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TRANSACTIONS

OF THE

American Microscopical

Society

VOLUME XXXV

1916

#

ms

4 } : f) At ' |

: Us, ie

@ | My) A r nee a

wi it,

SPENCER-TOLLES MEMORIAL | “et

Bet:

This Society holds a Fund, accumulated in honor of these ‘o ,

pioneer microscope makers and now amounting to nearly $5,000.

The income from this fund is devoted to stimulating research in

any field of microscopy.

TRANSACTIONS

OF THE

American Microscopical

Society

ORGANIZED 1878 INCORPORATED I891

PUBLISHED QUARTERLY

BY THE SOCIETY

EDITED BY THE SECRETARY

VOLUME XXXV

NUMBER ONE

Entered as Second-class Matter December 12, 1910, at the Post-office at Decatur,

Illinois, under act of March 3, 1879.

Decatur, ILL.

Review Printinc & Stationery Co.

1916

,

EVM AT ALD

id

i ; fue :

f oleh OLQS) Gh tiie ee vara Pee cs ia MES © . ee

; Sr ai aly be tay pial bia -

rye ies

if) VAI ATT OA

OFFICERS

MMSE SARE. COVER, © oo 0c, «cis aco Saki v's as oO ORR ORE Madison, Wis.

marst Vece President: T. LL. HANKINSON......0ccvecadadegees Charleston, Ill.

Second Vice President: L. E. GRIFFIN. ..6..cccccsnncccensses Pittsburg, Pa.

Ceasar: sl We GALLOWAY: 5.4.5. wee ee dos aeaoed a escutnoomene Beloit, Wis.

cmeueen:.. Es. Pe. VANCERAUI RSs of uits Wed as cniani ede a eee hues Urbana, IIl.

rrniins- MAGNUS: PYBRAUME DoS acs ctelsaee 0s wa'ew ss aoc k cnt Meadville, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE

Seen POINTE so fate etic at diel} cb cmd ae dwi nd hp aa ahed wie Ann Arbor, Mich.

MIU GMYIE EQS oot a chet ioe ie Panny clara retard sie B eie/k'e oni Walla Walla, Wash.

EX-OFFICIO MEMBERS OF THE EXECUTIVE COMMITTEE

Past Presidents Still Retaining Membership in Society

R. H. Warp, M.D., F.R.M.S., of Troy, N. Y.,

at Indianapolis, Ind., 1878, and at Buffalo, N. Y., 1879

Apert McCatta, Ph.D., of Chicago, IIl.

at Chicago, Ill., 1883

T. J. Burritt, Ph.D., of Urbana, IIl.,

at Chautauqua, N. Y., 1886, and at Buffalo, N. Y., 1904

Gero. E. Fett, M.D., F.R.M.S., of Buffalo, N. Y.,

at Detroit, Mich., 1890

Srmon Henry Gace, B.S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895 and 1906

A. Ciirrorp Mercer, M.D., F.R.M.S., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896

A. M. Breite, M.D., of Columbus, Ohio,

at New York City, 1900

C. H. E1ceEnmann, Ph.D., of Bloomington, Ind.,

at Denver, Colo., 1901

E. A. Brrce, LL.D., of Madison, Wis.

at Winona Lake, Ind., 1903

Henry B. Warp, A.M., Ph.D., of Urbana, Ill,

at Sandusky, Ohio, 1905

Herzert Oszorn, M.S., of Columbus, Ohio,

at Minneapolis, Minn., 1910

A. E. Hertzzer, M.D., of Kansas City, Mo.,

at Washington, D. C., 1911

F. D. Heatp, Ph.D., of Philadelphia, Pa.,

at Cleveland, Ohio, 1912

Cuar_es Brooxover, Pu. D., of Little Rock, Ark.,

at Philadelphia, Pa., 1914

Cuartes A. Kororp, Ph.D., of Berkeley, Calif.,

at Columbus, Ohio, 1915

The Society does not hold itself responsible for the opinions expressed

by members in its published Transactions unless endorsed by special vote.

,

TABLE OF CONTENTS

FOR VOLUME XXXV, Number 1, January, 1916

Masonry Bases for the Installation of Microscopes and Their Acces-

sories, Including the Camera Lucida and the Microscope Camera,

with Plates LIV, by N> A. Cobbei co. ceen seer ae ene saben

Morphology of Adult and Larval Cestodes from Poultry, with Plates

V-VIII, by John E. Gutberlet: . 5... sje maids tae eee e en's suman miele

A Preliminary Study of the Spermatogenesis of Belostoma (Zaitha)

Fluminea, with Plates IX-XI, by A. M. Chickering...............--

Notes and Reviews: A System for Recording Cytological Material,

Slides, and Locations on the Slides, R. T. Hance; A Miniature Dark

Room for Use with the Microscope, R. T. Hance; Notes on a New

Species of Loxodes, E. R. Darling; Entomological Notes, Paul S.

TCO A arssis crea aiv siete rose wie wera fade Big al @inre alere Rlnietale sith le Male einai Neaiaaaatans

Minutes of the Columbus Meeting ...........seeseeeeeceeeeeeeteneees

MRO SECOOEE coede css hic winin,s nin odo np sede eek ce cacind Ste hes either

MM POUAITEE S AEREDOLE. Kociic ac die b'v aes Chietad hpinca.Sd cde deen ge shee Mien eanas

(This Number was issued on March 31, 1916.)

23

TRANSACTIONS

OF

American Microscopical Society

(Published in Quarterly Installments)

Vol. XXXV JANUARY, 1916 Nol

MASONRY BASES FOR THE INSTALLATION OF MICRO-

SCOPES AND THEIR ACCESSORIES, INCLUD-

. ING THE CAMERA LUCIDA AND THE

MICROSCOPE CAMERA

By N. A. Coss

MASONRY AS A BASE

It has long been customary in the best laboratories to mount

instruments of precision upon heavy pillars having foundations

located in wells in the ground and passing upward through the

floors without contact, the object being to prevent the tremors of

the building from being transmitted to the instruments. The earth

receives and nullifies the tremors.

The microscope has not often* received such special attention,

notwithstanding the fact that whenever high powers are used, and

especially when photomicrographs or high power camera lucida

drawings are being prepared, vibration is objectionable. For many

years I have had microscopes mounted on solid bases and strongly

favor this method of support.

THE USE OF GIRDERS

One such installation was carried out in cement and steel as

shown in Fig. 1.** Three girders, two approximately eight inches in

each transverse dimension, and between them a third smaller one,

*The author knows of only about twenty of the massive installations such as

are described in the following pages.

**The illustrations were made under ain meee supervision of the author by

Mr. E. M. Grosse and Mr. W. E. Chambers. h h detail 1

scale, that any good mechanic can build both aay ais pigs & pea ase cad oo

8 N. A. COBB

are imbedded vertically to the depth of several feet in a block of

cement weighing many tons located under the building. The

middle short girder, extending 18 inches above the floor, carries

the microscope and certain accessories connected with illumination.

The two tall, paired girders extend to within eighteen inches of

the ceiling, projecting upward into the room about eleven feet.

The wooden floor was laid tightly about the girders after they had

been set in the cement and everything was then given a few months

in which to settle into permanent position, after which an ordinary

key-hole saw was run through the floor entirely around the contour

of each girder, so that each cleared the flooring and floor-covering

by the thickness of a saw blade. See 3, 43, etc., Fig. 1.

The girders, which clear the wall of the room by an inch or

two, carry the accessory apparatus, which is attached to them in

some instances by means of sliding one-sixteenth-inch sheet-metal

sleeves that may be clamped at any desired height, in other instances

by other means. All parts are dead black. The sleeve of the

small central pillar projects outward at the top, that is, toward the

observer, so as to form a microscope shelf one to two times larger

than the base of the microscope. The sleeve carrying the micro-

scope is clamped to its pillar by set-screws, and can be set high or

low to suit different operators and different classes of work. When

photographing it is better to set the microscope near the floor, so

as to bring the camera (19, Fig. 1) low enough to make it unneces-

sary to use a step-ladder in focusing. By placing the microscope

high and the drawing table low, one can obtain for camera lucida

work a distance of two and one-half feet between the level of the

eye-piece of the microscope and that of the drawing table.

The sleeve carrying the microscope carries also a large vertical

wooden front, two feet wide and as long as the microscope window

is wide. This wooden front or screen slides up and down with

the microscope, and has in it two apertures, one in front of the

microscope mirror, designed to allow light from the sky, or from

an illuminating screen, to strike the mirror and pass thence through

the microscope; and the second to secure a correct illumination of

the drawing board when the camera lucida is in use. See Fig. 1.

This latter aperture is much the larger, is glazed with ground

MASONRY BASES FOR MICROSCOPES 9

glass, and is opened and closed at will by means of a light, sus-

pended, opaque slide worked up and down by foot-power.

The microscope window faces the sun, and is fitted with two

light-proof roller blinds, one just behind the other, so that the sun’s

light may be shut off or allowed full access. The roller blinds

move in lateral grooves ten inches deep, a depth sufficient to pre-

vent the blinds from troubling by bellying on windy days. As a

further provision against wind action, tight wires may be strung

horizontally on the window frame inside the blinds. The blinds

may be of any opaque material, and if long, should be thin. Ordi-

nary opaque window blinds can be sized black so as to become prac-

tically light-proof, and since it is advisable to have two blinds, such

sizing wholly excludes the light. Ordinary spring rollers are used

and are boxed in at the top in a light-tight manner.

CARRIERS FOR THE ACCESSORIES

The right-hand lower sleeve carries a leg-of-mutton shaped

shelf or table for use in making camera lucida drawings. The

sleeve, like all the other supports is balanced with a sash-weight,

so as to move freely up or down through a range of several feet.

The shape of the shelf has been evolved from years of use, and

gives the investigator free play for hands and body. See 33, 34,

Fig. 1.

At the left is a similar sleeve and shelf used for a different

purpose,—although, as it is the mate to the camera lucida table, it

could, in the case of a left-handed operator, be used as the right-

hand table would be used by a right-handed operator. The usual

position for the left-hand shelf is, however, about on a level with

the microscope stage; first, because that is about ordinary table

height and is convenient for supporting the dissecting microscope,

which has a special illumination of its own (See Fig. 1); and sec-

ond, because preparations may then be moved on and off the stage of

the microscope with the least danger and with the greatest facility ;

a third reason is that in this position the left forearm finds it a

most convenient rest in working the fine adjustment screw of the

microscope, as shown in Fig. 3.

10 N. A. COBB

The two long girders also carry two strong vertically adjust-

able cross-pieces for the attachment of accessories above the micro-

scope. Set-screws are provided for clamping the cross-pieces.

Arms extend upward from the cross-pieces to carry anti-friction

pulleys travelling on edges of the pillar. The microscope camera

(See 19, Fig. 1,) hangs above the microscope in readiness for

instant use, and is of vertical pattern, carrying the photographic

plate in a horizontal position. In focusing, the cross-piece carry-

ing the camera is moved upward or downward; a scale on the pillars

gives the various magnifications. The operator loosens two hooks

and the camera front drops instantly into position on the end of

the microscope barrel. The whole is ready for use in a few sec-

onds’ time. If the exposure is long, one leaves the instrument

during the exposure with the greatest confidence that nothing can

disturb it; tremors in the building will not be received either by

the microscope or the photographic plate.

CAMERA LUCIDA

A second attachment of prime importance in producing illus-

trations is the peculiar camera lucida. Fig. 1, 17, 24.

The history of the camera lucida is a very interesting one. It

is impossible to go into details here, but nothing is clearer than that

this instrument is one of great importance to the microscopist, and

its history is in accordance with this fact. The utmost ingenuity

has been exercised to produce an instrument by means of which

sketches of small objects can be made with the aid of the micro-

scope. The necessity for this class of work is very great. The

photographic camera is inadequate for most objects. Only in the

case of smears or exceedingly thin sections, or natural objects of

great thinness, is a photomicrograph satisfactory. In all other

cases, in order fully to elucidate the structure by means of an illus-

tration, it is necessary to represent the appearances at different

depths in the preparation. This can be done only by focusing the

microscope for each particular depth. This fact, thus hastily

explained, is what makes it absolutely necessary to use a camera

lucida for the proper representation of most microscopic objects.

This fundamental necessity is what has given rise to the many

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opaque blind rolling upward carrying with it gq, r, s; u, roller blind

rolling downward carrying with it. g, h, m: wv, set-screws for the shelves'a and b, as well

ten-inch grooves forming light traps for the blinds ¢ and

us; x, chains passing over pulleys to sash weights by

as for the cross-pieces above; w,

which the varidus sliding parts are

counterbalanced; y, z-shaped girders bolted to masonry of the building, :

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MASONRY BASES FOR MICROSCOPES 11

patterns which the camera lucida has taken on during its develop-

ment. The first instrument was an extremely simple one. From

time to time improvements and additions have been made until at

the present time the instruments issued by the best makers are

marvels of ingenuity and workmanship. In fact, in the writer’s

opinion, they are almost too ingenious, for it appears to him that

the various additions instrument-makers have made to the camera

lucida during recent years, while they do accomplish the object

aimed at, do so in an unsatisfactory manner.

To produce a good camera lucida drawing, it is necessary to

have such light passing through the microscope as will enable the

operator to see the object with the greatest possible clearness; and

it is equally necessary so to control the light from the drawing

board as to enable him to see his pencil-point at all times with the

greatest possible clearness. With most objects it is impossible to

secure this adjustment once for all, and for all portions of the

drawing. Different portions of the object transmit or reflect differ-

ent amounts of light, and, as this light varies it is necessary, in order

that the drawing may be made with the greatest ease and precision,

that the light from the drawing board should be modified accord-

ingly. This end has been sought in a variety of ways, and more

than any other one thing the effort to achieve this end has added

to the complexity of the modern camera lucida. When the modern

instrument is in good order, it may, it must be admitted, in a way

accomplish its object; the difficulty is that it is complex and easily

thrown out of adjustment, and some of its parts easily become

soiled and dusty so as to be a hindrance rather than a help. Again,

no very suitable device has yet been furnished by manufacturers

for modifying the light from the drawing paper, except by a

series of steps. It is usual to interpose tinted glasses, until

the right balance of light has been secured, but it often happens

that the most desirable shade cannot be secured, and in any case by

this method there is always being inserted between the object and

the eye, or the pencil and the eye, or between both and the eye,

various pieces of apparatus that must be regarded as necessary

evils, objectionable from a number of points of view.

12 N. A. COBB

A second defect presented by many camera lucidas is the

“double” reflection due to a silvered glass mirror. This defect can

be tolerated for a short time, but after several hours the double

reflection of the pencil point becomes very tiresome to the eye.

Any form of camera lucida hitherto introduced is trying to

the eye-sight. During many years of experience the writer has

endeavored to reduce the risk of injury to eye-sight due to use of

the camera lucida, and the following suggestions, embodied in the

outfits here described, are the result of his experiments. First, he

has substituted for the ordinary mirror a large, and therefore neces-

sarily heavy, 45 degree glass prism mounted on a support separate

from the microscope. (24, Fig. 1 and e Figs. 2,3 and 4). The ad-

vantages of this substitution are: 1. As the prism is mounted sep-

arately, it may be of any desired size, and may be placed at a

considerable distance from the eye-piece of the microscope, thus

increasing the magnification of the drawing; the advisability of

this increased magnification will be dwelt upon later. 2. There

are no double or multiple images and less light is lost by reflec-

tion. The light passes from the drawing-point through the lower,

i. e. horizontal face of the prism in a nearly perpendicular direction

with little loss. It is then “totally” reflected from the oblique face,

again with very little loss. 3. A third advantage of considerable

importance is the stability of the apparatus; it rarely gets out of

register. Forty-five degree prisms are made in about three qual-

ities. The most perfectly corrected ones are very expensive; the

second or even third grade prisms of the best manufacturers are

suitable for camera lucida work.

ILLUMINATION OF THE DRAWING-PAPER

The second modification is that referred to on a previous page

as the suspended slide or blind worked by foot-power. (Fig. 1,

32 and f Figs. 2, 3 and 4). This slide enables the operator

to illuminate the drawing with almost any degree of light at

an instant’s notice without disturbing the adjustment of any

part of the microscope or camera lucida.. This is highly

important in the rapid production of good camera lucida

sketches. Especially with high powers, the light coming through

MASONRY BASES FOR MICROSCOPES 13

the microscope is often so faint that it is only by almost

completely shutting off the light from the drawing, that the investi-

gator can see at the same time both his pencil and the details of

the structures to be sketched. With the foot-power arrangement

the operator modifies the light in a second without disturbing the

position of his body or his drawing-point, and instantly brings about

that adjustment which is most favorable for any particular part of

the sketch. Briefly, we may say that the operator’s left arm rests

on the left-hand “leg-of-mutton” shaped table on a level with the fine

adjustment of the microscope, with his left hand in position to work

the fine adjustment screw with the greatest ease and accuracy. His

right hand, carrying the drawing-point, rests on the drawing board

and is engaged in producing the sketch. As the light required

for the different portions of the sketch varies he can effect the

necessary change in illumination of the drawing paper by a slight

movement of his right foot, which disturbs neither his hands nor

the equilibrium of the instruments.

METHOD OF TRACING CAMERA-LUCIDA DRAWINGS

As will be at once conceded by any one who makes a trial,

black paper is best adapted for camera lucida drawing; a white

drawing point should be used. This is an improvement over a

pencil used on white paper. The best combination is a thin black

tissue-paper, blued on the under side by rubbing on dry prussian

blue powder. A piece of drawing paper or enameled board of

suitable size for the drawing is pinned to the drawing board,—i. e.,

the right-hand leg-of-mutton shaped table,—and is then covered

with the black tissue-paper, blue side down, pinned at its back edge

only. The sketch, a blue tracing, is now made with a fine white

ivory or bone point. This blue sketch is put aside for further

reference, or for the production of a finished drawing later on, or

it may be inked in at once. The object aimed at is a satisfactory

representation of the object to be illustrated, of sufficient size to

admit of liberal reduction when the ink drawing is photographed

_on metal preparatory to etching. If it is desired to publish an

illustration having a magnification of say 250 diameters, it is ad-

visable to produce a blue sketch of at least 1,000 to 2,000 diameters.

,

14 N. A. COBB

Highly magnified sketches are easily obtained with the apparatus

just described, for by placing the prism reflector at a considerable

horizontal distance from the eye-piece of the microscope, say one

foot, and lowering the right-hand leg-of-mutton shaped table, mag-

nifications of 5,000 diameters and upward are easily secured. Not

infrequently the production of a large coarse drawing is an easier

matter than the production of the same drawing on a smaller scale.

The conversion of the blue sketch into a pen and ink drawing pre-

sents no special peculiarities, but perhaps it ought to be mentioned

that the object of using blue is to avoid trouble arising from altera-

tions that may become necessary in finishing the drawing. Any light

blue lines which are left on the drawing paper need not be removed,

as they do not affect the photographic film sufficiently to cause any

inconvenience in the production of an etched block. The black

tissue paper mentioned is produced by inking ordinary tissue. The

ordinary blue carbon paper gives too dark a blue to meet the

requirements. A good quality of blue tracing paper may be made

from black typewriter carbon-paper that has been exhausted by

the typewriter,—the blue powder being rubbed onto the clean side

of the carbon paper.

DARKENING THE ROOM CONTAINING THE INSTALLATION

In addition to blackening all accessories, arrangements are

made to darken the room itself, in fact, to make it convertible into a

photographic dark-room at will. All the window-blind connections

are light-tight. The oblong aperture, about five inches by eight

inches, through which the microscope mirror receives its light is

screened by means of several thicknesses of flexible black cloth

made into the form of a sleeve. This cloth sleeve, attached to the

perimeter of the beveled aperture, is slit above and made to surround

the microscope just beneath the stage, and the margins overlap and

button to one of the screws at the back of the microscope; the low-

er part of the microscope is thus located within the sleeve. No

light reaches the observer’s eye except that which comes through

the instrument.

MASONRY BASES FOR MICROSCOPES 15

If, now, the slide in front of the large glazed aperture be closed

and all direct light shut out, the operator sits in darkness. Any

one who has had experience with a photographic dark-room must

have observed how after a period of from five to ten minutes there-

in the eye becomes accustomed to the darkness of the room and is

able to distinguish objects much more readily than at first. This

is a principle which can be utilized to advantage in connection with

high-power microscope work. In fact, it appears to be the relation

between the external and the internal illumination which leads so

many operators to use artificial light, and even in some cases to

prefer working in the evening. If the surrounding light is dim

and the eye is allowed to adjust itself to this dimness, then on look-

ing through the properly adjusted microscope, certain details

may be seen more clearly than in any other way. It is sometimes

painful to witness the unconscious efforts of microscopists to bring

about this condition as fully as possible by means of awkward atti-

tudes and facial expression. It is not at all uncommon to see the

microscope placed in a glare with strong light beating on the top of

the preparation being examined and thence reflected confusingly

up through the microscope, and to see the operator sitting in a

cramped position, bending his head over the top of the instrument

so as to shade his eye-piece as much as possible, and thus prevent

eye-piece reflections. All this painful effort is simply an attempt

to give the eye the benefit of a weak extraneous light and to pre-

vent confusing reflections from the top of the mount and the eye-

piece. With the apparatus here described’ these difficulties are

minimized. The room is darkened. All light which could

reach the operator’s eye is excluded, except that which comes

through the microscope. There is no light falling upon the top of

the object, to cause confusing reflections inside the microscope, nor

can rays of light be thrown into the eye from the top of the eye-

piece, or from high lights on the stand. The image to be examined

is as clear as it can be made and the eye is given every facility to

see it, and is distracted by no others.

The advantages of this system of using a microscope are not

confined to high-powers. It is well known that the central portions

of microscope lenses act more perfectly than the peripheral portions.

,

16 N. A. COBB

By shutting out these latter, better optical results are secured, but

the illumination is considerably diminished. The low degree of

illumination is less objectionable when the observer is in darkness

or semi-darkness. I believe this is due to some extent to relaxa-

tion of the iris muscles.

It might at first be thought that this would result in a less per-

fect image on the retina of the eye, and no doubt this is true if we

consider the entire image on the retina. The fact is, however, that

the observer concentrates his attention upon a small portion of the

retina image and this portion may be focused as accurately as his

eye admits. In respect to perfection of image, a comparison of the

human eye to an ordinary camera may be very misleading.

CAMERA-LUCIDA DRAWINGS OF DIFFICULT OPAQUE OBJECTS

Camera lucida drawings of opaque objects present numerous

difficulties, prominent among which is the small amount of light

coming through the microscope. By illuminating the object with a

strong light, sunlight if necessary, and reducing to a minimum the

amount of light coming from the drawing paper, it is not at all

difficult with this apparatus to produce satisfactory drawings of

these difficult objects.

Needless to say the apparatus is a daylight apparatus. It

hardly seems necessary to argue that as daylight is the light that has

developed the human eye it is probably the light to which it is best

adapted. This seems a sufficient argument for the use of daylight

and a sufficient explanation of its superiority to every other light

for the average run of microscopic work. Using the installations

here described, monochromatic light of superlative quality is easily

obtained by interposing colored glasses or liquids. However, when

all this is said, it is not possible always to secure and control day-

light so as to get the best results. The following contrivances are

such as experience has shown to be very useful for this purpose,

especially in sunny climates.

SOURCE OF LIGHT FOR THE MICROSCOPE

Outside of the microscope window a universally adjustable

three-by-five-foot white screen is placed in a sunny position, prefer-

ably about ten feet away. The surface of this screen should be

a ee,

MASONRY BASES FOR MICROSCOPES 17

smooth but not shiny and may be of any fine-grained white material.

It can be made of wood, painted white, or lined with plaster of

Paris; or, what is better, be a plain wooden screen covered with

sheet metal and over all several thicknesses of bleached cotton cloth.

Whitewash makes a cheap and very excellent white surface for

this purpose, and may be applied over cloth. If a small mirror be

attached to one corner of the screen, it will indicate the position of

the screen that will reflect to the microscope a maximum of white

light. Place the screen so that the flash of sunlight from the mirror

strikes in the vicinity of the microscope; then the whole screen will

be in corresponding position and reflect a maximum of. light to the

microscope. It is better if this screen can be adjusted from the

interior of the microscope room, but this is not essential. After

the screen is set the light from it remains for an hour or more

practically constant, so that while an adjustment by cords or other

mechanism from the interior is a convenience, it is not a necessity.

If an adjustable screen is not available it may be possible to arrange

two fixed screens, one screen for morning and the other for

afternoon.

Blue sky is not a satisfactory source of light. A white cloud

gives a very good light, but clouds are so changeable that it is not

wise to rely upon them. It is therefore much preferable to con-

struct, as described, an adjustable white screen that will be avail-

able whenever the sun shines. When the sun does not shine the

sky may serve, or if the day is too dull, one resorts to artificial light.

MICROSCOPE INSTALLATION BOLTED TO THE MASONRY OF

THE BUILDING

The installation just described can be bolted to the masonry of

the building by means of small vertical I-shaped or Z-shaped girders

as shown in Fig. 2. The installation is in most respects similar to

that just described, except that the microscope is carried on a heavy

cast-iron cross-piece, m, sliding up and down on a pair of L-shaped

or Z-shaped girders, and carrying with it an opaque roller blind, u,

which passes around a roller at the bottom of the window near

the floor.

18 N. A. COBB

In Fig. 2, a number of details are more clearly shown than in

Fig. 1, for instance, the details of the headrest, j, which consists

of two oblique cork-covered pads, one circular, the other square,

each carried on a horizontal screw so that they can be rotated

and at the same time moved inward or outward. These pads

screw into a cross-piece, which in turn is fastened securely to a

vertical rod which slides up and down and rotates, and is clamped

by the set-screw shown near k. The great adjustability of these

pads makes it easy to fit them to the head of any operator. They

serve to keep the observer’s eye in register, as well as to decrease

fatigue, and actually improve his observing power.

Owing to the action of the heart and lungs, and to the unsteady

action of the muscles of the neck, the head, when unsupported,

‘dorso-ventral XFS

é 47a es i :

: a :

: a ;

: . , i f

Bek

: |

be Ab wd eins

f i 1 6

:NW ¥ \w Bes NM Naik

Jateral

: {

t {

| | Oe

{

6

; i : i

eee a

vertical 1 =| Vin ty [Wk |

i a i j !

; t i

i ir | lo

0 jo: 20°. 9a! 40. ee

Fic. 5. Three successive graphs showing the nature and extent of the motions of

the head of an observer while looking through a microscope. These graphs were obtains

by recording the trace of a beam of light yeas a small mirror actuated by the head o

the observer at the microscope,

MASONRY BASES FOR MICROSCOPES 19

is in constant motion, and the image of any stationary object formed

meanwhile on the retina of the eye is moving in a corresponding ©

way. The movements of the microscopist’s head are shown in

the accompanying three graphs (Fig. 5). Both the nature and

extent of the rotations about three coordinate axes, at right angles

to each other, are shown at a magnification of 35 diameters.

These graphs were obtained by recording the trace of a beam of

light reflected from a small mirror actuated by the head of the

observer at the microscope. The smallest motions indicated in the

graphs, a, a, a, are due to the action of the heart; each tiny irreg-

ularity represents a heart-beat. The larger irregularities, such as

those shown at b, b, b, are due to lung action; the head rises and

falls with each breath. Moreover, these two irregularities, those

due to the heart’s action and those due to the action of the lungs,

are distributed on a great curve, which I suppose to be a curve of

fatigue connected with the action of the muscles of the neck. These

graphs show how complicated are the movements of the image on

the retina. Keenness of vision is a function, among other things,

of the steadiness of the retina. This is a matter of personal ex-

perience, but arguments in favor of a steady retina may be sug-

gested somewhat as follows: It is a matter of common observation

that all organisms possessing well-developed eyes, hold the head

as steady as possible when looking intently. If while reading from

a printed page one wags the head perceptibly, even at so slow

a rate as that of the heart’s beat, vision is very considerably im-

paired; the less of this motion, the keener the vision. What is

the limit of this improvement in vision due to increased steadiness

of the retina? Theoretically it would seem to be reached when

the retina is absolutely steady. When we consider the minuteness

of the elements in the retina having to do with vision,—the rods

and cones and other elements—it seems a very reasonable sup-

position that vision can be increased in keenness beyond the degree

attained by holding the head as steadily as possible by means of

the cervical muscles. Whether these arguments are valid or not,

the writer is convinced, from years of experience with mechanical

headrests, that their use adds to the acuteness of vision. More-

over, they diminish fatigue, making it possible for the observer

20 N. A. COBB

to use the microscope hour after hour continuously with a smaller

expenditure of energy.

The attachment of the large prism is also more clearly shown

in Fig. 2. It is mounted on a triangular sheet-metal frame, which

revolves on a vertical axis, and is clamped in any position by means

of the lever shown in the midst of the triangle. |

Fig. 3 is an outside view of the installation shown in Fig. 2,

and is correspondingly lettered. Note the headrest in use, and

also the spectacle lens between the operators’ eye and the prism, e.

This spectacle lens is one adapted to the operator’s eye, and in case

he is accustomed to wear ordinary spectacles for reading or draw-

ing, he is able to dispense with them, which is an advantage, as they

would be a hindrance in camera lucida work. The substituted

spectacle lens should be made by the optician who makes the oper-

ator’s spectacles, and according to much the same formula; this

lens enables the operator to see his penctl point and drawing clearly.

In this illustration is also shown on a shelf in front, a

small heliostat, actuated by the small alarm clock, the top of which

is to be seen in the figure. The lower reflector of the heliostat is

a mirror, the upper a piece of finely matt white card-board. This

heliostat may be used instead of the large reflector previously

described, and gives a very good light.

INSTALLATION CARRIED OUT IN STEEL TUBING

The installation shown in Figs. 1, 2, and 3 may be carried out

in steel tubing as shown in Fig. 4. This form of installation has

not yet been thoroughly tried out, but appears to offer a number of

advantages over the other forms at an expense but little, if any,

greater. The peculiarities of the construction are well set forth in

Fig. 4, and as the lettering is the same as in the preceding figures,

little need be added. It will be noted that the sash weights are for

the most part suspended inside the tubes, and that the various acces-

sories slide up and down on the tubes through the mediation of

cast iron rings, malleable castings, turned to fit the tubing somewhat

loosely. The microscope is supported on a vertical tube descending

MASONRY BASES FOR MICROSCOPES 21

into another tube of slightly larger size embedded in the cement

below, and is counterpoised by a weight which slides in a third

smaller tube, also embedded in the cement below. The details are

shown in section in the illustration. Collars threaded into the out-

side tube are turned to fit the tube carrying the microscope. The

cross-piece, 1, is suspended on metal straps passing into the spring-

pulleys, xx. In all other respects the installation is almost identical

with that shown in previous illustrations.

Ordinary rough tubing may be used if its outer surface is

smoothed by filing. With such a rough finish, however, the appar-

atus is liable to be noisy during the adjustment of the various slides.

This noise can be eliminated by turning the tubes in a lathe having

a long bed, and carefully fitting the cast iron rings to the tubes.

With good fitting the apparatus is then practically noiseless. This

turning and fitting, however, adds materially to the expense. This

installation is neat in appearance, and easy to work. The tubing

used is from 3% inches to 6 inches internal diameter.

This installation differs from those shown in Figs. 2 and 3 in

respect to the screen in front of the microscope through which light

is admitted to the mirror of the microscope and to the drawing.

In the present installation this screen is attached to the tube that

carries the microscope, and therefore slides up and down with this

tube and with the microscope substantially as shown in Fig. 1. In

the tubular installation, therefore, this screen is of very light con-

struction,—made of wood, and very thin,—and its ends, as in Fig.

1, extend deeply into the 10-inch groove at either side of the

window.

In Fig. 4 the cloth sleeve that surrounds the microscope has

been removed, so as to show the size and nature of the aperture

through which-the light is admitted to the mirror of the microscope.

It will be seen that in this aperture light-filters in the form of

glass tanks or colored glasses can be installed ad libitum. This

method of using tanks and glass filters is a very convenient one.

Those of large size can be used.

22 N. A. COBB

The shelf at the top of the installation, carrying the spring-

pulleys, x, x, and clamped in position by the higher set-screws, v, v,

and supporting the pulley, 0, has for its main object to keep the

four cylindrical pillars in register,—that is, parallel to one another,—

and to prevent vibration.

MORPHOLOGY OF ADULT AND LARVAL CESTODES

FROM POULTRY*

Joun E. GuTBERLET

During the course of experimental studies on the life history

of certain chicken cestodes described in the succeeding section of

this work (Gutberlet, 1916) it was necessary to determine exactly

the morphological features’ of the species, which to be sure, had

been studied by others but were only partially and imperfectly

known. In the former paper I recorded experiments which demon-

strated the intermediate stage of Choanotenia infundibuliformis to

be in the common housefly, Musca domestica, and discussed the

symptoms of infection and methods of control for tapeworm dis-

eases in chickens.

In this paper are taken up the structure of the adult and cysti-

cercus of Choanotenia infundibuliformis (Goeze), and also the

adult form of four other species occuring in chickens of this

country.

As described more fully in the preceding paper the worms

were removed from the intestine under water. The use of normal

salt solution was avoided since it was found to be injurious. The

cestodes were killed in a corrosive-acetic solution and preserved in

70% alcohol and glycerine. Best results were secured by staining

in Delafield’s or Ehrlich’s acid hematoxylin and destaining in acid

alcohol.

The five species discussed here were collected at two widely

separated points, a farm at Hardy, Nebraska, and the poultry farm

at the University of Illinois. These morphological studies were

carried on at the Zoological Laboratory of the University of IIli-

nois. This work was taken up at the suggestion of Dr. Henry B.

Ward, to whom I am greatly indebted.

*Contributions from the ag gir Laboratory of the University of Illinois under

the Direction of Henry B. Ward, No. 57.

24 JOHN E. GUTBERLET

STRUCTURE OF ADULT AND LarvA (CyYSTICERCUS)

A. ADULT

Choanoteinia infundibuliformis (Goeze 1782) Railliet 1896

1. Diagnosis: Length 50 to 200 mm. Scolex (Fig. 2) small,

rounded, or conoidal, about 0.4 mm. wide. Rostellum (Fig. 2, 3, r)

60 to 70p in diameter, armed with a single row of 16 to 20 hooks

(Fig. 8) 25 to 30% long, with long dorsal root and short ventral

root. Suckers prominent, elongated antero-posteriorly, length 180

to 210u; breadth 135 to 175u between the extreme outer edges.

Neck short and unsegmented, somewhat narrower than broad. In

specimens well extended neck much narrower than head. Anterior

proglottids very short and as they become older funnel-shaped,

much narrower at anterior than at posterior margins; posterior

segments 1.5 to 2.5 mm. broad and 1.5 to 3 mm. long according to

amount of contraction, with convex lateral borders, nearly as wide

at anterior as at posterior margin. Genital pores irregularly alter-

nating, situated one in each segment in the anterior third of the

lateral margin, usually under cover of the backward projecting bor-

der of the preceding segment. Vas deferens (Fig. 14, vd) and

vagina pass between excretory canals and dorsal to nerve trunk.

Male Reproductive Organs: Testicles (Fig. 14, t) 25 to 40

or more, 60 in some cases, in posterior half of proglottid, posterior

and lateral to large yolk gland, within limits of excretory canals.

Vas deferens passes forward and in anterior third of proglottid

forms a mass of coils between ovary and excretory vessels from

which it extends outward as a convoluted tube to base of cirrus

pouch. Cirrus pouch (Fig. 14, 15, cp) ovoid in shape, 75 to 95

in long diameter. Portion of vas deferens in cirrus pouch is much

coiled. Cirrus 50 to 65, long, armed with spines; outer surface of

cirrus pouch forms base of deep genital cloaca.

Female Reproductive Organs: Vaginal opening in genital

cloaca posterior to cirrus. Vagina posterior to cirrus pouch, after

crossing ventral excretory canal dilated to form ovoid seminal

receptacle, posterior and ventral to vas deferens, extending to well

developed shell gland, 40 to 50 in diameter located in front of

middle of proglottid. Transversely elongated ovary (Fig. 14, 0)

MORPHOLOGY OF CESTODES FROM POULTRY 25

occupies anterior portion of middle field of proglottid in front of

shell gland. Large yolk gland posterior to ovary and shell gland,

irregular in shape, elongated transversely, with convex ventral sur-

face and concave dorsal surface. Uterus (Fig. 16, u) developed

as tube between anterior and ventral lobes of ovary. Gravid uterus

fills up most of proglottid, extending beyond excretory canals on

each side. Eggs oval (Fig. 7), with very thin membrane next em-

bryo, followed by thick, smooth membrane 40 by 32 to 45 by 36

in diameter, and one or two outer membranes, very thin and wrink-

led in preserved material. Diameter of outer membrane 65 by 40p

to 60 by 45; at each pole of outer membrane a delicate appendage.

Embryonal hooks 18y long. Embryo 32 by 22, in diameter.

2. Morphology: The scolex of the living worm shows up

very prominently and can be used as a distinguishing feature.

When first removed from the intestinal wall the suckers appear

distinct and the neck is much narrower than the scolex. Soon

after the removal it often contracts and takes on the appearance of

a flattened bulb which includes the neck and anterior segments

(Fig. 1). This feature is characteristic of this species and is a

factor which alone assists very materially in distinguishing it from

others that occur in chickens.

The rostrum or crown of the scolex is somewhat pointed when

the rostellum is enclosed within its sheath (Fig. 2). The rostellum

is an ovoid structure with a bulbous expansion at its anterior end.

It has a length of 140» and a breadth of 60 to 65» at its anterior

end. A crown of 18 hooks is arranged in a-single row around the

bulbular anterior end. The structure of the wall is of a fibrous

nature and presents a transversely striated appearance due to con-

traction. In the interior of the rostellum the structure is a con-

nective tissue mass with few cells, some of which possess long

processes. The hooks (Fig. 8) are 30u in length with a long dorsal

root and a short ventral root.

The rostellar sheath or sac (Fig. 3, rs) into which the rostel-

lum is withdrawn is oval in shape and 230 to 240 in length by 80

to 90u in width at its broadest point. Histologically, the structure

is that of a fibrous connective tissue type with spherical and spindle-

shaped cells. The cells coming in contact with the rostellum, as

,

26 JOHN E. GUTBERLET

well as those on the outer edge of the sac, bear long processes. The

outer layer of the rostellar sac is composed of longitudinal and

oblique fibers of a muscular nature which probably have for their

function the movement of the rostellum.

The four excretory canals, that have extended forward through

the entire length of the body, unite in the scolex to form a ring

(Fig. 3, ex), which lies in the tissue of the rostellar sac around the

body of the rostellum.

The suckers are prominent. They are oval in shape and in

preserved specimens measure 180 to 210» in length and from 135

to 175 in extreme breadth. In the center of each sucker there is

a depression or an acetabulum, 30 to 40u in diameter. The entire

inner surface of the suckers possesses minute hooklets or spines

(Fig. 4) 1.5 to 2u long. These hooklets not only line the suckers

but also extend over the entire surface of the scolex (Figs. 3, 5)

and down onto the neck region; they disappear before reaching

the first segment. They appear more distinctly on scolices that are

somewhat contracted than on those that are well extended. These

hooklets can be seen only in sections as they are too small to be

distinguished readily in whole mounts.

Musculature: The longitudinal muscle fibers are arranged in

bundles which are scattered, forming a loose irregular layer. The

bundles are numerous and nearly of a uniform size. There are no

transverse muscle fibers present except a few minute oblique fibers

which connect some of the longitudinal fibers near the ends of the

proglottids. Some dorso-ventral fibers are present, but they are

not abundant.

Nervous System: The longitudinal nerve fibers are arranged

in fiber tracts which approach the structure of a nerve cord. The

individual fibers do not form a compact mass, but are more or less

free in the tract. Nerve cells have no definite arrangement, but

are situated irregularly along the fiber tract (Fig. 6). The nerve

cells are somewhat spindle-shaped and quite large, being from 20

to 25y long by 6 to 8» wide with large nuclei. Transverse nerves

are composed of individual cells with long processes extending

transversely from the lateral fiber tracts. The transverse fibers are

much scattered and have no definite arrangement except that they

MORPHOLOGY OF CESTODES FROM POULTRY 27

are more numerous near the ends of the proglottids. Peripheral

nerve cells are widely and irregularly distributed. They are more

numerous at the anterior end of the proglottids, especially on the

portion that is covered by the backward extension of the preceding

segment.

Excretory System: The excretory system is fairly well devel-

oped in this form. The ventral canal (Fig. 14, v ex) is the larger,

and has a diameter of 28 to 30u. A transverse canal unites the

two longitudinal canals in each segment. The dorsal canals (Fig.

14, d ex) are much smaller, having a diameter of 6 to 8u and are

not united by transverse connections. The four longitudinal canals

extend anteriorly to the scolex where they unite to form a ring

which lies in the rostellar sheath around the body of the rostellum.

The vas deferens and vagina pass between the dorsal and ventral

excretory canals.

Male Reproductive Organs: The testes vary in number, us-

ually from 25 to 40, but in a few cases the number is much greater,

being as high as 55 or 60. The testes are quite large, being from

40 to 55 in diameter, and are located in the posterior half of the

proglottid (Fig. 14, t), posterior and lateral to the yolk gland. The

testes are not arranged in layers, but are grouped in a more or less

compact mass almost entirely within the limits of the excretory

canals. The vas deferens (Fig. 14, vd) in the anterior third of

the proglottid forms a coiled mass at the side of the ovary, from

whence it passes laterad to the cirrus pouch as a convoluted tube.

The portion of the vas deferens inside the cirrus pouch is coiled,

varying in extent in different specimens (Figs. 14, 15). The vas

deferens passes into the cirrus. There is no seminal vesicle formed

by the vas deferens in the cirrus pouch nor are there any accumu-

lations of sperm cells. The cirrus pouch (Fig. 15) is ovoid in

shape and is from 75 to 90u in diameter. The wall is made up of

layers of fibers which are both circular and oblique, forming a

basket-like network which incloses the cirrus and a portion of the

vas deferens. The outer wall of the cirrus pouch forms the inner

wall of the deep genital cloaca. The cirrus is a compact structure

from 50 to 65 long and lined with spines. It is a slightly curved

structure passing from the cirrus pouch and curving posteriorly

,

28 JOHN E. GUTBERLET

toward the vagina which is directly posterior to it. The cirrus was

not observed extending from the genital cloaca, but was noted in

some specimens curving toward the vagina, though not passing into

it. A few sperm cells were present in the vas deferens, also in the

vagina and the seminal receptacle.

Female Reproductive Organs: The large ovary (Fig. 14, 0)

lies in the anterior third of the proglottid and extends transversely

across the segment. It has a length of 300u and a breadth of about

75 or 80p at its broadest point. It is irregular in shape, being com-

posed of a number of lobes. The end which is nearest the genital

pore is smaller than the other, allowing room for the mass of coils

of the vas deferens, the vagina, and the seminal receptacle. The

ovary is concave on the dorsal surface and convex on the ventral.

