TABLE OF CONTENTS

FOR VOLUME XXXVIII, Number 1, 1919

Illustrating Biological Manuscripts, with Plates I to V, by E. A. Smith.......00000000.......

The Occurrence of Trypanoplasma as an Ectoparasite, with Plate VI, by Olive

Notes and Reviews: The new Treasurer; Problems of the Future; Crystals in

Amebas; Montana Trematodes; The crystalline Style of Lamellibranchs;

Revivification of Earthworms; Life Behavior of Ascaris, Reversal of Orienta-

tion to light; Reactions of land Isopods to Light; Adaptive Coloration of

Chromodoris zebra; Camouflage in Reef Fishes; Glycogen in the nervous

System; Effect of Strain on Development of Bone; Epithelial Movements

in vitro; Entomological Abstracts; A convenient Slide Holder; Notes on

Technique; Measuring Carbon Dioxide Produced by Protozoa; Method for

Demonstrating Glycogen in Tissues

OFFICERS

President 2 %a2 TEs! GRUB RING 5. 15S sors sed ccccacavess ees ces een noon Oonce ae aewsegeptcctaecieere Pittsburg, Pa.

Birst Vace President : Hc Mi. \WHELPUE 6 cestscne tacos ececteeacetetese-cetecensestesstea St. Louis, Mo.

Second Vice-President: (CO VESTERE Vere coe te ere ec eee cer reece ees Los Angeles, Cal.

Secretary: T.. W. GALLOWAY .o:0 Soo is ares soreweenecepon sous tac ossnpebespowossusesonsecacsadonnuianes Beloit, Wis.

TP CGSUrer:. WV ELLIAM. EEE NDERS ON: ree secctecesrercecuceeee set tsee corse castosctee stenonte setae Decatur, Ill.

Custodian:) NMUAGNUS (PERAUMie ceo ccestcceates voces itses ease xeevenenede ensue cnstensorseetsese Meadville, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE

IVES EVE BV ETS 50 S00 Bead eer Pe les ae, ads User cea sab stbe ctetats beak cates aes Soros Boulder, Colo.

fic Ess fA CRED ee aA a Ht seed ee Nea ce supe cee oniel taeaeedd cy cub ade srs seapecessenss Manhattan, Kas.

EX-OFFICIO MEMBERS OF THE EXECUTIVE COMMITTEE

Past Presidents Still Retaining Membership in the Society

Smon Henry GAcgE, B.S., of Ithaca, N.Y.,

at Ithaca, N. Y., 1895 and 1906

A.CLIFFORD 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. EIGENMANN, Ph.D., of Bloomington, Ind.,

at Denver, Colo., 1901

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

at Winona Lake, Ind., 1903

Hnery B. Warp, A.M., Ph.D., of Urbana, III.,

at Sandusky, Ohio, 1905

HERBERT Osporwn, M.S., of Columbus, Ohio,

at Minneapolis, Minn., 1910

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

at Washington, D. C., 1911

F. D. HEALD, Ph.D., of Pullman, Wash.

at Cleveland, Ohio, 1912

CHARLES BROOKOVER, Ph.D., of Louisville, Ky.,

at Philadelphia, Pa., 1914

CHar_es A. Koro, Ph.D., of Berkeley, Calif.,

at Columbus, Ohio, 1915

M. F. Guyver, Ph.D., of Madison, Wis.,

at Pittsburg, Pa., 1917

The Society does not hold itself responsible for the opinions expressed

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

TRANSACTIONS

American Microscopical Society

(Published in Quarterly Instalments)

Vol. XXXVITT JANUARY, 1919 No. 1

TS SPSS 2 es iad) OIE A AE CEE Sha SE

ILLUSTRATING BIOLOGICAL MANUSCRIPTS

By E. A. Smith

Learn drawing—‘“‘that you may set down clearly and usefully,

records of such things as cannot be described in words, either to assist

your own memory of them, or to convey distinct ideas of them to other

people.” Ruskin.

Although many excellent books have been published concerning

drawings and the processes involved in reproducing them, a beginner

in science can consume hours in attempting to find within their covers

the kind of information he desires. The books on drawing are

usually written for artists who desire effect and not scientific accuracy,

and those that deal with methods of reproduction serve as text-books

for journeymen interested in the commercial phases of the work.

In this article, therefore, an attempt will be made to set forth simply

and concretely what points should be considered in making a draw-

ing; to tell which media are best for certain classes of work; to give

some idea of how the drawings are reproduced, together with the

limitations imposed by photo-mechanical methods.

A black picture on a white background gives the best contrast

for reproduction. In numerous subjects the form and texture can be

brought out equally well in black ink, in crayon, in water-color, or a

combination of these. One of these media may show the points

which need emphasis better than another. Therefore, before mak-

ing drawings for a paper, an author should study the illustrations in

the journal in which he expects to publish and select the style best

suited to his subject. Skill may well be considered also, as a simple

outline in ink is preferable to an elaborate picture poorly executed.

Manuscripts which contain drawings that can be reproduced as line

or half-tone engravings are more readily accepted by editors as they

can be published with less expense. The extra cost of plates requir-

ing lithography, heliotypy, or photogravure sometimes must be paid

by the author.

2 SMITH

I. METHODS OF ILLUSTRATION

This is no place to enter into the history of graphic reproduction,

interesting as it is, nor to describe all the processes in commercial

use to-day. Processes available for reproduction may be divided into

three distinct groups: (1) intaglio; (2) planographic; and (3) relief.

Intaglio

The intaglio processes include all those in which the impression

is printed from incised or depressed surfaces. Engraving, the oldest

known of these methods, consists of lines cut by hand into a copper

or steel plate with a graver. On account of its cost, it is seldom used

except by the government where it is employed in the making of

plates for paper money and maps, as many copies may be printed

without injuring the plate.

Planogra phic

Planographic methods include Lithography, Photolithography,

and Photogelatin or Heliotype, in which printing is done from a flat

surface. In all these, the surfaces are so treated that certain parts

repel ink while other parts take it.

Lithography. In Lithography advantage is taken of the fact that

grease unites with limestone to form a substance insoluble in water.

Zinc and aluminum plates may be substituted for the stone, using

practically the same procedure. The picture to be reproduced may

be drawn in reverse order upon a smooth, flat piece of limestone with

a special ink or chalk composed of wax, shellac, tallow, and soap.

For a shaded, scientific drawing, the surface of the stone is grained,

either a fine or coarse grain, depending upon the effect desired.

Instead of drawing directly upon stone, the picture may be drawn in

proper position upon a smooth or grained paper with lithographic

chalk, as itis then reversed when transferred to the stone. To transfer,

the paper is dampened and placed upon the warmed stone, then both

are run through a press. Considerable skill is required in making

scientific drawings upon grained transfer paper as a smudge results

in the transfer if the chalk is too soft or the lines too heavy. On the

other hand, if the lines are too light, the transfer is blotchy. Some-

times a thin, gelatine sheet is placed directly over a drawing, every

detail of which is outlined on the gelatin with a fine etching point.

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 3

After ink is rubbed into the lines, the gelatine is dampened and a

transfer made upon stone.

Dilute nitric acid applied to the surface attacks the parts of the

stone free from ink, producing a chemical change so that the gum

arabic solution next put on renders the surface grease-resisting.

For chalk work an equal mixture of gum and nitric acid is added.

More than one acid bath and several coats of gum may be given in

preparing the surface. Often powdered rosin or asphaltum is dusted

over the surface. It adheres to the ink, thus protecting it from the

acid.

Before a print is taken from the stone, the gum is washed off,

leaving the etched parts wet. These, then, repel the printing ink.

The latter adheres to those parts of the stone covered with litho-

graphic ink or chalk. The clearness of the print depends to a large

extent upon the skill of the operator.

Photolithography. In Photolithography, the picture is photo-

graphed and from the negative thus obtained, a print is made upon

paper coated with bichromatized gelatine. The picture to be used

for the illustration is placed in front of a camera which contains a

piece of glass coated with a film of gelatine or collodion mixed with

a salt sensitive to light—a photographic plate. When the camera

shutter is opened the white parts of the picture reflect light upon the

plate and cause a chemical change. The dark parts of the picture

have little or no effect upon the salt. Colors reflect light in varying

degrees, thereby modifying the plate. The plate is next treated with

the chemicals which cause the parts unaffected by light to wash out

while the other parts become opaque. A negative is thus produced

in which the light parts of the picture are opaque and the black parts

clear. If this negative does not present enough contrast between the

opaque and clear parts, it is put into a solution which makes the

opaque areas denser.

From the negative, a print is made upon transfer paper first

coated with gelatine and then immersed in bi-chromate of potash

and dried in the dark. The negative is placed upon the coated side

of the paper and both are exposed to light in a printing frame. Gela-

tines, gums and other organic compounds when sensitized with cer-

tain chromic salts are rendered insoluble wherever exposed to the

action of light rays. The gelatine protected by the opaque parts of

4 SMITH

the negative are still soluble whereas that under the clear spaces is

made insoluble by the light. The print when sufficiently exposed is

taken out and covered with ink. It is now placed in cold water which

causes the gelatin surface to swell in the soluble spaces. When

rubbed over with a sponge, the ink comes away from all parts not

affected by light, leaving a print of the picture in ink slightly in

intaglio. This is then transferred to stone which is prepared as for

any lithograph.

Heliotype. A negative and print are madein the same manner as

described above, except that the negative is reversed before it is

printed and the gelatine coating on paper or glass is thick enough to

be detached from its original support and printed from directly

instead of transferring it toa stone. The gelatine acted upon by light

takes ink, the other parts absorb water and repel the ink.

Relief

In the photo-mechanical processes such as zinc-process and half-

tone, the plate is so treated that the picture remains in relief upon a

sunken background.

Zinc-process. From the negative, a print is made upon a piece of

polished zinc which has been coated with a sensitized substance such

as a mixture of egg-white, fish glue and ammonium bichromate. The

negative is placed upon the coated side of the zinc and both are

exposed to light in a printing frame. Instead of developing as a

photographic plate, the zinc is covered with an even coating of

special ink put on with a roller—‘“‘rolled up,”’ is the printer’s phrase.

This ink is rather thick and contains wax and tallow to make it

greasy. When the inked plate is placed in water, the parts of the

coating not affected by light wash away, leaving the image in black

lines upon a metal background.

The plate is now covered or powdered up with a red, resinous

powder called dragon’s-blood. This powder is obtained from any one

of several different kinds of tropical trees. Upon warming the plate

the powder unites with the ink and makes it more resistant to acid.

After painting the back with a varnish, the plate is put into nitric

acid which acts upon the uninked and unvarnished zinc surface.

Usually the plate is sufficiently etched after four treatments in the

etching bath so that the image stands up in relief upon the metal

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 5

surface. When finished the thin metal plate is mounted upon a

block, type-high. Cuts of this kind can be printed as text-figures if

the details are not so fine that a slight spreading of ink in printing will

destroy the contrast.

Half-tone. In this process a screen is placed between the camera

and picture before the negative is made. This screen usually consists

of two glass plates, each engraved with lines an equal distance apart

which are filled with an opaque black substance. The plates are

cemented together in such fashion that the lines cross at an angle.

The number of lines per inch vary from 50 to 400 and the crossing

may be at various angles. For microscopic enlargements 200 to 250

lines per inch are used and the plates are fastened together so that

the lines cross at an angle of 45°. When a picture is photographed

through the screen, the negative is covered with small dots the shape

of which depends upon the camera diaphram. The contrast of the

original picture is lessened since the white parts are covered by black

dots and the black areas by white dots.

If a coarse screen is used the negative can be printed upon coated

zinc and etched as for zinc-process. A coated copper plate is neces-

sary where the dots are fine. After the copper plate has been exposed

under the negative it is heated until the sensitized coating turns

brown where it has been affected by light. This brown oxidation

product is insoluble in water and acids. The plate is now etched in a

solution of perchlorid of iron until the picture stands out in relief.

If clear white spaces are desired in the print, the dots produced by

the screen must be tooled out of the plate in these places. As this

is done by hand, it adds to the expense of the plates. Prints may be

made directly from the plate which has been backed with base metal

or wood, or electrotypes may be made from the original.

In printing there is an increase in the size of the black dots and a

decrease in size of the white dots due to the spreading action of the

ink. If the block is printed on a coated paper, this spreading action

is reduced somewhat and can be overcome through the use of an over-

lay, which is a pad placed on the roller.

Various modifications of the half-tone process are obtainable

through the use of different screens—such as mezograph, but the

principles involved are the same.

6 SMITH

II. DRAWING FOR PUBLICATION

Outline

In free-hand drawing of objects, care must be taken to get a prop-

erly proportioned outline. First, determine the size the drawing

should be. A small object can be represented several times natural

size whereas a large one needs reduction. Upon two faint lines which

cross at right angles in the middle of the field, indicate by dots the

length and breadth of the object. Other important points can also be

marked with dots which, when connected with light lines, roughly

block in the object. For this preliminary mapping, an HB pencil

lightly clasped between first finger and thumb, and resting on the

second finger, should be held in such a manner that the side of the

lead comes in contact with the paper at a small angle. Lines thus

made can be easily erased as the surface of the paper is not injured

by the lead. This crude picture can now be worked over until the

finished outline consists of a continuous line of uniform thickness with

no overlapping edges where the pencil has been removed from the

paper and put down again. The pencil lines should be removed with

an art gum eraser until the outline remains only as a faint impression

which must be gone over again with the pencil. If guide lines and dots

are drawn in light blue, they do not need to be erased since pale blue

photographs as white in the reproduction of the picture. In picturing

microscopic sections and objects, a correct outline is easily obtained

by tracing around the image projected upon the drawing-paper by a

camera lucida.

Pers pective

Perspective, a subject which can not be treated in any great detail

here, must be considered in drawings in which three dimensions are

depicted. Objects should be drawn as they appear to the eye and not

as they are known to be. They present their true appearance only

on that side parallel to the eye. The apparent change in shape which

takes place when an object is situated at an angle to the eye is known

as foreshortening.

Since drawings of tubes and cylindrical objects are frequently

made in biological papers, an understanding of a few principles of the

perspective of a cylinder is necessary. If an ordinary tumbler is

raised, the visible top becomes narrower and narrower until it appears

as a straight line when directly opposite the eye—or at eye-level, as

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 7

it is technically called. When the tumbler is lowered from eye-level,

the top, though actually round, first appears as an ellipse. Moreover,

this ellipse is narrower than that formed by the round bottom, for the

latter is farther below the eye-level (Fig. 1). In drawing a tube, the

eye-leve |—_—_—____——————

Figure 1. Three cylinders drawn to show the appearance of the top and bottom

at different distances below eye-level. Reproduced 1% originai size by zinc-process.

bottom edge will be more curved than the top as it represents one

side of an ellipse broader than the one at the top (Fig. 2).

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artery sy

Figure 2. Diagram to show relation of Malpighian body and uriniferous tubules

to the blood vessels. Reproduced 4% original size by zinc-process. Taken from Labora-

tory Directions by M. F. Guyer. Labels typed and pasted on drawing.

8 SMITH

It is a familiar fact that from the rear coach of a train the rails of

a straight piece of track converge toward a point in the distance

directly in front of the eye. If all the outlines of a building seen

through a window should be traced on the pane, they would converge

so that if continued they would meet at two or more points. Like-

wise, if a book is placed horizontally in front of the eye, the parallel

lines which represent the sidesappear nearer together at the back than

in the front, and if continued would meet at a point directly in front

of the eye. This point is spoken of as the vanishing point.

If the book is moved so that the front edge is no longer parallel

to the eye, the vanishing point changes, and instead of one point

there are now two, one on either side of the object. These points,

however, are on an invisible line which runs at the eye-level. Study

the illustration (Fig. 3) to see how the lines vanish. All lines of the

object that are parallel vanish to the same point. If two books do

not lie at the same angle there will be four vanishing points, two for

each book, but these points all lie on the line drawn at the eye-level.

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Figure 3. Diagram to explain parallel and angular perspective. The printed

letters cut out and pasted on the drawing are too small for the reduction used. Re-

produced 14 original size from a zinc plate.

Shading

Often form can be rendered more aptly by the use of light and

shade (PlateI). Objects exposed to direct light generally appear

lighter on the side near the source of light and darker on the other

side. Furthermore, the shadow cast by the object is always darker

Plate I. Crayon drawing illustrating shading on plane, convex and concave sur-

faces. From a half-tone cut 14 the size of the original. Made with a screen containing

150 meshes per inch.

PLATE I

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

SMITH

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 9

than the shaded side of the object itself. In the zone between the

lightest and darkest part of the object, the half-light or half-zone,

details are most prominent. To indicate all the variations in shade

would complicate the drawing unduly, hence it is the practice to use

only those shadows which are necessary to bring out the form of the

object disregarding all others.

Likewise, color, texture, and shape of the surface can be expressed

through the proper placing of shadows. Shadows upon different

colored surfaces have different values since colors vary in the way in

which they reflect light. This is easily illustrated in photographs

where a yellow surface takes dark, red shows up as black, and blue

comes out white. Also the nature of shadows differ on shiny and on

dull surfaces.

A flat surface usually has a continuous shadow of even tone,

whereas on a curved surface the shadow must grade off into darkness

on one side and into light on the other, with no sharp edges defining

it. On a concave surface, the sunken appearance is produced by

placing the darkest tone nearest the source of light, shading to a

lighter tone away from the light. For here, the higher edge around

the concavity prevents the light from striking the side nearest it.

Convex surfaces, on the other hand, are illuminated on the side

toward the light while the elevated center keeps the light from the

opposite side.

Drawing

Ink Drawings. Pen drawings reproduce well by the zinc-process

method as the black absorbs all light and the white back-ground

reflects all, thereby producing great contrast in the negative.

For ink-drawings a good water-proof India ink such as Higgins’

should be applied with pen or brush upon bristol-board (2 or 4 ply),

upon Whatman’s hot-pressed (smooth) water-color paper, or upon

ledger paper. Whatman’s paper is the same texture throughout;

moreover, it can be used for wash or ink-work. Ledger paper,

while little known, is excellent as erasure will not damage the surface.

Gillott’s pen points are satisfactory but inasmuch as each person

handles a pen differently, exerting varying degrees of pressure in

drawing, one number may not suit all workers. For fine line work

and stippling, lithographic pen No. 290 is good. Fine red sable

10 SMITH

brushes can be used although the pen drawing is likely to prove more

successful.

After the pencil outline is correct, the drawing is ready for ink.

On a clean pen-point place the ink by means of the quill attached to

the cork of the ink bottle. A ragged line results if the pen is held so

that one nib bears more heavily upon the paper than does the other,

or if it becomes sticky with dried ink. To secure a line of uniform

thickness the pen should be held at a wide angle to the paper so that

only the very point touches, and a firm steady pressure be applied.

Figure 4. The fur is suggested by the use of uneven lines. Reduced 14 and repro-

duced from a zinc plate.

While ink thinned to a gray gives a difference in tone in the original

drawing, in reproduction gray lines may behave erratically, often

appearing as broken black lines. To avoid graying black lines the

pen must be wiped frequently and refilled.

Effects may be obtained by the use of lines alone, either by vary-

ing the thickness of the lines or the distance between them. How-

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

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PLATE II

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 11

ever, extremely fine lines may break, whereas coarse lines when placed

close together tend to merge. Lines in the foreground should be

heavier and farther apart than those in the background. Lines should

follow the shape of the shadows, but they should end unevenly to

avoid stiffness. In the darkest areas lines may be placed in an oppo-

site direction across the first set.

Plate II is an ink-drawing in which the background and part of the

cavities were inked, leaving the picture in white. This is an excellent

method to follow in diagrams as the chief parts are strongly empha-

sized.

Texture and surfaces can be expressed by the use of lines of

different character. Thus broken lines and dots indicate fur (Fig. 4),

while fine, smooth lines may suggest feathers. Short, uneven lines

in the depressions, suggest rough surfaces, while a few parallel lines

on the heavily shaded areas are necessary for a smooth surface.

Figure 5. Ovary of frogin stippledink. This drawing required much more time

in its execution than A and B of Plate V. It was reproduced by zinc-process with same

reduction as Figure 10.

Although bold line-drawing is admirable for some things, subjects

often require the reproduction of the half-lights. These can be sug-

gested by dots in a pen drawing (Fig. 5). All dots must be round

and of the same size. Round dots are made by grasping the pen

firmly and holding it in such manner that it meets the paper squarely.

If it strikes at an acute angle, three-sided instead of round dots will

result. Heavy shading is indicated by placing dots close together;

light shading, by keeping them farther apart. Dots that are too fine

Plate IJ. Diagram of pig embryo surrounded by membranes. Lettering done by

hand in white ink. Printed from a zinc plate 14 the original size.

12 SMITH

can not be reproduced on zinc as the acid undercuts the sides of the

dots, thus destroying the stippled effect.

Slight irregularities and defects are easily removed from the

drawing by scraping them away or covering them up with Chinese

white paint. Before applying white paint clean away all pencil

marks and completely cover the part to be obliterated with several

coats if necessary. Alternations are then made as desired since the

white paint does not interfere with inking. Only a little ink should

be placed on the pen when attempting to re-ink a spot erased with a

knife as the ink spreads on the damaged surface.

Wash drawings. Wash drawings are ordinarily reproduced by

half-tone process. The contrast between the black and white parts

of the original picture should be exaggerated, as the screen inter-

sperses white dots in the black areas and black dots in the white

spaces thereby lessening the contrast of the picture.

For wash-drawings, Whatman’s paper mentioned previously, or

any smooth water-color paper, will prove satisfactory. A grained or

rough surface usually causes unpleasant effects. Winsor and New-

ton’s Ivory Black or Charcoal Grey makes a good working medium.

These colors come in solid cakes from which the wash is prepared as

follows: With a wet brush remove some pigment from the cake and

put in water in a mixing pan. Repeat this process until the wash is

slightly darker than the desired background as the tint lightens in

drying. Good sable brushes keep their shape if they are washed after

using, brought to a point, and kept inverted in a jar.

Although from the artistic standpoint the use of the brush alone

is preferable, the accuracy demanded in a scientific drawing makes a

faint pencil outline more practical; and a hard pencil is better than a

soft one if the surface of the paper is not injured with pressure, as the

graphite is not so likely to smear when wet. After the outline is

finished, the paper should be fastened to a board with thumb tacks

and the entire surface dampened with a large brush, removing the

surplus water with brush or blotter. If the picture is large or com-

plex a dampened blotter placed under the paper will keep the surface

moist for a long period. The wash is applied over the entire back-

ground and the paper allowed to dry partly before darker tones are

added. Where a very dark portion is confined to a small area, the

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

XXVIII

VOL. X.

SOCIETY,

SMITH

PLATE III

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 13

paper should be quite dry, otherwise the wash will run into the sur-

rounding part. With wash alone, good effects may be obtained

(Plate III, C). Details may be stippled either in wash or in ink or

drawn in with lines.

Where several wash-drawings require the same tones, it will be

found simpler to put in all the backgrounds first. Mix up plenty

of wash for this purpose, as it is not easy to duplicate the exact shade.

Wash allowed to stand becomes darker upon evaporation of the water;

hence if, after the backgrounds are put in, the work must be deferred

until later, the same wash will do for darker tints. When the work

is continued it is not necessary to redampen the entire surface as the

dark tones can be blended into the background with a clean, wet

brush.

Some artists prefer a dry paper but this requires more skill in

applying the wash. For, unless the work is done rapidly, the pigment

dries leaving a dark line or water-mark where each brushful of wash

ended.

With an air-brush beautiful wash-drawings can be turned out in

a short time. The wash is placed ina receptacle and by air-pressure

sprayed over the parts of the drawing in a fine stream. Considerable

skill is necessary in regulating the spray. Moreover, the instrument

is expensive and requires an air-gage and cylinder. But if the brush

is at hand it will repay the time spent in learning its use, especially if

one contemplates making many drawings.

Crayon. With crayons, drawings scientifically accurate and artis-

tic as well are obtained with least expenditure of energy. Moreover,

mistakes due to lack of skill in execution are more readily remedied.

While Conte crayons in pencil-form come in five numbers ranging

from hard to soft, No. 2issuitable for most work. Varied stipple effects

may be produced by using them upon Ross stipple board. This paper

has a grained chalk surface to which the crayon adheres in the form

of dots when it is rubbed back and forth over the chalk. The grain

of the paper differs in the different numbers. No. 8 is good for general

Plate III, A. Reproduction of a photograph by the half-tone process. No reduction.

B. Crayon drawing of embryonic vesicle of young human embryo re-

produced 1% size of the original by half-tone process.

C. A half-tone reproduction of a rabbit embryo in the uterus made from

wash original reduced 14.

14 SMITH

work. The edges of such a drawing may be cleaned up or straightened

by scraping off the chalk surface, thus revealing the white paper below.

Dot or line crayon-drawings may be satisfactorily reproduced by

zinc-process if the drawings are coarse enough to stand a reduction

to one-half their original size. Here as in ink drawings, brown

lines are apt to break.

Crayon-drawings closely resembling wash-drawings in appearance

may be made. For the ground-coat lightly rub the crayon over the

paper and then with a stub blend the crayon marks into an even

coating. In the following manner a paper stub is made from a strip

of uncoated paper 1 inch wide and 5 inches long: Begin to roll the

paper at one end and let each turn overlap the preceding turn slightly,

until an elongated coil results. Paper or chamois stubs ordinarily

used for charcoal work may be used for crayon. Details are put in

with lines or dots of crayon. Where white spaces or high-lights occur,

the ground-coat may be removed with an eraser cut to a fine point.

If much white occurs, it is better to put in the details first and then

use a stub on parts which need shading. Dark parts can be accen-

tuated with ink. (Plale III, B).

White crayon on gray or black board makes an effective illustra-

tion especially for transparent objects such as medusae or for

membranes (Plate IV).

Pencil drawings. While pencil-drawings permit of subtle differ-

entiation in detail, in making they consume an amount of time out of

all proportion to the effect obtained. MHalf-tone reproductions of

pencil-work not only are inferior to the originals, but do not begin

to compare with half-tones obtained from wash or crayon-drawings.

Good illustrations may be secured from pencil-drawings reproduced

by lithography. The expense involved from such reproduction

makes them undesirable for scientific purposes if any other method

will do.

Either dots, lines, blended graphite, or a combination of these may

give results desired in pencil-drawings. In stippling with a pencil,

the point should be sharp and rounded on all sides. With an HB or

2B pencil graphite is sometimes placed on the part of the drawing

Plate [V. Series of drawings to show developing starfish egg. Original made in

black and white crayon on dark gray background. Reproduced by half-tone 4% the

original size.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIITI

PLATE IV SMITH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

SMITH

PLATE V

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 15

where the darkest shadows occur and then worked over with a stub

in the same manner indicated under Crayon. Plate V contrasts a

half-tone made in pencil, wash, and crayon. Compare with Fig. 5.

Fixing Pencil and Crayon Drawings. Pencil and crayon drawings

which are likely to rub must be fixed. A fixing solution is sprayed on

the drawing with a special atomizer which can be bought at any art

store. To prepare the fixative, make a saturated solution of white

shellac in alcohol; allow this to stand for a day or so; dilute one-half;

then filter off the liquid. To prevent evaporation, this should be kept

in a tightly stoppered bottle when not in use.

The drawing is placed in an upright position, about two feet from

the spray. To avoid a glossy surface, only a light coating of fixative

should cover the picture.

Combinations. Any combination of wash, crayon or ink is allow-

able so long as the picture retains sufficient contrast to reproduce

well. Ink and wash are effectively used in Plate V, A. Where ink is

combined with wash, lines and solid black areas are broken up by the

screen in the half-toning. Only by printing from a zinc-plate over

the half-tone print can definite lines or black areas be indicated.

The same applies to ink used with crayon if the picture is half-toned.

Methods for Special Subjects. Upon a survey of the leading

journals certain methods were more often used for special subjects,

tho departures from those indicated in the following table were

common.

Subject Method Process

1. Cell structure Stippled ink Zinc-process

2. Protozoa Stippled ink Zinc-process

3. Animals of phyla Stippled ink or line —Zinc-process

4. Histological slides Wash or Half-tone

Wash and Ink

5. Embryological slides Wash or Half-tone

Wash and Ink

6. Whole embryos Crayon or Wash Half-tone

7. Dissections and anatomical subjects Crayon or Wash Half-tone

Plate V. Section of ovary of frog drawn in (A) wash with details in ink, (B)

crayon, (C) pencil. Reproduced in halftone 24 size of original. Note that the pencil

drawing does not reproduce as well as A and B. D is printed in color from the

same plate as A.

16 SMITH

Generally the object of a scientific drawing is to get a good likeness of

the subject, using whatever method that gains this end with the

minimum effort.

Colored Drawings and Their Reproduction. In order to make a

drawing in colors, water-color paints, preferably those that come in

solid cakes, must be obtained. If one desires to mix his own colors,

a number of reds, blues, yellows, browns, black, and white are neces-

sary, for while a variety of shades can be made from red, blue, and

yellow—the primary colors—they are not always the ones desired.

A red diluted with water gives pink, whereas another entirely differ-

ent pink results from red mixed with white. It is easier to purchase

the colors wanted and to prepare a plentiful supply of wash from the

cake in the same way as the black wash is made. Where several

colors are used, they can be prevented from running into each other

by mixing the pigment in a gum-arabic solution to which a few drops

of glycerine have been added.

Inasmuch as elaborately colored drawings require reproduction

by lithography, they are to be avoided wherever possible. Some

papers on blood corpuscles contain plates in which ten separate

printings are used to obtain the fine distinction between the staining

reactions. A separate stone is necessary for each color and the artist

who transfers the work to stone must understand what colors to

superimpose in order to gain the desired effect. These separate

stones are called tint-blocks. In printing, the lightest tones are

printed first, followed by the stronger colors. An outline stone to

define the picture and one printed in gray to deepen the shadows

gives the finishing touches.

Where color gradations are not fine, a three-color process is used.

Tint-blocks made for each of the three primary colors are printed one

upon the other in such a way that various shades result. This process

is more often employed in reproducing colored-drawings by the half-

tone method. In making the negatives, photographic plates rendered

sensitive to these colors together with properly colored screens are

necessary. Ordinarily it takes twelve separate photographic opera-

tions to produce three blocks. The screen is turned at a different

angle for each plate; otherwise the dots would be directly superim-

posed in printing.

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 17

Half-tone or zinc-process plates from black and white originals

may be printed in color instead of black. Where tissues are shown

the plate may be printed in a color to resemble the stained micro-

scopic slide (Plate V, D). In case one coloris desired upon a black and

white background, a zinc-process plate is printed in color over a

half-tone in black. Prints of this kind are frequently found illustrat-

ing embryological and anatomical papers.

Lately, a few journals have obtained effective plates in one-tone

or a combination of two tones by using the heliotype process.

Photographs. Photographs are usually reproduced by half-tones

(Plate III, A). Prints on Azo hard X, glossy white Velox paper,

and solio paper of a brownish tinge, reproduce best, as the hard

finish brings out strong contrast between the blacks and whites.

Prints should be squeegeed, that is have the moisture removed from

the wet print with a roller so as to leave the gelatin film hard when

it dries. While photographs will stand some reduction, on the whole

prints should be the same size as the intended cut.

If desired, certain parts of a photographic print may be outlined

in water-proof ink, and the print then bleached with potassium iodide

or potassium ferricyanide until nothing but an outline ink-drawing

remains. This is a simple way to get an accurate outline that will

reproduce by the zinc-process method (Fig. 6).

Graphs. Graphs should be made upon coérdinate paper in which

the lines are blue. As blue does not photograph, the coérdinates,

which are to appear in the cut, both perpendicular and horizontal,

must be inked.

Reduction of Drawings. It is advisable to make drawings larger

than they will appear in the finished print as in reduction many

irregularities are lessened. But under no circumstances make a crude

drawing with the idea that the print from it will be perfect, for while

reduction minimizes, it does not obliterate defects. Ordinarily, the

original drawing should not be more than twice the size of the

intended print, while a reduction of 14 or 14 usually gives better

results. Where line-drawings are made to an enlarged scale, the

lines should not be thickened.

18 SMITH

Figure 6. A photograph in which the outline was inked and then bleached.

Reproduced by zinc-process. Contrast with plate III, A.

