe, with the characters given by

Dr. Thaxter as in the text.

98 CHARLES E, BESSEY

17. Clostridium Prazmowski. Vegetative rods cylindrical or

ovoid, straight, or slightly curved, ends equal, rounded; cell proto-

plasm uniform; spores small, formed in special, swollen cells.—

Mostly saprophytes in decaying organic matter, a few parasites in

the fluids of animals. Rods 0.5 to 1» in diameter, and three to four

times as long.

18. Cornilia Trevisan. Rods cylindrical, straight, ends equal,

rounded or pointed; cell protoplasm uniform; spores large, formed

in ordinary cells which then become swollen centrally or apically —

Mostly saprophytes in decaying organic matter, a few parasites in

the fluids of animals. Rods 0.3 to I » in diameter.

19. Vibrio Zopf. Vegetative rods cylindrical, sometimes joined

into long threads slightly curved, or undulate-flexed, ends rounded,

sometimes flagellate ; spores large, formed in special, clavate-swollen

cells.—Parasites in the fluids of animals, and saprophytes in decay-

ing organic matter. Rods 0.5 to 0.8, in diameter, and from three

to ten times as long.

20. Spirillum Ehrenberg. Rods cylindrical, spirally curved, ends

sometimes flagellate; cell protoplasm uniform; spores small, formed

in ordinary cells—Saprophytes in decaying organic matter, and

parasites in the cells and fluids of animals. Rods 0.5 to 3 in diam-

eter, and of variable length, 5 to 10m, even to 100 or 2004.

21. Pacinia Trevisan. Rods cylindrical, straight or slightly

curved, often forming straight, curved, or undulate threads; cell

protoplasm uniform; spores formed by abstriction (arthrosporous).

—Mostly parasites in the cells and tissues of animals, a few sapro-

phytes in decaying organic matter. Rods 0.3 to I » in diameter, and

three to ten times as long.

. 22, Bacterium Ehrenberg. Rods short, ellipsoid, rarely cylin-

drical, straight, ends obtuse ; cell protoplasm uniform ; spores formed

by abstriction (arthrosporous).—Saprophytes in decaying organic

substances, rarely parasitic. Rods 0.5 to 2.5 » in diameter, and three

to four times as long.

Sub-tribe MyxopacrertAceagE. “ Motile, rod-like organism, mul-

tiplying by fission, secreting a gelatinous base, and forming pseudo-

plasmodium-like aggregations before passing into a more or less

highly developed cyst-producing resting state, in which the rods

may become encysted in groups without modification or may be

converted into spore masses.”—They are mostly saprophytes.

THE CLASSIFICATION OF PROTOPHYTA 99

The three genera at present recognized are characterized as

follows :

23. Chondromyces Berkeley and Curtis. “Rods forming free

cysts, in which they remain unmodified. Cysts various, sessile or

borne on a more or less highly developed cystophore.”—Eleven spe-

cies have been described as growing on rotten wood, dung, and

other organic matter.

24. Polyangium Link. “ Rods forming large rounded cysts, one

or more free within a gelatinous matrix raised above the substratum.”

—Six species, on wet wood, dung, etc.

25. Myxococcus Thaxter. “ Rods slender, curved, swarming to-

gether after a vegetative period to form definite, more or less en-

cysted sessile masses of coccus-like spores.”—Seven or eight species,

on decaying substances, dung, etc.

Family 3. Nostocaceae

Plants consisting of amber- or blue-green, more or less moniliform,

unbranched threads, composed of globose or sub-globose cells, spores,

and heterocysts; cell walls more or less transformed into mucilage

forming a gelatinous investing sheath, or by fusing, a structureless

jelly-mass in which the threads are imbedded. Reproduction in two

ways, (1) by free-swimming hormogones of a few cells (4 to 12)

which develop directly into new plants, or form rows of spores; (2)

by spores formed in ordinary threads as well as in hormogones, which

divide internally into minute chains of cells which are set free by

the rupture of the old cell wall. The heterocysts are rounded,

usually enlarged cells without granular contents, whose function is

unknown.

Key ro tue Gewena.

A. Heterocysts intercalated,

I. Threads moniliform (i. ¢., composed of rounded bead-like cells) globose

or irregular,

a. Flexuously curved, normally in gelatinous masses,

1. Colored (sometimes very slightly), t. Nostoc.

2. Colorless (bacteria),

«. Threads evident, 2. Leuconostoc.

b. Cells in botryoid masses, 3. Staphylococeus.

c. Cells solitary or in zooglocac, 4. Micrococcus.

b. Nearly straight,

1. Colored,

100 CHARLES E. BESSEY

a. Threads parallel, in a closed tube, 5. Wollea.

b. Threads free, or in gelatinous masses, 6. Anabaena,

2. Colorless (bacteria), 7. Streptococcus.

Il. Threads cylindrical, nearly straight,

a. Agglutinated in fascicles, 8. Aphanizomenon,

b. Each in a sheath, 9. Nodularia.

B. Heterocysts terminal, 10. Cylindrospermum,

1. Nostoc Vaucher. Threads mostly moniliform, flexuously

curved, with or without a distinct sheath; cells globose, cask-shaped,

or cylindrical; heterocysts intercalary (rarely terminal) ; spores in-

tercalary, spherical or oblong.—Forming globose, nodulose, or

irregular, amber- or pale-green gelatinous masses I mm. to 50 mm.

or 100 mm. in diameter, in water or on moist ground. Threads

small, 2 to 9 in diameter.

2. Leuconostoc Van Tieghem. Threads moniliform, curved, com-

posed of globose, colorless cells—Forming globose, nodulose, or

irregular, white, gelatinous masses on beet-root sugar and the vessels

used in its manufacture (also on leaves of plants, where they appear

to grow in the sweetish exudate). Cells 0.8 to 1.2m in diameter.

3. Staphylococcus Ogston. Globose cells single, in pairs, short

threads, or botryoid masses, colorless.—Parasites in the cells and

fluids of animals, and saprophytes in decaying organic matter. Cells

0.3 to 2 in diameter.

4. Micrococcus Cohn. Globose or ovoid cells single, in short

threads, or in irregular gelatinous masses (zoogloeae), colorless.—

Parasites in the cells and fluids of animals, and saprophytes in de-

caying organic matter. Cells 0.15 to I m, rarely 2 to 4 in diameter.

5. Wollea Bornet and Flahault. Threads blue-green, moniliform,

nearly straight, sheaths confluent; cells oblong; heterocysts inter-

calary; spores intercalary, oblong.—Forming erect or floating cylin-

drical gelatinous masses enclosing many parallel agglutinated threads,

in ponds. Threads small, 4 to 5 in diameter.

6. Anabaena Bory. Threads blue-green, moniliform, nearly

straight, without a sheath, or but a vestige of one; cells globose or

sub-globose ; heterocysts intercalary; spores intercalary, globose, or

elongated.—Floating free in ponds, or forming gelatinous masses

on moist surfaces. Threads mostly small, 4 to 6 in diameter (one

species 14»).

7. Streptococcus Bills. Threads moniliform, nearly straight, with-

out a sheath; cells globose, colorless.—Parasites in the cells and

THE CLASSIFICATION OF PROTOPHYTA ror

ids of animals, and in decaying organic matter. Cells 0.2 to 2»

9. Nodularia Martens. Threads blue-green, cylindrical, nearly

"straight, each usually enclosed in a sheath ; cells disk-shaped ; hetero-

_ cysts intercalary, compressed ; spores intercalary, globose.—Threads

4 to 18 » in diameter, floating free in ponds or forming an indefinite

nearly straight, without a sheath; cells cylindrical; heterocysts

_ terminal, globose or sub-globose ; spores contiguous to the hetero-

___ eysts, oblong or cylindrical—Forming an indefinite stratum in

___ ditches, on wet rocks, and on the ground. Threads small, 3 to 5 » in

diameter.

Family 4. ScyTONEMACEAE

itis cousleting of cylindrical, green or brown, usually branched

_ threads which are composed of more or less disk-shaped cells;

____ end cells thin walled, dividing repeatedly in one plane, and thus

___ increasing the length of the thread ; ie ary at amet age

Key to rue Gewrna.

A. Threads solitary in cach sheath,

1. Unbranched, 1. Microcheete

Il. With spurious branches usually in pairs, 2. Scytonema.

Ill. With spurious branches single,

a. Threads fragile, plants terrestrial, 3. Hassallia.

b. Threads flexible, plants aquatic, 4. Tolypothrix.

B. Threads generally 2 to 6 in each sheath, 5. Desmonema.

e 1. Microchaete Thuret. Threads unbranched, solitary in each

_ sheath ; heterocysts basal and intercalary—Minute plants of salt and

_ fresh waters, growing in clusters or tufts about 1 mm, long, each

"thread 5 to 9 in diameter.

“ 8

102 CHARLES E. BESSEY

2. Scytonema Agardh. Threads solitary in each sheath, spuri-

ously branched by the rupture of the sheath and the protrusion of one

or commonly two branches.—Aquatic or terrestrial plants composed

of usually large threads, often several millimeters long forming inter-

woven mats; threads from 7 to 45 » broad, commonly 12 to 20,4.

3. Hassallia Berkeley. Threads minute, fragile, solitary in each

sheath, spuriously branched by the rupture of the sheath and the

protrusion of a single branch; sheath thin, not mucilaginous—Form-

ing a green stratum on moist ground or stones. Threads I mm. or

less long, 5 to 10» (or even 15) broad.

4. Tolypothrix Kuetzing. Threads larger, flexible, solitary in

each sheath, spuriously branched by the rupture of the sheath and

the protrusion of a single branch; sheath thin——Forming tufts 10 to

30 mm. high on plants and stones, or floating freely, in fresh

waters. Threads 8 to 10, or even 15 to 18» broad.

5. Desmonema Berkeley and Thwaites. Threads usually 2 to 6

in each sheath, sub-dichotomously branched, a heterocyst at the

base of each spurious branch; sheath thin——Forming small, green

tufts 5 to 6 mm. high on stones, etc., in streams and other fresh

waters. Threads 9 to 10, or more in diameter.

Family 5. RIvULARIACEAE

Plants consisting of tapering, green or reddish, simple or spuri-

ously branched threads, composed of nearly cylindrical (slightly

tapering) cells; lower cells much larger and greener than the upper

which form a slender, hyaline hair; longitudinal walls partly trans-

fomed into mucilage, forming a gelatinous investing sheath. Re-

production by hormogones and spores formed in the thicker portion

of the thread. Heterocysts usually at the base of the threads.

Key to tHe GENERA.

A. Threads free, simple or spuriously dichotomo-corymbosely branched,

I. Threads simple, or spuriously branched, the branches distinct and free, -

1. Calothrix.

Il. Threads spuriously branched,

a. Branches several (2 to 6) in each sheath, 2. Dichothrix.

b. Branches very many (even to 100) in each sheath, 3. Polythrizx.

B. Threads grown into crustaceous, hemispherical or globose masses,

THE CLASSIFICATION OF PROTOPHYTA 103

a. Threads simple, crowded parallel in crustaceous masses, 4. /sactis.

b. Threads spuriously branched, crowded and radiating, forming a globose

or hemispherical mass,

1. No spores known, s. Rivularia.

a 2. Spores large, solitary, 6. Gloeotrichia.

IL. Heterocysts intercalary, 7. Brachytrichia,

1, Calothrix Agardh. Threads simple or spuriously branched,

__ the branches distinct and free ; sheaths cylindrical, enclosing a single

_ thread; heterocysts intercalary or basal, sometimes none.—Forming

4 _ minute tufts or cushions a millimeter or so high on stones and other

_ Objects in fresh and’ salt waters, and on moist earth. Threads from

th to 25 to broad.

a i 2. Dichothsis >. Zanardini. Threads spuriously dichotomous, 2 to

_ Forming minute tufts or cushions 1 to 20 mm. high on stones and

other objects in fresh and salt waters. Threads usually 10 to 124

PU trmeienes 25 1 50

3. Polythrix Zanardini. Threads spuriously dichotomous, very

_ many (even to 100) enclosed in a common sheath ; heterocysts basal

and intercalary—Forming tufts and cushions 10 to 30 mm. high on

4 Stones in salt waters (Key West). Threads 5 to 6» broad.

4 Isactis Thuret. Threads simple or rarely spuriously branched,

. erect and parallel ; sheaths hyaline or yellowish; heterocysts basal ;

spores unknown.—Marine plants whose crowded, parallel threads

ewes scnall, flattish, crustaceous masses. Threads 7 to 9m broad.

' §. Rivularia Roth. Threads spuriously branched, crowded and

| sadiating; sheaths narrow to broad, hyaline or colored ; heterocysts

- basal; spores unknown.—Forming small, globular or hemispherical

masses a millimeter or so in diameter, in salt or fresh waters.

Threads 2 to 14» broad.

6. Gloeotrichia J. Agardh. Threads spuriously branched, crowded

and radiating ; sheath enclosing the base of the thread, dissolving

above, hyaline or colored; heterocysts basal; spores present, above

: heterocysts ; hormogones serial and numerous.—Forming globose

br hemispherical masses, a millimeter or so in diameter (or 20 to 100

1.), in fresh or brackish waters. Threads 4 to 9m broad.

7. Brachytrichia Zanardini. Threads spuriously much branched,

paralle spemenely. curved sheaths at first distinct, finally deli-

ng; heterocysts intercalary—Forming solid, or eventually

104 CHARLES E. BESSEY

hollow, gelatinous masses, 6 to 60 mm. in extent, in which the threads

are enclosed. Threads 5 to 6m broad.

Family 6. SrRostIPHONIACEAE

Plants consisting of cylindrical or irregular, greenish, brown, or

blackish, sheathed and usually branched threads, at first consisting of

a single row, but later mostly of several rows of cells; end cells

usually dividing at first repeatedly in one plane only, and later in

more than one plane, some of the latter again dividing repeatedly in

one plane (parallel to the axis of the thread) thus originating

branches ; all walls of the cells more or less transformed into muci-

lage, the outer forming a gelatinous sheath for the thread, the inner

separating the protoplasts; heterocysts intercalary (rarely terminal

also). Reproduction by hormogones and spores, the latter formed

by the change of disk-like cells toward the end of a thread into

roundish resting spores, which germinate after a period of rest.

Key To THe GENERA.

A. Threads consisting of one row of cells, rarely of two rows, 1. Haplosiphon.

B. Threads commonly consisting of two or more rows of cells, 2. Stigonema.

1. Haplosiphon Naegeli. Threads creeping, consisting of one row

of cells, rarely of two rows; branches erect, parallel.—Aquatic, cespi-

tose-floccose, slender plants, forming green, blue-green, or at length

brown tufts which are floating or attached. Threads 6 to 24 » broad.

2. Stigonema Agardh. Threads commonly consisting of two or

more rows of cells; branches irregular, spreading.—Terrestrial or

aquatic, dark brown plants, forming expanded, slimy strata. Threads

7 to 10m, or even 45 to 90, broad.

RIVER POLLUTION AND PURIFICATION

, , Srupy or THE Errect or Cutcaco Sewace Upon tHe WATER

: Suppty or Sr. Louis

By T. J. BURRILL

Chicago River discharges into Lake Michigan through one

Ics css scan ab aly or dee Grecton of tee low wer olend

Under these conditions the stream—we can hardly say water—con-

_ sisted of a dark and seething mass of corruption, foul beyond the

iat words to destribe.

directly into the lake through pipes bearing no relation to the river.

The city water supply is from the lake and notwithstanding the

ntakes were pushed four miles from the shore the contaminations

0 often reach this distance. To prevent this and to purify the river

long been a problem of the utmost importance to the city and it

‘ha received the earnest attention of the authorities and the best

: of experts.

__ The Illinois and Michigan canal completed in 1848 connects with

he south branch of the river at a point within the city called Bridge-

‘por and at this place a lock and pumping works were established

to supply the canal when the water was otherwise too low for the

dats. The canal discharged in part at Lockport, 29 miles away, and

105

106 T. J. BURRILL

further at Joliet, 4 miles beyond, at both places into the Desplaines

River. At the latter point the canal crosses the river by means of a

dam and pool, so that the waters are well mixed, and continues

onward to LaSalle, where it opens into the Illinois River 95 miles

from Bridgeport.

At first the pumping at Bridgeport from the Chicago River was

only to supply the needs of navigation but as early as 1865 the city

arranged with the canal commissioners to utilize the pumps for

cleansing the river. From time to time other means have been

adopted for this purpose, but most reliance has been placed, espe-

cially of late, upon these pumps, by which the waters of the lake

were caused to flow in a slow current, at least part of the time,

through the river course into the canal and thus at length into the II-

linois River. This operation, gradually increasing in proportions, con-

tinued from the date mentioned onward through the remaining years

of the century, and at its close there was thus poured into the canal

about 35,000 cubic feet per minute of the river water and sewage,

of which the latter contributed an estimated amount of 26,000 cubic

feet... This sewage, including wastes from the stock yards, carried,

according to the same authority, the equivalent of 150 tons of dry

organic matter and ammoniacal salts daily into the canal. Still the

river was not cleansed and something more effectual became impera-

tive. The increase of pollution with little dilution made the effluent

stream more and more noxious to the inhabitants along its course

especially in its upper reaches and more and more contaminated the

city water supply. There was therefore a double reason for some

heroic action.

After wide examination of systems of sewage disposal in use, and

with much expert consultation, a bill was introduced in the state

legislature, which became in 1899 an Act creating the Chicago

Sanitary District and authorizing a sanitary canal through which

by gravity might pass 600,000 cubic feet per minute of water from

Lake Michigan into the Desplaines and hence onward down the IIli-

nois River. This canal begun in 1892 was completed sufficiently to

turn in the water on January 17, 1900, after an expenditure of over

$30,000,000. It connects with the south branch of the Chicago River

and discharges into the Desplaines at Lockport over a controllable

dam. It is 29 miles in length and runs somewhat parallel to the

* Long, Sanitary Investigations, Springfield, Ill., 1900, p. 37.

RIVER POLLUTION AND PURIFICATION 107

Illinois and Michigan canal, which remains as before. The flow

_ maintained during the first year (1900) varied from about 150 to

220 cubic feet per minute with some lower and some higher quanti-

ties. This is to be compared with 35,000 cubic feet previously

‘pumped. The reversed flow of the river through the city was made

in the interests of shipping not to exceed 3 miles an hour, but the

‘effect was speedily to change the black, maladorous cesspool into a

stream of blue water from the lake. The sanitary canal is an

immense relief to Chicago. What is its effect upon the valley of the

Illinois River and below ?

_ To make this more intelligible some description of the water

course onward is required. The Illinois River is formed by the junc-

tion of the Desplaines and Kankakee about 16 miles below Lockport

_ (12 miles southwest of Joliet). The Desplaines varies above Lock-

__ feet per minute at flood times, while the more stable Kankakee ranges

_ ¢ommonly from 30,000 to above 300,000. Further down stream the

main tributaries are the Fox, about two-thirds the size of the Kanka-

___ kee; the Vermilion, more like the Desplaines, sometimes practically

dry but subject to floods; Spoon River, most of the year a small

____ Stream, usually not above 5,000 to 10,000 cubic feet flow; and the

_ Sangamon, as large as the Kankakee. Besides these there are a large

number of smaller tributaries.

At Kampsville, 30 miles above the mouth of the Illinois where it

joins the Mississippi, the government maintains a dam and keeps a

record of the water. At one time in September, 1899, there was a

flow of only 10,000, but in June, 1902, there passed the station about

9,300,000 cubic feet per minute. These are extremes. Prior to the

Opening of the sanitary canal there was commonly a flow here from

‘March to June inclusive of about 1,000,000 to 3,000,000, and from

___ August to October, of about 250,000 to 500,000 cubic feet per minute,

‘ the latter not being more than the proposed flow of the sanitary

‘canal. Since the latter was opened the stream throughout has been

__- very noticeably greater than it was before during its lowest stages,

ee Se Its length from the

_ junction of its head waters to Grafton at its mouth is 263 miles.

| All the main tributary streams are strongly sewage-polluted and

_ there is a very extensive wash from a great area of highly fertile

r and well-populated regions, though with the exception to be noted

4 :

q 8

108 T. J. BURRILL

the amount of organic matter entering from any one point received

from other sources is small compared with that from Chicago. The

exception is in the case of Peoria and Pekin. Here, as is well

known, exist the largest distilleries and glucose factories in the coun-

try and great numbers of cattle are kept and fed upon the slops.

The direct wastes from the manufactories and all the offal from the

cattle sheds go directly into the river. This added to the sewage

of some 70,000 people makes the contamination of the stream at this

point only short of that from Chicago. Sometimes masses of filth

collect in the river to such an extent that in times of low water

dynamite has been used to break up the stranded islands composed

of it. We shall see below results of this pollution in the prodigious

multiplication of the number of bacteria in the water.

As related above, the sanitary canal was opened in January, 1900.

Anticipating this event the trustees of the Chicago drainage dis-

trict, acting upon the advice and cooperation of Arthur R. Reynolds,

M.D., Commissioner of Health of the City of Chicago, arranged in

1899 for an exhaustive chemical and bacteriological study of the

stream from Bridgeport to St. Louis. In order that this work might

have all possible weight and that the results might be abundantly

conclusive, Commissioner Reynolds was given authority to secure

under his own general direction prolonged series of independent ex-

aminations and analyses by several well-accredited experts. In the

fulfilment of this task the Commissioner arranged for the work by

the Municipal Laboratory of Chicago, by the laboratory of the Uni-

versity of Chicago, and by that of the University of Illinois. He en-

deavored also to secure the cooperation of Washington University or

of the City Laboratory of St. Louis, but in this was not successful.

The work as undertaken was put in charge of Dr. Adolph Gehrmann

of the laboratory first named, of Professor E. O. Jordan of the sec-

ond, of Professors A. W. Palmer and T. J. Burrill of the third. In

the latter case the bacteriological examinations were conducted by the

present writer and his results alone are herein given, except that

other general conclusions are mentioned. -

The work was commenced in May, 1899, and continued uninter-

ruptedly until October, r900. Further examinations, made during

the latter part of the year 1901, did not significantly modify the

earlier conclusions. Collections, usually one each week at each

place, were made from 38 carefully located stations on the course

RIVER POLLUTION AND PURIFICATION 109

i letesed aT Gibestarien, inclodiag the cansle' above named, the

__ Desplaines, Kankakee, Fox, Big Vermilion, Sangamon, Illinois, and

_ Mississippi rivers and from Chicago and St. Louis tap waters.

Comparative tests were also made of the Missouri River several miles

above its mouth. During the period mentioned there were received

by the writer and his assistants 2,800 samples, from which an aggre-

_ gate of about 30,000 bacterial cultures were made. In all this two

Seeeeeny ends were sought: (1) To determine for each sample the

_ number of bacteria in a cubic centimeter which could be made to

—, colonies on a culture plate, and (2) to test the presence or

absence in each sample of Bacillus coli-communis. In work of such

‘Magnitude, and upon waters generally so polluted, further refine-

= or not such pathogenic species as Bacillus typhosus were present in

___ the samples examined. In work of this kind it is impossible directly

_____ to identify the latter, but since the two species just named gain ac-

sess to such water from intestinal evacuations the presence of one

Of them must give a comparative indication of that of the other.

____ There is no room for doubt as to the polluted character of the head

__- waters of this stream. What becomes of the highly putrescible and

___ Often pathogenic germ-laden matter equal to 150 tons of dry matter

__ daily from Chicago and as much more from other sources that is

___ persistently poured into the water?

____The question has been much discussed and opinions have been

exceedingly diverse upon what has been called the self-purification

_ of running water. Somewhat misquoting an expression in a report

of a British commission, it has recently been asserted before the

American Medical Association that “ biologists have about come to

_ the conclusion that no river is long enough to purify itself.” Ina

_ fecent book on sanitation it is argued that the apparent purification

_ ima river course is principally due to the dilution by pure water and

not to any destruction of the organic matter with which the stream

is originally polluted. “ The theory of self-purification is now aban-

doned, or rather accepted only after so much modification that it is

ape lll

_ Because of contentions of this kind and otherwise the authorities

"of St. Louis, Missouri became alarmed lest the Chicago contamina-

4 Sedgwick : P Principles of Sanitary Science and the Public Health, p. 129.

IIo T. J. BURRILL

tions should reach the intake in the Mississippi River, from which

the city receives its water supply. An injunction has therefore been

sought from the United States Supreme Court against the use of the

sanitary canal, and the discharge into the Illinois River of Chicago

sewage. This suit is now in progress, Let us see what bearings

the investigations as summarized below have upon the problem.

It is not possible to give in detail the figures for all the results

of the cultures upon which this account is based. Neither does it

seem feasible within the limits of permissible space to describe meth-

ods of procedure. It should be said, however, that the greatest pos-

sible pains were taken to have the collections properly made and

shipped. The samples, taken in sterilized glass-stoppered bottles,

securely sealed and tagged, were packed in ice and commonly

reached the laboratory within eight to twenty-four hours after tak-

ing from the stream. After collectors and expressmen became ac-

customed to handling the packages, undue delay very seldom oc-

curred and only in rare cases was the packing ice completely melted

when the samples were received. Analyses were not made, or the

results were not included in the case of any samples not received in

good order. The collecting stations, so far as this account goes, are

named in the table, with the distance in each case from Chicago.

For the colony count standard plating agar was used at 1% acid

above the phenolphthalein neutral point and the plates were counted

after a uniform development period of 10 days at 20° C. For the

identification of Bacillus coli-communis carbolized lactose-litmus

broth with 1 cc. of water was first incubated at 38° C. for 48 hours,

and cultures indicating the presence of the bacillus were further con-

tinued for indol tests, glucose-fermentation tests, and milk coagula-

tion tests. No animals were inoculated.

NUMERICAL VARIATIONS IN DIFFERENT PARTS OF THE STREAM

A very casual inspection of the table will show the wide varia-

tions in the monthly average number of bacteria in a cubic centi-

meter of the waters examined—from a few hundred to several mil-

lions. At first sight there may not appear to be any law in these

differences, but further study will show that the numbers are always

very large at Joliet and that there is generally, and usually very

decidedly, a decrease to Averyville (North Peoria), then there is a

very great increase at Pekin, followed again by a gradual decrease

RIVER POLLUTION AND PURIFICATION Itt

~ to Grafton (mouth of the Illinois River). For the sake of brevity

____ the collections above Joliet are not given, but both in the Illinois and

_ Michigan and in the sanitary canals the numbers of bacteria found

were always represented by at least six and very often by seven

_ places of figures, the latter more commonly than the other for the

canal. The largest average number for any one month

_ during the whole work was from samples taken at Lockport, from

____ the Illinois and Michigan canal in July, 1899, and reached 5,323,750,

___ and the smallest from the stream anywhere from Bridgeport to St.

Louis was from samples taken from the Illinois River at Grafton in

October, 1899, namely 743. These, let it be noted, are each the

___—s averages of at least eight culture plates from four samples—weekly

collections, duplicate plates. The largest count from a single sam-

____ ple, during the whole course of the work, was made from the water

_____ at Lockport, April 17, 1900, and showed 11,200,000. The largest

monthly average from samples taken at Averyville (North Peoria),

__—s«:159 miles from Chicago, was 129,500 for February, 1900, while the

____ smailest was for June of the same year, viz., 1,637; but the preced-

img November there were practically the same number, 1,640. At

_ Grafton, 318 miles from Chicago and 143 from Pekin, the largest

. average was 191,500 from the Illinois for February, 1900, and 227,-

_-—s' Was, as above stated, 743 for October, 1899, and from the Missis-

__-‘Sippi 915 for July, 1899.

P A very similar showing, subject naturally to wider variations in

___ numbers, can be made by comparing the results of cultures from

____ Single samples taken on the same day (or at most not more than

_ «24 hours apart) from each of any two stations differently located in

__ regard to the principal source of pollution. In this way we may

compare the colony counts in cultures from Bridgeport and Avery-

, 159 miles apart, not by selecting maximum at one and mini-

m at the other, but just as they occur through given months.

they are for November, 1899, and April, 1900.

Nov. 7 Nov. ts Nov, o Nov. «7

Bridgeport 4,790,000 1,960,000 3,920,000 = 4,315,000

Averyville 550 1,100 1,200 2,800

April 5 April te April ry April 5

Bridgeport $300,000 «3,725,000 ‘11,200,000 «3,925,000

112 T. J. BURRILL

This is scarcely a fair showing for a general difference in the two

places, but it does illustrate excellently the marvellous decrease in

the number of bacteria that takes place in the running stream during

this distance of 159 miles. We shall see further along that there

is only one way by which this decrease can be explained.

As before mentioned, the river receives immense quantities of pol-

luting matter at Peoria and Pekin, and the number of bacteria very

soon correspondingly increase. Havana is only 25 miles below

Pekin and 37 miles below the main sewers of Peoria. There are

no tributary streams of importance between these places except

Mackinaw River, which carries a small volume of water drained from

a very rich agricultural region and subject to much pollution. It

enters a little distance south of Pekin. There is tabulated here the

results of all the examinations made in July, 1899, and in Septem-

ber, 1900, from Pekin and Havana.

July 7 July 13 July 20 July 26

Pekin 300,000 1,190,000 640,000 820,000

Havana 13,300 1,420 5,880 3,200

Sept. 6 Sept. 14 Sept. 20 Sept. 27

Pekin 1,320,000 600,000 47,500 2,280,000

Havana 35,500 4,150 144,000 19,000

These results show as clearly as figures can show anything that

there is some potent influence at work in cleansing the water. If

these numbers were specially selected from the very great variations

in the results as obtained, they would mean little or nothing, but an

inspection of the whole counts as put down in the laboratory records

shows that the lessons which may be drawn from such figures as

the above are abundantly supported and any one may construct other

comparisons from the monthly averages herewith presented, all

teaching the same thing. The differences as shown for Joliet, Mor-

ris, and Ottawa are commended to the reader especially interested.

There is practically no change in the volume of the water between

Morris and Ottawa, 24 miles, but the difference in bacterial content

is remarkable.

While with reference to particular counts there are many unex-

plained variations, the work in general very clearly and decidedly

shows that the numbers of bacteria at the polluted headwaters of

the stream are always very great, that these numbers more or less

constantly decrease to Averyville, then decidedly increase below

The Fox, Ottawa 11,027 5,475 84,166 2,962

The Sangamon, Chandlersville 7,125 3,683 105,875 4,450

The Mississippi, Grafton $,017 2,406 227,750 3,291

The Missouri, West Alton 16,325 179,750 12,450

The Illinois, Grafton 4155 743 159,500 2,708

This imi

stream from the place of pollution was equally evident before and

after of the Sanitary Canal. Any difference which the

reveal in regard to the results of 1899 and 1900

other

SEASONAL VARIATIONS

So much for the variations in the bacterial content of the waters

___ Of principal contamination. Note for instance the figures at Avery-

___ ville and Grafton. For easy comparison we may place together the

____ average results for February and August, 1900, from a number of

__ gtations on the Illinois River as follows:

” The sewage contaminations are undoubtedly as great in the summer

___ as in the winter. Are there other and added sources of bacteria in

cold weather, or do the organisms sooner die in warm water? It

114 T. J. BURRILL ’

has often been argued that the increase is prominently due to the

greater washing from the soil in times of floods and it cannot be

otherwise than that enormous numbers of bacteria do thus find their

way into the rivers with every cubic inch of fertile soil, but this does

not explain our tables of figures, neither does it commonly suffi-

ciently explain results obtained elsewhere by other bacteriological

analysts. Our floods come in March or later in the spring and the

soil washes most after it thaws out; the bacteria in waters like that

of the Illinois are more numerous before the ground thaws out and

before the great floods occur. The river is nearly always much

higher in June and July than it is in December and January, but

the numbers of bacteria are in the reverse order.

CAUSES OF PURIFICATION

This leads to the question so often asked and so vate an-

swered: to what cause or causes must the “ self-purification” of

streams be attributed? The various answers include dilution, sedi-

mentation, insolation, the effects of the plankton, etc. It is impos-

sible here to enter the discussion of the subject, but it may be said

at once that in the opinion of the writer the bacteria themselves con-

stitute the chief agency. They are preeminently the purifying

agents. When conditions are favorable they multiply with aston-

ishing rapidity, so that the progeny of one may become millions in

24 hours. In such situations as have been herein described they

are fermentation-workers. The organic wastes sent into the waters

are rich food for these little creatures. In myriad numbers they

attack it from all quarters. The solids are converted, in good part,

into gaseous forms and come bubbling up through the filth-laden

water. The supply rapidly decreases, the water becomes clearer,

the bacteria die either as a prey to other organisms or by starvation.

This, in a word, is the story. The more favorable the conditions,

temperature among other things, the more rapid the process. In

cold weather the fermentation is slower, the fermentable matter is

carried further down stream; the bacteria live, not so fast but

longer, and in the lower portions of the stream, distant from the —

place of pollution, are found in cold weather in greater numbers.