On the dorsal surface of the end nearest the genital pore is located

the seminal receptacle and the vagina. The ova are large and very

distinctly shown in the ovary (Fig. 16). Posterior to the ovary is

the large yolk gland (Fig. 14, 16, y) which lies about the middle of

the proglottid. It is irregularly elongate in shape and extends

transversely across the segment, having a length of from 120 to

130p and a breadth of from 35 to 50u. Immediately in front of and

dorsal to the yolk gland and posterior to the ovary is the shell gland

(Fig. 14, sg) which is slightly ovoid in shape, 40 to 50 in diameter.

A small duct, the vitelline duct (Fig. 16, v), passes from the yolk

gland through the shell gland from which it receives a duct. The

combined ducts after passing through the shell gland unite with the

oviduct (Fig. 16, ov) which appears as a curved tube leading from

the ovary. These united tubes or ducts pass anteriad and slightly

ventrad into the uterus which develops as a blind tube in the region

of the ventral lobes of the ovary. This blind tube (Fig. 16, )

grows in size and extends transversely across the segment. As it

becomes larger the tube forms pockets which extend anteriorly and

posteriorly and also dorsally, until it takes up the entire mass of

the proglottid between the excretory canals. In gravid segments

it even extends beyond the excretory canals. A small tube or duct,

which is really the end of the vagina, connects the seminal recep-

tacle with the yolk-shell gland duct and oviduct. This tube serves

to carry the sperm to the eggs in the oviduct for fertilization. The

MORPHOLOGY OF CESTODES FROM POULTRY 29

seminal receptacle (Fig. 16, sr) is a dilation of the vagina into an

oval shaped structure which is about 50” long and from 25 to 30p

in breadth at the widest part. From the seminal receptacle the

vagina passes laterad, lying posterior to the cirrus pouch, and unites

with the genital cloaca. The genital cloaca has its pore on the

lateral margin near the anterior end of the proglottid. The pore is

usually covered by the backward projection of the segment anterior

to it. The vas deferens and vagina pass between the dorsal and

ventral excretory canals and dorsal to the nerve tract. The vas

deferens is dorsal and anterior to the vagina.

In the mature segments the uterus becomes filled with ova and

it increases in size until it occupies the entire area between the

excretory canals, even extending beyond the canals in the gravid

proglottids. The uterus finally breaks up into compartments, each

containing a single embryo. The embryos (Fig. 7) are about 32

by 22» in diameter with onchospheric hooks 18» long. Usually

three membranes, but often four, enclose the embryo. The inner

membrane is thin and closely surrounds the embryo; the next is

heavy, being from 1.5 to 2p thick, composed of fibrous layers with

a few cells present. This layer is variable in thickness, depending

considerably upon the amount of contraction of the segment, as it

ranges in size from 40 to 32 to 50 by 36p, or it may be even

slightly larger. Usually one (Fig. 7) and sometimes two thin mem-

branes are found on the outside of the thick layer. These are

often wrinkled and bear at each end an appendage formed from

the outer membrane by which it is attached to the wall of the cap-

sule or compartment of the uterus.

In this species the oldest proglottids drop off from the worm

before they are fully mature. The embryos from the oldest seg-

ments on the worm do not show the characteristics of entirely ma-

ture ones, and there are distinct differences between them and those

that have been separated from the worm for some time. Single

proglottids that have separated from the worm are quite active and

remain in the intestine for some time before passing out with the

feces. Proof of this is furnished by the fact that a large number

of the free proglottids are found in the intestine at any time. Even

tho only a few worms are present in the intestine of a bird there is

30 JOHN E. GUTBERLET

usually a large number of free proglottids. If they did not remain

in the intestine for a considerable length of time there would not

be nearly as: many. Further proof is furnished by the fact that the

free proglottids have embryos which are mature, showing the oncho-

spheric characteristics, while the oldest segments that are still at-

tached to the worm have embryos that are not entirely mature.

This same condition has been observed in Davainea proglottina as

Blanchard (1891:435) states that the oldest proglottids separate

from the others and remain in the intestine to become mature be-

fore passing out. The proglottids do not always separate from the

worm singly, but may drop off in groups of three or four.

The fact that the proglottids separate from the worm before

they are entirely mature is one of great importance in taking up

experimental work for infection of intermediate hosts. If the em-

bryos are fed to insects or other invertebrates before they are ma-

ture they will be digested, and thus infection cannot be produced.

B. CYSTICERCUS

The cysticercus of Choanotenia infundibuliformis was found

in the abdominal region of the body cavity in the common house

fly, Musca domestica. The flies had been fed on embryos from

ripe proglottids of this species of worm, and at the end of twelve

days were killed. The cysticerci appear to be nearly ripe or ready

for transmission into the adult host. The time for the develop-

ment of the cysticercoid varies with different species and under

different conditions. Grassi and Rovelli (1892:85) found that

Davainea proglottina developed from the onchosphere into a ripe

cysticercus in less than twenty days. Schmidt (1894:9) found that

the development of the cysticercoid of Drepanidotenia anatina

(Krabbe) varied with the time of the year and the influence of the

temperature. In the summer the embryo developed in an ostracod,

Cypris ovata, into ripe cysticercoids in two weeks.

The cyst proper (Figs. 11, 12, c) containing the scolex is oval

in shape, 220u long and 120p in diameter.

The bladder (Fig. 12, b) or tail, which is also oval in shape,

is located against one side of the cyst and is somewhat flattened on

that side. It is 220 to 230n long and from 116 to 120, in breadth.

MORPHOLOGY OF CESTODES FROM POULTRY 31

The scolex is 80 in breadth and 120, in length; neck is 40y in

diameter and 30 to 35u long; suckers are 55 to 60 in diameter.

The rostellum is 60 long and 20y in breadth, armed with a crown

of 18 hooks arranged in a single row. These hooks (Fig. 9) are

30» long with a long dorsal root and a short ventral root. The

suckers are lined with numerous minute hooklets or spines 1.5 to 2u

long which extend over the edges of the suckers and also over the

greater part of the surface of the scolex, including a part of the

neck region. Schmidt (1894: 16) described cuticular hooklets on

the suckers of Drepanidotenia anatina.

The size of the scolex may be somewhat variable as shown by

those in the cysticercoids of Drepanidotenia anatina by Schmidt

(1894: 10). In that species the intermediate host could be one of

two or more species of crustaceans and the size of the cysticercoid

varied with the size of the host in which it was parasitic.

The head of the rostellum is conical in shape, bearing a bluntly

pointed apex anterior to the end of the dorsal roots of the hooks

(Fig. 10, r). This part of the rostellum is composed of minute

muscle fibers which are both circular and oblique. The rostellum is

slightly broader below the circle of hooks as it is an oval shaped

body.

The rostellar sac (Fig. 10, rs) is a deeply stained structure 10

to 12» thick. It extends from 10» below the hindermost part of

the rostellum to the anterior extremity of the scolex, forming an

oval shaped sac or sheath. It is composed of parenchymatous

tissue with large heavily stained oval or spindle shaped cells which

bear processes. The outer part of the sac is composed of a thin

layer of fine fibers which help to give it a definite shape. At the

lower edges of the sac the fibers are connected or associated to

some extent with similar fibers that form the inner layer of the

suckers. The anterior region of the rostellar sac, which forms

the sheath for the free head portions of the rostellum, is constructed

of an inner layer of fine fibers and an outer layer of large spindle-

shaped cells, the most of which bear fibrous processes at one or

both ends.

The suckers are composed of large spindle-shaped cells which

are arranged perpendicular to the edge. These are heavily stained

,

32 JOHN E. GUTBERLET

and form a compact layer. The inner boundary of the suckers

is composed of a layer of fibers which are both circular and oblique.

Some of these at the upper edges are associated with similar fibers

in connection with the rostellar sac.

The cyst is composed of two cell layers with an irregular

cavity between them. The cells are large and irregular in shape

with no special arrangement in the layer. Large intercellular

spaces lie between the cells, thus forming a loose network structure,

except at the base of the neck. At this point where the neck is

attached to the inner layer of the cyst the cells are smaller and

are in a compact mass. There is no definite boundary to the outer

part of the inner layer as well as to the inner part of the outer

layer of the cyst. Few cells with long connective processes extend

across the cavity from one layer to the other. This then forms

an irregular cavity (Fig. 11 ca) 2 to 20u in width between the two

layers of the cyst. This is the primitive cavity of Grassi and

Rovelli (1889: 373). The two layers of the cyst are formed

apparently by a fold which extends upward and inward from the

base of the neck, forming the gastrula cavity of Grassi and Rovelli

(1889: 402, g) and enclosing the scolex. This cavity varies in

width from 3 to 10 or 15z.

The bladder, an oval shaped structure, is located at one side

of the cyst and is attached to it at the posterior end by a narrow

connection (Fig. 12, cn). The posterior end of the cyst or the

region caudad of the base of the neck is somewhat drawn out

(Fig. 12). From this point is given off the attachment to the

bladder or tail portion of the cysticercoid. The fact that this

bladder is really a tail, even though it possesses a cavity, is shown

by the presence of the onchospheric hooks, which are located at

the end of the bladder opposite to that of the attachment of the

cyst (Fig. 12, oh).

The order of arrangement of the onchospheric hooks is indi-

vidual. In some specimens they are situated at the end of the

bladder, while in others they are at the side. In some the arrange-

ment is in a group, while in others they are in pairs. Some of

my specimens show a pair of embryonic hooks in the layers of

MORPHOLOGY OF CESTODES FROM POULTRY 33

the cyst between the base of the neck and the attachment of the

bladder, while the other two pairs of hooks are located in the

bladder.

The cavity of the bladder is formed apparently by a splitting

or hollowing out of the cells of the tail, because the wall is con-

tinuous and of the same histological structure. The wall of the

bladder is constructed of two layers, an inner cell layer and an

outer cuticular layer. The outer cuticular layer is more or less

striated on account of minute fibrils uniting it with the inner cell

layer. Histologically, the structure of the inner layer is con-

structed of somewhat granular substance arranged in fibers form-

ing a network which encloses clear spherical cells with large nuclei

(Fig. 13). Outside of the cuticular layer is located the peritoneum

of the host which lies upon the bladder and surrounds it as well

as the cyst.

C. COMPARISON OF ADULT AND CYSTICERCUS

A comparative study of the adult and the cysticercoid shows

the likeness which exists between them. The presence of the

same number of hooks, having exactly the same size and shape

as seen by comparing Figures 8 and 9. Minute hooklets of the

same size are present in both cysticercoid and adult lining the suck-

ers, the entire surface of the scolex and a part of the neck region.

Rosseter (1891: 365) shows that the hooks on the rostellum and

suckers of Echinocotylus Rosseteri undergo no changes during

the act of transition from cysticercus to adult stage. The rostellar

sac is of the same general shape in both. The head of the rostel-

lum is not expanded in the cysticercoid as in the adult because it

has not functioned as yet. This corresponds to figures as shown

by Schmidt (1894, Pl. VI, Fig. A) of the cysticercoid and Krabbe

(1869, Pl. VI, Fig. 114) of the adult of Drepanidotenia anatina,

and by Grassi and Rovelli (1892, Pl. IV, Fig. 7, 8) of the cysti-

cercoid and Blanchard (1891: 16) of the scolex of Davainea

proglottina. No measurements are given for the rostellum of

either the cysticercoid or the adult by the above authors.

There is a great deal of difference in the size of the scolex

between the cysticercoid and the adult. In my specimens the

,

34 JOHN E. GUTBERLET

scolex of the adult is between four and five times as large as that

of the cysticercoid. The scolex of the cysticercoid has as yet

not functioned so that the musculature of the organs is not devel-

oped as in the adult, consequently is not nearly as massive. The

cells also are smaller than those of the adult.

Schmidt (1894: 10, 44) shows that the adult scolex of Dre-

panidotenia anatina is about three times as large as that of the

cysticercoid. He also states that the size of the cysticercoid may

vary with the size of its host.

Different forms become modified in changing from the inter-

mediate to the adult hosts as shown by Schmidt (1894) in Dre-

panidotenia anatina, Rosseter (1891) in Echinocotylus Rosseteri,

and Grassi and Rovelli (1892) in Davainea proglottina.

Onchospheric hooks in the wall of the tail are the same size

(18) and shape as those of the embryos found in the mature

proglottids.

A consideration of these factors of morphological significance

which demonstrate the resemblances between the cysticercoid and

adult, indicates clearly that this cysticercoid is the intermediate

stage of Choanotenia infundibuliformis.

OTHER CHICKEN CESTODES IN THE UNITED STATES

1. Davainea tetragona (Molin 1858) Blanchard 1891

Diagnosis: Length 10 to 250 mm. by 1 to 2.5 mm. in breadth,

varying with state of contraction. Scolex (Fig. 19) 175 to 215p

in diameter, with retractile rostellum 25 to 50» in diameter, armed

with single row of about 100 hooks. Rostellar hooks (Fig. 20)

6 to 9u long through longest axis, hammer-shaped, with long ven-

tral root and short dorsal root, prong short and recurved. Suckers

oval, 60 to 110y in diameter, armed with 8 to 10 rows of small

hooks of various sizes. Acetabular hooks (Fig. 21) range in

size from 4 to 8 through longest axis, having thorn-like

prong, short dorsal root, and longer flattened ventral root, which

is shorter than prong. Neck long and slender, but often as broad

as head. Segments trapezoidal and imbricate, edges of strobila

serrate. Oldest segments usually longer than broad, often bell-

MORPHOLOGY OF CESTODES FROM POULTRY 35

shaped. Genital pores usually unilateral, situated one in each

segment, at or in front of middle of lateral margin, frequently

marked off by papilla. Male and female canals pass on dorsal

side of nerve and excretory. vessels.

Male Reproductive Organs: Testes 20 to 30 in median field

surrounding female organs, most of them lying on aporose side

of latter. Vas deferens situated in anterior third of segment,

beginning near median line, and extending in much convoluted

course laterally to base of cirrus pouch which it enters and, after

a few coils in basal portion of latter, passes into cirrus. Cirrus

pouch pyriform, 75 to 100 in length. Basal portion surrounded

by prominent layer of longitudinal muscle fibers, neck with thick

layer of transverse fibers. Cirrus without apparent spines.

Female Reproductive Organs: Ovary in middle of segment.

Yolk gland posterior to ovary, irregularly reniform, slightly longer

in its transverse axis, about 100 in diameter. Shell gland promi-

nent, 50. in diameter, immediately in front of yolk gland. Vagina

begins at genital pore, posterior to opening of cirrus pouch, at

first very slender but at distance of 15 to 254 from genital pore

swells out into thick-walled tube, functioning as seminal recep-

tacle. This extends transversely across segment and joins oviduct

on dorsal side of ovary near median line. Oviduct, after being

joined in shell gland by vitelline duct, proceeds forward and ends

on dorsal side of ovary. Definite and persistent uterus not devel-

oped. Eggs pass from distal end of oviduct, become imbedded

in fibrous and granular or gelatinous mass which fills up most of

segment. This mass divides into 50 to 100 portions to form egg

capsules, each surrounded by membrane and containing 6 to 12

or more eggs. Egg is surrounded by three envelopes,—inner, close

to onchosphere, often scarcely visible; middle layer or envelope

much folded, giving appearance of network between inner and

outer membranes; and smooth outer envelope. The onchosphere

measures 10 to 15» in diameter; the outer envelope measures from

25 to 50p in diameter.

One point noted here that has not been mentioned before by

other authors is that the genital pores are irregularly alternate.

,

36 JOHN E. GUTBERLET

They are usually unilateral. The existence of this irregularly —

alternate occurrence of the genital pores may be an anomaly, but

it is rather frequent for such a condition.

2. Davainea echinobothrida (Megnin 1880) Blanchard 1891

Diagnosis: Length up to 250mm; width 1 to 4 mm. Head

(Fig. 22) 0.25 to 0.45 mm. in diameter, with retractile rostellum

100 to 150 in diameter, armed with crown of about 200 hooks

arranged in two rows. Suckers round or oval, 90 to 200u in diam-

eter, armed with 8 to 10 rows of hooks. Rostellar hooks (Fig.

23) similar to those of Davainea tetragona, but larger, measuring

10 to 13 in length. Acetabular hooks (Fig. 24) likewise similar

to those of D. tetragona, but also larger; size variable, smallest

being 7 or 8p in length and largest measuring from 14 to 16x.

Neck thicker and generally shorter than D. tetragona, nearly equal

to width of head. Strobila resembling that of D. tetragona, but

serrate border more pronounced. Oldest segments in preserved

specimens also differ from those of D. tetragona, being less elon-

gate and frequently marked by median constriction. Owing to

this constriction adjacent borders of most posterior segments pull

apart in median line and remain joined only at sides, giving rise

to median series of openings through posterior portion of strobila.

Genital pores irregularly alternate, or sometimes almost entirely

unilateral, situated one in each segment posterior to middle of

lateral margin. Male and female canals pass on dorsal side of

nerve and excretory vessels.

Male Reproductive Organs: Testes 20 to 30, arranged in

median field surrounding female glands as in D. tetragona. Vas

deferens lies in anterior third of segment much as in D. tetragona.

Cirrus pouch flask-shaped, 130 to 180» in length. Basal portion

elobular or ovoid, surrounded by layer, about 10» thick, of longi-

tudinal muscle fibers inside of which is a layer about 12 thick

of transverse fibers. Neck of pouch measures 50p to 75y in length

by 15 to 20n in diameter, surrounded by layer of transverse fibers

thickened at distal end to form sphincter. According to Mégnin,

the cirrus is armed with minute spines.

Female Reproductive Organs: Female organs same as in

Davainea tetragona, and onchospheres (Fig. 25) are also similar

MORPHOLOGY OF CESTODES FROM POULTRY 37

in structure and size, 14 to 15 in diameter. Onchospheric hooks

6 to 7p long. Egg capsules in groups of 6 to 12 or more, em-

bedded in a fibrous gelatinous mass.

In the living specimens very little difference can be noticed

except in size of the species D. tetragona and D. echinobothrida.

They are both quite transparent and appear much alike in every

respect in external appearance, except that D. tetragona is slightly

more transparent, while the oldest segments of D. echinobothrida

have very distinct median constrictions between them, appearing

almost as a series of openings.

The chief differences between D. tetragona and D. echinoboth-

rida are that in the latter the animal is larger, the hooks are more

numerous and larger, and the structure and size of the cirrus

pouches show a very distinct difference. There is also a difference

in the pathological effect of these spiny-suckered forms. D. echino-

bothrida produces large nodules or ulcers in the intestinal

wall. The scolex bores through the mucosa of the intestine and

in some cases nearly through the muscular coats. This disease

in fowls is termed “nodular teniasis”, as described by Moore

(1895: 1), and is often mistaken for other diseases.

3. Davainea cesticillus (Molin 1858) Blanchard 1891

Diagnosis: Length 10 to 125 mm. Maximum width 1.5 to

3mm. Head cylindrical (Fig. 28), sometimes spheriodal, 0.3 to

0.6 mm. wide and 0.2 to 0.4 mm. long. Suckers unarmed, about

100, in diameter. Rostellum broad and flat or hemispherical, 0.25

to 0.35 mm. wide, armed with a crown of 200 to 300 hooks which

are very unstable and easily lost, arranged in two ranks. Hooks

(Fig. 29) 8 to 12» long with short dorsal root and long ventral

root. Neck very short. Anterior segments three to five times

as broad as long; the following increase in size until they become

equal in length and breadth and finally even longer than broad;

borders overlapping. Genital pores irregularly alternate, one in

each segment, somewhat in front of middle of lateral margin in

young segments and nearer the middle in older segments. Vagina

and cirrus pouch pass dorsal of the two excretory canals and

nerve.

38 JOHN E. GUTBERLET

Male Reproductive Organs: Testes (Fig. 17, t) 20 to 30 in

number in posterior portion of segment. Vas deferens much

coiled before entering base of cirrus pouch, also coiled within latter.

Cirrus pouch ellipsoidal, 120 to 150% long by 55 to ZO wide.

Cirrus when protracted 10 in diameter, armed with minute spines,

and with bulbous enlargement 20u in diameter at its base, where

it becomes continuous with cirrus pouch.

Female Reproductive Organs: Vagina enlarged before reach-

ing median line into small seminal receptacle (Fig. 17, sr). Ovary

occupies middle field in front of testes. Yolk gland and_ shell

gland posterior to ovary, ventral and dorsal, respectively, in rela-

tive position. Uterus at first in front of ovary as cord of cells;

gradually increasing in size, finally occupies most of segment and

frequently extends laterally beyond excretory canals. In oldest

proglottids it becomes divided into compartments, or capsules,

each containing a single egg. Embryo (Fig. 30) 36 by 27» in

diameter, with very thin membrane closely adherent to surface.

Embryo further enveloped by thicker, smooth fibrous membrane,

oval in shape, 45 to 40u in diameter, with filament at each pole

attaching to thin outer wrinkled membrane about 35 by 50, in diam-

eter: finally egg is surrounded by capsule composed of outer and

inner membrane, latter closely adherent to or fused with outer

egg membrane; and former more or less widely separated from

latter and connected with it by number of septa.

One of the principal points noted here that is not mentioned

by other authors is the size of the rostellar hooks. In my speci-

mens they seem to be somewhat larger than those described by

others. They have been described as being 8 to 10» long, while

my forms show many of them to be distinctly 12» in length. A

second point noted here is the method of the development of the

uterus. The uterus develops in front of the ovary. It first ap-

pears as a solid cord of cells connected with the united ducts of

the ovary, shell gland, and yolk gland. The solid cord of cells

which later gives rise to the uterus becomes hollow and appears

as a blind sac or tube. This then grows in size, forming pockets,

and finally fills up the entire proglottid.

MORPHOLOGY OF CESTODES FROM POULTRY 39

This form is one of the most common chicken tapeworms

and is the most easily recognized. It can be identified by the head

with its broad, flat rostellum which shows up very prominently ;

the width of the most anterior segments is usually equal to or

greater than the width of the head, and the eggs are distributed

in individual egg capsules in mature proglottids.

4. Hymenolepis carioca (Magalhaes 1898) Ransom 1902

Diagnosis: Length 30 to 80mm. Breadth at neck 75 to 150u,

at posterior end 0.5 to 0.7 mm. Segments three to five times or

more broader than long throughout strobila. Head (Fig. 26)

flattened dorso-ventrally, 140 to 160» long, 150 to 215» wide and

100 to 140 thick. Suckers shallow, 70 to 90u in diameter, un-

armed. Rostellum unarmed; in retracted position 25 to 40y in

diameter and 90 to 100,» in length, with small pocket opening to

exterior in anterior position. Unsegmented neck portion of strobila

0.6 to 1.5 mm. long. Genital pores almost entirely unilateral, a

single pore being located in each segment slightly in front of middle

of right-hand margin.

Male Reproductive Organs: Testicles three in number, nor-

mally two on left and one on right of median line. On dorsal

side of inner end of cirrus pouch vas deferens is swollen into

prominent seminal vesicle (Fig. 18, sv) which may attain a size

of 70 by 50y. Cirrus pouch (Fig. 18, cp) in sexually mature

segments 120 to 175 long by 15 to 18 in diameter ; almost cylindri-

cal, slightly curved toward ventral surface of segment; on outer

surface about 20 longitudinal muscle bands, 2 to 3p in thickness,

very prominent in cross section; vas deferens enlarged within

cirrus pouch to form small seminal reservoir occupying proximal

two-thirds of pouch; distal third of portion of vas deferens within

pouch very slender, about lp in diameter and functions as cirrus.

Genital cloaca 12 to 36p deep.

Female Reproductive Organs: Opening of vagina in floor of

genital cloaca, ventral and posterior to cirrus opening. First por-

tion of vagina very narrow, 1p in diameter. Small vaginal sphinc-

ter 8 to 10» from vaginal opening. On inner side of sphincter

vagina gradually increases in diameter, and in sexually mature

,

40 JOHN E. GUTBERLET

segments swollen into prominent seminal receptacle (Fig. 18, sr)

which extends forward to anterior border of segment and inward

considerable ‘distance beyond proximal end of cirrus pouch. Ovary

faintly bilobed or trilobed in posterior half of proglottid. Yolk

gland spherical or ovoid, 30 to 40n in diameter, situated near median

line of segment, posterior and dorsal of ovary. Uterus at first

solid cord of cells extending transversely across segment along

anterior border of ovary; becomes hollowed out and grows back-

ward on dorsal side of ovary; in gravid segments occupies nearly

entire segment and filled with eggs. Eggs (Fig. 27) in gravid

uterus spherical or oval, with four thin membranes, the two middle

membranes often approximate to form thick layer which shows

somewhat of a cellular or coarse granular structure. Diameter of

outer membrane 36 by 36p to 75 by 7Ou, of: outer middle mem-

brane 30 by 30p to 65 by 60, of inner middle membrane 26 by

26p to 40 by 35y, of inner membrane 24 by 16p to 29 by 21p. This

membrane often lies so close to onchosphere that it can scarcely

be distinguished from edge of embryo. Onchosphere is 18 by 14

to 27 by 19 in diameter; length of embryonal hooks 10 to 12p.

This form is thread-like and usually occurs in great numbers.

It is very delicate and fragile and can be recognized by that fact

alone, as it is the most fragile of the chicken forms known.

SUMMARY

1. By morphological comparison of the cysticercoids produced

experimentally in flies and adult of Choanataenia infundtbuliformis

they are shown to be identical.

2. Morphological points noted are the presence of minute

hooklets on the suckers and entire surface of scolex in Choanatenia

infundibuliformis. The manner of development of uterus in the

same species is by means of a blind tube which grows in size,

forming pockets, and later breaks up into small compartments.

In Davainea tetragona the genital pores were found to occur irreg-

ularly alternate in the proglottids. The hooks on the rostellum

of Davainea cesticillus were found to vary in length from 8 to

12». The uterus in development first appears as a solid cord of

cells which becomes hollow and in growing forms pockets, filling

the entire proglottid.

MORPHOLOGY OF CESTODES FROM POULTRY 41

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Jahrb. Anat., 13: 359-384.

MORPHOLOGY OF CESTODES FROM POULTRY 43

EXPLANATION OF PLATES

Unless otherwise stated all drawing were made with the aid of a camera

lucida.

ABBREVIATIONS

b—bladder rs—rostellar sac

c—cyst sg—shell gland

ca—primitive cavity sr—seminal receptacle

cn—connection of bladder with cyst sv—seminal vesicle

cp—cirrus pouch t—testes

dex—dorsal excretory canal “u—uterus

ex—excretory ring in scolex v—vitelline duct

o—ovary va—vagina

oh—onchospheric hooks vd—vas deferens

ov—oviduct vex—ventral excretory canal

r—rostellum y—yolk gland

PLATE V

CHOANOTAENIA INFUNDIBULIFORMIS

Fig. 1. Scolex much contracted. x40

Fig. 2. Scolex normal extension. x145

Fig. 3. Longitudinal section of scolex, showing rostellum and rostellar sac.

x425

Fig. 4. Section of portion of sucker, showing hooklets, 425

Fig. 5. Section of portion of wall of scolex, showing hooklets. x425

Fig. 6. Longitudinal nerve tract, showing nerve cells with processes. x650

PLaTEe VI

Fig. 7. A, B, C, D. Embryos from mature proglottid. x425

Fig. 8. Hooks from rostellum of adult. x425

CYSTICERCUS OF CHOANOTAENIA INFUNDIBULIFORMIS

Fig. 9. Hooks from rostellum of cysticercus. x425

Fig. 10. Section through scolex, showing rostellum with hooks and rostellar

sac, x425

Fig. 11. Section through scolex and cyst, showing suckers with hooklets,

structure of cyst and primitive cavity between layers of cyst. x425

Fig. 12. Reconstruction of cysticercus with cyst and bladder or tail, showing

scolex in cyst and onchospheric hooks in bladder. x145

Fig. 13. Section of wall of bladder, showing histological structure and

peritoneum of host. x425

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig.

. 14.

15.

16.

17,

18.

20.

JOHN E. GUTBERLET

PiateE VII

Choanotaenia infundibuliformis. Reconstruction of mature pro-

glottid, showing reproductive organs, excretory vessels, and nerve.

x145

C. infundibuliformis. Reconstruction of cirrus pouch showing

cirrus and vas deferens, also part of vagina in connection with

cloaca. x310

C. infundibuliformis. Reconstruction of female reproductive or-

gans, showing part of ovary, yolk gland, shell gland, oviduct,

vitelline duct, uterus, and connection of ducts with uterus and

seminal receptacle. x310

Davainea cesticillus. Reconstruction of mature proglottid, showing

reproductive organs and excretory vessels. x145

Hymenolepis carioca. Reconstruction of mature proglottids, show-

ing reproductive organs from ventral view. x145

Pirate VIII

Scolex of Davainea tetragona. x145

Hooks from rostellum of D. tetragona. x425

Hooks from suckers of D. tetragona. x425

Scolex of Davainea echinobothrida. x145

Hooks from rostellum of D. echinobothrida. x425

Hooks from suckers of D. echinobothrida. x425

Embryos of D. echinobothrida, showing capsule and fibrous gel-

atinous mass in which it is embedded. x425

Scolex of Hymenolepis carioca, after Ransom.

A, B, C, D. Embryos of Hymenolepis carioca, showing enveloping

membranes. x425

Scolex of Davainea cesticillus. Free-hand drawing of living spec-

imen well extended, showing rostellum.

Hooks from rostellum of D. cesticillus. x425

A, B, C, D. Embryos of D. cesticillus, showing enveloping mem-

branes. x425

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Pate VIII

A PRELIMINARY STUDY OF THE SPERMATOGENESIS

OF BELOSTOMA (ZAITHA) FLUMINEA

By A. M. CHICKERING

The study of Belostoma fluminea was begun during the sum-

mer of 1914 at the University of Wisconsin under the direction

of Prof. M. F. Guyer to whose help and criticism the writer owes

much. I also wish to take this opportunity to express my grati-

tude to Prof. H. D. Densmore of Beloit College for the loan of

expensive and indispensable apparatus.

MATERIAL AND METHODS

Belostoma fiuminea is the common, giant water bug of our

shallow ponds and slowly moving streams. This form is very

common in the region around Madison, Wisconsin and has been

taken in large numbers, especially during the month of July.

Nymphs and adult males, which are often taken bearing the

egg-cluster on their backs, were used to obtain the necessary ma-

terial. Some of the adults show the whole general history of

the germ cells from spermatogonia to mature spermatozoa with

great clearness. By careful study the seriation is placed beyond

reasonable doubt by virtue of the arrangement of the cells in cysts

in a nearly progressive series from one end of the testes to the other.

On account of their extreme delicacy and transparency some

trouble was experienced at the beginning in removing the testes

from their position in the abdominal cavity to the fixing fluid.

Later, however, this was overcome by squirting the fixing fluid

directly on to the testes after removal of the dorsal abdominal

wall. After a few moments the organs stood out sharply and

could be transferred easily to the final fixing fluid without injury.

The best results in fixing were obtained with Gilson’s and

Bouin’s fluids.

The iron-hematoxylin® method of staining has proven very

satisfactory for this work. Other stains have been tried with

,

46 A. M. CHICKERING

varying degrees of success but all the slides used in preparing this

paper were stained with Haidenhain’s iron-hematoxlyin. Sections

were cut from four to six p» in thickness.

Smears have been almost uniformly unsuccessful. In a few

cases smear slides of fair quality were obtained but as yet no care-

ful study has been made of them. The method of preparation as

described by Morse (’09) gave better results than any other. The

testes are simply removed to a slide and the cysts pricked or teased

gently. This allows the contents to run evenly over the slide -

which is afterwards dried and stained without the use of any

fixing fluid.

The works cited at the end of this paper are only those which

have been especially helpful to the writer in preparing this brief

paper. No attempt has been made to append a complete list of

papers on this subject.

SPERMATOGENESIS

I. Spermatogonial stages

The spermatogonial divisions are very numerous in this ma-

terial, particularly so in the testes taken from nymphs. But

usually the chromosomes are so crowded together in these division

stages as to prevent any accurate counting or study of the separate

chromosomes. In fact the writer has been able to find only four

metaphase plates in which the chromosomes could be effectively

studied. These were all found in the testes of a single specimen

and are probably undergoing final division before synapsis.

The two cells shown in figures 1 and 2, have the chromosomes

arranged in a very flat equatorial plate in a plane almost parallel

to the plane of the section. Both show twenty-four chromosomes,

and in each case there are four large bean-shaped chromosomes,

eighteen of intermediate size and spherical or ellipsoid in shape,

and two very small ones. Nearly all are connected to one or more

of the others by means of delicate filaments.

The other two cells mentioned above show, respectively,

twenty-three and twenty-two chromosomes. In the first case one

of the small pair is missing and in the second both are missing.

These are so small and the chromosomes so numerous that they

SPERMATOGENESIS IN BELOSTOMA 47

may be covered up easily and so escape detection. From the num-

ber and behavior of the chromosomes in the maturation divisions

one would expect the spermatogonial or unreduced number to be

twenty-four. The writer considers it fair to conclude from the

evidence at hand that such is the case.

It is quite evident from inspection of figures 1 and 2, that

three pairs of chromosomes may be identified at this stage. The

xy-pair, which becomes so apparent in the second maturation divi-

sion, is not distinguishable nor so far has it been possible to recog-

nize more pairs of chromosomes in this stage.

II, Synaptic and Post-Synaptic Stages

‘It has thus far been found impossible to obtain satisfactory

results with Belostoma in attempts to work out the history of the

chromosomes during synapsis and the early prophase stages of

the primary spermatocytes; hence no attempt will be made to

describe these in any detail, only a brief outline being given. I

hope, however, to obtain suitable smear material at a later date

and make a careful study of the stages necessarily slighted now.

Immediately following the last spermatogonial division the

chromosomes loosen up and flow together into a rather lightly

staining, confused network (Fig. 3). This stage is of short dura-

tion, passing quickly into what is probably a spireme stage but

since no suitable material is available no drawings have been made

from this point to synizesis (Fig. 4). The threads making up the

synaptic knot are so crowded and tangled that usually only the

ends of the threads can be seen projecting beyond the heavily

stained mass. The knot is usually placed at one pole of the nucleus

and often a plasmosome is visible in these stages.

After the synizesis stage the threads quickly spread apart

throughout the nucleus. They now appear very thick and heavy,

and stain more deeply than in the preceding stages (Fig. 5-6). The

plasmosome attains its maximum size during this stage and grad-

ually diminishes and finally disappears during the early prophases.

In the later part of this period some nuclei appear to

show a divided condition of the separate threads even in sections

and in the best smears the threads are distinctly divided by a longi-

tudinal cleft (Fig. 7). Usually in the sections there are shown

,

48 A. M. CHICKERING

two threads which are much longer and broader than any of the

rest, presumably corresponding to the two large chromosomes of

the first division and made up of the four bean-shaped spermat-

ogonial chromosomes.

No evidence has yet been adduced to show that the sex-chrom-

osomes in Belostoma are present in the form of chromatic nucleoli

during the growth period as described by Wilson (712) in the sperm-

atogenesis of Lygeus and Oncopeltus although the general history

of the chromosomes seems to be very similar to that of the two

’ forms mentioned.

Before the prophase stages begin there is interpolated a “con-

fused” stage which results from a fading out and ultimate disap-

pearance of the heavy, divided threads. This process gives rise

to a nucleus which is traversed throughout by a loose network of

chromatin material consisting of much finer, irregular threads the

boundaries of which can not be made out. This goes on from Fig-

ure 8 until the network is reduced to an exceedingly confused condi-

tion. In this condition the threads stain so lightly and are so inter-

laced as to make it impossible to see the separate elements at all.

This “confused” stage is of relatively long duration, but finally con-

densation starts and the network is reorganized into the tetrad

rods, rings and V’s (Fig. 9-9A).

III. Chromatoid Bodies

In the confused stage are clearly seen for the first time (fur-

ther work seems likely to disclose their presence earlier) bodies

which have been called the chromatoid bodies (Wilson 713 and

Fasten ’14).

The larger of these bodies which becomes very prominent

in the division of the primary spermatocyte attracted my attention

when the work on Belostoma was first started. It then seemed to

be an x-chromosome and for a time the work was carried on with

that idea. The reader will readily see the resemblance of figures

14-23 to several already published by numerous workers demon-

strating the presence of an odd chromosome. In the case here

presented this idea must be abandoned. The chromatoid bodies

are seen in Fig. 8 outside of the nuclear membrane and therefore

SPERMATOGENESIS IN BELOSTOMA 49

not directly connected with the chromatin elements. THfey are

never found within the spindle although they are sometimes so

close to the group of chromosomes that they are indistinguishable in

polar views of metaphase plates, and in this way sometimes are

very confusing in taking chromosome counts. They do not occur

in all cells and when present behave irregularly. With iron-hem-

atoxylin they are stained like the chromosomes.

IV. Primary Spermatocytes

In the early tetrad stages of the chromosomes two rings are

very large and prominent. They are in practically every cell and

seem to give rise to the two large chromosomes of the mature

spermatocyte by a decrease in the diameter and a closing up pro-

cess. There are other smaller rings sometimes showing but they

do not seem to be constant. The rods seem to shorten and thicken

to form the final chromosomes; the same process probably takes

place with the Vs, and the rings apparently close up to form such

tetrads as shown in Figs. 10-11. Such figures are very common

in my material and may be favorable for working out the details

of the changes taking place here.

All of these figures finally condense into dumb-bell shaped

bodies (Fig. 12). This shape is retained throughout the first div-

ision, the constriction marking the plane of cleavage.

Very shortly after the stage shown in the last figure the nuclear

membrane begins to break down, the spindle forms at the two

poles, the chromosomes take up a position in the equatorial plane

and the cell is ready for division.

The chromatoid bodies remain of about the same size until

the spindle begins to be formed and then a decided increase in the

size of at least one of them is plainly seen (Fig. 13-15.)

The stages from this point onward show with diagrammatic

clearness. There are thirteen chromosomes in the equatorial plate

of the primary spermatocyte. This number is one more than half

the spermatogonial number. The arrangement of chromosomes

is inconstant, no two plates showing the same placing with respect

to each other. There are two large, ten intermediate and one very

50 A. M. CHICKERING

small chromosomes, they all divide equally in this division, carrying

over thirteen in every case to the secondary spermatocytes (Figs.

14-24).

These stages have been carefully searched to find the sex-

chromosomes and to determine their behavior but without success.

The chromatoid bodies are seen here (Figs. 14-24) at their

maximum size. Usually there is only one present, but quite often

there are two and more rarely three. In a few cases four have

been seen. Occasionally one or more of the number has an irreg-

ular shape (Figs. 14, 20 and 22).

When division takes place these bodies are not apportioned

evenly but may all be retained in a single secondary spermatocyte,

or one or more may go into each. No regularity seems to obtain

in the distribution of these bodies. Given three or four of different

sizes and a large number of types of secondary spermatocytes may

be derived if classified on the basis of the kind and number of

chromatoid bodies they possess.

V. The Interkinesis

It seems to be a well established fact that in the interkinesis

there is no more than a slight pause between the telophase of the

first and the prophase of the second divisions. The chromosomes

are much crowded together, but enough is evident to show that

they retain their individuality and are not in any degree reorgan-

ized into a nucleus (Fig. 25). The centrosomes also divide in late

anaphase and are already well moved apart, accompanied by small

spindles, in the late telophase.

Whether the grouping of chromosomes is changed in this stage

is uncertain, but the probability is that the new grouping assumed

in the next metaphase takes place during the prophases of the

same division.

VI. Secondary spermatocytes

In the prophases of this division the spindle is very rapidly

built up while the chromosomes which were so crowded before

now spread apart and assume a grouping very different from that

in the first division. Eleven of the chromosomes are arranged in

a circle at the equator of the spindle while two remain in the center

SPERMATOGENESIS IN BELOSTOMA 51

of the circle forming an xy-pair of sex-chromosomes. In polar

views only twelve chromosomes are usually visible (Figs. 26-28).

Lateral views of the same stage show however, that what appears

to be a single chromosome in polar views is in reality the xy-pair,

the members of which are united end to end. (Fig. 29).

All of the stages through inter-kinesis leading up to the meta-

phase in which the sex-chromosomes are seen united have been

studied to see how complete the conjugation between the two is

effected, and such a process seems to be limited to a simple end

to end union as described above. This union exists only for a short

time before the final separation and seems to take place while the

chromosomes are rearranging themselves in their new grouping

during the later prophase stages.

By a comparative study of Figs. 23-25, and 29-30, it will be

seen readily that a rotation of each chromosome through about

ninety degrees takes place while the spindle is being formed, so

that the long axis of each becomes parallel instead of perpendicular

to the long axis of the spindle. A rotation of the entire group

may also take place as described for Oncopeltus and Lygeus (Wil-

son *10) although it seems more probable that the virtual rotation

is accomplished by the relative change in position of the separate

chromosomes as they assume their new grouping.

In the latter part of this period the sex-chromosomes have

separated and are on their way to the opposite poles of the spindle

before the others have even started to divide at all (Fig. 30).

This aptitude for the sex-chromosomes seems to be a common

phenomenon and has been described by numerous workers.

The chromatoid bodies present about the same appearance

as in the primary spermatocytes. There are many cells without any

chromatoid body, many more with only one large one, and others

with two or three.

VII. The Spermatids

When division of the secondary spermatocytes takes place

twelve chromosomes are delivered to each spermatid, but one-half

of them receives eleven ordinary chromosomes plus the x-chromo-

,

LN, A. M. CHICKERING

somes while the other half receives eleven plus the y-chromosome

(Figs. 32-34).

In studying the cysts containing spermatids it is very evident

that those containing no chromatoid bodies are most numerous,

those with one fairly common and those with two or more are

much less common. In general, too, the size of these bodies is

somewhat less than in the primary spermatocyte although occa-

sionally one large one seems to be retained throughout at its maxi-

mum size (Figs. 35-38).

VIII. Summary

1. The spermatogonial number of chromosomes in Belostoma

(Zaitha) fluminea is twenty-four.

2. Only general facts have been determined in regard to sy-

napsis and the post-synaptic stages. During the post-synaptic

period a double nature of the chromosome threads is evident.

3. There is a “confused” stage just previous to the prophases

of the first division.

4. The chromatoid bodies appear in this “confused” stage

for the first time. Proof that they originate from the cytoplasm

is not lacking because they are plainly seen outside of the nuclear

membrane in this stage.

5. Tetrads appear in the form of rings, Vs, and rods, and all

become dumb-bell shaped, by continued condensation, at the time

that they enter the spindle.

6. The first maturation division is an equational division.

Polar views show thirteen chromosomes, which number is one-

half the spermatogonial number plus one.

7. The chromatoid bodies are at their maximum size in this

and the following division and generally grow smaller from that

point onward.

8. The interkinesis is of short duration. No nuclear vacuole

is formed, the chromosomes maintaining their individuality

throughout.

9. When the chromosomes arrange themselves in the meta-

phase of the second division an entirely new arrangement is

assumed and an xy-pair of sex-chromosomes can be identified.

SPERMATOGENESIS IN BELOSTOMA 53

10. Twelve chromosomes are delivered to each spermatid in

the second division, one-half receive in addition to the eleven ordi-

nary chromosomes an x- and the other half a y-chromosome.

11. The chromatoid -bodies behave irregularly all along.

Some spermatids have none, others have one and still others in

decreasing proportions have two or three.

54 A. M. CHICKERING

PAPERS CITED

Fasten, N.