The Wistar Institute of Anatomy and Biology prefers that authors

make their drawings of microscopic objects or sections of such size

that when reduced the magnification will accord with one of the

numbers suggested by Professor Simon Henry Gage (See Table 1).

Table1—Standard Magnifications.

(Taken from Style Brief of Wistar Institute)

15216 5,5;,40,:15,20, 25, 30, 35; 40;'45, 50,60; 70; 75, 80; 90, 1007 125;

150, 175, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000,

1250, 1500, 2000.

Reduction always refers to linear measurement and not to area.

In reducing a drawing to 14 its original size, every line is made 4%

as long as it was drawn and the finished print occupies 14 the area of

the original. The accompanying diagram (Fig. 7) illustrates this

reduction in area.

A 5 ‘D

Figure 7. Diagram to show reduction in area. A B C D reduced 14 occupies

the space A B’ C’ D’.

Arrangement of drawings for reduction. Drawings that require a

fine screen in half-tone reproduction can not be printed as text

figures unless a superior quality of glazed paper is used. Such draw-

ILLUSTRATING BIOLOGICAL MANUSCRIPTS 19

ings are usually so arranged by the author that they may be printed

on a special coated paper in the form of plates. While line-drawings

generally appear as text-figures, they may be made into a plate, par-

ticularly where many small drawings are used. In order that a plate

may be the proper size, the amount of reduction it will undergo

must be considered when it is planned. [If all the drawings on it are

to be reduced one-third, the plate must be one-third longer and one-

third wider than the printed portion of the journal page. Drawings

may be pasted upon a bristol board in their proper sequence or they

can be drawn directly upon the board or drawing paper in such order.

The amount of reduction must also be considered in labeling.

Too large or too small letters may spoil an otherwise excellent picture.

A cut is more legible if the names printed in full are connected to the

proper part of the drawing by leaders parallel to the base-line. Since

gummed sheets containing printed letters, numerals and words such

as “‘Plate” and “Fig.” can be bought in several sizes for such work,

and even black typewritten words may be pasted on, an amateur had

better not try hand-printing other than a few letters or numerals.

Department of Zoology,

University of Wisconsin

20 SWEZY

THE OCCURRENCE OF TRYPANOPLASMA

AS AN ECTOPARASITE

By Olive Swezy

The question of the adaptation of a protozoan parasite, either

in its morphological modifications or in its physiological reactions,

to its habitat is one that presents many interesting and at the same

time puzzling aspects. In the group of so-called facultative para-

sites, largely composed of flagellates and amoebas, some forms seem

to present such adaptive modifications, particularly among the flagel-

lates. This is shown in the development of certain structures, such

as undulating membranes, and more especially of the neuromotor

system which reaches its greatest development among the parasitic

flagellates.

On the other hand, structural modifications are almost totally

lacking in the amoebas, either as obligatory or facultative parasites.

Undoubtedly physiological adaptations are present but are such as

leave no record in structural organization.

Such modifications or the apparent lack of them may be found in

both the true entozoic parasites, as well as those that are merely

commensal in the intestinal tract of the host. Thus Entamoeba histo-

lytica presents no distinct structural modifications indicative of its

dangerous parasitic career. The flagellate Bodo is apparently a

harmless commensal in the intestinal tract of frogs, etc., and differs

in no wise from the free-living representatives of the genus. The

mode of adaptive response in both cases is physiological and not

structural.

However, when this comparison is extended to protozoans infest-

ing other parts of the body a different state of affairs is found, as most

if not all, these parasites are forms which have no representatives

among free-living species. This is true of the large group of Sporozoa

and of the haemoflagellates as well, with a single exception which will

be pointed out below. This fact is probably accounted for by the

higher degree of specialization which an organism must attain before

it finds itself at home in an environment such as the blood, which

differs so greatly from the habitat from which it originally came.

TRYPANOPLASMA AS AN ECTOPARASITE 21

The degree of difference between conditions in the intestinal tract of

a frog and of the water in which it lives is not so great as that between

the intestinal tract and the highly oxygenized blood-stream.

The single exception to this among the true haemoflagellates is

found in the genus 7rypanoplasma. This genus contains a number

of species which may be divided into three groups according to their

habitat. The first of these are parasitic in the blood of fresh water

fishes, the second in the digestive tract of marine fishes and the third

in various invertebrates. Minchin (1912) doubts the validity of plac-

ing all the flagellates that have been thus described in a single genus.

Habitat alone, however, cannot be used as a generic distinction.

This small flagellate to which had earlier been given the name

Trypanoplasma carassii (Swezy, 1915), is found as an ectoparasite

on gold-fish. No evidences are forthcoming to indicate that it is

truly parasitic in its habits, but it is rather a commensal, living in the

mucus that is ordinarily present on the surface of the fish. Costia

necatrix is usually found associated with it. Examinations were fre-

quently made of the water in the aquarium containing the gold-fish

but no flagellates were found in it. To secure them the body of the

fish must be lightly scraped with a scalpel or other instrument.

The body of the flagellate is roughly triangular in shape with the

broader end anterior (pl. M, fig. 3). Its length varies from 5 to 12y

and its width at the anterior end about 3 to 7y. In many cases the

body is long and slender, more nearly approaching the trypanosome-

like form of the blood-inhabiting species (pl. VI, fig. 2).

The neuromotor system consists of a vesicular nucleus, parabasal

body, blepharoplast, with their connecting rhizoplasts, and two

flagella (pl. VI, fig. 3). The nucleus is situated near the middle region

of the body or slightly anterior, and usually at one side. It is rela-

tively large and vesicular in type, with a large central karyosome bor-

dered by a distinctly light area. In the more slender, attenuate forms

the vesicular structure is often obscured, the entire nucleus taking

a dark stain. On the opposite side of the body, at the same level or

slightly anterior to it, is the parabasal body. This is usually rounded

in shape but may be slightly elongated or even somewhat irregular

in outline. It stains a deep black with iron haematoxylin and shows

no differentiated structure. It is connected with the nucleus by a

slender, deeply staining rhizoplast.

22 SWEZY

In front of this structure and near the antero-lateral margin of

the body, is the blepharoplast. This is composed of a single granule

from which arise the two flagella (fig. 3). It is connected with the

parabasal body and apparently also with the nucleus itself by slender,

deeply staining rhizoplasts. In some cases the rhizoplast connecting

the nucleus and blepharoplast cannot be distinguished (fig. 1). In

most of the flagellates observed, however, the three rhizoplasts are

present, i.e. from the nucleus to the parabasal body and also to the

blepharoplast and from the blepharoplast to the parabasal body

(fig. 3), closely linking together these three parts of the neuromotor

system.

One of the two flagella is directed anteriorly, the other posteriorly.

The former may have a length two or even three times that of the

body. The posteriorly directed flagellum is usually much shorter,

sometimes not exceeding the body in length. It is attached to the

surface by a thin membrane which may show an undulating line

(fig. 3) or may present a nearly smooth contour (fig. 2).

A comparison of Trypanoplasma carassii with the blood inhabit-

ing species of the genus shows no important differences. In T. borreli

as figured by Keysselitz (1905) the body has the same general form,

narrower posteriorly, but, unlike 7. carassii, shows a strongly marked

curvature or sickle-shaped outline. It is also much larger than the

latter species, its length varying from 10 to 40u. The parabasal

body is elongate, extending from near the blepharoplast backward

along the lateral margin of the body with a length that may some-

times equal one-third or more of the total length of the body (fig. 4).

Intestinal species do not differ materially from the blood-inhabiting

forms. Trypanoplasma congeri, from the stomach of the conger

eel (Martin, 1910), has a slender, elongate form (fig. 5) with the same

type of parabasal body and nucleus found in T. borreli. The nucleus

shows a tendency to assume an oval shape in some individuals.

It is thus evident that this flagellate with an ectoparasitic habit,

presents no specific structural differences distinguishing it from other

species of the same genus inhabiting the blood-stream. Its occurrence

is noteworthy as being the only example of the haemoflagellates

which has thus far been described from a habitat outside the body of

a living animal. The genus probably represents a transition stage

between the strictly intestinal group of flagellates and the haemo-

TRYPANOPLASMA AS AN ECTOPARASITE 23

flagellates or blood-inhabiting forms, with this species still retaining

the ability to live outside of its normal host as do other of the ordinary

intestinal flagellates. No trypanoplasmas were found in the intestinal

tract or blood of the gold-fish from which these flagellates were taken.

This precludes the possibility of an accidental infection of these fish

from the faeces.

Trypanoplasma carassii is much smaller in size than either of the

other two species and is one of the smallest that has been described

for the genus. In the structure and arrangement of the nucleus and

parabasal body it presents some striking resemblances to Prowazekia

to which genus it could properly be assigned were it not for the pres-

ence of the undulating membrane. These resemblances suggest an

evolutionary development of this genus from Prowazekia or a similar

form.

The interrelations of the various parts of the neuromotor system

in Trypanoplasma have not been figured by previous investigators.

It is probable that the same connecting rhizoplasts are present in all

the species of this genus, linking together the blepharoplast, nucleus

and parabasal body.

The facts concerning the life cycle of Trypanoplasma are still

obscure and await further investigation. Even its methods of divi-

sion have not been thus far satisfactorily accounted for. Nor can

any light be thrown on these questions from present work on this

species from gold-fish. Division forms were not observed. Its

minute size renders it a difficult object to work with satisfactorily.

University of California

24 SWEZY

LITERATURE CITED

KEYSSELITZ, G.

1906. Generations—und Wirtswechsel von Trypanoplasma borreli Laveran

and Mesnil. Arch. Prot., 7, 1-74, 162 figs. in text.

Martin, C. H.

1910. Observations on Trypanoplasma congeri. Part 1, The division of the

active form. Quar. Journ. Micr. Sci., 55, 485-495, pl. 21, 1 fig. in text.

Mincain, A. E.

1912. An introduction to the study of the Protozoa. (London, Longmans,

Green and Co.), xi-517, 194 figs. in text.

SWEzy, O.

1915. The kinetonucleus of flagellates and the binuclear theory of Hartmann.

Univ. Calif. Pub. Zool., 16, 185-240, 58 figs. in text.

EXPLANATION OF PLATE

Fig. 1. Trypanoplasma carassii Swezy. Ordinary trophozoite showing the typica

Outline with single blepharoplast, flagella, undulating membrane, parabasal body and

and nucleus. The rhizoplast connecting the blepharoplast and nucleus could not be

detected. 2235.

Fig. 2. Slender elongate form of the same. 2235.

Fig. 3. Typical form of trophozoite with the rhizoplast connecting the nucleus

and the blepharoplast. 2235.

Fig. 4. Trypanoplasma borreli Laveran and Mesnil. After Keysselitz (1906,

fig. 13). Normal trophozoite showing the elongate parabasal body. Rhizoplast are

lacking. 2235.

Fig. 5. Trypanoplasma congeri Martin. After Martin (1910, fig. 1). Normal

active trophozoite. A line of faintly marked cytoplasmic granules follows the base of

the undulating membrane. 2235.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIIIjff

PLATE VI SWEZY

DEPARTMENT OF NOTES AND REVIEWS

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 mem-

bers are invited to submit such items. In addition to 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.]

THE NEW TREASURER

Owing to press of duties, Dr. H. J. Van Cleave, at the end of his

three year term, has felt it necessary to offer his resignation as Treas-

urer of the American Microscopical Society. In as much as no meet-

ing of the Society was held in 1918, this resignation was acted on by

the Executive Committee. In accepting Dr. Van Cleave’s resignation

the Committee in both formal and personal ways recorded their great

regret and their thanks to him for a most capable and constructive

administration of the office.

Mr. Wm. F. Henderson, Instructor in The James Millikin Univer-

sity, Decatur, Illinois, was named Treasurer for the ensuing term,

subject to ratification at the next constitutional meeting.

THE PROBLEMS OF THE FUTURE

The Secretary wishes to call the attention of the Society to the

fact of the great loss, especially among our younger members, during

the last four years. This is neither a surprising, unique, nor prostrat-

ing experience. It is common among societies of this kind. It

does, however, call for heroic and thorogoing coéperation among

the membership.

I am sure that every member of the American Microscopical

Society has confidence that science and scientific research will not

suffer permanently after the war. Whatever of our predilections and

practises have been shown to be either ineffective or false by the

events of the war, science and scientific men showed that the future

is helpless without them.

Our own Society, publishing as it does from 300 to 400 pages each

year of the results of research in fundamentally important fields of

human interest, ought to enter firmly and confidently into its portion

26 NOTES AND REVIEWS

of this future progress. The fields opened up by the microscope—

whether in zoology, botany, histology, pathology, medicine, bacter-

iology and sanitation; or in the hundreds of more specialized indus-

trial aspects of food examination, textiles, agriculture, chemistry,

mineralogy, and the like—will be greatly enlarged during the next

quarter of a century.

The Secretary feels that our Society has some very definite advan-

tages to offer to the younger generation of students who must use

the microscope. Our scope is much more catholic and general than

that of most societies, and is yet quite specific and technical enough

to serve the specialist. Our publications ought to be peculiarly

valuable to those who do not have access to large lists of special

journals.

He desires, therefore, to ask very earnestly that all members,

beside keeping alive their own membership, aid him in the following

ways :—

1) Send to the Secretary the names of any persons likely to be

attracted by our program. These may well be of your present ad-

vanced students, recent students who have gone out into teaching

or other work of a scientific kind, colleagues, acquaintances among

progressive high school or college teachers, and isolated workers

with the microscope.

2) Send in, suitably illustrated for publication, the best dis-

coveries you are making of methods of work, of technical appliances,

or of making truth clear to others. We aspire to become one of the

best channels in the country for the presentation of such technical

notes, in our Department of “Notes and Reviews.”’

In a ‘‘mutual”’ association like this, where there is no endow-

ment, there is at once the necessity and the privilege of complete and

hearty codperation. As he enters the tenth year of service to the

Society, the Secretary feels more than ever that this may be made

the most prosperous period in the whole history of the Society.

CRYSTALS IN AMEBAS

Schaeffer reports (Baltimore meeting Am. Soc. of Zoologists, 1918)

that crystals, reasonably distinctive in shape and size, characterize

different species of amebas. These crystals are within vacuoles and

AMERICAN MICROSCOPICAL SOCIETY P|

are thus not in direct contact with the endoplasm in which they

occur. The author believes them excretory, altho their composition

has not been determined. Their presence seems to be correlated with

the physiological states leading to division. Actively dividing ame-

bas have few crystals. Those that are not dividing become so loaded

up with crystals as to produce opaqueness and to impede locomotion.

It has not been possible to determine whether the crystals, once

formed, are ever resorbed again.

MONTANA TREMATODES

Faust (Ill. Biol. Monog. Vol. IV, No. I, July 1917) reports on the

larval trematodes found infesting the snails of Bitter Root Valley,

Montana. Fourteen new species are described from this biologically

isolated fauna. Two of these are monostomes, two are holostomes,

and ten are distomes. Thisis a large number of species for so limited

a territory. The percentage of infection of the snails is very high.

The author has studied only the cercariz and the parthenogenetic

stages whereby these larvae are produced, the mature worms not

being known in any of the species. The principal results of the study

are summarized as follows:

1. The history of the germ cells in sporocysts and redi# shows

that they are true parthenogenetic ova, with one polar body and no

reduction of chromosomes.

2. Consequently the parthenite (sporocysts and rediz) are not

“larval” in any real sense; but we have an alternation of partheno-

genetic generations with hermaphrodite generations.

3. The manner of forming the egg cells, the origin of the layers,

etc. give evidence that the parthenite, cercarie, and miracidia are

homologous, tho distinct, life histories.

4, The trematode integument is mesodermal in origin.

5. The fundamental systems (e.g. excretory, genital, and nervous

systems) of the adult are manifest in the cercaria and may be used to

show relationships.

6. Holostomes are probably of distome origin, and have, in com-

mon with the other families, the alternation of hermaphrodite and

parthenogenetic generations.

28 NOTES AND REVIEWS

7. The parthenitz are to be looked upon as physiologically young,

and thus able to continue the parthenogenetic cycle for several

generations without the hermaphrodite generation.

8. This youth and the attendant simplicity as compared with the

miracidium is to be looked upon as secondary results of parasitism.

THE CRYSTALLINE STYLE OF LAMELLIBRANCHS

Nelson (Jour. Morp. Vol. 31, June 1918) presents a review of the

work done on the crystalline style in Lamellibranchs, and contributes

some interesting results of his own about this singular organ.

The lining of the intestine and of the communicating style sac

is ciliated. This ciliary mechanism is regarded as having power to

separate food from the foreign particles within the tract. Little

discrimination is shown as to material taken into the stomach.

The style arises as a thin core of bubbly mucus upon which co-axial

layers of a gelatinous protein, containing enzymes, are deposited.

The style rotates in the sac, according to the observer. He confirms

the conclusion that it contains strong amylolytic ferments and

believes that the style serves as a means of restoring to the stomach

undigested food particles which might otherwise be lost, at least in

those forms in which the style sac is not separated from the intestine.

The store of ferment is thought to be of peculiar value because of

the long period during which feeding is impossible in many mollusks.

REVIVIFICATION OF EXSICCATED EARTHWORMS

Schmidt (Jour. Exp. Zool., October 1918) has shown that earth-

worms are capable of being revivified after 39 to 48 hours (depending

on temperature) of exsiccation in which they have lost one-third to

one-half their lenth and volume, and show no signs of life that can be

detected. The worms were of course very gradually dried. The

body must be allowed to retain its elasticity and the skin its softness,

if revival is to be expected. Life was normally regained after as

much as 61.6 per cent of the weight of body (nearly 73 per cent of

the weight of water in the body) had been lost.

tg: The earthworms differ from lower animals like rotifers and nema-

todes in that they cannot be preserved thru such long periods of time.

This is probably due to the fact that they are more complicated,

cannot be so completely desiccated, and hence decomposition

AMERICAN MICROSCOPICAL SOCIETY 29

changes, thru the presence of microorganisms in the gut, are more

likely.

The adaptive quality of this power to sustain loss of water without

loss of life is manifest, when we remember the fact that earthworms

must meet considerable range of variation in the moisture of the soil

crust which they inhabit.

LIFE BEHAVIOR OF ASCARIS

Ransom and Foster (Baltimore meeting of the American Society

of Zoologists, 1918) report interesting points in the life history of

Ascaris lumbricoides. It was found by them that partial develop-

ment may take place in many hosts which are not suitable for the

complete life history. Rats and mice are less favorable than lambs

and goats. The partial development in the rats and mice led Stewart

to believe that these animals were the intermediate hosts of the

Ascaris found in man and the pig.

The normal life behavior is stated as follows: Eggs after being

swallowed hatch in the intestine. Shortly after hatching the larvae

occur in the portal vein and the liver. The lungs, reached thru the

circulation, are a point of rapid development. The larvae pass back

to the intestine by way of trachea and esophagus. If the animalisa

suitable host mature development is reached here. If not, the larvae

are lost with the feces.

REVERSAL OF ORIENTATION TO LIGHT

Mast (J. Exp. Zool. Jan. 1919) records that Volvox and Pandor-

ina react similarly to light. He finds dark-adapted colonies which

are usually positive in weak illumination and negative in strong.

Light-adapted colonies are sometimes positive in strong and negative

in weak light.

If dark-adapted colonies are exposed to continuous illumination

they suffer a series of reversals of orientation, the time required for

which depends on the intensity of light. They are neutral for a short

time; then become positive, passing thru a maximum; after this they

become neutral again; then they become negative, passing thru a

maximum; again they become neutral, and then pass finally into a

positive state.

Green and blue rays are most influential both in stimulation and

in producing the reversal of orientation. This sense of orientation is

30 NOTES AND REVIEWS

modified by changes in temperature, by the constitution of the culture

medium, by the age and physiological state of the colonies.

REACTIONS OF LAND ISOPODS TO LIGHT

Abbot (Jour. Exp. Zool. Nov. 1918) finds that the land isopods,

Oniscus and Porcellio, are negatively phototactic to all intensities

from 0.01 C.M. to 100 C.M., whenever not immersed in water. He

concludes that the orientation is direct and not by selection of ran-

dom movements; and that this negative phototaxis is apparently

a factor in fitting them for life on land by aiding to keep them in a

suitably moist habitat. The negative quality is more pronounced

in Oniscus, which has the more restricted habitat.

ASSORTIVE MATING IN CHROMODORIS ZEBRA

Crozier (Jour. Exp. Zool. Nov. 1918) finds that there is high

degree of assortive mating in the large nudibranch mollusc Chromo-

doris zebra. This assortive mating expresses itself in the correlation

in the size of mates—large with large and small with small. Since

the species is hermaphrodite and a mutual exchange of sperm is nor-

mally to be effected, this selective mating on the basis of similar size

and consequently appropriate position of the reciprocal organs is

an advantageous adjustment. It is a conservation of sexual elements;

and when large individuals mate together the numbers of eggs ferti-

lized is greater than would be true in mismatings at random.

ADAPTIVE COLORATION IN CHROMODORIS ZEBRA

Crozier (Baltimore meeting of Am. Soc. of Zool. 1918) concludes

that the coloration in C. zebra has no adaptive significance either in

its origin or at present. This, in spite of the fact that the organism

has brilliant yellow pigment, that there is sufficient variation in

coloration to furnish basis for selection, that the species actually

suffers extensive injuries from animals capable of seeing the color,

and that i: possesses ‘an efficient repugnatorial apparatus” which

would conceivably make ‘‘warning”’ coloration useful. The types of

injury seem in no way correlated with either the intensity or the dis-

tribution of the pigment.

CAMOUFLAGE IN REEF FISHES

Longley (Baltimore Meeting Am. Soc. of Zoology, 1918) reports

studies on the coloration and habits of West Indian and Hawaiian

AMERICAN MICROSCOPICAL SOCIETY 31

reef fishes. He finds that their fixed colors, excepting red, repeat the

dominant color of the surroundings, and that the change of color in

moving from place to place is induced by, and on the whole in accord-

ance with, the nature of the places into which they go.

When the following varieties of color are possible to the individuals

of a given species, cross-banded markings are likely to be shown when

at rest, and longitudinal or self-colored phases when about to move

or when actually moving.

To the fact of change of color when moving horizontally, the

author adds the observation that there are similar definite phases of

color change in some fishes for vertical movement. A vertical change

of even a few inches may be followed by definite changes of color.

_The author feels that some of the changes of color usually charged

as being connected with mating are probably so to be considered

only because of place changes at the reproductive season, rather than

as directly related to reproduction.

GLYCOGEN IN THE NERVOUS SYSTEM

Gage (J. Comp. Neur. June 1917) uses the methods of microchemi-

cal analysis to determine the presence and quantity of glycogen in

the nervous system of Vertebrates. He finds abundant glycogen in

the cells of the nervous system, at some stage of development, in all

groups of vertebrates from amphioxus to mammals. Amphioxus, the

lamprey, Amblystoma, the chick, and the pig were carefully studied.

Glycugen is also found plentifully in sensory epithelia and in related

organs.

The author feels from his results that glycogen is an essential

accompanier of the development of nervous (and all other) tissues,

especially in their functional stages;—being produced and used by

the protoplasm as an essential feature of its metabolism. After the

tissues, nervous and other, reach their final form this glycogenic

function, as we know it in the higher forms, may be given up largely

by the various tissues, and be taken over by the liver and the muscles.

EFFECT OF STRAIN ON DEVELOPMENT OF BONE

Howell (Anat. Rec. Vol. 13, Oct. 1917) produces paralysis of the

muscles working the bones of the arm and shoulder by cutting the

main nerves of the brachial plexus in young puppies. This removed

32 NOTES AND REVIEWS

the stresses usually experienced by these bones. The results show

definitely that the strains put upon the bones by the muscles are

not necessary to the growth of the bones. Such unstressed bones

grew as much as 56% to nearly 100% in four and one-half months.

On the other hand bones unstressed by muscles were much smaller

in diameter, in the thickness of compacta, in the sizeof the trabec-

ulae; were reduced in weight and in their resistance to crushing.

Growth in length seems little influenced.

EPITHELIAL MOVEMENTS IN VITRO

Shinichi Matsumoto (Jour. Exp. Zool. Vol. 26, Aug. 1918) reports

experiments in the culture of corneal epithelium of adult frogs in

vitro. This is a favorable material because the transparency of the

cornea is such as to allow direct observation of the cell movements.

Various substrata were used—as flat surfaces of glass, celloidin, and

dead cornea; spider web, silk fiber, glass wool, asbestos fiber; and

porous bodies, such as thin pieces of pith.

The movements are amoeboid, with the cells tending to cling to

their own kind and thus to form sheets. This is a most essential

quality in forming and extending epithelial surfaces. The author

believes this to be thigmotactic rather than chemotactic in nature,

extending as they do over various types of surfaces. Rapid extension

of epithelium may thus take place with no mitotic divisions at all.

The same author (Jour. Exp. Zool. Oct. 1918) discusses the technic

and results of vital staining of these corneal cells in neutral red.

When this was done by immersing the whole animal in a weak solu-

tion (1:100,000 to 1,000,000) the excised cells behaved in vitro just

about as the unstained cells do, and were more readily followed be-

cause of the distinctness of the granules in the cytoplasm.

The corneal epithelium, incidentally, showed clear phagocytosis

of the pigment of broken iris cells and of finely powdered granules

of various stains.

ENTOMOLOGICAL ABSTRACTS

Physiology of Chironomus Larva.—In a study of the biology and

physiology of the larva of Chironomus gregarius, Pause (1918, Zool.

Jahrb., Abt.f. all. Zool. u. Physiol., 36:339-452) finds, among other

things, that this larva has four molts. Tracheae, absent in the first

instar, appear in the second, and are confined to the head and thorax.

AMERICAN MICROSCOPICAL SOCIETY 33

They play no part in the process of respiration and are to be regarded

as rudimentary organs. Exchange of gases is accomplished through

the circulatory system A membrane, in the 11th and 12th segments,

is so located that the blood stream is directed into the blood gills

before it can return to the heart, thus making the latter strictly an

‘‘arterielles Herz.”’ The haemoglobin which occurs in diffused form

in the blood first appears in the second instar, its formation being

coincident with the reversal of the distinct positive phototropic

reaction of the young larva into a strong negative phototropic reac-

tion. There is evidence that the amount and time of formation of

the haemoglobin are not influenced by differences in nutrition or

light reduction. The circulatory system supplies the tissues with

oxygen, carries away the carbonic acid, and serves as a means of

storing oxygen which can be utilized when the dissolved oxygen in

the surrounding water becomes reduced. The larva of Chironomus

gregarius requires some oxygen, but shows considerable resistance

to oxygen reduction, this resistance increasing with the formation

of haemoglobin. It succumbs to an oxygen content of 0.10 cc. per

liter and it appears that 0.2 cc. per liter is very near the minimum

quantity.

Wing Development in A phids.—Shinji (1918, Biol. Bull., 35:95-

116) reports that for a number of the common aphids certain chemi-

cals in the soil in which food plants are grown—salts of the alkalis

(Na, Cl K, etc.) and alkaline earths (Ca, Br,) constitute ‘“‘non-wing-

developing substances” while others (salts of the heavy metals, of

magnesium, sugar, etc.) are “wing-developing substances.” The

former were only effective when applied within a certain period after

birth, the period varying with the temperature and the species (in

early summer—2-3 days in Macrosiphum rosae; 5-7 days in Macrost-

phum solanifoliae and A phis brassicae). A M/100 solution of mag-

nesium sulphate operating for 12-24 hours produced nearly 100%

winged individuals in Macrosiphum rosae. Aphids reared on twigs

charged with non-wing-developing substances and subjected to sud-

den temperature changes of 100° F. to 35° F. failed to produce

winged forms.

Sex Determination in Hymenoptera.—Whiting (1918, Biol. Bull.,

34:250-256) finds that in Hadrobracon brevicornis, a parasitic wasp

which deposits its eggs upon caterpillars of the Mediterranean flour

34 NOTES AND REVIEWS °

moth, both bisexual and parthenogenetic reproduction occurs.

Fertilized eggs produce females and unfertilized eggs produce males.

Comparison with the honey bee leads to the supposition that

the males are haplonts and the females diplonts.

Locomotion of Caterpillars.—Turner (1918, Biol. Bull., 34:137-

148), in a series of experimental studies on surface feeding caterpil-

lars, finds no evidence that their locomotions are tropisms. Such

movements are “‘identical with those made by animals that learn by

the trial and error method.” Physiological unrest due to unusual

environmental influences induce random movements which continue

until stopped by fatigue or by attainment of more favorable environ-

mental conditions.

Zoraptera.—Caudell (1918, Can. Ent., 50:375-381) describes a

new species of Zoraptera (Zorotypus hubbardi) from ten specimens

taken from termite galleries in Florida. The order Zoraptera was

established by Silvestri in 1913 for three species of a single genus

(Zorotypus): guineensis from Africa, ceylonicus from Ceylon, and

javanicus from Java. He also described (1916) a new species (Z.

neotropicus) from Costa Rica. The presence of this very primitive

insect on the continent of North America is thus made known for

the first time.

Immunity Principles in Insects —Glaser (1918, Psyche, 25:39-

46) finds that the value of the insect blood cells in ridding the body

of foreign substances has been greatly exaggerated and that in reality

they are usually rather passive. In grasshoppers and caterpillars,

the blood cells do not seem to ‘“‘phagocytose bacteria in an amaeboid

fashion”? and when bacteria occur in blood cells they may have

entered of their own accord or have been included through some

physical factor. However, blood seems able to overcome bacterial

invasion to some extent due to elaborated substances which consti-

tute extracellular antagonistic substances. Immunized grasshopper

blood exhibits a marked degree of antagonism towards the bacteria

used in producing immunity. The existence of an agglutinin in

immune grasshopper blood was demonstrated.

Polyembryony in Insects.—Gatenby (1918, Quart. Journ. Micr.

Sci., 63:175-196) presents a review of polyembryony as it occurs

in the parasitic Hymenoptera, giving particular attention to the

work of Marchal, Silvestri, Martin, and Patterson. Polyembryony—

AMERICAN MICROSCOPICAL SOCIETY 35

the production of numerous embryos by a single egg—in insects is

known at present in only two families of the parasitic Hymenoptera

(Chalcididae and Proctotrypidae). Eggs of these parasites, ferti-

lized or unfertilized, are deposited in the eggs of various insect hosts

and develop in the subsequent larval stages of the latter. Polar

bodies, given off by the parasite’s egg, develop into a growing mass

of nuclei, and the polar cytoplasm forms an investing sheath about

the embryonic ooplasm, the latter ultimately producing the embryos.

By repeated division, the primary embryonic cell gives rise to many

germinal masses (polygerms) which continue to divide, ultimately

resulting in numerous masses each containing an embryonic mass

surrounded by two membranes. These final masses produce indivi-

dual embryos, which later, as larvae, break away from their mem-

branes and are free-living in the haemocoel of the host for a time,

consuming the body tissues of the latter. Resulting broods may be

exclusively male, exclusively female, or mixed, the latter probably

resulting from two or more eggs, fertilized or unfertilized. As known

at present, fertilized eggs produce females and unfertilized eggs,

males. Gatenby claims that the “germ-cell determinant”’ is possibly

a “‘nutrient cytoplasmic-mass”’ and does not later form the germ

cells of each embryo; that there is no evidence of a germ-track and

that ‘‘mere position in the morula is all that seems to determine

whether this or that cell will be endoderm or ectoderm cell, etc.”

He also predicts the discovery of species which are polyembryonic

or monoembryonic according to the season of the year, or according

to some condition of the host egg or caterpillar.

Light and Muscle Tonus of Insects.—Garrey (1918, Journ. General

Physiology, 1:101-125) has investigated the relationship between

the tonus or tension of the skeletal muscles and the illumination

of the eyes of heliotropic insects. Experiments were conducted

mainly on the robber flies Proctacanthus, Promachus, and Deromyita.

A number of butterflies (Circionis alope, Vanessa huntera, Argynnis

aphrodite, et al), dragon flies, certain Vespidae, and representatives

of several genera of Diptera were also used. The desired difference in

illumination was obtained by coating the eyes wholly or in part with

asphalt black varnish. When both eyes were blackened, inactivity,

muscular weakness, and incodrdination resulted. One eye blackened

led, in most of the animals tried, to circus movements towards the

36 NOTES AND REVIEWS

side of the uncovered eye. Difference in illumination produced an

asymmetry when the insect was at rest, and if it moved, it was forced

toward the side of greater illumination. Tonus changes in the muscles

were approximately proportional to the area of the eye blackened.