Qua titative TESTS

It has seemed impossible to present the results reported above in

briefer space, but there is little room to show those of the tests for

a "was to some extent found in the waters from every station upon the

_ fiver and its tributaries. Whenever and wherever the count showed

SUNIIINI ck store bacteria to the cubic centimeter this species ‘was com-

monly among them though it seemed to be evident that in the “ sur-

_ vival of the fittest” others longer existed and sometimes greatly

30% of the whole number, the lowest anywhere in the stream;

below Peoria about 90% and at Grafton about 45%. At the station

_ last named the waters of the Illinois and the Mississippi rivers proved

___ to be as near alike in this respect as in the total numbers of bacteria.

__ The collections from the Missouri River at West Alton always showed

SUTIN ‘cosets dacd wiry considerably qresior vorraitaah OF

_ positive tests for Bacillus coli-communis than did those at any time

_ for the Illinois River at its mouth or from the Mississippi River above

+ pnetand dna semin Such results were also true from the

t rehome edhe lorena apt iti

mentioned. Five samples were weckly taken at different points

_ across the stream in line with the St. Louis pumping works, called

_ Mitchell in the list of stations in the table, and the greater counts

_ showed very plainly and constantly the worse contaminations of the

_ Missouri, the percentage of all tests for the bacillus named rose to

_ about 80 of positive determinations. This seems bad indeed for a

municipal water supply, but in the light of the foregoing the charge

= cannot lie against the Chicago sanitary canal.

a ‘There is however a side-light here to which attention should be

4 _ drawn. The records show that typhoid fever is commonly much

a more prevalent in recent years in Chicago than in St. Louis, though it

4 ‘may be taken to be certain that Bacillus typhosus has very

often found its way into the stream along with so great numbers of

Bacillus coli-communis. The lesson is that the former soon dies out

_ and this is supported not only from theoretical considerations but

_ from all actual tests wherever reported from similar conditions.

There is not the slightest evidence known to the writer to show that

the typhoid bacillus, even for one germ, ever passed in the stream

116 T. J. BURRILL

from Chicago down to the mouth of the Illinois River. More prob-

ably the very many that have started in the current perished long be-

fore they reached the clearer water at Averyville.

On the other hand those which from the same source were poured

directly into the lake water and sometimes as directly pumped back

into the city mains, making the round perhaps in one or two days

were vastly more likely to carry infection to many people. Chicago

has suffered much and must continue to suffer in this respect until the

sanitary system is completed. Four-fifths of the sewage has for

many years gone into the river and with much greater dilution is now

so disposed of. When the other fifth shall have been added the

plague may cease and this without serious consequences elsewhere.

It cannot be held, however, that the water from any open stream in

a populated country is safe to drink. All cities must find other

supplies or inaugurate purifying processes, now known to be feasible,

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EXPLANATION OF PLATES

Plate XV

Map showing the drainage stream from Chicago to St. Louis and location

of stations at which collections of samples of water were taken for examina-

tion.

‘

Plate XVI ;

A graphic representation of the average number of bacteria in the water

at the stations named for the months of July, 1899 and 1900, before and after

the sanitary canal was opened. Some of the lines run more than once across"

the plate because of their great length. Note how short they are during the

lower course of the stream.

Plate XVII ‘4

Graphic representation of the identification of Bacillus coli-communis by

percentages of positive results of total tests. The stream seems freest from

this species at Averyville. The greater numbers at Mitchell appear to be due

to the contamination of the waters of the Missouri River received above this

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SYNCHAETA BICORNIS: A NEW ROTIFER FROM THE

BRACKISH WATERS OF LAKE PONTCHAR-

TRAIN, LOUISIANA

By J. C. SMITH

WITH PLATE

_ During the summer of 1902, while making some investigations on

_ the microscopic life of Lake Pontchartrain, Louisiana, I took a large

_ number of a species of rotifer which, on comparing with the known

_ Species of the genus Synchaeta, appeared to differ so much as to

warrant it being placed as a new species. At that time, Mr. C. F.

Rousselet had begun publishing his Monograph of the Genus Syn-

chaeta* and had given notice that he would describe several new

brackish-water species. In order to determine whether my take was

one of his new species I sent him some preserved material. He

The body of this rotifer (fig. 1) is of the usual Synchaeta type,

- é. e., cone-shaped ; this shape, owing to the very elastic nature of the

cuticula, is subject to considerable variation as to length and width.

as ainst extended form, it is sub-cylindrical, the dorsum being

___ Slightly convex and the ventral surface correspondingly concave. It

diminishes gradually towards the foot which is short, bulky, and

_ quite distinctly marked off from the body. This foot bears two

small peg-shaped toes, which are usually well separated while the

animal is in motion. The foot and toes can be retracted entirely

i alliliie the body of the animal.

The head portion, or corona, is well extended as a convex curve,

and on its summit and most ventral aspect has three small papillae,

_ ach bearing a tuft of cilia, above which are two pairs of tactile

_ setae, the inner pair apparently connected with the ciliary wreath;

*Rousselet, C. F. The Genus Synchacta: A Monographic Study, with descrip-

3 tions of Five New Species. Journal of the Royal Micros. Society, 1902.

122 J. C. SMITH

the outer lateral pair arising from heavy triangular processes. The

setae pierce the processes and are evidently connected with the brain

mass.

The auricles are of medium size and stand out at a right angle to

the body when they are extended.

On the dorsal surface, some distance below the extended auricles,

originate two very prominent horns, which are tubular

tions of the cuticula (fig. 1). These horns extend directly forward

and sometimes reach almost to the limit of the protruded corona.

Seen from above (fig. 1) they appear as cones, but when viewed

from the side when the animal is turning slowly and the head part

is retracted, they are seen to be true horns with their apices curved

downwards (fig. 2). These horns are always more or less wrinkled

transversely and can be extended and retracted to a considerable

degree. While they often reach almost to the limit of the extended

head parts, as noted above, it is not unusual to see very large forms

with horns quite small and very small forms with very long horns,

so that it may be concluded that the length of the horns does not bear

any close relation to the size of the animal.

The dorsal antenna is inconspicuous and is in its usual position.

The lateral antennae, if present, are very obscure, for the most care-

ful examination of very many living and dead animals failed to dis-

close their presence.

The brain mass bears three distinct red eyes—one cervical con-

nected with two frontal by two very obvious (in the living animal)

streams of red granules. The cervical eye, as a rule, is composed of

two segments which are not always of equal size, and together with

the frontal eyes, is surrounded by red granules which seem to be a

continuation of the granular streams. This peculiarity of three eyes

and their granular connections is shared with another brackish-water

species, S. littoralis Rousselet and a marine species, S. triophthalmus

Laut.

The large mastax corresponds in shape with that of most of the

species, while the fulcrum rests on two distinctly striated V-shaped

muscles. The muscles surrounding the trophi appear to be of a

tougher consistency than the other muscles of the body, for it was

with difficulty that these were sufficiently dissolved to get a fairly

good view of the trophi.

Fig. 4 represents an outline camera drawing of the trophi, which

SYNCHAETA BICORNIS: A NEW ROTIFER 123

__ eorrespond closer to the tremula type, as figured by Weber,’ than to

_____The fulcrum is very long and knobbed at its free or lower end;

each incus has five small teeth on its free edge. The manubria and

_ their wing-like processes can be best understood by consulting fig. 4.

On the ventral side of the mastax were found what appeared to

bea pair of densely nucleated salivary glands, which were seen only

The non-ciliated oesophagus is long and narrow and originates

well up on the dorsal surface of the mastax. The stomach, when

not unduly distended by food, is longish and ends in an intestine

which is quite distinct.

_ Offers nothing characteristic of this species. The lateral or excretory

__—s canals extend upward to a short distance above the summit of the

gastric glands, a peculiarity which seems to be characteristic of all

____ the Synchaetae. Excepting a small portion above the glands, they

_--—s are obscured by the ovary and distended stomach. The usual turn-

______ ings seem to be absent. There are three or four flame cells on each

canal, which are not indicated in the figure. The contractile vesicle

is of medium size and normal in position. The two foot-glands are

. Many of the muscles are distinctly striated and a few muscle-

fibrils are to be seen extending longitudinally through the horns.

a This little creature is very transparent, the only color seen being

a that of the stomach contents, which is usually yellow or golden. In

____ this connection, it is probably worthy of mention that all the rotifers

Of this species taken in July, 1902, were ornamented in a peculiar

Hl) munmner, Purplich spots of irregular shapes and sizes were distrib-

tuted over the muscles, brain, and all other internal organs, the cuti-

__ eula being free from them. Even the foot-glands and muscle-fibrils

__ f the horns were affected. The color of the eyes was modified by

| what appeared to be layers of this colored matter. Nothing in the

water in which these rotifers were taken could be correlated with

these spots.

“3 It is an exceedingly graceful animal in its movements, swimming

im a straight line, revolving on its long axis at the same time and

| ~—- Weber, E. F. Faune Rotatorienne du Bassin du Léman. Revue suisse de

q Zoologic, t. 5, 1898.

124 J. C. SMITH

turning abruptly from side to side. It has a habit of stopping sud-

denly without any apparent cause, and retracting completely within

the body its head, foot, and toes and extending and approximating

its horns. It remains in this curious condition (fig. 3) for a sec-

ond or two, when it again resumes its active state and starts off on

its mad chase. Another habit, which was noticed only when the

cover-glass was used, is that of “standing on its head "—#4. ¢., it

fixes its head to the cover-glass or slip while its body stands out at

a right angle.

These delicate animals, so accustomed to the rough water of the

lake, seem to be very susceptible to change of conditions, as they

perish soon after being transferred to quiet water, for four hours

after being taken but a small proportion were found still alive and

active, making it necessary to examine them soon after being cap-

tured. They vary much in size; measuring when alive and fully

extended from 200 microns to 300 microns long and from 100

microns to 150 microns wide across the extended auricles.

The oval egg is carried for a long time on the foot of the animal.

Lake Pontchartrain is a large body of water in southern Louisi-

ana and drains a considerable area. It is about 40 miles long with

a maximum width of about 25 miles and its greatest depth is about

18 feet. It connects with Lake Borgne and this again opens into

the Gulf of Mexico. It is the waters from the Gulf which make

the waters of both these lakes constantly brackish. The specific

gravity of the water of Lake Pontchartrain during these investiga-

tions varied from 1.006 to 1.010. The rotifers were taken from the

upper strata in water varying in depth from three to eight feet and

from one to two miles from shore and over a course of six miles.

At no time were any found in less depth than three feet and never

near shore or among algae or floating debris. They may therefore

be classed as belonging to the limnetic fauna.

They were first taken in July, 1902, and were then very abundant.

They continued to diminish in numbers until November, when they

disappeared entirely. In 1903 they first made their appearance in

May, were again found in abundance in July, when they again

began to diminish and finally disappeared in November.

The one characteristic which distinguishes S. bicornis from all

other species of the genus is the two dorsal horns.

Mr. C. F. Rousselet, in his Monograph of the Genus Synchaeta,

SYNCHAETA BICORNIS: A NEW ROTIFER 125

A Saar ciated Goacten 64 whlch seve oft tei aiater forme,

wo brackish-water, and seven marine forms. S. bicornis will in-

_ the brackish-water forms to three and the whole number of

ee a

SE hare stessa dada’ Goteou Cohen,

bicornis: Polyarthra platyptera, Anuraea curvicornis, Colurus

‘Schlaocerca dwersicornis, Brackionus wrceolaris, Mono-

a bulla, Monostyla lunaris, Distyla gissensis, and Noteus quadri-

Re woke Seetousied by specie Of the Sellowing distinchy

A BIOLOGICAL RECONNOISSANCE OF SOME

ELEVATED LAKES IN THE SIERRAS

AND THE ROCKIES

_ «extended from June 25 to July 15, so that one could speak

«some definiteness regarding comparative conditions in the two places

_ For the work on the lakes of the Pike's Peak region, Dr. F. E.

___ Clements proved an indispensable guide and assistant; the fine illus-

i trations of these lakes are made from his photographs, which were

MET Grecty placed at my disposal, Professors E. A. Birge and C, Dwight

of 127

128 HENRY B. WARD

Marsh were kind enough to take up the exact determination of the

Cladocera and Copepoda; and to Dr. R. H. Wolcott I am also in-

debted for many favors in connection with this study.

The fragmentary character of this work, which was carried out

under serious limitations as to time, apparatus, and supplies, is ap-

parent to all. My only excuse in presenting it lies in the desire

that it may be an incentive to others to take up under more favor-

able circumstances the study of these elevated lakes so interesting

in themselves, and so important in the problems associated with

them. This examination of these lakes was simply a reconnoissance ;

this report of it is at most an outline of the work which is to be

done.

Apart from the fragmentary notes jotted down in my field book

at the time, the results of my examination of the lakes are contained

in a series of thirty Birge net collections, made in the Sierra lakes

about July 1, 1903, and in the Pike’s Peak lakes about July 13, 1903.

These collections were made with great care to secure representative

material from the different bodies of water. They certainly do not

represent the entire limnofauna of the lakes. But they probably

give a fair general idea of the fauna at that time of year. Some rea-

sons for expecting a change later in the summer are detailed else-

where in this paper.

To the above was added a series of forty-five vials of material

collected by Mr. R. S. Gray in September, 1902. This represents

to some extent the autumnal life of the waters, although the collec-

tions were not made with the purpose of securing all types of life

in the lakes. °

No effort was made to examine the geology of the two regions;

but of both it is well known and admirably represented in the Pyra-

mid Peak and Pike’s Peak folios of the U. S. Geological Survey,

which include fully the regions studied. It was also impossible in

the lack of time and suitable apparatus to make any observations on

the physical characters of the lakes. Even the temperature had to

be estimated rather than precisely measured. Although many plant -

organisms were collected from the lakes in both regions, no accurate

work has been done in studying them, and only general statements

can be made concerning the limnoflora.

The first point to be considered is the character of the lakes stud-

ied. Between the lakes in the Sierras and those near Pike’s Peak

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 129

there are not inconsiderable differences which may be made clear by

a description and discussion of the chief features in each group.

__‘The Sierra lakes will be considered first.

‘Muir (1900: 122) speaks of the “ marvellous abundance of glacier

nestle in rocky nooks and hollows about all the high peaks and in

the larger cafions, reflecting their stern and rugged beauty and giv-

___ ing charming animation to the bleakest and most forbidding land-

_- -gcapes. From the summit of Red Mountain, a day’s journey to the

| east of Yosemite Valley, 42 may be seen within a radius of eight or

___ ten miles. The whole number in the Sierra can hardly be less than

1,500, exclusive of the smaller gems which are innumerable. Per-

haps two-thirds of them lie on the west flank of the range, and all

are restricted to the alpine and subalpine regions, those which once

____ brightened the lower regions having long since vanished by the fill-

ing in of their basins. Lake Tahoe is king of them all, not only in

size, but in the surpassing beauty of its shores and waters. .. .

F 2 With these comparatively unimportant exceptions, the lake itself and

all its grandly sculptured, ice-scored, and moraine-streaked basins

: - exist today in just about the condition they presented when first they

came to light toward the close of the Glacial Period.”

In a later publication (Muir, 1903:98) the same author adds the

following: “ Though the eastern flank of the range is excessively

a steep, we find lakes pretty regularly distributed throughout even the

____-‘ most precipitous portions. They are mostly found in the upper

____ branches of the cafions and in the glacial amphitheatres around the

The group of Sierra lakes which I studied lies on this precipitous

___ eastern flank of the range at the southwestern corner of Lake Tahoe

into which all of them ultimately drain (Plate XIX) through the

medium of a smaller body of water, known as Fallen Leaf Lake.

___ The latter is separated from Lake Tahoe by a low plain which was

___ apparently an ancient moraine, and which is not quite two miles in

width. While the lower northern end of Fallen Leaf Lake lies in

the plain, the upper end is encompassed by mountains, especially on

the west, where the steep flank of Mt. Tallac rises directly from the

water's edge. The valley in which Glen Alpine Springs is located

trends westward from this end. It is narrow, with cragged sides

and little vegetation beyond that which is crowded together near the

130 HENRY B. WARD

stream. The floor ascends so rapidly that the channel of the brook

is little more than a succession of rapids and falls, in some cases of

considerable height, with occasional pockets of a swampy nature

bearing an abundant plant growth. The lakes occur as a series of

larger pockets, in some of which the filling in has progressed so far

as to produce a shallow, marsh-edged basin with a distinct rapidly-

flowing stream through the center. Others present themselves as

deep basins with rocky, often precipitous shores, and little current

apart from the immediate region of inlet and outlet. The shallower

lakes are also the lower in the series. I have been unable to ascer-

tain the exact altitude of these lakes, but this factor can be calcu-

lated sufficiently exactly from the topographic charts of the U. S.

Geological Survey, from which I obtained the following list of ele-

vations above sea level: Lily Lake, 2010 m.; Grass Lake, 2194 m.;

Susie Lake, 2347 m.; Heather Lake, 2377 m.; Half Moon Lake,

2500 m.; Lake Aloha, 2470 m. ; Gilmore Lake, 2530 m. The figures

given are probably 5 to 15 m. below the true altitude.

Inflow and outflow are large in proportion to the volume of the

lakes, especially in the spring and early summer, while the snow

accumulated during the winter is melting rapidly. Later in the

season the volume of the streams is said to decrease markedly. The

fluctuations in the level of the lakes due to this factor are, however,

inconsiderable, since the outflowing streams possess very little depth.

At the time of my visit the upper lakes were fed directly from melted

snow (Plate XXII), and at many points on sheltered slopes great

masses of snow reached into the water, while miniature icebergs

floated on the surface. The temperature was accordingly low and

conditions were typically glacial.

By the time the water had reached the lower levels, however, it

had become much warmer and all snow and ice had disappeared

from the immediate environment of the basins. The color of the

stream had also acquired a distinct brown tone leached out from the

forest mould through which it had filtered. It was everywhere clear

all kinds whatsoever.

Lily Lake, the lowest of the series, had been filled in considerably

and was surrounded by swampy areas covered with plant growth

and shallow flats on which at the time of my visit the first traces of

a sub-aqueous vegetation were beginning to show themselves. It

as.

tae

re wT eee

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 13f

__was the smallest and clearly also the most decadent of all these water

_ basins. Grass Lake was larger, much more open and of greater

_ average depth. The upper end was apparently closed by a thicket

“of partly submerged alder, through which the water found its way

__ without any proper channel that was visible. There were also banks

__ of eel grass that covered parts of the bottom beyond the alders ; but

except at the upper end there was no approach to a swampy condi-

____ In the higher lakes the shallows, swampy areas, and water vegeta-

_ tion were either minimal or absent. The lakes were apparently

_ Of possessing a single inlet, water was pouring down every rocky

defile from the snow banks above and had worn only shallow chan-

_ mels in the debris of the mountain side, while the debouchment of

these rivulets had often no trace of the formation of a delta. These

__ lakes are young and the process of destruction had not yet begun.

Pe The group of lakes in the Rocky Mountains which were made

the object of my study, lie in the valley of Beaver Creek, about 7.5

___ km. (4.5 miles) south-southeast of the summit of Pike’s Peak (Plate

_ XXIII). They are known collectively as Seven Lakes and lie at

an elevation of about 3,300 to 3,310 m. above sea level. The indi-

__ vidual lakes are near together and all empty into Middle Beaver

_ Creek. About 2 km. distant lies a small water basin near the saddle

a _ of a divide; it is without visible inlet and outlet and is called Dead

Lake. Its altitude is approximately 3,340 m. above sea level. It

4g __ is of small size and insignificant depth.

3 by an extensive swamp margin, while others are of considerable

depth. At the time of my visit the snow had entirely disappeared

_ from the proximity of these lakes, and even from Mt. Garfield, which

meee shove them. The surface water was not noticeably cool to

__ the hand and in the shallow lakes even apparently warm. Though

much higher than the lakes of the Sierras, these water basins present

nothing of the typical glacial conditions already described for the

____ In Dead Lake July 13, 1900, the surface temperature was 14°.4 C.,

_ the bottom 13° C. At Ribbon Lake the temperature was 14.°2 C.

_ alike at surface and bottom. The temperature of the air varied dur-

_ ing the day from 13°.6 to 18° C,

132 HENRY B. WARD

The amount of inflow and outflow was small comparatively and

the normal fluctuations in level slight. One can see that within

comparatively recent times several of these lakes have had a greater —

extent than at present. Within a year, however, they have been

connected with the city water supply of Colorado Springs and the

level in one of the largest, Mirror Lake, has been reduced so much

as to lay bare the entire lake shelf. This result appears clearly in

a comparison of the two illustrations (Plates XXVII and XXVIII).

The changes contemplated are certain to effect notable alterations

in these lakes and also in their fauna.

Viewed as a whole these lakes are old, and some of them are just

about to disappear, if natural conditions persist. Very little, if any,

of the rocky sides of the mountain enter into their boundaries; the

shore is made of broken fragments and detritus, which have also

filled the basins in great part. The lakes lie exposed to the sun and

wind, not shut in by high banks, nor protected immediately by heavy

forest growth. The surrounding territory has a large amount of

soil and supports a vigorous growth of mountain vegetation. In

most respects then these lakes stand in sharp contrast to those in

the Sierras already described.

Zschokke gives (1900: 40) as the picture of a typical alpine lake

the following: Water basins of more than 1,500 m. (5,000 ft.) alti-

tude, of variable, but mostly insignificant area and very different

depth. The bottom and shore show in their character manifold local

differences, and the general external features vary equally. Drought

and avalanches may threaten the existence of the basin. The Chara-

ceae, algae, and mosses play the chief part in the flora and the lit-

toral plant world generally disappears rapidly with increase in alti-

tude. The inflow is poor in nutriment, and often carries cold water

exclusively or in predominant amounts, while periodic increase or

decrease of the inflow often produces very important oscillations in

the niveau of the lake. The inflow or outflow is often subterranean.

The quiet of the surface is almost undisturbed. The water tempera-

ture, even in midsummer, is low, wintry. Little difference exists

between surface and deep temperatures, between summer maxima

and winter minima. The ice covering lasts long. The chemical

composition of the water is very variable. In Alpine lakes the most

important and most constant conditions which present themselves to

the fauna are northerly, glacial. Low temperature of the medium

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 133

abited, long continued winter with heavy covering of ice, sparse

fclopment of the flora. Copious inflow of snow water or cold

er, poor in food and often unsated with oxygen, and with large

amount of mineral matter in suspension. Other conditions are as

n water basins of the plain. Glacial conditions control the compo-

sition of the fauna of alpine lakes and the animals of elevated lakes

j are still in the midst of the glacial epoch.

__ The general limit assumed by Zschokke (1900: 2) which confines

his work to lakes having an altitude of more than 1,500 m. is recog-

_ mized as more or less arbitrary, and yet it corresponds well in the

_ region he studied to the other limitations of strictly alpine lakes.

This is not only the case in Switzerland where Zschokke worked, but

also in the Tatra lakes, according to Wierzejski and von Daday, in

the elevated lakes of the Pyrenees, according to de Guerne and Rich-

ard, and in the French Alps and the Pyrenees, according to Dele-

__ The same conditions do not obtain on this continent. There are

lakes in Colorado above the 1,500 m. line (about 5,000 ft.) which,

located on elevated plateaus, have all the characteristics of flat land

lakes. One must usually go higher than this limit to find water

__ basins to which the term “alpine ” may properly be applied. Appar-

ently no such limit, even of an approximate character, can be used

_ in this country since conditions at the same elevation evidently vary

in different regions. That the limit of alpine lakes does vary my

own observations in the White Mountains (New Hampshire) the

' Rockies (Colorado) and the Sierras (California) show me unmis-

_ takably; what may be the extent of this variation and what the

approximate altitude of characteristic alpine lakes in different regions

can only be determined by much more extensive observations than

I have made as yet.

_ That latitude as well as altitude is an important factor in the com-

parison of elevated lakes has been recognized by Forbes. In con-

trasting the two largest lakes in the regions he studied he says

1893: 236): “ Flathead Lake is over 200 miles [320 km.] farther

northward than Yellowstone, but the latter is 4,775 feet [== 1,455m.]

the higher above the level of the sea.” Among others, “ These differ-

“ences tend largely to neutralize each other.”

| The Sierra Lakes visited were much more clearly glacial in their

_ environment than those near Pike’s Peak and yet they lie about 1,000

134 HENRY B. WARD

m. lower than the latter, while in latitude they are almost identical,

as the line marking 38°50’ N. Lat. crosses both regions (Plates XIX

and XXIII). It is clear, however, that conditions are not so con-

stant as in the Alps and questionable whether the same relative con-

ditions persist between the lakes of the Sierras and Rockies through-

out the year. In the course of the summer the snow in the Sierras

disappears (Plate XXIII), the inflow becomes scantier in amount

and probably somewhat higher in temperature, while the lakes them-

selves, no longer under the influx of a large amount of cold water,

must rise in temperature noticeably towards late summer. In the

Pike’s Peak region these conditions had already come, and the change

towards fall would bring even higher temperature. In the Alps the

persistent snow masses and ice fields keep down the temperature of

the inflow.

Another noteworthy difference between the elevated lakes of this

country and of Europe is found in the greater area of our own. Lake

Tahoe, lying at an elevation of nearly 2,000 m. (6,225 ft.) has an

area of over 50,000 ha. (193 sq. mi.), Shoshone Lake, studied by

Forbes (1893) has an elevation of 2,360 m. (7,740 ft.) and an area

of about 3,100 ha. (12 sq. mi.), Lewis Lake and Heart Lake, of

nearly the same altitude, have from 780 to 1,300 ha. (3 to 5 sq. mi.)

of area (Forbes, 1893), while Yellowstone Lake, also at an altitude

of about 2,360 m. (7,740 ft.), measures 36,260 ha. (140 sq. mi.).

These are by no means isolated cases, as a glance at the contour map

of the U. S. Geological Survey will show. The 1,500 m. (5,000 ft.)

contour line encloses many water basins of considerable area; some

of these are saline, a few, as Mono and Owens lakes, California, ex-

cessively so, but others contains water of extreme freshness and

purity. Mingled with these large lakes are myriads of smaller. As

Russell says (1895:63): “ These lakes are of all sizes, from mere

tarns across which one might spring with the aid of an alpenstock,

to broad plains of blue, many square miles in area, and worthy of

comparison with the most beautiful mountain lakes of other lands.”

The Sierras are peculiarly rich in such water basins. With Lake

Tahoe,’ “ the gem of the Sierras,” at one extreme of size, and with

the tiny rock pool, or swamp-filled basin at the other, the series em-

braces every variety of contour and environment. Among the

é *For a splendid description of this incomparably beautiful sheet see Russell —

1895 : 63).

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 135

ock: icicle ‘peed dees ure tad tuee'sdeaiefomn, aed Tie the

ike oe suas ctibidy davcsed, are for the most part well on

the way to final disappearance.

The lakes in the Sierras are about of the same altitude as those

ed by Zschokke in Switzerland, and at the time of this

study presented the same typically glacial features. In other respects

also they are in general agreement with his descriptions, save, as

already noted, that the disappearance from the mountains of the

‘snow and ice in late summer is undoubtedly accompanied by a rise in

temperature and a consequent greater thermal range than is found

in the lakes of the Alps.

‘The lakes in the Pike’s Peak region of the Rockies are 800 m.

higher than any in the Sierra group studied ; the conditions are, how-

ever, much less distinctly glacial. In Dead Lake, the shallow water

thad already attained a moderate temperature (14°.2 C.) and after

two months of summer sunshine would be decidedly higher in spite

of the cool nights and cold rains of that elevation. Such lakes will

furnish, accordingly, only transiently glacial or northern conditions

_ during the spring and fall. And these periods will be interrupted

by an interval in which the temperature conditions are nearer those of

the lakes in the flat land. The summer interval will be especially

marked in those water basins which are very shallow like Dead Lake,

which is also dependent upon seepage for inflow and outflow, and

least so in the deeper ones such as Mirror Lake. Locally the latter

‘is said to be “ bottomless ” ; it is certainly more than 10 to 15 m. deep

at the maximum. Ribbon Lake measures about 8 m. at the deepest

point, while none of the others much exceed one meter in depth and

over the greater part of their area the water has a depth of only one-

_ In one further particular both series of lakes studied differ notably

from the lakes of the Alps; they all lie below timber line, as an ex-

‘amination of the plates will show distinctly. Two results of this

; affect the biological character of the lakes: A considerable

amount of plant debris is washed into the waters, which by its pres-

‘ence and gradual disintegration influences the food supply. In the

second place, the living trees, as well as the dead fragments, attract

additional members to the terrestrial fauna which sooner or later, and

one form or another, add to the water fauna or furnish food for

the latter. The forms concerned are chiefly insects, of which a very

136 HENRY B. WARD

considerable number depend upon the timber for their presence in

the region. The relative importance of insect larvae in the water

fauna is discussed elsewhere in this paper.

The fauna of elevated lakes has been subjected to a careful tedy

by Zschokke, whose results have appeared in a series of papers on

special regions extending through a number of years and culminating

in the splendid crowned memoir of the Swiss Naturalists’ Society

(Zschokke, 1900). The characteristics of elevated lakes are pre-

cisely stated therein in terms which also apply, as already noted, to

the lakes of the Sierras and the Rockies that were the seat of

my observations. Zschokke sums up these features as follows:

(1900:377) “The truly characteristic external conditions of the

alpine lakes are glacial: a low mean temperature, inflow from melting

snow and ice, long continued ice covering, poverty in plant growth

and fluctuations in level. The elevated water basins still stand in

regard to physical and chemical relations in the midst of the glacial

epoch. Hence their fauna bears a distinct glacial stamp in composi-

tion, origin, distribution, manner of life, and structure of its repre-

sentatives.” The description of the physical features applies to the

lakes under discussion, as the description and views reproduced here

will show; it remains accordingly to examine the character of the

fauna.

At other places in Europe investigations have been made on the

fauna of elevated lakes; they are, however, less intensive than the

work of Zschokke just noted and need no special mention here.

Data concerning them may be found in the full bibliography given

by Zschokke (1900: 382).

The earliest study of the fauna of elevated lakes in this country

was that of Forbes (1893). There are to be sure, earlier references

to the fauna of our mountain lakes, but casual observations made

in connection with various expeditions and surveys, or the descrip-

tion of a single species collected by some traveller cannot be con-

sidered a study of the lakes themselves. Isolated observations of

this type are referred to both in the paper of Forbes (1893) and in

those by Beardsley (1902, 1902a). Forbes investigated the lakes of

the Yellowstone National Park in Wyoming and of the Flathead

region of Montana, spending two seasons, 1890 and 1891, in the

field. The lakes examined were many of considerably size and depth;

the highest elevation from which material was collected was Mary

a BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 137

Lak ithoes a000 te: (8000 8). The extensive collections in-

- cluded a number of new forms apparently characteristic of elevated

_ lakes. Unfortunately these collections have never been described

iin detail. This paper contains many points of great interest and

. will be referred to in detail under later paragraphs.

_ While the records of Forbes (1893) concern the Rocky Mountain

__ Shain, they were made much further to the north than those from the

_ Pike’s Peak region. Recorded studies on forms from Colorado are

fare and I have traced out but a single recent author. Beardsley

(1902, 1902a) has recorded a considerable number of species from

Miaiietado, both of Ealomostrace and of Protosce. Doubtless some of

_ these came from lakes which are strictly alpine. All of them were

taken above 1,200 m. and yet very few are in any way characteristic

_ Of elevated regions. The significance of this will be pointed out later.

i _ He also gives complete references to previous papers on these forms

i eee contain records of their occurrence in Colorado.

So far as the group of Sierra Lakes is concerned almost the only

= SENG thee atural history of this region are given by Price (1902),

_ im a pamphlet which embodies the results of several years personal

studies by the author, and his students, on the higher animals and

_ plants found in this territory. The birds and mammals are well

_ treated in concise form, the fish and reptiles somewhat more briefly,

_ and the discussion of the plants is confined to trees and shrubs.

_ While the pamphlet does not include any immediate reference to the

aquatic plants or animals, it contains much of great interest in the

consideration of the general environment of the lakes.

In a brief paper (Ward, 1903) I have related some of the observa-

Slits made in the series of lakes near Glea Alpine, and have pointed

_ out the relation in which these observations stand to the planting of

_ trout in these waters.

4 Some collections of Entomatraca, made in the lakes of the Sierras,

_ by G. Eisen, were studied by Lilljeborg and reported by de Guerne

and Richard (1889). The localities are given in general terms,

__ except for Epischura nevadensis, which was collected in Lake Tahoe

_ and Echo Lake ; these water basins lie very near the lakes under con-

sideration (see Plate XIX).

___ The fauna of the Sierra lakes was noticeably scanty in amount in

_ all regions ; neither in shore nor in open water was one able to find

138 HENRY B. WARD

or in variety of species. Only once in a very shallow pool by the side

of the trail did I find a moderately populous water basin and even

here conditions were far behind what would have been met with

under similar conditions at a lower level.

The same scantiness of animal and plant life was observed in the

deeper lakes in the Pike’s Peak region. In the shallow water basins

here, however, the fauna was distinctly richer both in species and in

individuals. From bottom hauls came a rich flora of unicellular

algae and a more numerous fauna than was elsewhere obtained.

The records from the lakes of the Pike’s Peak region represent the

greatest altitude from which the limnofauna has been reported in

this country, and they also surpass any from European countries.

As already pointed out mere altitude cannot be considered as deter-

minative in comparing two elevated lakes. The most important

factor here, as in the distribution of marine life, is temperature, and

this is related in part to altitude, but also to other factors, the most

general of which is latitude. A striking instance of this is drawn

from my collection. Holopedium gibberum was found in the Sierras

at Susie Lake, at an elevation of about 2350 m. above sea level.

The greatest altitude at which it had been collected previously was

Lewis Lake (Forbes, 1893), at almost exactly the same level, but in

the Rocky Mountains. The same species occurs in Gotthard Lake,

Switzerland (Zschokke, 1900), at 2,100 m. altitude, and in lakes of

the Hohe Tatra, Bohemia, up to 1,795 m. It also occurs in mountain

lakes of Norway at altitudes of less than 1,000 m., in Iceland in a

shallow pond on an elevated plateau, which in any event is not very

high above sea level, and finally in lakes at sea level in Greenland.