1914. Spermatogenesis of the American Crayfish. Jour. Morph., vol. 25,

no. 4.

Morse, M.

1909. The nuclear components of the sex-cells in four species of cock-

roaches. Arch. f. Zellforsch., Bd. 3.

Witson, E. B.

1912. Studies on chromosomes. VIII.

Observations on the maturation phenomena in certain Hemiptera and

other forms, with considerations of synapsis and reduction. Jour. Exp.

Zool. vol. 13.

1913. A chromatoid body simulating an accessory chromosome in Pen-

tatoma. Biol. Bull., vol. 24.

Beloit College.

SPERMATOGENESIS IN BELOSTOMA 55

EXPLANATION OF PLATES

All figures are from Belostoma (Zaitha) fluminea are drawn with a

camera lucida and are magnified about 1350 diameters. Unless otherwise

stated the figures are not intended to show all the nuclear components.

Piate IX

1-2, Polar views of spermatogonial metaphases, showing twenty-four

chromosones.

3. Spermatogonial telophase (probably the last spermatogonial division).

4. Synizesis stage with a plasmosome.

5-6. Post-synaptic nuclei showing the heavy undivided chromosome

threads and plasmosomes,

7. A little later stage showing the divided threads. From a smear-

preparation. The cell is somewhat distorted.

8. The confused stage, showing three chromatoid bodies outside of

the nuclear membrane.

9-9A. About middle prophase of the first spermatocyte division, showing

the various forms of the chromosomes during condensation, and the chro-

matoid bodies.

10, Later prophase of the same division, showing the tetrads and only

one chromatoid body.

11. A very clear tetrad.

PLATE X

12. A late prophase of the first division showing the chromosomes

organized into dumb-bell forms.

13, Very late prophase, showing all the chromosomes and two

chromatoid bodies.

14-17. Polar views of metaphases of the first division, showing thirteen

chromosomes and either one, two, or no chromatoid bodies,

18-21. Lateral views of the same stage with a varying number of

chromatoid bodies.

22-23. Anaphases of the first division illustrating the irregularity in

the behavior of the chromatoid bodies during division of the cell.

PLaTe XI

24. Telophase of the first division. Here the two secondary spermato-

cytes have each received one chromatoid body. The four small bodies are

the controsomes already divided preparatory to the next division.

,

56 A. M. CHICKERING

25. Polar view of the same, showing the crowded condition of the

chromosomes.

26-28. Polar views of secondary spermatocytes. All the ordinary

chromosomes are here arranged in a circle with the sex-chromosomes in the

center and chromatoid bodies without the circle.

29-30. Lateral views of the same, showing the xy-pair of sex-chrom-

osomes in the center.

31. Same stage without the sex-chromosomes.

32. Anaphase of the second division, showing the x- and y- chromo-

somes going into different spermatoids and slightly in advance of the others.

33-34. Polar views of the same, showing the small y- and the larger

x- chromosomes in different spermatids. These cells were somewhat tilted

so that in drawing the sex-chromosomes are made to appear displaced from

their normal position.

35. Polar view of a spermatid with the chromosomes crowded in

telophase, and two chromatoid bodies.

36. Lateral view of the same stage showing one spermatid receiving

three chromatoid bodies and the other, none.

37-38. Later views of spermatids just before metamorphosis starts.

10

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DEPARTMENT OF NOTES, REVIEWS, ETC.

It is the purpose, in this department, to present from time to time brief original

notes, both of methods of work and of results, by members of the Society. All

members are invited to submit such items. In the absence of these there will be given a

few brief abstracts of recent work of more general interest to students and teachers.

There will be no attempt to make these abstracts exhaustive. They will illustrate progress

without attempting to define it, and will thus give to the teacher current illustrations, and

to the isolated student suggestions of suitable fields of investigation.—[Editor.]

A SYSTEM FOR RECORDING CYTOLOGICAL MATERIAL, SLIDES AND

LOCATIONS ON THE SLIDES

The following contribution is offered in full recognition of the

fact that many cytologists already have in use excellent methods of

recording their material and slides. Indeed many of the most

essential details of the present system of recording slides have been

taken over from a method in use by McClung, for which privilege

the writer acknowledges his indebtedness. The system to be

described has stood the test of the writer’s use in all par-

ticulars and it is offered here in hope that it may serve as a

suggestion for cytologists, who as yet have no recording method,

on which to base a. system serving their own particular needs. If

the scheme here outlined is impractical for certain workers this

note will at least serve to indicate the requirements that a cytological

recording method must meet to be really efficient.

Two sets of cards are used, one to record the gross material

and the other the slides and locations on the slides. On the former

card (Fig. 1) are all the notes concerning the material from the

fresh condition until it is embedded. On this card is to be found:

1. the serial lot number.

2. the material, the animal or plant from which it was taken, the

age and other notes of possible interest.

place of collection and condition of obtaining the material.

dates of fixation.

fixing fluid and the temperature the fluid was used at.

time in fluid.

washing and dehydration.

clearing methods used.

embedding methods and materials.

location of embedded material.

DOWPNAMAW

_

58 NOTES, REVIEWS, ETC.

Under “Dehydration” in Fig. 1 the time the material remains in

each grade of alcohol is recorded beneath that grade. In case the

more recent practice is used (not yet published) of displacing the

water with alcohol drop by drop an arrow is drawn, as indicated, to

the percentage of alcohol the material is in at the end of the dis-

placement. If the tissue was preserved in 70% alcohol then an

arrow would be drawn to “70%” and later when the dehydration

is continued a second arrow would be drawn to the grade at the

BOT Veske W CO- Katlyimn Nee

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CAGE HGscclen efLix Water 0 | 50% | 70% 807%, I5fe 00%

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end of the series. The writer embeds his material immediately as

in the long run it saves considerable time and tissue in paraffin is

much easier to carry about the country than in bottles. The material

under each lot number is usually embedded in a petri dish (the lot

number on a small piece of paper is embedded with the material).

The disk of paraffin after removal from the petri dish is wrapped

in wax paper and filed in a 3x5 cardboard filing case behind an index

AMERICAN MICROSCOPICAL SOCIETY 59

card bearing the lot number. In this way the material is compact

_and easy to get at.

On the second set of cards is to be found:

1. lot number.

2. slide number.

3. number of box in which slide is located.

4. stain used.

5. what is to be found on the slide.

6. thickness of sections.

7. condition of slide (i. e. good fixation or stain).

8. location of favorable areas on the slide.

9. notes concerning certain locations.

10. areas that have been drawn.

11. areas that have been photographed.

12. areas that have been drawn or photographed and used for pub-

lication.

The number is scratched on each slide of the series. If sperma-

togenesis is being worked upon one card is devoted to a single phase

in the process found on a particular slide. Similar phases on other

slides have their own cards. This card is labeled as shown in Fig. 2

under “Shows”. The same slide may therefore have several cards

devoted to it should it show more than a single phase. These cards

are filed first behind an index card bearing the lot number and then

in numerical order behind index cards bearing the phase name of

the particular stage they happen to represent. When the observa-

tions do not deal with spermatogenesis then, of course, the cards

are classified according to the special need.

As can be seen in Fig. 2 there is a place for forty readings.

The right hand reading of the mechanical stage is placed above the

short line, the horizontal reading is put beneath it. The slide is

first searched with a low power lens and readings of apparently

favorable locations are put down. Afterwards these locations are

tested with the oil immersion lens and either crossed out or drawn.

When the figure is drawn the location is circled as shown in Fig. 2.

Any notes that are to be made are indicated by the figures in the

space to the right of the readings. These numbers refer to cor-

responding numbers on the back of the cards under which the

notes are written. Small sketches may also be put in these spaces

,

60 NOTES, REVIEWS, ETC.

to recall what the reading is of. When the plates have been pre-

pared for publication the figure number is entered in the square

opposite the reading. When the cell has been photographed this

information is also placed here with the number of the photo-

Box | Stain thew Rasa atin nl.

3O

Thickness Conpitron

&

LOCATIONS.

graph. With these records should the plates be lost or when the

original of a figure is to be examined the location on the slide may

readily be found.

With the records on these cards before him the investigator

has all his data well in hand for the preparation of his paper.

Zoological Laboratory, Rospert T. HANCE.

University of Pennsylvania.

A MINIATURE DARK ROOM FOR USE WITH THE MICROSCOPE

All microscopists prefer to work either at night or in a dark-

ened room. Using the microscope under such conditions does

away with the strain to which both the observing and the unused

eye are subjected by the side light—i. e., light coming from sources

AMERICAN MICROSCOPICAL SOCIETY 61

other than through the tube. When working in darkened sur-

roundings the effect is that of looking at a picture on a screen.

The image appears brighter and objects become clear that under

the usual conditions are scarcely visible.

For several years the writer has been trying to devise some

method to control the light perfectly and to do this without neces-

sitating the darkening the whole room. It is desirable that any

apparatus for the purpose should weigh little and (for ease in carry-

ing from one place to another), it should be simple to take apart.

It should, of course, be adaptable to every condition. For further

convenience of the worker definite places should be present in

such an apparatus for the usual microscopical accessories—pens,

pencils, drawing and memorandum cards and lens paper.

The following description is of a miniature dark room for use

with the microscope fulfilling these requirements. It was de-

signed and made by the writer last fall and, after a year’s use, he

has found it to be exceedingly practical in eliminating all the strain

that results when the eye is unshielded. In this darkened enclosure

the eye not in use is at perfect rest. Moreover for drawing the

light may be controlled so that it is possible always to have light of

the same intensity directed on the drawing paper.

Description

Figure 1.

A. Base—%-inch white pine 12x18 inches with a binder of

the same wood across each end to prevent warping.

B. Uprights—dowel sticks 1 inch in diameter cut to 18 inches

in length.

C-C’. Rods—common telescoping curtain rods. Each of the

rods C’ is cut 8 inches from the end that ordinarily would be used

to fasten it to the window. C is formed of the remainder, of the

part between the ends.

D. Wire—a piece of annealed wire % inch in diameter about

4% feet long bent as shown.

To assemble :—one two inch screw fastens each upright to the

base. The upright on the right can be seen to have two angle irons

aiding in its support but this is only necessary when the fan is

62 NOTES, REVIEWS, ETC.

added. Holes are drilled in both uprights to correspond to the

diameter of C which is inserted in them. The rods C’ are attached

by one end to the tops of the uprights by a screw through the eye-

let in the rod. Through the eyelet at the opposite end a small rod

is passed as shown to prevent the curtains from slipping off. The

wire D is fastened to the outer sides of the uprights by means of

a single round head screw passed through each flattened end. All

the wood and metal work is painted a dead black.

For many valuable suggestions on the design of the curtains

and for the excellence of their construction I am indebted to my

mother. (See figure 2).

The curtains suspended from the rods C and C’ are in four

parts, all overlapping each other and fastening together with spring

snaps. They are made of the heaviest grade of black sateer

doubled. On the right hand curtain are pockets for pencils and

cards. On the left side is a pocket for lens paper. The pocket is

provided with a flap to exclude the dust. The upper curtain car-

ried on the wire D is of single thickness. The central curtain is in

two parts so that they may be separated to permit light to fall on

the drawing board. The left hand curtain of the central set has a

rectangle 1 inch wide by 5 inches high cut from the center of the

basal portion. Across the top of this aperture is stitched a flap of

double thickness, 3%4 inches wide by 5% inches in length. To one

corner of the loose end of the flap is attached a tape which passes

around the tube of the microscope and fastens to the other corner

of the flap by means of a spring snap.

With the microscope surrounded by these curtains it is im-

possible to read the figures on the mechanical stage and so the small

light (fig. 1 E) was installed. This can be adjusted by means of

sliding rods locked with winged nuts to hang directly over the

stage. The lamp arm is attached to the right hand upright by

means of a collar made of two pieces of brass stripping fastened on

either side of the pillar with a thumb screw. The lamp is a small

tungsten bulb set in a porcelain socket. The shade or reflector,

shown in the photograph, was taken from an old tubular flash light.

A small three-cell pocket battery furnishes the current which is

PLATE XII

PuatTE XIII

AMERICAN MICROSCOPICAL SOCIETY 63

controlled by a push button at the left of the microscope. The

same battery has lasted for very nearly a year now without visible

signs of weakening.

The fan shown in both photographs is a toy motor equipped

with a 4% inch blade. The motor is operated on two dry cells.

It is fastened to a wooden base that is inserted in a slot in the up-

right and clamped tight by means of a winged nut. This fastening

permits the fan to be tilted up and down while the single screw

securing the fan to the base allows a left and right rotation. The

air current may thus be directed on any spot desired.

Operation

For microscope illumination with this dark room a concen-

trated filament mazda frosted globe is used. This globe is placed

behind the slit in the central curtain and the microscope is put in

position on the opposite side. The flap covering the slit is then

snapped about the tube of the microscope just above the nose piece.

The slit through which the light comes is so narrow that the stage

of the microscope effectively shields the eye from the light coming

through the lower part of the slit while the flap takes care of all

other dispersion.

In the average room having windows on only one wall the

side curtains can be left wide apart. In places where the worker

is almost surrounded by windows it is of advantage to draw the

side curtains so close that there is just room for the observer’s

head to enter. The telescoping rods supporting the side curtains

permit these to be narrowed or widened to suit the circumstances.

The top curtain works to or from the microscopist and is frequent-

ly convenient in cutting out the light from the upper parts of the

windows.

Light on the drawing paper is obtained by separating the lower

portions of the central curtains from each other and fastening them

back. The bulb illuminating the microscope then throws its light

over the right hand side of the base. A constant intensity of illum-

ination is in this way assured.

The fan is a luxury—possibly an unnecessary one, but in very

warm weather or on days when a few flies persist in maintaining

r ,

64 NOTES, REVIEWS, ETC.

their position at all hazards on top of the writer’s head he has not

been at all skeptical as to whether the luxury was unnecessary or

not.

Zoological Laboratory, Rosert T. HANCE.

University of Pennsylvania.

NOTES ON A NEW SPECIES OF LOXODES (EHRBG.) ?

In the course of work upon the distribution of fresh-water

protozoa in the southeastern part of Massachusetts many species

were found which could not be named according to the available

classifications. This is true of various species of the genus Lox-

odes.

Loxodes belongs to the class of Infusoria and to the sub-class

Ciliata ; that is, the protozoon is provided with cilia or sete during

all of its stages, but is free of flagella. This sub-class is divided

into a number of orders, Loxodes falling under the order of Holo-

tricha. This order includes the ciliata which possess but one kind

of cilia and show the anus and mouth conspicuously. The mem-

bers of the genus Loxodes show a hook-like projection on the an-

terior end which is bent to the left, and cilia cover nearly the entire

body. The body is flattened, slightly elongated and possesses a

well defined outer envelope of the cell or ectoplasm which is con-

stant in form. The dorsal surface is free from cilia, smoothed and

curved. The ventral surface is flat and well ciliated, with a mouth

on the left anterior edge which is at the bottom of a slit-like peris-

tome. Some writers claim this leads into a pharynx, the existence

of which I have not been able to see. The animal is a free swim-

mer and shows nuclei clearly.

The species under consideration has an average length of 60

microns and width of 16 microns. It is found in great numbers

among Oscillaria, associated with Nassula, Paramecium and roti-

fers. There was no evidence of its feeding upon the alge. Its

food consisted principally of small paramecia.

They may be narcotized for study by a .47% solution of cocaine

hydrochloride; though after about two minutes the animal slowly

assumes an oval shape, then becomes round and all evidence of

life ceases. The action of the narcotic was not so pronounced up-

AMERICAN MICROSCOPICAL SOCIETY - 65

on the paramecia and rotifers, for at the end of ten minutes loco-

motion was evident in these, although not so rapid as in the clear

water. ;

During swimming these ciliata have a spiral motion which is

to the right. Trichocysts were noted in the larger specimens, this

being limited to the posterior region. Some of them seemed to

possess contractile vacuoles while others did not. The anterior

end is hook-like but not a rostrum. In this respect it differs from

Loxodes rostrum (Mull.); the anterior end is also more blunt,

and the dorsal surface was more curved than in L. rostrum.

Further study upon this species and the genus is in progress.

Chadwick, N. Y. Etton R. Dartine.

ENTOMOLOGICAL NOTES

Variation nm Spermatozoa.—Zeleny and Senay (715, Journ.

Exp. Zool., 19:505-514) report results of studies on variation in

head length of spermatozoa in insects. This work is a continu-

ation of earlier studies by Zeleny and Faust, an abstract of which

appears in this journal (34:191). The following insects were

studied: Corizus lateralus, Leptocoris trivittatus, Reduviolus

ferus, Euschistus variolarius, Cosmopepla carnifex, Passalus cornu-

tus, and Berosus striatus. With the exception of Passalus cornu-

tus, all gave distinctly bimodal curves indicating the existence of

two distinct size groups of spermatozoa. The one exception yielded

a unimodal curve and is interpreted as indicating lack of distinc-

tion among the spermatozoa or else as having two groups which

differ so slightly from each other that a unimodal result is pro-

duced. Additional support is thus given to the belief that dimor-

phism in size of. spermatozoa is common among animals having

two chromosomal classes of spermatids, due to quantitative differ-

ences in chromosomal content.

Bibliographies—The Journal of Animal Behavior (5:407-461)

has issued its annual lists of literature pertaining to the behavior

of animals. Turner (pp. 415-445) has given a brief analysis of

the more important results which have appeared in the literature of

1914 and lists one hundred seven papers from American and foreign

sources which treat of the behavior of spiders and insects other

,

66 NOTES, REVIEWS, ETC.

than ants. The analysis of subject matter is very useful and the

list of titles, while not entirely complete, forms an important source

of information.

Differential Incidence of Bruchus—Harris (715, Journ. N. Y.

Ent. Soc., 23 :242-253) reports the results of a statistical study on

“differential incidence of the beetle Bruchus” in which the purpose

was to discover whether the characters of the bean pod, on which

the eggs of Bruchus are laid, determine, to any degree, the fre-

quency of infestation (“parasitization”). Examination of over

fourteen thousand pods, producing almost forty thousand seeds,

showed that the relative number of infested seeds is greater in pods

with larger numbers of ovules. Increase in percentage of infesta-

tion accompanies increase in the number of seeds matured per pod.

No relationship between the position of the seed in the pod and

liability of infestation was discovered. The hypothesis offered is

that since young pod size is correlated with the number of ovules

and the number of developing seeds, thus resulting, in the larger

pods, increased ease of foothold and additional facility for ovipo-

sition are made possible.

Respiration in Zygopterous Larve.—Calvert (715, Ent. News,

26 :435-447) summarizes the literature on the subject of the respir-

ation of zygopterous larve (Odonata). From compiled and or-

iginal data it appears that the oxygen demands of the animals are

satisfied, at least in part, by several modes of respiration. The

general body-surface, the caudal processes, the rectal epithelium,

certain spiracles, and, in some species, the lateral external tracheal

gills, all form functional parts of the respiratory system.

Behavior of the Ant-lion—Turner (15, Biol. Bull., 29 :277-

307) has studied the behavior of the ant-lion and finds, among

numerous other things, that the characteristic pits, which may be

found in any kind of dry friable soil in protected situations, are

constructed either by furrowing backward, producing a series of

concentric excavations, each deeper than the preceding and remov-

ing the soil with the head, or by the simple removal of the soil until

the sides of the pit become somewhat stable. Locomotion is invar-

iably backward, never forward. “Any invertebrate, be it insect,

arachnid, or crustacean, that happens to fall into the trap is accept-

AMERICAN MICROSCOPICAL SOCIETY 67

able as food.’ Letisimulation (death-feigning) often follows

rough handling or other similar treatment and, though variable in

duration, mutilation may frequently fail to produce response. No

well-defined relation appears to exist between the duration of the

feint and temperature, fasting, or strength of the stimulus.

Reaction of Epeira—Barrows (’15, Biol. Bull., 19:316-326)

finds that the large orb weaving spider, Epeira sclopetaria, orients

itself, when going from the center of the web to capture entangled

flies, in response to a vibratory stimulus. The stimulus can be sub-

mitted experimentally and produces the normal response, the latter

being analyzable into (1) the orientation, (2) the forward move-

ment, and (3) the attack on the vibrating object. Mutilation ex-

periments yielded evidence indicating the probability that the organs

used in detecting the vibratory stimulus are sense hairs on the

tarsi.

Regeneration.—Schmit-Jensen (’15, Smithsonian Report for

1914, pp. 523-536) made a study of homeeotic regeneration of the

antenne in a phasmid, Carausius morosus. A “spontaneous case

of substitutional homeesis” was noted among a lot of individuals

(nymphs) which had suffered from cannibalism. An antenna,

bitten off near the base, developed, after molting, a termination

consisting of a distinct tarsus-like segment with a large empodium

and two small claws. Subsequent molts witnessed the appearance

of paired protuberances corresponding exactly to the paired plan-

tule on the underside of normal tarsal regions. Amputation

experiments on fifty specimens, involving removal of either or both

antennz at the level of the joint between the first and second, or

the second and third antennal segments, resulted in the production

of twenty cases of regeneration. These regenerations varied to

some extent but all developed the tarsus-like terminations. Ampu-

tations made on young nymphs showed that regenerations developed

more and more with each succeeding molt and the resemblance be-

tween the regenerated portion and the true tarsal region became

greater. Under certain conditions of the experiments a tibia-like

segment was also produced at the base of the tarsal region.

- Orientation of Ephemerida—Krecker (715, Biol. Bull., 29 :381-

388) finds that the positive reaction of May-flies to air currents

,

68 NOTES, REVIEWS, ETC.

is evidently due to strains exerted on the muscles of those append-

ages which serve the function of attachment, rather than to sensa-

tions resulting from contact of moving air with the body. The

normal resting position on vertical supports which is usually nega-

tive with respect to the earth’s surface, is not, apparently, a pure

reaction to gravity but is entirely or in part accounted for by the

unstable character of the insect’s attachment when in any other

position. May-flies react negatively to bright sunlight but posi-

tively to certain artificial lights. An optimum zone surrounds

colorless, sixteen candle-power, incandescent lights, beginning about

six inches from each light and extending to about thirty inches, in

which the positive reaction seems to be satisfied. Individuals

alighting in this zone tend, if large numbers are present, to arrange

themselves in rows corresponding to the radii. The area within

six inches of the light is designated as the “excitement zone” since

individuals entering this zone become excited and perform confused

movements. The positive reaction is much stronger for slightly

yellowish light than for red or blue. Red and blue lights produce

the above-described alignment but a well-defined excitement zone is

lacking.

Population of “Blanket-Alge.”’—Platt (’15, Am. Nat., 49:752-

762), in a study of the life of floating masses of filamentous alge

(“blanket-alge”) in fresh-water pools near Ithaca, N. Y., finds

that insects are prominent components of such a community. The

larve, nymphs, and adults of five orders of insects are regular

inhabitants of the alga-masses and constitute the largest individuals

of the population. Nymphs of Ephemerida (Callibetes, Betis, et

al), nymphs of Odonata (Enallagma, Ischnura, et al), larve of

Diptera (Chironomus, Ceratopogon, Odontomyia), larve of Coleop-

tera (Hydroporus, et al), and adult beetles (Helophorus, Creno-

philus, et al) were found to constitute the principal insect popula-

tion, the Diptera representing the greater part. Chironomus was

one of the two animal forms which appeared most regularly. Mem-

bers of this genus were present at all seasons. The larve of May-

flies and midges are the principal plant consumers and since the

AMERICAN MICROSCOPICAL SOCIETY 69

latter are so prolific they are of great importance as food for other

animals. Important data concerning the plant and other animal

members of this population are given.

Lepidopterous Larve.—Fracker (’15, Illinois Biological Mono-

graphs, 2:1-169), in an extensive paper on the classification of lepi-

dopterous larve, reports, among others, the following general re-

sults: The primary sete, which constitute important taxonomic

characters, have an arrangement in all segments of the body of the

larva which has been derived from the same ancestral type, the

latter including twelve primary sete which are arbitrarily desig-

nated by Greek letters. Modification of this type has come about

in three different and independent ways, namely, tendency of pro-

thorax to retain the maximum number of sete, partial reduction on

the meso-and metathorax, and reduction of abdominal chetotaxy

without much change of positions. Other general conclusions of a

more special nature are also given. Extensive keys to families,

genera and species are presented, accompanied by detailed discus-

sion. This paper covers the whole order Lepidoptera and is the

most comprehensive and thoroughgoing treatment of the subject

which has yet appeared.

Poisons of Plant-Lice—Dewitz (’15, Ann. Ent. Soc. Am.,

8 :343-346) reports that the diluted extract of certain plant-lice

obtained by triturating these animals in physiological salt solution

or a mixture of glycerine and physiological salt solution, when sub-

mitted to ox blood, hzemolyzes the red blood-corpuscles even at

ordinary temperatures. “1 gr. of plant-louse matter will completely

dissolve the red blood-corpuscles of 25 ccm. of undiluted blood or

40 gr. will dissolve a litre of blood.” The substance causing this

hemolysis is given the name aphidolysin. Nothing is known con-

cerning the particular part of the body of the insect which contains

this poison.

Stimulh and Egg Hatching.—Severin, Severin, and Hartung

(715, Psyche, 22:132-137) have carried on experiments to determine

the stimuli which cause the eggs of Chetogedia monticola, a leaf-

ovipositing tachinid (Diptera), to hatch. These eggs are deposited

on various grasses and weeds and, at the time of oviposition, con-

tain fully developed larve. Since the larva is a parasite in certain

,

70 NOTES, REVIEWS, ETC.

other insects which consume the vegetation on which these eggs

occur, what. accounts for the sudden hatching in the digestive tract

of the host which permits the parasite to begin penetrating the wall

before being expelled with the excreta? Eggs, placed in the alkaline

liquids exuded from the mouths of certain host caterpillars, began

hatching within less than one minute, almost all of them hatching

within three hours. Similar results were obtained using alkaline

liquids from insects which are not the normal hosts. Hatching

occurred, in most cases, in the mid-intestine. Emergence was

partially prevented, sometimes completely so, in various acid media.

Experiments seemed to show that increased turgidity causes the

larve to emerge when the eggs were immersed in water or diluted

alkaline solutions for thirty-six hours or longer. Evidence was

secured which points to the probability that the digestive juices

of the host, reaching the larva through the micropyle, stimulate

it to perform the body movements and contractions by which the

escape from the chorion is affected.

Polyembryonic Development.—Patterson (715, Biol. Bull,

29 :333-372) finds that in Copidosoma gelechie, a hymenopterous

parasite of the Solidago gall-moth (Gnorimoschema gallesolida-

gonis), polyembryonic development occurs, the egg giving rise, on

the average, to about 191 individuals. The cleavage stages were

not secured, the earliest development studied being that in which

the division of the egg into embryonic primordia had begun. The

young polygerms have an outer nucleated membrane and a central

region containing the true embryonic nuclei. The latter, by segre-

gation into groups surrounded by a dense layer of granular proto-

plasm, develop into the primordia of the multiple embryos. The

polygerm elongates, breaks up into several spherical primary masses,

each of which contains several primitive embryos. Primary masses

give rise to secondary masses and the embryos separate from each

other, each developing a covering composed in part of granular pro-

toplasm and in part of protoplasm from the nucleated membrane.

The intervening space becomes filled with an inter-embryonal sub-

stance, the subsequent dissociation of which liberates the larve,

thus introducing them into the body-cavity of the host where

they ultimately destroy the unchitinized parts of the caterpillar.

AMERICAN MICROSCOPICAL SOCIETY 71

The emergence of males and females from the same caterpillar is

interpreted as the result of the deposition of two or more eggs

in the same host. However, the possibility “that such broods

may also arise from a single fertilized egg by a process of dis-

junction of the sex chromosomes during the early cleavage stages”

is suggested.

Gynandromorph Bees.——Morgan (’16, Am. Nat., 50:37-45), in

a paper on the Eugster gynandromorph bees, reviews the evidence

pertaining to the two chief theories as to the origin of these anom-

alous insects. Recent studies by Boveri and Mehling on the orig-

inal Eugster gynandromorphs show that the male parts of these

bees are maternal while the female parts are paternal, thus sup-

porting the original hypothesis of Boveri that these anomalous

insects are produced by a delayed fertilization or by some irregu-

larity in the penetration of the sperm into the egg, resulting in the

fusion of the sperm nucleus with one of the two nuclei produced

by the division of the egg, with the ultimate production of an indi-

vidual which posses the characters of the male on one side and

those of the female on the other. Morgan’s theory of gynandro-

morph origin is based on the possible entrance of two or more

spermatozoa into the egg with a subsequent union of one with the

egg nucleus and the independent development of an outlying sperm-

atozoan, the former producing female structures and the latter

producing male structures. According to the theory of Boveri,

the male parts resulting from the single egg nucleus should be

maternal while by Morgan’s theory the male parts derived from the

single sperm nucleus should be paternal. Attention is called to the

discovery by Newell that the drone bees inherit the characters of

the mother. It thus appears that Boveri’s theory holds, at least

for the case of the honey-bee. Boveri’s cytological argument in

support of his theory is reviewed but it is found by Morgan to

be of uncertain support. Mention is made of a third possible

origin for gynandromorphs, namely, “dislocation during ontogeny

of the two sex chromosomes.” Gynandromorphs would be expected

to arise in insects when conditions would prevail in which certain

nuclei come to contain two sex chromosomes and others only one.

Attention is also called to Goldschmidt’s explanation of the gynan-

,

72 NOTES, REVIEWS, ETC.

dromorphs which he secures in crosses of Lymantria dispar and L.

japonica, an explanation which “involves the relative potencies of

the sex factors in the different races.”

Marine Insects—Arndt (’15, Proc. Indiana Acad. Sci., 1914,

pp. 323-336) presents a paper on the habits of the insects and

spiders of the “between tides zone” at Cold Spring Harbor, Long

Island. Particular attention is given to Megamelus marginatus,

Grammonata trivittata, Cluboma sp., Bembidium constructum, Het-

erocerus undatus, Bdelide sp. (?), and Lycosa communis. The

first three are characteristic of the Spartina grass area, while the

last four are common in the outer Juncus area. Almost all

insects inhabiting the zone between high and low tide present

peculiar protective features, some of which are as follows: (1)

Certain unique instincts serve to prevent them from being washed

away by the tide, as for example, the tenacious clinging to the

blades of grass by those insects which inhabit the Spartina zone,

the habit of crawling under the gravel, and the wandering about

for food only during sunny days at low tide. (2) The instinct

of certain forms to swim to the Fucus thallus during the disturb-

ance of high tide, an instinct which is interpreted as one resulting

in protection from aquatic enemies. (3) Marked resistivity of

tide zone species to drowning. (4) Structural modifications which

facilitate locomotion, enabling the possessors to inhabit an environ-

ment in which safety may be dependent upon retreat. Attention

is called to the necessity of tide zone insects being air breathers

since the terrestrial conditions prevail for one-half of the time.

During periods of high tide or submergence they are inactive.

“The most striking phenomena is the strictly zonal distribution of

the insects of the between tides zone.”

Salts Required by Insects—Loeb (’15, Journ. Biol. Chem.,

23 :431-434) has raised five generations of the banana fly, each of

normal motility, on the following nutritive mixture: grape sugar,

0.5 gm.; cane sugar, 0.5 gm.; ammonium tartrate, 0.1 gm.; citric

acid, 0.05 gm.; K,HPO,, 0.005 gm.; MgSO,, 0.005 gm.; H,O, 3 ce.

No NaCl or CaC1,, other than that which may appear as impuri-

ties in the chemicals used, was necessary. K and PO, appeared

to be indispensable and SO, and Mg must be present. These ex-

AMERICAN MICROSCOPICAL SOCIETY 73

periments show that as highly organized an animal as this fly can

be reared on a culture medium as simple as that required for cer-

tain micro-organisms. Attention is called to the general assump-

tion that the evolution of the higher animals could have occurred

only after the appearance of green plants since the latter serve

directly or indirectly as food for the former. Although this is

true in general of the present fauna there is the possibility that

“an evolution of animals as highly specialized as insects might

have taken place independently of the existence of green plants.”

Attention is also called to the results of certain other experiments

which indicate that the nitrite and nitrate bacteria are capable of

forming carbohydrates from carbon dioxide, or possibly other

atmospheric carbon compounds, independently of light, and other

micro-organisms might have the same power. Such micro-

organisms might furnish the carbohydrates necessary for develop-

ment of other micro-organisms requiring sugars for their growth.

It thus seems obvious that the evolution of animals as complex as

the banana fly might have been possible without the existence of

chlorophyll.

Inheritance of Pink Coloration—Hancock (’16, Ent. News,

27 :70-82) has made a study of inheritance of the coloration in

the unusual pink form of the katy-did, Amblycorypha oblongifolia.

He has found that this pink katy-did crosses freely with the nor-

mal green form. When a pink female was crossed with a normal

green male, some of the hybrid F, progeny emerged from the egg

after two years while the rest of the eggs hatched after a period

of three years. Nine of the hybrids had pink coloration like the

mother, and four were green like the male parent. The sexes

were about evenly divided in both the pink and the green forms.

These hybrid F, types have been inbred but the F, generation has

not yet emerged. The pink and green color which appeared after

the first molt was not materially affected by subsequent ecdyses.

The pink and the green colors are hereditary and are regarded

as germinal in origin. The theory that the color is the result of

absorption of coloring matter accompanying the food is rejected.

Pau. S. WEtcH.

Kansas State Agricultural College.

PROCEEDINGS

of the American Microscopical Society

MINUTES OF THE COLUMBUS MEETING

The thirty-fifth annual meeting of the American Microscopical Society

was held in connection with the A. A. A. S. at Columbus, Ohio, Dec. 29,

1915.

In the absence of President Kofoid, Professor Henry B. Ward acted

as chairman. The meeting was called to order at 5 P. M.

The report of the Custodian was read and referred to an auditing

committee, consisting of Dr. H. J. Van Cleave and Professor Frank Smith,

both of Urbana, III.

On motion of Past-president Bleile the Secretary was instructed ‘to

send the greetings of the Society to Mr. Pflaum and to express to him our

regret that he was unable to be present.

The Treasurer’s report was read and accepted, being referred to the

auditing committee named above.

The term of Treasurer Hankinson expired at this meeting, and the

Society acquiesced with regret in his decision not to accept the office for

another term. Unanimously the members present voiced their appreciation

of his faithful and effective service of the Society during six years of its

history, including the difficult period of reorganization.

The following officers were duly nominated and elected: President,

Professor Michael F. Guyer, University of Wisconsin; First Vice-President,

Professor T. L. Hankinson, Eastern Illinois Normal School; Second Vice-

President, Professor L. E. Griffin, University of Pittsburg; Treasurer, Dr.

Harley T. Van Cleave, University of Illinois. Dr. George R. LaRue, Univer-

sity of Michigan, Professor H. S. Brode, Whitman College, and Professor

W. M. Rankin, Princeton University, were elected members of the Executive

Committee.

The Secretary was selected as a member of the Council of the American

Association for the Advancement of Science and was authorized to name

as the second representative for 1916 some member actually in attendance at

that meeting.

On the recommendation of the Executive Committee it was voted to

allow the Secretary $50.00, or such part thereof as may be necessary, in defray-

ing the expense of attending the annual meetings of the Society.

The Chairman and Secretary were empowered to approve the minutes

and prepare them for publication.

The Society adjourned.

T. W. Gatitoway, Secretary.

MINUTES 75

SPENCER-TOLLES FUND

Custodian’s Report for the year 1915

Reported at Philadelphia Meeting...... ‘Ee Se $4184.65

Dividends received ........... Peter ne ae $ 254.67

Life membership No. 6, Seth Bunker Capp..............5-- 50.00 304.67

ND aie eyc sks 4 <atag ta sindie cesses 52 44uy see $4489.32

Wet increase during the year..............25+00uaiee $ 304.67

GRAND TOTAL

ETE MI EIEMEIIER CE OAEC S ce.c sc cig.cnc't sa cedeseebensacecansay $ 800.27

DSP OL NVOCECCINGS |. cass cacacccvecdcnctssesovececcde 758.38

RPPMEHRELBET SHINS . 5 o's s/c s.s unre sid doc a eanAep nacweea ans a 300.00

esbanterest and dividends 5... ecsecaccconsccopecacsanacns 2820.67 $4679.32

LESS

Penman ter Mate tie NS) SN ee Be roe (eee es | $ 150.00

mineues on life memberships... 66c.65 sks cece sc ceccaes 40.00 190.00

Sate Ev MEO dS eS OO ae ae $4489.32

Life Members: (Robert Brown, dec’d.); J. Stanford Brown; Seth

Bunker Capp; Henry B. Duncanson; A. H. Elliott; John Hately.

Contributors of $50 and over: John Aspinwall; Iron City Microscopi-

cal Society; Magnus Pflaum; Troy Scientific Society.

Macnus Prraum, Custodian.

Columbus, Ohio, Dec. 29, 1915.

We, the undersigned committee hereby certify that we have carefully

examined the foregoing account of Magnus Pflaum, Custodian, and found the

same correct.

H. J. Van Creave,

FRANK SMITH,

' Auditing Committee.

76 MINUTES

ANNUAL REPORT OF THE TREASURER OF THE AMERICAN

MICROSCOPICAL SOCIETY

December 24, 1914, to December 24, 1915

RECEIPTS

Balance onvhand from -1914.)5...465: 8032.24 UG EG WO, Oe i aoa $ 243.61

Dies ot old members, 6650 663 CR eee Coe Gara eae 442.87

DUES OE NEW. MEMBERS 1.5.5.) aricechatereistade’ ohewraicl ether et tea et ana ee oe 70.00

PRUUEAEIE TES Poe a lacie reiaatdbelofaloe ch icine s SEER ORR AE tne Oe ae 102.00

Subscriptions. for volume 33.01.) visete've Soee cos aha Oy ee 100.00

insertions for volume sd. il. 4 wuk otor ce cond ao Uae 34.40

SAUSCHIMMOS MOL WONG: 99), is snl d cine Geman Choe aetna hsee 26.00

Subscriptions tor other volumes. |... ele ewer eet ee 103.00

Sales! Ot TPANSACHONS 2) .cctcm tek baes & cee ake Cee cere ae 3.30

From Y. H. Tsou, as part expense of publishing his paper........... 75.00

From H. E. Metcalf, as part expense of publishing his paper........ 25.00

cite membership ofS. BiCappy .. 0s 2.cce vse ce sai be em eee 50.00

Advertisers’ in volume ($3.0. ..2. 2. cceee bee coed he eee ieee 131.25

PAA VETEISOLS( 181 EV ONUINE G4 ir inc lota oto le nse be bee hoe E Ran Cee eee 18.50

PUErHSETS: TH VOIGEIE Ok bacisicic sc vores be Ma ROE ES Bis DLS eee 7.50

madvertisers voter VOlUIMES.\ s\:ccec eset cece ces roel ee eee eRe 90.00

BBaGeals iS acorns «na atc fy teasis lois (sip eset fe ole witvoigs Riel Sieg rn ae aa ae $1,522.43

EXPENDITURES

Prmuag:. ransactions,, voltimie, 33; 010, 4s: si nce as ooenie be eee $ 198.29

Padugsg: Trassactions, volume 34; tho. A12.°3..5) oc. cd neodaee saneen 483.65

Pintes: tor “Dransactions. vormie 36, 110:..4¢ os oa <icc's sisiih sen aa cmon 6.25

ielatese tor ol ransactions, vole’ 34.) 11O:sode. vO series ate cidetereasa einer 37.70

Platesproriyolumies4 ino. Asia kG cee eos cos clecc odie cinne cebeeioe 24.22

Postage and express for Secretary ............c02000: S21 tek ee 41.61

Postace AvGheRMECKS LEGE PE PEASUTED (5 654 6 cbs s cae ies Pe RU manide Dials 18.50

Office expenses, stationery, stenography, etc........ceeceeccececececs 126.40

Omee- expemsessor the Dneasuter... 0 282s5 bled ecade cele cs atueleiheaten ae 9.10

Advertssme ‘literature, \).) kis wesc we teed od cdd len miedlneale atetathenimen 39.88

Spencer-Tolles!fend*from-S.B. Capp’s Guess .\0.is.ehie ana viegs ates e ee aes 50.00

Sundry | teeth | a eG bos bad ve pkiga Ulin ee eile eels eminem 10.18

Balance jon shan: <yt¢2iisis feiet 85 sic 8 dsc Baca ea ecistdestarelehetenare tative eteiate ental 476.65

Total credits) cio ots eeds ach oe cane sauce cote ee ees aoe ee $1,522.43

‘T. L. HanxKInson, Treasurer.

Signed by Auditing Committee,

We hereby certify that we have examined this account, have checked

items against vouchers on file, and have verified the totals. We find the

report as given above to be correct. H. J. VAN CLEAVE,

FraANK SMITH,

Auditing Committee.

TRANSACTIONS

OF THE

American Microscopical

Society -

ORGANIZED 1878 INCORPORATED 1891

PUBLISHED QUARTERLY

BY THE SOCIETY

EDITED BY THE SECRETARY

VOLUME XXXV

NuMBER Two

Entered as Second-class Matter December 12, 1910, at the Post-office at Decatur,

Illinois, under act of March 3, 1879.

Decatur, ILL.

Review PrintTING & STATIONERY Co.

1916

OFFICERS

Memmcmrepr ey “NE. Hs GITVERS., ails caine sins ajate MEWS ee x O96 dol va arlene Madison, Wis.

First Vice President: T. L. HANKINSON.......ccccccecsseces Charleston, IIl.

wecond Vice President: L. Ev GRIPFIN cccccdececccscncensss Pittsburg, Pa.

ene De Wc RAL TONOAS oral cicic's cGeia wid eisaicielmin ale ale a urninie ack waale Beloit, Wis.

ern ner i> FA, MAN COLEAVE. 4 vcticia'y wna epee tie sie be W tim mieelaia sapien Urbana, IIl.

ReInitis: MAGNUS PRLAUBM, vic occ S cee oes caw dewcews demas Meadville, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE

ePIC IC) FUANCUIES ¢ cisidta tc pelt co ohaid vies a Wad dvlas send dalontesiel Ann Arbor, Mich.

EOD IG St to, cide ue Gaia wi niemale ane mee ale Metaten o ara Walla Walla, Wash.

EX-OFFICIO MEMBERS OF THE EXECUTIVE COMMITTEE

Past Presidents Still Retaining Membership in Society

R. H. Warp, M.D., F.R.M.S., of Troy, N. Y.,

at Indianapolis, Ind., 1878, and at Buffalo, N. Y., 1879

Apert McCatra, Ph.D., of Chicago, Ill.

at Chicago, IIl., 1883

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

at Detroit, Mich., 1890

Simon Henry Gace, B.S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895 and 1906

A. Cuirrorp Mercer, M.D., F.R.M.S., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896

A. M. Briere, M.D., of Columbus, Ohio,

at New York City, 1900

C. H. E1cENMANN, Ph.D., of Bloomington, Ind.,

at Denver, Colo., 1901

E. A. Birct, LL.D., of Madison, Wis.

at Winona Lake, Ind., 1903

Henry B. Warp, A.M., Ph.D., of Urbana, IIl.,

at Sandusky, Ohio, 1905

HeErBert Oszorn, M.S., of Columbus, Ohio,

at Minneapolis, Minn., 1910

A. E. Hertzier, M.D., of Kansas City, Mo.,

at Washington, D. C., 1911

F, D. Hearn, Ph.D., of Philadelphia, Pa.,

at Cleveland, Ohio, 1912

CHARLES Brookover, Pu. D., of Little Rock, Ark.,

at Philadelphia, Pa., 1914

Cuares A. Koro, Ph.D., of Berkeley, Calif.,

at Columbus, Ohio, 1915

The Society does not hold itself responsible for the opinions expressed

by members in its published Transactions unless endorsed by special vote.