Blackening the lower halves of the eyes caused the anterior end of

body to be lifted far up from the horizontal support, head tilted

back against thorax, and caudal end of abdomen pressed against the

support. The exact opposite occurred on blackening the upper

halves of the eyes. Blackening the upper half of one eye and the lower

half of the other produced a combination of the effects just described.

Symmetrical blackening of outer or inner halves of the eyes resulted

in weakening of some groups of muscles but no asymmetry was pro-

duced. Insects which normally walk directly up a vertical surface

or rest with the body axis in a vertical line, veered off at an angle

towards the unblackened eye.

All heliotropic insects with one eye blackened ascended vertical

cylinders obliquely. It thus appears that the muscle tonus of helio-

tropic insects is due chiefly to light. Each eye controls the tonus

of a different group of muscles on both sides of the body and unequal

photo-chemical reactions in the two eyes lead to asymmetrical

conditions of muscle tension. The reactions vary directly with the

intensity of the illumination. These experiments yield results which

are in accord with Loeb’s muscle tension theory of heliotropism.

Gynandry in Arachnida.—Hull (1918, Journ. Genetics, 7:171-181)

divides arachnid gynandromorphs into three types: ‘1. One side

male, the other female—sexual structures perfect except for a dis-

tortion resulting from the union of dissimilar halves on the median

line.” “2. As 1, but one side imperfectly developed before, the

other behind,” and “3. One side perfectly female before and male

behind, the other perfectly male in front and female behind.” So

far as known at present gynandromorphs in Arachnida are confined

to one order, Araneae.

Somatic Chromosomes in Coleoptera.—Hoy (1918, Biol. Bull.,

35:166-169) finds that developing eggs and embryos of Epilachna

borealis show eighteen chromosomes and have two kinds of chromatin

content in somatic cells, an XY combination and an XX combination.

Embryos of Diabrotica vittata contain two chromosome groups, one

AMERICAN MICROSCOPICAL SOCIETY SF

with twenty-one and the other with twenty-two, each type being

constant in number and form in the various tissue cells studied.

Stoneflies and Plants.—Newcomer (1918, Journ. Agr. Research,

13:37-41), has studied the life history and habits of certain western

stoneflies belonging to the genus Taeniopteryx. While adult Plecop-

tera are usually referred to as possessing the biting type of mouth-

parts, several American species have mouthparts which are more or

less rudimentary. However, four species were found to possess well

developed biting mouthparts and feed actively upon certain plants.

Taeniopteryx pacifica was found to have the mandibles, maxillae,

and labium completely developed and functional. While the foliage

and buds of apricots, peaches, and plums are eaten, it is probable

that such food habits are acquired. Of the native vegetation along

streams, the foliage of the wild rose, wild cherry, alder, and elm and

the leaves and catkins of willows are used as food. Two other species

(Taeniopteryx nigripennis and T. pallida) feed actively upon thimble-

berry, alder, willows, wildrose, serviceberry, and maple. Another

species (Taeniopteryx, sp.) was observed feeding upon young cherry

leaves.

Gynandromor phism.—Pettey (1918, South African Journ. Sci.

14:425-426) describes a case of right-left gynandromorphism in the

moth Metanastria pithyocampa Cram. Sexual dimorphism in this

species is exhibited by such characters as coloration, antennae, size,

and pubescence, thus making a gynandromorph rather easily dis-

tinguishable. A male was found in connection with the gynandro-

morphic individual and in the copulatory position.

Oviposition of Notonectidae—Hungerford (1918, Ent. News,

29:241-245), in a study of the oviposition habits of certain Notonec-

tidae (N. undulata; N. variabilis; N. insulata; N. irrorata), finds that

the first three mentioned have ovipositors poorly adapted for making

incisions in plants of sufficient size to receive eggs and that while

they are capable of abrading the surface of stems, only JN. tirrorata

possesses an ovipositor capable of inserting the eggs in plant tissues.

N. irrorata was observed to deposit eggs in the stems of moneywort,

Juncus, and dead Typha, while the other species attach their eggs

to the surface of stems. It is suggested that the structure of the

ovipositors should be taken into account in determining the relation-

ship of various species of Notonectidae.

38 NOTES AND REVIEWS

Development of Flesh flies —Kunkel (1918, Journ. Exp. Zool.,

26:255-264) has tested the effects of mammalian thymus and thyroid

on the development of flesh flies (Lucilia caesar and Lucilia sericata).

When fed exclusively upon thyroid, growth of the larvae is slightly

retarded; the resulting pupae are reduced in size, pupation is initiated

earlier than normal and the period of pupation is shortened. Thymus

tends to increase the size of the larvae. The results resemble those

of similar experiments with vertebrates but are not so striking.

Terminology of Metamorphosis—Comstock (1918, Ann. Ent.

Soc. Am., 11:222-224) points out that in insects usually designated

as having incomplete metamorphosis two distinct types of metamor-

phosis occur, one represented by such orders as Hemiptera and

Orthoptera in which the development is direct, and the other repre-

sented by Plecoptera, Odonata, and Ephemerida in which there is

cenogenetic development. The recognition of the distinct differences

existing between the two groups of insects heretofore associated

together gives support to a proposed revision of the following form:

(1) Gradual Metamorphosis or paurometabolous development, char-

acteristic of Orthoptera, Hemiptera, et al. (2) Incomplete Metamor-

phosis or hemimetabolous development, characteristic of Plecoptera,

Odonata, and Ephemerida. (3) Complete Metamorphosis or homo-

metabolous development, characteristic of Diptera, Lepidoptera, et

al. Comstock proposes the restriction of the term nymph to the

immature stages of gradual metamorphosis; the term naiad for the

immature stages of Plecoptera, Odonata, and Ephemerida; and

the term /arva for the immature stages of all insects having com-

plete metamorphosis.

PAUL S. WELCH.

Depariment of Zoology,

University of Michigan.

NOTES ON TECHNIQUE

(Abstracted by Dr. V. A. Latham)

A Mounting Medium.—The best mounting medium is liquid

petrolatum. It has the proper consistency for mounts, is less sticky,

does not become acid as is so common with the usual Canada balsam

AMERICAN MICROSCOPICAL SOCIETY 39

of these times, does not require thinning with its solvent which os

changes the refractive index and causes blood stains, such as that of

Romanowsky, to fade. It has superior optical qualities. It is easily

used for small insects and for sporangia of fungi, especially moulds.

For permanent mounts the cover must be sealed with gold size or

other cement. For the introduction of this liquid medium I believe

we are indebted to Dr. Alfred C. Coles of England, who gave the

method of using. (“Paraffin as an Oil Immersion Fluid,” in English

Mechanic, February 14, 1914). His work on Spirocheta pallida

in the same journal for Dec. 1909, p. 267-8 and on the flagelle of

Bacteria, idem. Dec. 1909, page 308, will interest many.

Further Note on Mounting in Liquid Petroleum “Sea-cure” (English

Mechanic, Jan. 17, 1919) suggests the following: Make the smear of

bacteria or prepared Diatoms on thin glass. After drying, fix in

1/20 solution of carbolic acid before staining, if bacteria. Then

stain, put on one drop of liquid petroleum, and use a cover glass

and cedar oil for immersion. When the examination is finished wash

off the petroleum by slipping the slide into a stoppered bottle of

petrol. Keep the slide in a vertical-rack slide box. Number the

slide and keep your notes in the box with it. This method is much

easier for use with malarial slides in the tropics, and with preparations

where the aniline stains have been used as these are not affected by

petroleum in the way they are by the cedar oil. If microscopists

would study Bacteria as they do Diatoms with dark ground illumina-

tion and a 1/12 oil immersion and with oblique light, some new

results might be achieved for science.

Simplified Technic for Determination of Pale S pirochetae.—Quioc.

(Paris Medical, p. 73, July 27, 1918,8,No.30; Abstract, J.A.M.A.

p. 1616, Nov. 9, 1918) describes the superior and unfailing advan-

tages of the Fontana-Tribondeau technic in the early or late differen-

tial diagnosis of syphilis. The organis debris and red cells are

partially dissolved, while the pale spirochete is shown up clearly from

other spirochetes. (T) Dissolve cold 1 gm. AgNOscrystals in 20 cc.

of distilled water. Reserve part of this solution, and add to the rest

ammonia, a little at a time, stirring constantly, until a sepia precipi-

tate is thrown down, and then disappears anew. Now add the

reserved solution, fractioned, until there is a slight turbidity, persist-

ing during agitation. This reagent sheltered from light, keeps well.

40 NOTES AND REVIEWS

Dry the specimen carefully, and cover it for 30 seconds, 2 or 3 times,

according to its thickness, with Rugés solution (1 cc. of crystallized

acetic acid in 100 cc. of a 2% solution of formaldehyd). This dis-

solves the haemoglobin. Rinse in alcohol; then pass thru flame to

burn off all traces of the alcohol. Cover specimen with a solution of

tannin (5 gm. of tannin and 1 gm. of glacial phenol in 100 gm. water).

Heat till it steams. Let it steam 1 minute, then rinse till all trace

of tannin solution is gone. Dry. Cover with the nitrate solution.

Rinse and dry. All the spirochetes take an even deposit of the silver,

and look uniformly thicker and extremely distinct. The pale spiro-

chete retains all its special characteristics, showing up dark purple

against a transparent background or against the light yellow back-

ground of the decolored red cells.

Enlarged photographs in Forensic Medicine.—Martin of Lyons

University, France, says the most valuable information is derived

from enlarging a photograph of a fire-arm wound in criminal cases.

The stereoscopic view, enlarged several diameters brings out details

which otherwise entirely escape notice.

Improved Staining Technic. P. del Rio-Hortega (Revista Espaii-

ola de Medicina y Cirugia, Barcelona. Sept. 1918, L. No. 3: and

J.A.M.A., p. 1620, Nov. 9, ’18) gives details of a method for histo-

logic specimens with an ammoniacal solution of silver carbonate,

prepared with lithium carbonate from silver nitrate. Histological

details are said to be shown up much clearer than with the classic

technics. Especially useful in amylosis and for nerve fibers and

tumors.

The Amoebas infesting man. H. Aragao (Annaes Paulistas de

Medicina Cirugia, S. Paulo, page 25, February 1918, 9, No. 2;

and J.A.M.A., 29 December 14, 1918) mentions the increase, in

cases reported for S. Pau'o within the last 6 years, from 4 to 543.

Drugs do not act directly on the encysted forms, but they check the

multiplication of the parasite into the encysted states. None of the

drugs that act on the E. histolytica seem to have the slightest action

on the E. coli. Differentiation is difficult if they are dead, especially

when any epithelial cells and dead leucocytes are present. He there-

fore incubtes at 37° C., for from 1% to 1 hour to restore if possible,

their mobility if lost. To stain, the faeces are diluted—0.5 cc. in 2 or

3 cc. of a 0.1% solution of gentian violet in physiological solution to

AMERICAN MICROSCOPICAL SOCIETY 41

which has been added 0.3% of acetic acid. This keeps the elements

for several days.

A Flagellate parasite occuring in a species of Euphorbia is mentioned

by J. Iturbe (Gaceta Medica de Caracas. Venezuela. August 31,

1918, 25, No. 16, page 173).

Spirochetosis, filariasis, bilharziasis, pellagra, lepra occur in Porto

Rico. See page 247, 14, No. 120 Boletin de Ja Assoc. Medica de

Puerto Rico, S. Juan, September 1918.

Preparing and Mounting Slides of Crystals. Maurice E. Parker

(English Mechanic, Jan. 10, 1919) discusses methods for making per-

manent mounts of crystals. These mounts are suitable for low

powers. Takea test tube 14 in. bore and 2 in. long, pour in a teaspoon-

ful of distilled water, then add enough of the chemical to be used to

make a saturated solution, i.e. so that just a small amount remains

undissolved. Now take a thoroughly clean slide, place a drop of the

solution on the center of it, spread the drop so it covers about 3 in.

diameter, allow to dry, taking great care no dust settles on it, as dust

shines up brilliantly in polarized light. To obtain large and well

formed crystals dry slowly; to obtain very fine, feathery crystals

dry by gentle heat. When thoroughly dry mount in Canada balsam,

being very careful not to displace the delicate crystals when pressing

down the cover. (This usually draws down to place if only just

enough medium is used.) Remember Canada balsam dissolves

some chemicals; therefore mount the same object in castor oil and

label the mountant on all slides. This should always be done, other-

wise in remounting valuable slides in Colleges and Societies, no one

can tell what treatment they should receive. Excess of the mounting

material must be well cleaned off in order to ring the slides, if castor

oilis used. Shellac is preferred for this by the technician, but Canada

balsam is a useful one as it mixes in well.

Some workers advise the use of alcoholic or ethereal solutions,

instead of aqueous, so that smaller crystals are formed, thus allow-

ing higher powers to be used. Some of the best chemicals to try

out are found among the materials used in the photographic room—

hydroquinone, potassium bichromate, pyrogallic acid, sodium car-

bonate, sulphite of sodium, sodium borate, salol, picric acid, potas-

slum cyanide (the last needs care as it is dangerous under certain

conditions). Others are menthol, potassium chlorate from the head

42 NOTES AND REVIEWS

of a safety match, kinnate quinia, salicin, sugar,etc. Try sodium

benzene sulphonate, hippuric acid, and anthracene with polarized

light. Hippuric acid can be made to vary its crystal forms. If

dissolved in alcohol and warmed, on drying they resemble the leaves

of flowers. If breathed on during cooling they take the form of

rosettes. Ortho-nitro-phenol is a complex compound of the “Ring”

series and if very thin on a slide its color effects are very beautiful.

Coumarin shows another type.

MEASURING CARBON DIOXIDE PRODUCED BY PROTOZOA

Lund (Baltimore Meeting Am. Soc. Zool. 1918) has devised a

simple procedure to determine the production of CO? by small

organisms. A wide mouth glass-stoppered bottle is used, from the

stopper of which is suspended a small flat stender dish containing

the organisms. A small quantity of weak Ba(OH): is placed on the

bottom of the bottle. This absorbes the CO, which gets into the

bottle. By proper controls the amount due to the animals can be

determined.

It was found by using small quantities of some substance, as

NazCO3, which would set free known quantities of CO2, that only

about 5% of error existed in measuring the quantity of CO: set free

by an acid from even one milligram of NapCO3. Similar accuracy

is insured for the production of the organisms.

METHOD FOR DEMONSTRATING GLYCOGEN IN TISSUES

Gage (J. Comp. Neur. June, 1917) summarizes the methods used

by him in his studies of the distribution of glycogen in Vertebrates.

1. Fix in alcohol (67-100%). A medium is necessary which does

not dissolve the very changeable glycogen. While other agents may

be used, none is so generally satisfactory.

2. Imbed either in paraffin or collodion, or the combined method

may be used.

3. For staining iodin is the only reliable and satisfactory agent.

An alcoholic iodin stain was found most satisfactory (95% alcohol,

150 cc.; water, 150 cc.; 10% alcoholic solution of iodine, 15 cc.; iodid

AMERICAN MICROSCOPICAL SOCIETY 43

of potassium, 3 grams; sodium chloride, 1.5 grams). Spread the

sections with the iodine stain instead of water. The glycogen stains

a mahogany red, which is permanent in the paraffin.

4. If permanent mounts for high power work are needed, the

sections may be immersed in the iodine stain for a few minutes,

dried thoroughly and then deparaffined by xylene. They may be

mounted in melted yellow vaseline.

SPENCER-TOLLES MEMORIAL

NUMBER

CHARLES A. SPENCER

ROBERT B. TOLLES

HERBERT R. SPENCER

Pioneer Artists in Optics and in the Development of

the Microscope in America

The publication of this number is aided by a grant from the income of the

Spencer-Tolles Fund.

TABLE OF CONTENTS

For VotuME XXXVIII, Number 2, April 1919

CAMALLANUS AMERICANUS, Nov. SPEC. with Plates VII to XVI, by T. B. Magath.

ee POC UC ELON Soe eee ete ee ce ate eek ey sO oSL, Mra ey ELE Tu ty La LORI ih CER 49

General description of Cameallanus GMeriCOnusS......1...c.ccecesccncerenececssesssessensessacsssencessases 51

SHS EGUAR MATIC GOTE Ve tavon cies. Mime areas Te AAR Uae ane DMR A eC aceite i OL aay A 54

(COLT TT Ee es ea ee Oa eee a aT RE aE IST 54

Subeuticula and longitudinal lines: 22.2... ct ccccccs suo sees seccs sasezeuohovec sel eshactiosevaskcs 60

MN EXEXCELONY: SV SUCIMG cst oe ccer cassie oyna nase ne eae ee tta as ee ete ede 65

pie eXSomatie MUSCULALUTE! cer eet neces lees eae eaeae til eae sass naere brent este eae 71

BBRE CHA MBINIUSC IES i eae ark eee ea eR hte Bec aay aut ncaghtag A culs MeN Me Aueton oes sks 78

pedi gestive: trachea neers cece ere a a ee So RLU ie cea 81

TBO KY CERI RN suns entree Racer pe el Aa A Para Aa VLC rE SLE Hae OR Co eae 106

Reproductive Organs scvr.c. tesco teeter cee ees cast el) ere eeW ek ed Sees 108

INETVOUS! Sy SECIS ices soot essen eel Me TA UU ae eee Ps Gea OL EL A NR Ean, 120

pWoumn cetera esse ta eres e see See ean re Sa Se ere ed na Vn 131

whegenus Camallanus: Railliet and Henry’ 1905.0 nc... ussite. assed ns eassatecoenteeee= 137

INfemia EOC ein EASUTETMeMES les recssce ee eee TE OLD ae ee 142

sRhe classification \of parasitic nematodesy uy ial a ei srececescas eceseesos cooee ecto eee ta 149

SUMMA: ANG! CONCLUSIONS: sre .hs haces yee re cee eee eee ERE gee cee RO eta 156

T3410) Uoyia go ay fae pepe RS en Sree ee ee een ea te pepe i Ee aE rye a ae ia 159

ea EA LION: OF HEUTES)...25. csc0 sles hee beeen eee eee ee A Mee nA es ee eae 164

WISERO MPA DLE VILA LIONS yest: c5c00 hos Se ete cties cee ere OE a LL EEE EE 169

TRANSACTIONS

American Microscopical Society

(Published in Quarterly Instalments)

Vol. XXXVIII APRIL, 1919 No. 2

CAMALLANUS AMERICANUS, nov. spec.,*

A MONOGRAPH ON A NEMATODE SPECIES.

By Thomas Byrd Magath

I. INTRODUCTION

It is as lamentable as interesting that a group of animals present-

ing so many unusual and important objects of investigation as do the

nematodes, should have received so little attention from a general

morphological point of view, despite the fact that they have been

studied from so many other angles. It is for this reason that

systematic studies upon the Nematoda have been so unsatisfactory

in the past. With the hope that a very detailed study of the

morphology of this group will throw some light on the present

chaotic situation, the author has undertaken the study of a single

species to find out its precise structure. This work has been done with

the hope that it will not only contribute definite information on certain

features of anatomy heretofore altogether unknown or at best little

described, but will furnish a stimulus to others for investigation along

morphological lines in the Nematoda. Ifas many formsareaccurately

described among this group as have been in other parasitic classes,

there can be no doubt that this difficult branch will be as easily

handled systematically as any other.

This work has been done under the direction and with the criticism

of Professor Henry Baldwin Ward. To him I express my earnest

*Contributions from the Zoological Laboratory of the University of Illinois

under the direction of Henry B. Ward, No. 129.

Publication of this monograph is aided by a grant from the Spencer-Tolles Fund.

50 T. B. MAGATH

thanks and appreciation. I further wish to thank Dr. Howard B.

Lewis and Dr. D. Wright Wilson for suggestions concerning the work

on the chemistry of the cuticula, but they assume no responsibility

for the results. For. material the author is indebted to Dr. Morris

M. Wells, the United States Bureau of Fisheries and certain members

of the Laboratory of Parasitology at the University of Illinois.

The material used for this study was a parasitic nematode, found

usually in the upper two inches of the intestine of certain turtles.

This species cannot be identified from any description previously

given and is named Camallanus americanus, n. sp.

In the table given below it will be seen that this parasite is found

in five species belonging to three genera of turtles from different

localities as indicated. In addition to these, the same species has

been identified from the following hosts in the collection of Professor

Ward: Chrysemys trossti, Chrysemys elegans and Aromochelys odora-

tus from unknown American localities. Seven individuals of Trionyx

spinifer and two of Trionyx muticus examined at Fairport failed to

reveal these forms. From these and a few other records it is evident

that this parasite occurs from Texas to South Carolina, northward to

the great lakes and along the Mississippi river. It seems likely that

the parasite is found fairly generally east of the Mississippi river.

No information is at hand as regards its distribution west of that

stream.

I. TABLE SHOWING EXTENT OF INFECTION

Host species No. No. No. un- | Per Cent Locality

examined| infected | infected | infected

Chelydra serpentina.. E 3 1 15 Fairport, Ia.

Urbana, Il.

Raleigh, N. C.

Chrysemys marginata 17 11 6 64 Fairport, Ia.

Chicago, Ill.

Chrysemys picta........ 6 5 1 83 Raleigh, N. C.

Chrysemys scripta...... 8 7 i 87 Raleigh, N. C.

Malacoclemmys

VOSUCUTE..sc05...2scca.. 12 11 1 91 Fairport, Ia.

CAMALLANUS AMERICANUS NOV. SPEC. 51

Thus, in the forty-seven turtles examined the percentage of

infection averages seventy-eight. In Table I, among the five host

species examined, the percentage of infection is lowest in the western

painted terrapin. It is interesting to note that in the soft-shelled

turtles caught in the same net with the hard-shelled species which

were infected, none of these worms were found.

The number of parasites of this species per host ranges from one

to several hundred, altho most infected turtles yield about fifteen to

twenty. These are found in the intestine just below the stomach

with occasionally one or two in the pyloric end of the stomach, or more

rarely in the lower region of the gut.

The methods of technique used have been thoroughly discussed in

an earlier paper (Magath 1916) and little has been added.

II. GENERAL DESCRIPTION OF PARASITE

These worms are of medium size, rather slender and, when first

collected, slightly reddish-brown in color. Perhaps the most notice-

able feature is the presence of the golden-brown mouth apparatus,

readily seen with the naked eye, and characteristic of the genus.

The worms are as a rule moderately active, coiling themselves up into

loose knots, but never rolling themselves up spirally, as is the custom

of some nematodes, in particular those which are characterized by

possessing soft lips.

If a bit of the intestine is placed in a dish with the worms, those

coming in contact with it sometimes seize it, and indeed they may be

seen to grasp each other in various parts of the body. There is in

the anterior region a short clear space, which is occupied by the

esophagus, and back of this region is seen the gut, usually dark in

outline or even black in some cases, as it appears thru the trans-

parent cuticula. The latter shows fine striations under magni-

fication, and the two sets of three prongs of the oral apparatus can be

made out, embedded in the cuticula at theanteriorend. Twominute

papillae are at the level of the thickest portion of the anterior region

of the esophagus; the excretory canal opens about 20 yw anteriad of

these papillae.

The posterior region of the males (Fig. 6) is inturned so as to look

like the letter “‘J,”’ the bottom of which presents two medium sized,

narrow alae, which are lateral in position; sometimes the longer

spiculum is protruded thru the ano-genital aperture.

52 T. B. MAGATH

Nearly all authors have noted the presence of caudal alae on the

males within this genus, but the description of the structure is very

incomplete. At the anterior margin of the alae, just behind a slight

indentation in the body wall on the ventral side, one sees in sections,

that the cuticula is split, so that the alae are covered with the outer

layer, the body with the inner and a space intervenes. Thealaeat

first arise as a single ventral swelling from the cuticula, but on passing

posteriorly they divide and separate more and more from each other,

until they come to lie one on either side of the mid-ventral line, and

with their ventral margins removed quite a distance from each other.

These right and left ala extend to the tip of the tail, remaining about

the same size until within a short distance from their terminations,

they taper sharply to the tip.

The alae are not very high nor broad (Fig. 87), projecting along

their course about 20 yu ventrally and 30 yu laterally beyond the body

wall. The outer contour is fairly regular, but here and there is

indented or swollen. If the body of the worm be divided in frontal

section along the mid-lateral line, it will cut at the level of the dorsal

margin of the alae, their ventral margins run parallel to each other,

but some distance apart.

Between the two layers of split cuticula there is sometimes present

a deeply staining fibrous or granular substance, varying in amount

in different individuals. I am unable to state what this substance is,

but two possibilities present themselves. The first being that as the

cuticula is laid down by the subcuticula underneath this rezion, it is

sloughed off of the lower layer into the alar cavity; the fact that the

mass increases with the age of the worms somewhat bears this out.

A second theory, suggested to me by Professor Ward, is that this

material represents precipitated fluid expressed from the body cavity.

The alae are not without support. Anterior to the anus there are

seven pairs of ribs, which are slender and extend at definite intervals

between the two split layers of cuticula. Since these supports are

discussed elsewhere in the paper, only a few points need be mentioned

here. The number and arrangement is like that in C. seurati. A rib

is like a little slender rod, and anterior to the anus the seven pairs

are about equally spaced from each other. In addition to these there

are two pairs which are para-anals, very near the anus and on either

side; finally there are five pairs situated posteriorly, the anterior

CAMALLANUS AMERICANUS NOV. SPEC. 53

three of either side being grouped together and the last two (Fig. 77).

Superficially these last five pairs seem to be pedunculated, with a

slight distal enlargement. All of these ribs, unless the postanals are

exceptions, are capable of being bent and returning to their original

position. They are covered with an exceedingly thin layer of cuticula

which is continuous with that of the body wall on the one hand and

of the alar wall on the other.

It is interesting to note in passing that. Leidy (1851) refers to these

structures as ‘‘respiratory canals’’; he found only six pairs anterior

to the anus and did not mention the presence of others posteriorly;

whether they were present in C. trispinosus is a question. At present

one is unable to say whether the number of papillae, ribs or rays is

constant for a genus or not; the reports of the number in the different

species of the genus Camallanus cannot be looked upon as being

reliable.

The females are usually larger than the males, but of about the

same ratio so far as the length and thickness of the body are con-

cerned. They are easily recognized from the males by the presence

of the large projecting vulva, situated about the middle of the body.

The tail is drawn out into a long conical point, without alae, and under

a medium magnification shows the presence of three minute spines

(Figs. 8,113). Under the same magnification the uterus can be

II. TABLE OF MEASUREMENTS OF ADULT C. AMERICANUS

Structure measured Male Female

HIB ery Gir eo ene ae Le We RAN RU SOMA AIDE RE Ln 4.9-11.3 7.4-19.4

NGTeCUEESE WAGs ee fed Ss se RL Es ee 0.15-0.27 0.16-0.46

Raionwidthytoleng thst yee eee eh eel 1:26-1:49 1:33-1:64

IV ENIS ETOH POS VULVA era Miy seco Ned eee) Segeu noes eee A ease ee ga ae 3.2-10.4

[ CASvayeg Wan Toy ce\tq Whig ho ene Aare i aa a Ya SL RC AE et ad 4.0-9.2

FeatlOLPOSuVULVa (COMPLE VULVA iia Lene ea see 1:0.8-1:1.3

LO cerayet ele Coy 7 Tesi UD RSD AE eR UE er ay ee Oe a 0.14-0.31

Length of anterior portion of esophagus.................. 0.36-0.44 0.39-0.49

Length of posterior portion of esophagus................ 0.41-0.70 0.45-0.70

Thickest diameter of esophagus (anterior)................ 0.086-0.120 0.095-0.131

ene thiv orien tispiculanme: sees. sues OF S40-OK O20 ieee eee cee,

MenecooOr lett spicuiami:.y. vo kee he ea OES TORN a) eevee dBi coe Nee

Length of caudal ew ua Lie SON Sete OQVAS9-ON IOS et eee tee ele

54 T. B. MAGATH

seen to contain motile embryos and some of the coils of the ovary and

oviduct can be made out in the anterior end of the body.

Worms kept in water for twenty-four hours or more, are almost

transparent as the red color of the body fluid disappears, whereupon

the intestine stands out even more clearly.

III. SPECIAL ANATOMY

CUTICULA

The cuticular covering of these worms is not unlike that of other

nematodes in general appearance. Altho the worms are slightly

colored in life, this fact is not due to the presence of coloring matter

in the cuticula itself, but rather to a color present in the body fluid, for

if worms are cut in two this fluid runs out, leaving the worms without

the red color; if kept in water for several days, they get almost color-

less, if kept in blood they do not lose their color. The niaterial of

which the cuticula is composed is, physically, a highly refractive

substance, which may be slightly straw colored. It is elastic and

and when stripped off and moist, reminds one of softened gelatin.

Reports of pigment in the cuticula of nematodes, especially the

parasitic ones, are rare and probably due to misinterpreted facts.

The thickness of the cuticula in these forms varies with the age of

the worms to some extent and is thinner in males than females, tho

perhaps no thinner in proportion to the length of the worms. The

table below gives the average of several measurements made from

average adult males and females.

Region measured Male Female

Region of jaws 1p 3 yp

Anterior third of esophagus S) /p 4 u

Middle of body 4u 10 p

Posterior region of body 4u 9p

Vulva swelling 16 u

Region of alae 4u

Postanal region lu 1p

From this it will be seen that the thickest part of the cuticula is

found in the middle of the body and that at either end the cuticula

is thinned out. There are slight thickenings of the cuticula extending

for a short distance in the anterior region of the body underneath

the lateral cephalic ganglia and just outside of the lateral bands.

CAMALLANUS AMERICANUS NOV. SPEC. 55

As in the case of most other nematodes the cuticula of this form

is striated (Fig. 29), but the striations are not very pronounced.

Striations are seen in embryos which are only 0.542 mm. long. These

markings seem to be more conspicuous in the males than in the

females and in the latter they are deepest in the posterior region.

In the largest individuals these striations are 6 uw apart and half so

far apart in females that are no longer than 4.6mm. It seems

probable that as the worms grow the distance of the striations from

each other grows so that a worm about 9.0 mm. long will have the

same number of striations as the female of half the length; the growth

of the cuticula pulls them apart. So far as I could determine these

striations do not appear below the outer layer, altho Looss (1905)

states that they make an impression upon the subcuticula in An-

cylostoma duodenale.

In C. americanus the cuticula is not made up of a number of com-

plex layers as has been described in the case of the larger Ascaris

species. Four layers are found in the largest specimens and each one

of these is homogenous. The layers have been named as indicated

by the reaction to stains. The thickness of each layer is given as

observed in an adult female.

fe @uterdark layer. 2.2.12: 0.3 uw

2. Outer light layer.................... 4.0 u

33 inner darkwlayer eee 3.0 uw

4. Inner light layer.................... 2.0 u

No fibrous layer (Fibrillenschicht) nor supporting fibers could

be detected within the cuticula, neither could hyaline bodies as

described in Ancylostoma be seen. Each layer is homogeneous within

itself and the only difference that could be detected between the

several layers is their difference in taking stains. The third layer is

divided in the middle by a dark line, indicating that it was laid down

at two different times, or in two layers, this being also true of the

fourth layer (Figs. 26, 27).

In the embryos within the uterus the cuticula is a single

homogenous layer and is a little over one micron thick. In a very

young female about 5 mm. long the cuticula is only 4 u thick and

shows in its structure only the outer two and a half layers. In a

young female, after fecundation but with the embryos mostly in

cleavage stages, the cuticula is 6 w thick in the mid-region of the body,

56 T. B. MAGATH

the outer light layer is formed and is of the same thickness as in the

most mature females, the inner dark layer is in the process of being

formed and the subcuticula is rather thicker than in the older forms

(Fig. 32).

The cuticula is easily stained with any one of the following stains

among others: all hematoxylins, orcein, eosin, acid fuschin, gold

chloride, thionin (weakly) and orange G. It does not stain with

methylene blue or polychromatic methylene blue.

Most authors have used the word “‘chitin”’ for this cuticula and

the name is also used for the covering and other hard parts of animals

in widely separated groups; hence the question has arisen as to the

justification of its usage. There seem to be two distinct meanings

of the term, one of which is morphological and the other chemical.