More accurate and detailed consideration of the various points of

occurrence from among which these instances have been taken would

probably show them to be uniform in temperature conditions. The

species is one which evidently prefers clear, cool water, finding this

at different altitudes (or times of year?) in different latitudes.

It is not easy to find examples so distinct in their indications as

the one just cited. Usually the evidence is partial; but it may be

found in one form or other in the observations of many investigators

of mountain lakes. I shall refer only to two instances taken from

the same source. Zschokke furnishes many points illustrating this

feature. One of the most striking is his statement (1900: 349) that

the lakes of the Bohemian forest, investigated by Fric and Vavra,

’

. BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 139

~ conta i typical alpine fauna, although they lie at an altitude of

lh ipagpeaagroadly Zschokke also gives (1900: 350)

am extensive table of the maximum altitude reached by some sixty

_ species in the lake of the Rhitikon, St. Gotthard, St. Bernard, and

_ Upper Engadine regions of the Alps. This furnishes unmistakable

‘evidence of the presence of a species at greater altitudes in the region

liaeirtant feature thet the fauna varies greatly from point to point

both quantitatively and qualitatively by virtue of the general varia-

____ tion in external conditions. But all in all when both European and

ee ee

_ Certain notes regarding particular groups or individual species of

_ the lake fauna call for special record here. The material could not

be examined on the spot ; consequently little definite information was

Ee ae Se Frome and Rotifers which ware passage,

_____ The paucity of records concerning Branchipoda from alpine lakes

____ has been commented upon by Zschokke (1900: 188) who could find

im all hardly half a dozen notices of their occurrence in such water

____ basins of all lands. Their presence and relative abundance in the

Waters of Colorado are already well known through the work of

Packard (1883). Beardsley (1902) has added five species to the

faunal list of the state. The largest organism I found in Dead

Lake was a branchipod which was present in considerable numbers.

_ This form was Branchinecta coloradensis Packard which was origi-

nally collected at about 3,800 m. altitude near Grays Peak, Colorado.

Its closely related to B. paludosa (Miller) which occurs in northerrt

‘Scandinavia and Greenland. Packard (1883: 339), says of this

> form, “ They thus live under almost exactly the same meteorological

conditions as B. paludosa in northern Labrador and Greenland, the

near the snow line on Colorado in August being about

the same as that of northern Laborador and Greenland in August.”

ae. eae

The twenty species of Cladocera I obtained extend the range of

Smee species into a territory from which the group has not been

_ feported hitherto. The vertical distribution of these forms has also

seem greatly increased. This is of course true of the American

140 HENRY B. WARD

species heretofore known only from the flat land of the eastefn or

central states, but is equally the case with the cosmopolitan species

like Chydorus sphaericus, collected in the Rockies about 700 m. above

any previous record. European species of an alpine character, such

as Daphnia longispina occurred here at an altitude equally greater

than heretofore recorded. Such occurrences conform to the differ-

ences in the character of the American and European regions, which

have been discussed in full in the earlier part of the paper. More

striking is the presence of some forms, Bosmina longirostris,

Eurycercus lamellatus, Polyphemus pediculus, in the Sierras at alti-

tudes from 500 to 700 m. higher than Zschokke (1900: 156) has

found them in the Alps, although conditions in the two regions, as

already noted, are closely similar.

In the distribution of species in the two groups of lakes it was

noteworthy that the new form described by Professor Birge, Macro-

thrix montana, occurred both in the Sierras and in the Rockies, and

that Diaphanosoma leuchtenbergianum, heretofore known only from

a single elevated lake, Lewis Lake in the Yellowstone region of the

Rockies (Forbes, 1893), was collected from an almost identical alti-

tude in the Sierras. This form has not been reported in Europe

from any elevated water basin.

The Copepoda were present in almost every collection I made,

although the number of species is small in comparison with the Cla-

docera. Diaptomus signicauda is a small form, viewed as one of

the most peculiar of American species and reported hitherto only

once from collections made in the Sierra Nevada mountains, Cali-

fornia, at an elevation of 2,400 to 3,000 m. (8,000 to 10,000 ft.) above

sea level. Its occurrence in the Sierra collections is natural, although

the localities represented here lie on the eastern flank of the range,

while it was probably collected before on the western slope. It was

taken here at a slightly lower elevation than previously reported.

Exceedingly interesting is the closely allied new species described by

Professor Marsh (p. 147) which occurred only in the Rocky Moun-

tain lakes. -

Diaptomus shoshone “has never been found outside of Yellow-

stone Park” (Forbes, E. B.). The abundant occurrence of this

conspicuous species in the lakes of the Pike’s Peak region extends

its range considerably along the chain of the Rockies; and also its

vertical distribution which now includes 2,300 m. (Yellowstone

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 14I

iby §.500 mm. (Pike's Peak region). Extended observations are

necessary to determine how much of this may be due to the factor of

latitude discussed above. This form may be regarded as a charac-

FE _ teristic alpine species in the Rocky Mountains.

____Epischura lacustris, a common species in the deeper, clearer lakes

of the northern United States, was noted by Forbes specifically as

__ wanting in collections from Yellowstone Park, while in the Flathead

River system, Montana, it was apparently replaced by another num-

ber of the same genus, E. nevadensis. Forbes was inclined to

attribute the absence of the common E. Jacustris to the altitude ; and

"yet the observations made in the Sierras show that this can hardly be

the correct view, for this species occurred in collections made in

September, 1902, from at least four of the lakes. Furthermore, these

included Lake Gilmore, the most elevated of the entire series (2,530

_ m.). ‘This record extends notably the vertical range of this species,

and also of the entire genus. Regarding the latter point, Forbes

_ gays (1893: 254), “ The absence of all representatives of this genus

_ from the lakes of Yellowstone Park evidently adapted to them, hints

_ strongly at a limit of altitude to their distribution. The highest

locality from which any species has been reported is Lake Tahoe,

____ said to be 6,250 feet above the sea; while the lowest lake of suitable

___ size in Yellowstone Park from which our collections were made, was

____ 1,200 feet higher than this.” This topographical difference does not

__- measure the biological difference, however, as the lower location is

__ also more than five degrees south of the Yellowstone lakes. As the

_¢levation of Lake Gilmore, the highest record of this species, made

in this study, is nearly two hundred meters above the Yellowstone

takes, it is evident that the question of altitude merely is not decisive.

_ The query raised in Forbes’ concluding sentence falls under the

___ problem of the influence of latitude upon the vertical distribution of

| the fauna, and serves to emphasize still further points already dis-

cussed in this paper.

_ ‘The absence of Epischura nevadensis from these collections is

especially noteworthy, since it was originally collected from Lake

_ Tahoe and Echo Lake in the immediate vicinity and connected with

the same water system as the lakes examined.

' Among the Cyclopidae collected, C. serrulatus and C. albidus

= ishould be a peep ey according to Forbes, as very common mountain

¢g as , aw 6a) ; this lake is 1,902 m. above the sea.

142 HENRY B. WARD

One peculiar feature which was recorded several times in my

field notes, seems to be definitely related to altitude. Says Zschokke

(1900: 130), “ an extremely striking characteristic of the diaptomids

of alpine lakes lies in their brilliant red coloring.” This brilliancy

of coloring does occur among the diaptomids of lower elevations,

and varies much in the same species from point to point; yet it is

far more general and more striking among the alpine forms. The

red color occurs in other groups, of which Zschokke names hydra,

the Cyclopidae, many Turbellaria, some Annelida, and at least one

rotifer. Apparently the color is transmitted secondarily to the other

forms along with the Copepoda used as food. This view is supported

by the fact that hydrae when starved bleach out. Low er

clearly favors the development of this coloring matter.

Forbes (1893) published the first records on the abundant occur-

rence in elevated lakes of several red species: Diaptomus shoshone,

of which the adults of both sexes are blood red throughout except

the egg sac of the female which was purple; Diaptomus lintoni, and

a brick red hydra (p. 222). All of these finds were in the Snake

river system, at an altitude of approximately 2,277 m. above sea

level.

Such a red color has also been noted in alpine lake forms by Elrod

and Ricker (1902). Hydra taken in Echo Lake, Montana, was con-

spicuous by reason of the bright coral red coloring and a reddish

Daphnia is abundant in the same water. The authors fed such red

hydrae five weeks on colorless entomostraca but in contrast with the

results obtained by Zschokke, observed no noticeable dimming of the

color. One of the most striking features noted in the Sierra collect-

ing was the presence of similarly colored Entomostraca. The ex-

treme case occurred in Gilmore Lake when apparently the entire haul

was made up of a copepod’ so deeply colored red as to stand out with

great distinctness in the water. The latter was at the time ice cold

and although the surface was free from ice, the snow banks lay near

the margin on all sides. Lake Gilmore is the most elevated of all

those visited, being about 2,530 m. above the sea.

In an earlier paper Elrod (1901: 76-78) reported Diaptomns

ashlandi in McDonald Lake as “ conspicuous on account of its red

*This form does not appear in the list by Professor Marsh. It was recorded

in my field notes as a large brilliant red copepod and I recall its appearance dis-

tinctly, but the vial of specimens has

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 143

” Daphnia pulex from Daphnia Pond (elevation 914 m.) was

PPE, abst oa se a

from the Seven Lakes Macrobiotus sp. was also

_ near Susie Lake, and from Lake of the Rocks and Dead Lake in the

Rockies. Numbers of an immature Planaria were also present in a

_ bottom haul from the latter place.

_ The number of hydrachnids collected was not large but rather

widely distributed. One form of Notaspis was collected from a small

pond near Susie Lake at Glen Alpine and from Lake of Rocks near

__ Pike’s Peak. From the former young of Afar crassipes were also

_ taken and from the latter an Acercus; Limnesia and Curvipes occur

im the September, 1902, collections from the lakes of the Sierras, and

one specimen of Lebertia was found in the collection I made from

Dead Lake at Pike’s Peak. The records of these forms from lakes

____ im the Rockies conform to the records of the other groups in being

_ the highest (3,300 m.) yet made for these species, and probably rep-

____— resent the greatest altitude at which water-mites have ever been col-

lected. Undoubtedly more extensive collecting would have added

| _—s«*Thysanura and Thrips were observed in both localities, though

____ mo more precise determination of the forms was attempted.

a _ Among mollusks Pleurocera and Pisidium were observed in the

lakes, while Sphaerium was obtained in Susie Lake,

igre

_____ Insect larvae were relatively abundant in all the collections and

im fact appeared to form the predominating element in the fauna.

_ There were larvae of several Hemiptera, Diptera (Culex, Simu-

_ kium?) and Coleoptera, in the collections from the shallower of the

a Seven Lakes and also from the temporary pools in the Sierra region.

_ From the deeper lakes in the Sierras I collected only Chironomid

larvae which were present in nine hauls out of ten, being the most

___ conspicuous organism taken. These were also present in about half

_ the hauls made in the Rockies.

144 HENRY B. WARD

Not only were insect larvae abundant in the pools of the Sierra

region, but adult forms were seen in the air and on the vegetation

about the water. The air was relatively much warmer than the

water so that terrestrial and aerial forms had developed in advance

of the limnofauna. It seemed as if the mature insects had

their way up from lower altitudes into this region by the aerial route

and were taking advantage of the first appearance of suitable water

basins which afforded a place to deposit their eggs. Thus the insect

fauna was developing in advance of the other elements. Of the

larger aquatic forms we saw nothing beyond the insect larvae save

that in a single haul were two large Amphipoda.

Two observations contributed evidence in favor of the view just

stated. I had the opportunity of examining the stomach contents

of a female mallard duck which was shot on one of the lakes, and

preserved for the U. S. National Museum. The duck was well

nourished and the stomach well filled with food ; but there were none

of the various small crustacea which usually constitute a very large

part of the food of these birds. Not a single part was found which

even doubtfully could be referred to such forms; almost the entire

mass of stomach contents was composed of mature insects, among

which were a few insect larvae. Substantially the same was true

of the stomach contents of the trout which were caught during the

same time.

I was unable to ascertain what was the original condition of these

lakes in the Sierras as to fish fauna. The precipitous character of the

outlets, and the limited volume of the outflow, together with the

landlocked character of the system which does not reach the ocean,

but terminates in saline lakes on the desert, all make it probable that

they were entirely without fish in the early days. The impassable

character of these outlets in some instances at least may be judged

from the photograph of Grass Lake (Plate XXI) where in the

midbackground appears the outlet of one of the higher lakes spread-

ing like a film of gauze over the face of a precipitous cliff.

Within recent years, however, numerous plants of trout fry have -

been made in the lakes with varying degrees of success. The trout

caught in different lakes varied much in robustness; from some they

were plump and well nourished, from others they were evidently

starved, presenting a gaunt, cadaverous appearance, which the fisher-

men described as “ all head and tail.” Evidently such had obtained

; BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 145

sean iaiticicais Wbbkats the’ whihde end hed ted en cpiportonity

_ to improve their condition as yet since they came from the highest

_ lakes which were indeed only partly free of their ice covering. The

"fish which came from the lower lakes were taking the fly eagerly and

were voracious after larvae and mature insects, as evinced by the

_ contents of the stomach. If their winter fare had been as limited

as that of the others, they had recouped their fortunes on a spring

diet of insects which, commensurate with the earlier opening of their

basins, came much in advanced of the disappearance of ice from the

In view of these facts one may ask whether the normal winter

_ fauna of these lakes is not scanty for the support of fish life, so poor

im fact as to set a distinct limit to the number of fish which may be

planted under present circumstances. The limitation will be more

apparent in the higher lakes, both on account of the poorer fauna

and of the longer closed period, than in the lower basins.

It is also suggested from the foregoing data that the question of

_ food supply for the trout in this region is largely an entomological

_ ome, at least at the period in which these observations were made.

Of course more extended study is necessary before these conclusions

____ are finally accepted, but the uniform testimony of all data obtained

_ cannot but be suggestive. There has certainly been some modifica-

____ tion of the aquatic fauna due to the introduction of the trout, and it

‘may yet be possible to determine this in a broad way by the examina-

tion of virgin waters in the vicinity. Such exist and their study

would yield data of great value on the question connected with the

_ future of the fish. But these problems as well as those which con-

cern the adaptation of the trout to a new environment that compels

_ some modification of the usual habits of the species, lie really beyond

(dat paserng apr anand

____ The biological problems which suggest themselves in the Rockies

Bias of a very different type. Trout have been seen in Mirror Lake

_ and salamanders occur in both Mirror and Ribbon lakes. But on

___ the whole the lakes are unfitted to support a fish population. Their

_ felation to the city water system of Colorado Springs indicates not

_ only irregular changes in level which may be extreme at certain

_ times, but also modifications of shore and immediate environment

146 HENRY B. WARD

element in the fauna of a mountain lake by a considerable change in

level alone.

The immediate surroundings are sure to be modified also. Within

recent years the quality of the water supply has suffered greatly from —

the caterpillars on the aspen trees along the banks of the mountain

streams. These larvae became at times so abundant and dropped

into the water in such numbers that the destruction of the aspen

trees near the bank was ordered and has been carried out in great

part. In connection with the use of the basins for water storage the

shores will be cleaned up, and the shore fauna largely annihilated.

The bottom will also be freed of all debris and ultimately the process

will leave only that part of the original fauna which was not de-

pendent upon either shore or bottom, namely, the true limnetic

forms. “4

Report ON THE CopepopA By C, Dwicut MarsH

Species of Copepoda Found

Diaptomus signicauda Lilljeborg.

Diaptomus shoshone Forbes.

Diaptomus nudus sp. nov.

Epischura lacustris Forbes.

Cyclops viridis var. americanus Marsh.

Cyclops albidus Jurine.

Cyclops serrulatus Fischer.

In regard to the occurrence of the species of Cyclops there is

nothing of any especial interest. The species are of world-wide

distribution, and would be found anywhere under similar circum-

stances. I have listed Cyclops americanus as a variety of viridis

This is not yet proven but I think it is a fact which the recent paper

of Miss Lehmann (Lehmann, ’03) goes far to prove. The variety

americanus seems to be the common form in these collections rather

than brevispinosus.

Epischura lacustris was found in four of the lakes, viz., Lake of

the Woods, Strawberry Lake, Grass Lake, and Gilmore Lake.

Diaptomus signicauda occurred in four of the localities, Lake of

the Woods, Susie Lake, and in a pond in Glen Alpine.

Diaptomus shoshone and D. nudus occurred only in the lakes on

Pike’s Peak. D. mudus appeared in Lake of Rocks, Mirror

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 147

Dead Lake, and Lake Michigan. D. shoshone was in the

list with the exception of Lake Michigan.

D. nudus is closely allied to D. signicauda which was first reported

m California, and probably is widely distributed over the moun-

regions of the western part of the United States.

Diartomus suosuone Forbes. (Plate XXX, fig. 3; Plate XXXI,

figs. 1-3.)

This beautiful species is very striking because of its size and color.

It is the largest described American species except D. stagnalis

Forbes. It is highly colored in blues and reds. The cephalothorax

is of a deep blue while the antennae, maxillipeds, and abdomen are

red. The species was described by Forbes from material found in

Shoshone Lake, and it also occurred in other lakes and ponds in the

_ vicinity of Yellowstone Park. In the Ward collection it appeared

_ in the material from Dead Lake, Mirror Lake, and Lake of Rocks,

_ all being in the Pike's Peak region.

___ As this species was figured only in connection with Forbes’s orig-

_ inal description and the later description of Schacht from Forbes’s

_ material, it has seemed wise to add diagnostic figures to this report.

_ The description of Forbes was very complete and it seems necessary

here only to add some things of minor importance. I did not find

the female abdomen asymmetrical, and in this my observations agree

Eis cous! in length to the rest of the cephalothorax. The last

cephalothoracic segment is armed laterally with two minute spines.

The first abdominal segment of the female is somewhat longer than

rest of the abdomen. It is dilated laterally and armed upon each

side with a sharp spine. These spines are at about the termination

of the first third of the segment. The distal margin of the segment

extended on the right side in a conical process which extends

beyond the second segment. The second segment is very short, and

148 HENRY B. WARD

is nearly covered by the first. The third segment is about one-third

the length of the first, and somewhat shorter than the furca.

The antennae reach slightly beyond the end of the furca. The

right antennae of the male is swollen anterior to the geniculating

joint. The antepenultimate segment bears upon its distal extremity

a hook-like process which is rather less than half the length of the

penultimate segment. In the female fifth foot, the spine of the first

basal segment is very pronounced. The second basal segment is

armed with the customary delicate hair. The first segment of the

exopodite is stout. The second segment is of the usual form, and

with the usual armature of the inner margin. The third segment is

not distinct, and is represented by two short spines. The

equals in length the first segment of the exopodite, and is armed at

the tip with two spines and with short hairs.

In the male fifth foot, the spines of the first basal segment are

very pronounced. The second basal segment of the exopodite is

trapezoidal in form, and its length exceeds its average width by about

one-half. The lateral hair is at about one-fourth its length from the

distal end. The first segment of the exopodite is about as broad as

long, and has its distal external angle somewhat produced. The

second segment of the exopodite is elongate, being more than three

times the length of the first. The lateral spine is situated at about

one-third the distance from the proximal end, is hook-shaped, and is

inserted at an angle with the plane of the segment, that is, it does not

lie in the same plane with the flat surface of the segment. The ter-

minal hook is elongate, falciform, with a regular curvature. The

endopodite is short, rather shorter than the first segment of the exo-

podite, and is somewhat triangular in from. The second basal seg-

ment of the left foot is similar in form to the corresponding segment

of the right foot and is about one-half as long. The lateral hair is

situated well towards the distal end. The first segment of the exo-

podite about equals the basal segment in length, but is more slender.

The second segment is short, armed with a terminal pad, a pad on its

inner face, and with two blunt spines near its distal end. The pads

are armed with short stiff hairs. The endopodite is very slender and

very nearly equals in length the two segments of the exopodite.

Average length of the male, 1.115 mm. Average length of the

female, 1.132 mm. Locality, Dead Lake, Pike’s Peak, associated

with D. magnus; also Lake Michigan, Lake of Rocks, and Mirror

BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES 149

Lake. Tt was especially abundant in the collections from Lake

_--—-—s'‘This species resembles D. signicauda in the process on the pos-

____ terior border of the first abdominal segment of the female. It differs

___ im so many points, however, that there seems to be no question of

___ its specific difference. The fifth foot of the female and the antennal

____ appendage of the male are as in signicauda. The proportions of the

____ female abdomen are quite different. The second abdominal seg-

ment in mudus is nearly covered while in signicauda it is nearly as

Jong as broad. The general proportions of the fifth foot of the male

____ are the same in both species. The first segment of the right exopo-

____ «dite in signicauda bears a prominent hyaline lamella on its inner

5 margin, which is entirely lacking in nudus. It is on account of this

peculiarity that the name is proposed. The lateral spine of the

second segment of the right exopodite is nearer the distal end in

7 while in nudus it is nearer the proximal end, is very

strongly curved, and does not lie in the same plane with the segment.

Report ON THE CLADOCERA By E. A, Brrce

The Cladocera in this collection are comparatively few in number

| and almost all of the species are the common widespread forms, such

as would be expected if any representatives of the group were

__-geeured. Not only are the species few in number but ordinarily

; there are but few individuals of each species. Daphnia, Eurycercus,

} and Chydorus are ordinarily abundant when present at all, but there

are only scanty representatives of the other species. I have, there-

fore, given a list of the species only, together with the description of

one form of Macrothrix, which apparently represents a new species.

Diaphanosoma leuchtenbergianum S. Fischer.

In the name of this species I follow Lilljeborg, Cladocera Sueciae.

Glen Alpine, pond near Susie Lake.

Holopedium gibberum Zaddach.

Glen Alpine, Susie Lake.

Daphnia pulex (De Geer).

A large semi-transparent form of this species was found, in num-

bers, from Dead Lake, Pike’s Peak.

Daphnia longispina O. F. Miller.

Some specimens of this species resembled the variety cevifrons;

others were typical.

;

4 :

150 HENRY B. WARD

Glen Alpine, Lily Lake (male and female), pond near Susie Lake

(July 1), Susie Lake (July 1); Pike’s Peak, Ribbon Lake, Mirror —

Lake.

Scapholeberis mucronata (O. F. Miiller).

Glen Alpine, Lily Lake.

Simocephalus serrulatus (Koch).

Glen Alpine, Lily Lake; Pike’s Peak, Lake of Rocks.

Ceriodaphnia reticulata (Jurine).

Glen Alpine, Grass Lake, Lake of the Woods.

Ceriodaphnia pulchella G. O. Sars.

Glen Alpine, Susie Lake; Pike’s Peak, Lake Michigan.

Bosmina longirostris (O. F. Miiller) P. E. Miller.

A very few specimens were somewhat doubtfully referred to this

species.

Pond near Grass Lake.

Macrothrix montana, sp. nov.

Length 0.45-0.55 mm. ; height 0.23-0.27 mm. The general form is

oval or round (Pl. XXV, fig. 2). The shell is thin and transparent.

Its ventral edge and the post-abdomen are often much overgrown by

algae and Vorticella. The dorsum of the head is evenly rounded to

the junction of head and body, where there is a deep indentation.

The shell of the head projects backward and overlies this depression

in two or three collar-like folds. No trace of spine or tooth has been

found on this ridge; thus differing from M. odontocephala Daday.

No fornix was seen, but as all the specimens are somewhat swollen

by the preservative, such a structure may be present. The carapace

is nearly round. The arched dorsal margin meets the ventral edge

in a shorply marked posterior angle. The usual spines are found on

the ventral margin. The antero-ventral angle is produced into a

rounded lobe. The surface of the carapace is marked by very faint

hexagonal meshes.

The macula nigra is about one-half the diameter of the eye. It is

situated near the point of the restrum and is nearly quadrangular in

outline. The eye is of moderate size, not very deeply pigmented.

The antennule is large and stout, with a sense hair near the base and

about six rows of hairs on the anterior face and three posterior rows.

The terminal sense hairs are of the regular Macrothrix type; two of

them being much longer than the others. The antennule in this

species, unlike that of M. odontocephala, shows no trace of being two-

al claws are very small, ct auch nape ee te

lis part of the post-abdomen. The larger anterior lobe is semi-

ee The setae

IE cle cs che choosy reprenented by, tao

_ seribed by Daday as M. odontocephala and M. bicornis; being nearer

» the former species. From this it differs in the absence of the

___ Spine, which gives the name to the species, in the shape of the ventral

eee we bend, and in the minute size of the terminal claws.

Susie Lake ; Kate Michigne, and Lake of Rocks.

lamellatus (O. F. Miiller).

~ Glen Alpine, Grass Lake, Susie Lake, Small Lake (July 1).

re vei cents

Grass Lake.

= Acroperus harpae Baird.

= Grass Lake, Lake of the Woods, Strawberry Lake.

_ Lake of the Woods, Strawberry Lake.

Pleuroxus procurvatus Birge.

Pike’s Peak, Lake Michigan.

‘Chydorus sphaericus (O. F. Miller).

Glen Alpine, Grass Lake, pond near Grass Lake, Lily Lake, Susie

___ Lake, pond near Susie Lake (July 1), Small Lake (July 1), pond

smear Half Moon Lake (cast shells), Lake of the Woods, Strawberry

__-~Polyphemus pediculus (Linné).

= Glen Alpine, Susie Lake, pond near Susie Lake (July 1).

ure atin, oe

. 7 a

152 HENRY B. WARD

LITERATURE CITED : ae

Bearnstey, A. E. ne

1902. Notes on Colorado Entomostraca. Trans. Amer. Mic. Soc., XXIII,

41-48. : ;

1902. Notes on Colorado Protozoa. Trans. Amer, Mic. Soc, XXIII,

49-59, 1 pl. a

Exxop, M. J.

1901. Limnological Investigations in Flathead Lake, Montana, and Vicin-

ity, July, 1899. Trans. Amer. Mic. Soc., XXII, 63-80, 9 pl.

Exrop, M. J. and Ricker, M.

1902. A New Hydra. Trans. Amer. Mic. Soc., XXIII, 257-258.

Forses, E. B.

1897. A Contribution to a Knowledge of North American Cyclopidae.

Bull. Ill. State Lab. Nat. Hist., V, 27-82, 13 pl.

Forses, S. A.

1893. 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, 207-258, 6 pl.

Fac, A., und VAvra, V.

1897. Untersuchungen iiber die Fauna der Gewasser Béhmens III. Un-

tersuchung zweier B6hmerwaldseen, des Schwarzen und des Teufels-

sees. Arch. natw. Landesdurchf. Béhmens, X, 3, 74 pp.

Guerne, J. pe, et Ricuarp, J.

188. Révision des Calanides d'eau douce. Mém. Soc. Zool. France, II,

53-181, 4 pl.

LeuMan, Harriet.

1903. Variations in Form and Size of Cyclops brevispinosus Herrick and

Cyclops americanus Marsh. Trans. Wis. Acad., XIV, 279-208, 1 pl.

Mur, Joun.

1900. Lake Tahoe in Winter. (Reprint of a letter published in the San

Francisco Bulletin in 1878). Sierra Club Bulletin, III, 119-126.

Mur, Joun.

1903. The Mountains of California. 381 pp. Many plates. The Cen-

tury Co., New York.

Pacxarp, A. S.

1883. A Monograph of the Phyllopod Crustacea of North America,

Remarks on the Order Phyllocanida. XII An. Rept. U. S. Geol. :

(Hayden) II, 295-s92, 39 pl.

Price, W. W.

1902. A Guide to the Lake Tahoe Region. An account of the scenery,

geology, natural history, the fishing, hunting and resorts. The infor-

mation gathered by the members of Camp Agassiz. 30 pp.

Russe, I. C.

1895. Lakes of North America. Boston. 125 pp., 23 pl.

Warp, H. B.

1903. Some Notes on Fish Food in the Lakes of the Sierras. Trans.

Amer. Fish. Soc., XXXII, 218-220.

PLATE XXV

esa

sav N3A3S

dew

153

Clements.

Long. and

Plate XXV

Plate XX

view is Eagle Lake, the lower Cascade Lake. Both show the

2. Macrothrix montana n. sp. See page 150.

Fig. 3. Macrothris montana n. sp., postabdomen,

_ BIOLOGICAL RECONNOISSANCE OF ELEVATED LAKES

XXIII).

Colorado,

and Colorado

The lines

ente 38° 50 N

By Wig. 1. Enlarged plat of territory immediately around Seven Lakes (C/.

on my visit to this lake July 1, 1903.

«i

ee. xxi

_ Gilmore Lake in early summer. The snow was only a little less extensive

OS ae

he "ee! i ie a

154 HENRY B. WARD

Plate XXVI

Valley of Seven Lakes from Mt. Garfield. The view is NNW with

Pike’s Peak at extreme right. 1, Lake of Rocks; 2, Ramona Lake; 3, Lake

Michigan; 4, Isoetes Lake; 5, Marsh Lake; 6, Ribbon Lake; 7, Mirror Lake.

Photographed by Dr. F. E. Clements in 1899.

Plate XXVII

Ribbon and Mirror lakes from the north. Mt. Garfield in the background.

Photographed by Dr. F. E. Clements in 1899.

Plate XXVIII

West shore of Mirror Lake with Garfield range in background, showing

reduction in water level in a single year. Compare Plate XXVI. Photo-

graphed in 1903 by Dr. F. E. Clements.

Plate XXIX

Dead Lake from the north with Old Baldy in background. Photographed

in 1899 by Dr. F. E. Clements.

Plate XXX

Fig. 1. Diaptomus nudus—abdomen of female X 165.

Fig. 2. Diaptomus nudus—fifth feet of male X 165.

Fig. 3. Diaptomus shoshone—terminal segments of right antenna of

male X 165.

Fig. 4. Diaptomus nudus—penultimate and antepenultimate segments of

right antenna of male X 290.

Fig. 5. Diaptomus nudus—fifth foot of female X 290.

Plate XXXI

Fig. 1. Diaptomus shoshone—abdomen of female X< 76.

Fig. 2. Diaptomus shoshone—fifth foot of female < 165.

Fig. 3. Diaptomus shoshone—fifth foot of male X 76.

NECROLOGY

RICHARD LEACH MADDOX

7 On heme May 11, 1902, there passed away at Portswood,

Southampton, England, Dr. Richard Leach Maddox, the pioneer of

_ photomicrography, and an honorary member of our Society, and by

his demise the scientific world is the poorer, losing as it does a steady

hard worker and accurate observer, as well as a most genial and

charming personality.

Richard Maddox was born at Bath in August, 1816. Of his early

days, very few details are on record, beyond the fact that he was

educated at a public school in Somersetshire. Then, having decided

on entering the profession of medicine, he became a student at Uni-

versity College, London, in 1837. Always delicate, he had, even

while a student, to suspend his work on account of the condition of

his health, and in 1839 he left England for a voyage around the

world. On his return in 1840 he resumed his studies, and obtained

the diploma of the Royal College of Surgeons of England two years

__ Iater. To this he added the license of the Society of Apothecaries

___ im 1843. As might have been expected from a man with such a

keen desire for work, and work for its own sake, we find him in

1844 pursuing his studies in Paris, which was then the centre of

medical research, attending chiefly the practice of the Hotel de la

Charité and the lectures of the late Dr. Donne. Dr. Maddox also de-

__ yoted a very large amount of his time to microscopy, and in this

connection it may be mentioned that he translated Dr. Dujardin’s

“ Manual ” at about the time that Quekett’s “ Treatise on the Micro-

scope” appeared, but as it was impossible to arrange for the use of

_ the beautiful plates illustrating the work, the translation was never

published. In 1847 he appears to have visited Smyrna, proceeding

afterwards to Constantinople, where for a time he practised his pro-

fession, and where he met Amelia, daughter of Benjamin Winn

Ford, Esq., of that city, whom he married in 1849. In 1850 he re-

155

156 RICHARD LEACH MADDOX

turned to England, and the following year took the degree of M.D.

of Aberdeen University. In 1852 he again settled in practice in

Constantinople, and during the latter part of the Crimean War held

the appointment of Civil Surgeon to the hospital at Scutari. His

health again causing him some anxiety, Dr. Maddox came back to

England, practising for a time at Islington, London, then at Ryde,

Isle of Wight, and finally settling at Woolston, near

in 1859, where he remained for fourteen years. In 1874 he left

Woolston to become resident physician to the late Duke of Mont-

rose, from whom he went to Sir William Watkins-Wynn, and then

to Lady Katherine Bannerman. His wife having died in 1871, Dr.

Maddox married in 1875, Agnes, daughter of George Sharp, Esq.,

of Newport, Isle of Wight (who survives him), and the same year

he again went abroad, first to Ajaccio, and afterwards to Bordighera

and Cornigliano, practising his profession amongst the English resi-

dents. Returning to England finally in 1879, he lived for some

years at Gunnersbury, but from 1886 onwards resided at Green-

bank, Portswood, Southampton, England, living in a most retired

manner, but keeping up his interest in everything relating to scientific

work, and constantly writing for various journals and papers in

England, France, and the United States; indeed, within a few

days of his death he contributed a letter to the papers, dealing with

the controversy anent the discovery of the “ Holy Shroud ” at Turin.

On the 10th of May, 1902, his old-standing complaint, aortic an-

eurysm, suddenly became worse, and on the following day he

breathed his last at the advanced age of eighty-five years. Dr. Mad-

dox was interred in the Southampton cemetery on May 15. A son

and a daughter by his first wife, and a son by his second wife, survive

him.