,

TABLE OF CONTENTS

FOR VOLUME XXXV, Number 2, April, 1916

Grants from the Spencer-Tolles Fund, by T. W. Galloway..............

Snow-field and Glacier Oligocheta from Mt. Rainier, Washington, with

Plates: XIV-X VIL! by Paul S.Weleheiie tic. csceecee rede eee

On the So-called Intestinal Glands in Necturus Maculatus, by H. T.

Mead) oo ese ee Rigo so ene Ce Oe OO Ree Eee

Filicollis Botulus N. Sp., with Notes on the Characteristics of the

Genus, with Plate’ X VII, ‘by H. J. Van'Cleave.)... ..2-oceeene eee

Notes and Reviews: Notes on Handling Protozoa in Pure Line work,

by R. T. Hance; Embedding in Paraffin, R. T. Hance; A New

Species of Opercularia, with Plate XIX, by N. M. Grier; A Method

of Making Toto Mounts of Unicellular Forms, by R. C. Nesbit;

Method to Clean Used Microscopic Slides, by J. T. Illick; En-

tomological Notes, by P. S. Welch; Notes on Oligochetes, P. S.

Welch; Notes on the Collection and Rearing of Volvox, by G R.

La Rue; A New Embedding Stage, G. R. LaRue; Making Glass

Plates for Covering Museum Jars, G. R. LaRue; Note on Nature

of Cyto-plastid, with Plate XX, E. W. Roberts; Possible Nature of

the “Book Lungs” in Spiders, with Plate XXIi, by E. W. Roberts;

Senescence and Rejuvenescence (Child); Text Book of Histology

(Jordan) ; Medical and Veterinary Entomology (Herms) ; Classifica-

ton ot deepidopteronsluatvce (bracken), a> eedeeeen a cteeaeiete reer

(This Number was issued on May 25, 1916.)

85

125

13

TRANSACTIONS

OF

American Microscopical Society

(Publishedfin Quarterly Installments)

Vol. XXXV APRIL, 1916 No2

GRANTS FROM THE SPENCER-TOLLES FUND

By T. W. Gattoway, Secretary

The Spencer-Tolles fund is an endowment to encourage research.

It has been accumulated by the American Microscopical Society

thru a period of thirty-two years by means of Life Memberships,

by gifts of individuals and societies, by sale of Transactions, and

by accumulated interest. It is intended as a memorial to C. A. and

H. R. Spencer and,R. 3..Tolles, pioneer workers in America in

optical instruments. It has been the desire to have this memorial

a permanently active one,—contintially stimulating scientific work

and lending to scientific progress in the field so long served by the

American Microscopical Society.

The funds are favorably invested and will soon amount to

$5000. Until that sum is reached it is the purpose of the committee

to award less than the annual income each year. In the course of

two or three years it is the hope that the annual grants may total

$250 or $300.

Members of the American Microscopical Society are invited to

aid the Society in reaching the ends for which the fund was estab-

lished. In aiding the Committee find the very best avenues for the

awarding of the grants, members will benefit themselves and the

membership at large, since the results of the researches will be

published in the Transactions. It is the confident expectation that

the Spencer-Tolles Fund will not only advance research, but greatly

strengthen the American Microscopical Society during the years

to come.

The terms regulating the making of grants from the income

of the fund, quoted from the announcement of the Committee, are

given herewith.

82 T. W. GALLOWAY

Regulations Governing Grants from the Spencer-Tolles Fund.

1. The Committee will receive formal application for grants

from the Spencer-Tolles Fund at present only from members of the

American Microscopical Society.

2. For the present, under ordinary circumstances not more

than $100 will be voted in any one year to research purposes. No

money can be granted for any other purpose from the income of

this Fund.

3. Applications for grants shall be filed with the chairman of

the committee.

4. On completion of the work each recipient of a grant shall

give a report of the use to which the grant allowed has been put,

preferably in the form of a paper ready for publication and embody-

ing the results of the work in connection with which the grant

was used.

5. Every grant is made upon the express condition that all

results obtained by its aid shall be offered to the American Micro-

scopical Society for publication in advance of their announcement

elsewhere. Wherever published, the publications including the

results of this work shall contain the distinct statement that the

work contained in the paper was done with the aid of a grant from

the Spencer-Tolles Fund of the American Microscopical Society.

6. The expenditure of the money shall be entirely in the

control of the person receiving the grant and he shall not be

asked to secure or furnish any vouchers covering the expenditure

in detail. On completion of the work he shall file with his report

a statement that such a sum, mentioning the amount, has been

expended and the results of the work are contained in the accom-

panying report. Any unexpended balance retained by the custodian

in making the final payment, or if paid out of the grant not covered

by this statement, shall be returned to him and shall be again placed

in the Fund.

(Signed) Henry B. Warp, Chairman,

SE ae,

Macnus PFLaum,

H. R. Howtanp,

A. M. BLEILE.

THE SPENCER-TOLLES FUND 83

The Committee or the Secretary will welcome correspondence

from members regarding research work which for its preparation

or publication needs the assistance of this fund. It is the purpose

to interpret the conditions with the utmost generosity in the interest

of scientific discovery. It is not the desire to hamper the investiga-

tor by limiting the use of grants to very precise purposes or control

narrowly their expenditure. The fullest possible freedom for the

exercise of individual judgment will be allowed the grantee.

fe Bid One

4

SNOW-FIELD AND GLACIER OLIGOCHATA FROM

MT. RAINIER, WASHINGTON*

By Paut S. WELcH

The material which forms the basis of this paper was collected

on the snow-fields and glaciers of Mt. Rainier, Washington, during

February, March, April, and June, 1915. Specimens first came to

the writer through the courtesy of Professor Frank Smith, of the

University of Illinois, to whom they had been sent by the United

States Bureau of Biological Survey. The collections were made by

Mr. J. B. Flett of the Longmire Ranger Station who later supplied

the writer with six collections from the same region. The writer

wishes to express his indebtedness to Mr. Flett for his continued

interest and his many courtesies in furnishing carefully preserved

material and in supplying data on the habits and appearance of the

living worms.

Genus Mesenchytreus

Both of the species discussed in this paper belong to the genus

Mesenchytreus (Enchytreide), which, at the present time, includes

almost sixty species and varieties, a few of which are of uncertain

standing. Of this assemblage, twenty species and two varieties

are recorded from North America. They are as follows, the type

locality for each being given: beringensis Eisen (Bering Island,

Bering Strait, Alaska), bewmeri Mchlsn. (?) (Hamburg, Germany),

eastwoodi Eisen (Hoods Peak, Sonoma Co., Calif.), fontinalis Eisen

(Pine Ridge, Fresno Co., Calif.), fontinalis var. gracilis Eisen

(Fresno Co., Calif.), franciscanus Eisen (San Francisco, Calif.),

fuscus Eisen (Pit River, Calif.; No. Calif.), fuscus var. inermis

Eisen (West Fork of Feather River and Goose Lake, Modoc Co.,

Calif.), grandis Eisen [Alaska (Sitka? or Juneau?)], harrimani

Eisen (Kadiak, Orca, Metlakatla, Sitka, Yakutat, Unalaska, Alaska;

Lowe Inlet, British Columbia), kincaidi Eisen (Ice-House Lake,

St. Paul Island, Bering Sea, Alaska), maculatus Eisen (Popof

= BAe from the Entomological Laboratory, Kansas State Agricultural College,

o. 18.

,

86 PAUL S. WELCH

Island, Alaska), nanus Eisen (Popof Island, Alaska), niveus Moore

(Mt. St. Elias, Alaska), obscurus Eisen (St. Paul Island, Pribilof

Group; Popof Island, Alaska), orce Eisen (Orca, Alaska), pedatus

Eisen (Goose Lake, Alturas, Modoc Co., Calif.), penicillus Eisen

(Port Clarence, Alaska), setchelli Eisen (Unalaska Island, Alaska),

solifugus Emery (Muir Glacier; La Perouse Glacier, Alaska),

unalaske Eisen (Unalaska, Alaska), and vege Eisen (Port

Clarence, Alaska). ;

All but one of the above-mentioned species were originally

described from North America and are not yet known to occur

elsewhere. Mes. beumeri Mchlsn., a European species, has been

doubtfully reported by Moore (’99, p. 141) from the vicinity of

Philadelphia, Pa. He also reported an undescribed species of this

genus from the same locality. The last American contribution to

the knowledge of Mesenchytreus is that of Eisen (’05) in which

most of the above-listed species are described. However, since

that time new representatives of the genus have been reported from

other parts of the world.

Mesenchytreus gelidus n. sp.*

(Plates XIV-XVI; Figs. 1-19)

Definition.—Length of alcoholic specimens, 21-32 mm., average

about 24.7 mm. Diameter, 1.25 mm. Somites, 66-77. Color, dark

reddish brown to almost black. Prostomium blunt, rounded,

smooth. Head pore at tip of prostomium. Setz sigmoid; all of

same size and approximately uniform in length; in anterior part

of body, 4-5 in lateral bundles, and 7-9 in ventral bundles; in

posterior part of body, 3-4 in lateral bundles and 4-6 in ventral

bundles. Clitellum on 34XI-XIII, continuous around body. Two

septal glands on IV/V and V/VI. Brain with width two to two

and one-third times the length; anterior margin deeply emarginate,

posterior margin almost straight, lateral margins diverging cephalad.

Dorsal blood-vessel arises in XIV ; cardiac body present. Nephridia

with small, slender anteseptal part and large, irregular, com-

pressed postseptal part; efferent duct arises from ventral surface

*A typographical error which the writer was unable to correct appears in the

abstract of this pape: (Welch, 716, p. 143). The name of this species appears therein as

gelicus instead of gelidus.

SNOW-FIELD AND GLACIER OLIGOCH ATA 87

of latter about mid-way of its length. Spermiducal funnel large,

somewhat cylindrical, bent ; length three to four times the diameter ;

collar present, variable, usually reflected or flaring, set off from

body of funnel by distinct,-broad constriction. Sperm duct 6-7

times length of funnel. Penial bulb large, somewhat globular ;

atrium globular but smaller than body of bulb; about twelve,

elongate, finger-like, multicellular glands opening into ental ex-

tremity of atrium about entrance of sperm duct; two sets of glands

within penial bulb. Sperm sacs extend caudad to XXXI-XXXV.

Ovisac single, tubular, bifurcates in XVI; extends to XXXI-

XXXV; contains sperm sacs. One pair of unusually developed

spermathece; ectal opening laterad at IV/V, two inconspicuous

groups of unicellular glands, surrounded externally by definite,

light yellowish area; duct short, cylindrical, symmetrical, straight ;

two well-developed diverticula at ental end of duct, oppositely

placed, elongate, slightly expanded at extremities; ampulla very

long, usually terminating in IX-XI; devoid of connection with

digestive tract; irregular, more or less unsymmetrical, constricted

in regions corresponding to position of septa, caudal end usually

dilated.

This description is based on twenty-seven sexually mature

specimens. Many others of uncertain sexual maturity were ex-

amined in the study of external characters. The type and most

of the paratypes are in the collection of the writer. Paratypes

have also been deposited in the collection of the United States

National Museum and in the collection of Professor Frank Smith.

The habitat of this species will be described in some detail in

another part of the paper.

Affinities—The determination of the affinities of this enchy-

treid is a matter of considerable difficulty, especially when the

foreign species are considered. Many of the latter, recorded a

number of years ago, are not described in sufficient detail to make

possible a profitable attempt to discover relationships. Further-

more, the assemblage of species assigned to Mesenchytreus in-

cludes a number of poorly described ones, such as Mes. armatus

Lev., Mes. menchi Vejd., and Mes. montanus Bret., the affinities

of which cannot be judged either because of the failure to describe

,

88 PAUL S. WELCH

a number of the essential details of structure or because of the

use of sexually immature specimens. The validity of several

foreign species seems to be questionable but, until they and other

poorly described forms receive more intensive work, little can be

done in the accurate determination of the synonymy. After a

careful scrutiny of the literature dealing with the foreign species,

the writer has not found any of them, as described, to closely

approach Mes. gelidus.

Mes. gelidus belongs to the group of species having two

diverticula on each spermatheca. This single point of agreement

does not necessarily indicate close relationship and it is very

possible that the convenient grouping of species on the basis of the

number of diverticula is somewhat artificial However, Mes.

gelidus belongs to the group in which the spermathece are pro-

longed caudad through several somites and lack connection with

the lumen of the digestive tract. It appears that at least five

American species, namely, Mes. harrimani Eisen, Mes. setchelli

Eisen, Mes. franciscanus Eisen, Mes. obscurus Eisen, and Mes.

maculatus Eisen, are to be regarded as close relatives. They have

been described in considerable detail and fairly satisfactory com-

parisons are possible.

Mes. harrimani differs from Mes. gelidus in having a length

of more than twice the average of the latter; a larger number of

somites; a smaller number of sete in both lateral and ventral sets;

brain square, not markedly wider than long; a longer and more

slender spermiducal funnel; a much shorter sperm duct; and less

compact nephridia, each possessing a distinct bladder-like chamber

near the ectal opening of the efferent duct. Slight differences occur

in the position of the clitellum and in the distribution of pigment.

The penial bulb and associated structures are similar in some re-

spects but a satisfactory comparison is prevented owing to a dis-

crepancy in Eisen’s description (’05, pp. 24-25) in which the following

statement is made: “Atrium medium size, with about sixteen large

gland-fascicles opening at the entrance of the atrium into the bulb.”

In the “Synopsis of species of Mesenchytreeus” in the same paper

(pp. 18-20) the following statement is made: ‘“Penial glands, about

12 long atrial glands”. LEisen’s text figure No. 6 shows nine atrial

SNOW-FIELD AND GLACIER OLIGOCH.ETA 89

glands and another figure (Plate II, Fig. 4) shows fourteen. Both

figures are, however, diagrammatic. No discussion of such varia-

tion occurs in the description and the writer is at a loss to know

what interpretation to put upon the matter. Disregarding the

atrial glands, the structure of the penial bulb, particularly the

internal glands, differs from that of gelidus.

Mes. setchelli differs from Mes. gelidus in possessing a rounded

brain with a decidedly convex posterior margin; in having the origin

of the dorsal blood-vessel in XVIII; in having sperm sacs which

reach only to XVIII; and in possessing only five atrial glands in

connection with the penial bulb. Smaller differences exist in the

character of the spermiducal funnel, nephridia, and in the details

of structure of the penial bulb.

Mes. franciscanus differs from Mes. gelidus in the distinctly

smaller number of sete per bundle in both sets; in the origin of

the dorsal blood-vessel in XVI; in the much longer and more

slender spermathecal diverticula; and in the spermiducal apparatus

which has a single, large, well-defined accessory gland in con-

nection with the penial bulb, a sperm duct not longer than one and

one-half times the length of the funnel, and distinctly sessile, glob-

ular, atrial glands. Minor differences exist in the position of the

clitellum and in the finer structure of the penial bulb.

Mes. obscurus is distinguished from Mes. gelidus by the posi-

tion of the clitellum on XII and XIII; the very long, slender,

spermathecal diverticula; the very slender spermiducal funnel; the

loosely constructed, three-lobed nephridia; and the possession of

16-20 atrial glands in connection with the penial bulb.

Mes. maculatus seems to be a close relative of Mes. gelidus

but differs from it in the number of sete per bundle in the lateral

set; in the deltoid shape of the brain; in the spermathece in which

the slender diverticula are not located at the junction of the duct

with the ampulla and are much shorter than the former; and in

the possession of three sets of internal penial bulb glands, one set

consisting of multicellular glands.

External Characters

The body of Mes. gelidus is elongate, sub-cylindrical, smooth,

and of about uniform diameter, except in the regions cephalad of

,

90 PAUL S. WELCH

the clitellum and near the posterior end where there is a gradual

tapering towards the extremities. In alcoholic specimens, there

is a slight but distinct dorso-ventral flattening accompanied by a

faint, shallow, mid-ventral, longitudinal depression which is present

throughout the greater part of the body. However, since the writer

has not had the opportunity of studying living material, no state-

ment can be made concerning the constancy of these characters and

there is the possibility that they are unnatural results incident to

preservation and that the true form is a cylindrical one as is the

case in many of the Enchytreide. The length, in preserved ma-

terial, varies from 21 to 32 mm., the average of twenty-five sexually

mature specimens being 24.7 mm. The maximum diameter, in

the region of the clitellum, is about 1.25 mm. The segmentation is

distinct in all parts of the body. The intersegmental grooves are

narrow, shallow, and regular in outline, except in the vicinity of

the extremities where they are broader, deeper, and more con-

spicuous, particularly on the cephalic end. The deepening of the

intersegmental grooves in the regions of the extremities produces

an antero-posterior convexity of the surface of intervening somites

which elsewhere is uniformly plane. On the surface of each somite,

midway between the margins, is a faint elevation or ridge which

encircles the body, including the four sete bundles. A number

of the specimens show, in the middle region, a series of ruptures

in the intersegmental grooves, thus producing whitish rings which

consist of interruptions, more or less regular, of the cuticula and

hypodermis, exposing the underlying muscle layers of the body-

wall. Further discussion of these ruptures occurs in another part

of the paper.

The number of somites varies from 66 to 77, the average of

twenty-five specimens being 69. A few mature specimens were

studied in which the number was as low as 50 but these were dis-

regarded since there was some evidence of loss of somites and

subsequent regeneration in the posterior region. The color of most

mature specimens is, in general, deep reddish-brown to almost jet-

black. The distribution of color is not uniform. The ventral sur-

face is often of a slightly lighter hue and the anterior and posterior

regions are invariably lighter in color. In occasional specimens,

SNOW-FIELD AND GLACIER OLIGOCH TA 91

the terminal somites are light yellow. Sometimes the black color

predominates over almost the entire body. A few specimens were

found in which a distinct, rather abrupt transition from also black

to yellow occurred in the vicinity of LX but they are referred to

above as displaying some evidence of regeneration, a possible ex-

planation for the difference in color. The maximum intensity of

the black color occurs dorsad and laterad, in the region behind the

clitellum. An examination of the surface under magnification

shows the universal presence over the body, save on the clitellum,

of innumerable, minute, irregularly distributed, light yellow spots,

which give the surface a flecked appearance. These microscopic

areas are slit-like, the long axes predominantly extending in the

direction of the circumference.

Certain, special, superficial areas show distinct color differ-

ences. The ectal opening of each spermatheca at IV/V is sur-

rounded by a broadly fusiform area which occupies about one-

half the width of the two adjacent somites and is rendered rather

conspicuous by the contrast with the surrounding surface. The

crescent-shaped mouth and the transverse slit-like openings of the

penial bulbs and oviducts are surrounded by narrow but distinct,

light yellow areas. On the ventral surface, beginning with VII,

a pair of small, circular, widely separated, yellow spots occur on

either side of the mid-ventral line and in close proximity to the

cephalic margin of each somite. These are the ectal openings of

the nephridia.

The clitellum occurs on 34XI-XIII. Some slight variation in

extent was noted but on completely mature specimens the above-

mentioned limits hold. It is moderately thick, increasing, to a

limited extent, the diameter of the body in that region. The dis-

tinct, uniform, yellow color renders it a conspicuous external char-

acter. It completely surrounds the body, no diminuation of thick-

ness occurring on the ventral side. The surface is smooth and

lacks the flecked appearance described for other regions of the

body.

The head pore is distinct externally and located on the apex

of the prostomium. The ectal opening has the form of a trans-

,

92 PAUL S. WELCH

verse slit and is surrounded by a narrow, yellowish area. Dorsal

pores are absent.

The sete are distinctly sigmoid and arranged in fan-shaped

bundles which are disposed in four longitudinal rows, two ventral

and two lateral. The sete of a bundle are all of approximately

equal development. In the anterior part of the body, there are 4-5

sete in the lateral bundles and 7-9 sete in the ventral bundles. In

the posterior part, there are 3-4 sete in the lateral bundles and 4-6

in the ventral bundles. The sete on XI are not specialized.

Internal Characters

Lymphocytes.—In the alcoholic specimens examined, the lymph-

ocytes (Pl. XIV, Fig. 4) are scanty in the anterior region of the

body but posterior to the clitellum they occur in some abundance.

They vary in shape to some extent but, in general, are oval or

elliptical. All lymphocytes are so heavily loaded with dark, non-

staining pigment-granules that the cytoplasm is almost entirely

obscured and frequently the nuclei are almost completely hidden.

Chloragog Cells——Aside from the anterior five or six somites,

the digestive tract is covered with chloragog cells (Pl. XIV, Fig. 5)

for the greater part of its length. They are closely set together,

usually elongated, and expanded at the free ends. In most of the

specimens examined, these cells were heavily loaded with numer-

ous, minute pigment-granules. In many instances, the amount of

pigment present was almost sufficient to render the ectal portion of

the cell unstainable.

Brain.—The brain (Pl. XV, Fig. 10) lies almost entirely in I,

although in some of the specimens it extends slightly into II. It is

easily dissected out in toto, thus facilitating the study of the organ

as a whole. In all of the preparations, the shape and proportions

are quite constant. The width is approximately from two to two

and one-third times the length, an average measurement being:

length, 0.132 mm.; width, 0.301 mm.; maximum thickness, about

0.011 mm. The anterior margin is deeply emarginate and slightly

angular in character while the posterior margin is very slightly con-

cave. From the rounded latero-caudal angles, the lateral margins

diverge cephalad. Two pairs of supporting strands extend to the

SNOW-FIELD AND GLACIER OLIGOCH-ETA 93

body-wall, one arising from the anterior part near the emargination

and the other from the posterior margin.

Nephridia.—The nephridia (Pl. XV, Figs. 14, 18) begin on

VI/VII. Their shape varies somewhat in different regions of

the body and in different specimens but, in general, the anteseptal

part is composed of a nephrostome borne on an elongated, narrow

pedicel. The postseptal part is an enlarged, irregular, compressed

mass, the posterior end of which is reflected cephalad and gives

rise to the efferent duct. In the large majority of the specimens

examined, the nephridia are distinctly compressed and lie flat

against the ental surface of the body-wall. Structurally, the body

of the nephridium is of the usual mesenchytreid type. No evi-

dence of a reservoir at the ectal end of the efferent duct was

observed.

Spermiducal Funnel—This organ (Pl. XV, Figs. 15-17) lies

in the usual position in XI. The dimensions show limited varia-

tion but the length is commonly from three to four times the maxi-

mum diameter. A well-developed, variable collar is present. In

all of the specimens examined, the funnels are bent in varying

degrees, and the opening is directed caudad. The sperm duct is

approximately 6-7 times longer than the funnel and extends caudad,

usually to XIII/XIV. It is then reflected cephalad, extending into

XII to unite with the penial bulb.

Sperm Sacs and Ovisac.—A large part of the ccelom posterior

to the clitellum is occupied by the extensive sperm sacs (Pl. XIV,

Figs. 1-2) and the single ovisac. They lie ventrad and laterad of the

alimentary canal and are the most conspicuous of the internal

organs. They are formed by very long caudal extensions of cer-

tain septa in the clitellar region. In the specimens examined, the

delicate nature of these septa and the crowded condition of the

internal organs in the clitellar region make the exact determination

of the origin of the sperm sacs and the ovisac difficult and it is

only by careful reconstructions of serial sections that the beginnings

of these storage sacs can be followed. Septum XII/XIII continues

caudad as a single, tubular outerowth to XVI where it divides into

similar halves, a right and a left, which lie on either side of the

median line. The posterior termination, in the specimens exam-

,

94 PAUL S. WELCH

ined, varies from XX XI to XXXV inclusive. Definite constrictions

occur at intersegmental regions while between the latter distinct

swellings are present. In sexually mature specimens, developing

masses of ova occur in great quantities throughout the entire length

of the sac.

Septum XI/XII continues caudad as two tubular outgrowths,

one corresponding to each spermiducal funnel, which enter the

ovisac and are completely contained within the latter and its

branches. In XVI, where the ovisac divides, each sperm sac enters

the corresponding branch of the ovisac and is coterminal with it,

the variation in the position of the end being XXXI-XXXV. The

sperm sacs also show constrictions and swellings which correspond

to the segmentation. They fill approximately one-half of the lumen

of the ovisac and, in sexually mature specimens, are crowded full

of developing spermatozoa. The opening of each spermiducal

funnel is directed towards, and is in close proximity to, the anterior

opening of its corresponding sperm sac, in some specimens being

partly contained within it. The sperm duct apparently lies entirely

outside of these sacs.

A somewhat similar extensive provision for the storage of

the developing reproductive cells has been reported previously in

a few other species. Eisen (’05, pp. 25, 47, 49) found that in

Mes. harrimani the sperm sacs extend “back some thirty somites”

but made no mention of an ovisac; that in Mes. fuscus the sperm

sacs are very large, “extending as far back as somite XXVII or

further”; and that in Mes. fuscus var. inermis the sperm sacs ex-

tend to XXII and the ovisac to XXVIII. Other species are de-

scribed in which sperm sacs and ovisacs are recorded as “extend-

ing far back” or by some other similar, indefinite statement. Many

descriptions contain no mention of sperm sacs or ovisacs. Until

such described species have been re-examined, it will not be pos-

sible to know whether or not these extensive sacs are peculiar to

the American fauna.

Pemial Bulb.—In general structure, the penial bulbs (PI. XVI,

Fig. 19) conform to the mesenchytrzid type of Eisen. They pre-

sent a noteworthy complexity of structure and agree in a number

of respects with the same organs in certain Pacific Coast species.

SNOW-FIELD AND GLACIER OLIGOCHAETA 95

They are attached to the ventral, ental surfaces of the body-wall in

XII, one on either side of the median line. Each organ occupies

a large part of the ccelom, having a total length, exclusive of the

atrial glands, of about two-thirds the diameter of the body in that

region. The maximum diameter slightly exceeds one-fourth of

the transverse body-dimension. In the specimens studied, it was

easy to dissect out these organs and to study them in toto as well

as in serial sections.

Each organ is composed of two distinctly differentiated re-

gions: (1) the globular atrium, and (2) the slightly elliptical

body of the bulb. Superficially, the sperm duct unites with the

ental apex of the atrium and is uniform in diameter from that

point to the spermiducal funnel. About twelve, well-developed,

finger-like, atrial glands are attached to the apex of the atrium near

the union with the sperm duct. All are similar in shape and

dimensions and extend freely into the cclom. The attachments

of these glands are not distributed uniformly about the apex of

the atrium but are aggregated largely on one side.

The internal structure of the penial bulb is complicated and

presents some interesting detail. In the completely retracted con-

dition, the extension of the sperm duct forms at least one-half

of the length of the bulb as a whole. The remainder of the organ

is that part surrounding the penial bulb invagination. The con-

tinuation of the lumen of the sperm duct widens within the atrium

to form a definite, spacious chamber, corresponding in contour to

the external surface of the globular atrium. This chamber, at its

ectal side, leads into an elongated lumen which expands slightly,

forming another chamber, just entad of the penial pore. This ex-

pansion seems to correspond to the “penial chamber” described by

Eisen (’05, p. 8). The penial bulb invagination is deep, bounded

on the mesal side by a rather smooth wall, but on the opposite side

two strong folds are present. It is lined throughout by a contin-

uation of the external cuticula. The lining epithelium of the atrium

differs from the corresponding tissue in the sperm duct in that

the cells are elongated, reduced in transverse dimension, and lack

cilia. The muscle-layer is in close proximity to the bases of these

cells and while it varies somewhat in thickness and is interrupted at

,

96 PAUL S. WELCH

intervals, it can be traced to its origin from the circular muscle-

layer of the body-wall. The epithelium, at the penial pore, grad-

ates into the hypodermis which forms the greater part of the

lining of the penial bulb invagination. Structurally, it differs from

the peripheral hypodermis only in the reduced length of the cells

and the absence of the heavy, ectal zone of pigment, except at the

entrance of the invagination and on the extremity of the first fold.

The lateral portion of the bulb contains a large number of loosely

associated muscle-strands which extend, in general, from the peri-

phery towards the interior. The retractor muscle is formed largely

by the union of strands from the circular muscle-layer of the body-

wall with two other bands, each extending into one of the large

folds which project into the invagination. The mesal side of the

bulb, particularly near its base, also contains a loose meshwork of

muscle-strands. In the ental half of the organ, a circular muscle-

layer is present, exterior to and in contact with the longitudinal

muscle-layer. The former is particularly well developed in the

lateral half of the bulb. It seems probable that this circular layer

is a continuation of the longitudinal muscle-layer of the body-wall.

A very delicate peritoneum separates the muscle-layers from the

ccelom.

Sections show that the atrial glands are composed of two very

definite regions, a peripheral region and a central one. The peri-

pheral region is constructed of large, somewhat cuboidal, distinctly

nucleated, gland cells arranged in a single layer. The central re-

gion is composed of the extensions of the peripheral gland cells

which evidently function as ducts. The gland cells take artificial

stains intensively but the central region seems to have little or no

affinity for them. These extensions of the gland cells composing

the central region penetrate the wall of the atrium; extend beneath

the muscle-layers, separating the latter from the epidermal lining

of the atrial and “penial’ chambers; and open into the penial bulb

invagination on the surface adjacent to the penial pore.

Two sets of glands occur within the penial bulb. Many large

unicellular glands of varying size and shape intermingle with the

strands of the circular muscle-layer in the ental half of the organ.

It has not been possible to follow out the extensions of these cells

SNOW-FIELD AND GLACIER OLIGOCH ETA 97

and determine with what part of the lumen they are related. An-

other set of glands is present in the lateral side of the ectal half

of the organ and are related to the penial bulb invagination. Small

unicellular, fusiform, gland cells occur in the heavy folds of the

wall, in close proximity to the hypodermis. Each gland has a very

fine extension which is related to the hypodermis but the exact

nature of this relation has not been determined. It seems probable

that these prolongations extend to the surface of the cuticula.

Spermathece —Among the prominent internal organs of the

body is a pair of spermathece (Pl. XV, Figs. 7-8, 12-13) which

first appears in V. These organs are greatly elongated, often ex-

tending caudad as far as XI and occupying the large part of the

ccelom in that region. Each organ is composed of three distinctly

differentiated parts, namely, duct, diverticula, and ampulla. The

duct is straight, elongate, cylindrical, and slightly greater in diam-

eter near its middle. The ectal opening is laterad in position in

IV/\V, slit-like, and surrounded on the external surface of the body

by the distinctly light colored area already described. Two groups

of unicellular glands are associated with the ectal opening, one on

the cephalic and the other on the caudal side. The component

glands of each group are elongate, club-shaped, and distinctly nu-

cleated. These groups of glands are apparent only in sections and

because of their small size may be overlooked in a casual exam-

ination. At the junction of the duct with the ampulla are two,

smooth, club-shaped, oppositely situated diverticula, each of which

is slightly longer than the spermathecal duct and is reflected caudad,

parallel with the long axis of the ampulla. The bulk of the sper-

matheca is composed of the greatly elongated ampulla. It is char-

acterized by a series of swellings and constrictions, the latter cor-

responding to the intersegmental grooves, and the whole ampulla

often has a moniliform appearance. There is no connection of any

kind with the digestive tract but the caudal, free extremity of the

organ is an expanded sac, variable in form, and usually larger than

any of the other distended portions of the ampulla.

The spermatheca shows some interesting variations. The duct

and diverticula are comparatively constant in shape and size but

the ampulla is variable. Commonly, the ampullz in the same speci-

,

98 PAUL S. WELCH

men are of equal development and approximately of the same

shape but a number of specimens were examined in which one am-

pulla (Pl. XV, Figs. 12-13) was greatly elongated, extending into

1X, while the corresponding one on the opposite side of the animal

was reduced, extending through only one or two somites, and con-

siderably different in shape. The usual position of the ampulla

is parallel to and latero-ventral of the digestive tract but specimens

were examined in which the ampulla were somewhat contorted

and partially wrapped around the digestive tract. It is possible

that such a condition is responsible for the reduced size of one

ampulla since in certain specimens the ampulla on one side had

apparently exceeded the other in growth, had filled the available

space on its side of the ccelom, and had become crowded to the

opposite side while the ampulla of the opposite spermatheca had

grown caudad until it came into contact with the other one and

had evidently ceased development, resulting in its reduction in

length. An examination of these reduced ampulle in situ some-

times showed the free extremities in contact with the opposite am-

pullz and doubled upon themselves, suggesting a crowding of parts

in development.

The excellent state of preservation of the specimens made pos-

sible a study of the finer structure of the spermatheca. The ex-

ternal cuticula is reflected into the ectal opening and forms a

complete lining for the lumen of the spermathecal duct, disappear-

ing at the bases of the diverticula. The hypodermis merges into

the. lining epithelium of the duct which composes by far the greater

part of the thickness of the wall. The cells are elongated, gland-

ular in appearance, closely set together, and distinctly nucleated at

their bases. They are longer in the middle region of the duct and

are responsible for that position of the maximum diameter of the

organ. Art the ental end of the duct, these cells gradate rather

abruptly into the lining epithelium of the diverticula. The cir-

cular muscle-layer of the body-wall forms the longitudinal muscle-

layer of the duct for its entire length, diminishing in thickness at

the bases of the diverticula. It has not been possible to determine

whether the longitudinal muscle-layer of the body-wall is related

to the spermatheca. Unicellular glands occur over the outer sur-

face of the duct throughout its entire length.

SNOW-FIELD AND GLACIER OLIGOCHA:TA 99

The walls of the diverticula are composed of a lining of epi-

thelium, constructed of cuboidal, closely set, glandular, distinctly

nucleated cells, bounded on their ectal ends by a very thin muscle-

layer which, in turn, is covered by a continuation of the above-

mentioned peritoneum.

Structurally, the ampulla is composed of two regions, a short

ectal portion adjoining the duct, and a very long ental part extend-

ing caudad. The lining epithelium of the ectal region shows numer-

ous transverse folds, thus increasing its surface to a considerable

extent. This epithelium usually has irregularly shaped, small,

non-staining pigment-granules in the free ends of the cells. The

muscle-layer is well developed in this part of the diverticula. Uni-

cellular glands occur exterior to the muscle-layer and are bounded

at their outer ends by the peritoneum. In the remainder of the

ampulla, the wall is greatly reduced in thickness so that the layers

are difficult to distinguish. A thin lining epithelium and a delicate

peritoneum are present and there are some hints of the presence

of a muscle-layer, the exact character of which could not be de-

termined. Small, scattering, irregular thickenings occur on the

inner surface of this region.

The contents of the spermathece present some interesting

features. In all of the sexually mature specimens examined, the

spermathecz contain spermatozoa which have a definite distribution

in the organ. No spermatozoa were found in the duct but the

diverticula almost invariably contained them, each mass having a

definite and constant relation to the epithelial lining. The heads

are all in contact with the lining of the diverticulum and the tails

extend out into the lumen. The meaning of this arrangement is

not clear. Spermatozoa are almost constantly absent from the ectal

portions of the ampulla but, in the long, expanded part, surprising

quantities, crowded into large masses, are present in the lumen and

are not related to the wall in any way.

The striking structural feature of the spermathece is the

unusual size. It appears from a study of the literature on Mesen-

chytreus that greatly enlarged and elongated spermathecze, such

as the type just described, have been found only in American species

from the Pacific Coast. Eisen (’05) described such organs for the

,

100 PAUL S. WELCH

first time in the following species: Mes. harrimani, Mes. setchelh,

Mes. franciscanus, Mes. obscurus, Mes. maculatus, Mes. vege, and

Mes. orce. As descriptions stand at present, it appears that in this

large genus only a small group of species possesses this particular

type of spermatheca. Eisen (’05, p. 15) makes the following state-

ment in this connection: ‘There is some little reason to suspect

that this enlargement of the spermathece in this genus may have

been overlooked in some species, and that some spermathecee which

have been described as short and as immediately connecting with

the intestine, in reality are greatly prolonged posteriorly. The part

adjoining the diverticles is always narrow and closely approaches

the intestine. This peculiarity causes it to tear readily and I am

satisfied that such torn spermathecz have been considered as en-

tire.” Whether Eisen’s speculations are true remains to be proved

but since some of the descriptions of foreign species are very

meager, unsatisfactory, and evidently made without careful dis-

section of specimens or the study of serial sections, it is possible

that this type of spermatheca is not quite as unique as it now seems.

However, since the spermathece have long been used as a taxonomic

character and therefore called for special attention, it would appear

that the number of cases in which such exceptionally large organs

would be overlooked must, at best, be quite small. An inspection of

the above list of species possessing such spermathecze shows that

these forms are all Alaskan in distribution, save Mes. franciscanus.

It might be suspected that greatly enlarged and prolonged sperma-

thecze are characteristic of species inhabiting cold regions but Mes.

falciformis Eisen, Mes. fenestratus (Eisen), Mes. primevus Eisen,

and others are found in the arctic regions of the Old World and

yet do not possess this peculiarity. Likewise, Mes. solifugus Emery

and Mes. niveus Moore, found in frigid conditions in Alaska, have

spermathece of the ordinary enchytreid type.

Pigmentation.—Examination of sections of the various regions

of the body shows that the color described in foregoing pages has

its basis in dark, brownish, non-staining pigment-granules which

occur in marked abundance in the body-wall and certain internal

organs. The hypodermis bears the principal load, the pigment be-

ing distributed through this whole layer. It occurs chiefly in the

SNOW-FIELD AND GLACIER OLIGOCHETA 101

outer ends of the hypodermal cells but may be scattered all through

them. Pigment-granules are present in varying amounts in the

following internal organs: (1) lymphocytes; (2) chloragog cells;

(3) epithelial lining of the ectal, folded end of the spermathecal

ampulla; (4) ectal portion of the hypodermal lining of the penial

invagination; (5) setigerous glands; (6) lining of the buccal cavity

and the pharynx; and (7) ectal ends of the efferent nephridial ducts.

Of the above-mentioned internal structures, the lymphocytes and

the chloragog cells contain the largest amounts of pigment. Gran-

ules do not seem to occur in connection with the nervous systems

as is the case in Mes. solifugus.

BIOLOGICAL NOTES

The only recorded observation of “snow worms” on Mt. Rainier

which the writer has been able to find is given by Moore (99,p.

142): “In a letter Prof. Russell adds the interesting information

that he has observed similar worms on the snows of Mt. Rainier,

Wash., thus indicating for them a wide distribution.”

All of the information concerning the living form has been

supplied by Mr. J. B. Flett, who, as stated before, furnished the

writer with the material on which this paper is based. Sexually

mature specimens were collected from February 23 to April 5.

Whether this represents the seasonal period of sexual maturity is

not known. Between the above-mentioned dates, these worms oc-

curred abundantly on the snow-fields of Mt. Rainier, at an eleva-

tion of from 2700 to 5600 feet. They also occurred on the snow

on the mountain slope in a dense forest of fir and hemlock. These

worms have not thus far been found on ice nor on the graciers

though they occur on the snow below the ice front and outside

of the lateral moraines of Nisqually Glacier. The snow on which

they were found is not permanent through the entire season but

melts with the coming of summer and it therefore appears that

a part of their life history must be spent on or in the ground.

During midwinter when the temperature is very low, they are in-

active and do not appear on the surface of the snow. Appearance

at the surface accompanies the rising temperature in the spring

and their activity becomes noticeable when the snow is beginning

,

102 PAUL S. WELCH

to melt. When placed on hard packed snow during their active

period, they are able to bore down through it at will. Under con-

ditions of softening snow, they exhibit a rather efficient locomotion.

When taken in the hand, they perform lively squirming movements

for a time but soon relax and become quiet. Blue jays and several

other species of birds prey upon these worms, picking them off the

surface of the snow.

There is the possibility that these enchytrzids undergo a color

change during the first few days of their appearance. The first

specimens, which were collected January 7, are very light yellowish

in color and show no evidence, externally or internally, of pigment.

Since these specimens are sexually immature, specific identifica-

tion is not possible but they seem to be the species under discussion.

As already stated, the sexually mature form is very dark in color

and bears a conspicuous amount of pigment. Mr. Flett is of the

opinion that, since the light colored specimens only appear very

early in the season and since dark specimens of similar size appear

later in the same localities and in approximately the same numbers,

this difference in color is probably not a species difference but

rather a life history difference in the development of the same

species. None of the light colored specimens examined by the

writer have been sexually mature but all of the dark colored in-

dividuals have either been completely mature or very close to

complete sexually maturity. The evidence thus far is circumstantial

only and does not justify any definite conclusions. It may be men-

tioned in this connection that Moore (’99, p. 135), quoting Mr.

Bryant, reports what seems to be a similar color change in Mes.

solifugus.

Nothing definite is. known concerning the food of these snow-

worms. Mr. Flett reports that the snow over which these enchy-

treids crawl has a red color, due to a minute, unicellular plant,

which, in his opinion, serves as food for the worms. The writer

made some examinations of the material contained in the

alimentary canal of these worms, and found what seems to be

microscopic alge composed of very minute, globose cells, contain-

ing greenish and reddish colors, occurring singly or in clusters,

and having the appearance of Pleurococcus. This material occurs

SNOW-FIELD AND GLACIER OLIGOCHETA 103

in considerable quantity in the digestive tract and offers evidence

leading to the conclusion that the minute snow alge constitute at

least a part of the food of these worms.

A number of the collections made by Mr. Flett contained rep-

resentatives of the associated animal life. Insects belonging to

seven orders, Collembola, Hemiptera, Plecoptera, Coleoptera, Dip-

tera, Lepidoptera, and Hymenoptera (several species in five of the

orders), one species of Gastropoda, and three species of Araneida

were found in the same habitat with the snow-worms. The Collem-

bola (Isotoma sp.) occur in enormous numbers, especially on the

snow below the glacier, making it black in appearance. In this

respect the situation resembles that described by Moore (’99, p. 136)

for Mes. solifugus which had great quantities of a collembolan,

thought to be Achorutes nivicola, associated with it. All of these

associated animals are black or very dark, except one species of

spider and one species of Hemiptera, both of which are largely

of a dark red color.

Mesenchytreus solifugus rainierensis n. var.

(Plate XVII, Figs. 20-26)

A collection from the upper snow-fields of Mt. Rainier, made

on June 17, 1915, by Mr. Flett, contained seventy-five specimens

of any enchytreid, blackish in color but smaller than Mes.

gelidus. A thorough study of this material, which is in good his-

tological condition, showed that it must be. regarded as Mes.

solifugus Emery. However, several structural characters fail to

correspond to the descriptions of Emery (’98a, ’98b, ’98c, ’00a, ’00b),

Moore (’99), and Eisen (’05). Previously known material of

Mes. solifugus could not be secured for study but a very careful

comparison of the characters of the material from Mt. Rainier with

the published descriptions indicates that the deviations are appar-

ently not sufficient to justify the separation into another species.