In morphology the word has been used to cover a great variety of

structures for it is applied to coverings of animals, mouth parts,

spicula, linings of organs, setae, etc. In chemistry the word has been

used to designate a definite chemical compound. Following is given a

brief survey of the usage of the word, especially as regards the group

of worms, and from this I am inclined to reserve the name for those

parts or organs which are chemically chitin, and to use other words

for substances which are not of this chemical constitution.

Odier (1832) first used and applied the word chitin to the material

composing the covering of certain insects upon which he was working.

This early worker not only appreciated its physical but many of its

chemical properties, and regarded it as being closely related to the

cell coverings found in some plants. He sums up his results in the

statement that chitin is a substance which is not dissolved in potash;

is soluble in cold sulfuric acid; does not become yellow in nitric

acid (negative xanthroproteic test); does not melt on heating and

does not contain nitrogen.

More recent investigation has supported this first summary of the

properties of the substance, with the exception of the very last state-

ment, there being in the neighborhood of 6% nitrogen in chitin.

It is evident that if the term be considered as a morphological one,

then only the structures which envelop an organism can be called

chitin, while if it is taken in a chemical sense, only those structures

which agree with this substance in the coverings of the insects can be

called chitin, in short, they must be composed of glucosamine and

CAMALLANUS AMERICANUS NOV. SPEC. Sf

acetic acid plus an as yet unidentified nitrogen fraction (Morgulis

1916).

Grube (1850:253) who worked on the cuticular coverings in

various forms, stated that among others, Ascaris was covered with

a chitinous cuticula; just what he considered to be his evidence is

unknown.

It is perhaps due to the authority of Leuckart (1852) that the

misunderstanding concerning the name chitin has arisen. This

eminent parasitologist maintained that the word ‘“‘chitin”’ was a

“‘Collectivbegriff’’ and stated that the cuticula of Ascaris (Nema-

toda) and the annelids was composed of chitin. He further included

in this list many other forms which do not concern this discussion.

Altho he called the substance chitin he knew that it was soluble in

alkalis and that chitin of Odier was not, because he gives the proper-

ues of the two substances in his paper. Other authors have followed

him in his usage of the terms.

Goodrich (1897) recognized a difference in the substance which

composed the covering of certain worms and that of the Arthropoda.

He states that “so far as the solubilites show, the cuticula appears to

be formed of a substance closely allied neither to chitin nor mucin.”’

In addition to this he stated that he obtained a positive xanthropro-

teic and a modified Millon’s test with the cuticula and certain cuticula

appendages of these worms.

Sukatschoff (1899) worked on the cuticula of Lumbricus and

Ascaris. In the former, in which he was particularly interested he

corrected the erroneous statement of Grube, and said that it was not

chitin, but conjectured that it belonged within a group of proteins

known as albuminoids.

Finally Reichart (1902) proposed the name cornein, a name first

used by Valenciennes (1855), for the substance which covers the

bodies of annelids, or most of them and Ascaris, basing his claim on

the quantitative chemical analysis in the case of annelids and corre-

sponding qualitative tests of both forms. With this last investigator

I can agree and present here the results of my investigations. The

form used was Ascaris suum from the hog, since the same

qualitative tests hold good for C. americanus and other nematodes,

the chemical composition of the cuticula is essentially the same in

the entire group of nematodes.

58 T. B. MAGATH

The material was obtained fresh, and prepared by scraping the

cuticula free from the underlying tissue and then washing it thoroly

in distilled water, after which it was dried to a constant weight in an

oven at 70° C. Cuticula prepared in this way gives the following

results in chemical analysis:

It is insoluble in cold water, but goes partly into solution in boiling

water, swelling to some extent in either. It is insoluble in alcohol,

ether, chloroform, or acetic acid, but swells in the last reagent. It

is further insoluble in dilute mineral acids, but will dissolve upon

standing in either concentrated sulfuric or nitric acid. It is soluble

in hot concentrated acids and in cold caustic alkalis, even when only

1% concentrated upon standing and readily when heated to 70° C.

It is soluble in ammonium hydroxid.

According to Burge and Burge (1915) and Reichard (1902) the

cuticula of Ascaris is digested by the action of enzymes; I have not

repeated these experiments but can see no reason for doubting them.

Tests for the presence of uric acid, creatin and urea have been

negative, as have also been the repeated attempts to obtain a reduc-

tion with Fehling’s solution, either before or after hydrolysis.

With Millon’s reagent the test does not result in a very strong red

color and sometimes seen to be totally negative. Xanthroproteic and

Hopkin-Cole tests are positive. With the biuret test a deep purple

color develops like that resulting in the presence of peptones and

gelatin. The test for unoxidized sulfur was positive. On hydrolysis

no tryosin could be detected.

The total amount of sulfur was determined in two samples with

the following results:

Den O 23 Siemens eee 1.25% sulfur

NTE O23 84 ome sence cess coerce 1.16% sulfur

Avera Geli soci he eloeeces 1.20% sulfur

Total nitrogen was determined by the Kjeldahl method and the

two samples yielded:

Te O}2O2 0% omen cn eee 16.90% nitrogen

We O20 Syom sees ele 17.04% nitrogen

AV CTA BO. oeccscesrteceestiveste sees 16.97% nitrogen

A small amount of cuticula was boiled in water for several hours

and the solution filtered. After the filtrate was precipitated with

CAMALLANUS AMERICANUS NOV. SPEC. 59

alcohol and filtered, the dried precipitate was tested for free and

combined tryptophane. No free acid was found but the Hopkins-

Cole test was still positive. A test for cystine was also positive in the

filtrate.

From the foregoing observations it is at once evident that the

substance of which the cuticula is composed is not chitin but an

albuminoid. On closer observation it becomes obvious that chemical-

ly it more nearly resembles the group of albuminoids represented

by collagen, elastin and gelatin than any others in the group. In all

these the total nitrogen is high, ranging around 17 % and the sulfur

is usually above 0.5 % (of course is pure gelatin there is no cystine

and hence no sulfur) altho in my particular samples the sulfur is a

little high. If the total nitrogen analysis is compared with those

offered for cornein in other animals, it will be seen that they all are

very near alike, thus the list below demonstrates.

TOOL Sorgen ee Fremy

DOGG teers Krukenberg

TOGO G oes Krukenberg

161002545 Krukenberg

U0 RARE NE tee Magath

In addition to this the qualitative properties are the same in all

these cases. If one looks a little more closely into the relation of corn-

ein with gelatin, collogen, etc., he will at once be struck by the fact

that with formol all are hardened and rendered insoluble. This is

the basis for the statement (Magath 1916) that formol in useless as a

killing and fixing agent for nematodes, except in one special technique.

The result with the biuret reaction is again significant, the absence of

tyrosin, the swelling phenomenon with acetic acid and water, and the

general physical appearance relate it very definitely to this series of

proteins.

The fact that the cuticula is digested by the action of enzymes, is

relatively low in sulfur and high in nitrogen excludes it from the

keratin series, which is characterized by the opposite properties;

the fact that it has no sugar in combination with it excludes a close

relationship with the mucoids. To compare this substance with

chitin one should recall, the low percentage of nitrogen present in

chitin, its insolubility in caustic alkalis, its resistance to the action of

60 T. B. MAGATH

enzymes and its glucose molecule; these facts make it impossible to

call the cuticula of nematodes chitin.

Attention should be called to a paper by Flury (1912) who presents

some work on the chemistry of the cuticula of Ascaris. The results

agree very closely with these presented here with the exception of

the determination of sulfur. Flury found 4.3 %in his samples which

is much higher than I have found. He concludes that the substance is

keratin, but objections to this conclusion have already been pointed

out.

In conclusion then, the cuticula of nematodes, and as previous

authors have pointed out the cuticula of most of the worms, is

composed of cornein, an albuminoid closely related to the albuminoids

of connective and supportive tissue and is a differentiation product

and not a solidified secretion (Leydig, 1888, and Rauther, 1905).

SUBCUTICULA AND LONGITUDINAL LINES

A. Female

In general, the subcuticula of this species is not unlike in arrange-

ment that of Ancylostoma duodenale as described by Looss.

No nuclei can be found in the very thin layer between the muscle

cells and the cuticula. In the oldest worms no subcuticula layer can

be demonstrated at all except in the thickened areas known as the

longitudinal lines. In some cases the muscles seem to be applied

directly to the inner margin of the cuticula. In the younger indivi-

duals there can be occasionally seen a few strands of tissue, continuous

with the longitudinal lines, and because it lies underneath the cuticula

it has been interpreted as being the subcuticula, but at best this layer

is very poorly developed in C. americanus. Because no nuclei appear

in this tissue it should be considered as being a syncytium which

embraces the longitudinal lines and certain other parts to be men-

tioned in other sections of the paper.

The anterior origin of the four longitudinal lines, there are no

subdorsals or subventrals in this species, is very interesting and at the

same time extremely difficult to work out. Unexplained structures

have been noted by previous authors in the “‘head”’ region of nema-

todes and even in Mermis, Rauther (1906) has described them briefly,

but as will be shown, correctly attributes them to special modifica-

tions on the longitudinal lines.

CAMALLNAUS AMERICANUS NOV. SPEC. 61

Looss (1901, 1905) referred to structures, which from his text

and figures, I consider to be homologous structures in the Sclero-

stomidae and A. duodenale. He named these structures the

‘“‘lizamentum cephalo-oesophageale”’ stating that this was a structure

“sui generis”? and while he admits (1905:53) that the lateral lines

rise slightly in height in this region and offer support for the cells

of the “‘ligament,’’ he mentions no dorsal and ventral connections

with the subcuticula, nor does he make it clear that he considers this

structure of subcuticula origin. His idea of the function of the

structure is set forth in the following statement: (1905:77) ‘‘it is

intended to attach and to secure the chitinous mouth capsule to the

muscular oesophagus.”’ Looss (1901) suggested for this structure a

function in the motion of these parts, thus indicating a muscular

connection.

The description which Looss gives of these structures in A.

duodenale is not very complete, since he himself admits the difficulty

of working out the region on account of the sections breaking out,

due to the hard parts of the mouth capsule, but I am inclined to

believe from the description given, thai in the following parts of

C. americanus I am dealing with homologous structures and not

greatly unlike those in A. duodenale.

Figure 14 shows four pairs of loose granular masses lying in the

angles formed by the lateral plates of the jaws and the tridents.

Passing posteriorly the two members of each pair unite; each pair is

therefore formed by the division of a single structure. This union

takes place just below the anterior margin of the oesophagus. The

anterior ends of these pairs of protoplasmic masses are seen just

posterior to the anterior margins of the jaws. In a series of sections

passing anteroposteriorly, the lateral lines appear just behind the

anterior insertions of the four giant jaw muscles as narrow bands

dividing each right and left pairs. They soon send out tissue which

applies itself around the outer margins of the lateral plates and soon

joins with the median member of each pair of granular areas. A

single large nucleus appears in each lateral line anterior to the begin-

ning of the oesophagus. The lateral lines increase in size as one passes

posteriorly until at the level of the beginning of the oesophagus they

branch out, tissue from them serving to fill in the space between the

esophagus, body walls and the muscle cells. Here three more nuclei

62 T. B. MAGATH

appear in each lateral line. The tissue of the lateral lines is contin-

uous with the end of the esophagus in the young forms, but in older

animals this tissue has formed the esophageal cap and still retains

its connection with that structure. The cap it not smooth but looks

as though it had a scolloped border.

Fifteen micra below this level the dorsal and ventral lines make

their appearances and then in the region from here to the nerve ring,

the esophagus is surrounded by subcuticula tissue which originates

from the longitudinal lines and forms a commissure around the

oesophagus. The mass of tissue is syncytial, but presents very difinite

structures or thickenings around very large spherical nuclei; the rest

of the tissue is chiefly fibrous. Of these thickenings there are five

dorsal and an equal number in the ventral field, the two most lateral

of each represents the united granular masses which extend anteriorly,

the middle one of each five being the inner end of the dorsal and ven-

tral lines. Each thickening has two large nuclei, all twenty nuclei

being contained within a distance of 50 w. Here and there, scattered

thruout this region, are nerve cells which will be considered in

another section. In the middle of this region appear two more

nuclei in each lateral line, making six in each before they divide into

dorsal and ventral halves.

Near the end of this region under discussion appear two ovoid

nuclei in the dorsal line, there are two more spherical ones in the

ventral but further separated from each other. In the region of the

nerve ring the lines present broadened surfaces towards it. In

addition to these nuclei in the dorsal and ventral lines are two others

in each, small and just at the anterior margins of these lines.

This tissue seems to me to represent nothing more nor less ihan

the anterior origin of the subcuticula. It acts in this region as

support, primarily perhaps, for the nervous tissue, but undoubtedly

forms in some manner the esophageal cap and in all probability it

contributes to the mouth parts, which are cuticula products and

should be formed from the same type of tissue as the body covering;

here is where the two structures make intimate contact with each

other. It is impossible to consider this as a ligament for mouth

apparatus and esophageal connection in C. americanus for here the

chief parts of the structure lie too far posteriorly and from Looss’

description this must be true in Ancylostoma as well. Furthermore

CAMALLANUS AMERICANUS NOV. SPEC. 63

there are similar structures in species without hard oral parts and

these interesting thickenings of subcuticula certainly occur in

Mermis.

Roughly speaking the subcuticula fills up the region between the

esophagus and the body wall, the nerve ring and base of the oral

apparatus; this is the tissue seen within this region as so complicated

a structure.

Interesting in this connection is the fact that the position of the

nuclei and number in the various parts of this region have been

found to be constant in all the specimens examined, perhaps as many

as ten in all, but the fewness and apparent individuality of these

nuclei offer no surprising revelations in the field of ‘‘cell constancy”

(Figs. 34, 35, 46-49).

The thickening of the subcuticula forming the dorsal line is by

far the smallest and most inconspicuous of all the longitudinal lines,

but extends nearly the entire length of the body. It begins anterior

to the nerve ring and extends to the posterior tip of the tail. Thru-

out the middle region of the body it becomes so insignificant as to be

entirely overlooked, but posteriorly it increases rather suddenly and

remains rather thick until within a few micra of the posterior tip.

There are in this structure a few nuclei, and below the anus there are

three, equally spaced and rather large. The muscles in the dorsal

half of the body send more projections to this band than those in the

anterior half.

The ventral line is much more conspicuous than the dorsal one,

but like it diminishes greatly in size thruout the mid region of the

body. Anteriorly it begins about at the level of the beginning of the

dorsal line and has quite the same fate in the posterior part, with the

exception of becoming involved with other structures which will be

taken up separately. About the level of the posterior fifth of the body

the ventral line enlarges greatly and is like a flat cushion extending

along the mid-ventral line. In the region of the anus it becomes very

wide and is even more conspicuous post-anally. There are three

nuclei in this region, equally spaced to correspond to the three in the

dorsal line (Fig. 116). Preanally there are nuclei in the ventral line,

but they are very small and far apart. The regions of the lines pos-

terior to the anus have been called the “‘pulvillus postanalis”’ in A.

duodenale by Looss, but little justification can be found for the

64 T. B. MAGATH

continued use of the term, for this region is merely the posterior part

of the dorsal line and deserves no particular name. Special modifica-

tions of this structure will be discussed elsewhere as for example in

the sections on the vulva, rectum, etc.

As in A. duodenale, the lateral lines (Figs. 46, 50, 57, 117) of this

species arise in the anterior region of the body as a thickened region

of the subcuticula which is undivided at first. Looss says that these

lines arise shortly behind the anterior margin of the oral apparatus in

A. duodenale which is also true of C. americanus. As a matter of fact

they seem to begin just posterior to the region of the anterior insertion

of the four giant muscle cells of the jaws; below their poscerior inser-

tions they are narrow but project well out into the body cavity.

Shortly behind their origin the divisional septum is seen and from

thence posteriorly they are divided into dorsal and ventral halves.

Two regions are fairly well marked out in the lateral lines. Around

the outer membrane which covers them on the interior side, the

protoplasm is very dense and granular, in this region and lying

towards the mesiad, there appears as Looss suggested, a tissue of

“softer”? material and ‘‘watery.’’ Often in older specimens this area

is totally devoid of stainable material and when there is material

present it is not unlike that which precipitates in the body cavity.

Around the ‘“‘partition wall” the protoplasm is thickened; no nuclei

appear either in this region or in the inner area. In the part of the

lateral lines applied to the inner margins of the cuticula one recognizes

the second region. In here are found nuclei, rather large and frequent

in distribution, especially in the posterior region of the body. The

tissue is decidedly of the nature of a syncytium and very fibrous in

character, the Stiitzfibrillen originate here, and in larger species have

been traced out into the subcuticula and into the muscle cells; in

this form the structures are too minute to be demonstrated if they

exist. Occassionally a nucleus is seen at the outer base of the “parti-

tion wall’? and these nuclei are believed to belong to the structure

K. C. Schneider (1902) speaks of as a row of cells, “‘ mediale Zellreihe, ”

in Ascaris, being homologous in these species.

During the course thruout the length of the body, no special

details of the lateral lines need mention; in older females they become

compressed as the uterus fills with embryos, but here and there extend

out into the body cavity when not interferred with by other organs.

CAMALLANUS AMERICANUS NOV. SPEC. 65

Near the posterior tip of the tail the lines occupy a large percentage

of the entire circumference of the body and have less “‘ watery’’ mater-

ial within them. They disappear in the subcuticula of the tip of the

tail. In young forms the lateral lines occupy a large percentage of

the body cavity (Fig. 124).

B. Males

The conditions described for the females as regards the subcuticula

and longitudinal lines are almost duplicated in the males, but with

some slight modifications, chief of which are due to the apparent

displacement of the lateral lines in the posterior region of the body.

These are located so that they appear to lie on the dorsal wall, but in

reality this is not the case. The enormous development of the

muscles of the male tail takes place entirely below the lateral lines,

i.e.. in the ventral half of the body, which causes them to appear far

dorsal, so that they no longer divide the body into approximately

equal halves. The arrangement of the parts of the subcuticula in

the posterior region of the body below the anus is like that in the

females.

THE EXCRETORY SYSTEM

Altho Bojanus and Cloquet (1824) noted the presence of canals

in the lateral lines of nematodes, it remained for von Siebold (1838)

to attach a significance to these organs, and it was he who first noted

that they were connected with a duct which opened on the surface of

the body. He however admitted the puzzling nature of their func-

tion: “Zu welchen Zwecke das in diesen Organen abgesonderte homo-

gene und farblose Sekret dienen soll, wurde noch nicht ermittelt.”’

Subsequent authors up to the time of Schneider (1866) added nothing

of value to the observations of von Siebold and even Schneider was

able to make only a few guesses as to the true nature of these organs.

About this time the work of Bastian (1866) appeared in which he

stated that the whole structure came from a single cell and compared

the organs to the so-called ‘‘ water-vascular system” in trematodes.

Leuckart added nothing of value to the statements of Schneider, but

upon his authority nearly all workers since have looked for the

excretory function of the nematodes in the lateral lines and the

canals anatomically connected with them.

66 T. B. MAGATH

Stimulated by the observations of Kovalesky followed by Metal-

nikow (1897), Nassanow (1897 to 1900a) investigated this interesting

system by means of injecting certain substances into the body

cavity and observing the results. The second of these authors

mentioned obtained chiefly negative results; in only two instances

did he observe the massing of the stains; he used suspensions

of carmin, etc., within the lateral lines. However, he noted

the appearance of certain stains in the cells of the middle intestine

and was forced to the conclusion that while the lateral lines may

play some part in the excretory function, the gut itself must be quite

a factor in the elimination of certain materials from the body. Nas-

sanow repeated the experiments and also noted the action of the

midgut, but was able to detect the presence of frog’s blood, when

injected into the body cavity, within the canals themselves, and so

attached some importance to these structures. He, it was, who

investigated the phagocytic organs, and came to the conclusion that

they are like lymph glands, giving rise to ameboid cells which pass

through the body cavity, collecting foreign materials and destroying

it. He is not very clear as to the final elimination of the destroyed

materials, but one may surmise that this also passes through the

lateral canals or gut wall.

Golowin (1902) carried on a very extensive investigation of the

problem and his results, so far as the excretory system proper is

concerned, may be summarized as follows:

1. Most of the stains used by the former investigators are precipi-

tated in the body cavity, and hence their negative results are

explained. They must be in solution before they can get into the

lateral canals.

2. When colored solutions are injected they may be watched

as they pass into the lateral lines, canals, and finally out thru the

excretory pore, and the amount of excretion can be determined quan-

titativly by means of the colorimeter.

3. Staining of the lateral lines in the few cases in which it was

noted in the use of suspensions, is explained by the fact that the

animals died first, this is true as well in the case of the staining of the

phagocytic organs, midgut, etc.

4. The lateral lines are engaged in the excretory process as well

as the canals.

CAMALLANUS AMERICANUS NOV. SPEC. 67

Looss (1905) after investigating the cervical glands in Ancylos-

toma came to the conclusion that they represent “integral component

parts of the excretory apparatus,” and not glands, but he wisely

reserved his final decision of the whole matter until further investi-

gation of the system has been made.

One year later Goldschmidt, (1906) in his characteristic dogmatic

way, gave his conception of the system. It arises from a single cell, a

radiating nucleus lies in the left leg posterior to the arcadelike portion.

The canal is lost in a circle of nuclei in a smaller canal, which itself

then narrows before a nucleus. The two lateral canals, lying in the

lateral lines, connect in the anterior part of the body thru an arcade,

called a ‘‘bridge.”” There is in Ascaris some complications of the

canals in the anterior region, of no importance here, but finally an

exit is made by means of a single ventral pore. Posteriorly the lateral

canals end blindly. The lining of the canals is difficult to describe,

but looks something like glass. There is around this inner lining a

plasmatic substance, but neither of these structures suggests in the

least the excreting cells of other forms. The tissue on either side of

the canals in each line is glandular in nature, and Goldschmidt

thought that he had recognized an excretion from them into the

canals themselves, thru small pores. The lateral lines in part then,

are excretory in function and the syncytium around them is a passage

way for materials going into the canals.

The research of Rauther (1907) is very interesting in a compara-

tive way. He concerned himself with the free-living nematodes

and after working with indigo carmin, found that whether it was

taken in by the mouth, e.g., with food, or thru the skin, that the

excretion was indirect. It was finally excreted thru the gut, which

he compared to a urinary duct, and the esophagus, which he compared

to the Malpighian capsules. He eliminated the glands of the esopha-

gus as functioning in the process and found that the process was

carried on by the muscles of the organ. The chemicals were absorbed

and eliminated by the gut. He suggested that the pigment masses in

the intestines of certain parasitic forms were stages in the excretion

process.

If Goldschmidt and Rauther are both correct it is interesting to

note that there is a marked difference in the method of elimination

of excretory products between the free-living and perasitic nematodes

68 T. B. MAGATH

and such forms in the parasitic groups as do have no lateral lines

and canals, or only poorly developed ones, present interesting cases.

It occurred to the author that there must be forms present in which

the function is divided between the alimentary canal and the lateral

lines, but may function or there may remain some indication of

function in either case. The species used in this work at once sug-

gested a possibility, from the anatomical relations of its parts. In

the first place there is a divided esophagus, the most posterior portion

of which it histologically quite different from the anterior portion.

Textfigue A.

Diagram show-

ing the general

arrangement of

the excretory

system. 0b. ex-

cretory bridge;

b.c. eXcretory

bridge cell; c.

carrying cell of

excretory duct;

d. excretory

duct; /. lateral

excretory canal.

In the next place the bridge is in the region of the lower

part. Finally this portion is covered with an out-growth

from the tissue of the lateral lines.

In C. americanus the canals themselves lie in

the lateral lines, in a V-shaped area formed by

the union of the dorsal and ventral halves, which

is turned towards the body cavity. Here there

is a thickened portion and very granular, but devoid of

nuclei (Fig. 57). These canals are in the lateral lines

since their inner boundry is always seen between the

canals and the body cavity, except where they leave to

form the bridge, to be spoken of later. The canals

begin in the posterior third of the body as blind tubes

and pass forward to about the level of the anterior fifth

of the posterior part of the esophagus, where they each

bend towards the ventral line, anastomosing with each

other; then there passes, anteriorly and slightly to

the left of the median line, a small duct, which after

making a sharp turn outwards and mediad, opens about

0.35 mm. from the anterior tip of the body and between

the later cervical papillae and the nerve ring (Fig. 50,

also Textfig. A).

The histological details of this system in nema-

todes have been discussed by the previous workers

of whom K. C. Schneider gives a correct account of

the condition in Ascaris: that in C. americanus is not

greatly different except in certain features. It seems

well to consider the canals being composed of two

CAMALLANUS AMERICANUS NOV. SPEC. 69

layers, the inner of which is highly refractive and of a substance

recalling the cuticula from which it is believed by most authors

to have been derived; it must be stated that it stains differently

and does not seem to be continuous with the cuticula in the

adults. To this statement must be added that the mechanics

of getting this long bifid tube lined by the invasion of cuticula

thru a very minute pore at one end is not at all easy to explain,

and the suggestion that it is lined with a_ transformation

product from the outer layer of its own wall is not an unreasonable

one; in the absence of absolute embryological evidence for either

position the latter seems as plausable as the first suggestion. The

outer layer (sarc) is almost as monotonous as the inner. This layer

is granular in nature, stains with the cytoplasmic stains much more

intensely than the lateral lines, and often has init rather deeply stain-

ing granules, which stand out sharply. These are nearer the

periphery of the wall than the lumen, which is about one to two micra

in diameter.

Perhaps the granules have been mistaken by some authors for

nuclei and would account for the statement made by Shipley (1910)

that there are nuclei in this layer. One is unable to find the best

authors considering this as a nucleated layer and it has been shown

that the whole structure proceeds from a single anterior cell.

As the ducts pass anteriorly they enlarge, especially does the wall

get thicker, while the lumen enlarges but slightly. Ata level with the

anterior margin of the intestine the entire duct is, in the females,

about 8 win diameter, while just poserior to the bridge it is 10 yu.

At a position which varies within a distance of the level of the

anterior fifth of the posterior region of the esophagus, the right and

left canals bend towards the mid-ventral line and here lie in a thick-

ened portion of the wall of the ducts, in a substance known as the

“bridge” (Figs. 3, 51,56). Lying to the left of the mid-line is a single

large nucleus, oval or nearly round in shape, and 15 u in diameter,

containing a nucleolus 5 in diameter. The tissue of the bridge is

continuous with the outer layer of the canals and of the same histo-

logical properties, within it can be seen the minute lumen of the

duct and the inner layer of refractive material. On the ventral side

of the esophagus where the bridge lies, the two are in close contact

70 T. B. MAGATH

with each other. The only wall existing between them is that of the

tunica propria of the esophagus, and in some specimens even this

cannot be detected. In either event the bridge partially encloses the

esophagus on the ventral side. Furthermore, there is enveloping the

whole of the posterior region of the esophagus a tissue (Figs. 31, 33)

not unlike the outer layer of the canals and which seems to be made

of a tissue from them and partly from the inner margins of the lateral

lines. A small nucleus can be seen in this tissue between the left side

of the esophagus and the inner portion of the lateral lines below the

bridge.

Where the duct turns to open to the exterior, there is a nucleus

(Fig. 50) which is located just on top of the duct and medial to it.

This is considered the nucleus of the carrying cell of the excretory

vesicle and this cell envelops the canal in this region. It probably

functions as a supporting cell as well, since no other cell is present.

The rather suggestive histology of the posterior portion of the

esophagus and the lack of excreting tissue with nuclei in the lateral

lines as in the case of Ascaris, together with the fact that the bridge

and the accessory tissue are so closely associated with the esophagus

has led to a conclusioa, which if true, has some bearing on conceptions

of the excretory function of these forms.

The bridge is so closely associated with the esophagus that the

latter stands in the same relation to the lumen of the canals as do the

lateral lines, and I believe from the nature of the structure of this

portion of the esophagus, that it has to do with the excretory function,

that the excretory products instead of passing thru the lumen of the gut

as Rauther found in the case of the free-living nematodes, passes thru

the tissue of the esophagus and then into the lateral ducts in whatever

fashion this could take place in the lateral bands, whether thru min-

ute pores or by absorption, in which event hydrophylic proteins or

their derivitives should be looked for as agents. Under the last

condition the thin lining will have to be permeable, which would

increase the possibility of this system being excretory.

If one allow that the posterior portion of the esophagus can and

does act as the excretory apparatus in part or in the whole, these

forms will be intermediate between the free-living and the more

highly developed parasitic nematodes, so far as this function is

concerned.

CAMALLANUS AMERICANUS NOV. SPEC. 71

It is rather interesting to note in this connection that most of the

nematode parasites so far recorded from water hosts are characterized

by the possession of two or more regions of the esophagus, ceca, etc.;

forms which are found in both water and land hosts have, to a great

extent, an esophageal bulb, with this group are numberous nematode

parasites of insects which live in moist decaying material, and some

hosts which spend part of their lives in the water; the strictly land

parasites have usually a simple esophagus. It is not unreasonable to

suppose that the first forms to become parasitized would be the

water hosts, since the free living nematodes are mostly found in water

or mud. If this be true one would expect the nematodes of these

hosts to be closer related to the free-living forms than those of the

land hosts. Itis an interesting speculation and one with some founda-

tion, to suppose that these forms found in the water hosts represent

forms that stand below the bulbed esophageal species, e.g., the

Heterakidae, which in turn are below the forms with the type of the

esophagus found in Ascaris, so far as parasitism is concerned. These

more primative nematodes have retained in part, if not entirely,

the function of excretion within the esophagus and are in this respect

but slightly more advanced than the free-living species. Interesting

are the various members of the Superfamily Spiruroidea, in which

one can find varying degrees of esophageal division, some of which

have been pointed out by Ward and Magath (1917).

Finally in this connection should be mentioned the rather

peculiar group of Trichosyringata, in which the esophagus is not

muscular but composed of a capillary tube, passing thru a row of

cells. These forms have very small lateral lines and Rauther (1906)

has maintained that in Mermis, a form he has studied, that the

“‘spindelformigen Zellen des hintern Oesophagus” are the ‘“‘Excre-

tionzellen”’ of this form and are homologous to the ventral bridge cell

in Ascaris. Camallanus americanus then would lie between the two

great groups proposed by Ward. Stephens (1916) suggests an excre-

tory function for certain ‘‘skin glands” found in some nematodes

in the group of Trichosyringata, but Rauther’s suggestion seems

better founded both on fact and theory.

SOMATIC MUSCULATURE

The somatic muscles begin anteriorly on a level with the ring of

the’ mouth apparatus. Here they first appear on the dorsal and

ies T. B. MAGATH

ventral sides of the body, closely applied to the cuticula and between

the fields marked out by the tridents. The lateral fields are still

occupied by the four giant muscle cells which open the jaws. Three

cells between each median and lateral branch of the tridents come

into existence at once, so there are three cells in each quadrant, the

one nearest the lateral margin being nearly twice as large as either

of the other two. A few micra posteriorly three other muscles enter

each field, the large cell in each case being pushed laterally, so that

the last cells enter between them and the mid-dorsal or ventral line,

as the case may be. Other cells enter shortly and the giant cells in

the lateral lines are quickly undermined by the fibrillar portions of

the general body muscle cells, which are large cells of the same size

as those previously mentioned. At the level of the nerve ring there

are, if one quadrant is considered, six cells between the first large cell

and the mid-dorsal or ventral line; this cell makes the seventh, and

between it and the mid-lateral line there are two more, of which the

most lateral is a large one. Finally there enters another small one

between the last and the lateral margin, thus making ten cells in each

quadrant. This last muscle cell can be traced to the level of the

anterior margin of the esophagus, where it appears in each quadrant

and as a single fibrillar element. It remains thus until at the level

of the nerve ring it increases in size, takes on the characteristic shape

of the general body muscle cells, and possesses a sarcoplasmic portion

when the similar portion of the giant cells disappears below the level

of the nerve ring. The series of diagrams shows how these muscle

cells originate (Textfig. B).

Textfigure B. Schematic representation of the anterior origin of the somatic

muscle cells a, is the same muscle cell in each figure; b, is the giant muscle cells of the

valves; c, is the same cell in each figure. The lateral lines are indicated as are also

the dorsal and ventral ones, by fine stipling.