From this brief outline of a busy, restless life it is not easy to

see where, and when, Dr. Maddox secured the necessary time and

opportunity for the more strictly scientific research work which has

made his name famous, and it speaks volumes for his powers of

adaptability and of steady application that he was able to accomplish

so much under such unfavorable circumstances. As early as 1853,

he took up the study of photography, and in a contribution to

“ Photography,” February 11, 1892, he refers to this in the follow-

ing words: “ My first lens was bought about 1846, but active pro-

fessional duties prevented its being used until 1852; from that date

Ae)

RICHARD LEACH MADDOX 157

a8 an amateur, I have been interested in photography.”

a hy to microscopical work, just as he was one of the very

; grasp its potentialities for the reproduction of pictures of

a Preparations. In spite of his early failures in this

nt tio n he was sanguine of ultimate success and subsequently re-

ring to the subject he wrote: “ Still, I felt and trusted its day

mld come, and be of much assistance to the busy microscopist.”

His disheartening efforts in photomicrography only spurred him on

_ to further endeavors, and there is not the least doubt that the sub-

stitution of gelatine for collodion in the preparation of photographic

plates, resulting in the manufacture of dry plates, is the direct out-

come of his early photomicrographic failures. The first public rec-

_ ognition of his work in the portrayal of microscopical objects took

the form of a medal from the then “ Photographic Society of Lon-

don” in 1853. This was followed after a long interval by a medal

from the Council of the International Exhibition of Dublin (186s)

_ for a series of his photomicrographs, published by the late Jamies

_ Howe. In 1865 a reproduction of some of Dr. Maddox’s photographs

_ formed the frontispiece of Lionel Beale’s “ How to work with the

_ Microscope”—probably the first attempt in England to employ

_ photomicrographs as book-illustrations.

____ ‘The periodical attacks of ill-health to which he was subject, and

_ ¢ollodion emulsions of the “ wet ” photographic plate of that period,

_ made its effects painfully apparent, and, combined with the desire to

_ Obtain a less cumbersome and troublesome method of securing his

_ photograms of microscopical objects, caused Dr. Maddox to some-

__ what restrict the scope of his research work. The result of his exper-

_ iments became apparent in 1871, when he published in the “ British

_ Journal of Photography ” an account of the compounding of a prac-

_ ticable gelatino-bromide emulsion, and its employment as a “ dry”

photographic plate. The Royal Microscopical Society of England

immediately ized the value of his work by electing him

an honorary Fellow in 1871. Later on, he became a student of the

then infant science of bacteriology, and among other researches upon

_ which he was subsequently engaged, was one upon the micro-organ-

‘at kt

vie

158 RICHARD LEACH MADDOX

isms present in the air, in which he used a piece of apparatus of his

own invention, the “ aeroconiscope,” practically a multiple funnel set

up as a vane. The wind passing through this apparatus deposited

its contained organisms upon a thin coverglass prepared for its re-

ception by being coated with a layer of gelatine ; the organisms were

then cultivated and the results accompanied by many careful figures,

published in the current monthly Microscopical Journal. He gave

up much time also to microscopical drawing, and examples of his

skill may be found in the work of the late Dr. Parkes on “ Hygiene,”

and also in Dr. Nayler’s “ Skin Diseases.” Many of his colored

drawings, however, of Diatomaceae, when subjected to the action

of various reagents, and figures of the various yeasts in beer depos-

its, have not been published.

General public recognition of the value of Dr. Maddox’s work was,

as is too often the case in the world of science, delayed till late in life.

In 1885 he received the gold medal of the Inventions Exhibition, at

which he exhibited the earliest specimens of gelatine-bromide nega-

tives made, in 1871, and after this many honors reached him. The

Scott Legacy medal and premium from the Franklin Institute in

Philadelphia, U. S. A., was awarded him in 1889, whilst in the

autumn of 1891, as it was reported that he had lost heavily

through a defaulting trustee, a sum of between £500 and £600 was

raised for him in contributions from photographers in England,

France, Germany, and America, in recognition of the value of his

work. A gold medal from Antwerp, numerous diplomas, and finally

the Progress Medal of the Royal Photographic Society of England

(1901), were in turn conferred upon him.

Although Dr. Maddox’s experiments in emulsifying silver in gela-

tine do not entitle him, as many erroneously claim, to the credit of

having invented the gelatine dry-plate, there is not the least doubt that

he pointed the way for other workers. This is not the time to go into

the acrimonious discussions that have raged around this distin-

guished worker’s name—discussions which were rendered acri-

monious by the claims and counter-claims of others, for Dr. Maddox

himself seems to have troubled very little about the dispute. Indeed,

on his part there was throughout a conspicuous absence of assertive-

ness of virulence; he was one of that very high type of investigator

who works for the love of his subject and for the sake of truth,

without any ulterior motive, and certainly with no thought of

| he »-:

=) io

hr he mt eat eit of is hare Ba 2

BUSHROD WASHINGTON JAMES, A.M., M.D., LL.D.

For several successive generations the James family, from which

Dr. James was descended, has resided in America. His paternal

great-great-great-grandfather, David James, came from Wales, ac-

companying William Penn, and located in Radnor Township, Mont-

gomery Co., Pa. He purchased an extensive tract of land where

Bryn Mawr and Rosemont are now located. Dr. James’ grandfather,

Dr. Isaac James, was a physician, who lived to the advanced age of

ninety-seven. One of his uncles, Dr. Thomas P. James, of Cam-

bridge, Mass., was an eminent botanist and bryologist and a great

authority on mosses. The Doctor’s father was David James, M.D.,

a graduate of Jefferson Medical College, who was one of the pioneers

of homoeopathy in Philadelphia.

Dr. Bushrod Washington James was born in the city of Phila-

delphia, August 25, 1836. His father gave him a careful and liberal

education. In 1857 he graduated from the Homoeopathic Medical

College of Pennsylvania, receiving therefrom the degree of M.D.

and H.M.D. The faculty on his graduation placed him in charge

of the large dispensary connected with the college. Subsequently

he originated a surgical infirmary and mainly supported it for years

by his own efforts and energy and that of two of his friends. He

located at the northeast corner of 19th and Wallace streets in Phila-

delphia and has ever since resided in that section of the city. His

connections with various societies, medical, scientific, and literary,

have been and still are numerous, and he has also been connected

with various medical institutions, serving in one as professor. For

seven years he was attending physician to the Northern Home for

Friendless Children. He here obtained a very valuable experience

in diseases of the eye, having treated several hundred cases of con-

tagious ophthalmia without loss of vision in any case. He has been

for seventeen years eye clinician at the Children’s Homoeopathic

Hospital.

In 1867, Dr. James visited Paris as a national delegate from the

American Institute of Homoeopathy to the French Homoeopathic

Medical Congress, to which he presented a medical essay. In 1881 he 4

160

BUSHROD WASHINGTON JAMES 161

Siiltet- te Totctcational Homoeopathic Medical Convention, held

in London, before which he read a paper on iritis. He also attended

the World’s Medical Congress, London, held the same year. During

_ the Centennial year, 1876, he was a member of, read a paper before,

_ and took other active part in the proceedings of the first International

Homoeopathic Convention, which was held in Philadelphia. In 1873

___ he was President of the Pennsylvania State Homoeopathic Medical

_ Society, and in 1883, at Niagara, he was President of the National

____ Society of the American Institute of Homoeopathy. For seventeen

____ years he was Surgical Editor and Sanitary Science Editor of the

___ then American Observer of Detroit. For several years he was Presi-

____ dent of the American Literary Union and also of the Hahnemann

y _ Club of Philadelphia. He was for years President of the Children’s

__ Homoeopathic Hospital of Philadelphia, and was previously Presi-

_ dent of its Medical Board. He was one of the consulting physicians

___ im the Hahnemann Hospital of Philadelphia, a member of the ad-

_____visory board of the Hahnemann Medical College, and for twenty-

__ five years also one of the trustees of the Spring Garden Institute.

At one time he filled for several years the chair of physiology, sani-

tary science and climatology in the New York Medical College for

_ Women of the University of New York. Professor James was a

member of the American Public Health Association, of the Amer-

ican Association for the Advancement of Science, of the American

Microscopical Society and of the Senate of Seniors of the American.

“Institute of Homoeopathy, and Vice-President of the Pennsylvania

_ Fish and Game Protective Association, and a member of the Amer-

ican Fisheries Association for the care of the food-fishing interests

in the United States.

During the Civil War he was a member of the Christian Commis-

sion, and was a volunteer surgeon on the battle-fields of Antietam

and Gettysburg, and a surgeon in one of the army hospitals of Phila-

delphia. In 1878 he was one of the Commission of Eleven appointed

by the American Institute of Homoeopathy to investigate the yellow

fever epidemic of that year and collect statistics of its treatment and

mortality. He also belongs to several bodies of a general character,

including the Masonic fraternity, Knights Templar, Masonic Vet-

erans, the Union League, the Horticultural Society, the Franklin

Institute, Pennsylvania Historical Society, Sons of the Revolution,

the Academy of Natural Sciences and the Authors’ Guild of America.

162 BUSHROD WASHINGTON JAMES

As a writer he achieved some distinction. From 1880 to 1888 he

was business manager of the Hahnemannian Monthly and did much

to raise the literary and general character and increase the circula-

tion and value of that periodical. Dr. James was the author of

“ Alaskana, or Legends of Alaska,” now in its third edition. This

is written in the Finnish style of Longfellow’s Hiawatha. It is a beau-

tiful literary production and has many graphic descriptions of the

life of people of Alaska and the sublime scenery of that region. He

has also written several books and pamphlets on that region, being

an ardent believer in its great future. Dr. James visited Alaska and

all sections of the United States and British America, and Newfound-

land. He was a great traveller, visiting many foreign places, espe-

cially in Mexico, Europe, Asia, and Africa. Another of his produc-

tions, entitled “‘ American Resorts and Climates,” is a scientific de-

scription of the resorts of this country. The “ Dawn of a New Era

in America,” touches upon some of the live political issues of the

day. As an author, he combined the accurate conceptions of science

with the charms of poetry and philosophy. As a physician, his rare

attainments, long years of experience and connection with the prin-

cipal medical societies of the age made him justly prominent in his

profession.

He was stricken with pneumonia a year ago and recovered suffi-

ciently to return home, but never regained his strength, and after

a long illness he died January 7, 1903, in the sixty-seventh year of

his age. He was never married. In him this society has lost an active

and efficient member and the state a valuable and much honored

citizen.

OSCAR C. FOX

-_—

—

OSCAR C. FOX

Major Oscar C. Fox was born in Pitcher, N. Y., of English and

ene ee ae

arrict Amanda, born Chapman. His grandfather, Hubbard Fox,

erved in the First Connecticut line during the Revolutionary War, —

d the boy Oscar began working in his father’s flour and saw mills.

le was educated in Pitcher Springs Academy, Chenango County,

id McGrawville or Central College, Cortland County.

L » many prominent and successful men he taught school in early

ffe, and from 1856 to 1860 was principal of Nelson Academy in

a >. In 1861 he raised a company of soldiers in his native county

_ of Chenango and entered the 76th New York Vols. with the rank

Captain. They were immediately sent to the front and after tak-

_ ing part in several battles, on August 28, 1862, he was dangerously

wounded at the battle of Gainesville, Va., receiving a shot through

the lungs, the ball remaining in his body during the rest of his life.

account of disability December 22, 1862, with the rank of brevet Ma-

_ jor. Three years after he received this wound, and at the exact hour

— eat he threw out

; of cotton the bullet had carried into his body from the

Hiiidiag of bis vest, and from that time on his health gradually and

ee “eernet

From 1864 to 1870 Mr. Fox served as a clerk in the office of the

Commissary General of Subsistence at Washington, a position he

Diteed to cater the Patent Oftce, in which he obtained as the re-

_ sult of competitive examination, in July, 1873, the position of Prin-

sal Examiner. He was placed in charge of one division, which

sludes agricultural machinery and tools chiefly, and occupied this

»sition until his death, which took place June 6, 1902.

_ Major Fox had a strong natural inclination for scientific work,

ite living a: Lindss, tn the echerbe of Weshingion, cum

| structed a small reflecting telescope, polishing the mirror himself.

planned a much larger one, and partially made it, but change of

leon and fang hath prevented competion. In May, 1876,

163

164 OSCAR C. FOX

he conceived the idea of introducing compressed air into the her-

metically sealed tube of a telescope to prevent flexure of the objec-

tive by gravity. He also contrived a novel uniform motion mechan-

ism for rotary fluid parabolic reflectors of any possible aperture for __

zenith observations. Besides these inventions he made several im-

provements in other lines of mechanics, his mind being constantly

active and interested in scientific work. He was a member of the

G. A. R., of the Union Veteran Legion, of the American Associa-

tion for the Advancement of Science, of the Washington Micro-

scopical Society and of the American Microscopical Society, having _

joined the latter in 1892. iy

In person he was tall and large-framed, with a gentle manner that

seemed almost a contrast to a somewhat imposing personality. He

was married on September 11, 1866, to Abbie Galt, of Delaware .

County, N. Y., who, with one daughter, survives him. j

Wa. H. SEAMAN |

oy ee ee

on ge Ae oad | ‘

J. C. MILLEN

r. J. C. Millen was born in Philadelphia, Penn., July 5, 186s.

was educated in the Philadelphia High School and at the age

entered the Baldwin Locomotive Works as draughtsman.

adv ted so rapidly that at the age of eighteen he was one of

hief draughtsmen and was placed in charge of a number of men.

n early age he was deeply interested in medicine and spent every

ai minute in its study. To enable him to continue his studies

: s line he started, in 1885, to manufacture a roll blue print paper

Co purposes. All blue print paper on the market at this

m e was hand-coated and very imperfect. He introduced specially

si machinery of his own invention whereby he was able to

ans ad one which bad great eezing

eS, a point heretofore unattainable in this process. He started

nally with an output of about one hundred yards of prepared

er per dey, end by 1890 was contng and shipping about fv

es of paper per day. About 1890 he conceived the idea of pro-

ee Sever seni Bev ie enon:

, the paper which he manufactured for architects and

engineer itil tens cuaiie'o tecture to vendet the fine detail and

_ half-tones necessary for the photographic process. With this idea

in view he introduced “ French Satin, Jr.,” which has since become

th es Eemcemaphic bine peint paper. At first his output

1 to about one hundred packages per week and it was con-

# pe Sater canatl cide fenue of his business. Today, the demand

a Ee oo eemnmeee ove ares oper hes grows. to exh SS

t that practically his entire plant is devoted to its manufacture,

ar d the production represents practically all of the photographic blue

a paper used in America.

In the meantime, he had entered the Hahnemann Homeopathic

Medical College in Philadelphia and graduated from this institution

4 11887. He was able to adjust his business so that it required only

a small portion of his attention each day and immediately began the

“practice of medicine in Philadelphia, establishing a large and lucra-

ti a =e ee He was a deep student of chemistry

= 165

166 J. C. MILLEN

and also a fine microscopist. He was connected with the Homeo-

pathic Hospital as well as the Children’s Homeopathic Hospital and

was noted for his untiring energy. He was a man of great magnet-

ism and his skill and ready sympathy made him a favorite with his

patients as well as his associates. Being an enthusiastic amateur

photographer, he made photographs of all his interesting cases be-

fore and during the different stages of treatment and his collection

is large and interesting.

In 1897, owing to overwork, his health failed, and he was advised

by his physicians to give up medicine and remove to Colorado. He

took up his residence in Denver, and immediately removed his manu-

facturing plant to that city. He devoted his entire time to adding

new photographic specialties to his already well-established business,

and today his developers, combined toning and fixing powder, chro-

mium fixing salt, and library paste are without peer.

In 1900, thinking that he had fully recovered from his former

illness, he again resumed medicine in Denver, and was rapidly es-

tablishing a good practice, when again his health failed, and from

this attack he did not recover. His death occurred April 26, 1901.

He was a member of the American Microscopical Society, the

Homeopathic Medical Society of Philadelphia, and the A. R. Thomas

Club.

PROCEEDINGS

MINUTES OF THE ANNUAL MEETING

.. HELD AT

_ WINONA LAKE, INDIANA, JULY 27, 28 AND 29, 1903

addition of life members, with conditions attached thereto.

The report of the Treasurer was formally postponed till the close

of the fiscal year, which was fixed for October 3, and Messrs. F. W.

Kuehne and Rudolph Siemon were appointed auditors.

The report of the Custodian was read and Drs. J. S. Foote and B.

__ E. Bush were appointed an auditing committee.

__._ The Secretary reported for the Executive Committee that an invi-

tation had been received from Professor Eigenmann to visit the

laboratory of the University of Indiana Biological Station, and rec-

a its acceptance. On motion of Mr. J. C. Smith the same

was accepted and the Society adjourned.

Pie

Eithks Society was called to order in the laboratory of the Biological

sata ea rte eo tn ma

papers, as follows:

_ Dr. V. A. Latham: Structure of the Dental Pulp, with Photo-

_ graphic Demonstrations ; discussed by Dr. J. S. Foote.

Dr. J. S. Foote: The Tube Plan of Structure of the Animal Body ;

“Guensed by De. HB. Ward and Profewor EA. Dire

Dr. C. H. Eigenmann: Ontogenctic Degeneration of the Optical

_ Organs of the Cuban Blind Fishes; discussed by several members

eres ates i Ss Rosy ethene

167

168 PROCEEDINGS OF THE

THIRD SESSION

The Society convened in the auditorium at The Inn at 7 p.m., and

listened first to an address of welcome by Dr. S. C. Dickey, Presi-

dent of the Winona Association, which was responded to by the __

President of the Society, Professor E. A. Birge. The latter then

delivered his annual address on The Biological Significance of the __

Thermocline. aa

After a general discussion of the topic presented, the Society again

adjourned, on invitation of the Winona Assembly board of mana-

gers to attend a lecture by Mr. Ernest Thompson Seton.

FOURTH SESSION ci

The Society was called to order at 10:30 A.M., Thursday, July 28,

in the Biological Station laboratory, and the following papers were

Professor T. J. Burrill: River Pollution and Purification; dis-

cussed by Professors Birge, Caldwell, and others. a

Mr. J. C. Smith: The Parasite of Yellow Fever; discussed by 1.

Professors E. A. Birge, H. B. Ward, and T. J. Burrill, and Dr. V.

A. Latham. ae

Professor B, L. Seawell: Some Observations on the Plankton of

a Small Lake under Storm-flood Conditions ; discussed by Professors

E. A. Birge, O. W. Caldwell, Charles Fordyce, and H. B. Ward.

A nominating committee, consisting of Professor T. J. Burrill,

Dr. V. A. Latham, Professor H. B. Ward, Dr. J. S. Foote, and Mr.

J. C. Smith, was unanimously elected. The Secretary reported the —

loss by death of Drs. M. L. Holbrook, B. W. James, J. C. Millen, 4

O. C. Fox, regular members, and Dr. R. L. Maddox, honorary mem- %

ber, and was instructed to secure biographical sketches for the next — '

volume. The Society adjourned at noon. a

FIFTH SESSION q

The members came together once more at 2:15 P.M., and the tol: 4

lowing papers were considered: a

Professor R. H. Wolcott: Studies on the Lakes of the Sandhill. u

Region of Nebraska; discussed by Professors Charles ros E ;

A. Birge, C. H. mcoeN and others. ;

Elevated tates in ‘tis Sierras : discussed by many members, =

mally, during the examination of numerous photographs used om 4

lustrate the paper.

"Professor M. J. Elrod: The Ricker Pump in Limnological Investi-

_ Dr. D.C. Hilton : Preliminary Report on a Specimen of Bothrio-

The Society then adjourned.

In the evening, Professor and Mrs. C. H. Eigenmann tendered a

__feception to the members at their summer home, which was beauti-

fully decorated in honor of the Society. The occasion was most en-

____ joyable and the guests lingered until a late hour in discussion. The

presence of the staff from the Biological Station added to the en-

a oe ovoniee

SIXTH SESSION

‘Friday, July 29, the entire day was occupied by an excursion to

e Turkey Lake, under the leadership of Professor Eigenmann. This

afforded opportunities of examining other lakes en route, of collect-

__ ing in them, and of enjoying a trip about Turkey Lake itself in a

general survey of the biological conditions. On board the steamer,

_ which was chartered by Professor Eigenmann for the exclusive use

of the Society, a business session was held, during which the amend-

ments to the Constitution, printed on pages 175 and 176 of Volume

_ XXIV, were considered and adopted.

On recommendation of the nominating committee the following

persons were unanimously elected to serve as officers for the ensu-

ing year

President, Professor T. J. Burrill, Urbana, Ill.

170 PROCEEDINGS OF THE

First Vice-President, Professor H. A. Weber, Columbus, O.

Second Vice-President, Dr. F. W. Kiihne, Fort Wayne, Ind.

Assistant Secretary, Dr. R. H. Wolcott, University of Nebraska,

Lincoln, Neb.

Elective members of Executive Committee: Mr. Chas. F. Cox,

New York City; Mr. L. B. Elliott, Rochester, N. Y.; Professor J.

M. Stedman, Columbia, Mo.

The thanks of the Society were voted to the retiring President,

Professor Birge, to the directors of the Winona Assembly and of

the Indiana University Biological Station, for many courtesies and

privileges extended to the Society, and also to both Professor and

Mrs. Eigenmann for their generous hospitality to those in attend-

ance. The Society then adjourned subject to the call of the Execu-

tive Committee. Henry B. Warp,

Secretary.

MID-WINTER MEETING, ST. LOUIS, MO., DECEMBER

28 AND 29, 1903

Pursuant to the call of the Executive Committee the Society con-

vened in Room 109 of the Central High School, St. Louis, Mo.,

Tuesday, December 28, 1903, atQ A.M. By the courtesy of the Local

Committee an adjoining room was also set aside and furnished for

social purposes while a supply of microscopes and a projection lantern

was provided for demonstrations. ;

Owing to the number of other meetings in progress at the same

time, and to the small number of members who went to St. Louis,

the sessions were very informal and somewhat irregular. The fol-

lowing papers were presented and discussed by members in general

in connection with the microscopical demonstrations appertaining

thereto. The work was of peculiar interest and importance and de-

served a much larger audience than was assembled.

Dr. H. M. Whelpley: North American Flint Implements of Micro-

scopical Interest (with demonstrations). 4

Professor F, L. Landacre: Fresh-water Protozoa of Ohio, with

Bibliography.

Dr. G. C, Crandall: Plasmodium malariae (with demonstrations).

Dr. J. H. Stebbins: Haematozoa of the Turtle. me

Dr. Henry B. Ward: Some Notes on the Morphology of Trypano-

somes (with demonstrations).

AMERICAN MICROSCOPICAL SOCIETY 17!

Dr. Carl Fisch: Amoeba dysenteriae (with demonstrations).

Dr. H. M. Whelpley: A Compound Microscope of 1750, and an

‘Objective of Peculiar Construction.

Dr. H. M. Whelpley: Notes on Technic in Mounting and Demon-

_ strating Microscopic Objects.

ar eee oceans (by invitation): A Municipal Microscopical

| Dr. Charles E. Bessey: The Structure and Classification of the

a Protophyta with a Revision of the Families and a Rearrangement

a . J. Burrill: Aerial Disinfection.

the Buffalo Society the appreciation of this Society for the courtesy.

A vote of thanks was unanimously adopted for the courtesies re-

ceived in St. Louis, especially from the general Local Committee for

all affiliated societies, from the committee of the St. Louis Micro-

_ Wednesday noon a luncheon was tendered to members of the

Society and their wives by the St. Louis Microscopical Society, under

the direction of a committee consisting of its President, Dr. G. C.

Crandall, and Dr. H. M. Whelpley. The tables were beautifully

decorated and all details were admirably carried out, so that the occa-

sion was thoroughly enjoyed by all present. The Society recorded

an appropriate vote of thanks to the gentlemen and to the St. Louis

Microscopical Society for the generous hospitality.

Henry B. Warp,

Secretary.

172 PROCEEDINGS OF THE

CUSTODIAN’S REPORT FOR YEAR ENDING joLy

23, 1903

SPENCER-TOLLES FUND

Reported at Pittsburgh Meeting. . bake Ge bs. eb Deen aeean

ANNUAL GnowTH

BQO os'c.cunsvacnvudhic ved ba tedaiehsed anaes niaeseD

BODE. 20 voce cesey du dacsadhs Lidanebecbeienaands ebbnueane

CONTRIBUTORS TO SPENCER-TOLLES FUND GIVING $50 OR. oF

OVER (CONSTITUTION, ARTICLE VII) | ae

John Aspinwall Robert Brown

Troy Scientific Association A

Macnus Priaum, Custodian, =

Wruvona Lake, Inn. J

, . ' 4 — rr a

a i Yi , c - .- : : ‘ “Ser

; rr ¥ $ ae f N, aes.» ~ nd ee wih oe =-) Shot So

; ; ee Ve Bs . - ee (oe hola ey ee ee ee an

Ets e i , te Geno a au ae, nate Leen } r ,

Co 5 . aa . ne (+S ie tee oem Re Tin ms a * ‘

BEERSRBRSESE

aes

with vowhioch ‘had Sound the elade 4; anlcae elie aia aa

J. S. Foore,

B. E. Busa,

Auditing Committee.

AMERICAN MICROSCOPICAL SOCIETY 173

TREASURER’S REPORT

in NOVEMBER 24, 1902, TO FEBRUARY 30, 1904

DR.

Wud ob eGve eben ci babanevtie ssedecte!. GS

URGE

ial

XXIV

Tes MEME A Ssh beans vascesSas4< Mae Sn

sig?

Px mene

>a : Ties

a By Foe Bemeeetrss sseyriesyiahss Ree, Fe

Stationery and Printing, Treasurer conn 2 75

By ace on Vt RR backs 17 00

CONSTITUTION

mS. Arricie I

‘Socrery. Its object shall be the encouragement of microscopical

____ tee and in conjunction with a permanent committee to be called the

____ Spencer-Tolles Fund Committee, and to make a full and specific an-

nual report of the condition of all the property, funds, and effects

F in his charge; and of the Secretary to edit and publish the Trans-

actions of the Society.

I 76 CONSTITUTION AND BY-LAWS

Articte VI

It shall be the duty of the Executive Committee to fix the time and

place of meeting and manage the general affairs of the Society.

ArticLte VII

The initiation fee shall be $3, and the dues shall be $2 annually,

payable in advance. But any person duly elected may upon payment

of $50 at one time, or in instalments within the same year, become

a life member entitled to all the privileges of membership, but ex-

empt from further dues and fees. All life membership fees shall

bcome part of the Spencer-Tolles Fund, but during the life of such

member his dues shall be paid out of the income of said fund. A

list of all life-members and of all persons or bodies who have made

donations to the Spencer-Tolles Fund in sums of $50 or over, shall

be printed in every issue of the Transactions. The income of said

fund shall be used exclusively for the encouragement and support of

original investigations within the scope and purpose of this Society.

The principal of the fund shall be kept inviolate.

ArticLe VIII

The election of officers shall be by ballot.

Articte IX

Amendments to the Constitution may be made by a two-thirds

vote of all members present at any annual meeting, after having

been proposed at the preceding annual meeting.

BY-LAWS

ArticLe I

The Executive Committee shall, before the close of the annual

meeting for which they are elected, examine the papers presented

and decide upon their publication or otherwise dispose of them.

All papers accepted for publication must be completed by the

authors and placed in the hands of the Secretary by October 1st

succeeding the meeting.

Articte II

The Secretary shall edit and publish the papers accepted, with the

necessary illustrations.

ArticLte IV

“Be dropped from the roll, with the privilege of reinstatement at any

Tie sejrmenk af afl arrears. The Transactions shall not be sent

ARTICLE V

Ret iciacs cf ciicoe dai be teld cn the morning of Gas

Sol the sand mecting. Their term of office shall commence at

_ the close of the meeting at which they are elected, and shall con-

; Articite VI

Candidates for office shall be nominated by a committee of five

Articre VII

All resolutions relating to the business of the Society

shall be referred for consideration to the Executive Committee

Articie VIII

Members of this Society shall have the privilege of enrolling mem-

bers of their families (except men over twenty-one years of age)

for any meeting upon payment of one-half the annual subscrip-

tion ($1).

| Arricite IX

There shell be o standing committes known as the Spencer-Tolles

Fund Committee to take general charge of the fund and to recom-

178 CONSTITUTION AND BY-LAWS

mend annually what part of the income shall be expended for the

encouragement of research, but the apportionment of the sum thus 3

set apart shall be made by the Executive Committee.

The Spencer-Tolles Fund Committee shall also have general

charge of the expenditure of such money as may be apportioned,

under the conditions laid down by the Society for its use.

The Custodian shall be an ex-officio member of this committee. __

ARTICLE X

The Executive Committee shall have the power annually to ap-

point two members to represent the Society on the Council of the

American Association for the Advancement of Science, in accord-

ance with the regulations of the latter organization. 7

Revised by the Society, July, 1903.

LIST OF MEMBERS

LIFE MEMBER

ees suneeseeeseesss+Observatory Place, New Haven, Conn.

HONORARY MEMBERS

" Hupsox, C. T, AM, LLD., F.R.MLS. (died October 24, 1903),

, Hillside, Clarence Road, Shanklin, Isle of Wight, England

‘Surrm, Haunzox L, LLD... ..606 W. 115th St, New York City

‘Wann, R. Harstep, A.M, MD. FRMS.........53 Fourth St., Troy, N. Y.

Encra Scuwantz, Ph.D. Myers, Perry C.

Watson, Wa. F., A.M.

coat gna Ww, ee

.. University of Nebraska, Lincoln, Neb.

179

180 AMERICAN MICROSCOPICAL SOCIETY

Barnsratuer, James, M.D., 'o1......Sixth Ave. and Walnut St, Dayton, Ky. | 7

Bartietr, Cuartes Josern, M.D., '96..96 Sherman Ave., New Haven, Conn.

Bauscn, Epwarb, "78. ......00esceeeees 7 N. St. Paul St., Rochester, N. Y.

Ravcer, Himwny, "OSs 5s socccsceccctouthacuse . Rochester, N. Y.

Bavece, Wrerzam, GB. cccicscsvenneverchaavea St. Paul St, Rochester, N. Y¥.

Beat, Pror. James Hartiey, '96... Scio College, Scio, Ohio —

Bet, Avsert T., B.S., A.M., ’03,

Nebraska Wesleyan University, University Place, Neb.

Bewt, Crarx, Eso., LL.D., ’o2. . ..39 Broadway, New York City

Bennett, Henry C., ’93.. , Bout, Fiat, 3692 Broadway, New York e)

Bunwea, J. Heqaen, QO. i.sccveccpsntesbave 421 W. William St., Decatur, Ill.

Bessey, Pror. CHARLES cagslagh Ph.D., LL.D., ’98..............Lincoln, Neb.

Beyer, Pror. Geo. E., 99.. .- Tulane University, New Orleans, La.

Birce, Pror. E. A., S.D., LLD., ‘t99, - . Univ. of Wisconsin, Madison, Wis.

Biscor, Pror. THomas D., ’o1.. . 404 Front St., Marietta, Ohio

Bieme, A. M., M.D., ’81.. Obie State University, Columbus, Ohio

Bopvrng, Pror. DonaLpson, 106. . ...303 W. Main St., Crawfordsville, Ind.

Boorn, Mary A., her ge ds Rates Dartmouth St., Springfield, Mass.

Boyer, C. S., A.M, '92...........+.++++.3223 Clifford St, Philadelphia, Pa.

Brepin, Geo. S., ’96.. oc cece es sees ccse0crc sien W nan! ant

Bromiey, Rosert ions, MD. ‘tgs... -+see++..Washington St. Sonora, Cal.

Brown, N. How ann, ’or.. ear daa S. Tenth St., Philadelphia, Pa.

Brunpace, A. H., M.D., Hesse ee O73 Bushwick Ave., Brooklyn, N. Y.

Butt, James Epcar, Esq., ’92................141 Broadway, New York City

Burry, Pror. T. J., Ph.D., '78.......2200:: .....Urbana, Til.

Burt, Pror. Epwarp A., Ph.D., wes: 46 + Middlebury ‘Colieas, Middlebury, Vt.

Bus, Miss Bertna E., M.D., ’95...........-.-808 Morse Ave., Chicago, Til.

Brisa, D. BE, “08. .<<cxcvesasdutesneeeaee 114 W. Second St., Oil City, Pa.

Catpwett, Oris W., Ph.D., ’03...............-State Normal, Charleston, Il.

Carpenter, THos. B., M.D., ’99.............-533 Franklin St., Buffalo, N. Y.

Carter, Joun E., ’86..Knox and Coulter Sts., Germantown, Philadelphia, Pa.

Crarx, GayLorp P., M.D., ’96..........619 W. Genesee St., Syracuse, N. Y.

Crarx, Georce Epw., M.D., ’96...........- Skaneateles, Onondaga Co., N. Y.

Ciements, Freveric E., A.M., Ph.D., ’98...Univ. of Nebraska, Lincoln, Neb.

Crements, Mrs. Eprrn Scuwartz, A.M., Ph.D., ’03,

Univ. of Nebraska, Lincoln, Neb.

Coase, A. J. QB. és a8 . University of Nebraska, Lincoln, Neb.

Cocks, Pror. ReoiwaLp Ss. "99... --MeDonogh High School, New Orleans, La.

Corrin, Rozert, ’0o. .. bebbenkh ..Bedford City, Bedford Co., Va.

Coucn, Francis G., 86,

Kalish Pharmacy, 100 E. Twenty-third St., New York City

Cox, Cuas. F., F.R.S.M., ’85.........-.Grand Central Station, New York City

Caave, Tweets, i.vs swubdcseeaswecs 1013 Sherbrooke St., Montreal, Canada

Cranvat, Geo. C., B.S., M.D., ’03............4287 Olive St. St. Louis, Mo.