Nevertheless, the variations are so constant that the writer feels

convinced that it must be considered as a new variety.

Mes. solifugus was first described by Emery under the name

Melanenchytreus solifugus, from specimens collected by Filippi on

Malaspina Glacier, at the base of Mt. St. Elias, Alaska. The fol-

,

104 PAUL S. WELCH

lowing year, Moore (’99) published a more extended account of

the same species from material collected by Mr. H. C. Bryant, also

on Malaspina Glacier. His paper contained not only the results

of a careful anatomical study and a quoted account from Mr. Bry-

ant of the habitat and the activities of these annelids, but also an

interesting discussion of their relation to the peculiar habitat, with

special reference to temperature and light, and an account of the

possible function of the dense pigmentation. In the same material,

Moore found another form which he described under the name

Mes. niveus. He also rightly placed Melanenchytreus as a syno-

nym of Mesenchytreus. Eisen (’05) published a short account of

Mes. solifugus, specimens of which were collected by Professors

T. Kincaid and W. E. Ritter during the Harriman Alaska Expe-

dition on Muir Glacier and on La Perouse Glacier. It thus appears

that up to the present account Mes. solifugus has been known only

from glaciers in a very limited region of Alaska.

Definition —Length, 12-18 mm., average about 15 mm. Diam-

eter, about 0.52 mm. Somites, 51-60, average 55. Color, very dark

brown to black. Prostomium rounded, smooth, blunt. Head pore

at tip of prostomium. Sete sigmoid, abruptly bent at distal ends;

uniform in size and shape; in anterior fourth of body, 2 sete, rarely

3, per bundle in lateral rows; in remainder of body, 1 seta, rarely

2, in lateral rows; in anterior third of body, 2-4 sete, usually 3,

per bundle in ventral rows; 2 sete per bundle in ventral rows in

remainder of body. Clitellum absent. Brain but very slightly

longer than wide; anterior margin deeply emarginate, posterior

margin shallowly concave, lateral margins approximately parallel.

Origin of dorsal blood-vessel in XIII-XIV; small cardiac body

present. Nephridia with small, slender, anteseptal part and large,

irregular, lobate postseptal part; origin of efferent duct on ventral

surface of latter very near posterior end. Spermiducal funnel

moderate, cylindrical, tapering slightly towards origin of sperm

duct; length about three times the maximum diameter; collar

absent. Sperm duct very long, extending caudad within ovisac to

XX; masses of coils in XIII-XIV; diameter uniform throughout.

Ovisac extending from XII/XIII to XX, bifurcating in XIII or

XIV. One pair of sperm sacs extending from XI/XII to about

SNOW-FIELD AND GLACIER OLIGOCH-ETA 105

XV ; within ovisac. Penial bulb large, subglobular ; well-developed,

fusiform atrium with five atrial glands; numerous groups of mullti-

cellular glands within bulb. Spermathece confined to V; duct

short, cylindrical, numerous unicellular glands externally; ampulla

but little greater in diameter than duct, elongate, tapering slightly

entad and uniting in posterior part of V with lateral aspect of

digestive tract; two opposite, elongated, cylindrical diverticula

reflected caudad.

The description is based on twenty-seven sexually mature speci-

mens. Forty-eight other specimens of uncertain sexual maturity

were examined in the study of external characters. The type and

most of the paratypes are in the collection of the writer. Paratypes

have been deposited in the collection of the United States National

Museum and in the collection of Professor Frank Smith.

The habitat of this species will be described in another part

of the paper.

External Characters

The body is elongate, cylindrical, smooth, and uniform in

dia..-eter except at the extreme anterior and posterior ends where

there is a slight but gradual tapering. The length of the alcoholic

specimens varies from 12 to 18 mm., the average length of twenty-

seven sexually mature specimens being approximately 15 mm. The

diameter varies from 0.47 to 0.63 mm., the average being about

0.52 mm. Except in the extreme anterior region, the external seg-

mentation is indistinct, the surface being smooth and the inter-

segmental grooves difficult to detect. As in Mes. gelidus, external

examination shows the presence of ruptures in some of the inter-

segmental grooves, thus producing whitish rings between somites.

Longitudinal sections show that these ruptures are breaks in the

cuticula and hypodermis and the underlying muscle-layers are thus

exposed, producing the whitish band. Such ruptures are present

in almost every specimen sent to the writer and occur uniformly

in the middle region of the body, the anterior and posterior ends

only being invariably free from them. No information is available

at present concerning the origin of these interruptions. Moore

(99, p. 126) reports a similar feature in some of the specimens

,

106 PAUL S. WELCH

of Mes. solifugus which he examined. He also states that Mr.

Bryant, the collector who secured the material on Malaspina

Glacier, Mt. St. Elias, and furnished data on the living animal,

informed him that these white or yellow bands “‘were present when

the worms were collected”. On a later page (p. 135), Moore

quotes directly from an account by Mr. Bryant, a part of which

is as follows: “Some of the specimens I obtained had also distinct

whitish bands around their bodies.” From this account it might

appear that these light bands occur in the living worms. Whether

it is true of Mes. gelidus and Mes. solifugus var. rainierensis re-

mains to be discovered. It seems unlikely, from an examination

of the available material, that these interruptions are normal.

Longitudinal sections show ragged edges of tissue about these in-

terruptions, a fact which seems to constitute evidence against such

a view. The appearance suggests the killing and preserving opera-

tions as the cause, although none of the specimens showed signs

of extreme contortion or severe treatment.

The external surface of each somite is smooth and free from

ridges, secondary constrictions, or striations of any sort. The

number of somites varies from 51 to 60, the average being about 55.

Except at the extreme anterior and posterior ends, the somites

are of approximately uniform width. The color of the entire body

is very deep brown to black, except for the above-mentioned

whitish bands between somites. To the unaided eye, the specimens

are black but under magnification, using transmitted or reflected

light, they are a deep, rich brown. The distribution of the color

is almost uniform throughout the body. Specimens, cleared and

mounted in toto, show on the surface, except on XI-XIII, in-

numerable, minute, polygonal areas, usually hexagonal, each of

which has a long and short dimension, at right angles to each other,

the former extending in the direction of the circumference of the

body. Each area contains in its center a light, oval spot.

Certain special, external areas are distinctly lighter in color

than the surrounding surface. The tip of the prostomium and

the lateral parts of the groove 0/I are yellow and offer contrast with

the adjacent parts. The ectal opening of the spermatheca in IV/V

is surrounded by an ovate, yellowish area which, however, is not as

SNOW-FIELD AND GLACIER OLIGOCH TA 107

distinct as in Mes. gelidus. The posterior end of the last somite

and the immediate vicinity of the penial bulb invaginations are

also much lighter than surrounding parts.

These specimens lack thé conspicuous, elliptical, swollen areas

about the ectal openings of the spermathece which Moore (’99,

p. 125; Figs. 1, 2) found in the Malaspina Glacier specimens.

Such areas are represented only by the lighter color in the im-

mediate vicinity of the openings described above. Emery and

Eisen make no mention of these areas.

A distinctly differentiated clitellum seems to be absent. The

region of XI-XIII differs from the adjacent somites only in the

obscurity of the intersegmental grooves and the slightly increased

body diameter in that part containing the penial bulbs. Transverse

and longitudinal sections of sexually mature specimens show no

increase in the thickness of the hypodermis. The apparent absence

of a clitellum causes some difficulty in distinguishing sexually

mature individuals in superficial examination but in the material

on which this paper is based it has been found that all specimens

showing distinctly protruding penial bulbs are sexually mature.

The uniform absence of a differentiated clitellum might cast some

doubt, at first thought, upon the sexual maturity of all of the

specimens but serial sections and dissections have demonstrated the

presence of spermatozoa in the spermathece, developing ova and

spermatozoa in the storage sacs, and well developed ovaries and

testes, thus furnishing proof of sexual maturity. Moore (99, p.

125) reported that “In none of the specimens examined (about

twenty in number) is the clitellum very distinctly developed, but

on the contrary is thin and scarcely extends beyond the limits of

the twelfth somite.” Eisen (’05, p. 59) found it “probably confined

for.4 IT.”

The head pore is distinct and located very near the tip of the

prostomium. The external opening is slit-like in appearance, trans-

verse in position, and surrounded by a very narrow, yellowish area.

The sete are distinctly sigmoid and arranged in fan-shaped

bundles, two lateral and two ventral. Those of a bundle are of

approximately equal development. Anterior to the penial bulb

invagination, the lateral bundles contain 2 sete, very rarely 3;

,

,

108 ' PAUL S. WELCH

posterior to that region, they contain 1 seta, very rarely 2. Anterior

to the vicinity of XX, the ventral bundles contain 2-4 setz, usually

3; posterior to that region, they contain 2 sete. The sete are

somewhat distinctive in the very abrupt bend at the distal, exposed

end (Pl. XVII, Fig. 24). The proximal end is broadly curved and

deeply imbedded in the body-wall. A comparison with the descrip-

tions of Moore and Eisen shows that the number of sete per

bundle which they report is greater than has been found in the

Mt. Rainier material. In the latter, the writer has found but a

single bundle which contained five sete. It is not possible to

determine whether the abrupt bend at the distal end of each seta

described above is a characteristic only of rainicrensis since Moore

(799, p. 126) states that in his Alaskan specimens ‘““The sete have

the form usual in the genus, being feebly sigmoid and arranged in

fan-shaped bundles, but are mostly imperfect, owing to the points

being worn or broken off.” He also reports that “Enlarged setz

are found in the ventral bundles of XI; these are about one-third

longer and much thicker than the others.” Such enlarged sete

have not been found in the specimens from Mt. Rainier. Emery

(’00b, p. 225, Fig. 10) states that “The chaetae are slightly sigmoid,

more markedly bent at their apical end (Fig. 10). They are about

a third longer in the posterior half of the body than in the anterior

segments, as it appears by comparing Figs. 12 and 13. Each

bundle consists of four nearly equal chaetae. The ventral bundle

is absent in the 12th (clitellar) segment, which receives the opening

of the sperm-duct.” From this description it might appear that

the setze resemble closely those of rainierensis but the figure which

accompanies Emery’s description portrays setz quite different from

those found in the Mt. Rainier specimens. Instead of being very

slender, approximately uniform in diameter, distinctly sigmoid,

broadly curved at the proximal end, and abruptly curved at the

distal end, they are short and very stout, having, in the posterior

bundles, a diameter of one-sixth the length. The diameter increases

from the distal end to the opposite extremity which is almost

straight. The distal end is very acute.

SNOW-FIELD AND GLACIER OLIGOCHATA 109

Internal Characters

In many respects, the internal anatomy corresponds to that

described, by previous observers, in the Alaskan form and for that

reason only new data and the features which present differences

will be discussed.

Brain.—Dissections and frontal sections show the brain

(Pl. XVII, Fig. 22) to correspond, in a general way, to the accounts

of the same organ in Alaskan specimens. It resembles more closely

the figure and description given by Moore, differing in being a

little longer than broad and in having the posterior margin dis-

tinctly but shallowly concave. However, these are minor dif-

ferences. It also resembles the figure given by Emery (’00b, Fig. 2)

except that the concavity of the anterior margin is much deeper.

A typical measurement is as follows: maximum length, 0.137 mm. ;

maximum width, 0.129 mm.; maximum thickness, 0.043 mm. A

supporting strand extends latero-caudad from each latero-caudal

angle to the body-wall.

Dorsal Blood-vessel—According to the previous descriptions

of solifugus, the origin of the dorsal blood-vessel occurs in XII.

In the Mt. Rainier specimens, this vessel becomes distinct from the

~. perivisceral blood-sinus in the posterior part of XIII or the anterior

part of XIV. In none of the specimens examined did it arise in

XII. An inconspicuous cardiac body is present.

Septal Glands.—In position, the septal glands agree with the

description by Moore (’99, p. 127) but cannot strictly be called

“Jarge”. Eisen (’05, p. 59) found the “Septal glands small” but

the position is not indicated. Of the two indefinite terms, the latter

is more nearly correct for the specimens studied by the writer.

Emery (98a, pp. 110-111) includes the following statement

in his original description of solifugus: ‘Nei segmenti 4-8 la cavita

viscerale € in gran parte occupata da ghiandole unicellulari, i cui

lunghi e sottili condotti sboccano all’ esterno in vicinanza dei gruppi

ventrali di setole.” Michaelsen’s description of Mes. solifugus

(00, p. 87) contains the following: “Liebeshdhle des 4.-8. Segm.

von grossen einzelligen Driisen erfiillt (Kopulationsdriisen?), die

in der Nahe der ventralen Borstenbiindel ausmiinden.” This state-

ment, evidently taken from Emery, contains the tentative suggestion

,

110 PAUL S. WELCH

by Michaelsen as to the character of the glands. Emery (’00b,

pp. 226-227) in his later and more complete paper, describes these

glands as follows: “In the segments 4-8, the most part of the

body-cavity is filled by unicellular glands (Fig. 11 gl); their very

thin excretory prolongations form numerous threads directed

towards the ventral side, which can be easily followed on the

sections to the sides of the ganglion chain. Their thinness and

flexuous course make it difficult to follow them to their end on

the surface of the skin. I believe that they converge towards the

bundles of chaetae of the ventral series. As Mr. Michaeélsen writes

me, these glands may be regarded as morphological equivalents to

those gland-cells which in other Enchytraeids are related to the

chaetae of the genital segments. In Melanenchytraeus, I don’t

think that these glands have any relation to the function of re-

production, because I find them no less developed in immature

specimens.” No mention of such special unicellular glands is found

in the descriptions of Moore and Eisen and the writer has found

no evidence of them in his material. Since the position of these

unknown glands coincides with the position of the septal glands,

as described by Moore and as found by the writer in Mt. Rainier

specimens, it might be suspected that the two have been confused.

Emery (’00b, Fig. 11) figures these glands as they appear in a

longitudinal section of the body and although the component cells

are not associated in close, compact masses, they are aggregated

into rather loosely associated groups and columns with their pro-

longations approaching each other and extending in the same direc-

tions. The appearance of the whole very strongly suggests loosely

constructed septal glands and since Emery worked with a very few

sexually mature specimens which were not in the best state of

preservation, the writer is inclined to suspect these masses of

“unicellular glands” of being the usual series of septal glands.

Nephridia—The nephridia (Pl. XVII, Fig. 25) agree closely

with previous descriptions. A well-developed, ciliated nephrostome,

borne on a slender base, comprises the anteseptal part. The post-

septal region is enlarged, somewhat lobate, and slightly compressed.

The structure of the interior is of the usual mesenchytreid type.

The efferent duct arises from the ventral surface of the postseptal

SNOW-FIELD AND GLACIER OLIGOCH2TA 111

part near the caudal end. In the specimens examined, there is con-

siderable variation in the size and shape of the nephridia in different

regions of the body but the general structure is fairly constant.

The first pair is located on VI/VII. Moore (’99, p. 127) found

nephridia “in every somite posterior to VII.” No nephridia have

been found on XI/XII and XII/XIII in the Mt. Rainier specimens.

Lymphocytes—Lymphocytes are very scanty, in some speci-

mens almost absent. A few scattering cells occur in the anterior

region and occasional ones more caudad. They are small, elliptical,

nucleated, and contain pigment-granules.

Spermiducal Funnel.—The spermiducal funnels (Pl. XVII, Fig.

23) depart somewhat from Moore’s descriptions of Alaskan spec-

imens of solifugus. Instead of being constricted at the middle

and bent upon themselves so that the free end is directed caudad,

they show only a slight diminution in diameter and a slight bend

at the middle so that the free end is directed cephalo-dorsad. A

much greater disagreement is found when comparison is made with

Emery’s figure (’00b, Fig. 16) of the funnel which is represented

as a very short, funnel-shaped organ which is broader than long.

However, Emery states that his figure was drawn from a recon-

struction. The length is about three times the maximum diameter,

a typical set of measurements being as follows: length, 0.344 mm. ;

diameter, 0.113 mm. The collar is entirely absent.

Sperm Duct.—The sperm duct is very long and of approx-

imately uniform diameter. Because of its coiled and contorted

condition, the exact determination of its length has not been possible.

It extends from the end of the spermiducal funnel into the ovisac;

forms contorted masses in XIII and XIV; continues caudad within

the ovisac to XX; thence is reflected cephalad to XII to unite with

the atrium. Throughout the entire course it is characterized by

numerous coils and curves. Its extent is represented by the com-

bined length of sixteen somites plus an allowance of the length

of several somites to compensate for the contortions. Except for

a very small part at the end of the spermiducal funnel and at the

union with the penial bulb, the entire duct is contained in the ovisac,

and does not, according to the writer’s observations, enter either of

the sperm sacs. Moore (’99, p. 129) found that, in his material,

,

112 PAUL S. WELCH

the sperm duct on the right side lies within the ovisac and extends

to the region of XVIII, but the one on the left side lies free in

the body-cavity, extending also to the region of XVIII. Eisen’s

description contains no account of these ducts.

Sperm Sacs.—The sperm sacs are a pair of caudal evaginations

of XI/XII, one on each side of the median line, which lie latero-

ventrad of the digestive tract and extend to XV or XVI. In the

specimens examined, they are rather small, but both are of about

equal development. Both lie within the ovisac and both contain

masses of developing spermatozoa. The structure of the walls of

these sacs is identical with that of the septa.

Moore (99, p. 128) found a different condition in Alaskan

material. The sac on the right side is almost rudimentary, ex-

tending only into XII, while the one on the left side is well

developed, extends caudad to XX, and is apparently not contained

within the ovisac. Other descriptions do not include data on the

structure and relations of these sacs. Allowing for a liberal

variability, such differences seem rather large for intra-species varia-

tion.

Ovisac.—The ovisac is formed by the caudal outgrowth of

XII/XIII. It arises as a single, well-developed sac and extends

caudad, ventrad to the digestive tract, to the posterior part of XIII

or to XIV where it bifurcates, forming two branches, one on either

side of the median line, which extend to the vicinity of XX. There

is some variation in the length since specimens were examined in

which the caudal terminations were in XXII, while in others they

were in XIX. As stated above, the ovisac contains the sperm ducts

and the sperm sacs. In addition, it contains masses of developing

ova. Here, again, is an interesting divergence from the condition

described by Moore (’99, pp. 129-130) who found, in the Alaskan

material, that the ovisac is single throughout its entire length and

contains only the right sperm duct and the masses of developing

ova. The length, however, is very similar in both cases.

Penial Bulb.—In the general plan of structure, the penial bulb

(Pl. XVII, Figs. 20, 26) agrees with the description by Eisen

(705, p. 60) for Alaskan specimens. However, a number of dif-

ferences exist in some of the finer structural detail. The whole

SNOW-FIELD AND GLACIER OLIGOCH TA 113

organ is of the mesenchytrzid type as described by Eisen (’05, p. 7)

and consists of three sets of structures, viz., the penial bulb proper,

the atrium and its associated parts, and the accessory glands. The

whole organ is conspicuous ‘in size so that both bulbs occupy the

greater part of the ccelom in that region.

The penial bulb proper is situated on a deep invagination which,

in transverse section of the body, is slit-like but in longitudinal

section appears as a narrow channel leading, at its inner extremity,

into an expansion which takes the form of a chamber, narrow in

dorso-ventral dimension but much wider in transverse dimension.

This inner chamber caps the ental part of the invagination like the

top to a mushroom. Structurally, the wall of the invagination is

essentially a continuation of the body-wall. The ectal end of the

sperm duct connects with the inner, expanded chamber. The body

of the bulb is composed of (1) a large number (over twenty-five)

of multicellular glands, (2) scattering unicellular glands, (3) a

large number of muscle-strands, and (4) the ectal end of the sperm

duct. The multicellular glands are pear-shaped, the expanded ends

being entad of the invagination. Each is composed of a number

of gland cells aggregated in the expanded ends and a narrow,

tapering extension, composed of the elongated ends of the gland

cells, which connects with the penial invagination. None of these

glands opens into the sperm duct. The unicellular glands are

sessile, very inconspicuous, and are scattered singly about the in-

vagination into which they apparently open. They are the only

glands which occur laterad of the invagination. In the interior

of the bulb, muscle-fibers extend in different directions. They lie

between the various glands and many of them are attached to the

wall of the invagination. They vary in size from very fine threads

to rather strong strands. The ectal end of the sperm duct, which

is contained within the body of the bulb, has the usual structure

except that it is surrounded by a very strong, longitudinal muscle-

coat which is apparently derived from the longitudinal muscle-layer

of the body-wall.

Within the penial bulb but near its ental surface, the sperm

duct begins to expand into the atrium so that a small portion of

the ectal part of the latter is included within the envelope of the

,

114 PAUL S. WELCH

bulb. The atrium is a stout, fusiform organ, about 0.3 mm. long

and 0.13 mm. in maximum diameter. Its histological structure is

very similar to that indicated in Eisen’s figure (’05, Pl. VIII, Fig. 1),

except that the epithelium on the surface does not seem to be

as distinct and thick. At the ental end of the atrium is a set of about

five large, club-shaped, multicellular atrial glands, arranged in a

whorl. These glands extend into the ccelom and are conspicuous

organs in sections of that part of the body.

A number of large, multicellular, pear-shaped, accessory glands

are present. They lie just outside of the envelope of the bulb and

open into the invagination, commonly at its origin. In general

structure, they resemble the multicellular glands within the penial

bulb. The surrounding envelope is very delicate and it is difficult

in some of the specimens to determine just how many of the glands

at the edge of the bulb are to be classed as accessory.

The structure of the penial bulb and its associated parts in

solifugus has been briefly described by Moore (’99, p. 129) and

Eisen (’05, pp. 59, 61) as it occurred in the Alaskan material which

they examined, and a comparison with the Mt. Rainier specimens

is of interest. Moore states that “Before entering the atrium in

somite XII the recurrent limbs of the sperm ducts expand into

narrow fusiform sacs (........ ), having glandular, epithelial and

muscular walls, which receive the ductules of a group of unicellular

spermiducal glands. This structure probably serves to form and

eject the spermatophores. A narrow curved duct, which is also pro-

vided with some unicellular glands, perforates the mesial wall of the

atrium and opens into its lumen. Unlike the remainder of the male

efferent apparatus, the atrium (........ ), is, in part, of ectodermal

origin, as is indicated by the pigmented lining epithelium. It

is a spheroidal thick-walled partly eversible sac, with an internal

cavity having a mushroomlike shape in the retracted organ. Its

walls are composed of a cuticle-covered, rather deep, pigmented and

perhaps glandular epithelium, surrounded by a thick muscular layer

in which the fibres are partly longitudinal, but largely radial,

especially about the place of entrance of the sperm duct. A number

of groups of unicellular glands are attached to the organ, and

probably empty into its lumen.”

SNOW-FIELD AND GLACIER OLIGOCH ATA 115

At first sight, it might appear that a radical difference exists

between the structure of the Alaskan and Mt. Rainier specimens.

In the first place, a difference in the use of terminology is evident.

Moore applies the term atrinm to the structure which the writer

and others call the penial bulb, and speaks of the expansion of the

sperm duct just entad of the bulb as “narrow fusiform sacs”. The

writer follows Michaelsen (’00, p. 9) and Eisen (’05, p. 4) in using

the term atrium to designate the enlargement of the sperm duct

which is situated just entad of its union with the penial bulb. Ap-

parently, Moore regards the atrial glands and the multicellular

glands within the penial bulb as “groups of unicellular glands” rather

than multicellular glands as described by the writer. If this in~

terpretation of Moore’s description is in error, then the structure

of the penial apparatus in the Alaskan specimens is very different

from that described in the present paper. No distinction is made

in the above-quoted description between the penial glands within

the bulb and the accessory glands.

Eisen (05, pp. 59, 61) describes the penial apparatus in soli-

fugus as follows: “A large atrium in which opens about eight atrial

glands of large size. Many large accessory glands open along the

base outside of the penial bulb. About fifteen penial glands inside

pre penial bulb. .... . . . . . .. The accessory glands, which

are characteristic, open along the base of the penis outside of the

bulb. They are long and of trefoil shape, with enormous long

narrow ducts.” It will be noted that Eisen found a greater number

of atrial glands in his material. Furthermore, the accessory glands

are evidently much longer and the number of penial glands in the

bulb greater than in rainierensis.

Emery (’00b, pp. 227-228, Fig. 16) describes the penial ap-

paratus as follows: “The last tract [Sperm duct] forms a

spherical bulb (a), but before reaching it the tube presents a fusi-

form swelling (c), whose wall is very thick and made of long cells,

directed radially on the transverse section, the lumen being not

widened. Bundles of prostatic (spermiducal) glands (b) are re-

lated to the bulb; another little group of glands (e) lies around the

tube, above its fusiform thickening.” Some difficulty is experienced

in interpreting this description, expecially when the figure is con-

,

116 PAUL S. WELCH

sulted. The spherical body of the bulb and the atrium agree with

the other descriptions but the “prostatic glands” are represented

as large, rather numerous, lobular organs which lie out in the body

cavity, opening into the penial bulb much as do the corresponding

organs in Mes. gelidus. The other group of glands referred to is

of uncertain identity, judging from either the description or the

figure. Emery’s figure was made from the reconstruction of a

series of sections and is possibly not fully dependable, although it

seems improbable that a mistake could have been made in the

matter of so large a group of glands as those which he calls

prostatic. Assuming that his observations have been fairly correct,

the penial apparatus differs from those described by Eisen and

Moore as well as from rainierensis.

Spermathece.—The spermatheca, in all of the specimens ex-

amined, consists of (1) a short, stout, cylindrical duct, covered

externally, in part, by numerous attenuated, unicellular glands,

(2) two almost oppositely placed, elongated, cylindrical diverticula

which are directed caudad, and (3) an elongated, slightly curved

ampulla which decreases slightly in diameter towards the ental end

and joins the digestive tract independently on its lateral aspect.

The character of the area surrounding the external opening of the

duct has already been discussed.

Certain variations are apparent when these organs are com-

pared with the descriptions of solifugus from other localities.

Moore (’99, pp. 130-131) found three spermathecal diverticula. He

also found that the ampulle of the two spermathecz unite to form

a short duct before joining the digestive tract on its dorsal side.

No mention is made of unicellular glands on the duct. Eisen’s

description (’05, p. 60; Fig. 32b) agrees with that of Moore in

almost every respect. However, his figure shows, on one of the

spermathece, one diminutive and three equally developed diverticula,

indicating a possible variation, although no mention is made of it

in his description. Emery’s original description of solifugus (’98a,

pp. 110-111) contains the following statement: “I ricettacoli del

seme non communicano con l’intestino; sono in continuita l’uno

coll’, altro ed hanno ciascuno, alla base della loro ampolla, due o

tre diverticoli.” His more complete paper (’00b) corroborates this

SNOW-FIELD AND GLACIER OLIGOCH ETA 117

statement. It appears, from the above, that specimens with as

few as two spermathecal diverticula were found. The reported

absence of the communication of the ampulla with the digestive

tract may be an error as has been suggested by Moore. Emery

(‘00b, p. 230) re-examined his material and found no connection

but states that the spermathecz lie in close contact with the in-

testine and points out the possibility that his single sectioned

specimen might be not fully mature or abnormal.

Pigmentation.—All of the specimens from Mt. Rainier are

deeply pigmented. Microscopic examination of sections of all parts

of the body shows that the hypodermis bears a heavy load of minute,

dark brown, non-staining pigment-granules, especially in the outer

ends of the cells. This pigmentation extends to the internal organs.

The chloragog cells, which first appear in IV and are present

throughout the remainder of the body, are heavily loaded with pig-

ment. It also occurs in the glands surrounding the bases of the

setz, in the lymphocytes, in the lining of the buccal cavity and the

pharynx, in the spermathecal duct, in the lining of the penial in-

vagination, in the nerve cord, and in the brain. It will be noted

that this distribution of pigment corresponds closely with that

described by Moore (’99, p. 127) for specimens of solifugus from

Alaska. Eisen (’05, pp. 59, 60) states that the pigment is dis-

tributed in the body-wall and also in most of the internal organs

“even in the ganglia and the brain” but does not specify further

detail.

Summary of Comparisons—The variety, rainierensis, differs

from the Alaskan specimens of solifugus in the following respects:

(1) the smaller number of sete per bundle, (2) the absence of

enlarged sete on XI, (3) the origin of the dorsal blood-vessel in

XITI-XIV, (4) the concavity of the posterior margin of the brain,

(5) the constant presence of only two diverticula on the sperma-

theca and the independent opening of each spermatheca into the

lateral wall of the digestive tract, (6) the shorter accessory glands,

the smaller number of atrial glands, the larger number of multi-

cellular glands within the penial bulb, and the straighter spermi-

ducal funnel, and (7) the complete enclosure of the sperm sacs

and sperm ducts by the ovisac. All of these differences seem

,

118 PAUL S. WELCH

to be constant and are sufficient to raise the question as to whether

they are too wide to be considered within the range of intra-

species variation. However, they are differences of narrow mar-

gin and when compared with the sum total of the points of

agreement with solifugus as described, the writer is convinced

that the Mt. Rainier material is not a distinct species but can be

considered only as a new variety.

BIOLOGICAL NOTES

As stated before, all of the information concerning the living

specimens has been furnished by Mr. Flett. He found Mes. soli-

fugus var. rainierensis abundant on the higher snow-fields and

glaciers of Mt. Rainier in early summer. The collection which

has furnished the material for the preceding description was made

on June 17, 1915, at an altitude of 7,500 ft. Nothing is known

concerning the winter or early spring conditions since at those

seasons collections at such heights are not possible. These worms

occur on snow-fields which seldom thaw during the summer and

they evidently pass the entire existence, generation after genera-

tion, in the snow and ice. Mr. Flett states that on one occasion

he has seen what he thought was this worm at an elevation of

only 6,000 feet where the snow melts and grass and flowers grow

in profusion during three or four months of the year. However,

this was an unusually low altitude for these worms since they

occur regularly and more abundantly much higher up the moun-

tain on the permanent snow-fields and on the snow and ice of the

glaciers. The writer has not had the opportunity of studying

specimens from an altitude as low as 6,000 feet, but if the worms

seen at that level are solifugus var. rainicrensis, as Mr. Flett thinks

they are, it appears that those individuals which chance to be devel-

oped at the unusually low levels must pass a part of the life history

in midsummer on or in the ground.

On the glaciers, these worms coil up so as to appear as small

spherical black dots on the snow or solid ice and it requires a

considerable exposure to sunshine to warm them up to the active

stage. According to the observations of Bryant (Moore, ’99, p.

134), the specimens of solifugus on Malaspina Glacier, Mt. St.

SNOW-FIELD AND GLACIER OLIGOCHZTA 119

Elias, “remain on the surface during the night; but when the sun

appears in the morning they again burrow into the snow”. This

does not agree with the observations of Mr. Flett for the variety

rainierensis since he has noticed no tendency on the part of the

worms to avoid sunlight, the warmer the day the more active they

become, this activity being manifested on the surface. The period

of greatest activity is usually from the middle of the afternoon to

about five or six o’clock.

No data on the associated life are available except the state-

ment by Mr. Flett that snow alge (“Spherella nivalis”) occur in

great abundance and that spiders and snow-fleas (Collembola) are

present.

The question of the food of a worm living in such a habitat is

of considerable interest. Obviously, in the case of those individ-

uals living on the permanent snow-fields and the ice of the glaciers,

the number of substances serving as food are extremely limited.

Emery (’00b, p. 226) found the contents of the intestine of Alaskan

specimens, especially in the posterior part, to consist of “very fine

crystalline mineral detritus, which seems to be the ordinary food

of this worm”. An examination of the intestinal contents in the

Mt. Rainier specimens yielded practically no definite data. A cer-

tain amount of what seems to be fine, angular, mineral particles

is present. However, the conspicuous content was a more bulky

material, which the writer was unable to identify. In some re-

spects, it has the appearance of partly disintegrated vegetable

matter. This material was found in every specimen examined and

evidently represents a part of the usual food.

GENERAL CONSIDERATIONS ON SNOW-FIELD AND GLACIER WORMS

Temperature Relations——A striking thing about the environ-

ment of these enchytreids is the very low temperature of the me-

dium in which they live. They exist and carry on their life pro-

cesses under freezing temperatures and in a medium of snow and

ice. Species, such as Mes. gelidus, which regularly occur at an

altitude below the limit of permanent snow-fields evidently pass

,

120 PAUL S. WELCH

a part of the life history on or in the ground, but aside from the

midsummer months they are covered with snow and live in the

latter or else in the earth beneath it. In either case, they are pass-

ing the greater part of the year in cold conditions, appearing in

the melting snow in early spring. On the other hand, solifugus,

which regularly inhabits the permanent snow-fields and the ice of

the glaciers, spends its entire existence, generation after generation,

under these conditions. Apparently, it must deposit its eggs in

the snow, on the ice, or in the small pools of ice water which some-

times occur on the surface of the lower parts of the glaciers, and

the young worms must be able to withstand the rigid conditions and

successfully solve their problems of maintenance.

Pigmentation —Nothing is known concerning the role of the

large amount of pigment. Reference has already been made to

the speculative discussion of this problem by Moore (’99, pp. 135-

142). It may be related to the maintenance problems of heat or

light, or both, but until some careful observations and experiments

are made no definite conclusions can be drawn. If such pigmenta-

tion were confined exclusively to glacier forms the circumstantial

evidence might be stronger in favor of a theory that it is an adapta-

tion to some of the factors peculiar to that environment, perhaps

light and temperature, but the fact that species other than glacier

forms are known (Mes. harrimani Eisen, Mes. obscurus Eisen,

Mes. maculatus Eisen, and others) which possess similar pigmenta-

tion throws some doubt on such an assumption. If it be true, as is

suspected in some cases, that the younger stages of these glacier

worms are not pigmented, a critical study of the life history may

be necessary to the accurate solution of this problem.

Other Snow-field and Glacier Worms.—It is possible that

future investigations of the northern glaciers and the arctic snow-

fields will reveal still other enchytreids which occupy these frigid

habitats and extend the knowledge of the distribution of the species

already known. Certain arctic explorers make mention of the

presence of “worms” on the snow and ice and while no hint is given

of their identity, it is quite possible that they are enchytrzids.

Mr. Flett states that he found a snow-worm in the Olympic Moun-

tains which occurred in enormous numbers, making the snow black,

SNOW-FIELD AND GLACIER OLIGOCH2TA 121

and which resembles Mes. solifugus var. raimierensis in size and

general appearance, but since material has not been secured its

identity is unknown. Among the collections from Mt Rainier,

there is at least one other enchytrzid which appears to be distinct

from those described in this paper but has not been carefully studied.

Thus far, all of the known glacier worms belong to the genus

Mesenchytreus. While our knowledge concerning the geographical

distribution of Enchytreide is incomplete, it appears fairly certain

that the family is one of temperate and frigid distribution. Ude

(701, p. 23) found, among other things, that available data showed

that “Die Gattungen Mesenchytraeus und vielleicht Henlea (vergl.

H., veniriculosa (Udek.) lassen in ihrer Verbreitung Cirkumpolaritat

vermuten.” Certain other genera (Bryodrilus, Lumbricillus, and

others) have representatives in the arctic zone but none of them

seem to have been reported as living continuously in snow and

ice. Whether this habit is confined to Mesenchytreus is a problem

for future investigation.

122 PAUL S. WELCH

BIBLIOGRAPHY

Ersen, G.

705. . Enchytreide of the West Coast of North America. Harriman

Alaska Expedition, 12:1-166. 20 pi. New York.

Emery, C.

08a. Diagnosi di un nuovi genere e nuova specie di Anellidi della

famiglia degli Enchytraeidae. Atti della R. Accad. dei Lincei,

(5), 7:110-111.

’98b. Uber einen schwarzen Oligochaten von den Alaska-Gletschern.

Verhandlungen der Schweizerischen Naturforschenden Gesell-

schaft bei ihrer Versammlung zu Bern den 1., 2. und 3. August.

p. 89. D. Sektion fiir Zoologie.

’08c. Sur un Oligochete noir des glacier de l’Alaska. Bull. de la Société

Zoologique Suisse, (Rev. Suisse Zool., V, Suppl.) pp. 21-22.

Genevé Assemblée générale de Berne. [Not seen].

00a. Uber zoologisches Material vom Eliasberge in Alaska. Die For-

schungsreise S. K. H. des Prinzen Ludwig Amadeus von

Savoyen, Herzogs der Abruzzen, nach dem Eliasberge in Alaska

im Jahre 1897. Von Dr. Filippo de Filippi. Ubersetzt von Prof.

Baron G. Locella. Leipzig. Anhang D, pp. 236-245. 1 pl.

Abstract by Th. Krumbach in Zool. Centralbl., 8 :812-813.

’00b. On Melanenchytraeus solifugus. The Ascent of Mount St. Elias

[Alaska] by H. R. H. Prince Luigi Amedeo Di Savoia Duke of

the Abruzzi, Narrated by Filippo de Filippi. Illustrated by

Vittorio Sella and Translated by Signora Linda Villari with

the Author’s Supervision. Westminster. Appendix D, pp. 224-

7a} Woe He)

MICHAELSEN, W.

700. Oligochzta. Das Tierreich, 10 Lief. XXIX+575 pp. 13 fig. Berlin.

Moore, J. P.

99. A Snow-inhabiting Enchytraeid (Mesenchytreus solifugus Emery)

collected by Mr. Henry G. Bryant on the Malaspina Glacier,

Alaska.

Proc. Acad. Nat. Sci. Phil., pp. 125-144. 1 pl.

Ube, H.

01. Die arktischen Enchytraiden und Lumbriciden sowie die geogra-

phische Verbreitung dieser Familien. Fauna Arctica, 2:1-34.

2 pl.

WE cH, P. S.

16. Glacier Oligocheta from Mt. Rainier. (Abstract of paper read

before the thirteenth annual meeting of The American Society

of Zoologists, Dec. 28, 1915). Science, 43 :143.

Fig.

Fig.

Fig.

Fig.

Fig.

Fig

SNOW-FIELD AND GLACIER OLIGOCHATA

EXPLANATION OF PLATES

123

ABBREVIATIONS

ac. gl., accessory gland.

atr., atrium.

atr. gl. atrial glands.

cut., cuticula.

ec. op., ectal opening.

hyp., hypodermis.

in. pen. gl., intra-penial glands.

lum. amp., lumen of ampulla.

lum. div., lumen of diverticulum.

Ov’s., ovisac.

pen. b. i, penial bulb invagination.

pen. ch., penial chamber.

pen. gl., penial glands.

pen. po., penial pore.

r.m., retractor muscle.

sp. d., sperm duct.

sp’r., spermatheca.

sp’r. d., spermathecal duct.

sp. Ss. sperm sac.

I-XXXV., somites.

PiLate XIV

Mesenchytreus gelidus

Diagram of XI-XXXV, showing position and extent of ovisac,

sperm sacs, spermiducal funnels, and sperm ducts. Broken lines

indicate omission of somites.

Diagram of I-X, showing extent of the exceptionally large

spermathece, The broken lines across spermathece in posterior

part of VIII indicate most anterior observed termination of these

organs.

Longitudinal section through ectal region of spermatheca.

Lymphocytes, indicating abundance of pigment-granules in cyto-

plasm.

Chloragog cells. Pigment-granules distributed through cells.

Longitudinal section through ectal opening of spermatheca, showing

unicellular glands which occur in connection with end of

spermathecal duct.

124 PAUL S. WELCH

PLATE XV

Mesenchytreus gelidus—cont.

Fig. 7. Spermatheca.

Fig. 8. Spermatheca.

Fig. 9. Sete. Bundle from ventral row.

Fig. 10. Brain.

Fig. 11. Penial bulb and associated structures.

Figs. 12-13. Spermathece from one specimen, drawn to same scale, show-

ing a rather exceptional form of variation in development.

Fig. 14. Nephridium.

Figs. 15-17. Diagrams of different forms of spermiducal funnel.

Fig. 18. Nephridium.

Pirate XVI

Mesenchytreus gelidus—cont.

Fig. 19. Longitudinal section through penial bulb.

PLaTeE XVII

Mesenchytreus solifugus var. ratnierensis

Fig. 20. Penial bulb as it appears in transverse section of body.

Fig. 21. Spermatheca.

Fig. 22. Brain.

Fig. 23. Spermiducal funnel.

Fig. 24. Sete.

Fig. 25. Nephridium.

Fig. 26. Penial bulb and associated structures.

oa

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PLATE XVI

P. S. WELCH

Sf{ote

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PLATE XVII

WELCE

iE. S:

ON THE SO-CALLED INTESTINAL GLANDS IN

NECTURUS MACULATUS

By Harotp TupPpeR MEapD

From the Zoological Laboratory of the University of Chicago

Introduction.

Imbedded in the submucosa and connected to the mucosa in

the intestines of Necturus are groups of cells whose function has

not been determined. The finer structure and function of these

groups of cells constitute the object of the present work.

Groups of cells of similar character have been described in

Proteus, the European Salamander, Newt, Triton and Amblystoma,

but have never been mentioned in connection with other animals.

It is of interest to note that forms as closely allied as Rana do

not possess these groups of cells, nor, according to a recent paper

by A. M. Reese, does the Alligator. Since the forms mentioned

above represent two of the three suborders of Urodeles it is prob-

able that they are characteristic of Urodeles only.

The function of these groups of cells may be similar in the

different animals which possess them, but two views have been

held as to their function. One view is that they are glands dis-

charging into the intestine. This other view is that they serve as

proliferation centers where the epithelial cells which constitute the

musoca are produced.

Various names, more or less suggestive of function, have been

applied to these structures, such for example as “gland,” “Sprossen”

(sprout), “Bud,” “Zapfen” (spigot) and “Ersatzzellen” (compen-

sation cells). It is clear that it is not advisable to use for these

structures, a name which suggests a function until their function

has been ascertained. So, for the sake of convenience, I shall use

the term “protuberance” inasmuch as it does not suggest a function.

In the present work I shall confine myself to these protuber-

ances in Necturus.

Review of Literature.

Hoffman (1878) was probably the first writer to mention these

protuberances in Necturus. I have not been able to see Hoffman’s

work but according to B. F. Kingsbury, Hoffman described these

,

126 HAROLD TUPPER MEAD

protuberances in Necturus as glands and “speaks of their almost

circular opening upon the surface epithelium of the intestine.”

Oppel in 1889 saw protuberances in the intestinal submucosa

in Proteus anguineus and pronounced them glands (Driisen). He

noted that mitotic cells were abundant in the structures and in the

intestinal mucosa in the immediate vicinity of the structures.

Protuberances in the intestinal mucosa of Triton were de-

scribed in 1892 by Bizzozero. He referred to them as groups of

’ compensation cells (Ersatzzellen) and sprouts (Sprossen). He

said that cells proliferate not only at the base of the mucosa but

press the wall of the mucosa out in places to form sprouts. For

saying that these sprouts are epithelial, he gave the following rea-

sons, which are summarized from the translation; (1) their gen-

eral character and constitution are those of epithelial tissue, (2)

cells can be seen in all stages of transformation from the cubical

cells of the sprout to the columnar cells of the mucosa. He re-

marked that mucous granules can be seen between the epithelial

elements and that a great many mitoses are present in the sprouts.

In Salamander protuberances have been described by Nicholas

(1894) who called them proliferation buds (burgeons germinatifs).