CAMALLANUS AMERICANUS NOV. SPEC. 73

On passing posteriorly the differences in the sizes of the various

cells is lost, so that below the level of the posterior margin of the

esophagus they seem to be of uniform size. Processes bend over to

the dorsal and ventral nerves, none were seen going to the lateral lines,

so that a cross section gives the impression that they lean from the

sides towards the mid-lines (Figs. 55, 123). In the posterior region

this tendency is even more marked, where the processes can be seen

very clearly and to come into contact with the nerve, especially the

ventral nerve. As the cells are anteriorly of about the same height,

the appearance is that of an even circle when seen in cross section,

formed by the tops of the cells (Fig. 51).

Posteriorly the number of cells diminishes, first in the ventral

fields, so that there are but two in the ventral quadrants and four

in the dorsal ones, at the level of the anus. Posterior to the anus

they are diminished further, until in the tip there are finally but four

muscle cells, one in each quadrant.

In the males the somatic muscles in the caudal end are evidently

modified to be useful in the act of copulation (Figs. 87, 92).

Beginning about the level of the lateral alae the fibrillar portions

of two regions of the somatic muscles elongate towards the body

cavity. The two regions are found just ventral to the lateral lines

on the one hand, and on the other hand just lateral on either side

of the ventral line. At first only one or two muscle cells are involved

and so a corresponding cell from each region on the same side comes

to have its fibrillar portion connected and thus there extends a muscle

from a ventral-lateral to a lateral-ventral position, a cross section of

the body presenting the appearance of oblique muscles on either

side of the ventral field. More cells become involved as one passes

posteriorly so that there are about as many bridging the gap as are

left between the two places of insertion. This means that there are

more than a fourth of all the muscles of the caudal end of the body

involved, since the lateral lines have already been pushed far dorsally.

The nuclei of these cells are surrounded by a small amount of proto-

plasm, in the center of the cell. This condition continues even a short

distance below the anus, then the regular somatic muscles continue

and end in the same manner as in the case of the female.

Action of the muscles in the caudal end of the males. The diagram

(Textfig. C) shows the mode of action of these muscles. Their con-

74 T. B. MAGATH

Textfigure C. Diagram illustrating the action of the caudal muscles of the male.

The dotted lines indicate the position of the alae when the muscles have contracted

pulling up the ventrum of the body. By this method the male grasps the vulva of the

female.

traction raises the ventral side of the body. Normally the lateral

alae stand out from the body of the male leaving qvite a little space

between the right and left alae, but when these caudal muscles con-

tract they pull the ventral side of the body up thus serving to bring

together the two lateral alae. These muscles are antagonized by the

elasticity of the body cuticula, and when they relax the lateral alae

are again allowed to swing outward. The usefulness of this arrange-

ment is clearly seen in the act of copulation. Here the male comes

to lie at right angles to the female and with the alae stradling the

vulva (Textfig. D). Then the caudal muscles contract and this pulls

Textfigure D. Diagram showing the position of the male and female during

copulation.

in and down the alae, thus forming a firm hold over the two lips of

the vulva, which are suited by their structure to just this sort of

action. The connection is made not by the use of suction nor by the

CAMALLNAUS AMERICANUS NOV. SPEC. 75

use of cement, but rather by the mere mechanical grip of the two

wings. Of course the insertion of the spicula—either one or two, for I

cannot say whether the smaller one functions—helps to hold the two

worms together.

Here the methods of copulation as known in the Nematoda may

be briefly reviewed.

(1) The action of cement and a bursa. An example is found in

Ancylostoma, where the bursa opens and closes by the action of

special muscles and also furnishes a broad surface for the application

of cement, which is the chief means of holding the male against the

female.

(2) The use of asucker. An example is Heterakis in which a large

sucker exists in the male and is used to attach it to the female. The

action of this sucker, according to Schneider, is effected by a series

of muscles radiating from the bottom of the organ to the edges of the

lateral lines. Their contraction creates a small vacuum which is

released after copulation by the action of the fluid of the body.

(3) The case given in this paper, where a mechanical grip serves

to make the male fast to the female.

There are undoubtedly other means of copulition in the nema-

todes, but no others are sufficiently well-known to be given here.

These three methods are dependent upon certain distinct morpho-

logical differences in the anatomy of the forms in question and

presents an interesting field for research which may lead to a good

means of classification. The vulva of the females will also need to be

studied for it may furnish a clue, because it is modified according

to the modus operandi of the males.

Histology of the somatic muscle cells. These cells are, like the

muscle cells of other nematodes, composed of two portions, the fibril-

lar and sarcoplasmic. In the cells of the anterior region of the body,

anterior to the posterior margin of the esophagus, the latter portion

is larger than the former, while in the rest of the body they are of

about equal size. The fibrilla part is in the shape of a V or U, with

the notch varying in depth from a barely perceptible one, until in

some cells, it appears to cut in half the depth of the outer layer. In

the fibrillar layer the muscle bands (Muskelleisten) are placed very

closely together so that it is not possible to count the number accur-

ately, altho they are estimated as being nearly one hundred in each

76 T. B. MAGATH

cell (Figs. 25, 28). Supporting fibers (Stiitzfibrille) cannot be seen

in this layer. The muscle bands are arranged along three faces of the

cell, on the face nearest the cuticula and on the two vertical sides, so

that the bands come together in a sharp angle in two diagonal lines.

A little thickening of the protoplasm occurs around the margins of

the cells. The sarcoplasmic parts of the cells stick out into the

general body cavity, somewhat beyond the inner margins of the

fibrillar layer. In this portion one can see a very large nucleus, oval

in shape and 6 u long, containing but one nucleolus, which is rather

large and stains deeply with hematoxylin stains. Around the nucleus

is a dark staining area, the “‘ Gitterk6rbchen”’ of Bilek (1909), which

he has shown to be made up of the supporting fibers of the cells, and

from this area, in well preserved specimens can be seen very minute

fibrills, which can be traced out thru the sarcoplasmic part of the

cell. They probably pass into the contractile layer and thence into

the subcuticula as Bilek (1910) has shown in the case of A. lumbri-

coides and megalocephala. ‘The sarcoplasm consists of fine granular

material, which stains a light red with van Gieson’s stain and blue

with Mallory’s and Delafield’s hematoxylin.

The fibrillar portion stains with picric acid and the anilin stains, or

with chrom-hematoxylin. The bands stain but slightly darker than

the ground substance of the fibrillar layer.

The anterior cells are perhaps no longer than 0.2 mm. while

posteriorly the cells are as long as 1 mm. in some cases. A typical

anterior cell is compared with a typical posterior one in the following

table:

Place of measurement Anterior cell Posterior cell

Width 0.013 mm. 0.013 mm.

Thickness 0.020 mm. 0.015 mm.

Thickest part of sarcoplasma 0.016 mm. 0.008 mm.

The muscle cells of this form are very much like those of Ancylos-

toma duodenale as described by Looss (1905) both as regards size and

structure. It is interesting to note that while this is true, there are in

the hookworm only eight cells around the body as seen in cross sec-

tion, while there are about forty in the new species. As in the case

of A. duodenale there may be several sarcoplasmic processes from

CAMALLANUS AMERICANUS NOV. SPEC. 77

each cell, and these also anastomose with each other, and seem in

some cases to come into contact with the internal organs.

As compared with the muscle cells of Oxyuris curvula (Ehlers 1899)

they are quite different. Here the cells are 8.69 mm. long and

0.51 mm. wide. There is next to the subcuticula a flat layer of

contractile material, then placed on this is a granular unstainable

portion, and finally an intensively staining rind layer. Each muscle

cell has a nucleus.

The type of muscle cell in the larger members of the genus Ascaris

is so well known that it needs little attention here. The contractile

portion is in the shape of a very deep U with the sarcoplasmic portion

extending out from it and containing a large nucleus with its accumu-

lation of supporting fibers around it. These fibers pass into the

ground substance of the contractile part and finally into the subcuti-

cula. The sarcoplasmic layer is in contact with the fibrillar layer

nearly all the way down to the bottom of the U, which is very near

the subcuticula layer. The diagram illustrates the three conditions

mentioned above (Textfig. E).

Oxyuris Cammallanus Ascaris

Textfigure E. Diagram illustrating the relative amount of Sarcoplasmic and

Fibrillar portions of muscle cells in different nematode genera.

Schneider (1860) proposed two names to be applied to divisions of

the Class Nematoda, based on the structure of the musclecells. The

name ‘‘Platymyarier’’ was applied to all nematodes in which the

fibrillar portion of the muscle was flat towards the body cavity,

typically in the case of Oxyuris. The ‘‘Coelomyarier’’ include the

nematodes in which the fibrillar portion was notched so that the

sarcoplasmic part dipped down into and between the contractile layer,

which was present on either side of the cell and on the outer margin.

Further Schneider recognized a difference in the muscular system

of Gordius and Mermis and he (1886) proposed the name Holo- —

78 T. B. MAGATH

myarii to include these forms along with certain other Nematoda.

However, Biitschli (1873) showed that this division was unwarranted,

and so the term must be rejected.

Cognizant of the fact that there were forms in which the muscle

cells because of their great variation could not be accurately placed in

either the group of Platymyarians or Coelomyarians, and further

that some worms were found in which the cells were different in

different parts of the body, Schneider (1863) proposed to abandon

these original names and use instead Polymyarii and Meromyarii,

basing his classification on the number of cells that appear in a cross

section. In the former, as the name signifies, many cells occur, in the

latter there are only eight, or two in each quadrant.

It is evident that C. americanus is a Polymyarian on this basis and

on the dividing line as regards the original groups. Ancylostoma

duodenale stands about on the level with the new species as regards

the type of cell, but is a Meromyrian according to the division of

1866.

A discussion of the advisability of continuing this classification

will be found in the section on systematic position of the form, but it

is interesting to note here that Martini (1909) states that all Poly-

myarians studied by him have many cells in a cross section of the gut,

but, while there are many Meromyarians with an intestine composed

of only two rows of cells, there are those in which the intestine has

as many cells in cross section as in any Polymyarian, e.g., Oxyuris.

SPECIAL MUSCLES

The intestinal muscles. The intestinal muscles (dilators) in the

female arise about 0.4 mm. from the anterior end of the rectum and

extend to that level. They arise as four separate bundles of fibers,

each about 7u in diameter. After a rather long insertion on the

inner side of the cuticula, pass down diagonally thru the body cavity

to run posteriorly along the side of the intestine, one at each “corner,”’

so that they lie, two in the dorso-lateral and two in the ventro-lateral

fields (Fig. 118). Their anterior insertions are in each quadrant just

between the first muscle cell to the dorsum or ventrum of the lateral

lines and the lines themselves.

About half way in their course each dorsal bundle unites with a

ventral bundle on the same side (Fig. 129), so that there is a widened

CAMALLANUS AMERICANUS NOV. SPEC. 79

region on each side of the intestine, curving around it in the shape

of a horse-show. It is in this widened region, on either side, that a

single nucleus is found, lying towards the dorsal side of the place of

fusion. ‘This demonstrates that each lateral pair of fiber bundles

belongs to one cell, which branches anteriorly into two parts. Below

this anastomosis of the two bundles, each cell branches out (Fig. 120)

and these fine divisions become attached to the outer wall of the intes-

tine. When the branches become as numerous as ten, there is seen

covering all of the branches and enclosing the intestine, a thin fibrous

tube (Fig. 123), which binds these smaller bundles of the intestinal

muscle cells to the intestine. This tube of fibrous material extends

to and is continuous with the fibrous element of the sphincter muscle

cells, becoming along its course much thicker than at its beginning.

Near this region there appear two nuclei, one of which is always more

posterior and lies a little to the left of the mid-ventral line, (Fig. 125).

The outer varies in position but is usually dorsal in location (Fig. 126).

In the section on the rectum a more complete account of these struc-

ture will be given, but here a few words are necessary. Looss has not

mentioned the existence of such a fibrous tube as here described, but

has stated that there is a sphincter, muscle composed of a small

number of fibers and a single nucleus in Ancylostoma. It seems

probable that this tube here described in reality is the sphincter,

greatly developed and serving as a means of effecting a good insertion

for the intestinal muscles, as well as for the constriction of the lower

portion of the gut. The second nucleus may have been overlooked

by Looss or may be present in C. americanus on account of the greater

development of the sphincter.

Branches from this tube pass over to the ventral line and some few

to the lateral lines, and undoubtedly carry in them the nerves to

supply this structure. Just in front of the rectum one can count as

many as thirty-five branches spreading out all around the intestine,

and these are held in place by the fibrous tube, and partly, by the

fusion to the gut wall in the very posterior region.

As to the function of these fibers which go to the intestine a word

should be added based on their position and insertion. I believe

that they oppose the anal muscles in part and the sphincter muscle

as well. Their contraction would raise the intestine and at the same

time expand its lumen, the anal muscles by contraction would pull

80 T. B. MAGATH

down the gut into position and the sphincter would close it. The

sudden elevation of the gut and expansion of the lumen would of

course act to expel the intestinal contents. There is no evidence to

show that peristaltic movements occur in the guts of nematodes.

A continued contraction of these muscles would tend to inroll

the tail, a fact taken into account in the discussion of the musculus

ani. Looss states that the branches of these muscles which partly

encircle the gut in A. duodenale, by contraction would not only open

but also close the gut, an action which would be hard to conceive in

any case, much less in C. americanus. In Ascaris these muscles are so

placed that it would be impossible for them to close the gut, for here

branches radiate all the way around the intestine and are inserted

on the cuticula (Voltzenlogel, 1902).

In the males, the intestinal muscles are not so well developed as

they are in the females, and are much shorter. They are anteriorly

inserted a little above the level of the beginning of the caudal muscles

and have their posterior insertions effected by branching out over the

intestine just above the rectum. However, the branches are by no

means so numerous as in the case of the females.

Musculus ani. Altho Looss described this muscle correctly he

called it ‘“‘musculi anales”’ for which I can see no justification, since

it is clearly one muscle and furthermore composed of one cell, which

fact Looss points out; no one would speak of a biceps as being “ mus-

cles”? simply because it has two places of origin.

This muscle is present in the females only and is in the shape of a

fan, spreading out antero-posteriorly as well as laterally. One inser-

tion of this muscle is along the dorsal side of the rectum in its posterior

sixth, immediately above the anus. From here it spreads out in all

directions, (Figs. 8,113,119), but with the main divisions running on

the right and left sides of the body, these in turn break up into

branches which are inserted on the inner side of the cuticula between

the regular somatic muscles. Previous authors have called attention

to the peculiar shape of this muscle, which is roughly that of the

letter H, for between the two places of insertion there occurs a narrow

strip of sarcoplasm in which is present a large spherical nucleus

(Figs. 113, 119), demonstrating that the structure is really composed

of a single median cell.

CAMALLANUS AMERICANUS NOV. SPEC. 81

The action of this muscle has been indicated in the section on the

intestinal muscles, and only a word need be added here. When the

gut is elevated and opened by the latter muscles, the body is inrolled

to some extent, this being true when the feces are expelled, when the

musculus ani contracts, its broad outer insertion allows it not only

to pull the gut down into place but to straighten out the tail as well.

Thus these two sets of muscles are even more closely related to the

general somatic muscle cells in function than has been suggested by

previous authors. The function of this cell is taken over in the male

by the modified caudal somatic muscle cells.

THE DIGESTIVE TRACT

Altho the oral apparatus of the genus Camallanus is so very

characteristic and prominent, none of the previous writers have

given good descriptions of the parts or have interpreted their func-

tions aright.

The earliest description which was available to the author was

that of Rudolphi (1809) who wrote of the structure in the following

manner: The mouth (the principal food passageway) is globular

and longitudinally densely striated, with a posterior apophysis, short

and extending transversely, which seems to end in two short internal

hooks, obtuse and incurved. There are two other external, longer

and decurrent ones; or if the total apparatus (vasa) is short, the

hooks seem to be set into the intestine. As for the shell (cucullum)

itself, it does not entirely fill up the body, a part is empty and appears

clear, which is called the clear spot (macula pellucida), a peculiar

organ but not considered.

The next author to describe the structure was Dujardin (1845)

and his meager account of the apparatus of manducation is that it is

formed of a shell, with a short transverse bar at its base, and two

intermediate pieces forming a longitudinal body with two or four

divergent, oblique and posteriorly directed branches.

In Schneider’s monograph (1866) appears the following descrip-

tion: The mouth is slit right and left, occupying the entire region

of the head; it is built into a thick capsule, somewhat elliptical, more

circular posteriorly and opening into the esophagus in a cross-shaped

opening. On the internal surface of the capsule occur a number of

ridges or teeth, parallel and forming small teeth on the margin of the

82 T. B. MAGATH

buccal orifice. The sides of the capsule are not equally thick; in the

anterior part of each side, they are reduced to a thin membrane.

The dorsal and ventral portions, which are brown and thick, give to

the eye the appearance of two opposed shells. Behind the capsule,

on each side, one sees an apparatus of three branches, made of the

same substance and continuous with the shells. These prolongations

are morphologically, and without doubt physiologically, of the same

nature as the apparatus with the three branches in Filaria pungens,

which they resemble. The trifurcated apparatus is situated, not in

the esophagus, but outside of it.

Perrier’s description (1872) is more lengthy and while superficial

and incorrect in some respects, gives the best idea of the structure.

His figures are copied in Plate XVI. He writes: In the first place

the two buccal valves are very evident and are not simple in appear-

ance, due to the thickening of certain parts of the capsule, analogous

to the cephalic capsule of the strongyles and related Nematoda.

These valves are perhaps joined to each other by a ligament as differ-

ent bones are joined; no one would consider two adjoining bones as

having been formed at one and the same time, so in the case of the

capsular articulation. I believe that the formulation of the opinion

of our adversary of the present moment, Schneider, allows the

entertainment of strange, preconceived, morphological ideas held in

regards this genus and the strongyles.

Each valve is composed of a part, more or less semi-elliptical,

concave towards the interior and situated anterior to the esophagus:

it is the active part of the mouth; inferiorly this part is prolonged

into a sort of median point, rectangular, short, somewhat transparent,

and engaged in the esophagus where one can easily distinguish it.

On each side, the two valves are separated, the one from the other,

by a chitinous nodule on which they are simply supported by their

inferior angles, and is not made in so sharp a fashion as the body of the

valves; on the inferior side this nodule rests on the superior margin of

the esophagus. It gives origin to two kinds of chitinous structures:

(1) Three lateral branches which are spoken of by other authors.

(2) Two transverse chitinous bands, a superior one, and a ventral

inferior one.

These chitinous bands unite the two nodules, making an abso-

lutely firm contour. Each band is formed of three parts, of which

CAMALLANUS AMERICANUS NOV. SPEC. 83

the two laterals are convex towards the exterior, while the middle

scallop, weaker and less colored than the other two, is convex towards

the interior and supported at its summit on the middle of the inferior

border of the corresponding valve.

These are the analogues of the two chitinous bands, which Rudol-

phi wished to call the apophysis, as he designated this transverse bar.

Unfortunately, the peculiarities presented by this bar in the species

under discussion are not recognized, and its physiological réle has

completely escaped helminthologists in illustrations, as it has escaped

those who have occupied themselves with the form from the perch

only.

The lateral branches are three in number on each side; with a

length of 60. Of these branches one is median and unpaired on

each side; the other two are symmetrical and formed in consequence

of a sort of angle which the median branch bisects. This last branch

is straight, pointed at its summit, oblique from before and behind,

and from within outwards, in respect to the axis of the body; it is

found immediately in contact with the sides of the body, which it

serves to support. The other two branches are strongly curved and

divergent, one is high and interior, the other low and largely exterior.

It is a little underneath their junction with the chitinous nodule from

which the apophysis arises. Each of these nodules terminates in a

large swelling of chitin, in which is inserted a large muscular cord,

which passes from before backwards and from without inwards

towards the axis of the body. One can distinguish very clearly four

muscular cords among the longitudinal muscles of the body and

among the cords which unite with the esophagus, with the sides of

the body and the chitinous branches themselves.

Perrier thought that if the muscles attached to the posterior tips

of the prongs should contract, they would tend to pull together the

posterior tips and because the middle scallop was weak it would give

in, allowing the anterior margins of the valves to be sprung open.

When these muscles were relaxed the simple elasticity of the material,

it being under compression, would cause it to resume its normal shape.

Outside of this explanation, which will be shown to be totally incor-

rect, there is in literature no explanation of the action of these parts,

so far as my information goes. Before going into that it is necessary

to give a full account of the exact morphology of the parts of the

84 T. B. MAGATH

oral region. Judging from either the text or the figures of the earlier

authors, there is some confusion as to the position of the two lateral

valves, as I shall designate the most prominent structures of the

mouth region. Altho it is difficult to tell from the poor figures

given by Rudolphi, and there is no statement in the text, it seems

probably that he considered the valves as being dorso-ventral in posi-

tion. Schneider and Perrier certainly considered them as being in

this position as well as does von Linstow (1909), if one is to judge

from his figures. Railliet and Henry (1915a) give as a generic

character the position of the valves, which they state is dorso-ventral.

Dujardin, Seurat (1915a) and Ward and Magath (1917) have correct-

ly stated that they are lateral, and with this view I agree: reference

to the figures and descriptions will prove this contention.

Authors have applied various terms to the description of these

valves; some are: kappenformigen Mundkapsel (Goeze 1782),

cucullo striato (Rudolphi), coquille (chaperon cucullus Rud.) (Dujar-

din), valves buccales (Perrier), camail d’apiculteur (Railliet and

Henry) and Seurat refers to them as being ‘“‘buccal valves shaped

like the valves of pecten.”? This last phrase very nearly describes

them, for as viewed from the side they present a very close resemb-

lance to such shells, except they are a little more convex (Figs. 1, 2,

3, 4). These two valves, of which one is a right and one left, are

united in their posterior half; a cross section in this region shows a

complete, rather oval-shaped structure of valve substance, (Figs. 13,

16). A section taken more anteriorly shows they are free of each

other, and appear as two jaws (Figs. 12,15). The whole apparatus is

a golden brown color. These valves appear longitudinally striated

which is due to the presence of ridges projecting a few micra towards

the interior. The number of ridges varies a little in different speci-

mens and in the regions of the valves, so that a section taken near the

posterior region will show six ridges and as the sections are examined

anteriorly more ridges make their appearance until there are ten or

twelve in all, divided into two fields, so that there is a little distance

in the middle in which there are no ridges. Near the anterior margin

of the valves these ridges suddenly increase in depth so that the end

shows little hooks formed which project out into the buccal cavity

as rather sharp teeth (Fig. 12). The anterior median margin of

the valves is notched in the shape of a U. From either side of this

CAMALLANUS AMERICANUS NOV. SPEC. 85

notch the anterior margins pass off in a slight curve, which proceed

posteriorly and dorso-ventrally; at the point where the valves are

united to each other is the widest part of the jaws, it being in each

female 0.16 mm, and 0.12 mm. in each of the males. Another curve

which forms the posterior and lateral margin of the valves passes

posteriorly and to the mid-lateral lines; it is along this line that the

two valves are united. Posteriorly (Fig. 14) there is a round hole

which opens into the esophagus. The valves are made up of two

layers, varying in thickness in different regions but around 7 yp, except

along the line of union where they are half so thick. Length: in the

males, 0.089 mm., in females, 0.105 mm.

Around this posterior hole is placed a ring (Figs. 1, 4, 24, 34)

which is made of the same substance as the valves, as all other parts

seem to be. This ring is thin and curved so as to fit down over the

anterior margin of the esophagus. It is about 0.1 mm. in diameter,

and is rather tightly joined to the valves but can be parted with a

needle and then breaks off smoothly. In the fourth stage the ring is

formed, but appears more curved over the esophagus, perhaps when

growth of the esophagus takes place it pushes the ring up and straight-

ens it out, at least it gives one that impression.

Both of these parts described lie well within the body of the worm

and nowhere do they touch the cuticula save at the most anterior

margin, where the valves are in contact with the inner margin of the

thinned cuticula which runs up just over the edge of the valves to end

on a level with their inner surfaces, and again at the widest place in

the valves (Figs. 17, 19).

The third important structures of the oral region are two sets of

three posteriorly directed spikes (Figs. 1, 2, 18) known as the tridents.

These lie one dorsal and the other ventral in position with the post-

erior ends radiating out, so that the total amount of circumference

included between the points of each set in over one-fourth of the total

circumference of the animals body in that region. Each of the tri-

dents is constructed as follows: The anterior margins of the three

spikes are brought together into a solid nodule which is hollowed out

on the interior and fits over the region of the valves where they are

united, this articulation looks very much like that made by the

humerus with the scapula and may be spoken of as a ball and socket

joint, however the juncture must be well made because it is not an

86 T. B. MAGATH

easy task to separate them from the valves, except by special treat-

ment. From this socket the three spikes radiate and about half way

of their length push into the cuticula itself, so that they lie for the

rest of their way in the cuticula, between the two chief divisions, the

points firmly embedded within it (Figs. 46-49). The middle spike

runs exactly mid-dorsal or ventral, as the case may be, and is nearly

square in cross section, coming to a point at its posterior tip, and being

in the males 0.08 mm. long and in the females 0.05 mm. The two

lateral ones are almost oval ia cross section and have a slight swelling

on their posterior ends; they are about the same length as the middle

ones.

Two other kinds of structures are present in this complicated

apparatus. The first of these to be mentioned are the so-called papil-

lae of the earlier authors, and here called the anterior wings (Figs.

1, 2, 4, 15, 22, 23). These are a right and left pair firmly attached

to either valve just posterior to the anterior margin. Each wing is

attached by its inner margin to the valve and the rest is free, extend-

ing laterally for a distance of four to six micra. Their shape is roughly

that of the wings of a beetle and are drawn from a top view and

slightly stretched out in the figures. They are about one micron

wide.

The last structure to be described is the pair of valve covers

(Fig. 20) never before referred to in literature. There is one to cover

each valve and is triangular in shape, with the apex rounded, median-

ally notched and placed anteriorly. The whole structure is very thin,

but apparently made of the same material as the rest of the apparatus.

The sides as well as the base are curved inwards. The two basal

corners are pointed and are weakly attached to the inner margin of the

socket of each trident. The anterior margin is strongly attached to

the anterior outer region of the valves, just below the insertion of the

wings. The covers are curved to fit, and lie closely applied to the

outer surface of the valves.

If worms are treated with concentrated caustic alkalies the entire

worm, including the cuticula is dissolved on standing, or immediately

on boiling, except the mouth apparatus. This remains intact so long

as strong currents do not break it up into its several parts. The

easiest parts to come off and those which do so first are the tridents,

then the covers, then the ring. The wings and the two valves always

CAMALLANUS AMERICANUS NOV. SPEC. 87

remain intact and none of the parts dissolve so far as can be detected

with the aid of the microscope. It should be said that while the head

parts have been kept for days in very hot alkalis they have never been

boiled in experimental tests, since they are so small that it is not prac-

tical to recover them after such radical treatment. It seems evident

enough then that the oral parts are not of the same substance as the

cuticula. The fact that they are not soluble in hot concentrated

alkalis is quite suggestive, as this is one of the chief characteristics

of chitin. Every known test for chitin has been tried on these

structures and each gave negative results, but since these structures

are so deeply colored, I am under the impression that should the

purple tint be formed it could not be recognized. Until enough

material can be obtained to make a chemical analysis I cannot say

what the substance really is. The only absolute way that could be

used to show this apparatus was made of chitin would be to isolate

glucoseaminehydrochlorid from it and this is impossible with the

present method known. The fact that it is soluable in acids makes it

certain that it is not keratin, and considering its color and the fact

that it is insoluble in concentrated alkalis, it seems rather probable

that it is made of chitin.

The last point of interest is how does the apparatus operate and

what is the physiological significance of the whole as well as the parts?

In beginning this answer it is necessary to look at the pathological

picture presented in the intestine of the host. If the intestine is

sectioned with worms still attached it will be seen that the ability

to hold onto the wall is developed to a great extent, which fact is

observed in nature when they are pulled off of the gut for study or

preservation; the amount of traction necessary to dislodge them is

remarkable. Within the mouth and filling up nearly the whole

cavity will be found a plug of intestinal mucosa Figs. 132, 133

the shape of the oral cavity. Where the plug is in contact with the

rest of the wall, the cells show a great degree of distal suction-result,

so that they are compressed and the nuclei drawn towards the plug.

No marked edema seems to occur at the foci and comparatively little

accumulation of leucocytes. At the proximal end of the plug, the

end hooks of the internal valvular ridges are seen firmly embedded

in the tissue.

88 T. B. MAGATH

If a worm is taken from the wall of the intestine and placed with

a piece of the gut under a binocular and watched, it will be seen to

go thru very characteristic motions which finally result in its attach-

ment to the wall. Sometimes this will take place within a few seconds

and the jaws can be seen to open and close; a motion can be observed

whereby the jaws are made to rock upon the tridents. The power of

motion and the ability of the jaws to attach themselves to the intesti-

nal wall is due to the presence of a right and left pair of muscles

(see figures of mouth parts), each composed of two cells, so that

there are four cells in all. In addition to this there is the fact

that the jaws are kept from being pushed posteriorly by the firm

attachment of the tridents and the fact that there is a powerful

suction exerted upon the tissue by the esophagus.

These four muscle cells have the following positions and take

their names from this fact: right dorsal and ventral and left dorsal

and ventral. The anterior insertions of these is at the anterior margin

of the valves, where there is yet no sarcoplasmic process and where

they are closely applied to the wings, which help in supplying inser-

tion surface. Here the fibrillar portion is in contact with the wings

and the valves on the one hand, and with the cuticula on the other,

the muscles being between the cuticula and the valves. Just below

the attachment of fibrillar portion of the muscles, they break away

and thus the most anterior part of the valves is the only place of

insertion, this gives more leverage as will be seen later. The sarco-

plasmic portion appears between the fibrillar portion and the jaws,

and the nuclei of each cell is seen on about the level of the buccal

ring. These muscles extend down the lateral margins on either side

of the very narrow lateral lines, the sarcoplasmic portion extending

a little below the nerve ring and to the level of the lateral cervical

ganglia. The fibrillar portion continues only to the nerve ring.

These cells are enormous as compared with the other muscles of the

body, they being 0.08 mm. wide and the sarcoplasmic process being

0.03 mm. in thickness.

Being longitudinal muscles, on contraction they pull the anterior

margin of the valves open, because the tridents prevent any backward

traction, being firmly held in the cuticula. The thinning of the valves

at the line of juncture, and the fact that they are convex provides a

lever which is made use of by these muscles. If only one pair of the

CAMALLANUS AMERICANUS NOV. SPEC. 89

muscles is contracted the valves will rock upon the tridents and this

motion orients the mouth with respect to the gut wall. Thus attach-

ment is made by the rocking of the valves to get the mouth in posi-

tion, correlated contraction of the two pairs of muscles to open the

jaws, suction by the esophagus, and relaxation of the muscles when a

portion of the gut isia the mouth. Of course the normal motion of the

worm’s body helps to keep the mouth in close contact with the

intestinal wall. Once the mouth surround a plug of tissue, the hold

is made more effective by the anterior hooks, for these work some-

what like the barbs on fish-hooks. The only function of the ring

seems to be that of support, for it furnishes a large surface to fit over

the end of the esophagus.

It would seem then that the explanation of Perrier is in error,

chiefly from the fact that he was ignorant of the exact structure of

the parts of the oral apparatus. The prongs are not connected to a

“middle bar,” but the ‘‘ring”’ really belongs to the valves, is well

joined to them and is developed before the tridents. The tridents

when they are developed come from a region at the extreme lateral

margins of the valves and not from this ring. In the next place there

are no muscles connected to the ends of the spikes of the tridents, an

error carried by Railliet and Henry even in 1915. These are so firmly

embedded in the cuticula that they are not capable of motion and by

this very fact make it possible for other parts to move. The restora-

tion of the apparatus after opening is in truth due to the elasticity of

the structure, but not to “the middle of three scallops’ which do

not exist, but to the elasticity along the line of union of the valves.

Some other points regarding this interesting mouth apparatus in

particular as regards its condition in young specimens, will be dis-

cussed in other sections of the paper, to which the reader is referred.