_ LIST OF MEMBERS 181

S. Hopart, Ph.G., '95 907 Seventh St., Buffalo, N. Y.

“e . .-Box 1033, Rochester, N. Y.

Henry B., B.S., A.M., ‘03 ..-State Normal, Peru, Neb.

Exumso, M.D., ‘o2 ++eeeeeee-5an Jése, Costa Rica

Mee IB wi on caesdic 630 Atwater St., Bloomington, Ind.

City

Re a sas sad dus ddd id dped oan

Pror. B., M.D., '96..........118 York St. New Haven, Conn.

Vdcapscdendopnucs oc eccl UGE Fee, 10> ou a

Fiscn, Cast, M.D., Ph.D., '03 es seeees+s+3212 Pine St., St. Louis, Mo.

EE Wb adsbesensb abbesavobusendd 646 Broadway, Milwaukee, Wis.

Cuas. E. M., 'o3 ...259 S. Clinton St., Chicago, Ill.

ae OB. cdvvades Zeiss Optical Works, Jena, Germany

James M., M.D., 'o1.............. The Portland,” Washington, D. C.

. S., MD., 'o1................202 S. Thirty-first Ave. Omaha, Neb.

Fospyce, Cuames, B.S., A.M. Ph.D., 'o8,

Nebraska Wesleyan University, University Place, Neb.

C., M.D., 99... .. 20. 400ee04+4+-342 Ohio Ave., Columbus, Ohio

mas. G., M.D., F.R.M.S., 'B1..........Reliance Bldg., Chicago, IIL

. Srwonw H., B.S., "B2............Cornell University, Ithaca, N. Y.

Susanna Puewrs, 87..............4 South Ave, Ithaca, N. Y.

Gattoway, Prov. T. W., Ot... ....-.000+ MeMillen University, Decatur, Ill.

I, UL, ci non de aussie ec ehddenemebsleulacaes Chevy Chase, Md.

Guuerr, Joux, M.D., 'o2 ce veeeeese Sparta, Kent Co., Mich.

Miss Geerevoe A., B.A., 'o3......27 Charlotte Ave. Detroit, Mich.

S., ‘o2 <sseeeeeset§20 Eighth Ave. East, Oakland, Cal.

se eiee IR. Es As cae wane auinv oss ane High School, Clinton, Iowa

Gross korr, Eanser CE WSs ccd den éde twaudcas a Cee:

rae ire eo

‘ f

182 AMERICAN MICROSCOPICAL SOCIETY

FAAS D. By MLD. "WS enciic's sons shsccssassstquaseraen Liberty Center, Ohio ve

Hatt, Victor S., ‘or. . ..1gtt Webster St, San Francisco, Cal.

Hanaman, C. E, FRMS, “M99. bbe pebbose State and Second Sts., Troy, N.Y.

Hawxinson, T. L., ’03.. Seles ..State Normal, Charleston, Til

Hatrie.p, Joun J. B., PENS , 333 N ‘Aveda Ave., Indianapolis, . :

Heatzier, Artuur A., M.D., ‘6. . Cre ucamete 508 Altman Bldg., Kansas City, Mo.

Hextzoc, Maxrmmian, M.D., bpitiee: abies E. Chicago Ave. Chicago, Il

Hicatns, F. W., M.D., ’98.. seeeeeeeseees 20 Court St, Cortland N.Y. —

Hi, Hersert M., Ph.D., ’87.. seseeeseeee24 High St, Buffalo, N.Y.

Hitton, Davin Ciark, A.M., MD., OE So wadeaweanen 1116 O St., Lincoln, Neb. ‘

Hoses, B..20,. OB ics ac s.ccv tien voguwdele cupewesceunpeneee Jefferson City,Mo.

Horrman, Jos. H., M.D., '96.. -111 Steuben St., Pittsburg, Pa.

Hous, Frepertcx S., Ph.D., '90.. _ Yale Medical School, New Haven, Conn. ‘q

Homes, A. M., M.D., bel - . .205 Jackson Block, Denver, Colo.

Hoskins, WM., ’79.....-- ...Room 54, 81 S. Clark St, Chicago, Ill. ‘a

Howe, W. T. H., PhD., NOD. oven ve nothoacunts shnsmtaee ..-- Evansville Ind.

How anp, Henry R., A.M., 98...........--.367 Seventh St, Buffalo, N.Y.

Humpurey, Pror. O. D., Ph.D., ’95....State Normal School, Jamaica, N. Y.

Bvast, FDR. Gi Sein ccs byiewkord 69 Burling Lane, New Rochelle, N. Y.

Ives, Frepertc E., ’o2...............-550 W. Twenty-fifth St, New York City

Jacxson, Danret Dana, B.S., ’99........++941 President St., Brooklyn, N. Y.

James, Franx L., Ph.D., M.D., ’82.. ..514 Century Bldg., St. Louis, Mo.

James, Geo. W., '92.. ; .-108 Lake St. Chicago, TIL

Jounson, Frank S., MD., “FRMS, Ign. saga Prairie Ave., Chicago, Ill.

Jommeon, Wr: Di MBps baba da bedi vc beccce'vs channel Batavia, N. Y.

Jones, Mrs. Mary A. Drxon, M.D., F.R.MLS., ’98, a

249 E. pgpeeP ess St., New York City a

Jonmaw, Cmamcey, 66.5 cadcndadeas seuss ..1060 Twelfth St. Boulder, Cal.

Kettocs, J. H. MD., 78.. RE! . Battle Creck, Mich

Kerr, Apram Tucker, Jr., MD., "95... SE ae 61 Waite Ave., Ithaca, N. Y.

Kincspury, Beny. F., A.B., M.S., ’98.. ..125 Dryden Road, Ithaca, N. Y.

Exwreyv, Joe. 3, MK Nis ii las cnccueasuctas 1405 Welton St., Denver, Colo.

Keneparesce, Ts Js W92isn cess cissedissas zor E. High St., Springfield, Ohio

Koromw, Cuartes A., Ph.D., ’99.. ‘Patina’ of California, Berkeley, Cal.

Korz, A. L., M.D., ’or. oe . 32 S. Fourth St. Easton, Pa.

Krarrt, WILLIAM, '9s.. agit Ww. Fifty-ninth St., New York City

Krauss, Wo. C., oad MD, “'90. . . .479 Delaware Ave., Buffalo, N.-Y. _

Kvueune, F. W., ’79.. dees ees veveee 9 Court St, Fort Wayne, Ind. —

Lams, J. Mervin, M.D., ’ot..........-- gto T St., N. W., Washington, D. C. 3

Lanpacre, F. L., B.A., ’03.. . Ohio State University, Columbus, Ohio —

Latuam, Miss V. A., M.D., “DDS. ‘FRMS, "S88, D,

808 Morse mre Rogers Park, Chicago, Ill.

Lawton, Epwarp P., '88.............6- .-3 Linden Ave., Troy, N. ¥.

‘

ZAAAAS:

44K mKExP

Higa

: ;

HITE

4 Hu =I

252.

De ere cere a ene ot

Evan .-18 Locust St, Portland, Me.

Spencer Lens Co. Buffalo, N. Y.

do oberon peas Reve Y.

- Bloomfield Ave., Montclair, N. J.

184 AMERICAN MICROSCOPICAL SOCIETY

Paseacn, Paawn, PRD. 98.2000. c0sceessees 601 Kansas Ave., Topeka, Kan.

Pearse, Artuur S., B.Sc., M.A., 'o2..Harvard University, Cambridge, Mass.

Wasen, Wouw Wi. Bi cvicsciceds cverevccesenwes 1307 Third Ave., Altoona, Pa.

Pamwoce, Ba, 99. ssscnccnscsesvevace 3609 Woodland Ave., Philadelphia, Pa.

Priaum, Manus, Esq, '91..........++----440 Diamond St, Pittsburg, Pa.

Prwonka, Tuos., Esq., '97.. . «+243 Superior St., Cleveland, Ohio

Pounp, Roscor, A.M., PhD, Be cee cceceserecccccce MAO, Mam lm

Powers, Jas. H., rpg as ’o2.. ie --Doane College, Crete, Neb.

Parnce, S. Frep, ’03. . University of Nebraska, Lincoln, Neb.

Pysurn, Georce, MD., '86.. nah -to11 H St., Sacramento, Cal.

Ransom, Brayton H., '99.......-.+-++-1362 B St., S. W., Washington, D.

Reep, Raymonp C., Ph.B., D.V.M., '79....120 W. Hudson St., Elmira, N.

Reysurn, Rozert, M.D., ’90............2129 F St., N. W., Washington, D.

Lister Rajamundry, District Godawari, India i

Scuoney, L., M_D., ’98..... -.-23 W. 135th St., New York City

Seaman, Wa. H., M.D., "86... 41426 Eleventh St, N. W., Wi

Seawet, Benjy. Lez, B.S. (Edin.) ‘or. .308 E. Market St., W:

Suanks, S. G., M.D., '00.........+-+++-++-547 Clinton Ave.,

Suranen, J. Bo, BB. on ccs vccccn cv cccaey tewe OD, GRID eee

Suuttz, Cuas. S., 82...................-Seventh St. Docks, Hoboken,

: i

Smuey, E. R... oscceccccccccvesccsce es 902 Pine St, Philadelphia, Panne

Siemon, Rupees, | ‘gt. . -eeeeeesI21§ Calhoun St., Fort Wayne, Ind. —

Stocum, Cuas. E., PhD, “MD, oe: ..Defiance, Ohio

Smira, J. C., '96.. donee 13 "Carondelet St, New Orleans, La.

Surrm, Tunccces W., Seek sca wans ..171 La Salle St., Chicago, Il

Sraurrer, Rev. T. F., eS RY SPE Eleventh St. Sioux City, lowa —

Sressins, J. H., Jr, Ph.D., me Wie cuesea 351 Fourth Ave., New York City. —

StepMAN, Pror. J. M., ’95.. pares | bare Station, Columbia, Mo.

Stoney, Rosert J., Jr, 106. « . .424 Fifth Ave., Pittsburg, Pa.

Srurpevant, Lazexte B., AB, B BS. 8 . Univ. of sda: Lincoln, Neb.

Summers, Pror. H. E., ’86.. Mee ...Ames, Iowa —

Taytor, Geo. C., LL.D., ’99......437 W. Fourteenth St., Oklahoma City, Oki. —

Tuomas, Artuur H., ’99........Twelfth and Walnut Sts., Philadelphia, Pa.

Tuomas, Pror. Mason B., "90. . . College Campus, Crawfordsville, = Bi

Trains, GEorcE, '96...........0-0000 1410 E. Genesee St., Syracuse, N. Y.

Twininec, Frevericx E., '96.........0s000e- 29 Patterson Block, Fresno, Cal.

Uneicn, Cart J., BS, Of. ...... 000200 Central High School, Duluth, Minn,

Vanvenroet, Frank, M.E., Ph.D., ’87.........- 153 Center St, Orange, N. Je

Vreven, M. A. M.D., '85.............-Broad and Queen Sts. Lyons, N. ¥.

x, W "03... ....+-+--Furman University, Greenville, S. C.

ow. Huwny A. Ph.D., '86......1342 Forsyth Ave, Columbus, Ohio

E J., PhD., oo. .............+++++++-79 Chapel St, Albany, N. Y.

M., MD. PhG., F.R.M.S., 90,

2342 Albion Place, St. Louis, Mo.

ux, G. NOD. oc eccboccccccccceccesce S00 Broadway, New York Cay

mrzy, James D., M.D., F.R.MS., "Bs.....405 S. Main St., Petersburg, Ill.

amp, Martin S., '86..............++.+..21 Walnut St, New Britain, Conn.

OTT, Hewry, A.M., M.D., '98,

University of Nebraska, Lincoln, Neb.

me, FRANK, "Ol...............-228 S, Fifteenth St., Philadelphia, Pa.

SUBSCRIBERS

Frio’ Covumman Muszun. . ceesennanevasseeecese seen ns 2 SCHED m Vs

Corumaia University Lameany.. co cecevees cece cececccs on over inna

Dutau & C0... 0... +e sees eeeeeeeseeeee+e37 Soho Square, London, England

SyRacuse CENTRAL LIBRARY.......ccccccccccccccccccececess S¥ractise, N.Y.

AcapeMy oF NATURAL SCIENCES.............Logan Square, Philadelphia, Pa.

New York ACADEMY OF MEDICINE, a

17 W. Forty-third St, New York City —

Tue Missouri BoranicaL GARDEN.............00+5 Me

Screntiric Liprary.............-.-.-U. S. Patent Office, Washington, D. C a

N. Y. State Verertnary COLLEece.......... Cornell University, Ithaca, N.Y.

U. S. MepicaL Museum Anp Liprary, an

New York State Liprary.................---Serial Section, Albany, N. Y. =

Boston Society or NatuRAL History. ..........-Berkeley St. Boston, Mass.

Liprary oF THE Onto STATE UNIVERSITY............-.+»+--Columbus, Ohio

Lazsoratory oF HISTOLOGY AND Exssevouocy, ps)

ve a of berms: oo Minn, | 4

Lrprary OF THE UNIVERSITY OF NEBRASKA....... Pe: ae ij

S. C. Furrer. . .. Westboro Insane Hosta Westboro,

Liprary OF rue Coonasp Stas NorMAL. . bs Shine ob 0006 wan

Liprary oF THE UNIVERSITY OF MONTANA... 4p sedesee seneewen Missoula,

Pusesc Lammasys vigsdccsses is ov svenccawasan ve oceccececc'ss ln

SAN Framcisco Mscnoscorscat. Sociary. . «eeeeeeeesee5an Francisco, Cal.

Lrprary OF THE Usivensrry or Weacostart.. sosesse yee cooces diana

Bureau oF GovERNMENT LABORATORIES........+.-++++++++++++++Manila, P. 1

Lrprary OF CHICAGO UNIVERSITY... 2... 0000seeeeeeeeeue ee e+ Chicago, mi. i

186

INDEX TO VOLUMES I TO XXV

ithoce Structure of, XXIII: 191.

, Destruction of, by a Fungus, III: 49.

count of a Morbid Growth in a Pig’s Stomach, An—W. H. Birchmore,

Boies Gus the Ill W. H. Walmsley,

C as uminant in Photomicrography—

XVIII: 136.

i, Chromic, Effect of, upon Red Blood Corpuscles, XV: 129; Chromic,

| Rapid Preparation of Tissues, XII: 120; Citric, Production of, by

XV: 90; Picric, for Rapid Preparation of Tissues, XII: 120.

and Visual Focus in Micro-photography with High Powers, The—

D. Cox, VII: 29.

nosp Eichhornii, Development and Reproduction of, X: 107.

te crane St Peaiety pre, Nerve Ca, Sie Paee

: 29.

Deep Sea Life, II: 17; Mounting of, XV: 248

. Agar-agar, XX: 91; Formalin, XV: 192; Formalin—Ad-

: 219; Some Remarks on the Limitation of Tuberculosis, Illus-

: &.

ee ond Berenens aMicsoscepee 1 J. Detmers, X: 149.

American Work on Cestodes in 1893—Henry B. Ward, XV: 183.

Ammoniacal Fermentation of Urine, The—Veranus A. Moore, XII: 97.

_ Amount of Oxygen and Carbonic Acid Dissolved in Natural Waters, On the,

and the Effect of these Cases upon the Occurrence of Microscopic Organ-

_ isms—Geo. C. Whipple and Horatio N. Parker, XXIII: tog.

Amphibia, Lateral Line System of, XVII: 115; Phagocytic Action of Leuk-

- @eytes in, XIX: 93; Peritoneal Epithelium of, XVIII: 76.

_ Amphipleura pellucida, Resolution of, by Central Light, XIT: 170.

; 187

188 . INDEX TO VOLUMES I TO XXV

Amphistomum Fabaceum Diesing, Anatomy of, XI: 85.

Amplifier, Use of, IX: 263.

Amplifying Power of Objectives and Oculars in the Compound Microscope,

On the—Geo. E. Blackham, XI: 22.

Angiosperms, Fecundation of Ovules in, VI: 93.

Anilin Dyes, Reaction of Diabetic Blood to, XXI: 31.

Animal Body, Tube Plan of Structure of, XXV: 63.

Animals, Domestic, Size of Blood Corpuscles of, IX: 216.

Aperture, Angle of, in Air, Water and Balsam, in Relation to Numerical

Angle, VII: 199; as a factor in Microscopic Vision, XVIII: 321; Numerical,

XIV: 44; Numerical, in Relation to Angle of Aperture in Air, Water and

Balsam, VII: 199; Relation of, to Amplification, V: 33.

Apparatus, Discussion of, III: 85; New and Improved, VII: 112.

Apparatus for Holding Cover-glasses, An—Veranus A. Moore, XIII: 51.

Apparatus for Illustrating the Circulation of the Lymph—G. S. Hopkins,

XVII: 336.

Apparatus for the Exhibition of Microscopic Objects—James M. Flint, XIII:

54-

Apparent Structure of the Scales of Siera buskii in Relation to the Scales of

Lepidocyrtus curvicollis, On the—R. L. Maddox, XVIII: 194.

Aqueous Solution of Hematoxylin which does not readily Deteriorate, An—

Simon H. Gage, XIV: 125.

Argulus catostomi, VIII: 144.

Arrangement of the Muscular Layers of the Intestine of the Cat in the Region

of the Juncture of the Large and Small Intestines, The—Robert O. Moody,

XIII: 120,

Arteries, Diseased Cerebral, Trauma in Relation to, XXI: 1.

Arthropods, Cleavage among, XIX: 74.

Aspinwall, John. Methods of Producing Enlargements and Lantern Slides of

Microscopic Objects for Class Demonstrations, XXII: 41.

Astronomical Photography with Photomicrographic Apparatus—A. Clifford

Mercer, XVIII: 132.

Atax (Fabr.) Bruz., North American Species of, XX: 193.

Attacus Cecropia, Structure of, XI: 135.

Atwood, H. F. A New Apparatus for Photo-micrography, VI: 176.

Bacillus, of Cholera, Feeding Insects with, XX: 75; Comma, an Etiological

Factor in Asiatic Cholera, VIII: 84; Comma, Feeding Insects with, XX: 75;

of Diphtheria, XX: 81; of Foot-rot in Sheep, IX: 209; of Leprosy, X: 119.

Bacillus of Foot-rot in Sheep—Mark Francis, IX: 209.

Bacteria, and Disease, VIII: 5; Cultivation of, VII: 142; Dahlia as Stain for, —

XIX: 182; in Ice, XI: 70; in Milk Ducts of Udder, XX: 57; Motile,

Flagella of, XVII: 239; Motile, Standing Flagella on, XIII: 85; on the

Normal Eye, XI: 120; Pathogenic, V: 87; Preparing and Mounting, V: 79;

the Cause of Disease, IX: 193.

Bacteria and Disease: President’s Address—Thomas J. Burrill, VIII: s.

Bacteria in Ice, especially in their Relation to Typhoid Fever—Chevalier Q.

Jackson, XI: 70.

Comparison of the Phagocytic Action of Leukocytes in

Mammalia, (5 Plates), XIX: 93.

| E. The Modern Conception of the Structure and Classification

rr with a Revision of the Tribes and a Rearrangement of the

a _ North American Genera, (1 Plate), XXI: 61; The Modern Conception of

the Structure and Classification of Deemids, with a Revision of the Tribes,

Families and a Rearrangement of the North American Genera, (1 Plate),

XXIV: 27; The Classification of Protophyta, Including a Revision of the

Families, and a Rearrangement of the North American Genera, XXV: 8.

a) 57.

ie Binocular, Wenham, XIV: 57.

__— Biological Reconnoissance of some Elevated Lakes in the Sierras and the

__ Rockies, A—Henry B. Ward, XXV: 127.

_ Birchmore, W. H. An Account of a Morbid Growth in a Pig’s Stomach,

ae ee

Birds, Air-sacs of, XX: 29.

19° INDEX TO VOLUMES I TO XXV

Birge, E. A. President’s Address: The Thermocline and its Biological Sig-

nificance, (2 Plates), XXV: Bs Caterers at eames ere

Sierras and the Rockies, XXV:

Biscoe, Thomas D. The Wenham Binocadar-—Can & be made Adin

a Variable Tube Length? XIV: 57.

Blackham, Geo. E. On the Systematic Examination of Objectives for the

Microscope, with a Convenient Form for Recording Results, I: 62; Should

Homogeneous-immersion Objectives be made Adjustable or Non-adjustable?

III: 62; President’s Address: The Evolution of the Modern Microscope,

IV: 25; The Relation of Aperture to Amplification in the Selection of a

Series of Objectives, V: 33; Memoir of Robert B. Tolles, VI: 41; Memoir

of Thad S. Up de Graff, M.D., F.R.M.S., VII: 216; On the Amplifying

Power of Objectives and Oculars in the Compound Microscope, XI: 22.

Bleile, A. M. Some Notes on the Innervation of the Lungs, (1 Plate), III:

35; Memoir of David Simons Kellicott, B.Sc. B.Ph, Ph.D., XX: 21;

President’s Address: The Detection and Recognition of Blood, XXII: 1.

Bleile, A. M., and Feiel, A. The Effects of Division of the Vagi on the

Heart, IV: 91, 261; The Effects of a Division of the Vagi on the Muscles

of the Heart, V: 47.

Blood, and Blood Stains, XIV: 91; Corpuscular Elements of, XIV: 63; De-

tection and Recognition of, XXII: 1; Diabetic, Reaction of, to Anilin Dyes,

XXI: 31; Drawing for Microscopic Examination, XIX: 186; Effect of

Altitude on, XX: 177; Histology of, XVIII: 49; Methods of Determining

Percentage of Haemoglobin in, XVII: 165; Micro-Organisms in, in Tetanus,

IV: 157; of Frog, Haemosporidia in, XXV: 55; of Necturus and Crypto-

branchus, XV: 39; Preparing in Bulk, XX: 49; Rheumatic, Morphology

of, VI: 194; Study of, III: 30.

Blood and Blood Stains in Medical Jurisprudence—Clark Bell, XIV: 91.

Blood Corpuscles, Comparative Size of in Man and Domestic Animals, IX:

216; of Lamprey, X: 77; of Necturus, VII: 126; Red, Effect of Dilute Solu-

tions of Chromic Acid and Acid Urine upon, XV: 129; Red, Human,

Micrometry of, XX: 41; Red, in Legal Medicine, XVIII: 201; White,

Diapedesis of, XVI: 16s.

Blood of Necturus and Cryptobranchus, The—Edith J. Claypole, XV: 30.

Blood Platelets, XVI: 181.

Blood Stains, Sarcina ventriculi in Medico-legal Investigation of, XV: 136.

Botany, Collodion Method in, XII: 123.

Brain, Comparative Morphology of, XVII: 185; Human, Physiology and

Pathology of, V: 141.

Brain Cavities, Epithelium of, XII: 140.

Brain Sections, Preparation and Mounting, IV: 275.

Branchial Cleft, Growth of the First, I: 57.

Bray, Thomas J. Photomicrography, XVIII: 107.

Brayton, Forest W., M.D., Memoir of, XIII: 171.

Brief Account of the Microscopical Anatomy in a case of Chrome Lead

Poisoning, A—Vida A. Latham, XIII: 110.

Britcher, Horace W. An Occurrence of Albino Eggs of the Spotted Sala-

mander, Amblystoma punctatum L., (1 Plate), XXI: 69.

INDEX TO VOLUMES I TO XXvV 191

ee 0 a 2s.

| a. | T. Brownell Turn-table, VI: 173; Original Method of Staining

. Preparing and Mounting Bacteria, V: 79; The Uredinex of

Disease, VIII: 5; Disease Germs. Another Illustration of the Fact that

Bacteria Cause Disease, IX: 193; The Erysipheae of Illinois, (1 Plate),

; The Ustilagineac, or Smuts; with a List of Illinois Species,

: 45; rage eck gg 533 Report of Working Session, XI: 143;

1+ and

globin in the Blood for Clinical Purposes, XVII: 16s.

Busy Man’s Amateur Microscopic Laboratory, A—Martin S. Wiard, XI: 126.

Butter, Crystallography of, IX: 315; distinguishing of by Means of Micro-

_—s scope, VII: 128; Examination of and Its Adulterations, VIII: 103, 116.

Camera, Handy Photomicrographic, XII, 69; in Detection of Forgery, XII:

86; New Photo-Micro, IX: 263.

Cameras, Photo-micrographic, XVII: 340.

Cancer, Curability of, XXI: 17; Discoveries in relation to, XX: 165.

Carbonic Acid, Dissolved in Natural Waters, Effect of on Microscopic

Organisms, XXIII: 103.

Carcinoma, Cellular Pathology of, XVIII: 248; on Floor of Pelvis, XX: 16s.

Carcinoma on the Floor of the Pelvis. Two Discoveries in Cancerous Dis-

ease—Mary A. Dixon Jones, XX: 16s.

Cardiac Muscle Cells in Man and Certain Other Mammals—B. L. Oviatt,

IX: 283.

Carmine, Picro- and Alum-, as Counter Stains, XX: 337.

Cartilage, Development of, in Embryo of Chick and Man, VII: 76; Sectioning

Fresh, VIII: 142.

Caryophyllales, Histogenesis of XX: 97.

Cataloguing, Labeling and Storing Microscopical Preparations—Simon H.

Gage, V: 169.

192 INDEX TO VOLUMES I TO XXV

Cat, Comparison of Ear with Human, XII: 146; Meibomian Glands in,

143; Muscular Layers of Intestine of, XIII: 120; Soft Palate of, X: 58

Cells, Wax, How to make, VI: 214; Use in Connection with White Zinc

Cement for Fluid Mounts, II: 63.

Centering Block, XVII: 373.

Centimeter Scale A, Comparison with Centimeter Scale Fasoldt II, IX: 299;

Comparison with Standard Centimeter Ruled on Glass, VIII: 83; Further

Study of, VIII: 75; Report on, V: 181; Securing Copies of, XI: 109;

Study of, V: 184; Study of Subdivisions, XI: 64.

Centimeters, Standard, Glass and Speculum Metal, XIII: 71; Manufactured

in Pursuance of the Resolution of A. S. M. adopted in 1889, Description of,

XII: 84; Report on, XIII: 207.

Cephalic Extremity and Movements of the Human Spermatozoon, The—

George E. Fell, V: 121.

Certain Crustacea Parasitic on Fishes from the Great Lakes, On—D, S. Kelli-

cott, I: 53.

Certain Crustaceous Parasites of Fresh-water Fishes, On—D. S. Kellicott,

IV: 73.

Cestode, New Avian, XXI: 213.

Cestodes, American Work on, in 1893, XV: 183.

Chara Coronata, Chlorophyll Bodies of, XVII: 155.

Character of the Flagella, The—Veranus A. Moore, XVI: 217.

Chatauqua Lake, A New species of Copepoda and List of Entomostraca

found at, IX: 246.

Cheap and Efficient Life-box, A—Jas. E. Whitney, VI: 21s.

Cheap Punches for Sheet Wax—Jas. E. Whitney, VI: 21s.

Chester, Albert H. A New Method of Dry Mounting, V: 143.

Chick, Development of Cartilage in Embryo of, VII: 76; Development of

Muscle in Embryo of, VII: 71.

Chick Embryos, for Microscopical Examination, VII: 66; Preparation and

Imbedding, XII: 128.

Chirodota, Spicula of, IV: 139.

Chlamydomonas, XXI: 97; in Connecticut, XXIV: 13.

Chlamydomonas and Its Effect on Water Supplies—Geo. C. Whipple, XXI:

97.

Chlorophyll Bodies of Chara Coronata, The—W. W. Rowlee, XVII: 155.

Cholera, Asiatic, Comma Bacillus an Etiological Factor in, VIII: 84

Cholera Bacillus, VII: 142.

Chrome Lead Poisoning, Microscopical Anatomy in, XIII: r1o.

Cicada septendecim, Ovipositor and Mouth Parts of, XVII: 111.

Circulation, Extra-vascular, VI: 81.

Cittotaenia, XXIII: 173.

Cladocera of Nebraska, The—Chas. Fordyce, XXII: 1109.

Cladocera, of Elevated Lakes in the Sierras and the Rockies, XXV: 149; of

Nebraska, Additional Notes on, XXV: 45.

Classification of Protophyta, The, Including a Revision of the Families, and

a Rearrangement of the North American Genera—Chas. E. Bessey,

XXV: 8o. ;

INDEX TO VOLUMES I TO XXV 193

NiGcs Aeon A New Method for Securing Paraffin Sections to the

___ Slide or Cover-glass, XVI: 65; The Enteron of the Cayuga Lake Lamprey,

_ (io Plates), XVI: 125; Some Points on Cleavage among Arthropods, (1

Plate), XIX: 74.

_ Claypole, Edith J. The Blood of Necturus and Cryptobranchus, (6 Plates),

XV: 39; Notes on Comparative Histology of Blood and Muscle, (5 Plates),

: 49; The Comparative Histology of the Digestive Tract, (1 Plate),

_ Claypole, E. W. On the Value of Cheap Microscopes for Educational Pur-

poses, XIV: 60; Structure of the Bone of Dinichthys, XV: 189; On the

Structure of the Teeth of Devonian Cladodont Sharks, XVI: 191; On the

Teeth of Mazodus, (1 Col. Plate), XVIII: 146; On the Structure of Some

: 269.

ee aad Arranging Diatoms—F. S. Newcomer, VIII: 128.

_ Clearer, for Collodionized Objects, XV: 86.

Cleavage, among Arthropods, XIX: 74.

ees rece ES eee ae aration 430

Tales, (18 Plates), XX:

eS: Clveneer, S. V. Sicceaie ak femsbuar el dae anin Brain, V: 141.

Clinical Advantages of Ozone and its effects on the Micro-Organisms of In-

__ fusions—George E. Fell, V: 60.

Cocaine in the Study of Pond-life—H. N. Conser, XVII: 310.

_ Collodion Method, in Blood Examinations, XIII: 79; in Botany, XII: 123.

Collodion, Oil-sectioning with, XVII: 361.

Collodion Method in Botany—Mason B. Thomas, XII: 123.

Colorado, Entomostraca of, XXIII: 41; Protozoa of, XXIII: 49.

- Combined Focusing and Safety Stage for Use in Micrometry with High

og Powers, A—C. M. Vorce, VII: 115.

_ Comma Bacillus, an Etiological Factor in Asiatic Cholera, VIII: 84.

_ Comma Bacillus of Asiatic Cholera, The. A Reply to Arguments Denying that

it is an Etiological Factor in that Disease—George W. Lewis, VIII: 8%.

Committee of the American Society of Microscopists on Uniformity of Tube-

length, Report of, XII: 250.

Committee on Eye-Pieces, Report of, V: 175.

Committee on Micrometry, Report of, VIII: 197; Report of, X: 163; National,

a History of, V: 17%

Committee on Oculars, Report of, VI: 228.

Committee on the Spencer-Tolles Fund, Report of, XXIII: 26s.

Committee on Standard Micrometer, Report of, VI: 220; Report of, VII:

212.

Committee on Universal Microscope Screw, Report of, VIII: 199.

Comparative Histology of the Digestive Tract, The—Edith J. Claypole,

XIX: 83.

194 INDEX TO VOLUMES I TO XXV

Comparative Morphology of the Brain of the Soft-shelled Turtle (Amyda

mutica) and the English Sparrow (Passer domestica)—Susanna Phelps

Gage, XVII: 18s.

Comparative Size of Blood Corpuscles of Man and Domestic Animals—Freda

Detmers, IX: 216.

Comparative Study in Methods of Plankton Measurement, A—Henry B.

Ward, H. W. Graybill, and others, XXI: 227. +3

Comparative Study of Hair for the Medico-legal Expert, A—Wm. Geo. Rey-

nolds, XIX: 117. .

Comparative Study of the Soft Palate—Wm. Fairfield Mercer, XXI: 41.

Comparison of a Standard Centimeter Ruled on Glass by Chas. Fasoldt, with

Centimeter Scale A—Marshall D. Ewell, VIII: 83.

Comparison of Centimeter Scale, “ Fasoldt II,” with “ Centimeter Scale A.”

—Marshall D. Ewell, IX: 299.

Comparison of the External and Middle Ear of Man and the Cat, A—

Thomas B. Spence, XII: 146.

Comparison of the Fleischl, the Gowers, and the Specific Gravity Methods

of Determining the Percentage of Haemoglobin in the Blood for Clinical

Purposes—F. C. Busch and A. T. Kerr, Jr., XVII: 165.

Comparison of the Phagocytic Action of Leukocytes in Amphibia and Mam-

malia, A—John M. Berry, XIX: 93.

Concave Mirror, The—Marshall D. Ewell, XIV: 43.

Conditions of Success in the Construction and the Comparison of Standards

of Length, On the—William A. Rogers, ITV: 231; V: 240.

Conjugatae, Structure and Classification of, XXIII: 145.

Connecticut, Chlamydomonas in, XXIV: 13.

Connective-tissue corpuscles, of Necturus (Menobranchus), IV: 109.

Conser, H. N. Cocaine in the Study of Pond-life, XVII: 310; Paraffin and

Collodion Embedding, XVII: 312.

Constitution and By-Laws, II: 79; III: 95; VI: 283; VIII: 224; X: 166;

XI: 171; XII: 253; XIV: 39; XVI: 251; XVII: 377; XVIII: 401;

XIX: 190; XX: 355; XXI: 265; XXII: 211; XXIII: 283; XXIV: 181;

XXV: 175.