Nicholas said that they represent cell proliferation centers, and

that they could not be glands inasmuch as they possess no lumen.

He said that dividing cells were to be seen only in the buds (bour-

geons) or in the surface epithelium near the neck of a bud.

Kingsbury in 1894 working on the enteron of Necturus re-

garded these protuberances as glands. He wrote “my study of

them in Necturus would, however, lead me to regard them as

glands. The arrangement of the cells as if surrounding a lumen,

and indeed a lumen itself, which Nicholas declared did not exist

in these structures, could be seen upon almost all of my sections

in some of the glands. I was unable, however, quite satisfactorily

to demonstrate the existence of a neck, although it seemed in numer-

ous glands to be quite well indicated.”

The work of Bizzozero was resumed and confirmed by Sac-

erdotti in 1896. The latter also working on Triton sought to

ascertain the relation between the period of cell division and the

period of mucous secreting activity. He determined that karyo-

INTESTINAL GLANDS OF NECTURUS MACULATUS 127

kinetic forms were assumed by cells which had already begun to

secrete mucous, that these karyokinetic cells are found in the deeper

parts of the epithelial layer but more especially in the epithelial

spigots (Zapfen) pressing into the connective tissue. He added

that occasionally and exceptionally karyokinetic cells were seen

near the surface of the epithelium. Sacerdotti explained their

presence in that region by saying that the cells in the animal con-

cerned were possessed of very great growth capacity and thus cer-

tain mitotic cells had been forced out of the epithelial spigots and

had reached the surface while still in mitosis.

Bates in 1904 described protuberances in the American Ambly-

stoma and remarked that their structure would suggest glandular

activity yet said he was not able to demonstrate the existence

of a lumen.

Technique.

Inasmuch as the main object of my work was to determine

the finer structure of these protuberances and with a view to dis-

tinguish whether they were glands or not, I endeavored to obtain

a technique which would give to glandular secretions a differential

coloration. For this purpose some of Dr. R. R. Bensley’s special

methods for glands were used.

Mallory’s triple stain (Guyer, Animal Microcology, p. 172)

was used extensively. It proved to be especially rapid and prac-

tical for general work. It gave a conspicuous differential colora-

tion to connective tissue and epithelial tissue. —

Weigert’s Hematoxylin (Guyer, p. 178) proved to be very

effective for preparing slides for the purpose of studying mitosis

and details of nuclear structure.

Some of the animals were killed very soon after being brought

into the laboratory, others were kept in an aquarium for a few

months. Most of the fixing was done in Gilson’s fluid but some

fixing was done in Bensley’s Acetic Osmic Bichromate fluid.

Description.

These protuberances in Necturus are located for the most part

at the peripheral or outer parts of the folds. Occasionally one is

found on the side of a fold a short distance from the peripheral

bend. In one animal, however, out of over twelve which were

,

128 HAROLD TUPPER MEAD

studied, in which the intestinal mucosa was more abundant and

more folded, I saw a few of these protuberances occupying posi-

tions at the very central part of the sections at the central apices

of some of the folds.

As for the distribution of these protuberances throughout the

length of the intestine, I found that they are more abundant an-

teriorly than they are posteriorly. To ascertain this, I made a

count of the number of protuberances that appeared in cross sec-

tions in the respective regions. The count involved twenty slides

from each region from about five different animals. The results

of the count are here summarized.

Region vanes SENG che

Duodenal region 109 43 70.3

Middle intestine 104 45 66.6

Rectum 75 37 52.6

Thus it is seen that the number of protuberances decreases

with distance from the pylorus.

The size of these protuberances varies in diameter from about

50 micra to about 127 micra. In length they vary from about 127

micra to about 293 micra. These measurements made with a stage

micrometer and an ocular micrometer, are the extreme measure-

ments of a great many taken.

The shape of these protuberances is naturally variable but it

is usually possible to distinguish three parts. (1) the body, that

part of the structure which lies wholly outside the mucosa, (2)

the mucosal portion, or the portion that lies wholly within the

mucosa and (3) the neck which connects the body and the mucosal

portion. I shall describe each part separately and in detail.

The body is commonly roughly spherical in shape but is also

frequently columnar or conical with the point more or less blunt.

The body is also frequently branched. These structures are in-

variably connected to the mucosa. In mounted sections one sees

many bodies apparently not connected to the mucosa but by tracing

such bodies through serial sections a connection with the mucosa

could always be demonstrated.

INTESTINAL GLANDS OF NECTURUS MACULATUS 129

Those protuberances that are situated quite at the peripheral

ends of the folds almost always extend into the submucosa in a

direction perpendicular to the mucosa. If however the protuber-

ances are situated on the sides of the folds, as related above, the

body part bends over so as to lie close to the mucosa. In other

words, the body parts of the protuberances always extend in a

direction radiating from the center of the intestine.

The cells in the body portions are polygonal in shape. The

nuclei are more or less spherical and occupy nearly all of the cell.

I studied carefully the narrow zone of protoplasm which surrounds

the nucleus in cross sections to see if I could discover any granules

the presence of which would suggest a secretary activity, but none

of my preparations showed any.

I paid particular attention to the arrangement of cells within

the body, and was unable to demonstrate a universal definite order

of arrangement. This is contrary to the findings of Kingsbury,

who stated that the cells were arranged as if surrounding a

lumen, and added that a lumen itself could be seen in some of his

sections. I was unable to discover a lumen nor did I find an ar-

rangement of cells that would suggest the presence of a lumen.

Therefore, I have concluded that these protuberances cannot

be glands. I consider the presence or absence of a lumen a sufficient

criterion on which to base such a conclusion, for if these struc-

tures were glands the existence of a duct through which the se-

cretions might pass and a corresponding arrangement of cells

would be necessary.

The mucosal portion is that portion which extends into the

epithelial mucosa. It commonly spreads out within the mucosa so

that cross sections appear fan shaped. There is a gradual tran-

sition in the shape of the cells of the body of the protuberance and

the columnar cells of the mucosa. The transition takes place in

the mucosal portion of the protuberance. The cells in the mucosal

portion of the protuberance become more and more elongate and

are arranged in crescentic layers in optical section, as if suspended

hammock-like from the outer boundary of the mucosa. The far-

ther the cells are from the center of the protuberance, the more

columnar they are. The nuclei become more and more oval.

130 HAROLD TUPPER MEAD

The neck of the protuberance is the portion at the peripheral

boundary of the mucosa, which connects the body of the protuber-

ance to the mucosal portion. It is almost always somewhat

constricted.

Cells in various stages of mitosis are frequent in all parts of

the protuberance. To determine the ratio of mitoses present to

the total number of cells in the protuberances, I made a count in-

volving several thousands of cells and calculated that the ratio of

mitotic cells to the total number of cells is one to forty-one. There

are an average number of 39 cells in a section of a protuberance.

Thus there is an average of about one

mitotic cell in a protuberance. In

some protuberances I saw three cells

in mitosis while, on the other hand,

there were many sections of protuber-

ances that did not show a single mi-

tosis.

It is significant that not one case

of mitosis was seen in the mucosa at

any considerable distance from a pro-

tuberance.

Upon these facts I have con-

cluded that cells which are to compose

k ; the intestinal mucosa in Necturus, are

_ Camera lucida drawing of a por- if

tion of a cross section of the mu- formed in these protuberances. It

cosa of the mid intestine of Nec-

turus maculatus showing protuber- would seem that the cells are forced

ance P, lumen L, neck N, mitotic

cells M. The cell walls were not through the neck of the protuberance,

drawn by means of a camera lu- i , : -

cida. Spencer Ob. 10X, Oc. 4. while perhaps sometimes still in mi-

totic condition. In the mucosal portion of the protuberance, the

cells appear to be forced in a lateral direction along the mucosa.

Since mitotic cells are not found at points along the mucosa except-

ing near the protuberances, it may be concluded that the intestinal

mucosal cells do not divide after they have become functional cells.

According to this view, these protuberances in Necturus are

cell proliferation centers for the mucosa as was concluded for some

other Urodeles by Bizzozero and Nicholas.

Mitchell, South Dakota.

FILICOLLIS BOTULUS N. SP., WITH NOTES ON THE

CHARACTERISTICS OF THE GENUS*

By H. J. VAN CLEAVE

Lithe’ founded the genus Filicollis (1911:30) upon the char-

acteristics of the species formerly known as Echinorhynchus anatis

Schrank, of which he considered E. filicollis, Rud., E. polymorphus

Bremser, and E. levis vonLinst. as synonyms. In this species,

F. anatis (Schr.), the female has a peculiarly modified proboscis

at the end of a slender neck. Only a portion of the surface of the

large inflated proboscis carries hooks. This characteristic was in-

corporated into Liihe’s definition of the genus. Regarding the de-

velopment of the proboscis in Echinorhynchus filicollis Rud., which

as indicated above Liihe accepted as a synonym for Folicollis anatis,

de Marval’ (1905 :267) has given a complete account of the changes

in form accompanying advance in age of the female. His figures

103, 104, and 106 indicate in the development of the female a grad-

ual change from an ovoid proboscis slightly larger than the neck

in very young forms to the inflated, spherical form characteristic

of the fully mature female. These three figures have been copied

by the writer in the present article as figures 1, 2, and 3. In order

to evaluate this point of structure fairly it should be borne in mind

that these changes in the form of the proboscis occur after the

individual has found lodging in the final host. To the writer it

seems within the bounds of reason that such a characteristic as

the shape of the proboscis appearing near the end of the develop-

ment of the individual carries with it but slight phylogenetic sig-

nificance. Consequently it could signify nothing more than a spe-

cific character and no longer should be considered as diagnostic

for the genus.

The writer has found individuals belonging to a new species

which agree in all essential details with the description of the genus

Filicollis except in the lack of this inflated proboscis of the female.

The creation of a new genus for such a minor variation would ne-

cessitate the separation of forms which are evidently closely related.

*Contributions from the Zoological Laboratory of the University of Illinois, No. 63.

j 116 pp M. 1911. Die Siisswasserfauna Deutschlands, Heft 16, eons

ena; p-

rval, L. de 1905. Monographie des acanthocéphales d’ 7

Ee ea ps pee see p n phales d’oiseaux. Rev. suisse

Ry H. J. VAN CLEAVE

To avoid this confusion the description of the genus should be

modified so that the species F. botulus, described later in this article,

may be included within its limits. In view of the fact that this

adds but one more species to the genus the writer does not feel

justified in offering a complete emendation of Liihe’s definition but

offers as a suggestion that until more is known of members of this

genus the original definition (Lithe 1911:30) should be qualified

by adding the statement: “The proboscis of the female may be

dilated, or in some species the proboscis of the female may assume

the same form as that described for the males of the genus.”

Filicollis botulus n. sp.

Description. Body both sexes cylindrical, large, thick, sausage

shape; about 20 mm. long; about 4 mm. in diameter. Neck long,

naked, retractable; 0.76 mm. long; 0.38 mm. diameter at posterior

end. Proboscis sheath 2 mm. long. Body of male spined short

distance back from neck, spines about 0.012 mm. long. Mature

female with no distinct spines in this region, cuticula of anterior

part of body in minute elevations. Proboscis ovoid, 0.65 mm. long,

0.57 mm. in diameter, armed with sixteen longitudinal rows of

seven or eight hooks each. Hooks practically uniform in size,

basal hooks 0.060 to 0.062 mm. long, apical hooks slender, basal

hooks without distinct roots. Embryos elliptical, with three con-

centric membranes; 0.071 to 0.083 mm. long, 0.030 mm. broad.

Type host Somateria dresseri, in intestine. Type locality Maine,

U. S. A. Cotypes in collection of Bureau of Animal Industry,

Washington, D. C., catalog number 2080; and in collection of the

writer at Urbana, Illinois.

The material upon which this specific description is based was

collected by Mr. Albert Hassall in Maine during the month of April,

1892. There are fifty specimens in the collection examined by the

writer. In addition to this material the collections of the Bureau

of Animal Industry contain several hundred specimens of this

species from the type host and from S. mollissima |S. m. borealis? |

Acanthocephala of this general form from American ducks

of various species frequently have been assigned by earlier workers

to the species ‘Echinorhynchus polymorphus. The confusion of

FILICOLLIS BOTULUS N. SP. 133

the species E. polymorphus Bremser, E. anatis Schrank, and E.

filicollis Rudolphi of the early workers has been very general. After

various investigators had attempted to solve the problem of the

relationships of these species Liithe (1911; 27 and 30) has finally

made a careful analysis of the characteristics of these species

through which he was led to establish two independent genera,

Filicollis and Polymorphus. The addition of another species to

the genus Filicollis furnishes support to the contention for the

validity of this genus, which is very clearly a natural group in the

classification of the Acanthocephala.

134 H. J. VAN CLEAVE

EXPLANATION OF FIGURES

All original figures were drawn with the aid of a camera lucida. A

projected scale indicating the magnification accompanies each drawing.

Fig. 1. Filicollis anatis, fully mature female redrawn from deMarval 1905,

fig. 103.

Fig. 2. F. anatis, young form. Redrawn from deMarval 1905; fig. 104.

Fig. F. anatis, very young form. Redrawn from deMarval 1905; fig. 106.

Fig. 4. F. botulus n. sp., male. Neck retracted. Body spines not shown.

Arrow indicates posterior limit of spined region.

»

Fig. 5. Cuticular body spines from anterior region of body of male shown f

in fig. 4.

Fig. 6. F. botulus n. sp., female. Tip of proboscis slightly inturned.

Fig. 7. F. botulus. Proboscis and part of neck of female.

Fig. 8. Profile, ventral surface, of proboscis shown in fig. 7.

Fig. 9. F. botulus. Embryos from body cavity of female.

oO.2mMm

Pirate XVIII

outed

‘9

DEPARTMENT OF NOTES. REVIEWS, ETC.

It is the purpose, in this department, to present from time to time brief original

notes, both of methods of work and of results, by members of the Society. All

members are invited to submit such items. In the absence of these there will be given a

few brief abstracts of recent work of more general interest to students and teachers.

There will be no attempt to make these abstracts exhaustive. They will illustrate progres.

without attempting to define it, and will thus give to the teacher current illustrations, and

to the isolated suggestions of suitable fields of investigation.—[Editor.]

NOTES ON HANDLING PROTOZOA IN PURE LINE WORK

During the past year the writer has been engaged in experi-

ments on the inheritance of extra contractile vacuoles in a new

race of Paramcecium and has worked out some methods of tech-

nique that have so facilitated his work that he is led to publish them

in hope that they may be of benefit to others.

Maintaining pure cultures—The greatest care is necessary to

prevent pure line cultures from becoming mixed with others. Even

with labelled pipettes accidents may occur. The scheme shown in

Fic. 1 Fic, 2

the cut was recently devised and has proved most convenient. A

piece of soft brass wire is shaped about some round object of a

diameter slightly larger than a pipette and is held by several twists.

Then the long ends of the wire are bent around the culture jar

and again fastened by twisting the ends. In the jars used by the

writer (humidors bought at any five and ten cent store) there is

a convenient groove near the top into which the wire fits nicely.

When finished the small circle protrudes from the jar and into

136 NOTES, REVIEWS, ETC.

this ring the pipette is dropped giving the appearance of Fig. 1.

With this method pipettes are always at hand and there is no dan-

ger of mixing the lines by transfering animals (clinging to the wails

of a pipette) from one culture to another. ;

Preparation of watch glasses——Syracuse watch glasses have

been used for single individuals throughout the writer’s work and

considerable difficulty was experienced at first in locating animals

which were close to the edge of the container. They frequently

found their way there as the fluid had a tendency to spread evenly

over the surface of the watch glass. Several methods were tried

to correct this tendency of the culture medium to spread over the

bottom but the best one was hit upon accidentally. There was a

trace of paraffin in a pan in which the glasses were being sterilized

one day and this coated the glasses imperciptibly but sufficiently to

give the liquid no hold on the glass. In vessels treated in this way

the surface tension of the medium tends to draw it into a spherical

mass. Should the liquid roll to the edge of the glass where the

animals would be hidden from view, it is easily rolled out again by

tilting the glass and none of the animals in the drop are left be-

hind. When animals are being kept in very small drops of water

the writer has placed as many as twenty individual drops of liquid

containing protozoa in a single watch glass and they have not run

together. The surface tension of the liquid draws it up, when

on a paraffined surface, until it gives a very fair picture of a drop

of mercury. Furthermore, being contracted to the smallest area

possible there is less evaporation than when the same amount of

fluid is spread out and the chances of losing a valuable specimen

through drying are very much less. The writer’s practice is to

use a piece of paraffin about the size of a pea to a quart of water.

This will be sufficient for a surprising number of watch glasses.

When the sterilized glasses are removed they are wiped while hot

and polished. No paraffin is visible although a faint trace of it

can be felt.

Making Pipettes—In this work the most useful pipette has

been found to be one that has a short but very fine tip. The usual

methods of drawing them tend to make a pipette with a rather

long tip as the glass tube has been heated for some distance

AMERICAN MICROSCOPICAL SOCIETY L3/

equally along its length. To cut down the area heated the tube to

be drawn is placed transversely across a fish tail flame, which heats

equally an area certainly not more than a quarter of an inch at

found their way there as the fluid had a tendency to spread evenly

the most, and the tube is pulled with considerable force when the

glass is just commencing to melt. Several trials will show the best

time to start pulling. This method gives pipettes with very fine tips

not more than from three-quarters to one and one-half inches long.

Zoological Laboratory, Rorert T. HANCE.

University of Pennsylvania.

NOTES ON EMBEDDING IN PARAFFIN

When embedding very small objects, such as insect larve or

small flowers or anthers, in paraffin it is most convenient to orient

them one behind the other. This method allows a single block to

be made of from three or four to a dozen pieces of tissue and these

may be cut in one ribbon. This obviously eliminates a great deal

of the labor involved in making a block of each separate object,

cementing it to the holder, trimming it and adjusting the microtome

each time. In the ribbon it is easy to see where one piece of tissue

ends and the other begins as there is usually several blank sections

of paraffin between them. It is relatively simple to arrange the

tissue in line under a carbon bulb with warm needles but a diffi-

culty is met with when an attempt is made to place the paraffin

mold in water for cooling. The material is shaken from position

and must be reoriented. This had been overcome in the following

way. A watch glass is used as a mold for embedding small ob-

jects and a petri dish is convenient for larger tissue. When the

tissue is ready to be embedded the dish is heated to the melting

point of the paraffin under the electric bulb. It is then placed in a

crystallization dish with two slides beneath it to prevent it from

touching the bottom of the container. Paraffin is then poured into

the small dish and the objects oriented as desired the heat of the

electric bulb keeping the paraffin melted. Then the light is turned

off and cold water is poured into the crystallization dish. Since

the dish containing the paraffin is raised from the bottom the water

flows under it and soon solidifies the paraffin in the lower part of

,

138 NOTES, REVIEWS, ETC.

the dish which consequently holds the objects fast. As soon as

a surface film is formed enough water can be added to cover the

embedding mold to complete the hardening of the paraffin.

In petri dishes or watch glasses the bottom is practically flat

and true and the tissue is allowed to sink to the bottom. When

the tissue is cut out as a block the part that rested against the

bottom makes one of the two parallel sides and requires little or

no trimming.

When a number of pieces of tissue or a number of series (as

described above) are embedded in one disk of paraffin it is dan-

gerous to attempt to separate them with a knife as one can never

be sure of the direction the crack in the paraffin will take. I have

found that a hand scroll saw or coping saw (which may be pur-

chased for ten to twenty-five cents) does admirably for cutting

a block of tissue from the main disk. A hot wire is used by some

but is not nearly so convenient nor so accurate as the saw. The

use of the saw permits many more pieces to be placed in the same

space as no care need be taken to have well defined pathways for

the paraffin to split along as is necessary when a knife is used for

i he pi :

separating the pieces Rosert T. HANcE.

A NEW SPECIES OF OPERCULARIA

Opercularia wallgreni Grier n. sp.

Plate XIX. Figs. 1 and 2

Bodies ovate or attenuate fusiform, about 3 times as long as

broad, tapering mostly toward the pedicle extremity. Ciliary disc

never elevated above the margin of the peristome a greater dis

tance than % the length of the animal, apparently with but one

circlet of cilia. Membranous collar moderately large, but obliquely

set. Endoplast band-like, curved, parenchyma beneath granulated.

Pedicle tree-like, slender, branching profusely and dichotomously,

attaining a considerable proportionate altitude, delicately striate

in a longitudinal direction. Transverse articulations wanting or

present only where branching occurs.

Height entire polypidum 1.4 mm., length extended sooid .10

mm., width .022 mm., width of pedicle .00o5 mm.

PrAmE lex

AMERICAN MICROSCOPICAL SOCIETY 139

Habitat—Fresh water, apparently only upon aquatic plants.

The colonies may include from 2 to about 200 zooids, which assume

a nodding or pendant position after contracting. The species de-

scribed was found in an aquarium in the writer’s laboratory at the

Central High School, first growing upon Sagittaria platyphylla

Smith, but readily attaching itself to Elodea, Myriophyllum, and

other aquatic plants. Its food consists for the most part of uni-

cellular Algz although Protozoa were sometimes observed in pro-

cess of digestion. The species is very prolific, and while it does

not grow in a hay infusion, quickly covers the walls of aquaria,

growing thickest on the sides nearest the light. It is apparently

of great longevity. This form I have respectfully dedicated to

Dr. A. B. Wallgren, Professor of Zoology, University of Pittsburgh.

EXPLANATION OF FIGURES

PL. XIX.

Fig. 1. Entire colony x about 90.

a, b, c, d. Successive positions assumed by zooids during acquisi-

tion of food.

e. Curious introverted position noted.

Fig. 2. Two zooids x about 400.

f. Expanded, taking in food.

g. Contracted.

h. Attached bacterial growth.

Central High School, N. M. Grier.

St. Louis, Mo.

A METHOD OF MAKING TOTO MOUNTS OF UNICELLULAR FORMS

The matter of making toto mounts of unicellular forms often

presents considerable difficulty. The cells or ccenobia settle so

slowly that there is danger of losing them in the changes of liquid,

and this slowness in settling makes the use of the more precise

stains difficult. A method which has been successfully used for

small forms like Scenedesmus is described in Chamberlain’s “Meth-

ods in Plant Histology,” University of Chicago Press, 1915. It

consists of drying the cells down on the slide and then carrying

them through all subsequent processes on the slide as in the case

of paraffin sections. This method seems to cause some distortion

,

140 NOTES, REVIEWS, ETC.

even in the smaller forms and a large form like Closterium is

ruined. The following method, discovered in the botanical labo-

ratories at the University of Nebraska, has been found to combine

the good fixation and preservation of the bulk method with the

Precision of staining and the ease of handling secured by drying

the cells to the slide.

The material is killed and fixed in whatever solution the in-

vestigator has found most satisfactory for the particular group of

algze or Protozoa with which he is working. It is washed in bulk

in the usual manner and carried through a graded series of alco-

hols until a strength of about sixty per cent. is reached. It is

allowed to settle completely in this grade. A very thin layer of

albumen fixative is smeared upon the thoroughly cleaned slides. A

drop of the material is then drawn up with a pipette and placed

upon the slide. The sixty per cent. alcohol in which it is lying

coagulates the albumen and causes a surprisingly large number

of cells to be firmly fixed to the slide. They may now be dipped

directly into sixty per cent. alcohol and successively into higher

grades. It is possible to use such stains as Flemming’s triple and

iron-alum hzematoxlin rapidly and with precision. Before using

a stain like Flemming’s triple it is usually well to harden the cells

thoroughly in ninety-five per cent alcohol, and then proceed as

usual.

Univ. of Nebraska. Ropert A. NEspit,

METHOD TO CLEAN USED MICROSCOPIC SLIDES

Especially where a course is given in microscopic technic

there are usually a large number of worthless slides prepared. To

throw them away seems an extravagance and yet to clean them

in waste-xylol is practically a waste of time.

The method I am about to suggest may be well known, yet

I think it will bear repeating. There had been a large number of

old slides collecting from year to year in our department, worth-

less and merely occupying space, yet no one cared to assume the

responsibility of throwing them away. Recently Professor Reese

head of the department, suggested we try gold dust in an attempt

to clean them.

AMERICAN MICROSCOPICAL SOCIETY 141

A liberal amount of gold dust and a number of the slides,

some of them dated 1902, were placed in water, and thoroughly

boiled. As soon as the cover slips came off of their own accord,

the slides and slips were placed in a pan of water. These were

wiped dry while others were being boiled. The ease with which

they can be cleaned and dried and the small amount of time re-

quired compared to the waste-xylol method, makes it a very profit-

able undertaking.

On taking them from the gold dust solution they were first

placed in waste alcohol, but it was found by placing them in water

they could be cleaned and dried much easier.

Zoological Laboratory, J. THEron ILrick.

West Virginia University.

ENTOMOLOGICAL NOTES

Chromosomes of Notonecta—Browne (716, Journ. Morph.,

27 :119-162) has made a comparative study of the chromosomes of

five North American species of Notonecta (undulata, irrorata, in-

sulata, shooteru, and indica) and one species of the same genus

from Europe (glauca). Among other things, it was found that

an XY pair of chromosomes is present in each of the above-men-

tioned species, the components of which divide separately in the

first division and go to the opposite poles in the second. The X

and Y chromosomes vary in size in the cells of the different species

as well as in the cells of different individuals of the same species.

They are almost equal in most of the cells of certain individuals

of shooteru, while in indica they are distinctly unequal. Undulata,

indica, and shooteri have 14 chromosomes in the first division, 13

in the second, and 26 in the diploid groups. Jrrorata and glauca

have 13 chromosomes in the first division, 12 in the second, and

24 in the diploid groups. Jmusulata has 14 or 13 chromosomes in

the first division and 12 in the second. Large double chromosomes

occur in insulata, glauca, and indica. No definite correlation of

the somatic characters of the different species with the difference

in chromosomes number and arrangement was discovered, although

it was found that the 14-chromosome species are the smaller and

the 13-chromosome ones are the larger. It thus appears that while,

,

142 NOTES, REVIEWS, ETC.

in general, a definite number and arrangement of the chromosomes

of each species exist, the status of each species in relation to the

others cannot at present be determined on this basis. The chromo-

somes and somatic characters seem to indicate that indica has

been derived from undulata.

Mitochondria.—Lewis and Robertson (716, Biol. Bull., 30:99-

124) studied, by the tissue culture method, the mitochondria and

certain other structures in the male cells of the grasshopper Chorth-

ippus curtipennis. By using a culture medium which very closely

approached Locke’s solution, it was found that, in addition to the

fact that the minute structures of the living cells could be exam-

ined from day to day, these structures could be experimented upon

as readily as those of the chick embryo. Any stage in the develop-

ment of the germ cell was obtained by this method and was studied

in the stained and unstained conditions, the staining being done

with Janus green and neutral red. By these methods, mitochondria

and neutral red granules were demonstrated in the primary sper-

matogonium. The former are present in the primary spermatogonium

as small, delicate granules and increase in quantity during the

growth stage, becoming definitely arranged along the spindle dur-

ing the spermatocyte division. In the spermatid, they form the

nebenkern, later developing “into two equal homogeneous threads

in the tail of the spermatozoon.”

Gynandromorphism.—Cockayne (’15, Journ. Genetics, 5:75-

131), in a paper entitled “Gynandromorphism and Kindred Prob-

lems’, presents a comprehensive discussion of gynandromorphism

among animals, the greater part of the data being drawn from

insects. Descriptions of a number of new examples are presented.

The data included in the paper are not readily summarized and

cannot be included here. A somewhat elaborate and suggestive

classification of “hermaphrodites” is given. The theoretical ex-

planations of gynandromorphism are taken up in some detail and

considered critically. A number of text figures illustrate the con-

dition of the internal reproductive organs in some of these anam-

alous insects. Four plates devoted exclusively to Lepidoptera illus-

trate certain forms of gynandromorphs. A bibliography of sixty-

eight titles accompanies the paper.

AMERICAN MICROSCOPICAL SOCIETY 143

Color Changes in Dynastes——Andrews (’16, Journ. Exp. Zool.,

20 :435-456) reports results of studies on color changes in adults

of the rhinoceros beetle, Dynastes tityrus. It was discovered that

when live specimens of either sex which were light yellow with

dark spots were confined for a time in receptacles with wet de-

cayed wood, they all became very dark reddish with the spots

scarcely visible. When removed from these conditions, they rap-

idly returned to the usual light coloration. Since such changes in

an animal having no changeable pigment cells or blood vessels so

distributed as to make color change possible seemed to be unre-

corded, experiments were undertaken to determine the nature of

this phenomenon. Variations in moisture were found to underlie

the conditions which produced the color changes. These color

differences can be explained without the assumption of internal

nervous activity since, in general, the reactions of a dead, dried

specimen were the same as those of the living beetle in all respects

concerning the change of color from light to dark and the re-

verse. Experiments with light, heat, and moisture yielded results

which made it evident that both living and dead beetles behaved

alike in changing color under conditions which were interpreted

as chiefly involving differences in the amount of water presented

to the surfaces of the elytra and the thorax. Results of experi-

ments pointed to the conclusion that any liquid which can enter

the shell may cause it to change from light to dark color. Micro-

scopical examination of the elytron showed that it is composed

of an outermost layer of such a nature that it readily absorbs and

gives off moisture. The absorption of liquids permits the color

of the underlying part of the exoskeleton to appear as dark red,

whereas when air replaces the moisture in this layer, it prevents

the underlying color from showing through. The dark spots which

do not change appear to be due to the presence of some material

which so fills the pores or interstices that it acts as if it makes the

area permanently wet or to some degree soaked with liquid, thus

rendering visible the underlying color. The relation of these color

changes to the life activities of the insects is not known.

Light Reactions of Vanessa antiopa—Dolley (’16, Journ.

Exp. Zool., 20:356-420) finds that Vanessa antiopa is invariably

144 NOTES, REVIEWS, ETC.

positively phototactic and in direct sunlight comes to rest with the

head away from the source of light. Specimens with one eye

blackened and placed face foremost in a horizontal beam usually

turn toward the functional eye, occasionally continuing to turn in

this fashion, thus performing circus movements, but usually re-

versing the movement at the edge of the beam and moving toward

the source of light. In non-directive light, the insects perform

circus movements only, each turning toward the functional eye.

Apparently, the stronger the light the larger are the circles described

by the insect. Non-directive light of very low intensity does not

deflect either way specimens with one functional eye but a further

reduction of this light leads to the performance of circus movements

toward the blinded eye. The behavior becomes modified by re-

peated trials, the modification being manifested in three ways: (1)

decrease in number of circus movements; (2) decrease in angle of

deflection; and (3) increase in promptness of orientation at edge

of beam. With one eye blackened, this insect, when moving to-

ward a source of light, can re-orient when the direction of the

rays is changed and always in such a way as to turn toward the

source of light. In darkness, blinded specimens move in circles

toward the blinded eyes, showing that the covering acts as a stim-

ulus. In light, blinded specimens circle in the opposite direction,

showing that light received by the functional eyes is the stimulus.

Evidence indicates that the reaction may depend upon the localiza-

tion of photic changes within the eyes and that orientation is not

wholly dependent upon the relative intensity of light on the func-

tional and blinded eyes.

Origin of Wings—Crampton (’16, Journ. N. Y. Ent. Soc.,

24 :1-39) presents a thoroughgoing summary and critical examina-

tion of the various theories relating to the origin of wings in in-

sects. Special attention is given to a comparison of the evidences

advanced in support of the tracheal gill theory and the paranotal

theory of the origin of insect wings. The latter is favored and

some original data are offered in its support. The wings of all

insects are regarded as homologous and of common origin, thus

being subject to the same principles regardless of the kind of meta-

morphosis. Tracheal gills and wings have been shown by em-

AMERICAN MICROSCOPICAL SOCIETY 145

bryological studies to belong to different developmental series and

are not homologous, facts which offer very strong counter-evidence

against the derivation of wings from tracheal gills. Since the par-

anota (integumental outgrowths on the sides of the tergum) are

homodynamous with the wings, the latter “were doubtless derived

from them, since they occur in the most diverse forms”. The only

reliable evidence available at present is that of embryology, such

evidence indicating that the wings are of tergal origin. It is also

concluded that the paranota from which the wings are thought to

have originally developed were entirely or in part expansions of

the tergum. A bibliography of two hundred twenty-two titles

accompanies the paper.

Wing Venation of Hymenoptera.—Rohwer and Gahan (’16,

Proc. Ent. Soc. Wash., 18:20-72) have published a paper on the

‘“Horismology of the Hymenopterous Wing” in which a modified

form of the old Cresson system of wing venation terminology is

proposed. The paper is valuable because of the extensive synonymy

and comparisons of the systems used in the past, thus making

much easier the translation of one system into another and the

determination of equivalent names. The new system which is

proposed is based on the opinion of the writers that “it is better

for taxonomatic work to designate a given area by a given name and

call it that regardless of its possible homologies or analogies.”

The new system is constructed only for insects of the order Hy-

menoptera and is apparently a revival of the old custom of using

different systems of terminology for venation in the different orders

and of using purely arbitrary systems rather than those based on

homology. The writers point out what they consider to be ob-

jections to the Comstock-Needham system but there is doubt that

these objections are well taken. Unfortunately, such a system as

the one proposed in this paper, in spite of its possible commendable

points, will have the effect, if adopted at all extensively, of im-

peding the development of a common system, based upon homologies,

for all of the orders of insects, a system much to be desired.

Parasites ——Timberlake (’16, Can. Ent., 48:89-91) finds that

certain insects (beetles) may be parasitized by Dinocampus ameri-

canus, a common braconid parasite, without producing the death

146 NOTES, REVIEWS, ETC.

of the host. It was observed that certain individuals of Hippo-

damia convergens, Coccinella 9-notata, and Olla abdominalis might

be parasitized, the larva attain full growth and escape, and the

recovery of the host be apparently complete. Experiments in which

individuals of Hippodamia convergens and Olla abdominalis were

exposed to the parasite showed that this particular parasite does

not injure the vital organs of the host, although its fatty lymph

tissues are often left in such a depleted condition that the beetle

soon dies. The exit aperture of the parasites is itself sometimes

fatal in effect. These experiments showed that successive para-

sitism may occur, resulting in the emergence of more than one

generation of the parasite from the same host.

Insects and Fire Blight-—Stewart and Leonard (716, Phyto-

pathology, 6:152-158) report the results of experimental studies

on the role of insects in the dissemination of fire blight bacteria.

Experiments with certain Diptera (Pollenia rudis and Sapromyza

bispina) seem to indicate they they are not active agents in increasing

the number of twig blight infections, since their method of

feeding is such that it is doubtful if the blight bacteria which

they may carry can gain entrance to the tissues. Possibly the

bacteria carried by the flies may gain entrance through the punctures

of other insects and produce a few infections. Flies are thought

to be most important in those cases where they carry the causal

organism to blossoms and occasionally to wounds, such as those

produced by hail stones. The authors believe that all of the suck-

ing bugs in nurseries are important in this connection. The num-

bers, methods of feeding, and seasonal distribution make the

various species of different interest and importance in the trans-

mission of blight bacteria. It is suspected that those which feed

upon the tender tips of the twigs are of more importance than

those which feed upon other parts of the foliage. Lygus invitus,

Heterocordylus malinus and Lygidea mendax are of importance in

spreading fruit blight in orchard trees.

Embryology of Honey-bee.—Nelson (’15, Princeton Univ.

Press) has recently published a book on “The Embryology of the

Honey Bee”, which is the most comprehensive and thoroughgoing

treatise that has yet appeared on this subject. The author has been

AMERICAN MICROSCOPICAL SOCIETY 147

concerned not only with the details of the development of the

honey-bee but he has employed the comparative method of treat-

ment, drawing extensively upon the works of other investigators

on the embryology of insects in general, thus making the book

valuable in connection with any work in insect embryology. The

large mass of data cannot be summarized here but certain special

features deserve mention. The duration and rate of development

were specially considered and it was found that the total time

normally required for embryonic development is 76 hours. This

period is divided into stages I-XV. Cleavage requires 14-16 hours;

formation of blastoderm, 14-16 hours; formation of mesoderm,

rudiments of mesenteron and embryonic envelope, 12-14 hours;

remainder of development, including differentiation of tissues and

organs, 32-34 hours. Discussion of the formation of the mesen-

teron is accompanied by an extensive comparison of the various

opposing views and interpretations of other investigators on this

subject. The different writers are classed according to the follow-

ing theories of mesenteron origin: (1) derivation from yolk cells;

(2) derivation from the lower layer (mesoderm, entomesoderm,

primary entoderm); (3) derivation from proliferations of the

blind inner ends of the stomodzal and proctodzal invaginations ;

(4) derivation, independent of the mesoderm, from two proliferat-

ing areas of the blastoderm, one at each end of the germ band,

corresponding to the future location of the stomodeum and

proctodeum, respectively; and (5) derivation from cells migrating

inward from thickenings or islands of the blastoderm. Nelson

holds that “the relation of the mesenteron rudiments in the honey

bee may be interpreted in two ways, and the one chosen will

probably depend largely on the theoretical bias of the interpreter.

First, the mesenteron rudiments may be referred to the mesoderm

ee Second, the mesenteron rudiments may be considered,

LS ee as purely blastodermal in origin.” A final decision

between these two interpretations is not attempted. Segmentation

is considered rather fully and is found to be as follows: head,

six segments; thorax, three segments; and abdomen, twelve seg-

ments. Appendages were observed on the antennal, the three

gnathal, and the three thoracic segments. There is evidence that

in the honey-bee the tritocerebral (intercalary) segment should be

,

148 NOTES, REVIEWS, ETC.

considered as “exaggerated ganglionic swellings” which probably

do not represent appendages. Nelson has found nothing which

could be “safely construed as abdominal appendages”. Degenerat-

ing cells of unknown significance occur in the rudiments of the

brain, particularly in the region between the second and third lobes

of the protocerebrum. The tracheal system is formed from eleven

pairs of invaginations of the lateral ectoderm, one pair, which seems

to be observed for the first time, occurring on the second maxillary

segment. This discovery is significant since “Now that a pair of

tracheal sacs is known to exist in the second maxillary segment,

the homology of the second pair of tentorial invaginations with the

stigmata of the second maxillary segment is completely excluded,

and the homology of similar invaginations with those of the trachea

is decidedly problematical”. The tentorium develops from two

pairs of ectodermal invaginations, one in front of the bases of the

mandibles and the other behind the bases of the first maxilla. The

cenocytes develop from the migration of cells from eight pairs of

localized areas of the lateral ectoderm which occur on the first

eight abdominal segments at the same level as the tracheal in-

vaginations. The mesoderm differentiates laterally into a somatic

and a splanchnic layer, the mid-ventral region remaining single

layered. Separate coelomic sacs are wanting. The single layered

area develops into the rounded blood cells; the somatic layer forms

the trunk muscles, the pericardial fat cells, and the dorsal dia-

phragm; and the splanchnic layer gives rise to the muscle layer

of the mid-intestine and the two main divisions of the fat body.

A mid-dorsal union of two rows of cardioblasts, derived from the

two mesodermal layers, forms the heart. Two masses of meso-

dermal cells, one forming the anterior and one the posterior end

of the mesoderm, produce the muscle layer of the stomodeum and

the proctodeum respectively. One hundred fifty-seven titles are in-

cluded in the bibliography at the end of the book.

Kansas State Agricultural College. Paut S. WELcH.

NOTES ON OLIGOCHETA

Galvanic Response of Earthworm.—Moore and Kellogg (’16,

Biol. Bull., 30:131-134) have tested the galvanic reaction of

AMERICAN MICROSCOPICAL SOCIETY 149

Lumbricus terrestris to constant current. Orientation began as

soon as the current was submitted and the body of the animal took

the form of a U with the concave side toward the kathode.

Writhing movements accompanied this orientation and as a rule

the animal ultimately crawled to the kathode. Pieces of the body

of the worm, 3-4 cm. long, subjected to the constant current,

responded in the same way, except that progressive movements were

absent. Reversal of the current produced a reversal of the response.

The reactions are interpreted as due to the tension of the longi-

tudinal muscles on the kathode side of the worm, resulting in a

stronger contraction than that which occurs in the anodal region.

South Indian Oligocheta.—Stephenson (’15, Memoirs of the

Indian Museum, 6:35-108) reports results of studies on Oligocheta

of Ceylon and Southern India. The eversible pharynx of certain

enchytreids was studied and a sensory function is suggested for

this organ. The constant presence of sete within the cclom of

Fridericia carmicheali, surrounded by masses of lymphocytes, is

discussed and the tentative explanation is that they are formed,

not as are the sete of the body-wall, but as excretory products which

take the form of rods or spicules, persisting in the body-cavity

or disintegrating and being eliminated through the usual channels.

The so-called iridescent sperm funnels of some earthworms have

been found to be due, not to iridescence of the funnel itself, but

to the spermatozoa which are so disposed that they form innumerable

extremely fine threads lying parallel and which function as a

“diffraction grating’. New species of the genera Enchytreus,

Fridericia, Drawida, Pontodrilus, Megascolides, Comarodrilus,

Perionyx, Megascolex, and Erythreodrilus are described.

Regeneration—Hyman (’16, Journ. Exp. Zool., 20:99-163)

has studied regeneration in a number of species of Oligocheta be-

longing to the families Aeolosomatide, Naidide, Lumbriculide, and

Tubificide. By the use of Child’s cyanide method, a gradient in

the rate of metabolism of two forms, primary and secondary, was

demonstrated. In the former, the rate of metabolism decreases

posteriorly from the head and was found only in Aeolosoma and

the zooids of Naidide, while the latter is superimposed upon the

primary gradient but runs in the reverse direction. The secondary

150 NOTES, REVIEWS, ETC.

gradient involves the caudal third of the body in Dero limosa, the

caudal half or more in Lumbriculus inconstans, and all but the

first 5-15 somites in the Tubificide. Only the typical number of

head somites are regenerated following amputation of varying

numbers of anterior somites. The head regenerates a tail only

when accompanied by a certain number of trunk somites and the

tail regenerates a head only when it is of a certain minimum size

whereby the gradient is eliminated. Under these conditions, re-

gardless of length, a piece of Dero limosa regenerates a normal

worm. If of appropriate length, any part of the body of Lum-

briculus inconstans regenerates a normal worm, normal posterior

regeneration occurring at any level. Formation of the head in

Tubifex ceases at about the level of the fifteenth somite, while in

Limnodrilus it ceases at the level of the seventh somite. The

gradient of an axial series of pieces is not the same as that of the

whole worm since temporary stimulation results from the cutting.

Rate of metabolism is an important factor in anterior regeneration

in short pieces since head formation will be inhibited in proportion

to the metabolic rate of the old piece. If this rate be low, no

inhibition of the new tissue occurs and a normal head is produced.

Normal heads are always formed on long pieces since the dynamic

factors are not important and the primary gradient determines the

increased independence of cells at an anterior level over those of

a more posterior level. 1

, Pau S. WELcH.

Kansas State Agricultural College.

NOTES ON THE COLLECTION AND REARING OF VOLVOX

Since the rearing of Volvox for laboratory use seems to be

more or less unusual the writer has deemed it worth while to present

here the results of some work done by a class of students and

himself along this line.