The esophagus. The esophagus of nematodes has been suggested

by previous authors to be of importance both from a phylogenetic and

an ontogenetic standpoint. This type of esophagus has been said

by many to be characteristic of the group of Nematoda, and so far

only one kind of exception has been found, and that in the division

made by Ward’ (1917) as the Trichosyringata. In this group the

esophagus is a capillary tube, enclosed within a row of cells, a condi-

tion which is not very well understood. The fact that in certain

species at least, the esophagus reaches a maximum length early in

90 T. B. MAGATH

the growth of the individual, makes this organ of some value in iden-

tification and its constancy within a given genus shows that it is

subject to little variation thruout different species within a genus.

Taking it all in all it seems that the esophagus should be considered

as a very important organ in the nematodes, and its shape, size and

structure should be given in descriptions of these animals.

In C. americanus there exist two portions of this interesting organ

(Fig. 3), which divisions are called the anterior and the posterior

parts or regions. As evidence for considering these two regions as

belonging to one structure, I offer the following considerations:

(1) The outside covering, the tunica propria, covers both regions

as a continuous structure.

(2) The inside lining is of the same structure and substance and

continuous; it is tripartite in both.

(3) The muscles and nuclei are arranged alike and have similar

histological elements in both regions.

(4) No valve exists between the anterior and posterior regions.

(5) There is a typical valve between the posterior margin of the

posterior portion and the intestine, just as found in all other nema-

todes studied for this particular structure.

(6) The dorsal gland is continuous in both regions.

The use of the expression “‘first and second esophagus” is mis-

leading and is on the whole unfortunate.

The anterior portion, to follow Cobb’s (1898) nomenclature, is

conoid in shape but expanding very gradually towards the posterior

portion, until it is about as thick as anteriorly; rounding off, it pre-

sents a nearly straight margin where the posterior portion begins

(Fig. 3). There is no evidence that esophageal torsion exists in this

species as in the case of A. duodenale.

This region is lined thruout with a substance similar in appearance

and staining reactions with the cuticula and it, like the latter, dis-

solves in alkalis; in these facts it offers some evidence for considering

it as being formed by the invagination of the external cuticula as

most authors have held. Owing to its size and position I have been

unable to obtain enough of it for an analysis. Its solubility in alkalis

and its failure to respond to a chitin test removes it from consideration

there, altho nearly all authors have called it a “‘chitinous lining.”

Anteriorly the lining is in the shape of a circular layer, and narrows

CAMALLANUS AMERICANUS NOV. SPEC. 91

down like a funnel, until a few micra posterior to its anterior opening,

which is within the field of the mouth apparatus ring, it changes into a

triradiate shape and encloses a very small cavity. This “funnel’’

(Looss 1905) is composed of a substance which is continuous with the

rest of the lining (Fig. 34), altho it appears set off from it, staining

very deeply and being much thicker. Anteriorly it abuts on the lower

margin of the jaws, as tho it was at one time continuous with them

also. This region of the lining seems to act as a cap for the anterior

portion of the esophagus as well as a lining. From here on the lining

is triradiate and six thickening appear, two on each third, and at the

center of each field. They are oblong in cross section, and are like

ridges extending almost the entire length of the anterior portion of the

esophagus. The lining is further thickened at the juncture of each

side, this acting as a hinge for opening and closing the lumen. These

thickings get larger posteriorly and just before the beginning of the

posterior region they become smaller, disappearing entirely 15 yu

anterior to this level; the triradiate lumen continues then to the pos-

terior margin of the esophagus (Figs. 41 to 45 give a series of views of

the lining, drawn on the same scale).

The marginal thickenings are for the insertions of the marginal

muscles (called so by Looss, 1905) as well as serving for a hinge, and

these muscles appear as a small group stretching out from this inner

insertion to the tunica propria. The nuclei of these cells lie in groups

of three at the same level and there are two such groups, so that six

nuclei are found in these muscles. The protoplasmic strands with

them are sarcoplasmic, and the nuclei lie half way between their two

insertions.

The other set of thickenings are for the insertion of the ordinary

muscles of the esophagus, which are more numerous than the mar-

ginal fibers and usually stain a little darker. Their nuclei appear

in groups of six at one level, two nuclei in each field; being three

groups, there are in all eighteen nuclei for these muscles. The

marginal and the ordinary muscle cell nuclei alternate with each

other thruout the entire esophagus. The latter nuclei lie a bit more

peripherally than the former, in most cases. The sarcoplasm of these

cells is more abundant than in the marginal muscle cells (see Figs.

30, 47, 49 for the structure of this region of the esophagus).

A gland lies in the dorsal third of the esophagus, which will be

discussed later.

92 T. B. MAGATH

The action of the esophageal muscle cells is obvious. Their

contraction opens the lumen and in living specimens this can be

seen, and that the entire lumen opens at once. The elasticity of the

lining closes the opening. The marginal muscle cells keep the lumen

in position and so have a kind of supportive function as well as helping

in the opening process.

The posterior region of the esophagus is made up of a different

looking tissue than that found in the anterior portion. The general

shape of this region, which is cylindrical, is shown ia Figure 18 where

it can be seen to be of nearly equal diameter thruout, being slightly

swollen in the anterior region and expanding up to its widest parts

from 2 aarrowed portion just behind the anterior enlargement.

The tunica propria of the anterior portion of the esophagus

extends over the posterior portion, somewhat invading the tissue

between the two regions, serving to set them off from each other

(Fig. 40). The lumen of the two regions, as has been remarked

before, is continuous, the characteristic lining of the anterior portion

giving way to a simple triparted lining with no special places for the

insertions of muscles in the posterior region. This lining extends to

the end of the valve.

Four different kinds of tissue can be recognized in this region

of the esophagus.

(1) The sarcoplasm of the dorsal esophageal gland, with its

single nucleus, will be treated under a separate division of the paper.

(2) The second tissue is of a nature not greatly unlike the muscle

cells of the anterior portion, and I consider it to be weakly devel-

oped muscles for the opening of the posterior lumen of the esophagus.

In this tissue can be seen small nuclei (Fig. 31), with a single nucleus

in each, near the lumen and therefore near the insertion of the muscle

fibers of the ordinary muscle cells; there are also marginal nuclei.

The arrangement of these nuclei follow the general rule of the anterior

portion. Just posterior to the anterior tissue cone (see below) there

is a set of three marginal muscle nuclei, further down there is a group

of six nuclei, two in each field; posterior to these appear another

group of three marginal nuclei and then the number and arrangement

is not, so far as I could find, constant in the individuals examined.

There are usually several (2 to 6) scattered nuclei, sometimes appar-

ently marginal and sometimes ordinary muscle nuclei; perhaps

CAMALLANUS AMERICANUS NOV. SPEC. 93

typically there is another group of six, following the general rule, but

have been overlooked for some reason.

The ordinary muscle cells are inserted in the middle of each side

of esophageal lining and have their outer insertions along the tunica

propria, spreading out more like a fan than do the cells of the anterior

region. The marginal muscle masses are, as in the anterior portion,

inserted at the angles of the lumen. While these two different kinds

of fibers are made out in the best preparations and by following thru

series of sections, specimens show some variation in the distinctness

of these two kinds of fibers, and more than that, there are often

insertions of muscles all along the lining of the lumen, with fibers

radiating out to the inner side of the tunica. The muscle fibers stain

deeply and show a fibrous structure with little or no granular material.

There are perhaps no more than twenty nuclei in this tissue.

(3) A third type of tissue is confined to a region in the anterior

region of this general part of the esophagus, and is in the shape of an

inverted cone (Figs. 40, 39). This tissue, a syncytium, is very granu-

lar and stains deeply, lies in the center of the esophagus around the

lumen and just posterior to the division between the two regions.

There are twelve nuclei within it, three in each of the three fields.

These nuclei are a little larger than the muscle nuclei, and each has

its nucleolus. There are numerous vacuoles in the esophagus sur-

rounding this plug of tissue and muscle fibers invade some of this

region. The function of this region is unknown and no suggestion so

far can be advanced until a further study is made of it.

(4) Concerning the last type of tissue I feel more certain. This

also is granular in nature and not very closely packed together, is made

up of larger granules than in the preceding case, but they stain very

lightly. This tissue fills up all the space not occupied by the others

so that there is considerably more of this type than all the rest put

together. One very interesting fact is its composition of but two

cells, their nuclei lying one in each of the two sub-dorsal fields of the

esophagus in their posterior tenths (Figs. 3, 33, 38). These nuclei

(Fig. 37) are spherical in shape with a spherical nucleolus in each.

The nucleoplasm is highly granular and the nuclei stand out sharply

as black staining bodies. This tissue, or rather these two cells, I

consider to be involved in the excretory function of this animal.

There is in the third division (dorsal) anterior to these two nuclei

94 T. B. MAGATH

which are on a level with each other, another large nucleus belonging

to the dorsal gland and by comparison with the other two seems to be

quite different not only in being smaller but also in being ellipsoidal.

In the table below the measurements of these nuclei are given.

Size Volume

Gland nucleus 0.0083 x 0.0140 mm. 0.000001182 cmm.

Excretory nucleus 0.0161 0.000002245

Gland nucleolus 0.0050 0.000000065

Excretory nucleolus 0.0061 0.000000108

The histology of this part of the esophagus and the small number

of nuclei, prevents it from being considered a gland, but rather favor

its being concerned with excretory process, especially when its rela-

tion to the rest of the excretory system is considered. Just how the

esophagus functions in this process is as yet unknown to me, but from

a theoretical standpoint it seems possible to imagine the excretory

products of the organs to be passed into the body fluid, and then taken

out from here by specific action of the two giant cells of the esophagus,

to’ be given up into the bridge and accessory tissue and finally into

the excretory ducts themselves. This would presuppose a discrim-

inating action on the part of the esophagus against the food materials

which must be present in the body fluid, but this assumption is not at

all unreasonable, since the same thing has been observed in the cells

of every plant and animal known. i

A rather interesting error is committed by Stephens (1916).

He writes: ‘‘In others (Cucullanus | now Camallanus], Ascaris, etc.),

a tube, the so-called glandular stomach, lined only by epithelial cells,

follows behind the muscular esophagus. This glandular stomach is,

from its structure, easily distinguished from the midgut, or chyle

intestine, which is like-wise cellular.’’ From the foregoing study it is

evident that for Camallanus, at least, this statement does not hold

true.

Like most, if not all nematodes, this species has a dorsal eso-

phageal gland, but glandular tissue is in no other field of the

esophagus. This gland extends from the very posterior margin of the

esophagus to within a few micra of the anterior margin of the anterior

region.

Anteriorly there is at its beginning an expansion of the glandular

tissue which includes most of the entire dorsal field and here a minute

CAMALLANUS AMERICANUS NOV. SPEC. 95

duct from this gland empties into the esophagus in the mid-dorsal

region (Fig. 30) between the two dorsal thickenings of the lumen;

this duct continues thruout the entire gland, lying in its central

region. Posteriorly the gland narrows, occupying an elongated

ovoid area in the mid-dorsal line. At the juncture of the two regions

of the esophagus the gland narrows greatly but expands in the

posterior region. Thruout this region the gland is larger than in the

anterior region and here and there can be seen little knob-like pro-

jections on either side, but these never extend beyond the area of the

dorsal third of the esophagus.

Very near the posterior end of the gland there is a large ellipsoidal

nucleus (Figs. 3, 37) with a single spherical nucleolus, their sizes

being respectively 0.0083x0.014 and 0.005 in diameter. In some cases

the gland seems to extend down into the dorsal member of the

esophageal valve.

The sarcoplasm of the gland is rather hard to analyze (Figs. 30,

31, 33, 38, 51). In sections stained with Mallory’s connective tissue

stain, the gland is colored red, due to the fuschin, while the rest of the

tissue in the esophagus is colored from a purple to a deep blue. The

gland stains with thionin, as also a little tissue within its immediate

neighborhood. In any good preparation of the gland can be seen a

structureless outer membrane and an inner granular portion. The

granules are large and relatively few, so that there are open spaces

within the gland, hence there must be a rather large amount of

hyaloplasm present. Around the nucleus the granules are more

numerous.

As to the function of the gland, if indeed it be a gland, I can offer

no suggestions other than those made by previous authors. These

particular worms being blood suckers, suggests an hemolytic or

anticoagulative function for this gland, yet the opening of the gland

duct is perhaps to far posterior to the mouth to favor this view. It

seems more logical to agree with those authors who think this struc-

ture is a digestive gland, altho the evidence is by no means plentiful

and referring to it as a “‘salivary gland”’ is certainly open to criticism.

In most nematodes studies there has been described some kind of

a valve between the esophagus and the intestine, and most authors

have called it the “‘esophageal valve.’’ On the contrary Looss

(1905, 1911) has claimed that this is really an ‘“‘intestinal valve” and

96 T. B. MAGATH

is here formed by a telescoping of parts in this region. Lane (1916)

states that this is true in the genus Ancylostoma. Looss has even

gone so far as to locate four cells in the anterior portion of the intestine

of the developing hookworm larvae which he claims give rise to these

valves, altho I can find no complete history of these cells given. He

(1905:91) bases his claim on the following statement: “‘The fact

that, in the valvular apparatus, as in the intestine which follows it,

only two cells appear in cross section, while, in the esophagus, three

cells are always found composing such a section, indicates that the

whole apparatus is to be regarded as a product of differentiation of

the intestine,’’ yet he admits a three-cell arrangement in the rectum.

However, he states else where that the inner lining of the valves is

continuous with the esophagus and thus “we see,”’ writes the author

(page 90), “‘that the outer tunica propria of the esophagus does not

unite with its inner lining but that there is a direct connection between

the tissue of the esophagus and the valves, the connection taking

place on their zmner edges.’’ Even his nuclear counts he admits were

made under difficulties and noted considerable variation in their

number and position.

In C. americanus there exists at the posterior margin of the

posterior part of the esophagus a structure which I wish to call the

“esophageal valve.”’ This structure is remarkably like that des-

cribed by Looss for A. duodenale. It is composed of three valvular

projections (Figs. 38, 36) which are well in the lumen of the intestine.

Each projection is composed of the muscular tissue of the esophagus

plus its own cell which is granular and stains lightly. Each third

possesses a nucleus of medium size which can be seen in good prepara-

tions. Around the three members of the valve there is a sphincter

muscle, containing one or two nuclei (Fig. 36). The cells of the

intestine come up around the valves covering the grooves round their

bases but do not cover their free margins; these project in the gut lumen.

The lining of these members is continuous with the esophageal lining

and they are somewhat set off by its invasion between the esophagus

and the valve, which is not so complete as to cut it off. Each pro-

jection represents the most posterior part of its respective third of

the esophagus.

Icansee no justification for assuming, in C. americanus at least, that

this valve is intestinal, and on the other hand very good ground for

CAMALLANUS AMERICANUS NOV. SPEC. 97

believing that it is an esophageal structure. In this I agree with

Cobb (1898), Quack (1913), Railliet and Henry (1915), Lane (1916a)

and others. The fact that the cells are continuous with the esophageal

syncytium, that they are lined with the continuous layer of the

esophagus, and covered with the same tunica propria, are three in

number and with a nucleus in each, that they are set off from the

intestine and of entirely different histological structure, and finally

that they function to prevent the backflow of food into the esophagus

points to their belonging to this organ rather than to the intestine.

Leuckart (1876) in his work on the life history of Camallanus

lacustris, figures a group of cells at the posterior region of the esopha-

gus which he found to develop into this valve like structure in that

species. This, of course is additional proof for considering this valve

of esophageal origin, for one would not expect the conditions to

differ in the same genus.

It is difficult to believe that this valve is not homologous with

that in Ancylostoma and the other nematodes, and yet if Looss be

correct, this could hardly be true. I have been unable to convince

myself either by a study of the text or his figures, that in the form

described by Looss, this valve is intestinal, and his failure to find the

third nucleus in the third valve member (he does not say in which

projection this was lacking, nor is he clear that it is always lacking in a

particular one) I consider due to his technique, and the condition

of the tissue at the time of killing and fixing. He admits his difficult-

ties in counting the nuclei in this region, which has been noted above

for the posterior region of the esophagus and these are often very near

the valve itself in contracted specimens, so that the chance for con-

fusion is greatly increased. After all, in C. americanus there may be

more than three nuclei concerned with this valve, but at least there

is one in each division. If Looss be correct in his statement that the

““two-cell”’? condition is carried in both the valve and the intestine,

on this reasoning one would expect many more nuclei than it would

be possible to have in the valves, because in C. americanus there are

many nuclei in cross section of the gut and in some forms, there would

be even more.

I am forced to the conclusion, therefore, that the valves of various

nematodes are homologous and are specializations of the posterior

portion of the esophagus; that the cells of the intestine have crept

98 T. B. MAGATH

up around their bases and a sphincter muscle has been developed

out of the intermediate edges of the tissue, perhaps in part from both,

or entirely from either one. This conclusion seems warranted from a

study of the present literature, although subsequent study may

show that there is here a fundamental distinction between certain

nematodes.

The intestine. The portion of the alimentary tract which lie

between the esophagus and the rectum is known as the intestine,

or chyle intestine, an unfortunate name, since there are no villi in

nematodes.

In Camallanus americanus this portion of the tract is made up of

tall, hexagonal, columnar epithelial cells. The inside of the gut is

not smooth in cross section, but is thrown into irregular low folds.

In some nematodes the inside of the gut is very smooth, in others

there are definite and very deep folds. In adults the cell walls usually

break down to some extent, so that often none can be seen, and with

this degeneration comes an apparent degeneration of the nuclei

(Ehrlich 1909). As in most nematodes, there are definite regions

in the cells. On the outside is a thick basal membrane and just inside

of this a slightly thickened portion or layer of sarcoplasm.

Towards the center of the cells are numerous reddish-brown

concretions or granules (Figs. 60, 115), about one micron in diameter,

more numerous in the older individuals than in the young, and

chiefly in the anterior part of the gut. Such concretions have attrac-

ted the attention of many students of other species and by nearly all

are thought to be excretory products of some nature (Exkretkérnen).

Looss (1905) describes them for A. duodenale, but here they are far

less numerous than in C. americanus, where they more often than

not almost fill the cells. Looss considered them as some product of

blood digestion, which seems very logical and would therefore repre-

sent what are sometimes termed ‘‘coffee-grounds’’ in human

pathology. These bodies are probably a part, at least, of the pig-

ment group of the turtle’s blood corpuscles.

In Ascaris this same kind of material has been noted and studied

to some extent by Flury (1912) and Fauré-Fremiet (1913). The

latter found them to be insoluble in the solvents of fats and resistant

to digestion with pepsin and trypsin. He expresses his belief in the

following words: ‘‘I] est donc tout a fait probable que ces grains

CAMALLANUS AMERICANUS NOV. SPEC. 99

sont l’expréssion ce la transformation d’une partie appréciable de

Vhemaglobine ingerée par |’Ascaris.”” I.am inclined to think that

they are not excreted in the form in which they appear in the gut

wall, because they have never been found free in the lumen, and they

accumulate with the increasing age of the worms, so that very often

they are nearly or totally lacking from the intestines of young animals.

However, this fact must be kept in mind; the body fluid is colored red,

and this color most likely comes from the blood of the host. It may

be that these pigment bodies represent stored up material in the walls

of the gut, and that they are intermediate products in metabolism;

they would then be changed into a fluid, giving the red color to it.

Thus some of the material might be used as food, or it may be that

parts are excreted, even before being used for food, passing out

through the excretory duct. (See the section on the body fluid for a

further discussion of this problem).

Among others who have noted the presence of non-cellular mater-

ials in the intestines of nematodes Cobb (1914) should be mentioned.

He called attention to ‘‘rhabditin” in the intestinal cells of Rhabditis

monhystera, and came to the conclusion, after his very brief study

of the material, that it was a carbohydrate, basing his conclusion on

the following results: slowly soluble in water, rapidly so in alkalis and

acids; insoluble in most organic solvents; the aqueous solution gives

no precipitate with barium salts; the substance does not stain with

iodin-potassium iodide solution, and the crushed bodies of the worms

gave a Fehling’s reduction; no trace of the substance remained when

the bodies were burned, a faint flicker over the sodium line of the

spectrum indicated to him the absence of the earthly constituents

that might be expected in certain excretory salts, such as calcium.

It is unfortunate that he saw fit to name this substance without more

knowledge of its nature. Of course his Fehling’s test was absurd,

since the bodies of nearly every animal will give a reduction with this

agent, especially nematodes, and he indicated no way whatsoever

of telling that these granules played a part in the reduction. The

failure to stain with iodine solution certainly excludes a great many

carbohydrates. It is impossible to tell just what he really had from

the very meager information given in his paper, and since he does not

refer to any special work on the subject one is inclined to think that

he did not consult these particular articles. One of the most recent

100 T. B. MAGATH

and thoro is that of Marie Quack (1913), who concludes that certain

granules, which agree in description very closely with ‘“rhabdtin”

and found in free-living and parasitic nematodes, are calcium salts,

and her evidence in very conclusive on that point. However, these

“Sphaerokristallen”’ are insoluble in water, alkalis and dilute acids.

Until Cobb publishes a more complete account of his work one is

forced to discount his conclusions, at least one cannot accept his

name without better justification from a chemical standpoint.

The nutritional zone (nutritorishe Zone) can be recognized as

the jayer of thickened protoplasm on the inner border of the cells

and inside of this another membrane. The ‘“‘Stabschensaume”’ is

very tall in this species, being nearly equal to the height of the cells

themselves. In young specimens, this layer shows very clearly

its arrangement. Each cell bears a definite clump of little bristles,

which proceed from each cell towards the lumen of the gut. In

the older individuals these bristles become matted together so

that the layer seems almost like a continuous one. Many authors

have called this a “‘chitinous layer,’”’ but this is not the nature of

the material of which it is composed for Quack has shown that it is

digested by the action of pepsin and is soluble in caustic alkalis.

The nuclei of the intestinal cells are ellipsoidal in shape, with a

single nucleolus in each, and lie either within the nutritional zone or

immediately below it. This position is unusual, for the intestinal

cell nuclei usually are said to be well in the middle of the cells, or

more typically near the outer margins. Supporting fibers can be

seen in the best preparations, stretching out from a slightly thickened

area around the nuclei.

Just anterior to the rectum the intestine shows a very poorly

developed valve (Figs. 116, 125, 126). The appearance is that

of certain cells being pushed up and in posteriorly, so that a small

pocket is formed and the lumen is made smaller. The nuclei are

very numerous in this region.

The rectum and cloaca. Between the posterior end of the intestine

and the anus there is a small region known, in nematode anatomy, as

the rectum. The region has excited the interest of workers in the

field, chiefly because of certain bodies which always seem to be

present, even in the most diverse forms. Various functions have

been ascribed to these organs, which are considered to be a group

CAMALLANUS AMERICANUS NOV. SPEC. 101

of three or four cells. Leuckart, Cobb and others have called them

‘anal glands,’’ but none have been able to propose a logical function

for glands in this region of the alimentary tract, since a secretion

poured out by them would pass into a cuticula-lined canal and right

at the opening of the tract to the exterior. In addition to this, the

demonstration of ducts from these cells is by no means certain.

Others have spoken of them as ‘‘giant cells” and ‘‘ganglion cells.”

Looss could not convince himself that these explanations would

explain the function of such cells and finally came to the conclusion

that they were cells which belonged to a syncytium of connective

tissue in the forms in which he studied the structure, and that ‘‘the

structure to which they are attached is a ligament for fastening the

chyle intestine to the rectum.”’ Before giving my interpretation

of the structure, it will be necessary to give in detail the condition

found in C. americanus. The modification in the males, due to its

entrance into the cloaca, makes it necessary to describe the condition

in the two sexes separately.

The female. In the females the rectum is a short tube 85 yu long

and greatly compressed dorso-ventrally. In the middle region it

assumes a Slightly triparted shape on the inside and towards the

end it shows several prominent excavations or indentations, the

largest of which occurs on the ventrum (Fig. 113). Other indenta-

tions are shown in Figure 128. Posteriorly the anus terminates the

rectum, and is in the shape of a slit (Figs. 113, 114). Where the anus

is located the ventral band is divided, its posterior two halves uniting.

The lining is rather thick and as a rule stains more deeply than the

cuticula, from which it is supposed to be derived and with which,

even in adults, it seems to be continuous, altho the division between

the two is usually well marked off. Anteriorly the lining ends abrupt-

ly, a few micra posterior to the regular cells of the intestine, and

between these two structures is a little space surrounded by three

cells, which lie immediately posterior to the lower margin of the

intestinal muscle cells.

These three cells (Figs. 8, 114, 127, 128) lie one dorsal and the

other two sub-dorsal; they are large and spherical in shape being

about 17 w in diameter. Each spreading out at its base, they form a

solid syncytium around the central cavity continuous with the lumen

of the gut. Anteriorly these cells pass into the fibrous tube which has

102 T. B. MAGATH

been mentioned previously, and thus they are connected with the

sphincter muscle; this fibrous material even extends back over the

cells, involving some of their inner and anterior margins. A large

spherical nucleus with a single nucleolus is found in each cell. Pos-

terior to these three cells are three others, nearly as large and whose

anterior parts push up under the anterior three larger cells, thus

replacing them. These cells are not globose but are flattened (Fig.

131), contain large nuclei and each is in one of the three fields as in the

case of the other cells. The last three extend almost down to the anus.

over the whole of the outer surface of the rectal lining, being rounded

out in their peripheral surfaces, they give the rectum the appearance

of a regular cylinder (Figs. 130, 131).

The male. In the males this region (Figs. 99, 100) of the gut is

essentially like that of the females but of course differs somewhat on

account of the modifications caused by the rectum opening into the

cloaca rather than at the anus, also on account of the presence in this

region of the termination of the male reproductive organs, which

become involved with the alimentary tract.

Here as in the case of the female there is a sphincter muscle

around the narrowed portion of the posterior end of the intestine

and extending just below it, the three giant cells. These cells are not

quite so large as in the case of the female and the two sub-dorsal ones

are pressed to an almost lateral position on account of the presence

of the genital duct lying along the ventrum of the gut. The cells

covering the rectum are also present, and these seem to be a part of

a syncytium covering the cloaca. The rectal lining is continuous with

that of the cloaca. The rectum itself is much shorter than in the

females, being only about half so long; it opens on the dorsal side

of the cloaca above the opening of the spicular canal.

The cloaca. In the male nematode the common cavity just before

the anus which receives the end of the gut and the reproductive

organs, is known as the cloaca. This very short passageway is a

cuticular lined cavity with an outer cellular covering, containing a

few nuclei and part of the syncytium covering the rectum. On the

dorsal side, as has been noted above, enters the rectum, and along

side of it (Fig. 92) on the ventrum, is found the terminal of the genital

duct. Just posterior to the opening of the alimentary canal is seen

the opening of the spicular canal. After a short course the cloaca

CAMALLANUS AMERICANUS NOV. SPEC. 103

opens to the exterior in the midventral line as the ano-genital aperture

(Fig. 79), 10 w in diameter and in a slightly elevated portion of the

cuticula, on either side of which are the two pairs of para-anal

papillae.

The interpretation of these structures in this case is not an easy

task and the final word cannot be said until the embryology is known.

I consider the posterior three cells described above to be the “ pos-

terior ring”’ cells of Looss, and think they are nothing more than the

rectal cells. They may even form the lining of the rectum, their

position and granulation would suggest this: at any rate they support

it and of course must help to connect up the posterior structures, but

I am unable to consider them as being separate parts of a special

ligament, as Looss would have one believe the corresponding structure

in the hookworm serves. The three anterior and larger cells, are

evidently the cells Looss thot made up the “anterior ring”’ and

these are near the region which is supposed to be contracted by the

sphincter muscle. Looss admits that there isa very close relationship

between the rectal sphincter muscle and the “‘anterior ring of the

rectal ligament,” and in reality the two structures seem to be one

and the same. The nuclei of the large cells are then in part nuclei

of the sphincter, and the globose portions of the cells are the sarco-

plasmic parts of the entire structure. The outer parts of the cells

are granular in character but the line around which the three cells

are united with each other is towards the anterior side, fibrous, and

continuous with and exactly like, the circular tube enclosing the

posterior portion of the intestine, and which is in reality the rectal

sphincter. A contraction of the basal ring of the three cell syncytium

serves to close the posterior end of the gut, helped by the action of the

tube of fibrous tissue. It is opened by the intestinal muscles, which

section see for details. In C. americanus the interesting bodies are

nothing more nor less than parts of the rectal sphincter. Under this

interpretation the two nuclei in the sphincter proper are not well

explained, unless they be considered as accessory in nature.

There is some doubt in considering these as purely connective

tissue cells as Looss thinks; they serve as such in a way, but the two

sets of three cells are better interpreted as separate structures and as

given above, at least in this species. From the text and figures of

Looss one cannot see that he has, in his own case, demonstrated his

104 T. B. MAGATH

contentions, for he clearly shows that the fibers of the sphincter

muscle are “‘intercalated’’ among the protoplasm of the three giant

cells.

Food. All of the evidence at hand points to the fact that the

normal food of this species is the blood of the host. This is indicated

by the red color of the body fluid and the pigment in the intestinal

walls.

Looss devoted some time to a study of the condition in A. duo-

denale and came to the conclusion that in this species the normal

food was not human blood but rather the intestinal mucosal cells.

This he demonstrated by the fact that the amounts of pigment

varied in different worms and not with their ages and in addition to

that, the pathological condition of the intestine of the host and the

presence of the intestinal cells in the lumen of the gut of the worms

bore out this conclusion.

In the case of C. americanus neither of these conditions exists.

I have never found host intestinal cells in the guts of these worms nor.

does the pathological picture in the intestine of the turtle indicate

that the intestinal lining was being eaten. The great amount of

pigment and the fact that it is found in greatest quantities in the older

individuals indicates further, that blood is the normal food of this

animal.

From an anatomical standpoint there is further evidence to this

effect. The presence of the small sharp hooks at the anterior end of

the jaws affords instruments for the laceration of the tissue and the

movements of the mouth apparatus are conducive of the same effect.

The strong suction made by the action of the muscles of the esophagus

serves to draw in blood. The blood corpuscles must be rapidly

digested for they are seldomly found within the parasite. All evi-

dence goes to demonstrate that these animals are blood suckers.

An interesting experiment was carried on to see if these worms

could be kept alive in a cultural medium and if they would use the

medium for food. After several trials a mixture of Witte’s peptone

and gelatin was obtained so that the warmth of the hand would melt

it and at room temperature (about 21 degrees C.) it remained solid.

Before the worms were introduced the medium was tested and gave

the following properties after sterilization:

(1) Tryptophane present in combination only.

CAMALLANUS AMERICANUS NOV. SPEC. 105

(2) Biuret reaction was positive.

(3) Clear solution, liquid at hand temperature.

(4) Micro Kjeldahl determinations gave the following results:

I. Total nitrogen per cc. 0.0039 gm.

II. Total nitrogen per cc. 0.0042 gm.

I. Non-protein nitrogen per cc. 0.0015 gm.

II. Non-protein nitrogen per cc. 0.0017 gm.

(The trichloracetic acid method was used)

Average total nitrogen per cc. 0.004 gm.

Average non-protein nitrogen per cc. 0.0016 gm.

Six worms were introduced into a flask of this fluid and incubated

at 25 degrees C. The worms were first washed thru a liter of steril

water in fifty different wash waters, using steril Stendor dishes, and a

sterile platinum needle to handle the worms. Every precaution to

avoid contamination was exercised. After allowing the worms to

remain for six days an examination of the medium was made and a

portion of it plated out in agar after twenty-four hours incubation

at the same temperature at which the worms were kept. In addition

to this a small portion was introduced into another flask of the same

medium and kept in the incubator for six days. The medium after

the action of the worms showed the following properties:

(1) Tryptophane as before.

(2) Biuret as before.

(3) Clear supernant liquid with a heavy precipitate, but the

liquid at temperatures below that of the room did not congeal.

(4) Nitrogen analyses:

I. Total nitrogen per cc. 0.0036 gm.

II. Total nitrogen per cc. 0.0042 gm.

I. Non-protein nitrogen per cc. 0.0033 gm.

II. Non-protein nitrogen per cc. 0.0030 gm.

Average total nitrogen per cc. 0.0039 gm.

Average non-protein nitrogen per cc. 0.0032 gm.

The worms remained alive in this medium for over two months.

The control inoculation was steril at the end of three days and

the inoculated medium gave the same results for total and non-

protein nitrogen as it did in the original case.