Consumption, Curability of, XXI: 17.

Contribution to the Life History of the Diatomaceae, A—H. L. Smith, VIII:

30.

Contribution to the Life History of the Diatomaceae—Part II—H. L. Smith,

IX: 126.

Contribution to the Study of Malignant Growths in the Lower Animals, A—

Eva H. Field, XVI: 223.

Contribution to the Study of the Myelin Degeneration of the Pulmonary

Alveolar Epithelium, A—Veranus A. Moore, XV: 77.

Contribution to the Subterranean Fauna of Texas, A—Carl J. Ulrich, XXIII:

83.

Contribution to the Histogenesis of the Caryophyllales—Frederic E.

Clements, XX: 97.

Contributions to the Life-history of Symplocarpus foetidus—W. W. Rowlee

and Mary A. Nichols, XVII: 157.

INDEX TO VOLUMES I TO XXV 195

iit Henry C, Memoir of, XX: 28

apo os sah: ab Mideael Lode ix hs Shacens ant

; 146.

“ ee (Actacodioces Kittoni), VII: 33; Deformed Diatoms, (1 Pilate),

= 178; The Coscinodisceae—Notes on some unreliable Criteria of Genera

____ and Species, (2 Col. Plates), XII: 18; President’s Address: A Plea for

eee ne Sete oe

___~ Plates), XVI: 165; Diphtheria—Its Bacteriology, XVIII: 271.

Seay sontsosts oe ¥ 105; Parasites of, V: 115.

_ Crenothrix manganifera, XXIII: 31.

Critical Study of the Action of a Diamond in Ruling Lines upon Glass, A—

_ (W. A. Rogers, V: 147.

Croup, Vegetable Nature of, IV: rot.

_ Crustacea, Parasitic on Fishes from the Great Lakes, I: 53; Parasitic on

_ Fresh-water Fishes, IV: 7s.

Crustaceous Parasite of the “ Miller's Thumb” (Cottus)—D. S. Kellicott,

i. ae: 76

_ Cryptobranchus, Blood of, XV: 30.

_ Crystallography of Butter and Other Fats, The—Thomas Taylor, (6 Plates),

EX: gts.

ee eee omen

aie ‘Cultural Studies of a Nematode associated with Plant Decay—Haven Met-

_ __eaillf, XXIV: 8.

_ Current Microscopical Notes—J. M. Lamb, XVI: 242.

Curtis, Lester. A Study of Blood, (1 Plate), IIT: 39; Micro-Organisms in

the Blood of a case of Tetanus, [V: 157; The Cultivation of Bacteria, and

the cholera Bacillus, VII: 142.

Curvipes, North American, XXIII: aor.

196 INDEX TO VOLUMES I TO XXV

Custodian, Report of, VI: 282; VII: 213; VIII: 198; IX: 324; XXII: 210;

XXIII: 282; XXIV: 179; XXV: 172.

Cutter, Ephraim. Micrographical Contribution —The Vegetable Nature of

Croup, IV: 101; Morphology of Rheumatic Blood, VI: 194.

Cutting Sections, Hints on, VI: 209.

Cymatogaster, Sex-Cells of, XVII: 172.

Dahlia as a Stain for Bacteria in Sections cut by the Collodion Method—

Raymond C. Reed, XIX: 182.

Daphnella, A New, XII: 172.

Data for the Determination of Human Entozoa—Henry B. Ward, XXIV: 103.

Davies, John Eugene, Memoir of, XXI: 249.

Davis, Ellery W. Memoir of John Eugene Davies, XXI: 249.

Davis, Myron C., Memoir of, IX: 333.

Davis, N. S. Memoir of Hosmer Allen Johnson, M.D., XIII: 172.

Dayton, Robert. Modification of the Wenham half-dise illuminator, with

an improved mounting, IV: 161.

Debt of American Microscopy to Spencer and Tolles, The—Wm. C. Krauss,

XXIII: 19.

Decalcification, Methods of, XIV: 121.

Deck, Lyman. Note on Resolution of Amphipleura pellucida by Central Light,

XII: 170; A New Heliostat, (1 Plate), XIII: 49.

Deecke, Theodore, Preparation and Mounting of Brain Section, IV: 275.

Deep Sea Soundings, II: 17.

Defective Development and Disease, with Special Reference to the Curability

of Consumption and Cancer—M. A. Veeder, XXI: 17.

Defendorf, Allen Ross. Yeasts and their Relation to Malignant Tumors,

XVIII: 119.

Deformed Diatoms—Jacob D. Cox, XII: 178.

Degeneration, Myelin, of the Pulmonary Alveolar Epithelium, XV: 77.

Demodex Folliculorum in Diseased Conditions of the Human Face—George

E. Fell, VIII: 120.

Deposition of Silver on Glass and other Non-metallic Surfaces, The—Frank

L. James, VI: 71.

Deposit-glass, Simple and Efficient, XI: 139.

Description of a New Cave Salamander, Spelerpes stejnegeri, from the Caves

of South\estern Missouri—Carl H. Eigenmann, XXII: 189.

Description of a New Genus of North American Water Mites, with Observa-

tions on the Classification of the Group—Robt. H. Wolcott, XXII: 105.

Description of a New Portable Microscope—E. H. Griffith, II: 66.

Description of Ergasilus Chautauquaensis, A. A New Species of Copepoda,

and a List of Other Entomostraca found at Lake Chautauqua, in August,

1886—Charles S. Fellows, IX: 246.

Description of Rotary Section Cutter—J. J. B. Hatfield, VI: 171.

Description of the Standard Centimeters Manufactured in Pursuance of the

Resolution of A. S. M. adopted in 1889—M. D. Ewell, XII: 84

Descriptions of Certain Worms—T. S. Up de Graff, V: 117.

INDEX TO VOLUMES I TO XXV 197

ton of the Gritth Tam TablerE. H. Grit, VI 165.

on of the United States, V: 137; Structure and Classification of,

_ XXII: 89.

n and Recognition of Blood, The. President's Address—A. M. Bleile,

OXXIE: 1

pa of the Absolute Length of Eight Rowland Gratings at 62°

~ Fahr.—William A. Rogers, VII: 151.

Determination of the Number of Trichine or Other Animal Parasites in a

_ Given Quantity of Meat—Simon H. Gage, IX: 191.

Detmers, Freda. The Comparative Size of Blood Corpuscles of Man and

ee 216; Remarks on Pathogenic Bacteria,

ws &.

ee H. J. Poisonous Dried Beef, (1 Plate), VII: 54; The Numerical

\per of an Objective in Relation to its Angle of Aperture in Air,

‘Water and Balsam, VII: 199; Photographing with High Powers by Lamp-

a: 143; American and European Microscopes, X: 149.

Defective, and Disease, XXI: 17.

Eichhornii, On the—John M. Stedman, X:

ne, Dever of Methods in Microscopical Technique—Henry B. Ward, XIX:

; Devi, for Enabling Two Observer to View Object Simultaneously VI:

Tilia fie Testing Reteactive Index of Iamersion Fleide—Hi, 1. Sait,

- Diabetes, Reaction of blood in, to Anilin Dyes, XXI: 31.

Diag Differential, Use of Stains in, XIII: 94; Microscope in, XI: 67.

_ Diagnosis of Tumors—William C. Krauss, XIV: 71.

__ Diamond, Action of, in Ruling Lines upon Glass, V: 149.

_ Diapedesis, of White Blood Corpuscle, XVI: 16s.

Diatomaceae, Life History of, VIII: 30; Life History of,—Part IL, IX:

- Diatoms, Cleaning and Arranging, VIII: 128; Deformed, XII: 178; Mode

of Growth of Hoops, VI: 33; Sporadic Growth of, and Relation to Im-

. Water, IV: 197; Structure and Classification of, XXI: 61;

ao “sn een eeenes oF Oo Yates, Vi: 105.

ee cart ugha Fi hak Rabie Cina Oe

. Burrill, IX: 193.

198 INDEX TO VOLUMES I TO XXV

Distribution of Growths in Surface Water Supplies, On the, and on —

Method of Collecting Samples for Examination—Fred’k S. Hollis, XXII

49.

Division of Labor among Microscopists—J. M. Mansfield, V: 43.

Dog, Structure of Heart Muscle of, XXV: 35.

Doubleday, Henry H., Memoir of, XXI: 250.

Drescher, W. A. E. A New Form of Microscope, Made by Bausch & Lomb

Optical Co., Rochester, XI: 131; Memoir of Maitland L. Mallory, M.D.

XVI: 248.

Drying Oven, XIV: 152. 4

Duffield, Geo. A Few Hints on Hardening, Imbedding, Cutting, Staining and

Mounting Specimens, VI: 209.

Durkee, R. P. H. The Structure of the Diatom Valve, (3 Col. Plates), VI:

105.

Ear, Human, Parasite of, XXII: 81; of Man and Cat; XII: 146.

Early American Microscope, An—Wm. H. Seaman, XIV: 156. a

Early Morphogenesis and Histogenesis of the Liver in Sus scrofa domesticus,

The, including Notes on the Morphogenesis of the Ventral Pancreas—David _

C. Hilton, XXIV: 55. .:

Eastman, Lewis M. Egg-like Bodies in the Liver of the Rabbit, V: 167; __

Some Remarks on Fat-infiltration of the Liver, (1 Plate), VII: 60.

Eel Question, Solution of, XXIII: 5.

Effect of Curvature of the Cover-glass upon Micrometry, The—M. D. Ewell, —

XII: 79. a

Effect of Dilute Solutions of Chromic Acid and Acid Urine upon the Red

Blood Corpuscles of Man, The—M. L. Holbrook, XV: 129.

Effect of High Altitude on Blood Counts—A. Mansfield Holmes, XX: 177.

Effects of a Division of the Vagi on the Muscles of the Heart, The—A. M.

Bleile and Adolph Feiel, V: 47. ae

Effects of Division of the Vagi on the Heart, The—A. M. Bleile and A. Feiel,

IV: ot, 261. ;

Egg-like Bodies in the Liver of the Rabbit—Lewis M. Eastman, V: 167. ae

Eigenmann, C. H. The History of the Sex-Cells from the Time of Segrega-

tion to Sexual Differentiation in Cymatogaster, XVII: 172; The Eyes of

the Blind Vertebrates of North America, II. The Eyes of Typhlomolge

rathbuni Stejneger, (2 Plates), XXI: 49; Description of a New Cave Sala-

mander, Spelerpes stejnegeri, from the Caves of Southwestern Missouri, — x

(2 Plates), XXII: 189; President’s Address: The Solution of the Eel a

Question, (4 Plates), XXIII: 5.

Electricity, ee of, upon Nerve Cells, XVII: 179; Influence of, on Proto

plasm, XII:

Elephantiasis, XIV: 133.

Ellis, Sylvanus A., Notice of Death, XVIII: 397.

Elrod, Morton J. Limnological Investigations at Flathead Lake, Montana,

and Vicinity, July 1899, (9 Plates), XXII: 63.

Elrod, M. J. and Ricker, Maurice. A New Hydra, XXIII: 257.

Embedding, XVII: 312.

INDEX TO VOLUMES I TO XXV 199

and Imbedding, XII: 128; of Chick and Man, Development of

VII: 76; of Chick and Man, First Development of Muscle in,

» Modideation of Some Stenderd

Ewell, Marshall D. A Further Study of Centimeter Scale “ A,” VIII: 75;

Comparison of a Standard Centimeter Ruled on Glass by Chas. Fasoldt,

j New Forms of Stage Micrometers, XII: 76; The Effect of Curvature of

the Cover-glass upon Micrometry, XII: 79; Description of the Standard

«Centimeters Manufactured in pursuance of the Resolution of A. S. M.

adopted in 1889, XII: &; The Microscope and Camera in the Detection of

_ Forgery—Exemplified by Lantern Slides and Photographs of Signatures in

the Jerome will case, (1 Plate), XII: 86; A New Form of Graphological

Stand, XIII: 699; Standard Glass and Speculum Metal Centimeters, XIII:

_- 91; President's Address: The Relation of the Microscope to the Administra-

tion of Justice, XIV: 1; The Concave Mirror, XIV: 43.

a. "The People vs. Colby—Geo. E.

“ VI: 47.

Examination of Legal Documents with the Microscope—Qualifications of Ex-

_ aminer—Geo, E. Fell, XI: 102.

_ Exhibitions, of Microscopic Objects, XIII: 54; Micrscopical, IX: 311.

200 INDEX TO VOLUMES I TO XXV

Expedient for Use in Difficult Resolution, An—R. H. Ward, XXI: 111.

Experimental Study of Aperture as a Factor in Microscopic Vision, An.

President’s Address—A. Clifford Mercer, XVIII: 321.

Experiments in Feeding some Insects with Cultures of Comma or Cholera

Bacilli—R. L. Maddox, XX: 75.

Expert Testimony, Hints on, XIII: 64.

Extra-vascular Circulation, The—J. Redding, VI: 8r.

Eye, An Imperfection of, VII: 91; Bacteria on, XI: 120.

- Eye-piece, Use of, in Photo-micrography, XII: 50.

Eye-Pieces, Report of Committee on, V: 175.

Eyes of the Blind Vertebrates of North America, The, Il. The Eyes of

Typhlomolge rathbuni Stejneger—Carl H. Eigenmann, XXI: 49.

Face, Human, Demodex Folliculorum in Diseased Conditions of, VIII: 120.

Fallacies of Popular Bacterial Research, The—George W. Lewis, IX: 254.

Fasoldt Stage Micrometer, On the—T. C. Mendenhall, IV: 2o1.

Fasoldt Test-plate, IX: 318.

Fat Cells, of Necturus (Menobranchus), IV: 109. a

Fats, Crystallography of, IX: 315; distinguishing of by Means of Microscope,

VII: 128. F

On the Fecundation of Ovules in Angiosperms—John Kruttschnitt, VI: 93. Pe

Feiel, A., and Bleile, A. M. The Effects of Division of the Vagi on the

Heart, IV: 91, 261; The Effects of a Division of the Vagi on the Muscles

of the Heart, V: 47. a

Fell, Geo. E. Treasurer's Report, Il: 80; The Binocular Microscope and

Stereoscopic Vision, III: 69; Treasurer’s Report, III: 97; Treasurer’s Re-

port, IV: 286; Clinical Advantages of Ozone and its Effects on the Micro- — om

Organisms of Infusions, V: 69; The Cephalic Extremity and Movements

of the Human Spermatozoon, V: 121; Report of Treasurer, V: 219; Ex- __

amination of Agreement, Exhibit “B”—The People vs. Colby, VI: 47;

Report of Treasurer and Custodian, VI: 282; Memoir of Jas. N. Scatcherd, —

VII: 222; Demodex Folliculorum in Diseased Conditions of the Human

Face, VIII: 120; Report of Committee on Micrometry, X: 163; The Micro-

scope in Diagnosis, XI: 67; Examination of Legal Documents with the

Microscope—Qualifications of Examiner, XI: 102; Microscopical Examina- _

tion of and Experiments with Glandular Secretions according to Method of

Dr. Brown Sequard, XI: 115; A Simple and Efficient Deposit-glass, XI: :

139; President’s Address: The Influence of Electricity on Protoplasm, (2—

Col. Plates), XII: 1.

Fellows, Charles S. A Description of Ergasilus Chautauquaensis. A New

Species of Copepoda, and a List of Other Entomostraca found at Lake —

Chautauqua in August, 1886, IX: 246.

Fermentation, Ammoniacal, of Urine, XII: 97; Production of Citric Acid by,

XV: 90.

Ferns and their Development—John Kruttschnitt, V: 135.

Ferris, Charles R. Notice of death, V: 245.

Ferris, H. B. Memoir of Albert E. Loveland, M.A., M.D., XXI: 251.

Field, Eva H. A Contribution to the Study of Malignant Growths

Milcan necxs ig

Fish, Pierre A. The Epithelium of the Brain Cavities, (1 Plate), XII: 140;

A New Clearer for Collodionized Objects, XV: 86; The Action of Strong

Carrents of Electricity upon Nerve Cells, (1 Plate), XVII: 179; The Use

eee elionperg 98; Parasites of, XV: 173.

coheed EE 217; of Motile Bacteria, XVII: 239; on Motile

SUC cs, Pragunites eal’ baoetinn of, V: 6s.

Forceps, Cover-slip, XVI: 123.

: y Pendyce, Chas. The Cladocera of Nebraska, (4 Plates), XXII: 119; Addi-

tional Notes on the Cladocera of Nebraska, (1 Plate), XXV: 45.

| “Forensic Microscopy or, the Microscope in its Legal Relations. President's

___ Address—William J. Lewis, XI: 5.

Forgery, Microscope and Carers in Detection of, XII: #6

Form and Size of the Red Blood Corpuscles of the Adult and Larval Lamprey

Eels of Coons Tatas tiled Mate taney a)

_ Formalin, Notes on, XVI: sats ies 0h, ta dens XVII: sro.

Formalin—W. W. Alleger, XV: 192.

202 INDEX TO VOLUMES I TO XXV

Formalin—Addenda—W. W. Alleger, XV: 219.

Formalin as a Hardening Agent for Nerve Tissues—William C. Krauss

XVII: 315.

Formalin in the Zoological and Histological Laboratory—D. S. Kellicot,

XVII: 331.

Forms observed in Water of Lake Erie—C. M. Vorce, III: 51.

Forms of Bacteria on the Normal Eye—Lucien Howe, XI: 120.

Forty Years’ Acquaintance with the Microscope and Microscopsts—Chares Fl

E. West, VIII: 161. ;

Fowl, Internal Parasites of, V: 131. ;

Fox, Oscar C., Memoir of, XXV: 163.

Francis, Mark. The Bacillus of Foot-rot in Sheep, IX:

Freshwater Investigations during the last Five Al a B. Ward, XX:

261.

Fresh-Water Sponge—Henry Mills, IV: 209, 253.

Frog, Haemosporidia in blood of, XXV: 55.

Fruit, Structure of, in Ranunculaceae, XVI: 60.

Full Utilization of the Capacity of the Microscope and Means for Obtaining

the Same, The—Edward Bausch, XII: 43.

Fuller, Henry Weld, Memoir of, XIV: 160.

Fungi found in Sewage-effluents—A. W. Bennett, VI: bi

Further Study of Centimeter Scale “ A,” A_Marshail D. Ewell, VIII: 75.

Further Study of the Subdivisions of the First Millimeter of Centimeter

“ A,” A—Marshall D. Ewell, XI: 64.

Gage, Simon H. Observations on the fat cells and connective-tissue cor-

puscles of Necturus (Menobranchus), (1 Plate), IV: 109; Cataloguing,

Labeling and Storing of Microscopical Preparations, V: 169; Serial Sec-

tions, VI: 202; Notes on the Epithelium Lining the Mouth of Necturus

and Menopoma, and Notes on the Blood-corpuscles of Necturus, VII: 126;

Microscopical Tube-length, and the Parts Included in it by the Various

Opticians of the World. The Thickness of Cover-glass for which Unad-

justable Objectives are Corrected, IX: 168; Determination of the Number

of Trichinae or Other Animal Parasites in a Given Quantity of Meat, D

191; Form and Size of the Red Blood Corpuscles of the Adult and Larval

Lamprey Eels of Cayuga Lake, X: 77; Picric and Chromic Acid for the

Rapid Preparation of Tissues for Classes in Histology, XII: 120; Notes

on Fibrin, Oxyhaemoglobin Crystals, and the Collodion Method, XIII: 795

Methods of Decalcification in which the Structural Elements are Preserved,

XIV: 121; An Aqueous Solution of Hematoxylin which does not readily

deteriorate, XIV: 125; A Marker for Indicating the Position of Objects or

Parts of Objects in Microscopical Preparations, XVI: 112; President's

Address: The Processes of Life Revealed by the Microscope; a Plea f

Physiological Histology, XVII: 3; Improvements in Oil-sectioning \,

Collodion, XVII: 361; Histology and Methods of Instruction, XVIII: 299; _

Notes on the Isolation of the Tissue Elements, XIX: 179; Memoir of Wr

A. Rogers, A.M., Ph.D., LL.D., XX: 25; Memolr of Heery CC

SNOEX TO VOLUMES 3 TO XXV 203

SEES PRD., KX: a8; Some Laboratory Apparates, XXI: 107; Modiéce-

Sens Sosnrat Rburienw Postiaate Gas Weil od Gee Whtctogie

, Simon Henry and Gage, Susanna Phelps. Staining and Permanent

Preservation of Histological Elements Isolated by Means of Caustic Potash

(KOH) or Nitric Acid (HNO,), XI: 34

ge, Simon H. and Hopkins, Grant S. Preparation and Imbedding the

Embryo Chick, XII: 128

¢, Susanna Phelps. Ending and Relation of the Muscular Fibres in the

of Minute Animals. (Mouse, Mole, Bat and English Sparrow.)

Abstract, IX: 207; The Intramuscular Endings of Fibers in the Skeletal

‘Muscles of the Domestic and Laboratory Animals, (1 Plate), XII: 132;

_A Reference Model, XIV: 154; Comparative Morphology of the Brain of the

et Tete (Amyda seen ae Ge Feaeeh Merrow, Coe

Gomphogaster Areolatus, IX: 250; Notes on, XII: 174.

_ Graphological Stand, A New, XIII: 69.

Gratings, Rowland, Absolute Length of, VII: 151.

_ Graybill, H. W. Some Points in the Structure of the Acanthocephala, (1

Plate), XXIII: 191.

Graybill, H. W., Ward, Henry B., and others. A Comparative Study in

_ Methods of Plankton Measurement, (3 Plates), XXI: 227.

Green, —. The Peritoneal Epithelium of Some Ithaca Amphibia,

_ Gregarina, in the American Lobster, III: 47

a 5. H Scotties ofc tio Worutia Meimceanse, Yes 6; The Im-

proved Griffith Club Microscope, IV: 149; Descriptions of the Griffith

___-—s«- Turntables, VI: 165; Griffith Microscopist’s Working Cabinet, VI: 168;

Some New and Improved Apparatus, VII: 112; On Several New Micro-

_-—s gwcopical Accessories, VIII: 130; A New Fine Adjustment, X: 161; Three

New Accessories for the Microscope, XIII: 47; Memoir of, XV: 247.

Growth of the First Branchial Cleft, On the—Lucien Howe, I: 57.

Growths, Malignant, in Lower Animals, XVI: 223.

204 INDEX TO VOLUMES I TO XXV

Gundlach, Ernst. On Light and Illumination, IV: 79, 255; An Improve-

ment in Objectives, VI: 148; On Immersion Objectives, VII: 51; Optical —

Errors and Human Mistakes, VIII: 157. Bers, ts

Guttenberg, Gustave, Memoir of, (Portrait p. 399), XVIII: 399.

Haematoblasts and Blood Platelets—M. L. Holbrook, XVI: 181.

Haemoglobin, Methods of Determining, XVII: 165. a ;

Haemosporidia, in Blood of Frog, XXV: 55. ay |

Hair, Comparative Study of, XIX: 117. ef g

ani Microscopically Examined and Medico-legally Considered—William =

J. Lewis, VI: 50. ae

Hamlin, F. M. The Wheel-like and other Spicula of the Chirodofa of Ber- i

muda, (1 Plate), IV: 139; The Microscopical Examination of Seminal uk

Stains on Cloth, V: 21; The Preparation and Mounting of Foon

with Description of a New Slide for Opaque Objects, V: 65; The Ideal

Slide, VI: 179. a

Handy Photomicrographic Camera, A—W. H. Walmsley, XII: 69.

Hardening, Hints on, VI: 2009.

Hatfield, J. J. B. Description of Rotary Section Cutter, VI: 171. =

Hawkshurst, D. C., Obituary Notice of, IV: 23. a

Health, Nerve Elements in, and in Disease, XVI: 234. is

Heart, Effects of Division of Vagi on, IV: 91; Effects of Division of Vagi ou) ia

the Muscles of, V: 47; Muscle Cells of, IX: 283; Structure of Muscles ba a

of Dog, XXV: 35. a

Heliostat, A New, XIII: 49.

Heliostat for Phcho-aalcrngragty, A—S. W. Stratton and T. J. Burrill, vit i

103.

Hematoxylin, An Aqueous Solution of, XIV: 125. oi

Hemospast. A New and Convenient Instrument for Drawing Blood for ¥

Microscopic Examination—Veranus A. Moore, XIX: 187. ems

Henrici, Jacob F. Note on a Microscope Presented by Linneus to Berard |

Jussieu in 1738, IX: 214. ae |

Henrici, J. F. and Mellor, C. C. An Old Microscope of the Cape Tr ec

X: 140.

ring in Peritoneal and Vascular Endothelium, (2 Plates), XXIII: oa

Hilgard, J. E. Report on Centimeter Scale, A, 1882, V: 181. mes ps

Hilton, David C. The Early Morphogenesis and Histogenesis of the

in Sus scrofa domesticus, including Notes on the Morphogenesis of

Ventral Pancreas, (4 Plates), XXIV: 55.

Hints on Expert Testimony—Henry L. Tolman, XIII: 64.

Histogenesis, of Caryophyllales, : 97. Lan

Histogenesis and Morphogenesis, Early, of the Liver in Sus scrofa domesticus, .

including Notes on the Morphogenesis of the Ventral Pancreas—David hal ae.

Hilton, XXIV: 55. A i

Histological Conformation of the Medulla, The—William C. Krauss, XV: as

167.

INDEX TO VOLUMES I TO XXv 205

Materials for, II: 60.

XVII: 3; of Animal Body, Tube Plan of, XXV: 63

pe searedeaetanpeateseesaltc g ey sae

= Si caval teste of tor Latins TV, 131; The Termination of the

Ser ee a ve Peveicomant of Manda in the Eaters

Of the Chick and Man, VII: 71; Studies of the Development of Cartilage

the Embryo of the Chick and Man, VII: 76; Microscopical Researches on

Corpuscular Elements of Blood, XIV: 63; The Effect of Dilute Solu-

of Chromic Acid and Acid Urine upon the Red Blood Corpuscles of

EPRE EE?

iiiaias, Grant $. Structure of the Stomach of Amis calve, (1 Plate), XII

165; Apparatus for Illustrating the Circulation of the Lymph, XVII: fara

and Gage, Simon H. Preparation and Imbedding the

: 128

permanent and free from “ Sweating "—J. T.

f neat,

=) Howe, Lucien, On the Growth of the First Branchial Cleft, I: sy; An Im-

perfection of the Eye, and Test Objects for the Microscope, .VII: 91;

N °

Face, Demodex Folliculorum in Diseased Conditions of, VIII: 120.

Red Blood Corpuscle, Micrometry of, XX: 41.

Eatvematy snd Movements of, V: tat.

177; New Genus of, XXII: tos.

206 INDEX TO VOLUMES I TO XXV

Hymenolepis carioca (Magalhaes) and Hymenolepis megalops (Nitzsch), |

On, with Remarks on the Classification of the Group—B. H. Ransom,

XXIII: 151.

Ideal Slide, The—F. M. Hamlin, VI: 179.

Illinois, Erysipheae of, IX: 301; Smuts of, X: 45; Uredineae of, VII: 93.

Illumination, IV: 79, 255.

Illuminator, Iris, VI: 160; Wenham half-disc, IV: 161.

Imbedding, Sections, Hints on, VI: 209.

Imbedding and Sectioning Mature Seeds—Willard W. Rowlee, XII: 113.

Immersion Fluids, Testing Refractive Index of, VII: 83.

Immersion Objectives, On—Ernst Gundlach, VII: 51.

Imperfection of the Eye, and Test Objects for the Microscope, An—Lucien

Howe, VII: 91.

Improved Griffith Club Microscope, The—E. H. Griffith, IV: 149.

Improved Method of Constructing Slide Cabinets, An—Henry E. Summers,

VII: 108.

Improved Slide for the Examination of Caseous Matter, An—E. L. Shurley, |

III: 6s.

Improved Syracuse Solid Watch Glass, The—A. Clifford Mercer, XVII: 371.

Improvement in Objectives, An—Ernest Gundlach, VI: 148.

Improvements in Oil-sectioning with Collodion—Simon H. Gage, XVII: 361.

Increasing Pollution of our Municipal Water-supplies, The—Frank J. Thorn-

bury, XVIII: 1&2.

Incubator for Student Use, An—Veranus A. Moore, XXI: 103.

Index to Current Literature of Microscopy, XV: 259; XVI: 26s.

Indiana, Plankton of Lake Maxinkuckee, XXIII: 61.

Indices, IV: 293; VI: 204; VIII: 237; X: 166; XII: 265; XIV: 179; XVI:

261; XVIII: 417; XX: 365; XXII: 223; XXIV: 193; General Index to

vols. I-XXV, XXV: 187.

Inflammation, Microscopic Phenomena of, XVI: 16s.

Influence of Electricity on Protoplasm, The. President’s Address—George

E. Fell, XII: 1.

Infusoria, Fresh-water, X: 97; Fresh-water, Observations and Descriptions

of New Species, VII: 38; from Louisiana, XIX: 55; from Louisiana, — “i

XX: 51; from Louisiana, XXI: 87; New and Rare, IX: 187; Notes on,

VI: 126; Observations on, with Descriptions of New Species, VI: 110; on

the Cray-Fish, V: 105.

Injections, Fine, Nitrite of Amy] for, VIII: 140.

Insects, the Destructive Powers of, I: 68; Feeding, with Cultures of Bacilli,

XX: 75; Luminous Organs of, XIII: 133.

Intestines, Muscular Tunic of, XVI: 197; of Cat, Muscular Layers of, XIII:

120.

cernua—Karl M. Wiegand, XVII: 174.

Internal Parasites in the Common Fowl—Thomas Taylor, V: 131. Pe

Intramuscular Endings of Fibers in the Skeletal Muscles of the Domestic nak

and Laboratory Animals, The—Susanna Phelps Gage, XII: 132. ee

Intercellular Spaces in the Embryos of Erechthites hieracifolia and Bidens =

INDEX TO VOLUMES I TO XXV 207

Inco. iE Wier ieades of Comic: (C. seaman), (x Pld,

James, Bushrod Wj Memoir of, XXV: 160.

James, Frank L. The Deposition of Silver on Glass and other Non-metallic

_ Surfaces, VI: 71; Cover-glass Cleaner, VI: 181; Mounting, Finishing and

_ Preserving Slides, VIII: 148; Shrinkage of Cement-cells the cause of

and Creeping in Glycerin Mounts, IX: 173; President’s Address,

in the Investigation of Burns and Scorches on Textile

= 7 a

Allen, Memoir of, XIII: 172.

Dixon. Carcinoma on the Floor of the Pelvis. Two Dis-

in Cancerous Disease, (1 Plate), XX: 16s.

The Plankton of Lake Maxinkuckee, Indiana, XXIII: 61.

. S. On Certain Crustacea Parasitic on Fishes from the Great

Se Plates), I: 53; Observations on Lerneocera cruciata, I: 64; Ler-

e% tortua, n. s. (1 Plate), Il: 41; On Certain Crustaceous Parasites

_ Of Fresh-water Fishes, IV: 75; Polyzoa—Observations on Species detected

near Buffalo, N. Y., (1 Plate), IV: 217; On Some infusoria Found on the

_ Cray-Fish, V: 105; Cothurnia lata, N. S., V: 113; Notes on Two Parasites

of the Cray-Fish, V: 115; Observations on Infusoria, with Descriptions of

_ New Species, (1 Plate), VI: 110; Notes: Infusoria, Rotatoria, ete, VI:

126; Observations on Some Fresh-water Infusoria. With descriptions of

a Species Regarded as New, (1 Plate), VII: 38; A New Floscule,

(1 Plate), VII: 48; A Note on Argulus catostomi, VIII: 144; Additional

Notes on Certain Species of Rotifera, IX: 181; Some New and Rare In-

: 187; Report ’

Michigan, X: 84; Observations on Fresh-water Infusoria, X: o7; A New

Rotiferon, XI: 32; Crustaceous Parasite of the “ Miller's Thumb”

(Cottus), XIV: 76; Formalin in the Zoological and Histological Labora-

tory, XVII: 331; The Rotifera of Sandusky Bay, XVIII: 155; The Rotifera

of Sandusky Bay, (Second paper), XIX: 43; Memoir of, XX: a1.

Kellogg, Clifford Walcott. A Study of the Cellular Pathology of Carcinoma,

(3 Col. Plates), XVIII: 248.

Kenyon, Lorenzo M. Memoir of, X: 16s.

208 INDEX TO VOLUMES I TO XXV

Kerr, Jr., A. T. and Busch, F. C. Comparison of the Fleischi, the Gowers,

and the Specific Gravity Methods of Determining the Percentage of Haemo- __ ne ;

globin in the Blood for Clinical Purposes, XVII: 165.

Kidney, Termination of Nerves in, V: 51. ;

Killing of Invertebrata in an Expanded and Natural Condition—J, M. Sted-

man, XIII: 73.

Kingsbury, Benjamin F. The Histological Structure of the Enteron of Nec-

turus maculatus, (8 Plates), XVI: 19; The Lateral Line System of Sense

Organs in Some American Amphibia, and Comparison with the Dipnoans,

(5 Plates), XVII: 115; Spermatheca and Methods of Fertilization in Some

American Newts and Salamanders, (4 Plates), XVII: 261; The Regenera-

tion of the Intestinal Epithelium in The Toad (Bufo lentiginosus ameri-

canus), during Transformation, XX: 45.

Kinsman, D. N. Tumor of the Left Auricle, (3 Plates), III: 29.

Kofoid, Chas. A. The Plankton of Echo River, Mammoth Cave, XXI: 113.