Colonies of Volvox aureus Ehrenberg were found last fall in

some abundance in small sphagnum pools on the west shore of a

small glacial lake west of Ann Arbor known as the First Sister

Lake. Collections were made on October 27, 1915. Small water-

filled depressions in the sphagnum 10 to 30 inches in diameter were

AMERICAN MICROSCOPICAL SOCIETY 151

sought out and into these depressions pint jars were thrust in such

a way as to secure some bits of sphagnum and decaying vegetable

matter together with water. The contents of the jars were sedi-

mented and the liquid just above the sediment examined for

colonies. When found the water at the top was poured off since

the organisms were settling to the bottom and the remaining water

and sediment from several jars poured together. Examination of

many small pools on the shore of this lake showed that Volvox

was not present in many of them. Some pools yielded Pleodorina.

No colonies were found in the water of the lake itself.

Smith (1907) who has collected Volvox in the vicinity of Ann

Arbor has found it in “small glacial pools containing Riccia and

duckweed” but apparently had not found it among sphagnum.

He (Smith, 1905) found it best in permanent pools but apparently

never in great abundance. He collected it by “dipping it up together

with a little of the water” and also “by sweeping a bolting cloth net

over water plants, or better, using a ‘Birge net’”’. Smith’s method

of dipping up the water together with plant material has been found

by me to be the best method for collecting the organism here in

Michigan. While in Nebraska the writer found V. perglobator

Powers in such great abundance and in such clean open water that

it was best collected with a small dipnet covered with bolting cloth

or India linen. In this way large quantities of water could be

passed through the net in a short time.

The collections made on October 27, 1915, were brought to

the laboratory in the pint jars filled almost to the top with the

water in which the organisms grew, together with about a half inch

of the decaying vegetable material from the same source. Arrived

at the laboratory these jars, still covered, were placed on the outside

window ledge on the north side of the laboratory where no direct

sunlight could strike them. They were kept here until November

29 when ice began to form on the surface of the cultures. At this

time all jars except three belonging to the writer were brought

inside the building. The writer’s cultures remained outside for

some time longer. While outside the window the number of colonies

had increased greatly but when brought inside the numbers steadily

diminished and soon disappeared. One student, Miss Rose Mayer,

152 NOTES, REVIEWS, ETC.

placed her cultures in an unheated room, not in direct sunlight,

where they continued to thrive for some time. An abstract from

her report on her cultures is here given:

1915.

Oct. 27. Volvox collected. (Other data as given above.)

Oct. 28. Jars containing Volvox were placed outside of the window on

the north side of the building.

Nov. 3. Volvox was multiplying.

Nov. 15. Still increasing in number.

Nov. 29. Cold outdoors, some ice on surface of water. As many colonies

as could be gathered were preserved. The remainder were

placed in an unheated room but not in direct sunlight, i. e., the

windows (south) were covered with gauze to diffuse the light.

Dec. 13. A considerable increase had taken place. Another lot was re-

moved and fixed. Remainder was returned to the cold room.

Dec. 18. Colonies were quite numerous, but were beginning to fall to the

bottom of the jar.

Jan. 25. No colonies were observed. Since the last examination the tem-

perature of the room had increased considerably.

When the cultures belonging to seven other students were

brought inside they were so placed that they received some morn-

ing light. These cultures soon ran out and the writer has no

further record of them. The writer’s cultures (three pint jars)

remained on the window ledge on the north side of the building

until about December 5, but were protected at night with a cloth

thrown over them. When brought inside they were placed on the

window sill near the radiator. They received only north light.

The colonies gradually disappeared but no record was kept of

their last appearance. At various times the cultures were exam-

ined ocularly or with a hand lens but no colonies were seen until

February 19 when a few colonies were seen in one jar only. They

were noted again on February 26, and on March 7 the record states

that they were in fair abundance. On March 16 the estimated

number was 200 to 400 colonies and on March 27 several thousand

were seen. At the time of writing, April 27, the water is green

with them and they lie close together on the surface of the decaying

vegetation.

AMERICAN MICROSCOPICAL SOCIETY 153

During the fall and winter no colonies in sexual stages were

seen. On March 25 a single zygote was found in the debris from

the bottom of the culture. April 25 several colonies with ripe

zygotes were found but they were not numerous.

Of the other two cultures one was destroyed by accident about

the middle of March but no colonies had appeared in it at that

time. The other culture was observed from time to time and in

it 3 colonies were found March 20, about 20 on March 25, and

about 50 on March 27. April 20 there were several thousand

colonies present. These cultures are being kept in the hopes that

further information may be gained in regard to the culture of this

organism. .

In conclusion it should be stated that since these cultures were

not kept under controlled conditions it is possible that this success

could not be repeated. However, certain points in the culture of

this organism may be emphasized, viz., the water for the cultures

should be from the same source as the organisms. Never use tap-

water for making up the culture or for making good evaporation.

Keep the cultures covered to prevent evaporation and consequent

change in density of the medium and to exclude the dust and

bacteria. The presence of organic material seems to be beneficial.

Direct sunlight is unnecessary and is to be avoided because it causes

too great variations in temperature in closed vessels. North light

is good; in fact many alge thrive in it as evidenced by the good

growth of alge in these cultures. Low temperature, above freezing,

in early winter seemed to favor development. Old cultures should

not be destroyed unless they have become hopelessly foul but they

should be kept and the organisms given a chance to reappear.

BIBLIOGRAPHY

Kern, L.

1899. Morphologische und biologische Studien tiber die Gattung Volvox.

Jahrb. f. wiss. Bot., 20:131-210.

Meyer, A.

1896. Die Plasmaverbindungen und die Membranen von Volvox globator,

aureus, und tertius, mit Rticksicht auf die thierischen Zellen.

Bot. Zeit., 54:187-217.

154 NOTES, REVIEWS, ETC.

SmiTH, B. G.

1905. Collection and preparation of material for classes in elementary

Zodlogy. Amer. Naturalist, 39 :779-789.

1907. Volvox for laboratory use. Amer. Naturalist, 41 :31-34.

Zoological Laboratory, GeorcE R. La RUE.

University of Michigan.

A NEW EMBEDDING STAGE

A new electrically heated embedding stage prepared according

to designs prepared by laboratory men in this university has been

recently put on the market by Eberbach & Co. of Ann Arbor. The

essential parts of this embedding stage (see cut, Pl. XXI, Fig. 2)

are a transite base 1734 inches long by 4% inches wide mounted on

three levelling screws, a copper stage made in two parts, 4 by 13

inches and 4 by 4 inches respectively, and under one end of the

longer copper stage an electric heating unit. The heating unit may

be wound for any voltage and to yield any desired temperature.

Those in use in the Zoological Laboratory are designed for 110 v.

alternating or direct current and the current requirement is 0.5

ampere. This yields a temperature of about 74° C. No regulator

or rheostat or other provision for controlling or varying the tempera-

ture is provided but since the coil is situated under one end of the

stage lower temperatures may be secured by moving the object away

from coil. A scale to indicate the gradations of temperature could

be attached if desired. In practice the coil is attached to a convenient

electric receptacle near the paraffine bath and that part of the stage

over the coil is heated sufficiently to melt paraffine in a few minutes.

The embedding tray may now be warmed over the hot stage, filled

with melted paraffine and moved to a point on the stage where the

paraffine is kept just melted. Objects to be embedded are now

transferred to the embedding tray, oriented, and the label inserted

at the end of the tray with the legend towards the margin of the

tray. Now the tray is gently moved to the unheated end of the

stage where the paraffine is permitted to congeal on the bottoin

sufficiently to hold the objects in place. Then the tray is trans-

AMERICAN MICROSCOPICAL SOCIETY 155

ferred to a dish of cold water or alcohol standing at the end of

the embedding stage and into which it is immersed as soon as the

paraffine is cooled sentient to prevent the breaking of the surface

film by the water.

The use of this embedding stage makes unnecessary the use

of the top of the paraffine batk for this purpose. Its use helps

greatly in securing good embedding because it permits the paraffine

to be melted clear to the bottom of the embedding tray and thus

the orientation is made easy. The plan of allowing the object to

lie on a layer of congealed paraffine is not only unnecessary but is

faulty in that the paraffine is too soft to permit accurate orienta-

tion of the object and also because a cleavage plane is formed at

which the paraffine frequently breaks during the sectioning. The

stage is convenient to use, does away with the necessity of using

gas, and largely obviates the danger of overheating the tissue which

danger is always present when a gas flame is used for heating the

ordinary stage. This stage because of its low construction is very

stable, unlike the very insecure stage used with the gas flame, and

with the levelling screws it may be levelled. In several months’

use by a class no objectionable features have appeared and its good

points are only the better appreciated.

Zoological Laboratory, GeorcE R. La RUE.

University of Michigan.

MAKING GLASS PLATES FOR COVERING MUSEUM JARS

At this time when it is impossible to secure from abroad the

glass plates for covering museum jars it is worth while to know

that after a little practise passable plates may be made in any

laboratory equipped with power grinding and buffing machinery.

Double strength glass plates may be purchased cut to size or they

may be cut in the laboratory. Their edges may be rounded and

a narrow ground surface at the margin may be secured by grinding

on a carborundum wheel designated 120J-G5 which can be purchased

from the Carborundum Co., Niagara Falls. The size of the wheel

will depend somewhat on the power and speed of the grinder. In

this laboratory a 414 by % inch wheel belted to a %4 h. p. motor

156 NOTES, REVIEWS, ETC.

of about 1800 R. P. M. is used. While plates made in this way

are not as good as the imported article they are usable and cheap,

and by this means museum jars whose covers have been broken

may be put into use.

Zoological Laboratory, Georce R. La Rue.

University of Michigan.

THE POSSIBLE NATURE OF THE “BOOK LUNGS” OF SPIDERS

The abdomen of spiders is now unsegmented, and yet it is

probable that spiders have descended from ancestors whose bodies

were segmented throughout.

The breathing apparatus in spiders is varied, some forms show-

ing some development of tracheal tubes. On the forward end of

the abdomen are found two sacs, each of which encloses a folded

membrane which exposes the blood to the air. These are the

book lungs.

In the section of such a lung from an Aglena (Plate

XX, Fig. 1) the membranous character of the organ will be

seen. Red blood cells may be seen between the double mem-

branes. The outer surface of the membrane is covered with short

spines, which prevent the moist membranes from adhering.

It is possible that this arrangement is derived from an ances-

tral form which had external gills at this point, somewhat similar

to the tracheal gill membranes of insect nymphs.

A figure of a section of the young wing membranes of an

Ephemera nymph is shown (Pl. XX, Fig. 2) for comparison,

The similarity of structure is striking.

E. W. Roserts.

NOTE ON THE NATURE OF THE CYTO-PLASTID

The cyto-plasm of a cell contains unit plastids which them-

selves bear a great resemblance to a complete cell with its nucleus

and cyto-plasm.

Using the Tussock Moth egg for an illustration we get a

suggestion of this condition. The egg is filled with nutritive ma-

terial supplied by numerous nurse cells from their own cyto-

some system.

Fic. 1. Book-lung of Spider.

Fic. 2. Section of growing wing of Ephemerid Nymph.

PLATE XX

Nic. 2, Ilectrically heated embedding stage, Eberbach & Co.

PLATE XXI

AMERICAN MICROSCOPICAL SOCIETY 157

Into this mass of raw food material, are extruded from the

walls of the oviduct certain granules which stain as nucleo-somes.

These appear singly at first as seen at the edges of the photograph

(Plate XXI, Fig. 1). These chromatic bodies seem to multiply

by binary divisions and thus produce a progeny of various numbers

of staining bodies.

These bodies sometimes group themselves into paired threads,

and in some cases separate into distinct groups resembling the ana-

phase of nuclear mitosis. The cyto-plastids thus seem to act as

a miniature cell, containing grouped staining bodies, a surrounding

body of plasm, and a definite membrane.

These efforts of the staining bodies to divide and to group

themselves gives one the impression that the process is a modified

or incomplete sequence of what we see in mitotic divisions of the

chromosomes, from which they may be derived.

In the lower animals such as Rhizopods and others, the nucleus

buds out into the cytoplasm similar bodies, which undergo analo-

gous binary divisions and finally form a large progeny of staining

bodies. Later these group and form new nuclei which surround

themselves with a plasmic body, about which a new cell wall is

formed. In the Tussock egg these processes seem to stop short

of this final result, and produce objects whose fate is to be used

as food. E. W. Roserts.

SENESCENCE AND REJ UVENESCENCE

The fact that an organism at its individual beginning is “young”

and gradually loses some of the powers of youth with the passage

of time, is so commonplace that its real significance escapes us.

The further fact that one of these older organisms can, in spite of

its age, produce offspring which apparently do not have the age

of the parent, but are as young as the parent originally was at the

beginning, brings us acutely upon the problems at the basis of this

book. In what does growing old consist? How does age differ

from youth? When reproduction takes place, is youth absolutely

restored? If so, do the old materials become young again, or is

there some material within the aging body which does not itself

grow old?

158 NOTES, REVIEWS, ETC.

Many investigators believe that youth is the eternal possession

of the germ-plasm, and from this the cells of the body form,—

these latter alone becoming aged. There is in this view only one

process,—senescence. Rejuvenescence is apparent only.

Professor Child, thru the study of the lower forms par-

ticularly, in which differentiation is not so pronounced and non-

sexual reproduction and regeneration are more frequent, comes to

the conclusion that rejuvenescence is not confined to the debatable

case of the germ cells, but is found as characteristic a feature of

life as is senescence. He finds it also in agamic reproduction,

regeneration of lost parts, in the restoration of starved tissues to

activity; and the like. The author believes that senescence is not

continuous therefore; that it is interrupted now and again by

processes essentially restorative of youth; that there is no eternally

youthful stuff, but that rejuvenescence and dedifferentiation are

just as really a part of the life-cycle as is growing old.

As a criterion of youth one may take as his standard the

normal changes which are observed in the embryo formed by the

union of gametes,—e. g. rapid growth, cell division, differentiation

and other vital processes. Senescence would imply on the other

hand a decrease in these dynamic processes. Professor Child under-

takes to erect a more exact standard based upon the principle that

youth and age may be measured by the rate of metabolism in the

organism. As a test of the rate of metabolism, and hence of the

youthful or senile tendencies of tissues, the author holds that their

susceptibility to certain chemical substances is satisfactory. In

solutions strong enough to kill in a short time, the more actively

metabolic (younger) objects are killed first; whereas in weaker

solution to which acclimation is possible, those more metabolic live

longer.

The captions of the five principal divisions or parts will sufh-

ciently indicate the order and scope of the work, which is in large

part based upon the author’s original researches here given to the

world for the first time:—I. The Problem of Organic Constitution ;

IJ. An Experimental Study of Physiological Senescence and Re-

juvenescence in the Lower Animals; III. Individuation and Re-

production in Relation to the Age Cycle; IV. Gametic Reproduc-

AMERICAN MICROSCOPICAL SOCIETY 159

tion in Relation to the Age Cycle; V. Theoretical and Critical.

There are seventeen chapters in all.

The book is a worthy illustration of a monographic treatment

of a subject instead of in numerous detached papers. The bioioglcal

workers will be grateful.

Senescence and Rejuvenescence, by Charles Manning Child. Illustrated, 480 pages.

University of Chicago Press.

A TEXT BOOK OF HISTOLOGY

Messers Jordan and Ferguson, in this book, have tried to give

to students and teachers a treatment of the relatively stable matter

of histology which will overcome, thru interest, the difficulties

which the average student has in approaching and mastering the

subject. There is no doubt that histology may be, and often is,

so presented as to be deadening and full of drudgery. Indeed in

the opinion of the reviewer this is an indictment that will stand

against very much of the work done in College and University

laboratories in America today, not alone in histology but in all

aspects of morphological work. The writers justly conceive that

such interest may be stimulated and held by relating the facts of

structure to their practical ends in terms of function; and to their

meaning in terms of the generalizations which give vitality and zest

to investigation. The student of any science is entitled to the

pleasure that comes naturally from following his discoveries on

thru into conclusions that relate his facts into a system. Whenever

it has been necessary, in order to accomplish this, the authors have

not hesitated to introduce the facts of development and of function,

and the theoretical explanation which will enable the student to

appreciate the facts. This is illustrated, for example, by the dis-

cussion of the neuron theory under nervous tissues, and the theories

of the inversion of the vertebrate retina in the discussion of the eye.

In the opinion of the reviewer they have had good success in ac-

complishing their announced purpose.

The order of discussion will be made clear by giving the chapter

headings. An introductory chapter deals with protoplasm and the

cell. Then follow chapters on Epithelial Tissues; Connective

Tissues; Muscular Tissue; Nervous Tissues; End Organs; Blood

Vessels; Blood; Lymphatic System; Mucous Membranes and

160 NOTES, REVIEWS, ETC.

Glands; Skin; Respiratory System; Digestive System; Urinary

System; Reproductive System; Ductless Glands; Nervous System;

Eye; Ear. A chapter of 40 pages on Histological Technic concludes

the book.

The illustrations are well chosen, excellently executed and

liberal. The text is well written and clear. Mechanically the book

is a beautiful one.

A Text Book of Histology, by H. E. Jordan and J. S. Ferguson. 800 4

illustrations. D. Appleton & Co., New York. J aes Rages, 39

MEDICAL AND VETERINARY ENTOMOLOGY

It has long been recognized that the richest ore is often found

where two veins intersect. Under the title Medical and Veterinary

Entomology, Professor Herms treats the territory common to

Economic Entomology and Parasitology. This treatment, in the

hand of one who has himself made noteworthy contributions to both

fields, in both a scientific and a practical way, assures a book helpful

to those immediately interested in the subjects and illuminating to

the general zoologist.

The author expresses his purpose as being to systematize the

subject and thus assist in securing for Medical Entomology a place

among the applied biological sciences, rather than to supply a com-

prehensive treatise. He indicates that he hopes to be of special

service to the physician, the veterinarian, the health officer and

sanitarian, as well as to the teacher and student.

Biologically the field includes the morphology and ecology of

insects (and of the ticks and mites which are embraced in the

treatment) ; their relations to the host when they are the direct

causes of the diseases; the biology of the bacteria and protozoa by

which the diseases are caused when the insects are merely the

carriers of the germs; the physiology and pathology of the animals

attacked. While in itself a specialization, it thus rapidly broadens

out into the general interests of biologists, theoretical and practical,

when its connotations are realized.

The content and mode of treatment are apparent from an ex-

amination of the chapter headings:—Introduction; Parasites and

parasitism; Insect anatomy and classification; Insect mouth parts;

AMERICAN MICROSCOPICAL SOCIETY 161

How insects carry and cause disease; Cockroaches, beetles, thrips ;

Lice; Bedbugs; Mosquitoes as disease bearers, and their control;

Buffalo gnats and horseflies ; Common house fly ; House fly control ;

Bloodsucking Muscids; Myiasis; Fleas; Ticks; Mites. An in-

teresting final chapter is given to the discussion of venomous insects

and arachnids,—as bees, wasps, spiders, scorpions, etc. The nature

of the venom, the manner of its introduction, and its effects are

treated.

The book is well illustrated with half-tones, has numerous keys

for the identification of the principal genera, and gives the best

accepted treatments for control of the insects and of the resultant

diseases.

Medical and Veterinary Rae by William B. Herms. 394 pages, illustrated.

The Macmillan Co., New York, 1915. rice, $4.00.

CLASSIFICATION OF LEPIDOPTEROUS LARVE

Number one of Volume two of the Illinois Biological Mono-

graphs bears the above title, and is the thesis of the author, S. B.

Fracker, offered in the Graduate School of the University of Illinois

toward the degree of Doctor of Philosophy in Entomology.

The paper is divided into two parts; the first being devoted to

the question of the homology of the sete of the larvee of Lepidoptera,

and the second to the systematic outline of the families and genera.

The position taken by the author, that a final classification of

the insects based upon both the larval and adult characters neces-

sarily eliminates errors that belong to a classification based solely

on either, must commend itself to the general student. It is surely

true also that anything which will make identification of insects

more possible in the larval stages will save much trouble and time

required to rear them to maturity for more certain identification.

The proffered classification is based largely upon the sete and

the armature developed in connection with them, the head parts, the

size and shape of the spiracles, the prolegs and the hooks they bear,

and other structures somewhat less certain.

The portion of the paper that will prove most suggestive to

the general biologist is the discussion of the sete, the method of

homologizing them, and the evidence for their sufficient identity

for comparative purposes.

162 NOTES, REVIEWS, ETC.

The first step is to get a standard or type segment so far as

setal arrangement is concerned. This is done by taking the various

thoracic and abdominal segments in the more generalized members

of the two sub-orders, and plotting from these the setal arrangement

by superimposing them so as to get a composite. This composite

gave about 15 sete with approximately the distribution found on

the pro-thorax of the most generalized and primitive types. With

this composite all the different segments of every larva were com-

pared. In a similar way a type of abdominal segment is worked

out and used as a standard.

The author concludes that the first-stage larva, before entering

upon the various moults, best represents the ancestral type of

Lepidoptera and that the setal arrangement of the first instar is

essentially the same as in the ancestors, and thus serves as a con-

necting link between the more generalized type and the modern,

specialized older stages.

The various tests of homology of setz used by the author are :-—

(1) similar grouping of sete in mature caterpillars generally;

(2) similar position of sete on certain segments of modern mature

caterpillars; (3) similar arrangement of sete on all the segments

of generalized groups of caterpillars; (4) similar arrangements on

all the segments of newly hatched larve; and (5) evidences of

migration from these similar positions.

The author believes that the setal arrangement of every seg-

ment of the body of the larve of Lepidoptera has been derived

from the same ancestral type; that 12 such primary sete can be

homologized ; that these primary sete are present in the first instar;

that they may be modified by loss chiefly (abdominal segments) or

by loss and change of position. Sub-primary sete appear in later

instars and may become associated with the primary sete in ways

more or less confusing. They may develop in tuffs of various kinds.

The systematic part is based upon maturer larve, but the

characters apply for the most part to the earlier also. Elaborate

keys of the order and of the families, leading to the genera, are

supplied.

Classification of Lepidopterous Larvae, Stanley Black Fracker. Illinois Biological

Monograph Vol. II, No. I; July 1915. University of Illinois. 170 pages, 10 plates.

rice . °

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AvgertT McCatra, Ph.D., of Chicago, IIl.

at Chicago, Ill., 1883

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

at Detroit, Mich., 1890

Srmon Henry Gace, B.S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895 and 1906

A. Cuirrorp Mercer, M.D., F.R.M.S., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896

A. M. Brerre, M.D., of Columbus, Ohio,

at New York City, 1900

C. H. E1icenMAnn, Ph.D., of Bloomington, Ind.,

at Denver, Colo., 1901

E. A. Birce, LL.D., of: Madison, Wis.

at Winona Lake, Ind., 1903

Henry B. Warp, A.M., Ph.D., of Urbana, IIl.,

at Sandusky, Ohio, 1905

HeErsert Osporn, M.S., of Columbus, Ohio,

at Minneapolis, Minn., 1910

A. E. Hertzyer, M.D., of Kansas City, Mo.,

at Washington, D. C., 1911

F, D. Heap, Ph.D., of Philadelphia, Pa.,

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TABLE OF CONTENTS

FOR VOLUME XXXV, Number 3, July, 1916

The Innervation of the Ampulle of Lorenzini in Acanthias Vulgaris,

with’, Plates OC TTX) by MEIGmeY \Mictcalt ani lenu) let seein 167

A new Monostome Trematode Parasitic in the Muskrat, with a Key to

the Parasites of the American Muskrat, with Plate XXV, by F. D.

BABI R ib. arate « biniaeyalad ouass ceiaca tate eines El Ache ie Doe te ea eae 175

Notes and Reviews: Some Methods of Preparing Insects for Demon-

stration Purposes, 3 Figures, by R. W. Hegner; The Sedgwick-

Rafter Ocular Micrometer and Its Uses, 1 Figure, by C. E. Turner;

Formation of Sporangia in Stemonitis; A Drouth-Enduring Zyg-

nema; Bacteria Aid in Formation of Eurotium; Bacterial Infection

in Fresh Eggs; Some Remarkable Feeding Actions of Amebe;

Case of Brooding in Holothuriares; Effects of Activity on Nerve

Cells; Trypanosome Infection in Mammals; Improving Technic for

Showing Details in Dividing Cells; Visual Efficiency in the Use of

Optical Instruments; North American Diatomacez.............-ee. 185

IEE ROMY WAY ate tat ho4 £10 sh ww wees uw) a b.8/ a hsoe, vO IS Gite o's ave Beeb inc oe oa 195

NOTICE TO MEMBERS:

Business Sessions of the American Microscopical Society will be held

at New York City in connection with the American Association for the

Advancement of Science. See Program of A. A. A. S. for time and place.

T. W. Gattoway, Secretary.

Beloit, Wisconsin.

TRANSACTIONS

OF

American Microscopical Society

(Published in Quarterly Installments)

Vol. XXXV APRIL, 1916 No 2

THE INNERVATION OF THE AMPULL& OF LORENZINI

IN ACANTHIAS VULGARIS

By Hersert EpMoND METCALF

Teaching Fellow in Animal Biology, University of Minnesota

INTRODUCTION

In a former paper (1914) the author gave a general descrip-

tion of the ampulle of Lorenzini in Acanthias vulgaris, present-

ing evidence as to the sensory nature of these organs. Since that

time further work has been done on their innervation and is em-

bodied in this paper.

Peabody (1897) published a short article on the innervation

of these structures as shown by methylin blue preparations, and

the present author’s findings as published in the 1914 paper closely

agreed with his in the main, altho there was some doubt ex-

pressed at that time as to the nodules described being the actual

termination of the nerve fiber. Later findings indicate that a

complete impregnation was probably not present either in Peabody’s

preparations, or in the author’s in 1914. Later methods have dem-

onstrated the final terminations of the nerves supplying the am-

pull.

MeETHOpDs

New material impregnated by the methylin blue method was

sectioned, and several preparations were made by the Bielschowsky

double silver and gold process. The results therefore, were checked

,

168 HERBERT EDMUND METCALF

up between those two methods, as well as by maceration and isola-

tion of cells.

It was considered probable that if the nerves which supply the

ampulle terminate on particular cells in the ampullary pockets, iso-

lation by means of maceration and teasing would be likely to show

isolated sensory cells with their nerve terminations attached.

Material was macerated in 3% caustic potash for 24 hours, teased

immediately in glycerine and mounted in glycerine jelly; or car-

ried through the alcohols, teased in balsam and mounted. In this

way thousands of isolated sensory cells were obtained as well as

isolated supporting cells. This proved to be a very valuable method

of studying the general structure of the epithelium as well as for the

sensory cells with their nerve terminations.

THE Gross INNERVATION OF AN AMPULLA

There are eight definite groups of ampulle in Acanthias; two

on the dorsal surface, four on the ventral, and two on the lateral

surfaces of the snout and head. As might be expected these groups

are bilaterally symmetrical. The number in each group, however,

varies somewhat and each ampulla has not a fixed position on each

side. The position of four of these groups may be seen in Figure

2 (dorsal Fig. 2-A, ventral Fig. 2-C.) The two ventral groups have

not yet been divided into four by the cartilege bars of the rostrum.

There are two kinds of ampullz in Acanthias. Those with a

single duct extending from the alveolar portion to the surface, and

those with a split duct. As was explained in the previous paper

these two types are essentially alike, only in the ampullze which

have a double duct there are no primary ducts, the division be-

tween the two secondary tubules being carried completely to the

surface.

The model in Figure 1 (Pl. XXII) was made from sections

5 microns thick by the wax plate method and shows approximately

the size and shape of the ampullz having a double duct. In this

case an ampulla having a short duct leading to the surface was

selected, in order that the entire course might be modelled. This

particular ampulla had alveoli and does not follow an equal division

INNERVATION OF THE AMPULL OF LORENZINI 169

into secondary and tertiary ducts. There are several alveoli which

come off the main or secondary ducts. (Fig. 1-D.)

The external opening is nearly round and divided by the parti-

tion between the two secondary ducts. Immediately below the skin

the duct widens out to about twice the size of the opening, and

proceeds downwards to the alveolar portion. Here there is a sharp

constriction to about seven eighths its size and then the alveoli are

budded off at different levels. This fact is important for it can

be readily seen that the number of alveoli cannot be counted

from a single section, as they will not all be included. The

average number of alveoli in the ampulle of Acanthias is twenty-

two. The model shows the general appearance and proportion

faithfully with the exception that there is some slight shrinkage

so that the alveoli in the fresh total mount are somewhat more

rounded and not so long in proportion to their width. This is

probably due to the coagulation of the mucus in the lumen of the

ampulla due to the fixing fluid.

The ampulle in the two groups on the dorsal surface of the

snout are innervated by the ophthalmicus superficialis ; those of the

ventral groups by the buccalis; and those of the spiracular region

by the mandibularis externus branches of the seventh or facial nerve.

These branches also innervate the lateral line system in those

regions. The ophthalmicus superficialis may be seen under the

dorsal group in Figure 2-B, and the buccalis directly over the

ventral group in Figure 2-D.

From the main nerve trunk as it passes along close to the

alveolar portions of the ampullz, there is given off a single twig to

each ampulla containing from 5 to 15 medullated fibers. The

number of medullated fibers does not correspond at all to the

number of alveoli, altho in cases where there are a large number

of alveoli there is a large number of fibers. Roughly speaking

there are about twice as many alveoli as there are fibers supplying

the ampulla. These twigs run to the ampulla, and as the alveoli

are arranged in a circle, there is a central space into which the

nerve twig runs. (Figs. 5 and 6.) This twig does not give off

branches until it reaches a level just below where the duct begins

and where the ampullary pockets are budded off. At this point

the nerves bend laterally (Fig. 5-b) with respect to the ampulla,

,

170 HERBERT EDMUND METCALF

and radiate out between the alveoli close to where the alveoli join

the duct. (Fig. 6.)

This radiation takes place practically at the same plane for all

of the nerve fibers, and all turn at right angles to their first course

in 15 to 20 microns.

While doing this, the nerve fibers, which have up to this time

been medullated, lose their sheaths, and when they appear on the

external surface of the ampulla, between the alveoli, they are en-

tirely devoid of covering. (Fig. 3.) Thus it may be seen that

the course of the neurofibrils over the ampullary pockets themselves

is in the majority of cases, from the bases of the alveoli toward their

distal ends, speaking in respect to the orientation as shown in the

models. (Pigs 12)

As the neurofibril reaches the external surface of the ampulla,

it divides into a great number of neurofibrille which anastomose

over the entire surface of the pockets making a network over that

portion of the ampulla which is sensory in character. (Fig. 4.)

Whenever two fibrille branch a spot or nodule is formed. Nodules

are also often seen along the course of the fibrils, as well as where

a fibril apparently ends. (These nodules are labelled b in Figures

9 to 14.) These were taken by Peabody (97) and by the author

(1914) to be the endings of the neurofibrils upon the bases of the

sensory cells. This, however, I have now seen is not the case.

NERVE TERMINATIONS

The sensory cells in the epithelium are well seen both in sections

and in isolated specimens, and are the large pear-shaped cells with

broad bases and a short projection which extends out to the lumen

of the ampulla. Each of these cells is surrounded by four or five

supporting cells which fit over the top as shown in Figure 9. In

macerated preparation the pear-shaped cell comes away from the

supporting cells and leaves the small hole where its projection

reached the lumen. (Figs. 7-a and 8-a.) The supporting cells

in macerated preparations give a table-like appearance as shown

in Figure 8, and they occasionally stick together as in Figure 7.

Figure 9 is a drawing of a sensory cell complete with its four sup-

porting cells and its nerve termination. All of these cells are more

INNERVATION OF THE AMPULLZ OF LORENZINI 171

or less rounded due to the fact that they swell somewhat in the

maceration process. This gives a more or less rounded appear-

ance to their bases which appear flat in sections. Figure 10 is a

drawing of an isolated cell which was cleared and drawn in optical

section so as to show the small projection from its upper surface

to the lumen.

The neurofibril, which has been traced to the small nodule on

the base of the cell, does not stop there but has a small process ex-

tending up between the sensory cell and the interstitial cell.

(Labelled c Figs. 9-14.) This process does not readily impreg-

nate with methylin blue but can be seen occasionally by very

careful focussing with the oil immersion lens in cases where it does

occur. It has been seen a sufficient number of times to justify the

statement that in all probability all of the pear-shaped cells have

such a termination. This process which was entirely overlooked

in the previous paper, is the final termination of the nerve. This

process arises from the nodule on the base of the cell and is very

slender. It extends to the level of the lower border of the nucleus

and there flares out with a fork and encloses an area which in my

preparations appeared lighter than the rest of the nerve. It must

be understood that this oval area is NOT on the inside of the cell,

but closely applied to its external surface. This form of ending is

much like the terminations of the sensory fibers in the ear of

Mustelus as described by Morrill (97), and may be taken as evi-

dence of the homology of these ampullz with those of the ear.

In isolated sensory cells impregnated by the methylin blue

method the cell may sometimes be seen with this process connected

with the basal nodule as well as with part of the torn neurofibril.

(Figs. 11 and 14.) Morrill (97) in his figures shows many cells

which have no hairs, and yet were sensory in character. These

cells in the ampullary pockets look somewhat like hair cells with the

exception that the process is rather thick and does not project out

into the lumen. In every case, however, it connected with the

lumen. This is not as readily seen in sections as it is in isolated

specimens, because in sections these sensory cells are so large that

it is only occasionally that a section cuts the process exactly to show

it extending to the lumen. In thick sections, by focussing, it may

,

172 HERBERT EDMUND METCALF

be recognized. It may thus be seen that the real termination of

the nerve supplying the ampulle of Lorenzini in Acanthias is a

slender process extending from the basal nodule to a point about

half way up on the cell, and there flaring out into an oval plate

in close contact with the sensory cell.

SUMMARY

1. Each ampulla is innervated by 5 to 15 medullated fibers

from the seventh or facial nerve.

2. These fibers run into the central space of the ampulla, turn

sharply and radiate laterally to reach the external surface of the

ampulla.

3. From there they radiate downwards forming a network

with nodules on the bases of the sensory cells.

4. The termination in Acanthias vulgaris is a light oval plate

closely applied to the sensory cell at about its middle and connected

with the basal nodule by a slender strand.

I wish to thank Dr. J. B. Johnston for his kind help during

the course of this investigation.

BIBLIOGRAPHY

1678. Lorenzini, Stephan—Osservazioni intorno alle Torpedini. Florence.

1897. Morrill, A. D—The Innervation of the Auditory Epithelium of Muste-

lus canis (de Kay). Journ. Morph. Vol. XIV, No. 1.

1897. Peabody, J. E—The Ampulle of Lorenzini of the Selachii. Zool.

Bull. Vol. 1, No. 4.

1898. Forsell, Gustavy—Beitrage zur Kenntniss der Lorenzinischen Ampul-

len bei Acanthias vulgaris. Zeitsch. f. Wissensch. Zool. Vol. 65.

1910. Parker, G. H—The Influence of the Eyes, Ears, and Other Allied

Sense Organs on the Movements of the Dogfish Mustelus canis

(Mitchel). Bull. of the U. S. Bureau of Fisheries, Vol. 29.

1914. Metcalf, H. E—The Ampulle of Lorenzini in Acanthias vulgaris.

Trans. Am. Microscop. Soc. Vol. XXXIV, No. 2.

PLATE XXII

E XXIII

INNERVATION OF THE AMPULLZ: OF LORENZINI 173

DESCRIPTION OF PLATES

PiLate XXII

Fig. 1. Drawing of a wax model of an ampulla having a double duct.

A—nerve bundle entering central space. B—ramification of un-

medullated fiber over alveolus. C—anastimosis of neurofibrils

over distal end of alveolus. D—alveolus coming directly off

secondary duct. E—skin of fish. F—partition between the two

secondary ducts and openings.

Pirate XXIII

Fig. 2. A transverse section of an Acanthias pup just forward of the nasal

capsules. A—Dorsal group of ampulle. B—Ophthalmicus super-

superficialis. C—Ventral group of ampulle. D—Buccalis nerve.

E—Lateral line system. F—Lateral line system. x15

Fig. 3. Drawing showing the loss of the medullary sheath as the nerve

bends laterally. Bielschowski method. a—point where loss of

sheath occurs. X 180

Fig. 4. Showing the anastimosis of the neurofibrils over the ampuliary

pocket. Methylin blue impregnation. a—point where nerve leaves

sheath. X 250

Fig. 5. Diagram to show nerve entrance and lateral radiation. Longi-

tudinal section, Bielschowski method. a—nerve twig. b—nerve

radiating laterally. c—ampullary pocket. d—duct. X 180

Fig. 6. Transverse section showing nerves radiating laterally. Bielschowski

method. a—nerve radiating laterally. b—ampullary pocket.

X 180.

174

Fig.

Fig.

Fig,

Fig.

Fig.

and

10.

a1,

12.

13,

14,

HERBERT EDMUND METCALF

Pirate XXIV

Group of supporting cells from which three sensory cells have been

removed by maceration. a—opening by which the sensory cell

connected with the lumen.

Group of supporting cells from which one sensory cell has been

removed by maceration. a—opening by which the sensory cell

connected with the lumen.

A group of supporting cells enclosing a sensory cell with its nerve

termination. a—projection of the sensory cell to the lumen, b—

basal nodule. c—nerve termination,

Optical section of an isolated sensory cell with three supporting

cells, and nerve termination. a—process extending to lumen.

b—basal nodule. c—nerve termination.

A sensory cell isolated by maceration to show process and nerve

termination. a—process extending to lumen. b—basal nodules.

C—nerve termination.

Section directly through the process extending to the lumen show-

ing nerve termination on side of cell, and two supporting cells,

Methylin blue impregnation. a—process. b—basal nodule. c—

nerve termination.

Section directly through the process extending to the lumen show-

ing nerve termination on middle of cell, and two supporting cells.

Lettering as in Figure 12.

A sensory cell isolated by maceration to show Process and nerve

termination. Lettering as in Fig. 11.

All figures in Plate XXIV were drawn with the oil immersion lens

have a magnification in the plate of 2000 diameters.

PLATE XXIV

A NEW MONOSTOME TREMATODE PARASITIC IN THE

MUSKRAT WITH A KEY TO THE PARASITES

OF THE AMERICAN MUSKRAT*

By FRANKLIN D. BARKER

Professor of Parasitology, the University of Nebraska

CONTENTS

PAECACA TICE LOL ~ c's ao we orcioraranc fh RNS Oe Sere SAT REST eae Ler ea Reet eae fod al ete teu ede ce 175

Morphology of Nudacotyle novicia, Gen. et Sp. MOV........e eee cece eens 175

BE ECIAIIC CISCUSSION 2. 213 wosiadiex oticis Hoesen ene sa eee elas 179

Key to the Parasites of the American Muskrat..............c00cecccens 182

Mme TEN eer Oe re Ik) tee eM er Gs ions Bhi bth otra akin an hate Maat ater 183

RPI IEE ath ays .cic Sana atayata MA tea a aie teresa ease lees mialaratses tale latedelaten tc Seat bes Bearey vars 184

aR cm Ge MAF site WSC ES RIO N, Sher Lenni tla utayapalisie teers, Siarsiareretsiereiateteeretale XXV

INTRODUCTION

In studying the parasites of muskrats shot on Lake Chisago,

Minnesota, last summer (August, 1915), in addition to several

species previously reported for muskrats Barker (:15, p. 184) more

than a hundred specimens of a small monostome trematode hereto-

fore unrecorded for the muskrat were found in one male animal.

MorPHOLOGY

To the unaided eye the trematodes appear as very small, thick

ovals or globules, milk white in color. The length varies from

0.709 to 0.899 mm., the breadth from 0.501 to 0.657 mm. Under

the hand lens or binocular the anterior third or fourth of the body

is seen to taper gradually. The posterior third of the body also

tapers slightly, but the end is markedly truncate. A rather wide

but shallow indentation is fairly constant on each side in the region

of the middle third of the body, and the body is widest just an-

terior to this constriction. A slight, wide but shallow, indentation

also occurs in the center of the posterior end of the body, which

marks the outlet of the excretory vesicle. The dorsal surface of

the body is strongly convex in both diameters; the ventral surface

is concave or cupped.

The lateral and posterior margins of the body turn ventrad and

mesad forming a ventral horse-shoe-shaped shelf one-fifth to one-

e Ho oe from the Zoological Laboratory of the University of Nebraska,

oO. ; j

176 FRANKLIN D. BARKER

fourth the width of the body. The anterior fifth of the body is often

strongly flexed ventrad, this flexed condition together with the

ventral shelf forms a characteristic elongated ventral cavity or

cup-like groove which undoubtedly functions as an effective hold-

fast in lieu of an acetabulum, which is absent in this form. The

ventral groove is wide and shallow anteriorly and narrow and deep

posteriorly. In some specimens the anterior end of the body is

straightened out obliterating the cavity at that end. The posterior

end likewise may be straightened, thereby breaking the continuity

of the shelf and altering the shape of the ventral depression. Ven-

tral papille or ridges are entirely absent and the body is devoid of

spines or spinelets.

Digestive tract: Only one sucker, oral in position is present.

It is slightly sub-terminal, quite muscular, circular or oval jn shape

and measures 0.05 to 0.06 mm. long by 0.052 to 0.065 mm. wide.

The esophagus is straight and about twice as long as the diameter

of the oral sucker. A pharynx is absent. The intestinal caeca lie

in the median third of the body, and are slightly undulating but

without pockets. Their course is nearly straight to the posterior

half of the body where they make a decided wide outward bend, but

in the posterior fifth of the body they again turn medianward and

approach each other but remain separated by a median space equal

to about four times their diameter. Both caeca end blindly in the

posterior eighth of the body.

Genitals, female: The ovary lies in the extreme posterior end

of the body, just to the left of the median line and dorsal to the left

testis. Its bulk lies between the posterior ends of the testes, but a

small portion overlaps one testis. The ovary is elongated and

somewhat convoluted or twisted and the convolutions do not all lie

in the same plane which gives a lobed or segmented appearance to

the organ in any one plane of focus. The oviduct arises from the

internal lobe of the ovary and almost immediately penetrates the

shell gland and emerging as the uterus proceeds with several coils

anteriorly and to the left around the base of the cirrus pouch. It

then passes transversely across the entire body of the worm and

in increasingly larger ascending transverse coils extends anteriorly

to the level of the bifurcation of the digestive tract, then descend-

MONOSTOME TREMATODE PARASITIC IN MUSKRAT DAE

ing in wide transverse folds or coils to the level of the cirrus pouch

again it passes posteriorly in a sharp right angle turn around the

base of the pouch and merges with the vagina. The vagina is

narrower than the uterus and lies just posterior to and parallel with

the cirrus pouch. The lumen of the terminal third of the vagina

is widened and its wall wrinkled affording considerable expansion

for the reception of the unusually large thick cirrus. The vagina

terminates externally in a large opening the vulva, or female genital

pore, slightly posterior and to the left of the opening of the cirrus

pouch. The lumen of the terminal portion of the vagina is lined

with thick cuticula and surrounded by two muscular sheets, one

of longitudinal and one of circular muscle fibers. This muscular

wall is in turn surrounded by a large oval mass of gland cells. In

many specimens the lumen of the vagina and the contiguous trans-

verse descending arm of the uterus are filled with sperm cells. The

vitellarium consists of two compact convuluted tubular masses extra-

cecal in position, one lying on each side of the body in the middle

third. From the posterior portion of each gland a transverse vitel-

line duct passes posteriorily and mesad and enters a small but definite

oval vitelline reservoir median in position and lying between the

fourth and last posterior fifths of the body just anterior to the shell

gland. Neither a Laurer’s canal nor a receptaculum seminis were

found.