This demonstrated conclusively that these worms can live on

other materials perhaps only substances which are like those they get

from the blood. Just what they did to the medium was not learned,

106 T. B. MAGATH

but it is evident that they reduced the gelatin to non-protein nitrogen

how much further it went could not be investigated on account of

insufficient apparatus. This work will-form the nucleus of a sub-

sequent investigation to be undertaken by the author.

Worms were kept for two months on turtle blood agar, they being

transferred to fresh tubes when the contamination became great.

The maximum length of time they can be thus kept was not ascer-

tained in my experiments.

Bopy Cavity.

For a long time it has been shown that the body cavity of

nematodes was not empty but filled with ‘‘a fluid probably contain-

ing albumen, which curdles under the influence of acid and, when

poured into water becomes milky” (Looss 1905:67, translated from

Schneider). In the light of modern physiology it seems that the

statement of the early investigator of nematodes, Anton Schneider,

is by no means incorrect but has an element of suggestion which

is probably not far from the truth.

In the absence of a circulatory system and the presence of a large,

fluid-filled body cavity, which surrounds the organs, it seems logical

to suppose that this acts for the nematode muchas does the blood

system for other animals; the circulation of the fluid can be seen in

living specimens, due to the contortions of the body. If this be true

all intermediate metabolic processes and compounds will be found

here, and so the digested materials going from the intestine into the

organs, and the waste materials from the organs to the esophagus

and the excretory ducts will be found, as in other animals, within

the same limits and the selection out of the fluid will rest in the power

of discrimination of the individual cells.

If one cuts or injures the body wall of an individual of C. ameri-

canus there runs out of the lesion a quantity of reddish fluid, rather

thick and somewhat opaque, which seems to ‘“‘congeal”’ within a few

minutes. Alcohol and the usual killing and fixing fluids precipitate

it and thus it is preserved in sections of worms. Here the fluid

appears as a fine granular substance, staining with almost any stain

and partially or entirely filling up the space not occupied by the

internal organs.

Attempts to obtain hemin crystals from the fresh fluid have been

unsuccessful, but the fluid must contain some part at least of the

CAMALLANUS AMERICANUS NOV. SPEC. 107

pigment group of the blood of the host. There is something very

suggestive in the presence of the brownish-red granules in the intes-

tinal walls (see that section) and it seems that these granules are in

part responsible for the color in the body fluid. The fact that these

pigment masses accumulate with the age of the individual indicates

that their breaking down process is slow, hence they may be storage

products, and the fact that the worms loose their reddish color after

remaining for some time in water indicates to some extent that the

color of the body fluid comes directly thru the intestine into the body

cavity from the digested blood corpuscles, in this event part of the

color group would be retained by the gut in the form of the pigment

masses in its walls. The whole problem is an important and interest-

ing one and offers possibilities of solution which are more favorable

than many others within the same group of worms.

Flury and Fauré-Fremiet (1912) have studied the body fluid of

Ascaris and they have found the following substances within it:

water, sodium chloride, albumin, globulin, some pure bases, free

fatty acids, phosphorous compounds, cholesterol, some reducable

sugars and finally hemaglobin and often oxyhemaglobin.

Here and there appear in the body cavity, connected to various

organs and invading interstititial spaces, small strand-like materiajs,

which give one the impression of a loose connective tissue. This

material was called by K. C. Schneider (1902) ‘‘ Bindegewebe”’ and

by Looss “‘strand-like organs.’’ The former did not locate nuclei

within the mass, while the latter has reported finding them in two

places, and suggests an homology between these organs in A. duo-

denaie and the phagocytic organs or ‘‘biischelférmigen”’ organs of

other species. Goldschmidt (1906) has called this tissue ‘‘Isolations-

gewebe”’ and in the large ascarids has located a few cells in this

structure situated just posterior to the nerve ring. I have been

unable to find nuclei in this issue in C. americanus but this is not

surprising, since one would expect them to be very minute and might

easily be overlooked. No function nor homology can be proposed at

the present time for this structure in our species, and the literature

on the subject, tho large, is very much confused; that the whole

problem will have to be worked over carefully before a conclusion

can be reached is evident; the larger forms will have to be examined

first before the smaller ones are studied. I am under the impression

108 T. B. MAGATH

that authors have been dealing with the same structures here and that

it will prove to be nothing more nor less than a structure similar to

the mesentaries and supporting ligaments of other animals, for

holding in place the various internal organs. If this be true the name

proposed by Schneider is much better than that given by Gold-

schmidt. Looss’ name is at best a make-shift as would be any that

I could propose.

THE REPRODUCTIVE ORGANS

Female. The female reproductive organs (Textfig. G) are of espe-

Textfigure G. Diagram showing the general arrangement of the reproductive

system of the female. amt.u., anterior uterine branch; 0.d., oviduct; 0. v. ovary;

post. u., posterior uterine branch; s., sphincter; ér., trompe; v., vestibule.

CAMALLANUS AMERICANUS NOV. SPEC. 109

cial interest on account of the absence of the posterior ovary, altho

its uterine branch is found. This is all the more interesting because

in the Trichosyringata, an order not greatly removed from the

Camallanidae, there is only one ovary found.

On superficial examination one might be lead to think that the

posterior horn of the uterus was in reality a result of the mere mechan-

ical lengthening of a single uterus, due to the enormous number of

embryos developing within; but this is not the case, since in the very

young females in which the ovary has not yet begun to function, this

posterior branch is seen long before the female has been fertilized.

At this stage it is merely a posterior thread of cells leading from the

ovijector, corresponding to a similar anterior fundement. The details

will be found elsewhere in the paper.

In the anterior division of the reproductive organs can be found,

in general, the regions which have been found in most nematode

species. There is distinguished an ovary, oviduct, with a “‘recepta-

culum seminis,’”’ and anterior branch of the uterus.

The ovary is pyriform in shape, attenuated anteriorly and ending

in a rather long, slender cylindrical tube. Figure 66 shows the shape

and the fact that the tube is about half the total length of the ovary.

At the widest place the ovary is about 0.15 mm. The cylindrical

tube increases gradually from 10 uw to 20 win diameter. Within this

tube are recognized two areas as in the case of Ascaris and referred to

by K. C. Schneider as the “‘ Keimzone”’ and “‘ Wachstumszone,”’ each

composing about half the length of the tube. In the former zone

occurs an unorganized mass of primitive germ cells which begin in the

posterior part of this zone to arrange themselves around the inner

margin of the wall (Fig. 74). These cells are spherical in shape, 5 u

in diameter and with relatively large nuclei. Division of the cells

takes place within this zone for here mitotic figures can be seen.

By growth, these cells come to fill the cavity of the tube so that

only one layer around is seen and thus in the center they fuse (?) with

each other, their peripheral ends being free. So is formed the char-

acteristic structure found in most, if not all, nematodes (Fig. 73).

The ovogonia appear like the spokes of a wheel, fastened by their

fused ends, called a ‘‘rachis.”’ In this species there is but a single

rachis and about five or six ovogonia in each cross section. Under

the force of this mechanical pressure they are compelled to assume

110 T. B. MAGATH

a cone shape but still have relatively large nuclei. This zone extends

well down into the enlargement of the posterior region of the ovary

where the last zone begins, the so-called “‘ Reifungszone,”’ where the

cells begin to break away from the rachis and gradually assume a

spherical shape again. In this region the first polar body is begun

to be formed altho the process may be continued thruout the passage

of the eggs into the oviduct. On leaving the ovary the eggs are about

25 uw in diameter with very large neuclei and prominent nucleoli, one

in each nucleus.

There is nothing especially interesting about the histological

structure of the ovary. A rather thick deeply staining basal mem-

brane exists, and the wall is composed of a single layer of cells, very

much flattened out and like typical pavement epithelial cells, with

medium sized nuclei. As many as eight or ten cells can be seen in a

cross section. As the ovary lies in the body, it is more or less coiled,

but never more than twice, and these are very loose coils.

Posteriorly the ovary is rather sharply delimited by the

appearance of a second layer of cells on the outside of the epithelial

layer. These are cells with their inner sides muscular and a sarco-

plasmic portion towards the periphery, giving the oviduct an irregular

outline in cross section (Fig. 76). The nuclei of the muscle cells are

in the sarcoplasmic portion. This layer of cells furnishes the oviduct

with a circular layer of muscle and by peristaltic motion the eggs

are shoved along. Coincident with the appearance of the muscular

layer, the epithelial one becomes much higher so that the cells stick

out more all around the wall into the lumen and here and there very

large projections are seen, especially in one region, which I have

designated as the receptaculum seminis.

In fairly mature worms, three regions of the oviduct are dis-

tinquished (Fig. 66); the first, about one-third the total length of the

organ in 30 win diameter, then follows a second third, which suddenly

expands to a diameter of 130 » and contains shortly after copulation

a mass of spermatozoa; few are to be found elsewhere in the system.

Here the projections into the lumen (Figs. 75, 78) are very much lar-

ger than elsewhere, and groups of spermatozoa can be seen clinging

around such out-jutting pieces. Fertilization (Fig. 68) takes place

here or perhaps in the very anterior region of the uterus. Posteriorly

this receptaculum seminis reduces in diameter to about 17 » and the

CAMALLANUS AMERICANUS NOV. SPEC. 111

musculature becomes very much thinner, until it disappears at the

anterior margin of the uterus (Fig. 66). The epithelial cells remain

high thruout its entire course and no valves are encountered in this

region.

It is interesting to note in passing, that in cross section of the

receptaculum seminis the spermatozoa are cut transversely as well,

showing that their orientation is with the long axis of the uterus and

oviduct; they apparently progress up the entire length of the uterus

and posterior third of the oviduct, head first, maturing as they travel,

to waylay the egg cells as they pass thru the oviduct. The fluid of

the uterus and oviduct offer a medium for their progress.

Five worms were used for the compilation of the following table.

The reproductive organs were carefully dissected out and preserved,

stained and measured in xylol before they were sectioned. Unfor-

tunately the total length of the worms could not be gotten since the

dissections had to be made while the animals were still alive and they

were so active that it was impossible to ascertain their lengths at that

time.

A study of the sections showed that the shortest ovary and oviduct

belonged to the youngest worm, and that they then arranged them-

selves according to the table, with the fifth as the oldest female.

It becomes obvious that both the ovary and the oviduct grow with

the worm, but that there is a tendency for the ovary to outgrow the

oviduct, an altogether logical condition. Altho there are few cases

given here it is perhaps a fair sample since they were picked at random

from among a great many individuals.

III. OVARY AND OVIDUCT MEASUREMENTS

Organ a b c d e

OVA ere reas aS 1.9 2.0 2.4 3.2 3.5

OVIGUICEM eer ete sey MA 2.0 PAL 2.5 2G 2.7

PRO CARED PC een ner nance ON) 3.9 4.1 4.9 5.8 6.2

Ovary) OVIdUCtee se. 1:1.0 1:1.0 1:1.0 1:0.8 1:08

This uterus is simply a huge sac in which are contained the

developing eggs and embryos, for this species is viviparous. Its

walls consist of a single layer of pavement epithelial cells with fairly

large nuclei (Figs. 64, 71) and cell walls more or less indistinct, the

A? T. B. MAGATH

basal membrane which is present stains deeply. There are no muscu-

lar fibers in the walls of this uterus, altho Cobb as well as other

authors have described such in some nematodes. Looss failed to find

them in A. duodenale. Within the uterus is a fluid which has been

mentioned and this is precipitated by the killing and fixing fluids,

stains well and is undoubtedly nourishing for the growing embryos

(Fauré-Fremiet).

The anterior uterine branch is considered as beginning posteriorly

at the inner end of the ovijector and continuing to the beginning of

the oviduct (Fig. 65). The posterior branch ends blindly in a cul-

de-sac (Fig. 67), and takes its origin at the common juncture of the

two uterine branches and the vagina. Needless to say the uterus

grows, probably by stretching as it becomes filled with embryos.

In living animals the uterus passes to and fro (antero-posteriorly)

in the body cavity, undoubtedly due to the hydrostatic pressure

within the body and the uterus itself, for the uterus lies free in the

body, with no muscular fibers attached to it, being held somewhat in

place by the before mentioned strands of tissue.

Adopting the recent terms of Looss and Seurat (1912, 1914) for

the specific regions of the tube which leads out from the uterus to the

- genital aperture, I shall refer to this as the ovijector, for the sake of

simplicity (Fig. 62). Taking up its structure from within outwards,

it begins at the uterus as a tube 18 yu in diameter, posterior to the level

of the vulva, being then directed anteriad at a sharp angle and lying

at its origin on the ventral side of the body. Its course is by no

means straight and its length varies from 1.3mm. to 2.1mm. It

usually bends from side to side and in one female made a loose loop.

Its angle is rather sharp where it starts towards the vulva.

The ovijector is lined thruout its course, save for a short distance

at either end, with four rows of epithelial cells (Figs. 61, 72). These

cells are rather unique in shape, being more or less round as seen in

cross section and spindle-shape longitudinally (Figs. 21, 59). Their

nuclei are in about the same level, so that in a given transverse section

one sees four nuclei. These cells do not fill the entire cavity and a

space extends between the four rows. The cells are 42 4 long. At

the inner end of the ovijector the rows become a little irregular and

not well marked out because of the appearance of more cells, so that

it passes into the uterus without a valve and presenting no radical

CAMALLANUS AMERICANUS NOV. SPEC. 113

histological difference. The covering of the tube is composed of a very

heavy layer of circular muscles, which is anteriorly 10 wu thick and

gradually dimishes in thickness until none can be seen at the exact

juncture with the uterus. Many nuclei occur within this layer and

the muscles obviously act as do those of the oviduct; by peristaltic

motion they help to pass the embryos to the genital opening.

From a region just where the ovijector begins to turn towards

the ventral side to its openings, this tube has a cuticular lining, which

seems to be continuous with the external cuticula (Fig. 63). During

the short distance in which the sphincter lies in the body cavity,

there is around the cuticular lining a very heavy layer of circular

fibers (Figs. 58, 62), with many nuclei, and which clearly function as

a sphincter, their sarcoplasmic portions being towards the periphery.

Sometimes the cuticular lining extends posteriorly over the four rows

of cells, but then only for a short distance, and these cells do not

appear very far forward of the end of the cuticular lining.

Thus the ovijector extends anteriorly past the level of the genital

opening and suddenly makes a very sharp turn within the anterior

vulvar lip, loses its musculature and passes posteriorly to open near

the mid-ventral line of the body, but in the side of the vulvar lip

towards the tail. This final tube (Fig. 63) is the ‘‘vestibule” of

Seurat and is only a few micra in diameter and will allow of the

passage of only one embryo at a time.

Just at the highest point of the turn a very interesting cuticular

structure is present, which from its position and structure is consid-

ered as a valve, opening by its own elasticity and closed by the action

of the sphincter (Figs. 58, 60). This valve is nothing more nor less

than two, somewhat spherical, masses of material, apparently derived

from and attached to the inner lining as tho they were mere thicken-

ing in its wall, and occupying a right and left position. Compression

by the sphincter would push these two bodies together and thus close

the passage way. There is the further possibility that they serve in

some way during the act of copulation, e.g., in holding the spiculum

within the vulva.

The vulva is very conspicuous in this species and is provided on

both sides with a very prominent lip, of which the anterior one is the

greater developed (Figs. 5, 58, 63). The posterior lip increases as

the worms grow older so that in females just before giving birth

114 T. B. MAGATH

to embryos this lip is rather large and becomes pushed out to one

side or the other by the overhanging anterior projection.

The anterior lip is about 0.3 mm. long and juts out about 0.12 mm.

ventrally from the body; the shape is difficult to describe but can be

easily seen in the figures as a swelled out portion of the ventral wall,

overhanging its own posterior limit on the body wall.

In sections of the vulva one can see that the ventral band spreads

out over the inner margin of the cuticula, and is very much thickened

in the whole general region (Fig. 62); it becomes divided around the

actual opening of the vestibule, which seems to pierce it, then unites

below the opening to continue posteriorly as a single line or band.

The cuticula is transversely ridged on the inner side so that it

presents eleven definite places for muscle insertion (Figs. 5, 63).

Special muscles exist in this region, there being twelve large cells,

each with a nucleus and having its greater insertion on the cuticula,

then converging, they find their second insertion around the end of

the sphincter and vestibule. Thus one sees in longitudinal sections

a radiating structure of muscle cells in this region.

Contraction of these muscles will pull up the lower overlapping

portion of the vulvar projection and at the same time turn the

opening away from the body wall, while the elasticity of the wall

itself will tend to restore it to its original position, aided by the

contraction of the muscles in the lower portion of the vulva. These

muscles are evidently modified somatic muscle cells. Their function,

while possibly related to the expulsion of the embryos, is most likely

involved in the act of copulation as well.

Larvae. It does not lie within the scope of this paper to discuss

in detail the larval stage of this parasite, however, a few words will

not be amiss. The larvae appear within the uterus of the female in

two conditions, but in the first stage only. The two conditions

referred to are (a) a phase in which the first cuticula is closely

applied to the body and is the youngest phase, and (b) a phase in

which the first skin is loose and the larvae are contained within it.

When the larvae are freed from the female they are very active and

the first skin is shed within a few hours, they then being in the second

stage.

In the uterus these larvae are at times very active and can be

stained in vitro with methylene blue. Those in the first phase stain

CAMALLANUS AMERICANUS NOV. SPEC. 15

readily but those with the two skins do not stain until after several

hours. They range in length from 200 yu to about 360 yu, and occasion-

ally they are found as long as 540 yw, but this is unusual. Several

regions can be located, in particular an anterior region, which has a

great many nuclei and is about one-third the total length of the body.

This is evidently the start of the esophagus. A light staining area

passes around this regions and is interpreted as being the beginning

of the nerve ring.

In cross section the larvae are seen to be made up of a tube of

cells, about nine appearing in such a section (Figs. 121, 122). The

anterior end is bluntly rounded off, while the posterior tip is sharply

pointed (Fig. 10). Even in young individuals there are four nuclei

in the anterior tip (Fig. 11) which stain deeply and are more distinct

than any others in that region. Perhaps they are the foundation of

the complicated subcuticular head structure and will form the oral

apparatus. On the whole the nuclei of the body are very numerous.

and occasionally one or two can be seen inside the tube of cells of

which the worms are composed.

Some attempts have been made to find the life history of this

species, but so far they have led to negative results. The larvae will

live in water for several weeks, but they grow little and do not moult

after the first skin has been cast, so far as was learned. These young

stages are not as a rule in the intestine of the host. Every thing

points to the necessity of an intermediate host in this parasite as in the

case of Camallanus lacustris.

Male. The reproductive organs in the male nematodes are

characterized by their simplicity and in this respect C. americanus

does not differ from the general type, altho some peculiarities exist.

There are three regions in the reproductive organs proper (Textfig.

H), all within a single tube on the ventral side of the body, which may

be displaced to the right or left, or parts of the tube may occur on

the dorsal side in old animals where the tube has become long and

sinuous.

The anterior region is known as the testis. This varies in length

in different individuals according to their ages. In the young it is

almost straight, in older forms it may have several bends, a loop, or

may turn back on itself in the esophageal region and grow posteriorly

almost to the anus. This tube is at its extremity 10 w in diameter

116 T. B. MAGATH

and, after about 130 yw, has usually a small enlargement about

20 » x 30 uw (Fig. 101). Then the tube very gradually enlarges up to a

diameter of 35 yu, passing without much differentiation into the

seminal vesicle, which, at its anterior end is about 65 uw enlarging up

to 130 u at its widest place in the posterior region. This part of the

-de

Textfigure H. Diagram showing the general arrangement of the reproductive

system of the male. de., ductus ejaculatorius; s.v., seminal vesicle; ¢., testis.

system is about 3.3 mm. long. It passes into a small short tube and

then into a region known as the ductus ejaculatorius continuing to

the cloaca into which it empties on the ventral side (Fig. 92). This

latter organ is about 2.2 mm. long and has an anterior diameter of

66 uw, narrowing to 20 uw just before the cloaca and to about 10 u at its

entrance into the common posterior ending of the genital and ali-

mentary ducts.

CAMALLANUS AMERICANUS NOV. SPEC. V7

In toto mounts these regions are well marked by their differences

in staining. Of the three, the last region stains the deepest, the testis

next and the seminal vesicle very lightly.

The spicula should be mentioned here as being accessory genital

organs.

There is nothing especially interesting about the testis which has

not been previously considered by zoologists. It consists of a tube,

made up of a single row of cells with small nuclei, rather hard to find

and comparatively few in number. The cells are very much flattened

out and have a rather heavy outer basal membrane (Fig. 83). In

the very anterior end of the testis, which ends blindly, are found the

primordial germ cells and these can be seen, as in the case of the ovary,

as very small cells which divide rapidly, as seen by the frequent

mitotic figures. Further down in the testis the rachis formation is

noted.

The seminal vesicle is but an enlarged portion of the system and

contains in mature forms a great mass of germinal cells, before

copulation has taken place. The cells here are free from the rachis.

The walls of this region (Figs. 80, 104) are in direct continuation with

those of the testis and but for an external constriction there is not a

sharp delimiting area. The cells are more spread out here so that they

become very narrow and with small nuclei. The size of this region

is determined chiefly by the amount of germinal products present.

These products are considered by most authors as still being

immature until after they have been for sometime in the uterus of

the female. Looss, however, speaks of ‘‘mature spermatozoa”’ in

this region of the system in A. duodenale and refers to a ‘‘mantle”’

surrounding nematode spermatozoa (1905:111). Concepts differ

from other evidence and I am at a loss to explain his observations.

The passage of the seminal vesicle into the last region of the system

is indicated by the appearance of high epithelial cells and an outer

muscular layer. The epithelial cells crowd in at the anterior end and

thus form a kind of valve (Fig. 112).

The ductus ejaculatorius of the male reproductive system (Figs.

81, 97) is composed of two layers, the outer of which, consists of a

circular musculature containing a very few nuclei, which appear

in the sarcoplasmic part, and project out a little on either side of

118 T. B. MAGATH

the tube. This muscle layer is thin and must act as a muscle to

produce peristaltic motion, functioning in the removal of the spermatic

fluid from the male generative organs.

The inner layer of this tube is cellular and composed of rather tall

columnar epithelial cells, about twelve being seen in a transverse

section. These cells are extremely granular and have moderately

sized nuclei. Figure 81 shows a cross section of this organ. Repro-

ductive cells are sometimes seen in this region but when crowded

down by the formation of the products in the tube above, and hence

only in the older specimens.

For the function of the epithelial cells I can offer but one sugges-

tion, they may secrete, at the time of copulation, a fluid, perhaps

gelatinous, which accompanies the sperm into the uterus of the

female. This fluid may be nutritive or may be merely a mechanical

carrier for the cells. I have sought in vain for information which

would lead me to believe that this organ secretes a cement to stick the

male to the female during copulation. The fact that the male cells

are not generally retained in the ductus ejaculatorius for a very long

time, presents some difficulty for considering it as secreting a nutri-

tive fluid, yet after they have gotten into the uterus of the female

there is yet necessity for some nutrition of the developing spermatids.

It would seem as tho some fluid medium was necessary for conveying

the male cells into the female and it seems most logical to believe that

this organ secretes such a fluid.

The statements of Looss concerning this organ in the hookworm

are not easily followed for he has included the description of the

cement glands in the same chapter, but one is led to believe that

he did not see a muscular layer around the organ; such a layer

certainly exists in our species and has been noted in many other forms

as well.

A further word concerning the spermatic cells. They reach matur-

ity in the seminal recepticle of the female and there as has already

been noted they may be seen oriented with their long axis parallel

with that of the uterus and oviduct. They apparently have, their

“heads” pointing anteriorly. Their shape is of interest; they are

elongated and about 16 uw; have a short pointed tail and three more or

less deeply staining areas, about equal in size and bulging out some-

what (Fig. 82). They are 3 » wide in the widest place.

CAMALLANUS AMERICANUS NOV. SPEC. 119

The spicula present a rather characteristic appearance in this

species. The right one (Fig. 94) is by far larger than the left and

differs in some other respects. The smaller (Fig. 95) of the two is but

slightly curved and has no embellishments of any nature, being slend-

er, acuminous in form and tapering from a diameter of 8 toa very fine

point. Its total length is about 310 yu in all specimens, and ends

anteriorly in an acute angle.

The right spicula is 18 » in diameter anteriorly and it also has an

acute angular anterior ending, so that a cross section near its anter-

ior end shows only a crescent-shaped structure (Fig. 90). This

speculum is about 870 uw long and is also acuminate in form. It is

slightly curved and 75 pw from its tapering point has on its dorsal side

a small point (Fig. 93) projecting dorsad and 5 yu long, curving slightly

anteriad. Posterior to this point the spiculum dips sharply ventrad

and then rapidly tapers to a fine point.

The structure of the spicula is very interestin and has been given

in detail by Looss with whom I agree in the fundamental points.

They consist of tubes (Fig. 88) of cuticular material, which dissolve

in concentrated alkalis and stain deeply with almost all stains. The

shell of the right spiculum is 4 » thick and about eight times as thick

as the smaller one (Fig. 89). Near their posterior tips they become

solid. The cavity is filled with a very granular “‘pulp”’ which contains

nuclei at the anterior end only. Sections show that this pulp is

continuous with the outer covering of the spiculum (Figs. 90, 103),

which is called the “‘spicular sheath”? or the musculi exsertores

spiculorum. In this mass of tissue which appears just at the head of

each spiculum are from three to five small nuclei, evidently the nuclei

of this tissue, although others will be mentioned later.

The extensor muscles are essentially alike those described for

other species. In C. americanus this muscle (Fig. 96) is about 5 yu

thick in the case of the large spiculum and 2 yw in the smaller, the

thickness varying a little with the degree of contraction of the muscle.

It seems to present two distinct layers of which the outer is a little

wider and more granular, corresponding to a sarcoplasmic layer, and

in this layer from time to time are noted large spherical nuclei (Fig.

103), especially near the posterior end of the organ. The inner layer

is differentiated into fibers and is evidently the contractile layer of

the muscles. Because of its intimate connection with the heads of the

120 T. B. MAGATH

spicula and its lack of attachment along their courses, its acts like a

spring to shoot the spicula out when they are to be protruded. For

this purpose they have been anchored firmly at their posterior ends

and this is provided for by the places of insertion (Fig. 103) on the

dorsal wall of the cloaca in a manner to be described a little later.

Other muscles have yet to be mentioned in connection with the

spicular apparatus; these are the musculi retractores. They are

seen in single masses of fibrous tissue attached to the heads of each

spiculum (Fig. 103) and extending for a short distance underneath

the spicular sheath. On the oblique side of the anterior end of the

spiculum this mass sends out several small branches which become

attached to the spiculum and somewhat embedded in its pulp (Fig.

86). In each case the single mass divides a short distance anteriorly

into two long slender muscles, which proceed, two on either side of

the body, free in the body cavity, (Fig. 97) for a distance of about

one-fourth the total length of the body to their respective anterior

insertions. Each muscle has about half way in its course a small

amount of sarcoplasm surrounding a nucleus (Fig. 105). The muscles

of the left spiculum are correspondingly smaller than those of the

right and are not quite so long. After the muscles have divided,

they pass anteriorly, each member of a pair running close together

and become inserted at each of the four sides of the lateral lines.

The spicular canal (Fig. 100) has been discussed at length by Looss

and to his account I have little toadd. The structure has been called

by some authors the “spicular sheath”? but as Looss clearly points

out, it is a separate structure, and should therefore be given another

name.

The canal appears on the dorsal side of the cloaca where two very

small cuticular wings arise on either side of a small groove, which has

a cuticular lining. The lining is covered with a granular layer of

protoplasm which contains a few nuclei, three according to Looss.

This single canal continues anteriorly at a sharp angle from the cloaca

and shortly divides into two grooves into which the spicula project,

their sheaths being firmly inserted on this structure; the cuticular

lined canals continue but a short distance anteriorly.

THE NERVOUS SYSTEM.

Comparatively few points are known and understood concern-

ing the morphology of the nervous system of the nematodes as a

CAMALLANUS AMERICANUS NOV. SPEC. 127

whole. The enormous mass of literature that has accumulated on

the subject has concerned itself with the nervous system of Ascaris

megalocephala and A. lumbricoides and while it has contributed to

the morphology of these systems, it has chiefly been concerned

with the various problems in the neurone theory, cell constancy,

etc., offering considerable information on these subjects. In

addition to this, these workers (Apathy 1908; Goldschmidt 1907,

1908, 1908a, 1909, 1910; Deineka 1908, 1912) have investigated the

members of the genus Ascaris admittedly the highest specialized of

the group, and many conditions are found in this genus and in

particular these two species which appear in other nematodes in a

much simpler and more elementary stage or are totally lacking.

It does not lie within the field of the present paper to consider

these problems and no attempt has been made to present a review of

the literature which has been so well done by de Rouville (1910, 1911).

The work of Looss (1905), because of its strictly morphological

character, will demand consideration and since it is really the only

piece of work that is at all complete, reference will constantly be

made to it.

One is struck in looking over this work with the apparent ease

with which Looss was able to trace out the minute fibers and locate

the most delicate connections and for all of this he gives no special

technique; one must conclude that he did the work on material pre-

served in glycerol-alcohol and handled according to his method

which is at best poor for working out the finer details. One cannot

help but marvel when he reads of nerves which ‘‘are small and may

consist at most of two or three fibers,’ or “the first fiber which leaves

the ganglion,” etc. Every method known has been tried to demon-

strate the nervous system in C. americanus and it is only after many

trials and piecing out gaps in each method that the conclusions about

to be set forth have been obtained, which I regret to say are all too

fragmentary and liable to error. If the finer connections, comparable

to those described by Looss in A. duodenale really exist in my species,

I have failed to locate them and have difficulty in believing that they

are present in one species and not in the other, altho one is not

surprised at even greater differences between C. americanus and the

genus Ascaris. In one or two of the major connections are to be noted

differences in my species and Looss’ description.

122 T. B. MAGATH

Like most nematodes, there exists in this species a nerve ring,

better referred to as the cephalic commissure, There are associated

with this commissure twenty cells in each lateral half, in all forty

cells, of which some may be adventitious, and the greater number

are just anterior to the nerve ring. The rest are just below it, altho

some are scattered in the subcuticula surrounding the esophagus.

Some of these cells anterior to the nerve ring are found in groups in

definite places. From these groups six nerves pass anteriad, while

two are laterals, two sub-dorsals and two sub-laterals. (See Textfig.

I for diagram of the nervous system). A further word will dispose of

Textfigure I. Diagram of the cephalic part of the nervous system. ant.l.,

d.c.g., dorsal cervical ganglion; /.c.g., lateral cephalic ganglion; sub.J., anterior sub-

lateral nerve; swp.l., anterior supra-lateral nerve; v.c.g., ventral cervical ganglion,

n.1., nerve ring; p.v.c.g.,postventral cephalic ganglion.

these nerves; they supply the region anterior to the nerve ring, and

each runs forward very close to the esophagus and supported by

surrounding subcuticula. The two sub-ventrals have within their

course near the anterior tip one nerve cell in each (Fig. 14), and

these give out branches to supply the adjacent tissue. Nerves in

Ascaris and Ancylostoma are found passing anteriorly also, but these

go to papillae, none of which exist in C. americanus so that I refrain

from homologizing these structures until more is known about them.

Under the present condition I believe that the nomenclature for these

nerves should be based upon their position alone.

Below the nerve ring one can recognize five ganglia which are

called the dorsal cephalic ganglion, the ventral cephalic ganglion,

the post-ventral ganglion and the two lateral ganglia. Commissures

CAMALLANUS AMERICANUS NOV. SPEC. 123

connect the latter two with the nerve ring on the one hand and the

ventral cephalic ganglion on the other. Longitudinal nerves arise

from each ganglion.

As has been clearly pointed out by previous authors, the cephalic

commissure, or nerve ring, is composed essentially of fibers which

originate from the ganglia, hence this structure is not regarded as

the fundamental part of the nervous system. In C. americanus the

nerve ring (Figs. 3, 34, 52) is in direct contact with the esophagus all

the way round and is contributed to by tissue from all four longitu-

dinal lines, altho Looss maintains that the dorsal one plays no part in

this formation in the hookworm. The fibers themselves are chiefly, if

not entirely, from the ventral and lateral cephalic ganglia. The nerve

ring is slightly oval in cross section and about 10 uw in diameter. The

fibers are supported by loose tissue network of subcuticula origin.