Krauss, William C. Some Methods of Treating Nerve Tissues, XII: 116;

The Microscope as a Factor in the Diagnosis, Prognosis, and Treatment

of Morbid New Growths, XIII: 61; The Diagnosis of Tumors, XIV: 71;

The Histological Conformation of the Medulla, (1 Plate), XV: 167; Sim-

plification of Laboratory Methods, XVI: 119; The Nerve Elements in

Health and Disease, (1 Plate), XVI: 234; Formalin as a Hardening Agent

for Nerve Tissues, XVII: 315; A New Way of Marking Objectives, XVII:

359; The Requisites of a Pure Water Supply, XVIII: 165; President's

Address: Some Medico-legal Aspects of Trauma in Relation to Diseased

Cerebral Arteries, XXI: 1; The Debt of American Microscopy to Spencer

and Tolles, (5 Plates), XXIII: 19.

Kruttschnitt, John. Ferns and their Development, V: 135; On the Fecunda-

tion of Ovules in Angiosperms, VI: 93; Pollen-tubes Again, (1 Plate),

VII: 62.

Laboratory, Apparatus, XXI: 107; Embryologic, Apparatus of, XXIII: 259;

Formalin in, XVII: 331; Histologic, Apparatus of, XXIII: 259; Mt. Pros-

pect, XXII: 25; Laboratory, Microscopic, A Busy Man’s Amateur, XI:

126; Simplification of Methods, XVI: 119.

Laboratory Photographic Apparatus—Simon Henry Gage, XXIII: 263.

Lake Erie, Forms observed in, III: 51; Microscopic Forms from, IV: 187.

Lake Maxinkuckee, Indiana, Plankton of, XXIII: 61.

Lakes, Elevated, Biological Reconnoissance in some, XXV: 127.

Lamb, J. Melvin, The Microscope in the Government Work in Washington,

(3 Plates), XIII: 13; Current Microscopical Notes, XVI: 242; Some —

Methods of Histologic Technique, XVIII: 291.

Lamprey, Enteron of, XVI: 125. zl

Lantern Slides, Enlarging, XXII: 41; of Photomicrographs and Photomicro- ae

graphic Apparatus, XIV: 141.

Lard Adulterations, Microscope in the Detection of, V: 97.

Last, Louis, Notice of Death of, XVIII: 397.

Lateral Line System of Sense Organs in Some American Amphibia, The, and

Comparison with the Dipnoans—B. F. Kingsbury, XVII: 115.

INDEX TO VOLUMES I TO XXV 209

» Vide A. The Use of Stains, especially with Reference to Their

iV for Differential Diagnosis, XIII: 94; A Brief Account of the Micro-

~ scopical Anatomy in a Case of Chrome Lead Poisoning, XIII: 110; A Brief

Study of a Case of Elephantiasis and Its Histology, XIV: 133; A Plea

_ for the Study of Re-agents in Micro Work, XV: 209; The Question of Cor-

_ fect Naming and Use of Micro-Reagents, XVII: 350; What is the Best

_ Method of Teaching Microscopical Science in Medical Schools, XVIII:

aaa bead nga ones co may 31.

of, XXIV: ss; of Rabbit, Egg-like Bodies in, V: 167; Termination of the

2 Nerves in, IV: 95, 264

Lobster, Structure of Muscles, TV: 131.

Logan, James H. A New Form of Life-slide, VII: 110; Remarks on a

Device for Enabling Two Observers to View Objects Simultaneously,

VII: 120.

210 INDEX TO VOLUMES I TO XXV

Louisiana, Infusoria from, XIX: 55; XX: 51; XXI: 87; New Species of

Rotifer from, XXV: 121.

Loveland, A. E. A Study of the Organs of Taste, (3 Plates), XIX: 129;

Memoir of, se ac On the Luminous Organs of Insects—William H.

Seaman, XIII:

Lungs, eek 71 III: 35.

Lyman, Rufus Ashley. Studies on the Genus Cittotaenia, (2 Plates), XXIII

173.

Lymph, Illustrating Circulation of, XVII: 336.

Lyon, H. N. Notes on the Structure of the Moth Attacus Cecropia, XI: 135;

A Cover-glass Support for Solid Mounts, XII: 75.

Maddox, R. L. On the Apparent Structure of the Scales of Seira buskii in

Relation to the Scales of Lepidocyrtus curvicollis, (1 Plate), XVIII: 194;

Experiments in Feeding some Insects with Cultures of Comma or Cholera

Bacilli, (1 Plate), XX: 75; Memoir of, XXV: 155.

Magnifying Power of Microscope Objectives and Lenses, The—Walter H.

Bulloch, VI: 183.

Mallory, Maitland L. Memoir of, XVI: 248.

Mammalia, Phagocytic Action of Leukocytes in, XIX: 93; Cardiac Muscle

Cells in, IX: 283.

Mammoth Cave, Plankton of Echo River, XXI: 113.

Man, Cardiac Muscle Cells in, IX: 283; Comparison of Ear with Cat’s, XII:

146; Development of Cartilage in Embryo of, VII: 76; Effect of Dilute

Solutions of Chromic Acid and Acid Urine upon Red Blood Corpuscles,

XV: 129; First Development of Muscle in Embryo of, VII: 71; Muscular

Tunic of Intestines of, XVI: 197; Size of Blood Corpuscles of, IX: 216.

Mansfield, J. M. Division of Labor Among Microscopists, V: 43.

Manton, W. P. On the Preparation of Chick Embryos for Microscopical

Examination, VII: 66.

Marker for Indicating the Position of Objects or Parts of Objects in Micro-

scopical Preparations, A—Simon H. Gage, XVI: 112.

Marsh, E. Dwight. Copepoda of some Elevated Lakes in the Sierras and the

Rockies, (2 Plates), XXV: 146.

Mazodus, Teeth of, XVIII: 146.

McCalla, Albert. President’s Address: The Verification of Microscopic Ob-

servation, V: 1.

McIntosh, L. D. A Microscope Attachment, for Use with Solar or Artificial

Light for Projecting, or Photographing, Microscopic Objects with Oblique

Illumination, or Projecting Opaque Objects, X: 155; The Portable Lime

Light, XIII: 41.

Medical Jurisprudence, Blood and Blood Stains in, XIV: 91.

Medical Microscopy—A. A. Young, XX: 87.

Medico-legal, Study of Hair, XIX: 117.

Medulla, Histological Conformation of, XV: 167.

Meibomian Glands in the Cat, The. Note—E. H. Sargent, VIII: 143.

INDEX TO VOLUMES I TO XXV aur

lar Arrangement of Powell & Lealand, IV: 127; Syracuse Solid Watch-

glass, VI: 178; Photomicrograph versus Microphotograph, VIII: 131; On

3 i $0; A Series of Lantern Slides of Photomicrographs and

Phstenianenlias

qmeperetes, XIV: 141; The Improved Syracuse Solid Watch Glass, XVII:

371; Photomicrograph versus Microphotograph, XVIII: 131; Astronomical

Ct Cat isteshieateahtc Aggention (1 Plate), XVIII: 132;

_ President's Address: An Experimental Study of Aperture as a Factor in

@ ; _ Microscopic Vision, (4 Plates), XVIII: 321.

Mercer, Wm. Fairfield. Comparative Study of the Soft Palate, (2 Plates),

XXI: 41.

w | Merriman, C. C The Preparation and Mounting of Double Stainings, I: 71.

Metal Centering Block for Mounting, A—M. Pflaum, XVII: 373.

Metals, Radiation of Heat between, X: 33; The Microscope in the Study of

DP Skitenit Haven: Cultural Studies of a Nematode ssecciated with Plant

Decay,

, (t Plate), XXIV: 89.

— Meteoric Dust, Notes on Alleged, XVII: 95.

_-——s« Method of Preparing Nucleated Blood in Bulk for Class Demonstration—T.

E. Ocrtel, XX: 49.

aa. ee

142.

se 3 Methods, Discussion of, III: 85; Improved, VII: 124.

Michigan, Rotifera of Shiawassee River, X: 8%.

Micrographical Contribution —The Vegetable Nature of Group—Ephraim

Cutter, IV: tor.

212 INDEX TO VOLUMES I TO XXV

Micrometer, Fasoldt Stage, IV: 201; Standard, Report of Committee on, VI:

220; Standard, Report of Committee on, VII: 212; Standard, Rules for the

Control of, V: 200.

Micrometers, Filar, XIV: 132; Stage, New Forms of, XII: 76.

Micrometer Wires—R. H. Ward, VIII: 89.

Micrometry, Combined Focussing and Safety Stage for Use in, with High

Powers, VII: 115; Effect of Curvature of the Cover-glass upon, XII: 79; —

of Human Red Blood Corpuscle, XX: 41; Report of Committee on, VIII:

197; Report of eon fone X: 163; Report of National Committee on,

V: 181; Report on, XI:

Micrometry of Human Red Blood Corpuscle—Frank Judson Parker, XX: 41.

Micro-Organisms in the Blood of a case of Tetanus—Lester Curtis, IV: 157.

Microphotograph, versus Photomicrograph, VIII: 131; XVIII: 131.

Micro-photography, Actinic and Visual Focus in, VII: 29. (See Photo-

micrography. )

Micro-photography with Dry-plates and Lamplight, and its application to

making lantern positives—W. H. Walmsley, IV: 179, 273.

Microscope, Accessories for, XIII: 47; An Early American, XIV: 156; An

Old, X: 140; Binocular and Stereoscopic Vision, III: 69; Binocular, of

the Seventeenth Century, XII: 57; Microscope, College, XII: 67; Evo-

lution of, IV: 25; Microscope, Forty Years’ Acquaintance with, VIII:

161; Full Utilization of Capacity of, XII: 43; Griffith, XIV: 53; Im-

proved Griffith Club, IV: 149; in Detection of Forgery, XII: 86; in

Diagnosis, Prognosis, and Treatment of Morbid New Growths, XIII:

61; in Examination of Legal Documents, XI: 102; in Government Work

in Washington, XIII: 13; in the Workshop, XIV: 128; New Accessories,

VIII: 150; New Form of, XI: 131; New Portable, Il: 66; One Presented

by Linnzus to Bernard Jussieu in 1738, IX: 214; Physician and, XVIII:

71; Plea for Instruction in Technique, XV: 1; Processes of Life Revealed

by, XVII: 3; Relation of, to Administration of Justice, XIV: 1; Test Ob-

jects for, VII; 91; Tube-length, IX: 168; Value of, in Preventive Medicine,

XVI: 101; Zentmayer’s Dissecting, XIV: 51.

Microscopes, American and European, X: 149; Cheap, XIV: 60; Combined

Inverted and Vertical, VIII: 148; New American, XIII: 116.

Microscope and Camera in the Detection of Forgery, The—exemplified by

Lantern Slides and Photographs of Signatures in the Jerome will case—

M. D. Ewell, XII: 86.

Microscope as a Factor in a Study of the Behavior of Metals under Varia-

tions of Temperature, The. President’s Address—William A. Rogers,

Tx: g.

Microscope as a Factor in the Diagnosis, Prognosis, and Treatment of Morbid

New Growths, The—William C. Krauss, XIII: 61.

Microscope Attachment, for Use with Solar or Artificial Light for Projecting,

or Photographing, Microscopic Objects with Oblique Illumination, or Pro-

jecting Opaque Objects, A—L. D. McIntosh, X: 155.

Microscope in Diagnosis, The—George E. Fell, XI: 67.

eT a er

a ee

| INDEX TO VOLUMES I TO XXv 213

ope in the Detection of Lard Adulterations, The—William T. Belfield,

in the Government Work in Washington, The—J. Melvin Lamb,

scope in the Investigation of Burns and Scorches on Textile Fabrics,

The. _President’s Address—Frank L. James, XIII: 1.

sope in the Workshop, The—Wm. A. Rogers, XIV: 128.

ieroscope Stand, A—T. J. Burrill, XT: 53.

Stand, with Concentric Movements, V: 147.

Examination of Butter and Its Adulterations—H. A. Weber,

Forms observed in Water of Lake Erie—C. M. Vorce, IV: 187.

Investigations Relating to Tea and its Adulterations—Thomas

scopic Organism in the Buffalo Water Supply and in Niagara River—

Mills, IV: 165, 281.

Examination of and Experiments with Glandular Secretions

to Method of Dr. Brown Sequard—George E. Fell, XI: 115.

Russsantion of Pork ty the Unied States Government, The—

Examination of Seminal Stains on Cloth, The—F. M. Hamlin,

Examination of Writing for the Detection of Forgery, Alters-

Exhibitions, IX: 311.

Light in Geological Darkness. President's Address—E. W.

214 INDEX TO VOLUMES I TO XXV

Milk Ducts, of Udder, Bacteria in, XX: 57.

Millen, J. C., Memoir of, XXV: 165.

Mills, Henry. Microscopic Organisms in the Buffalo Water kf

Niagara River, IV: 165, 281; Fresh-Water Sponge, (1 Plate), I

253; Thoughts on the Spongidae, VI: 131; Notes on the

Sponges, VIII: 132; Memoir of, XI: 152. q a

Minutes, I: 5; I: 17; II: 5; III: 5; IV: 3; V: 248; VI: pa I:

VIII: 204; IX: 334; X: 166; XI: 154; XII: 208; XIII: 176; XIV:

XV: 17; XVI: 1; XVII: 31; XVIII: 3; XIX: 190; XX: 347; XXI

XXII: 205; XXIII: 275; XXIV: 171; XXV: 167. of

Mirror, Concave, XIV: 43.

Missouri, Southwestern, Cave Salamander from, XXII: 189.

Mix, C. M. A Rapid Staining Apparatus, XX: 341.

Modern Conception of the Structure and Classification of Distoms, T

a Revision of the Tribes and a Rearrangement of the North . on

Genera—Chas. E. Bessey, XXI: 61. rh if

Modern Conception of the Structure and Classification of Desmids, T

a Revision of the Tribes, and a Rearrangement of the North /

Genera—Charles E. Bessey, (1 Plate), XXII: 89. 4

Modification of Some Standard Apparatus to Facilitate the Work of th

tologic and Embryologic Laboratory—Simon Henry Gage, XXII .

Modification of the Wenham half-disc illuminator, with an —— ;

ing—Robert Dayton, IV: 161.

Mole, Ending and Relation of Muscle Fibres, IX: 207.

Moody, Robert O. The Arrangement of the Muscular Layers of the ] ntest

of the Cat in the Region of the Juncture of the Large and § .

tines, (8 Plates), XIII: 120; A Study of the Muscular Tunic of the

and Small Intestines of Man in the Vicinity of the Caecum, ( 2 tes

XVI: 197; Memoir of Edward Waller Claypole, B.A., D.S., ae 269.

Moore, Allen Y., Memoir of, IX: 327. z

Moore, Veranus A. The Ammoniacal Fermentation of Urine, (a

XII: 97; An Apparatus for Holding Cover-glasses, (1 Plate), | TIT:

Observations on Staining the Flagella on Motile Bacteria, XI II

Contribution to the Study of the Myelin Degeneration of the P

Alveola Epithelium, (1 Plate), XV: 77; The Character of the F

Plate), XVI: 217; On the Flagella of Motile Bacteria, avis a

Hemospast. A New and Convenient Instrument for Daaae

Microscopic Examinations, XIX: 186; President’s Address:

in Disease, XX: 3; An Incubator for Student Use, (1 Plate), X

Mooted matter in the Use of an Eye-piece in Photo-

Clifford Mercer, XII: 50.

Morphogenesis and Histogenesis, Early, of the Liver in Sus ocd lor

including Notes on the Morphogenesis of the Ventral Pancreas—

Hilton, (4 Plates), XXIV: 55. : ie

Morphogenesis of the Stigmata and Stomata Occurring in Per

Vascular Endothelium, The—Arthur E. Hertzler, XXIII: 63.

Morphology of Rheumatic Blood—Ephraim Cutter, VI: 194.

INDEX TO VOLUMES I TO XXV 215

ing, Centering Block for, XVII: 373; Dry, V: 143; Hints on, VI: 209.

, Finishing and Preserving Slides—Frank L. James, VIII: 145.

Medi of High RerctveIndex—Hamiton South, Vi 86.

| Medium, New, VI: 186.

n we Table, New, XiV: 150.

=e 173; Solid, Cover-glass Sup-

, Ending and Relation of Muscle Fibres, IX: 207.

fe of, in Dog, XXV: 35; Structure of, in Lobster, IV: 131.

lar Coats, of Intestine of Cat, XIII: 120; of Intestines of Man, XVI:

7s Ocsophagus, X: 128

cle Fibres, Ending and Relation of, in Mouse, Mole, Bat and English

of Pulmonary Alveola Epithelium, XV: 77.

B.D. Picro-carmine and Alum-carmine as Counter Stains, XX: 337.

vm im Diseases, The. President’s Address—Veranus A. Moore, XX: 3.

¢ of Protozoa and Lesson of These Simplest Animals, The. President's

r David S. Kellicott, X: 6.

fr Cladocera of, XXII: 119; XXV: 45.

logy. Charles A. Spencer, A.M.; Charies H. Seckrider, MD.; dD. Cc

. M.D.; Edward B. Schickel, IV: 22; William B. Rezner, MD.,

: 242; Robert B. Tolles, VI: 41; Thad. S. Up de Graff, M.D., F.R.M.S.;

. N. Scatcherd, VII: 216; Rev. J. T. Brownell, A.M.; H. J. Rice,

ys 202; Allen Y. Moore, M.D.; Myron C. Davis, IX: 327;

| M. Kenyon, M.D.; Arthur M. Barker, M.D., X: 165; Boardman

Lambert Oviatt, B.S.; Henry Mills, XI: 151; Frisby T. Newcomer, M_D.,

MA, S.M., F.R.MS.; Eugene Pinckney, XII: 205; Forest W. Brayton,

M.D.; Hosmer Allen Johnson, M.D., XIII: 171; Thomas Hill Urquhart,

MD. Weld Fuller; Joseph Zentmayer; Dr. J. Gibbons Hunt, XIV:

. Francis Wolle; Dr. Edgar Alonzo Mundorff; Ezra Hollis

LM, XV: 245; Maitland L. Mallory, M.D., XVI: 248; James

Edmund Reeves, M.D.; Prof. Gustave Guttenberg, XVIII: 398; David

Simons Kellicott, B.Sc., B.Ph., Ph.D.; Wm. A. Rogers, A.M., Ph.D., LLD.;

Henry C. Coons, A.M., M.D., Ph.D., XX: a1; John Eugene Davies; Henry

216 INDEX TO VOLUMES I TO XXV

H. Doubleday; Albert E. Loveland, M.A., M.D.; Herbert R. Spencer, XXI:

249; Jacob Dolson Cox; Moses Clark White, A.M., M.D., XXII: 197;

Edward Waller Claypole, B.A. D.S., XXIII: 269; Chas. Marvin Vorce,

XXIV: 163; Richard L. Maddox, M.D., F.R.M.S.; Bushrod W. James,

A.M., M.D., LL.D.; Oscar C, Fox; J. C. Millen, M.D., XXV: 155.

Necturus, Blood of, XV: 39; Epithelium Lining the Mouth of, and Blood-

corpuscles of, VII: 126; Fat cells and Connective-tissue Corpuscles of, IV:

109; Histological Structure of Enteron of, XVI: 19.

Nematode, Cultural Studies of, XXIV: 8o.

Nerve Cells, Action of Electricity upon, XVII: 179.

Nerve Elements in Health and Disease, The—William C. Krauss, XVI: 234.

Nerves, Intramuscular Endings of, in Skeletal Muscles, XII: 132; of the Kid-

ney, V: 51; of Liver, IV: 95, 264; of the Lungs, III: 35.

Nerve Tissues, Formalin as Hardening Agent for, XVII: 315; Formalin for,

XVII: 319; Methods of Treating, XII: 116.

Nervous System of the Fresh-water Sponge, The—J. M. Stedman, XIII: 77.

Neurology, Formalin in, XVII: 319.

New American Microscopes, made by Bausch & Lomb Optical Co., Rochester,

N. Y.—Henry Bausch, XIII: 116.

New Apparatus for Photo-micrography, A—H. F. Atwood, VI: 176.

New Avian Cestode, A. Metroliasthes lucida—B. H. Ransom, XXI: 213.

New Clearer for Collodionized Objects, A—Pierre A. Fish, XV: 86.

Newcomer, F. S. Cleaning and Arranging Diatoms, VIII: 128.

Newcomer, Frisby T., Memoir of, XII: 205.

New Cover-slip Forceps, A—H. R. Gaylord, XVI: 123.

New Daphnella, A—C. M. Vorce, XII: 172.

New Fine Adjustment, A—E. H. Griffith, X: 161.

New Floscule, A—D. S. Kellicott, VII: 48.

New Freezing Microtome, A—Thomas Taylor, IV: 153.

New Form of Graphological Stand, A—M. D. Ewell, XIII: 69.

New Form of Life-slide, A—James H. Logan, VII: 110.

New Form of Microscope, A; Made by Bausch & Lomb Optical Co., Roches-

ter—W. A. E. Drescher, XI: 131.

New Form of Microscope Stand with Concentric Movements, A—Jacob D.

Cox, V: 147.

New Form of Section Cutter, On a—William A. Rogers, VI: 191.

New Genera and Species of North American Hydrachnidae—Robt. H. Wol-

cott, XXI: 177.

New Heliostat, A—Lyman S. Deck, XIII: 49.

New Hydra, A—M. J. Elrod and Maurice Ricker, XXIII: 257.

New Lens Holder—R. H. Ward, VI: 162.

New Method for the Quantitative Determination of Plankton Hauls, A—

Henry B. Ward, XVII: 255.

New Method for Securing Paraffin Sections to the Slide or Cover-glass, A—

Agnes M. Claypole, XVI: 6s.

New Method of Dry Mounting, A—Albert H. Chester, V: 143.

New Method of Making and Finishing Wax Cells, A—M. Pflaum, XVII: 374.

INDEX TO VOLUMES I TO XXv 217

: iiadior Medien, A-2i L. Seite, Vi: 186.

es A wane &. Preston, XIV: 150.

ew Pocket Polariscope, A—Oleomargariscope—Thomas Taylor, X: 159.

New Rotiferon, A—D. S. Kellicott, XI: 32.

ew Section Instrument for Vegetable Materials, A—Edson S. Bastin, XVI:

Species of Crenothrix (C. manganifera), A—D. D. Jackson, XXIII: 19.

w Way of Marking Objectives, A—William C. Krauss, XVII: 359.

ewts, Spermatheca and Fertilization in, XVII: 261.

ara River, Microscopic Organisms in, IV: 161.

ols Mary A. and Rowlee, W. W. Contributions to the Life-history of

™, foetidus, (2 Plates), XVII: 157.

Nitrite of Amyl, for Fine Injections, VIII: 140.

_ North American Species of Curvipes—Robt. H. Wolcott, XXIII: 201.

North American Species of Limnesia—Robt. H. Wolcott, XXIV: 130.

North American Species of the Genus Atax (Fabr.) Bruz., On the—Robert H.

Wolcott, XX: 193.

_ Note on a Microscope Presented by Linneus to Bernard Jussieu in 1738—

_ Jacob F. Henrici, IX: 214.

"Note on a New Rotifer—Gomphogaster Areolatus—C. M. Vorce, IX: aso.

Note on Argulus catostomi, A—D. S. Kellicott, VIII: 144.

_ Note on Microscopical Exhibitions—R. H. Ward, IX: 311.

_ Note on Resolution of Amphipleura pellucida by Central Light—Lyman

"Hotes on Colorado Entomostraca—Asthur E. Beardsley, XXIII: 41

| Notes on Color Protccoa with Description of New Speciee—Arthur

on Comparative Histology of Blood and Muscle—Edith J. Claypole,

Oxytnemogicbin Crystals, and the Collodion Method—Simon

: 79

Technique—Pierre A. Fish, XVIII: 287.

the of the United States—Francis Wolle, V: 137.

the Epithelium Lining the Mouth of Necturus and Menopoma, and

Blood-corpuscles of Necturus—Simon H. Gage, VII: 126.

the Fresh-water Sponges—Henry Mills, VIII: 132.

the Isolation of the Tissue Elements—Simon H. Gage, XIX: 170.

the Parasites of the Lake Fish—Henry B. Ward, XXII: 175.

the Structure, Development, and Position, of an undescribed Flagel-

fusorian—J. H. Fisher, II: 44.

the Structure of the Moth Attacus Cecropia—H. N. Lyon, XI: 13s.

Two Parasites of the Cray-Fish—D. S. Kellicott, V: 115.

Some Undescribed Infusoria, from the Infusorial Fauna of Louis-

. C. Smith, XIX: gs.

iit oat

“4 ba thc) ae thn va

3 Fee | i ie

a ~ 7 core it

218 INDEX TO VOLUMES I TO XXV

Notices of Some Undescribed Infusoria, from the Infusorial Fauna of

Louisiana—J. C. Smith, XX: 51.

Notices of Some Undescribed Infusoria, from the Infusorial Fauna of Louke-

iana—J. C. Smith, XXI: 87.

Notogonia ehrenbergii Perty—J. C. Smith, (1 Plate), XXI: gs.

Numerical Aperture—Marshall D. Ewell, XIV: 44

Numerical Aperture of an Objective in Relation to its Angle of Aperture in

Air, Water and Balsam, The—H. J. Detmers, VII: 199.

Obituary Notices. (See Necrology.)

Objectives, XII: 35; Amplifying Power of, XI: 22; An Improvement in, VI:

148; Homogeneous-immersion, III: 62; Immersion, VII: 51; Magnifying

Power of, VI: 183; Marking, XVII: 359; Penetration in, II: 70; Selection

of a Series of, V: 33; Systematic Examination of, I: 62; Universal Screw

for, VI: 153.

Observations on Fresh-water Infusoria—D. S. Kellicott, X: 97.

Observations on Infusoria, with Descriptions of New Species—D. S. Kellicott,

VI: 110.

Observations on Lerneocera cruciata—D. S. Kellicott, I: 64.

Observations on Some Fresh-water Infusoria. With Descriptions of a Few

Species Regarded as New—D. S. Kellicott, VII: 38.

Observations on Staining the Flagella on Motile Bacteria—Veranus A. Moore,

XIII: &s.

Observations on the Fat cells and Connective-tissue Corpuscles of Necturus

(Menobranchus)—Simon H. Gage, IV: 109.

Occurrence of Albino Eggs of the Spotted Salamander, Amblystoma punc-

tatum L., An—Horace W. Britcher, XX: 69.

Occurrence of Gregarina in the American Lobster, On the—Albert H. Tuttle,

III: 47.

Occurrence of Haemosporidia in the Blood of Rana Catesbiana, Upon the,

with an Account of their probable Life History—Jas. H. Stebbins, Jr.,

XXV: 55.

Oculars, Amplifying Power of, XI: 22; Report of Committee on, VI: 228.

Oertel, T. E. Method for Preparing Nucleated Blood in Bulk for Class

Demonstration, XX: 49.

Ocsophagus, Muscle Coats of, X: 128. ,

Oil-sectioning, with Collodion, XVII: 361.

Old Microscope of the Culpeper Type, An—J. F. Henrici and C. C. Mellor,

X: 140.

Oleomargariscope, X: 159.

Optical Errors and Human Mistakes—Ernst Gundlach, VIII: 157.

Organs of Taste, XIX: 129.

Original Method of Staining and Mounting Pollens—J. T. Brownell, VI: 212.

Osmic Acid.—Its Uses and Advantages in Microscopical Investigations—

Thomas B. Redding, IV: 183. q

Outline of the Tube Plan of Structure of the Animal Body—J. S. Foote,

XXV: 63.

a ee ee aR 219

BL Method of Sectioning Cartilage Fresh, By Partial Embedding,

> 142; Cardiac Muscle Cells in Man and Certain Other Mammals, IX:

3 Memoir of, XI: 151.

and Sargent, E. H. Use of Nitrite of Amyl for Fine Injections,

of Cicada septendecim, XVII: 111.

Dissolved in Nataral Waters, Efect of on Microscopic Organism

Crystals, XIII: 70.

B. L. and

—,

‘Palate, Soft, Comparative Study of, XXI: 41; of Cat, X: 58

Pancreas, Ventral, Morphogenesis of, in Pig, XXIV: 55.

! Crustaceous, of “ Miller's Thumb” (Cottus), XIV: 76; of Human

ia “Ear, XXII: 81.

_ Parasites, Animal, Determination of the Number of in Meat, IX: 191; Crus-

__— taceous, on Fresh-water Fishes, IV: 75; of Common Fowl, V: 131; of the

_ __—*Cray-fish, V: 115; of Lake Fish, XV: 173; of Lake Fish, XXII: 175.

Parasites of the Lake Fish, On the—Henry B. Ward, XV: 173.

_ Parasitism of Epiphegus Virginiana—Hermann Schrenk, XV: 91.

_ Parker, Frank J. Micrometry of Human Red Blood Corpuscles, XX: 41

_ Parker, Horatio N. Sates Kedvcbinges of Wiad Weck en’ Sertice’ Wiis

Supplies, XXII: 13.

_ Parker, Horatio N. and Whipple, Geo. C. On the Amount of Oxygen and

Carbonic Acid Dissolved in Natural Waters and the Effect of these Gases

spon the Occurrence of Microscopic Organisms, (4 Plates), XXIII: 103.

Partial List of Rotifera of Shiawassee River at Corunna, Michigan—D. S.

Bt Misstration in Objectives. Is it 2 Defect or an Advantage?—C. M. Voree,

ie i: 7a

Pennock, Edward, Two Very Simple Microtomes, XIX: 189.

__ Peple, G. A. Memoir of Dr. Wm. R. Weisiger, VI: 250.

Peritoneal and Vascular Endothelium, The Morphogenesis of the Stigmata

__—s and Stomata occurring in—Arthur E. Hertzler, XXIII: 63.

Peritoneal Epithelium of Some Ithaca Amphibia, The—Isabella M. Green,

Perry, Stuart H. Rhizopods of Oakland Co., Mich. XIT: 94.

__ Persistence of Bacteria in the Milk Ducts of the Cow's Udder, The—Archi-

bald R. Ward, XX: 57

at tas

220 INDEX TO VOLUMES I TO XXV

Pflaum, Magnus. Report of the Treasurer, XVI: 18; Report of Treasurer,

XVII: 94; Some Notes on Alleged Meteoric Dust, XVII: 95; A Metal

Centering Block for Mounting, XVII: 373; A New Method of Making and

Finishing Wax Cells, XVII: 374; Treasurer’s Report, XVIII: 46; Treas-

urer’s Report, XIX: 194; Memoir of Gustave Guttenberg, Ph.D., XVIII:

308; Treasurer’s Report, XX: 353; Report of Custodian, XXV: 172. -

Phagocytic Action, in Amphibia and Mammalia, XIX: 93.

Phanerogams, Aération of Organs and Tissues in, XV: 143.

Photographing with High Powers by Lamplight—H. J. Detmers, X: 143.

Photographic Apparatus, Laboratory, XXIII: 263.

Photography, Apparatus for use with Oblique Illumination, X:155; as an

Aid to Microscopical Investigations, I: 59; Astronomical, XVIII: 132;

with High Powers by Lamplight, VI: 99; with High Powers by Lamplight,

a? 143

Photography as an Aid to Microscopical Investigations—Carl Seiler, I: 59.

Photography with High Powers by Lamplight: Illustrating Structure of

Diatoms—Jacob D. Cox, VI: 99.

Photomicrograph versus Microphotograph—A. Clifford Mercer, VIII: 131.

Photomicrograph versus Microphotograph—A. Clifford Mercer, XVIII: 131.

Photomicrographs by Gas-light—Geo. M. Sternberg, XIV: 8s.

Photo-micrography, XVII: 340; XVIII: 107; Acetylene Gas as Illuminant in,

XVIII: 136; by Gas-light, XIV: 85; A Handy Camera, XII: 69; Heliostat

for, VII: 103; High-power, Best Technique for, XI: 112; Lantern Slides

and Apparatus, XIV: 141; New Apparatus for, VI: 176; New Camera for,

IX: 263; Stereoscopic, with High Powers, XXIV: 23; Systematic, XVIII:

117; Theory and Practice of, IX: 263; Use of an Eye-piece in, XII: 50;

Use of Apparatus in Astronomical Photography, XVIII: 132; with Dry-

Plates and Lamp-Light, V: 59; with Opaque Objects, XX: 189.

Photomicrography—Thomas J. Bray, XVIII: 107.

Photomicrography with Opaque Objects—W. H. Walmsley, XX: 189.

Photo-spectrography of Colored Fluids—Moses C. White, XXII: 99.

Phycomycetes, Structure and Classification of, XXIV: 27.

Physician and His Microscope, The—A. A. Young, XVIII: 71.

Physiology, of the Human Brain, V: 141.

Picric and Chromic Acid for the Rapid Preparation of Tissues for Classes in

Histology—Simon H. Gage, XII: 120.

Picro-Carmine and Alum-Carmine as Counter Stains—B. D. Myers, XX: 337.

Pig, Morbid Growth in Stomach, V: 125; Morphogenesis and Histogenesis

of Liver and Morphogenesis of Ventral Pancreas, XXIV: 55.

Pinckney, Eugene, Memoir of, XII: 207.

Plankton Hauls, Quantitative Determination of, XVII: 255.

Plankton, Measurement of, XXI: 227.

Plankton of Echo River, Mammoth Cave, The—Charles A. Kofoid, XXI: 113.

Plankton of Lake Maxinkuckee, Indiana, The—Chancey Juday, XXIII: 61.