The shell gland lies in the median plane of the posterior fifth

of the body between the testes. It is triangular in shape, fairly

large, and well defined, tho not prominent. The oviduct passes

thru the center of its mass, the cells of which are arranged in a

characteristically radiating manner around the lumen of the oviduct.

Eggs: The eggs are very numerous, of a light straw color,

oval in shape and about twice as long as wide. The length varies

from 0.02 to 0.024 mm., and the breadth from 0.010 to 0.013 mm.

A well defined operculum or lid is present at the narrower end of

the egg. At each pole the shell substance is drawn out into a very

long solid tapering filament. Each polar filament is often five times

as long as the egg proper. The filaments of the eggs in utero inter-

twine forming tenacious strings of eggs which can withstand con-

siderable tension. The manner in which these long polar filaments

178 FRANKLIN D. BARKER

are formed in the moulding of the egg shell offers an interesting

problem.

Genitals; male: The two large testes are lateral in position,

extraczecal, one lying on each side, in the posterior third or fourth

of the body. They are solid oval or longated bodies longer than wide

and are frequently two to five lobed. Their entire mass does not lie in

the same vertical plane of the body. The left testis is generally larger

than the right one. From each testis a short transverse vas efferens

runs medianward, the two uniting to form a wide tubular convo-

luted seminal vesicle having its base in the median plane at the level

of the anterior margin of the shell gland. From this point it passes

forward turning to the right around the base of the cirrus pouch

which it enters from the dorsal surface. The cirrus pouch is com-

paratively very large, its length being one-third to one-half the

width of the body and lies transversely across the median portion

of the body at the anterior level of its posterior half. It is pear-

shaped with its base to the right. The base contains an enlargement

of the seminal vesicle which is surrounded by the cells of the prostate

gland. The middle portion and neck contain the large thick cirrus.

The lumen of the cirrus is markedly eccentric, lying nearer the under

or ventral surface, and is lined with a thick cuticula. Internal to

this lining is a single sheet of longitudinal fibers which aid in the

retraction of the cirrus. The bulk of the cirrus is composed of

parenchyma tissue and its musculature is poorly developed. No

cirrus spinelets are present. The extruded cirrus is always

markedly flexed or curved.

Excretory system: A slight depression occurs in the middle of

the posterior end of the body and in the center of this depression

is a small excretory pore. A very short canal lined with cuticula

and surrounded by a row of radiating gland cells connects the pore

with a small stellate shaped excretory vesicle or reservoir. From

the reservoir four to eight fine radiating canals lead off in all direc-

tions and planes. The excretory tubules immediately branch and

rebranch, soon becoming so attenuated as to make it impossible to

follow their course.

MONOSTOME TREMATODE PARASITIC IN MUSKRAT 179

SYSTEMATIC DISCUSSION

Kossack (:11, p. 553) in a thoro revision of the mono-

stome trematodes, grotips the five heretofore recognized fam-

ilies in two families, the Cyclocelide and the Notocotylide. He

clearly points out that the Notocotylide differ essentially from the

other families of monostomes with respect to the following strik-

ing characters: the absence of an acetabulum; the presence of ventral

glands (driisenpakete) ; the absence of a pharynx; the position of

the extraczcal testes and the intercaecal ovary in the same plane in

the extreme posterior end of the body; the elongated vagina and cir-

rus sac, which incloses a part of the much convoluted seminal vesicle ;

the strongly developed vitelline glands lying lateral to the intestinal

czeca in the posterior half of the body; the absence of a receptaculum

seminis; the uterine coils posterior to the cirrus pouch, and the

presence of a polar filament at each end of the egg.

Lihe, ( :09, p. 33) created a new genus Paramonostomum to con-

tain Monostomum alvcatum Mehl. Paramonotomum alveatum

Lithe, conforms to the diagnostic characters of the Notocotylide

with the exception of the presence of ventral glands, which both

Lithe and Kossack report they were unable to find either in toto

preparations or in sections.

We seriously question the validity of creating a new genus for

this species on a single important differentiating character, namely

the absence of ventral glands. The number of rows of these ventral

glands varies from two in Notocotylus diserialis Ssinitzin to three

in Notocotylus triserialis Diesing and five in Notocotyle quinqueser-

tale Barker and Laughlin and their complete absence in a species

might naturally be expected. Their absence then, it seems to us is

of specific rather than generic import.

Linton (:10, p. 69) has described a new species representing a

new genus of monostomes which he found in three species of tropical

fishes. As described by Linton the characters of this new species

tally with the characters given for the Notocotylide with the fol-

lowing exceptions: ventral glands are absent; “the genital apera-

ture is on the left margin approximately at the anterior third of the

body ;” “the cirrus pouch is relatively large,” and a seminal vesicle

is present lying “anterior and dorsal to the ovary.”

,

180 FRANKLIN D. BARKER

The monostome which we have described has a number of the

diagnostic characters of the Notocotylide such as, the absence of a

pharynx; the caudal and parallel position of the extraczcal testes

and the ovary; the strongly developed and laterally placed vitelline

glands and the eggs with long polar filaments. On the other hand it

differs essentially from all of the described species of Notocotyliade

in the absence of ventral glands, with the exception of Paramonos-

tomum alveatum; the posterior position of the cirrus pouch, vagina

and genital pores; the shape and large size of the cirrus and pouch;

the position of the uterine coils anterior to the cirrus pouch, and

the compact convoluted vitelline glands. Notwithstanding these dif-

ferences it obviously more closely resembles the Notocotylide than

the Cyclocelide. The question immediately arises as to what char-

acters and what combination or complex of characters must be

present in a species to rightly place it in the family Notocotylide.

As Kossack aptly remarks “Man ist bei der Schaffung des Tremato-

den—systems induktiv vorgegangen.” It is often difficult to de-

termine what morphological characters are of real phylogenetic im-

port and therefore afford a reliable basis for a natural classifica-

tion and what characters are due possibly to environment and there-

fore may be expected to vary and can not be relied on in determin-

ing the true systematic position of a given species. It seems to us

that such a complex of characters as the absence of a pharynx; the

posterior position of the testes and ovary in the same transverse

plane with the testes extraceecal and the ovary situated between

them and the presence of polar filaments on the eggs may be con-

sidered of real phylogenetic significance and for this reason we do

not hesitate to place this new species in the family Notocotylide.

Kossack (:11, p. 554), divides this family into the two sub-families

Notocotyline and Ogmogasterine on the difference in the character

or arrangement of the ventral glands. In the Notocotyline they are

in rows (Reihen Drusenpakete), in the Ogmogasterine the glands

are arranged along long ribs (‘‘Langsrippen, auf denen Drisen-

pakete ausmtinden”). We agree with Kossack that such a division

is well founded and further propose the creation of a third sub-fam-

ily to contain such species as those described by Linton and the

present paper and others that may be found later which have the

general character complex of the Notocotylide but differ from the

MONOSTOME TREMATODE PARASITIC IN MUSKRAT 181

two recognized sub-families with respect to particular characters

such as the position of the genital pore; the character of the cirrus;

the nature and extent of the vitelline glands and the uterine coils

and the absence of ventral glands. For this new sub-family we

propose the name Nudacotyline (devoid of cups) and designate the

following characters as diagnostic.

Sub-family Nudacotyline

Small Notocotylide, with thick bodies and without ventral

glands. Ventral surface may be strongly cupped. Genital pore

lateral (to right or left of median line) decidedly posterior to the

intestinal bifurcation. Cirrus pouch large, thick, pear-shape, en-

closing a small portion of a convoluted winding seminal vesicle.

Vitelline glands strongly developed, compact convoluted masses,

extracecal and lateral in the posterior half of the body.

Uterus strongly developed, transverse folds extend laterally over

the intestinal czeca and lie anterior or posterior to the cirrus pouch.

Eggs with long polar filaments.

Type genus: Nudacotyle, mihi; other genus, Barisomum Lin-

ton. As the type species of the genus Nudocotyle we designate the

form described in the present paper which we have named

Nudocotyle novicia.

182 FRANKLIN D. BARKER

KEY TO THE PARASITES OF THE AMERICAN MUSKRAT

Bady, fat, tunsegmented: 26o0c3..6 cen das eee a Be ee eee III

Body flat; : Segmented «joj. ite cuciatoli-ave cos ehecrd CE eens ok aL II

Body cylindrical; nunsegmented 23.5 wh aca cee te aaa I

I. Body differentiated into long slender region and shorter thicker

PORION Si 5.5 Talaislerca ei sie pod a aie Se ieee eee Ae ie ae Zz

1. Body not differentiated into two regions. Body stiff, opaque;

mouth surrounded by prominent lips............cceccceeceecs b

a. Body thread-like; mouth not surrounded by prominent lips.

(1) Body hair-like (capillary): male with small bursa and single

long’ spicule> ‘eggs ‘with polar’ pligs./. 0). ) 2.5 ee

EOE) MN at a i) oR Capillaria ransomia (Barker, 915: 197)

(2) Body thread-like; male with well developed bursa and two

short spicules; eggs without plugs............sseccceeces

RA 3 ou.F Trichostrongylus fiberius (Barker, 1915: 196)

b. Body stiff, opaque; mouth surrounded by three prominent lips

PERO NS, CeAe ED. SEAR D IRB Ie CRPOEO TD RACY ae Ascaris sp.*

2. Body stiff, opaque, divided into long slender cephalic region and

shorter, thicker. body region. <5 .).%',<.. ssc om eee eon ence

SES eee etal maleic cohen Meee Trichuris opaca (Barker, 1915: 195)

Species inquirende.

Filaria sp. (in collection of Bureau of Animal Industry, Wash-

ington, D. C.)

Mey around in cysts: Wn MVeEr: y..6...6s ewe cscs ee oe TER OA Sele be be 2

Not.in ‘cysts sia testine. 62). b.s.ciesnoe sco > dash o wx eateiee aie 1

1. (1) Body thin, flabby; genital pores unilateral; single row of

hammer-shaped hooks on rostellum; three large testes

presentivis: snus Hymenolepis evaginata (Barker, 1915: 194)

(2) Body thick, stiff; genital pores alternate; double row of long

and short hooks on rostellum; testes numerous............

SPE eee ea Anomotenia telescopica (Barker 1915: 194)

2. Bladder-like ‘cysts: in liver... .:....saieee od ov cs cok 1a eee

Cysticercus fasciolaris (Stiles and Hassall, 1894; Linton, 1915: 46)

III... Two suckers, oral and acetabular, presentiny ...+o..-seeunee eee eee 2

One sucker, oral’ or caudal, present.....7.; aceds eaves eae eee ee 1

1.. Oral sucker not-present.’.,...\...0 sce se ghee eee es B

Oral sucker’ presents 5. 5:00:24... ovete sie ak Ree tte ee A

A: Ventral’ papilla absent.’s..50). ss) .¢ceeeeeeaee eke sea b

Ventral’ papille present... 39k /b cae ke hoki ee a

a. (1) Three longitudinal rows of ventral papille present......

A fagtenere (Ca uae Catatropis filamentis (Barker, 1915: 190)

(2) Five longitudinal rows of ventral papille present. .Noto-

cotyle quinqueseriale (Barker and Laughlin, 1911: 261)

Unpublished research by Bessie Noyes.

MONOSTOME TREMATODE PARASITIC IN MUSKRAT 183

ace): * Body © thin, iapere ea eis sala nccie ov otc wccsian ec acleawcine

ede ce Monostomum affine? (Leidy, 1858: 110-112)

(2) Body thick, ventral. aspect cupped... .).).66. 60s ccc ccscces

a sae b Sale ge Nudacotyle novicia (the present paper)

B. Caudal sucker present |

(1) Testes branched.Cladorchis (Stichorchis) subtriquetrus=

Amphistomum subtriquetrum® (Leidy, 1888:126-127)

(2). ‘Testes: slightty loted’s : sty. aa aaa satds algae clash he oia's 6, aes) < 2

2 thie cea cena nean te Reat Wardius zibethicus (Barker, 1915: 192)

2. Body divided into cephalic and caudal regions................ B

Body not: divided. ss daew iis casa cre av wiaus gacome H gaae taaaean A

A. Oral sucker surrounded by collar, bearing spines............. b

Acs Oral sapien without CGllat. f. fxs ois oe 2 ae oie nclaeaeal cla ele Saree

Bfpcars wt sunt atevaieroler seiaioters Plagiorchis proximus (Barker, 1915: 192)

Bes ey TIRE TESA a eta ta, atdalse alatnc wou uo ninee G pacts bb

dam orsurews (OUstOL LOU) erate ki ctatevares a. aneletaseie ciara alavannveraleinia ay oel tee

ABR E. Echinoparyphium contiguum (Barker, 1915: 187)

bb. Body 3 to 8 times longer than wide..................: bbb

aga. - Body’ 10to 15 times: longer than wide. o/s... 6.6 e hoe

SPE RY A See 1c Echinostomum coalitum (Barker, 1915: 185)

bbb. Uterine coils definitely transverse................2.. bbbb

Aad AOE CLINE LCOS ICOM AC ta erase che eid chee tater olaret ad ualel acalaieis

Beery Echinostomum callawayensis (Barker, 1915: 188)

bbbb. (1) Anterior testis immediately behind the shell gland...

BBS be Echinostomum armigerum (Barker, 1915: 189)

(2) Anterior testis separated from shell gland..........

..Echinostomum echinatum (Leidy, 1888: 126-127)

B. Body divided into cephalic and caudal regions..................

1S EASE eee ee Hemistomum craterum (Barker, 1915: 191)

*We question the correctness of the identification of this =» oor and surmise that

it is a species of Notocotyle.

8The identification of this species is questionable and we surmise that it is Wardius

zibethicus. We wish to express our thanks to Doctor Joseph Leidy, Jr., for his efforts

to secure for us the original material of Professor Leidy and regret that it has been

misplaced or destroyed and is not available for comparative study.

SUMMARY

1. A new species of monostome trematode, Nudacotyle novicia,

from the intestine of the American muskrat is described with

four figures.

2. The suggestion is made that Paramonostomum alveatum Lithe

rightly belongs in the genus Notocotyle.

3. A new sub-family, Nudacotyline is created under the Noto-

cotylide with Nudacotyle novicia as the type genus and

species.

4. A key to the parasites of the Meiesian muskrat i is given.

184 FRANKLIN D. BARKER

Papers CITED

Barker, F. D.

1915.. Parasites of the American Muskrat (Fiber zibethicus) Journal

of Parasitology, v. 1, pp. 184-197.

Kossack, W.

1911. Uber Monostomiden. Zool. Jahrb., Syst. v. 31, pp. 491-590.

Lerpy, JOSEPH

1858. Contributions to Helminthology. Proc. Acad. Nat. Sc. Phila. v.

10, pp. 110-112.

1888. On the Trematodes of the Muskrat. Proc. Acad. Nat. Sc. Phila.

v. 40, pp. 126-127.

Linton, Epwin

1910. Helminth Fauna of the Dry Tortugas II. Trematodes. Publica-

tion of the Carnegie Institution of Washington. No. 133, pp.

11-98.

1915. Cestode Cysts from Muskrat. Journal of Parasitology, v. 2, p. 46.

LUuHE, Max

1909. Parasitische Plattwurmer, in: Brauer, Die Stisswasser fauna

Deutschlands, v. 17: Trematodes, Jena.

SsINITzIN, D.

1897. Endoparasiten der Vogel aus der Umgebung Warschaus. Arb.

Labor. zool. Kabin. Univ. Warschau v. T. 1896, 1897.

Stites, C. W. and Hassatt, A.

1894. A Preliminary Catalogue of the Parasites Contained in the Col-

lections of the United States Bureau of Animal Industry, United

States Army Medical Museum, Biological Department of the

University of Pennsylvania (Coll. Leidy) and in Coll. Stiles

and Coll. Hassall. Vet. Mag., Phila. v. 1, pp. 245-354.

EXPLANATION OF PLATE XXV

Fig. 1.—Nudacotyle novicia Barker, free hand drawing of unstained

and uncompressed specimen, ventral aspect, under binocular. OS, oral sucker;

C, cirrus, extruded; GP 4, genital pore, male; GP, genital pore, female;

S, ventral shelf; VC, ventral cup.

Figs. 2 and 3—Eggs of Nudacotyle novicia. P, polar filament; Op,

operculum.

Fig. 4.—Nudacotyle novicia Barker, camera lucida drawing of stained

and slightly compressed specimen, dorsal aspect. CP, cirrus pouch; ES,

esophagus; Ex, excretory reservoir; GP 4, genital pore, male; GP 9, genital

pore, female; I, intestine; Ov, ovary; OS, oral sucker; SG, shell gland;

SV, seminal vesicle; T, testis; Ut, uterus; VG, vitelline gland; VD, vitelline

ducts; VR, vitelline reservoir.

Wi

PLATE XXV

Sy

Y

~~

DEPARTMENT OF NOTES, REVIEWS, ETC.

It is the purpose, in this department, to present from time to time brief original

notes, both of methods of work and of results, by members of the Society. All

members are invited to submit such items. In the absence of these there will be given a

few brief abstracts of recent work of more general interest to students and teachers.

There will be no attempt to make these abstracts exhaustive. They will illustrate progres,

without attempting to define it, and will thus give to the teacher current illustrations, and

to the isolated suggestions of suitable fields of investigation.—[Editor.]

SOME METHODS OF PREPARING INSECTS FOR

DEMONSTRATION PURPOSES

In teaching entomology it is of considerable importance to pro-

vide the students with as much material as possible to aid them in

identifying their specimens, to give them an adequate idea of the

great number of insects available for study, and to impress upon

them the value of insects for the demonstration of biological prin-

ciples. It is therefore the custom to display upon the walls of the

laboratory or on tables collections of insects which will serve these

purposes. In the following paragraphs I wish to describe, with the

aid of photographs, three methods that have been used in the en-

tomological laboratory at the University of Michigan, which may be

of interest to other teachers of the subject.

1. A method of displaying insects for purposes of identifica-

tion. Photograph 1 shows a laboratory table, two feet wide and

five feet long. On it is a removable frame which will carry six

Comstock boxes inclined in such a way that their contents can be

studied with ease. These boxes can be removed and others put in

their place without difficulty. It is thus possible to display a large

number of insects in a small space with the use of a laboratory table

from which the frame that holds the insect cases can be removed and

which therefore becomes available for other purposes. The frame-

work above the boxes may be used for posting laboratory directions.

notices, drawings, etc.

2. A method of displaying the life histories of insects. As is

well known, an excellent method of displaying stages in the life his-

tories of insects is to place the various stages in Riker mounts.

These may be given to the students for study but may also be

grouped in such a way as to make beautiful and instructive wall ex-

186 NOTES, REVIEWS, ETC.

hibitions. Photograph 2 shows a number of such groups, each

group consisting of three or four mounts and arranged according to

the economic importance of the insects represented, e. g., one group

contains insects of the household (clothes moth, cheese skipper and

carpet beetle) and another includes three shade tree pests (the

horned tail, tussock moth, and leopard moth.) Students and visitors

show considerable interest in these exhibits and, perhaps uncon-

sciously, derive a great deal of information from them.

3. A method of displaying insect galls. Biologically the gall

insects are among the most interesting of the whole class. The

insect galls may be prepared for exhibition in the following manner

(see Photo 3.) Racks three feet long, eight inches high, and two

and one half inches deep are made, with the top piece hinged at

both ends. Strips on the edges at the top and bottom prevent the

bottles from falling out. Galls on stems are dried and placed in

large mouthed vials about two inches in diameter, and a label is

placed at the bottom. Galls on leaves are preserved in 10% for-

malin and placed in bottles about two and one half inches in diame-

ter. The bottles or vials fit loosely enough in the racks so that they

can be turned around and all sides of the galls can thus be examined

but their removal is prevented by the strip near the top and bottom.

If, however, it becomes necessary to take out a bottle, the hinge at

one end of the top can be disjointed and the desired specimen re-

moved. A background of white cardboard helps to bring out the

characteristics of the galls. Such a rack as that described may, of

course, be used for other material both zoological and botanical.

Zoological Laboratory, R. W. HEGNER.

University of Michigan.

THE SEDGWICK-RAFTER OCULAR MICROMETER

AND ITS USES

In 1889 Prof. W. T. Sedgwick and Mr. George W. Rafter de-

veloped the so-called Sedgwick-Rafter method for enumerating

microscopic organisms to be found in water,—a procedure which has

since come into general use among biologists, chemists and engineers

investigating or in charge of water supplies, and has been incorpor-

ated as a part of the Standard Methods of Water Analysis adopted

|

Fic.

XXVI1

PLATE

?

Fic.

PeAgtEee aN Vole

PrATE, XO Ville Eres

PLATE XX VII BIG; 2

AMERICAN MICROSCOPICAL SOCIETY 187

by the American Public Health Association. This process, the de-

tails of which need not be mentioned here, involves the concentra-

tion of organisms by means of a sand filter and the microscopic

examination of cubic millimeter volumes of the concentrate. The

ocular micrometer which was devised for the purpose of ruling off a

square millimeter surface on the “ringed” slide has been found useful

not only in the enumeration and identification of organisms, but also

in the broad field of general microscopic work and perhaps deserves

a word of commendation to microscopists.

The micrometer is sub-divided as shown in the accompanying

diagram and when used with an ocular of the No. 4-x Spencer type

(2 inch) and a 16 mm. objective, can be so standardized by the aid

of a stage micrometer that the large square will outline a square

millimeter surface. The smallest square will then be 20 micra on

a side and the micrometer will form a convenient measure for the

larger microscopic objects. By only a slight change in the tube

length, moreover, a standardization with the 4 mm. objective can

be made which will increase the magnification five-fold, thereby

reducing the side of the large square to 200 micra and that of the

smallest square to four, so that, with the high power, the dimensions

of all but the very smallest microscopical organisms can be readily

obtained.

But ready adaptability to either high or low powers of the

microscope is not the only commendable feature of this type of

micrometer. There is a marked advantage in the way it is ruled

into squares of various sizes. It enables one to measure the length

and the breadth of an object at the same time and yet leaves the

greater part of the field of vision relatively free from lines inter-

fering with clear definition of objects. It is thus adapted to the

use of the beginner as well as to that of the seasoned microscopist.

The student beginning microscopic work in zodlogy, botany or his-

tology, for example, is studying anatomy with no basis or standard

of size-comparison, other than that offered by different objects in

the same field. The standardization and use of the micrometer

gives him an appreciation of the magnifying power of the microscope

by demonstrating the apparent size of a familiar and fundamental

unit, the square millimeter, and teaches him the approximate relative

188 NOTES, REVIEWS, ETC.

size of the microscopical linear unit or micron. The student finds

the device convenient to handle, and easy to use and soon acquires a

mental scale of unit areas by which he can estimate the size of or-

ganisms or other structures in micra much as he judges of macro-

scopic structures in centimeters or inches.

Ocular micrometers may be prepared either by engraving or

photography and are not difficult to procure. Engraved microme-

ters are somewhat superior and are sold by Bausch and Lomb under

the name of “Whipple’s Eye-Piece Micrometer” at $3.50 each.

Those made by photography are much less expensive and have been

found entirely satisfactory. In either case, the actual size of the

large square ruled on the glass should be 7 mm. on a side. In

photography the lines are produced on lantern-slide glass by photo-

graphing a specially prepared sketch. The glass is then cut and

mounted on a clean cover slip with gum damar. The only difficulty

in using this type arises from the fact that the lantern-slide glass is

rather thick and cannot be perfectly cleared without removing the

fine lines. The fault is not serious, however, and may be readily

overlooked if expense must be considered, for these micrometers

can be made for about'75c each.* This is relatively very inexpen-

sive, for the common linear ocular micrometer, which is much less

adapted to work with living forms and hardly more valuable for

exact measurements, is not obtainable for less than $1.25.

The advantages of this type of micrometer are its ready adapta-

bility to general use with either high or low powers of the micro-

scope; the definition of measured squares or unit surfaces, which

are easier to use and to fix in mind than are linear units; a com-

paratively unobstructed “field’’; and (in the photographic product)

low cost.

*Unmounted ocular micrometers may be secured at this price from Mr. B. S.

Turpin, 30 Trinity Place, Boston, Mass.

C. E. Turner,

Instructor and Research Associate Department

of Biology and Public Health. M. I. T.

AMERICAN MICROSCOPICAL SOCIETY 189

FORMATION OF SPORANGIA IN STEMONITIS

Hilton (Jour. QO. M. C., Apr. 1916) contributes an interesting

note on the method of forming sporangia in this common myceto-

zoan. He had the good fortune to find considerable masses of

plasmodium just in condition to observe the whole process. At

noon the plasmodium formed somewhat rounded, solid, cushion-

shaped masses. This surface differentiated in about a quarter of

an hour into frothy, bubble-like hemispheres which divided and

covered the entire surface regularly. By 4:00 P. M. each mass

of hemispheres had contracted in width and increased in height;

and the basal part constricted into flutings corresponding to the

surface hemispheres. These flutings gradually contracted to pillars,

the creamy protoplasm withdrawing more and more to the upper

third. In another half hour black stalks were visible as the cores

of the pillars. By 8:30 o'clock all the protoplasm had risen clear

of the substratum and the still cohering heads of the sporangia ap-

peared resting on a forest of black stalks. By 10:00 P. M. the

sporangia had virtually assumed their permanent shape and were

beginning to darken.

A DROUTH-ENDURING ZYGNEMA

Fritsch (Ann. Bot. 1916, pp. 135-149) reports upon a Zygnema

especially adapted to terrestrial conditions. The longitudinal walls

become much thickened, showing two or three successive layers.

The outer layer of the wall is mucilaginous. This doubtless is an

adaptation which prevents too rapid drying and aids resorption of

water on return of moist conditions. It was found on Hindhead

Common (England. )

There are two chloroplasts in the mature cell. Division takes

place by an infolding or growth from the inner layer of the cell wall.

The growth of this gradually constricts the protoplast, but the divi-

sion may not be completed for considerable time. In this way the

two daughter protoplasts have at first a connection thru the center

of this plate.

With the oncoming of drouth the fat globules of the cell pass

to the outer surface, and form there a dense layer just beneath

the cell wall. When the plant begins to absorb water the fat drops

,

190 NOTES, REVIEWS, ETC.

come to be distributed again. When a drouth begins, the proto-

plast develops a new layer of the cell membrane. A cell divides

not more than twice between two drouths. Agamic reproduction

may take place early in the year, by the cell dividing unequally into

a smaller pigment cell and a large, simple reproductive spore

(akinete.) The pigment body disintegrates, the wall weakens and

this becomes a breaking point for the dividing up of the filament.

BACTERIA AID IN FORMATION OF EUROTIUM

Sartory and Roger (C. R. Soc. Biol. Paris; 79: pp. 174-5)

found, in a variety of Aspergillus B grown on damp straw, that they

could secure promptly and abundantly and constantly the forma-

tion of perithecia, provided the culture was innoculated with micro-

organisms of the B. mesentericus group. Otherwise, he found, with

pure cultures of the Aspergillus he could not get the Eurotium even

with the aid of the various media hitherto suggested by students as

valuable in this connection.

BACTERIAL INFECTION IN FRESH EGGS

Hadley and Caldwell (Bul. 164: R. I. State Col. Ag. Exp. Sta.)

have discovered 8.7% of fresh eggs show bacterial infection of the

yolk. The whites were sterile in all cases examined. The fertili-

zation of the egg made no difference in the percentage. Forty dif-

ferent bacterial forms were found. There were no streptococci,

and none of the groups causing hemorrhagic septicemia, enteritis,

typhoid-dysentery, or diphtheria.

The study was instituted to throw light on the mortality of

embryos in incubation, and the degree to which the mortality of

chicks in brooders may be influenced by egg infection from mothers

harboring the germs of diseases.

SOME REMARKABLE FEEDING ACTIONS OF AMEB

Mast and Root (J. Exp. Zool. July, 1916) report studies of the

capture of rotifers, paramecia, and other ciliates, by Ameba. They

capture rotifers by flowing around the foot while attached. The

protoplasm gradually flows upward along the stalk. The rotifer

contracts in the effort to relieve the pressure; but when it extends

AMERICAN MICROSCOPICAL SOCIETY 191

the ameba begins its flow again. In the meantime the rotifer is

gradually weakened by the digestion of the foot. It may require

days to engulf the rotifer.

In the capture of paramecia the amebe take a sort of mush-

room shape. The free margin is made irregular by numerous short

pseudopodia. This furnishes a space beneath the umbrella and re-

cesses at the margin in which paramecia tend to come to rest.

Pseudopodia enclose the paramecia from either side. In some in-

stances pseudopodia reached only about half the length of the

paramecium and by turning toward the body of the prey compressed

it so as to cut the animal in two,—engulfing only the inner half.

This whole process required only about ten seconds. This was not

an isolated incident, but was observed many times.

The writers, by computation based on the amount of pressure

required to cut paramecia with a thin glass thread, have reached the

conclusion that this amputation of paramecia by Ameba could not

be explained by surface tension in the protoplasm of Ameba.

CASE OF BROODING IN HOLOTHURIANS

Ohshima (Ann. Zool. Japon., June, 1916) reports a new case

of internal brooding in holothurians,—Pseudocucumis africanus.

As many as 25 and 27 young were found in the body cavity of the

mother. Three such brood-carrying individuals were found. The

author was unable to discover either how fertilization occurs or the

young escape.

EFFECTS OF ACTIVITY ON NERVE CELLS

Kocher (J. Comp. Neur., June, 1916) after fifteen separate ex-

periments, completely controlled, on six different species of animals,

using cells from various regions of the nervous system, reaches

the conclusion that there is no deviation from the normal, either

qualitative or quantitative, that can be revealed by the most exact-

ing cytological tests in nerve cells even in the most advanced fatigue.

He ascribes the varying results of former investigators to:—(1) dif-

ficulty in separating the effects of normal activity from unavoidable

shock or injury to the nervous system in killing the animal; (2)

post mortem changes taking place before complete fixation; (3)

,

192 NOTES, REVIEWS, ETC.

varying chemical action of fixing agents; (4) solvent action of ma-

terials used in fixation and imbedding; (5) varying effects of chem-

ical reaction between basic or acid stains and the different cell struc-

tures; and (6) effect of subjecting tissues to the temperatures nec-

essary in manipulation. The author used an elaborate series of

checks in control of the studies.

TRYPANSOME INFECTION IN MAMMALS

Lanfranchi (Atti. R. Ac. Linc. 1916, pp. 369-73) believes that

Trypanosoma brucei, T. gambiense and T. vodiense can pass from

the blood of a pregnant mother into the milk; and that by the

first two, at least, the foetus may also be infected in the same way.

IMPROVING TECHNIC FOR SHOWING DETAILS OF DIVIDING CELLS

Allen (Anat. Rec., July, 1916), as the result of a series of crit-

ical experiments to perfect the technic for demonstrating the details

of mitosis in the central nervous system and in the testis of the

albino rat, without producing distortion of adjacent tissues, offers

the following suggestions :—

“For cytological work, the slightest gain at any point in the

technic is worth working for.

“Very gradual changes of fluids, agitation of fluids during

changing, and slow infiltration appear essential in order to get the

best results from any fixative.

“The addition of a low percentage of urea to fixing fluids re-

sults in sharpening the chromosomes and preserving the structure

of the achromatic nuclear material. It may help the penetration of

the fluids.

“Picro-formol-acetic mixtures are more effective when used

at about 38° C. - Cold is detrimental.

“Flemming’s fluid is more effective if used at 0° C. or a few

degrees lower.

“Flemming’s fluid is of no value as a brain fixative at any tem-

perature. At times (if urea is added) it isolates metaphase and

anaphase chromosomes in spermatocytes somewhat better than any

AMERICAN MICROSCOPICAL SOCIETY 193

other fixative tried (except B-15*), but is hard on the rest of the

tissues and shrinks heavily.

“Anilin oil is an excellent substitute for the higher alcohols.

“Xylol shrinks tissues more than the vegetable oils.”

VISUAL EFFICIENCY IN THE USE OF OPTICAL INSTRUMENTS

Purkis (J. R. M. S., June 1916) makes some good practical

working suggestions for those who use the microscope for prolonged

observations, where necessity of accurate observation and minimum

fatigue are necessary.

1. The fact that only one plane is in sharp focus at a time and

that other planes show dimly tempts the novice to strain the eye

in the effort to make it see things which are not clearly in focus,

instead of adjusting the distance.

2. This suggests also that care should first be taken to dis-

cover the limitations of the instrument which cannot be corrected

by manipulation and to accept these, refusing to try to make the eye

compensate for these limitations, by intensely close observation.

3. The eye should look at the field almost casually. What it

cannot see by looking quietly at the object, it cannot see by an intense

and strained gaze.

4. Recognizing that there is a certain amount not only of

shock to the eye in sudden changes from dark to light luminosities

and conversely, but also strain of the eye in the effort to see well

before the re-adjustment is completed, it is important to avoid so

far as possible sudden changes of luminosity. In this connection

it is well (a) to see that the illumination of the room is not in too

great contrast with that of the instrument; (b) to modify luminosity

to compensate when passing from one objective to another; (c)

to avoid sharp contrasts of luminosity within the field itself; and

(d) when resting the eye preparatory to observation or during ob-

servation to do so in approximately the same illumination to be used

in the field of the instrument.

*B-15 is a picro-formol chrome-acetic mixture in urea:

Picrigiacideyysiceylecrete oe acon 75cc

Pormolaerene cece eke 25cc

ACetievaciducnnehiccisia/seeisices 5ce

194 NOTES, REVIEWS, ETC.

NORTH AMERICAN DIATOMACEZ:

A new guide for the American student of Diatoms will be of

interest to many members of the American Microscopical Society.

Charles S. Boyer has issued a monograph of most painstaking char-

acter on the Diatomaceze of Philadelphia and vicinity. The book

opens with an introduction descriptive of the physical condition of

the Philadelphia region,—which means a territory with a radius of

about 100 miles from Philadelphia. A short chapter is devoted to

the structure, reproduction, evolution, and rdle in nature of the

diatoms.

The body of the book is igven to keys, descriptions, and figures

of nearly 600 species and varieties. There are 700 drawings by

the author illustrating these species. All these drawings are to

uniform scale,—about 800 diameters. In his classification the

author adopts Schuett’s synthesis of the various bases of classifica-

tion of Pfitzer and Petit, Smith, Mereschkowsky, as well as the

older methods. The synonymy is for the most part omitted.

The appendix contains suggestions as to the collection and prep-

aration of diatoms for mounting and study. Many of these will

prove most helpful for the inexperienced student of the group.

The headings :—Collection of fresh water material; Collection of

marine material; Blue clay deposit ; Cleaning material; Preparation

of strewn mounts; Preparation of selected mounts; Instruments re-

quired,—will sufficiently indicate the scope of these hints. Mechan-

ically the book is very attractive. It is bound in art vellum cloth,

the pages are 9x12, and the text is printed on heavy unglazed paper.

The Diatoms of Philadelphia and Vicinity, by Charles S. Boyer, A.M., F.R.M.S.,

143 pages, 700 illustrations. J. B. Lippincott Company, Philadelphia, Pa., 1916. Price

$5.00.

NECROLOGY

Burrill, Thomas J, Ph.D. ’78, President A.M.S.,

1885: ans POOR oe a ee Urbana, Il.

Mewis. Dea Wi Oe ilsecee «aes gre ie Dixon, Ill.

IRA W. LEWIS

Mr. Lewis, who was for nearly twenty years a member of the

American Microscopical Society, died May 26, 1915, at the age of

73. He was a man of most substantial character and attainments.

For 45 years he was connected with the office of the Clerk of the

Circuit Court of Lee County, IIL, as Deputy or as Circuit Clerk.

The Bar Association of the County testified in a public Memorial

Service to his unvarying efficiency and high mindedness.

He was a devoted churchman and gave much of his energy to

work in the moral and religious education of youth. He was a

self cultured man, and his memorialists testify with great uniform-

ity that he was one of the most remarkable and versatile men of his

community.

In the meantime he gained local note as a student of books and

of nature. He was very devoted to his work with the microscope and

collected an extensive library of microscopical journals and sci-

entific books. It would be greatly to the credit of American culture

if we had more such amateur students with the microscope.

His wife survives him.

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TRANSACTIONS

_ OF THE

American Microscopical

Society

ORGANIZED 1878 INCORPORATED 1891

PUBLISHED QUARTERLY

BY THE SOCIETY

EDITED BY THE SECRETARY

VOLUME XXXV__

NuMBER Four

Entered as Second-class Matter December 12, 1910, at the Post-office at Decatur,

Illinois, under act of March 3, 1879.

Decatur, ILL.

Review Printinc & STATIONERY Co.

1916

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cei

ta By

Ser }

aa

8 f a

OFFICERS

Peer WE. E GUVER< «is.s/c dibejaielatisvaetdtanio nae aia ai gieielaeisieua Madison, Wis.

Forst Vice President: T. L. HANKINSON.........cccccccscccs Charleston, IIl.

Second Vice President: L. E. GRIFFIN. ....cccsscccccnccceces Pittsburg, Pa.

meercnarve’ LT. W. GALLOWAY Snes cuca duaesewauedemeweaisn sense t Beloit, Wis.

eareuney:.: T1. J. VANCLEANS, wecicaa page whee cada ieeaibestn se katt Urbana, Iil.

Eecrontan: MAGNUS PFLAUM o cis aos sess dashes eds clddens «ea bape Meadville, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE

TEROHGE) Its TEARUE s/s siteaie tote 20 falsinig oe bisiee hele tletatelntcctorste ssiate Ann Arbor, Mich.

HAMS SESRODE & occ o Sie Sune brsteie alee eo Waeic ela gait tabe « wiccmon Walla Walla, Wash.

EX-OFFICIO MEMBERS OF THE EXECUTIVE COMMITTEE

Past Presidents Still Retaining Membership in Society

R. H. Warp, M.D., F.R.M.S., of Troy, N. Y.,

at Indianapolis, Ind., 1878, and at Buffalo, N. Y., 1879

Apert McCatra, Ph.D., of Chicago, IIl.

at Chicago, Ill., 1883

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

at Detroit, Mich., 1890

Simon Henry Gace, B.S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895 and 1906

A. Ciirrorp Mercer, M.D., F.R.M.S., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896

A. M. Breire, M.D., of Columbus, Ohio,

at New York City, 1900

C. H. E1icenmann, Ph.D., of Bloomington, Ind.,

at Denver, Colo., 1901

E. A. Brrce, LL.D., of Madison, Wis.

at Winona Lake, Ind., 1903

Henry B. Warp, A.M., Ph.D., of Urbana, III,

at Sandusky, Ohio, 1905

HERBERT Oszorn, M.S., of Columbus, Ohio,

at Minneapolis, Minn., 1910

A. E. Hertzier, M.D., of Kansas City, Mo.,

at Washington, D. C., 1911

F. D. Heap, Ph.D., of Philadelphia, Pa.,

at Cleveland, Ohio, 1912

Cares Brooxover, Pu. D., of Little Rock, Ark.

at Philadelphia, Pa., 1914

Cuartes A. Koroip, Ph.D., of Berkeley, Calif.,

at Columbus, Ohio, 1915

The Society does not hold itself responsible for the opinions expressed

by members in its published Transactions unless endorsed by special vote.

TABLE OF CONTENTS

FOR VOLUME XXXV, Number 4, October, 1916

Report of the Secretary-Editor, by T. W. Galloway.................... 201

A Comparative Study of Epigyny in Certain Monocotyledons and Di-

cotyledons, with Plates XX VIII-XXXVI, by Margaret Hannah.... 207

Acanthocephala of the Genera Centrorhynchus and Mediorhynchus

(new Genus) from’ North American Birds, XXXVII-XXXIX, by

BR Jz) Vai" Gleave? ).6 2 x cin hata ns iced oe kai Oe Gates ere ee 221

The Genus Aspidisca Ehrenberg, with 15 Text Figures, by Harold H.

Pefo uate hs Meo eiai es 2d heating nah as Ula a ea halide tntahclorehe et pack at ean 233

Nematode Technique, with 6 Text Figures, by Thomas Byrd Magath.... 245

Notes and Reviews: Entomological Notes, by Pauls S. Welch.......... 257

Necrology::) Thomas J: Barrill’ 5) 50/)/68 css dae seceieiste sie ee mcs soe tuaeremies 269

Llist OE MGI ADOT hee) Uo ate asclese Utes nye elon oo le et oa pb a ere 271

PASE GE VSGUSCOIDEN SY), Je 361) aa ais sn destde wee Woetoeieye 2 GA ee eee eens En 280

BBE tdi ota in pha winds wea wi Abe ol © bints Aigie le telee AMMA bh eid No were Sega ene a 283

Notice TO MEMBERS

Business Sessions of the American Microscopical Society will

be held at New York City, as follows:

Dec. 28 (Thursday), 8:15 A. M., Executive Committee will

meet at breakfast at Hotel Martinique.

Dec. 28, 4:30 P. M., General business meeting of the Society,

immediately following the adjournment of the American

Society of Zoologists, in the Hall used by them.

The Headquarters of the American Microscopical Soctety will

be the Hotel Martinique, Broadway, 32-33d Sts. It is convenient—

near the Pennsylvania Station—and reasonable in rates.

T. W. Gatitoway, Secretary,

Beloit, Wisconsin.

(This Number was issued on December 16, 1916.)

TRANSACTIONS

American Microscopical Society

(Published in Quarterly Installments)

Vol. XXXV OCTOBER, 1916 No. 4

2 ST SS ee SE eee

REPORT OF THE SECRETARY AND EDITOR

T. W. GALLoway

Beloit College, Beloit, Wis.

Three years ago the Secretary reported to the Society the out-

standing facts relative to the state of the organization during the

first term of his service. The present number marks the close of

the second term of three years. In the absence of large and well

attended meetings of the members, where discussions both of scien-

tific and business details would place in the minutes much that

would enlighten the members as to the work of the Society, it

appears that a triennial report by the Secretary may well supple-

ment the annual reports of the Treasurer and the Custodian.

It seems necessary, for the sake of efficiency in such a Society,

that a large amount of the leadership and decision of policies fall

upon the Secretary. The organization pays for this freedom of

action on his part, however, in a certain loss of responsibility and

mutuality on the part of the membership. The Secretary feels

very strongly the lack of positive and constructive,—or for that

matter any kind of,—criticism.

Attention was recalled in the last report to the transitional

period through which the Society has passed in the last quarter of

a century, and to the decision four years ago to try to find a func-

tion for the Society which would be at once worthy of its best

traditions and place it in a position in which it may continue, in

spite of the multiplication of special societies, to serve American

science and scientists. It is too much to hope that this has been

done as well as it might have been done. Yet evidences are not

wanting that the policy adopted then has been on the whole well

chosen.

202 T. W. GALLOWAY