Plant Decay, Nematode associated with, XXIV: 89.

Plants, Microscopic, Evolution in, XXIV: 5s.

es ee, ae

INDEX TO VOLUMES I TO XXV 221

Plea for Systematic Instruction in the Technique of the Microscope at the

_ University, A. President’s Address—Jacob D. Cox, XV: 1.

Plea for the Study of Limnobiology, A—Henry B. Ward, XXI: 201.

nee ay Ae Lame XY:

“tal Boboning, Crane Leds Microscopical Antony in XI: 110,

4 Oleomargariscope, X: 159.

Dried Beef—H. J. Detmers, VII: 54.

ee es), Demee 212.

___ Pollen tubes Again—John Kruttschnitt, VII: 62.

Pollution, of Rivers, and Purification, XXV: 105.

____ Polyzoa—Observations on Species detected near Buffalo, N. Y.—D. S. Kelli-

Examination of, XIII: so.

Roscoe. An Addition to the Parasites of the Human Ear, (1 Plate),

: 81.

oy Nomaggy gare tg gala mma IV: 127.

Preparing and Mounting Bacteria—T. J. Burrill, V: 79.

Preparation and Imbedding the Embryo Chick—Simon H. Gage and Grant S.

Preparation and Mounting of Brain Sections—Theodore Deecke, IV: 275.

____ Preparation and Mounting of Double Stainings—C. C. Merriman, I: 71.

_ Preparation and Mounting of Foraminifera, with Description of a New Slide

for Opaque Objects, The—F. M. Hamlin, V: 6s.

of Chick Embryos for Microscopical Examination, On the—W.

Preservation, of tissues Isolated by Means of Caustic Potash or Nitric Acid,

XI: 3%

_ President, Annual Address of—R. H. Ward, I: 35; Hamilton L. Smith,

It: 17; George E. Blackham, IV: 25; Albert McCalla, V: 1; Jacob D. Cox,

VI: 5; Hamilton L. Smith, VII: 5; Thomas J. Burrill, VIII: 5; William

A. Rogers, IX: 5; David S. Kellicott, X: 6; William J. Lewis, XI: 5;

George E. Fell, XII: 1; Frank L. James, XIII: 1; Marshall D. Ewell,

XIV: 1; Jacob D. Cox, XV: 1; Simon H. Gage, XVII: 3; A. Clifford

Mercer, XVIII: 321; E. W. Claypole, XIX: 3; Veranus A. Moore, XX: 3;

Wm. C. Krauss, XXI: 1; A. M. Bleile, XXII: 1; Carl H. Eigenmann,

——— - ae _

“ 2, ax. “

ee a PN :

- : . ae? ce

eeu! Bain ths, Mas di

ae ie |

(a |) a ne “

ia ae 4 % \ one 7 a

___—sOXXIIT: 5; Charles E. Bessey, XXIV: 5; E. A. Birge, XXV: 5.

___ Preston, William N. A New Mounting Table, XIV: 150.

i r Preston, William N. A Practical Drying Oven, XIV: 152.

222 INDEX TO VOLUMES I TO XXV

Prevention of the Pedetic or Brownian Movement in Milk or other Liquids

with Minute Objects in Suspension—Simon H. Gage, XXIV: 22.

Processes of Life Revealed by the Microscope, The; a Plea for Physiological

Histology. President’s Address—Simon H. Gage, XVII: 3.

Production of Citric Acid by Fermentation, On the—Wm. H. Seaman,

XV: 90.

Projection apparatus, for Use with Oblique Illumination, or Opaque objects,

X: 155.

Protophyta, Classification of, XXV: 8o.

Protoplasm, Influence of Electricity on, XII: 1.

Protozoa, Nature of, X: 6; of Colorado, XXIII: 49.

Public Water Supply for Small Towns—M. A. Veeder, XVIII: 176,

Punches, for Sheet Wax, VI: 215.

Purification of polluted Rivers, XXV: 105.

Purification of Water by the Alum Method, XV: 211.

Question of Correct Naming and Use of Micro-reagents, The—V. A. teas

XVII: 350.

Questions in Regard to the Diphtheria Bacillus—M. A. Veeder, XX: 81.

Rabbit, Egg-like Bodies in Liver of, V: 167.

Radiation of Heat between Metals, with Numerical Results for Brass and for

Steel, On the—W. A. Rogers, X: 33.

Rafter, Geo. W. On the Use of the Amplifier, with Observations on the

Theory and Practice of Photo-micrography, suggested by the Design of a

New Photo-Micro-Camera, IX: 263; On the Best Technique for High-

power Photo-micrography, XI: 112.

Ransom, B. H. A New Avian Cestode—Metroliasthes lucida, (2 Plates),

XXI: 213; On Hymenolepis carioca (Magalhaes) and Hymenolepis

megalops (Nitasch) with Remarks on the Classification of the Group, (3

Plates), XXIII: 151.

Ranunculaceae, Structure of Fruit of, XVI: 69.

Rapid Section Cutting—James E. Whitney, VII: 122.

Rapid Staining Apparatus, A—C. M. Mix, XX: 341.

Reaction of Diabetic Blood to Some of the Anilin Dyes, The—V. A. Latham,

XXI: 31.

Reagents, Naming and Use of, XVII: 350; Plea for Study of, XV: 209.

Red Blood Corpuscle in Legal Medicine—Moses C. White, XVIII: 201.

Redding, Jacob. Muscular Contractility, (1 Col. Plate), III: 17; Osmic

Acid.—Its Uses and Advantages in Microscopical Investigations, IV: 183.

Redding, J. The Extra-vascular Circulation, VI: 8.

Reed, Raymond C. Dahlia as a Stain for Bacteria in Sections eut by the

Collodion Method, XIX: 182.

Reeves, James Edmund, Memoir of, XVIII: 397.

Reference Model, A—Susannah Phelps Gage, XIV: 154.

Refractive Index, of Immersion Fluids, VII: 83.

Regeneration of the Intestinal Epithelium in the Toad (Bufo lentiginosus

americanus) during Transformation, The—B. F. Kingsbury, XX: 45.

INDEX TO VOLUMES I TO XXV 223

a a aulict vires Gta of OO

_ jectives, The—George E. Blackham, V: 33.

SENINIE Gt the Microactys to the Administration of Jasticn, The President's

_ Address—Marshal! D. Ewell, XIV: 1.

Remarks on a Device for Enabling two Observers to View Objects Simul-

_ taneously—James H. Logan, VII: 120.

_ Remarks on Stephanodiscus Niagarae—C. M. Vorce, VII: 139.

_ Remarks on the Fasoldt Test-plate—R. H. Ward, IX: 318

Remarks on the Methods of Making Microscopical Societies Successful—R.

HL Ward, VIII: 94

Reply to Professor Weber—Thomas Taylor, VIII: 116.

Memoir of, VIII: 203.

_ Ricker, Maurice and Elrod, M. J. A New Hydra, XXIII: 257.

and Purification—T. J. Burrill, XXV: 10s.

Robert B. Tolles and the Angular Aperture Question. President's Address—

Jacob D. Cox, VI: s.

_ Rogers, William A. On the Conditions of Success in the Construction and

the Comparison of Standards of Length, IV: 231; V: 240; A Critical Study

of the Action of a Diamond in Ruling Lines upon Glass, V: t49; A Study

of the Centimeter, Marked “A,” Prepared by the U. S. Bureau of Weights

and Measures for the Committee on Micrometry, V: 184; On a New Form

224 INDEX TO VOLUMES I TO XXV

of Section Cutter, VI: 191; Determination of the Absolute Length of Eight

Rowland Gratings at 62° Fahr., VII: 151; Methods of Dealing with the

Question of Temperature in the Comparison of Standards o

67; President’s Address: The Microscope as a Factor in a Study of the

Behavior of Metals under Variations of Temperature, IX: 5; On the

Radiation of Heat between Metals, with Numerical Results for Brass and

for Steel, X: 33; A Practical Method of Securing Copies of the Standard

Centimeter Designated “Scale A,” XI: 109; Report on Standard Centi-

meters, XIII: 207; The Microscope in the Workshop, XIV: 128; A Word

Concerning Filar Micrometers, XIV: 132; A Practical Method of Referring

Units of Length to the Wave Length of Sodium Light, (1 Plate), XVII:

305; Memoir of, XX: 25.

Roots, Modifications of, XVII: 98

Ross, Mary J. Special Structural Features in the Air-sacs of Birds, (3

Plates), XX: 29.

Rotifera, A New Species, XI: 32; a New Species, IX: 250; Certain Species

of, IX: 181; Notes on, VI: 126; of Sandusky Bay, XVIII: 155; XIX: 43;

of Shiawassee River, Michigan, X: 84; New Species from Louisiana,

XXV: 121.

Rotifera of Sandusky Bay—D. S. Kellicott, XVIII: 155.

Rotifera of Sandusky Bay, The. (Second Paper)—D. S. Kellicott, XIX: 43.

Rowlee, Willard W. Imbedding and Sectioning Mature Seeds, XII: 113;

Structure and Development of Buds in the Leaf of Bryophyllum calycinum,

Salisb., (2 Plates), XIV: 80; The Aeration of Organs and Tissues in

Mikania and other Phanerogams, (6 Plates), XV: 143; The Chlorophyll

Bodies of Chara Coronata, XVII: 155.

Rowlee, W. W. and Nichols, Mary A. Contributions to the Life-history of

Symplocarpus Foetidus, (2 Plates), XVII: 157.

Rules for the Control of the Standard Micrometer, V: 200.

Sackrider, Charles H., Obituary notice of, IV: 22.

Salamander, New Cave, XXII: 189; Spotted, Albino Eggs of, XX: 60.

Salamanders, Spermatheca and Fertilization in, XVII: 261.

Sandusky Bay, Rotifera of, XVIII: 155; XIX: 43.

Sarcina ventriculi in Medico-legal Investigation of Blood Stains—W. N.

Sherman, XV: 136.

Sargent, E. H. The Meibomian Glands in the Cat.—Note, VIII: 143.

Sargent, E. H. and Oviatt, B. L. Use of Nitrite of Amyl for Fine Injections,

VIII: 140.

Scales, of Seira buskii and Lepidocyrtus curvicollis, XVIII: 194.

Scatcherd, James N., Obituary notice of, VII: 223.

Schaufelberger, F. J. Memoir of Thomas Hill Urquhart, M.D., XIV: 159.

Schickel, Edward B., Obituary notice of, IV: 23.

Schrenk, Hermann. Parasitism of Epiphegus Virginiana, (10 Plates), XV:

91; Some Modifications of Stems and Roots for Purposes of Respiration,

(3 Plates), XVII: 98.

Science Studies, Influence of, VII: s.

ht INDEX TO VOLUMES I TO XXV 225

” ‘Seaman, William H. A College Microscope, XII: 67; On the Luminous

463; Report of Treasurer, XIV: 36; An Early American Microscope, XIV:

_ 4§6; Memoir of Dr. J. Gibbons Hunt, XIV: 166; On the Production of

___ Citric Acid by Fermentation, XV: 90; Some Notes on Formalin, XVI: 238;

_ Memoir of James Edmund Reeves, M.D., XVIII: 397; Memoir of Henry

"5 ae 250; Memoir of Oscar C. Fox, XXV: 163.

orm of, VI: 191.

VI: 171.

VIL: 122.

Seeds, Nature, Imbedding and Sectioning, XII: 113.

_ Seiler, Carl. Photography as an Aid to Microscopical Investigations, I: 59;

Reference to Glycerine and Balsam, II: 60.

_ Seira buskii, Scales of, XVIII: 194.

_ Seminal Stains, Microscopical Examination of, on Cloth, V: 21.

_ Sense Organs, Lateral Line System of, in Amphibia and Dipnoans, XVII:

rome 3

Serial Sections—S. H. Gage, VI: 202.

Series of Lantern Slides of Photomicrographs and Photomicrographic Ap-

A—A. Clifford Mercer, XIV: 141.

ral New Microscopical Accessories, On—E. H. Griffith, VIII: 150.

F .

Cladodont, Teeth of, XVI: ror.

James B. Systematic Photomicrography and Apparatus Pertaining

‘

W. N. Sarcina ventriculi in Medico-legal Investigation of Blood

Stains, XV: 136.

Should Homogenous-immersion Objectives be made adjustable or non-adjust-

able?—Geo. E. Blackham, III: 62.

_ Shrinkage of Cement-cells the Cause of Leakage and Creeping in Glycerin

Mounts—Frank L. James, IX: 173.

Shurley, E. L. An Improved Slide for the Examination of Gaseous Matter,

III: 6s.

Sierras, the, Biological Reconnoissance of some Elevated Lakes in, XXV: 127.

___ Silver, Deposition of on Glass and other Non-metallic Surfaces, VI: 71.

____— Simple and Efficient Deposit-glass, A—George E. Fell, XI: 139.

Simplification of Laboratory Methods—William C. Krauss, XVI: 119.

Slide, for Opaque Objects, V: 65; Ideal, VI: 179; Securing Paraffin Sections

to, XVI: 6s.

Slides, Collection of, IX: 322; Indexing, Cataloguing, Preparing and Ar-

ranging, XXI: 127; List of, VII: 214; Mounting, Finishing and Preserving,

)

Le ee ate

+ Pyne ote ae

226 INDEX TO VOLUMES I TO XXV

Slide Cabinets, Construction of, VII: 108.

Slide-catalogue, Microscopical, IX: 233.

Smith, Hamilton L. President’s Address: Deep Sea Soundings and the nei

fluence of Microscopical Algae on Deep Sea Life, with a few Remarks on

Evolution, II: 17; Memoir of Charles A. Spencer, (Portrait p. 1), IV: 22;

Rhizosolenia gracilis, n. sp., 1V: 177; A New Mounting Medium, VI: 186;

President’s Address: The Unconscious Influence of Science Studies, VII:

5; Device for Testing Refractive Index of Immersion Fluids, VII: 83;

Mounting Media of High Refractive Index, VII: 86; A Contribution to the

Life History of the Diatomaceae, (5 Col. Plates), VIII: 30; Contribution

to the Life History of the Diatomaceae,—Part IL., (6 Col. Plates), IX: 126.

Smith, J. C. Notices of Some Undescribed Infusoria, from the Infusorial

Fauna of Louisiana, (2 Plates), XIX: 55; The Sporular Development of the

Amoeba villosa, Leidy, XIX: 69; Notices of Some Undescribed Infusoria,

from the Infusorial Fauna of Louisiana, (1 Plate), XX: 51; Notices of

Some Undescribed Infusoria, from the Infusorial Fauna of Louisiana, (1

Plate), XXI: 87; Notogonia ehrenbergii Perty, (1 Plate), XXI: 95;

Treasurer's Report, XXI: 263; Report of Treasurer, XXII: 209; Treas-

urer’s Report, XXIII: 281; Treasurer's Report, XXIV: 178; Synchaeta

bicornis: A New Rotifer from the Brackish Waters of Lake Pontchartrain,

Louisiana, XXV: 121; Report of Treasurer, XXV: 173.

Smuts, X: 45.

Soft Palate in the Domestic Cat, The—T. B. Stowell, X: 58.

Soiree, Annual, V: 201; in connection with the Rochester Academy of Sci-

ences, VI: 234; XIV: 29.

Solution of the Eel Question, The. President’s Address—Carl H. Eigen-

mann, XXIII: 5.

Some Advantages of Field Work on Surface Water Supplies—Horatio N.

Parker, XXII: 13.

Some Diatom Hoops. The Question of their Mode of Growth (Aulacodiscus

Kittoni)—Jacob D. Cox, VII: 33.

Some Infusoria Found on the Cray-Fish, On—D. S. Kellicott, V: 105.

Some Laboratory Apparatus—Simon Henry Gage, XXI: 107.

Some Medico-legal Aspects of Trauma in Relation to Diseased Cerebral

Arteries. President’s Address—Wm. C. Krauss, XXI: 1.

Some Methods of Histologic Technique—J. Melvin Lamb, XVIII: 2or.

Some Methods of Treating Nerve Tissues—William C. Krauss, XII: 116.

Some Modifications of Stems and Roots for Purposes of Respiration—Her-

man von Schrenk, XVII: 98.

Some New and Improved Apparatus—E. H. Griffith, VII: 112.

Some New and Rare Infusoria—D. S. Kellicott, IX: 187.

Some New Points in Photo-micrography and Photo-micrographic Cameras—

W. H. Walmsley, XVII: 340.

Some Notes on Alleged Meteoric Dust—Magnus Pflaum, XVII: 95.

Some Notes on Formalin—Wm. H. Seaman, XVI: 238.

Some Notes on the Innervation of the Lungs—A. M. Bleile, III: 35.

INDEX TO VOLUMES I TO XXV 227

capaho Destruction Powers of Cartaia Tasees~C. 0.

ee ae eb hensande

. D. Hyatt, XVIL: a1.

Points in the Structure of the Acanthocephala—H. W. Graybill, XXIII:

EL yn <a suenesuts mucciiee an Wor ces

ee cece eetne-e: W. Alleger, XVI: 101.

eeemeseeier, VIE: 174

English, Ending and Relation of Muscle Fibres, IX: 207; Brain of,

t, Thomas B. A Comparison of the External and Middle Ear of Man

id the Cat, XII: 146.

tr, Debt of American Microscopy to, XXIII: 19.

- + Charles A., Obituary notice of (with Portrait), IV: 22.

cet ee ee eee

ncer-Tolles Fund, Report of, VII: 249; IX: 326; a oe XIII: 209;

XIV: 36; XV: 343 XVI: 18; XVII: o4; XVIII: 47; XIX: mee

eee mae 282; ‘XXIV: 179; XXV: 172.

Spines, Paleozoic, XVIII: 151.

Sponges, Fresh-Water, IV: 209, 253; Fresh-water, VIII: 132; Fresh-water,

im the Water Supply of Cities—J. D. Hyatt, IV: 197.

_Sporular Development of the Amoeba villosa, Leidy, The—J. C. Smith,

XIX: 1&2.

: 341; Hints on, VI: 209; of Tissues Isolated by

or Nitric Acid, XI: 34.

ter of Histological Elements Isolated by

: Potash (KOH) or Nitric Acid (HNO,)—Simon H. Gage

lies: Dothla; Peiparetion ond: Mounting of, I: 71.

Stains, Counter, XX: 337; Use of, especially in Differential Diagnosis, XIIT:

Oe 4

‘Stand, Zentmayer’s American-continental, XIV: 48.

Standard Glass and Speculum Metal Centimeters—M. D. Ewell, XIII: 71.

228 INDEX TO VOLUMES I TO XXV

Standards of Length, Construction and Comparison of, IV: 231; V: 240;

Temperature in Comparison of, VIII: 67.

Stebbins, Jas. H., Jr. Upon the Occurrence of Haemosporidia in the Blood

of Rana Catesbiana, with an Account of their probable Life History, (2

Plates), XXV: 55.

Stedman, J. M. The Tape Worm. Methods of Preparation for the Museum

and the Microscope, IX: 243; On the Development and a Supposed New

Method of Reproduction in the Sun-Animalcule—Actinospharium Eich-

hornii, (1 Plate), X: 107; Researches on the Anatomy of Amphistomum

Fabaceum Diesing, (3 Col. Plates), XI: 85; Killing of Invertebrata in an

Expanded and Natural Condition, XIII: 73; The Nervous System of the

Fresh-water Sponge, XIII: 77.

Steel, Micro-Structural Characteristics of, XIX: 28.

Stems, Modifications of, XVII: 98.

Stephanodiscus Niagarae, VII: 139.

Stereoscopic Effects obtained by the High-power Binocular Arrangement of

Powell & Lealand—A. Clifford Mercer, IV: 127.

Stereoscopic Photomicrography with High Powers—F. E. Ives, XXIV: 23.

Sternberg, Geo. M. Photomicrographs by Gas-light, (1 Plate), XIV: 8s.

Stigmata, of Endothelium, XXIII: 63.

Stomach, of Amia calva, Structure of, XII: 16s.

Stomach, of Pig, Morbid Growth in, V: 125.

Stomata, of Endothelium, XXIII: 63.

Stowell, T. B. The Soft Palate in the Domestic Cat, X: 58.

Stratton, S. W. and Burrill, T. J. A Heliostat for Photo-micrography, VII:

103.

Structure and Classification of the Conjugatae, The, with a Revision of the

Families and a Rearrangement of the North American Genera—Chas. E.

Bessey, XXIII: 145.

Structure and Classification of the Phycomycetes, The, with a Revision of the

Families and a Rearrangement of the North American Genera—Chas. E.

Bessey, XXIV: 27.

Structure and Development of Buds in the Leaf of Bryophyllum calycinum,

Salisb—W. W. Rowlee, XIV: 80.

Structure of Some Paleozoic Spines from Ohio, On the—E. W. Claypole,

XVIII: 151.

Structures of the Bone of Dinichthys—E. W. Claypole, XV: 189.

Structure of the Diatom Valve, The—R. P. H. Durkee, VI: 105.

Structure of the Fruit in the Order Ranunculaceae, The—Karl McKay

Wiegand, XVI: 60.

Structure of the Muscles of the Lobster—M. L. Holbrook, IV: 131.

Structure of the Stomach of Amia calva—Grant S. Hopkins, XII: 165.

Structure of the Teeth of the Devonian Cladodont Sharks, On the—E. W.

Claypole, XVI: 191.

Studies of the Development of Cartilage in the Embryo of the Chick and Man

—M. L. Holbrook, VII: 76.

Studies on the Genus Cittotaenia—Rufus Ashley Lyman, XXIII: 173.

INDEX TO VOLUMES I TO Xxv 229

es Me pices Cobia, tn: ws

cat 6 ge inggalag acs

bicornis : A New Rotifer from the Brackish Waters of Lake Pont-

Louisiana—J. C. Smith, XXV: 121.

fd Sa Methods of Preparation for the Museum and the Micro-

scope—J. M. Stedman, IX: 243.

_- Taste, Organs of, XIX: 129.

_ Taylor, Thomas. A New Freezing Microtome, IV: 153; Internal Parasites

___ im the Common Fowl, V: 131; Butter and Fats. To Distinguish One Fat

from Another by Means of the Microscope, (1 Col. Plate), VII: 128; Reply

Ee Professor Weber, (1 Plate), VIII: 116; The Crystallography of Butter

and Other Fats, (6 Plates), IX: 315; A New Pocket Polariscope—Oleo-

‘ey margariscope, X: ee ene erence

Bp Aeeations, (8 Plates), XI: 46,

wa Teaching Microscopical ma Ba in Medical Schools, XVIII: 311.

Technique, Histologic, XVIII: 291; Methods in, XIX: 175; Notes on, XVIII:

Teeth of Devonian Cladodont Sharks, XVI: 19t.

‘Teeth of Mazodus, On the—E. W. Claypole, XVIII: 146.

‘Temperature, in Comparison of Standards of Length, VIII: 67.

‘Termination of the Nerves in the Kidney, The—M. L. Holbrook, V: 51.

‘Termination of the Nerves in the Liver, The—M. L. Holbrook, IV: 95, 264.

‘Tetanus, Micro-Organiams in Blood of a case of, IV: 157.

_—s- ‘Texas, Subterrancan Fauna of, XXIII: &3.

Textile Fabrics, Investigation of Burns and Scorches on, XTIT: 1.

___Thermocline, The, and its Biological Significance—E. A. Birge, XXV: 5.

“oa 16

2 ene.

230 INDEX TO VOLUMES I TO XXV

Thomas, Mason B. Collodion Method in Botany, XII: 123.

Thornbury, Frank J. The Increasing Pollution of our Municipal Water-sup-

plies, XVIII: 182,

Thoughts on the Spongide—Henry Mills, VI: 131.

Three New Accessories for the Microscope—E. H. Griffith, XIII: 47.

Tissue Elements, Isolation of, XIX: 179.

Tissues, Isolated by Means of Caustic Potash or Nitric Acid, Staining and

Permanent Preservation of, XI: 34; Rapid Preparation of, XII: 120.

Toad, Regeneration of Intestinal Epithelium in, XX: 45.

Tolles, Robert B. and the Angular Aperture Question, VI: 5; Debt of

American Microscopy to, XXIII: 19; Elected an Honorary Member, VI:

253; Memoir of (with Portrait), VI: 41.

Tolman, Henry L. Hints on Expert Testimony, XIII: 64.

Treasurer's Report, II: 80; III: 97; IV: 286; V: 219; VI: 282; VII: a13

VIII: 198; IX, 324; XI: 142; XII: 252; XIII: 209; XIV: 36; XV: 34

XVI: 18; XVII: 94; XVIII: 46; XIX: 1904; XX: 353; XXI: 263; XXII

209; XXIII: 281; XXIV: 178; XXV: 173.

Trichinez, Determination of the Number of in Meat, IX: rot.

Tube-length, Report of Committee of the American Society of Microscopists

on Uniformity of, XII: 250.

Tuberculosis, Limitation of, XVI: ror.

Tumor of the Left Auricle—D. N. Kinsman, III: 29.

Tumors, Diagnosis of, XIV: 71; Malignant, Relation of Yeasts to, XVIII:

119.

Turn-table, Brownell, VI: 173.

Turn-tables, Griffith’s, VI: 16s.

Turtle, Soft-shelled, Brain of, XVII: 18s.

Tuttle, Albert H. On the Occurrence of Gregarina in the American Lobster,

Ill: 47.

Two Growths of Chlamydomonas in Connecticut—Fred’k S. Hollis, XXIV: 13.

Two New Combined Inverted and Vertical Microscopes—Edward Bausch,

VIII: 148.

Two New Forms of Stage Micrometers—M. D. Ewell, XII: 76.

Two Very Simple Microtomes—Edward Pennock, XIX: 189.

Typhoid Fever, Bacteria in Ice, Relation to, XI: 70.

Typhlomolge rathbuni Stejneger, Eyes of, XXI: 49.

Udder, Bacteria in Milk Ducts of, XX: 57.

Ulrich, Carl Jost. A Contribution to the Subterranean Fauna of Texas (5

Plates), XXIII: 83.

Unconscious Influence of Science Studies, The. President’s Address—Ham-

ilton L. Smith, VII: 5s.

United States, Desmidix of, V: 137.

Universal Screw for Microscope Objectives, The—Edward Bausch, VI: 153.

Up de Graff, T. S. Descriptions of Certain Worms, V: 117; Memoir of, VII:

216.

Uredinex of Illinois, The—A List of the Species—T. J. Burrill, VII: 93.

INDEX TO VOLUMES I TO XXV 231

ine, Acid, Effect of Dilute Solutions, upon Red Blood Corpuscles, XV: 129;

phmmonincal Fermentation of, XI: 97. et

phar pe beng abel

of the Amplifier, with Observations on the Theory and Practice of

er. suggested by the Design of a New Photo-Micro-

Camera, On the—Geo. W. Rafter, IX: 263.

e oO Cells in Connection with White Zinc Cement for Fluid Mounts,

H. Walmsley, Il: 63.

Smuts, The; with a List of Illinois Species—T. J. Burrill,

te A. Public Water Supply for Small Towns, XVIII: 176; Ques-

__ tion in Regard to the Diphtheria Bacillus, XX: 81; Defective Development

; and Disease, with Special Reference to the Curability of Consumption and

XXI: 17.

Materials, A New Section Instrument for, XVI: 121.

~p of Croup, The—Micrographical Contribution—Ephraim

Insects (2 Plates), I: 68; The Microscopical Examination of Writing for

the Detection of Forgery, Alteration, etc., II: 50; Penetration in Objec-

“a EE ee eee a 20h ros eee oe

a of Lake Erie (1 Plate), III: 51; Wholesale Destruction of Acari by a

___-—s* Fungus, III: 49; Microscopic Forms observed in Water of Lake Erie (1

Plate), IV: 187: A Memoir of William B. Rezner, V: 242; A Combined

Focusing and Safety Stage for Use in Micrometry with High Powers,

__~~~-—sOY WIL: 115; Remarks on Stephanodiscus Niagarw, VII: 139; Note on a New

__—— Rotifer—Gomphogaster Areolatus (1 Plate), IX: 250; Memoir of Allen Y.

- __ Moore, M.D., IX: 327: A New Daphnella, (1 Plate), XII: 172; Additional

_ __— Notes on Gomphogaster, XII: 174; Memoir of Jacob Dolson Cox, XXII:

_—s«:197; Memoir of (Portrait, p. 162), XXIV: 163.

_ Walmsley, W. H. On the Use of Wax Cells in Connection with White Zinc

Cement for Fiuid Mounts, Il: 63; Micro-photography with Dry-Plates and

eg Lamp-Light, and its application to making lantern positives, V: 50, 273;

232 INDEX TO VOLUMES I TO XXV

A Handy Photomicrographic Camera, XII: 69; Some New Points in

Photo-micrography and Photo-micrographic Cameras, XVII: 340; Acety-

lene Gas as the Illuminant in Photo-micrography, XVIII: 136; Photo-

micrography with Opaque Objects (1 Plate), XX: 189.

Ward, Archibald R. The Persistence of Bacteria in the Milk Ducts of the

Cow's Udder (1 Plate), XX: 57.

Ward, Henry B. On the Parasites of the Lake Fish, (1 Plate), XV: 173;

American Work on Cestodes in 1893, XV: 183; The Food Supply of the

Great Lakes; and Some Experiments on Its Amount and Distribution, (2

Plates), XVII: 242; A New Method for the Quantitative Determination of

Plankton Hauls, XVII: 255; Development of Methods in Microscopical

Technique, XIX: 175; Freshwater Investigations during the last Five Years,

XX: 261; A Plea for the Study of Limnobiology, XXI: 201; Notes on the

Parasites of the Lake Fish, (1 Plate), XXII: 175; Data for the Determina-

tion of Human Entozoa, (4 Plates), XXIV: 103; Biological Reconnoissance

of some Elevated Lakes in the Sierras and the Rockies, (12 Plates),

XXV: 127.

Ward, Henry B., Graybill, H. W., and others. A Comparative Study in

Methods of Plankton Measurements, (3 Plates), XXI: 227.

Ward, R. H. Annual Address of President, I: 35; History of the National

Committee on Micrometry, V: 178; The Iris Illuminator, VI: 160; New

Lens Holder, VI: 162; Micrometer Wires, VIII: 89; Remarks on the

Methods of Making Microscopical Societies Successful, VIII: 94; On a

Microscopical Slide—catalogue, IX: 233; Note on Microscopical Exhibi-

tions, IX: 311; Remarks on the Fasoldt Test-plate, IX: 318; An Expedient

for Use in Difficult Resolution, XXI: 111; Library Experiments in Micro-

scopy. Indexing, Cataloguing, Preparing and Arranging Literature and

Slides, XXI: 127; Memoir of Chas. Marvin Vorce, (Portrait, p. 162),

XXIV: 163.

Watch-glass, Syracuse Solid, VI: 178; Improved Syracuse, XVII: 371.

Water Mites, Classification of, XXII: 105; New Genera of, XXI: 177; XXII:

105.

Water, Purification of, XV: 211.

Water Supplies, Chlamydomonas and Effect on, XXI: 97; Surface, Advan-

tages of Field Work on, XXII: 13; Surface, Growths in, XXII: 49; Sur-

face, Collecting Samples for Examination, XXII: 49.

Water Supply, of Cities, Growth of Certain Diatoms in and Relation thereof

to Impurities, IV: 197; Pollution of, XVIII: 182; Public, for Small Towns,

XVIII: 176; Pure, XVIII: 16s.

Water Works, Brooklyn, XXII: 2s.

Wax, Sheet, Punches for, VI: 215.

Wax as a Cell Material—Jas. E. Whitney, VIII: 153.

Wax Cells, How to Make, VI: 214; In Connection with White Zinc Cement

for Fluid Mounts, II: 63; Making and Finishing, XVII: 374.

Weber, H. A. Microscopic Examination of Butter and Its Adulterants, (1

Col. Plate), VIII: 103.

Weisiger, Wm. R., Memoir of, VI: 250.

INDEX TO VOLUMES I TO XXV 233

' ne ng nlp cel

eee SY: 37.

id Dissolved in Natural Waters and the Effect of these Gases

of Microscopic Organisms, (4 Plates), XXIII: 103.

C. The Red Blood Corpuscle in Legal Medicine, (12 Plates),

; Photo-spectrography of Colored Fluids, (1 Plate), XXII: 99;

i 203), XXII: 202.

Punches for Sheet Wax, eae A Cheap and

: 215; Rapid Section Cutting, VII: 122; Wax as a

of Acari by a Fungus—C. M. Vorce, III: 49.

"s Amateur Microscopic Laboratory, XI: 126.

4 Dic Oicsdeas of whe Deaik id x Car Gace

), XVI: 69; Intercellular Spaces in the Embryos of Erech-

ia and Bidens cernua, (1 Plate), XVII: 174

On the North American Species of the Genus Atax

| (5 Plates), XX: 193; New Genera and Species of North

“American Hydrechnide, (4 Plates), XXI: 177; Description of a New Genus

of North American Water Mites, with Observations on the Classification

of the Group, (1 Plate), XXII: 105; The North American Species of

Curvipes, (5 Plates), XXIII: 201; The North American Species of Lim-

ae ss nesiia, (2 Plates), XXIV: 130

_—s- Wollle, Francis. Notes on the Desmidiz of the United States, V: 137; Memoir

i of, (Portrait, p. 244), XV: 245.

_ Woodward, Joseph Janvier, Memoir of, VI: 253.

‘Word Concerning Filar Micrometers, A—Wm. A. Rogers, XIV: 132.

Work of Mt. Prospect Laboratory of the Brooklyn Water Works, The—Geo.