The dorsal cephalic ganglion is the smallest of the anterior gang-

lia (Fig. 54) and is situated on the inner side of the dorsal longitudinal

band just beneath the nerve ring. It consists of but three small

cells which give rise to the dorsal nerve, which in turn continues

posteriorly in the dorsal line.

The ventral cephalic ganglion is horse-shoe-shaped (Figs. 52, 54)

and lies at a little more posterior level than the dorsal cephalic gang-

lion. From it pass two large masses of fibers to the nerve ring (Fig.

53), and posteriorly the collected fibers from the ganglion pass

towards the tail in the ventral line. This ganglion consists of about

twentyefive cells of varying sizes, each having a relatively large

nucleus with a single nucleolus. Further, from this ganglion pass a

right and a left commissure in the subcuticula to reach the two lateral

cephalic ganglia.

The post-ventral cephalic ganglion appears a short distance

posterior to the ventral cephalic ganglion and in the course of the

ventral nerve (Fig. 55). Asa matter of fact it appears at the opening

of the excretory duct, lying immediately above it, and is composed

of three or four small cells. Goldschmidt has described a similar

ganglion within the course of the ventral nerve in Ascaris and these

two are probably homologus.

The lateral cephalic ganglia (Figs. 35, 54) are by far the largest of

the ganglia and are directly connected to the nerve ring, altho Looss

failed to find such connections in A. duodenale. These ganglia begin

124 T. B. MAGATH

on about the level of the ring and gradually increase in size, occupying

the inner margins of the lateral lines, even dipping in between their

two halves. Posteriorly, they diminish in size until a few cells string

out nearly to the level of the cervical papillae. The commissure to

the ventral cephalic ganglion has already been mentioned. A nerve

goes from each ganglion to the cephalic papillae on the same side and

posteriorly the lateral nerves arise. I can be certain of only one on

each side, and these continue caudad in the lateral lines, in the anter-

ior region of the body, near the cuticula and in the mid-lateral line.

There are about thirty cells in each ganglion.

At the hands of both Apathy and Goldschmidt, the minute struc-

ture of the ganglionic cells in Ascaris have received special attention,

and these authors have offered many interesting considerations, most

of which involve physiological inferences and explanations which

lie outside the present work. In brief, Goldschmidt has found that

typically three zones exist in the ganglionic cells, an outer, middle

and inner. The outer zone is made up of a rather coarse alveolar

structure and borders the cell. The middle layer has smaller alveoli

and is continuous with the nerve process. The inner zone, also alveo-

lar in structure, lies immediately around the nucleus. Various

modifications occur in the various cells of the ganglia so that in most

of the bipolar cells one fails to recognize separate zones. Further-

more, one often notes that the borders of the alveoli are so arranged

as to give the cell the appearance of being made up of radiating

structures, and again this latter type of cell may be further modified

to present a “‘central body” around the nucleus, which is continuous

with the neurofibrills. Fibroid substance is present in varying

amounts in all the cells.

While so complete a study of the histology of the nerve cells in

C. americanus has not been made as Goldschmidt has done in the case

of Ascaris, I have nevertheless satisfied myself that the conditions

here, while essentially like those in this genus are not so complicated.

These cells are small, the largest having a short axis of about 30 u

and the structure is therefore hard to make out. In only a few

instances could neurofibrills be recognized, but in good preparations

one can see and follow for some distance the nerve processes of the

cells. Figures 106 to 109 show several cells drawn from one of the

lateral ganglia. In none of these cells have I been able to recognize

CAMALLANUS AMERICANUS NOV.:SPEC. 125

three distinct zones altho there is usually a thickened area around

the nucleus. Figure 108 shows a central body and distinctly radiating

protoplasm and the nerve fiber continuous with the central body,

exactly as Goldschmidt has figured it for Ascaris. The other cells

show beautiful alveolar structure but zones are not marked off. In

the bipolar cells the alveoli are very small.

Within the cephalic ganglia has been noted only two types of

cells, agreeing with Goldschmidt’s unipolar and bipolar types. Per-

haps multipolar cells exist also, but these have not been seen.

The longitudinal nerves are extremely difficult to trace thruout

their courses and I cannot give a positive statement of their behavior

except in certain regions. The dorsal nerve continues to the tail

in the dorsal longitudinal line, supplies the somatic muscles with

nerves and diminishes to an uneventful ending near the posterior end

of the body.

The ventral nerve is the largest of all and can be found in the

ventral line (Figs. 53, 119). This nerve also supplies the muscles of

the body and in the posterior region enlarges greatly. Its ultimate

fate will be considered in a special section.

I am not at all sure of the lateral longitudinal nerves, they are

small and arise at the base of the lateral cephalic ganglia. Each gives

a branch to its corresponding cervical papilla (Fig. 111) and continues

posteriorly in the lateral lines. One cannot say whether these nerves

are doubled or single thruout their courses. They become involved

in the complicated structure of the caudal end of the body, which

is so different in the two sexes as to demand separate consideration.

In the female as the ventral and lateral nerves approach the tail

they become much thicker and here there is only one lateral nerve in

each lateral line, carried near the excretory canal and taking its

place in position when the excretory canal ends. (See textfigure J).

Textfigure J. Diagram of the caudal part of the nervous system of the female

a.g., anal ganglion; a.l.c., anolumbar commissure; @.r.c., anorectal commissure; l.g,

lumbar ganglion; /.7., lateral nerve; r.g., rectal ganglion; v.n., ventral nerve.

126 T. B. MAGATH

Just anterior to the anus a ganglion appears in the ventral nerve

and contains from four to five cells (Fig. 130). A relatively large

commissure passes on either side from this, the anal ganglion, around

the rectum to join with the rectal ganglion which lies on the dorsal

side of the rectum a little anterior to the anal ganglion. This rectal

ganglion has only three cells in it, a large medin one and two smaller

laterals.

There are right and left ganglia in each lateral nerve called the

lumbar ganglia, each consisting of five or six cells and these lie a little

posteriorly to the level of the anus on the inside margins of the lateral

lines. A small commissure connects the lumbar with the anal gang-

lion. Nerves continue into the tail from each lumbar ganglion and

two small nerves pass posteriorly from the ana] ganglion, one on

either side of the anus.

It will be noted that the caudal nervous system of the male very

closely corresponds to the condition in A. duodenale, the most impor-

tant difference, which is of no consequence, being that in the hook-

worm there is a paired anal ganglion; in this respect it differs from the

condition found in Ascaris and C. americanus (Textfig. K). The

Textfigure K. Diagram of the caudal part of the nervous system of the male.

a.g., anal ganglion; c.g., cloacal ganglion; /.g., lumbar ganglion; /.”., lateral nerve;

r.g., rectal ganglion; sr.g., sub-rectal gland; v.n., ventral nerve.

same statement might hold true in the case of the female as well.

One other difference will be pointed out later on as regards the males.

While differences occur in the two sexes in respect to the nervous

system in the caudal region of the body, they can still be homologized

in most instances, if not entirely.

CAMALLANUS AMERICANUS NOV. SPEC. 127

The ventral nerve becomes very much enlarged at the beginning

of the region of differentiation in the caudal end of the body of the

somatic muscles (Fig. 87) and here and there, branches from these

caudal muscles bend over to the ventral nerve for their innervation.

Just anterior to the ano-genital aperture there is found the anal gang-

lion (Fig. 92). In the males as in the females this ganglion is not

paired, but in the former it is very much larger, for it contains about

twice as many nuclei. From this ganglion I have been unable to

trace nerves but two commissures were found. These arise very

close together and pass dorsally (Fig. 99) and at the same time

anteriorly, one of them assuming a more anterior position than the

other. This one goes to the rectal ganglion (Fig. 98) which lies on

the dorsal side of the rectum in the same relative position as the rectal

ganglion in the female.

As in A. duodenale this ganglion seems to have been divided for

another small one is found posterior to it and between the spicular

canal and the rectum (Fig. 98). To this ganglion, the sub-rectal, the

second commissure from the anal ganglion passes. In its course are

found ganglia lying on either side of the cloaca, for this commissure

passes obliquely around the cloaca, and since corresponding cells

in A. duodenale have been called by Looss, the cloacal ganglia, the

name for the structure here described will be retained.

In the lateral lines, beginning a little above the anus are found

ganglionic cells in the course of the lateral nerves. At first these are

but a few cells, but on passing backwards, the number of cells in each

lateral line becomes greatly increased (Fig. 84), until below the anus

there is a considerable mass of ganglionic cells, which continue almost

to the tip of the tail. Nerves from these ganglia supply the ribs of the

caudal region of the male. I have tried to find one or more commis-

sures to the anal ganglion, for they surely must exist, but so far the

attempt has been unsuccessful, for the region is very hard to study on

account of the condition of the tail in preserved specimens, it usually

rolls in such a manner as to preclude the possibility of getting good

sections.

Looss has noted in A. duodenale three pairs of lateral ganglia in

this region and he has termed them beginning anteriorly, the lumbar,

postlumbar and costal ganglia, but since in C. americanus there is no

definite division of the ganglia, I propose to call this pair in this

128 T. B. MAGATH

species, the lumbar ganglia, believing them to be homologus with

those in the female and possibly with all three pairs in the case of

A. duodenlae.

Nothing of especial interest happens in the case of the dorsal

nerve in the caudal region of the males.

While sensory endings are more varied and of greater frequency

in the free-living nematodes, they are by no means lacking in the

parasitic species. Unfortunately no detailed study has been made

on the free-living forms and only in the genus Ascaris has a careful

and more or less complete description been given of the sensory end-

ings in parasitic nematodes.

By position there are three groups of sensory endings in most

nematodes, altho one or more, or perhaps all may be lacking in special

cases. Typically then, are found papillae with sensory endings in the

head region, a pair in the “neck” region in a lateral position and

finally papillae in the caudal region of the male. So far as known

there are no nerve endings in the caudal papillae of the females when

such structures occur, but no statement is found in literature which

points to a careful study of this point.

It is out of the place to enter into the discussion between Gold-

schmidt and Deineka and I have little to offer in support or against

either of the two authors. In C. americanus the structures are all

very much simpler and almost totally unlike those in Ascaris; in addi-

tion to this, there is the unfortunate fact that the structures are so

small as to preclude the kind of work done by these two authors

mentioned above. Since there are no ‘“‘head”’ papillae in C. ameri-

canmus one can omit a discussion of their work on the papillae of the

lips of Ascaris; a few words will indicate some of the points brought

out by Goldschmidt, since his work is very complete and differs from

that of Deineka only in interpretation and a few minute points of

anatomy which being so different in C. americanus do not concern

this paper.

The cervical papillae are found laterally in Ascaris and do not

project out into the exterior. They are rounded masses of subcuticula

which have pushed up into the cuticula. In the lateral line, connected

with these papillae, are found two cells, the Stiitzzellen and the

Geleitzelle; the former contains the nerve, which in this case, before

its end, has an enlargement, then it has a deeply staining swelling

CAMALLANUS AMERICANUS NOV. SPEC. 129

and finally a very dark staining ‘“‘Trichterplatte” and an end body

for the very terminal portion of the nerve. The neurofibrillae do not

pierce the covering of the body, the entire structure of the papillae

being below the surface and covered by the cuticula.

In the anal papillae one sees a different structure in the genus

Ascaris. Here the cuticula is projected out into a more or less pointed

papilla and at its periphery is a minute hole leading into a canula

which is a part of the Stiitzzelle and contains the nerve. The sensory

apparatus consists of from one to three nervefibers which are very

simple, There is a chromatic portion of the nerve near its periphery

which stains deeply. The Geleitzelle is lacking.

Looss mentions the innervation of the cervical papillae in A.

duodenale but has studied the entire structure very little. He said

that the pulp of the organ was of subcuticula and that its nerve

supply was from the post-lateral cervical ganglia. No details of the

nerve endings were given. The innervation of the few papillae in

the male tail he stated to be from the posterior ganglia. No details

of their structure were given either.

Strictly speaking there are no true papillae in the tail of the male

but the structures usually referred to under that name are really

ribs, if one considers a papilla as a formation from the entire cuticula,

while a rib is covered, except at its tip, by only the lower layer or

layers of the cuticula.

In C. americanus the cuticula divides into two layers at the

beginning of the lateral alae (Fig. 87), and as has been mentioned

previously, the tubes are short, cylindrical ribs (Figs. 79, 87) which

occupy certain positions extending between the two layers. These

are tubes covered over by the lower layer of cuticula from which

they can be seen to arise in Figure87. Into these tubes the subcuticula

extends.

At the periphery of such a tube is a minute canula which extends

down into the tube one micron and is evidently a product of the

subcuticula. Over the peripheral end of the tube of the lower layer

of the cuticula, there extends the outer layer, so that this end of the

rib becomes enclosed in a cap of outer cuticula.

The nerve endings in the papillae are interesting. They consist

in each case of two minute fibrillae which run in the subcuticula very

close to the inner sides of the tube and terminate in two chromatic

130 T. B. MAGATH

portions (Fig. 91), spherical in shape and lying at the base of the little

canal. If, as in the case of the anal papillae of Ascaris, minute fibers

run into the canula from the chromatic portion, I have been unable

to trace them. Special supporting and accompanying cells for these

papillae could not be found but their innervation is from the posterior

ganglia. In short they seem to be combined ribs and papillae. All

of these ribs have the same kind of structure except that the postanals

and paraanals are shorter and thicker (Fig. 79). Usually the peri-

pheral end of the tube is slightly dilated, this condition being more

marked in the post- than in the pre- anal papillae.

The cervical papillae are but very slightly raised above the general

contour of the body and are not exactly lateral, they being slightly

dorsal to the middle of each lateral line.

The pulp of the papillae lies well embedded in the cuticula and is

in the shape of a little knob, not perfectly smooth in outline, but

slightly bulging, so that in sections one sees little swollen sides of the

knob (Figs. 102, 110, 111). This knob is composed of subcuticula.

Here again I have been unable to locate the two cells found by

Goldschmidt in connection with this organ in Ascaris.

The nerve supply is from the lateral nerve (Fig. 111), a branch

coming off anterior to the papilla and then running into it as a

moderate sized bundle of fibers. These fibers end peripherally in a

deeply staining mass at the termination of the knob. Set into this

structure thru a hole in the cuticul.. is a minute spine which has its

inner end directly above the nerve ending.

Here it would seem that the whole structure is remarkably simple

and its mechanism is easier conceived than in the case of Ascaris, for

in C. americanus there is a spine to communicate the stimuli to the

nerve endings, while in the case of Ascarisit isnecessary to assume that

the stimuli are transmitted to the nerve endings thru the direct effect

on the cuticula itself.

In most free-living nematodes the so-called amphids are found ina

somewhat similar position to the lateral cervical papillae in the

parasitic species and it would be decidedly worth while to study

these two structures in a comparative way to see if the two are

homologous.

CAMALLANUS AMERICANUS NOV. SPEC. iH:

IV. YOUNG FEMALES

In the examination of turtles for C. americanus only twelve young

individuals have been found. These are all females and are near

the same age if the lengths of the bodies, thickness and conditions

of the genital organs are indications of their ages.

They are about of the same proportions as the adults so far as

the body size is concerned and each has already the three spines

(Fig. 7) on the tip of the tail. The esophagus is divided into two

regions and the “bridge cell” is present (Fig. 56). The intestine

shows some pigment and the tailis about 0.1 mm. long. The ovijector

can be seen near the middle of the body and from it stretch out, as

two arms, the beginnings of the genital organs. The oral apparatus

is present, light yellowish-brown in color and somewhat different

from the adult, the details of which will be taken up later.

Seven individuals have been studied in regards to certain measure-

ments which appear in Table IV.

It will be seen that these specimens range in length from 3.3 mm.

to 4.7mm. As they increase in length the diameter of the body

also increases so that the smallest one has its greatest diameter

0.1 mm. which was takena little anterior to the fundement of the

ovijector, the longest worm is0.14mm. thick. It will be seen at once

that the ratio between the length and the thickness is not exactly

constant but very nearly so, which is not the case in the adults.

In these young worms the ratio is about 1:33. It would seem there-

fore as if the mature worms grow longer faster than they grow wider,

while in the young forms both dimensions grow alike. Undoubtedly

the development of the embryos within the uterus accounts for the

difference to a great extent, so in the males the development of the

testis explains this, since elongation is probably more el accom-

plished than enlargment in diameter.

The average of the lengths of the anterior region of the esophagus

is 0.36 mm. which is not greatly below that of the adult females,

while in two individuals this region of the esophagus is as long as in

some adults. In other words this region is almost grown in indivi-

duals in which the oral apparatus is not yet completely formed and

the reproductive organs are extremely immature.

The average length of the second region of the esophagus is also

but little shorter than in the case of adults, but here again one finds

132 T. B. MAGATH

in certain individuals that this region is already as large as in some

adults. The average length of these younger formsis0.46mm. That

the esophagus develops early and to its maximum length is clearly

shown in the case of this species.

While the lengths of the two regions of the esophagus compare

very favorably with those of the adults, the thickness of this organ

is less in the younger individuals as would be expected, since the body

width is so much less. The greatest thickness of the anterior region

of the esophagus in the younger forms is about 0.055 mm. while in

the average of the adults it is about twice as great. The growth then

comes in the diameter of the organ rather than its length. It would

be interesting to know if there is a correlation between the two

but the material at hand is not abundant enough to study this point.

Another very interesting ratio is that between the post- and pre-

vulvar regions. It will be recalled that in the smallest females which

were mature, the prevulvar region was longer than the postvulvar

region. This is also true in the case of every one of the immature

individuals, so that the ratio between the two regions is, in the worm

3.3 mm. long, 1:1.2 and this ratio diminishes with a fair degree of

regularity, considering the few specimens, to a ratio of 1:1.13. The

ratio between the two regions in the youngest mature female in 1:1.1

which is in series with the ratios of the immature specimens. This

demonstrates that at first, even in the very young specimens the

prevulvar region is greater in length and that as the female grows the

postvulvar region outgrows the anterior portion of the worm. This

seems to be due not merely to the presence of the growing embryos,

but rather to the growth of other tissue as well, since the same thing

is noted for the individuals without embryos.

Since the structure of most parts of these young forms is essen-

tially like that of the adults and so much detail has been given for the

latter, only those organs which differ greatly will be discussed here.

Under the section on the cuticula of the adult, that of the young

form has been treated so that there remains but to take up the oral

apparatus and the genital organs; of these the latter will be considered

first.

CAMALLANUS AMERICANUS NOV. SPEC. 133

IV. MEASUREMENTS OF YOUNG FEMALES

Length Length Ratio

Body Body anterior posterior Length Length prevulvar:

No. length thickness portion portion prevulvar | postvulvar | postvulvar

esophagus | esophagus REBIOW ReEIOL lengths

ile 55} 0.10 0.36 0.41 1.8 1.5 1:1.20

oe Shp) 0.10 0.34 0.46 1.9 1.6 1:1.18

She Si6l/ 0.11 0.33 0.44 2.0 ce ileal yy

4 4.0 0.12 0.39 0.48 Pea 1.9 fected

5 4.2 0.13 0.36 0.49 2.3 1.9 ey

6 4.7 0.14 0.36 0.45 2.5 Mop Lethts:

Ue 4.7 0.14 0.40 0.50 2.5 22 shea (als

*Without dorsal and ventral spikes (tridents?) on oral apparatus

Female reproductive organs. The reproductive organs are in the

shape of the letter T with one arm bent over after a short distance

and running back parallel to the cross bar. The T slants posteriorly

(Fig. 9). The upright of the T is represented by a small cavity sur-

rounded by cells, lined near its base with an extremely thin layer of

cuticula. This portion (Figs. 69, 124) is the ovijector and ia the long-

est forms at hand is about 70 w and 25 w wide. In the shorter speci-

mens it is about as long as wide. There are as yet no projection of

the cuticula in this region, so that the typical vulva does not exist,

and there is no opening of the organ to the exterior.

In sections this ovijector shows that it is composed of two layers

of cells (Fig. 69) just as the corresponding region of the adults, but

the inner layer here has at first more than four nuclei in cross section,

differing therein from the condition found in adults. Since by posi-

tion this region is the vestibule and is later heavily lined with cuticula,

the suggestion is here made that these cells in the younger specimens

give rise to this lining. Mediad (Fig. 70) this condition changes so

that there are but four cells seen in cross section as in the case of the

adult and the circular musculature is quite well represented. This is

the region of the vagina and ‘‘trompe,”’ which passes into a very

small tube of cells running off in two strings, one passing anteriad and

the other posteriad.

These tubes do not have a muscular layer and the tubular condi-

tion is not very evident after a short distance (Fig. 85) for the tube

is so small and the cells so large that they fill in the cavity. The

nuclei are especially large as compared with the total size of the cells.

134 T. B. MAGATH

Posteriorly this string of cells continues to a little over half way

between the vulva and the posterior tip of the body and must be the

foundation of the posterior uterine branch. The branch which passes

anteriad represents the future anterior uterine branch, the oviduct

and the ovary. About 0.6 mm. from the vulva it makes a sudden

turn and then runs posteriad to within a short distance of its origin.

This condition was noted in every individual and leads me to believe

that the region from the ovijector to the point of the turn is the foun-

dation of the anterior uterus, for in the adult there always occurs a

turn at the end of the uterus and the oviduct passes posteriad. The

rest of the string of cells is a little thicker but with no differentiation

in it. A muscular layer of the oviduct could not be found in this

material.

The mouth apparatus. Altho some features of the oral apparatus

as it exists in the young individuals have been considered earlier in

the paper, there are other points which call for description here.

In general the same plan of construction is present in the young

worms (Fig. 4) as in the older ones, but in the former the structures

are much smaller and more delicate. Table V gives comparative

figures for both.

V. MEASUREMENTS OF ORAL APPARATUS

PARTS MEASURED YOUNG FEMALES OLD FEMALES

1 bi Si2 Ba ME AR RCIA Be Coad hy 0.070 mm. 0.105 mm.

WOVE Eee A PA THEE UN eee ae 0.080 0.160

Thickness outer laye................0..00000 0.007 0.010

Thickness inner layet....................0:0++- 0.004 0.005

Height of teeth 22k. ioe ee 0.004 0.005

Diameter of, the ring..:2./50.08 0.0.00: 0.050 0.100

Extension of ring below valves.......... 0.030 0.017

The shape and structure of the lateral valves is almost identical

with that of the adults. They are of a slightly lighter color but have

as many longitudinal ridges as in the adults (Fig. 16). The two

layers which have been mentioned before are demonstrable by stain-

ing reactions and these are slightly thinner than in the case of adults

and the ridges are not quite so high. The two valves are united

along their dorsal and ventral margins (Fig. 16, 19) and as in the

case of the adults they are in contact with the cuticula.

CAMALLANUS AMERICANUS NOV. SPEC. 135

The four giant cells are developed at this stage and apparently

can function, for the worms are as tightly attached in proportion to

their size to the mucosa of the host’s intestine as are the adults.

The anterior wings (Fig. 15) are well developed but are smaller

than in the adults and essentially like them. Whether the valves

covers exist or not could not be ascertained from the material at hand.

Two striking differences exist in this young oral apparatus, the

first of which is the condition of the ring. It will be noted by reference

to the table that while the ring is only half so large in diameter, it is

twice as broad as in the adults, that is, it extends further posteriorly

from the margin of the valves. It must be remembered that the

esophagus is narrower in these young forms and the appearance in the

adults is as tho it had pushed out the margin of the ring when it

expanded.

The second characteristic of this mouth apparatus is the absence

of the tridents. In some of the individuals the dorsal and ventral

margins of the valves are perfectly smooth while in others there

projects out a small process from a point just below the union of their

anterior margins. These projections vary in length in different

specimens, the longest being 5 w (Fig. 4). No indication of a cleft

condition has been found and in all individuals they appear as single

spikes. The significance of this will be discussed in the next section

of the paper.

Discussion. From a study of the material at hand it is not wise

to state positively the stage of the larvae which have just been

described. However, the majority of facts indicate that they are,

as yet, in the fourth stage, following the nomenclature of Maupas

(1899). That is to say, they will moult again in the intestine of the

host, just as do the hookworms,

There are some minor objections to this hypothesis; no indication

has been seen in any of the individuals which suggests the preparation

for the final moult. No deposits appear beneath the cuticula, and

the coverings of these forms corresponds to the outer layer of the

cuticula of the adults, as has been previously stated. Further, no

indication of the formation of a second or final oral apparatus has

been noted and the series of dorsal and ventral projections suggests

the start of the tridents, which by further growth would develop into

136 T. B. MAGATH

the adult structure. Finally in no individuals found has anything

been seen which would suggest a moult within the intestine of the

host.

At the same time there is no positive proof that another moult

will not take place. The failure to find intermediate stages is of

course not sufficient ground for assuming that there will be no further

development, and since the individuals are all so near the same

condition of development, one would hardly expect to find different

phases among them.

Up to the present time the most conclusive evidence for consider-

ing these forms as being in the fourth stage, is in the first place, the

growth of the oral apparatus; in particular its growth in outside

dimensions, is very difficult to explain. Before the form reaches

maturity that organ will have to grow to twice the size it is in the

young specimens. The second point in the evidence is found in the

condition of the genital organs. The fact that no opening to the

exterior has been found is very strong proof that this form is not yet

in the fifth stage, especially since the vulva is absent and the ovijector

is so extremely undeveloped. Until more material is found a con-

clusion on this point cannot be reached.

Considering all the information given in this paper on the morphol-

ogy of the adults and the young, it becomes evident that this is a

very important nematode species. In the first place this form is

from a water host, and members of the genus Camallanus are found

parasitic in host of three phyla. The hosts are from among the fishes

batrachians and reptiles, all animals inhabiting water for the greater

part of their lives, and species of this genus have been reported from

both fresh- and salt-water hosts, in Europe, Africa and America.

In the next place this particular species is not only a member of

the genus Camallanus but is in the great superfamily Spiruroidea,

one of the most interesting and fundamental groups which exists.

Upon the correct interpretation and description of its members will

depend in a great measure the future knowledge of nematodes,

especially from a systematic standpoint for this family clearly con-

sists of a group of intermediate species. The divided condition of the

esophagus and the two lateral lipped condition certainly constitutes

one of the fundamental and important divisions of the Nematoda.

CAMALLANUS AMERICANUS NOV. SPEC. 137

The nematode parasites of these water hosts as a rule show

characters which more closely resemble the free-living species, than

the parasites of the strictly land hosts. In this connection, a full

discussion of the significance of the divided esophagus and the

condition of the excretory system has been given in the paper and no

further word is necessary here.

Again, the simplicity of the special endings of the nervous system

indicates primative conditions. Not only are these endings in them-

selves very simple, but they are connected to the exterior while in

Ascaris this is not the case. The rest of the nervous system, while

complete in the essentials, is much simpler than in the case of the

higher species of nematodes, as for example in Ascaris.

Not only does the condition of the excretory system and the

function of the large cells in the esophagus suggest a relationship with

the family Trichotrachelidae, which certainly are not very advanced

above the free-living state, but the reproductive organs of the female

are very much like those of this family. Even in the viviparousness

of the family the genus Camallanus resembles it.

V. THE GENUS CAMALLANUS RAILLIET AND HENRY 1915

The name Camallanus was introduced by Railliet and Henry in

1915 as a designation for the genus Cucullanus of some recent pre-

vious authors which was not the original genus Cucullanus of Miiller

LIL.

Cucullanus was created by Miiller to include two species, para-

sitic in the intestine of the cod, which he named C. cirratus and C.

muticus, and later united in one species which he called C. marinus.

Railliet and Henry have not considered these two names as referring

to one species, thus they have come to select the species cirratus,

because it was first named, as the type of the original genus. Dujar-

din (1845) gave the name of Dacnitis to certain members of the genus

Cucullanus, but by the law of priority his name is no longer in good

standing. Since members of this genus are distinct from those in the

Cucullanus of Dujardin and subsequent authors, Railliet and Henry

have given them a new name, that of Camallanus (camallus, a hood).

The characters of this genus are stated by these authors as follows:

138 T. B. MAGATH

Camallanus Railliet and Henry 1915 (Cucullanus Auct., non

Miiller 1777). Polymyarians (Schneider), secernantes (Linstow).

Cuticula finely transversely striated. Body usually red, obtuse

anteriorly, more attenuated posteriorly. Head with two dorsoventral

valves, limited by a mouth which is a transverse slit and an elliptical

buccal capsule at its entrance; rounded behind, where the internal

walls present longitudinal parallel ridges, usually terminating at the

margin of the mouth in the form of small teeth. Behind this buccal

capsule is a chitinous apparatus in the shape of two transverve bands

united into a sort of band (apophysis Rud.); this part, on each side

has a trident, diverging posteriorly, of which the lateral branches

serve for the insertion of muscles to move the buccal valves. The

valves are terminated by a circular “‘bourrelet”’ (pharynx Duj.) at its

entrance into the esophagus. In general the esophagus is formed in

two portions; the anterior muscular and clear, and the posterior

glandular, more opaque and swollen.

Males with recurved and inrolled tails, carrying caudal alae which

project a little and have a variable number of riblike papillae. A

single spiculum, sometimes accompanied by a very small accessory

piece.

Females larger, tails straight and conical, sometimes with two

subterminal lateral papillae. Vulva projecting from the middle of

the body. Viviparous.

In the development, an intermediate host functions.

Habitat: The adults live in the intestine or stomach of fishes,

batrachians and reptiles. The larvae have been found in the body of

crustaceans (Copepoda) or the larvae of aquatic insects, sometimes

in the eyes of fishes.

Type Cucullanus elegans Zeder 1800=Echinorhynchus lacustris

Zoega 1776.

From the very careful study made of Camallanus americanus,

another species of this genus sent from Africa by Seurat and placed

at my disposal, and the two species, Camallanus ancylodirus and

Camallanus oxycephalus described jointly with Professor Ward, the

author is able to correct somewhat at length the generic description

given by Railliet and Henry. The errors in their account are the

following:

CAMALLANUS AMERICANUS NOV. SPEC. 139

i, The valves are lateral and not dorso-ventral.

ii. The mouth apparatus is not a buccal capsule, but is composed

of a pair of jaws, which indicate an origin from a lipped-condition.

ili. Two transverse bars, the so-called apophysis, do not exist.

iv. No muscles are inserted on the lateral branches of the trident.

v. The bourrelet is the esophageal cap.

vi. The second region of the esophagus is not glandular in the

true sense of the word.

vil. There are two spicula in the males and no accessory piece.

vili. Some females have terminal papillae.

ix. The vulva is not always in the middle of the body, but may be

a little anterior or posterior to it.

As a result the generic description should read:

Cuticula finely transversely striated. Worms usually appear

reddish; obtuse anteriorly, more attenuated posteriorly. Mouth an

elliptical dorso-ventral slit; oral cavity bounded by two lateral,

pecten-shell-shaped valves united posteriorly along dorsal and ventral

margins; internal walls present longitudinal posteriorly converging

ridges, usually terminating at oral margin in small tooth-like spines.

Valves united posteriorly at bases; a circular band-like ring is joined

to valve bases covering the esophageal cap. Valves supported by two

sets of dorsal and ventral prongs, usually three in each set, extending

into the cuticula from valve joints. Two pairs of jaw muscles

extending from the anterior valve margins to the cuticula posterior

to the oral apparatus. Esophagus divided into two regions, anterior

muscular, transparent; posterior opaque, probably excretory in

function.

Males with recurved tails, inrolled and carrying lateral caudal

alae supported by ribs. Two spicula, acuminous.

Females larger than males; tails, straight, conical, sometimes bear-

ing minute papillae. Vulva projecting, on ventral side near middle

of body; one ovary. Viviparous.

In the genus Camallanus Railliet and Henry have placed eleven

species. Two others are usually considered as belonging to this

group of worms but these authors do not include them in their

revision of the genus. Two species have since been described by

Ward and Magath (1917) and the form under consideration in the

present paper adds still another.

140 T. B. MAGATH

The French authors already referred to in this paper have placed

the genus in the superfamily Spiruroidea Railliet and Henry 1915

and in the family Camallanidae Railliet and Henry 1915. At present

this position seems to be satisfactory.

In the past the descriptions of the members of this genus have

been so brief that little information can be found in them save a few

measurements; many forms will therefore have to be placed ulti-

mately among species inquirendae. The species discussed in this

paper suggests very strongly a close relationship with three others

which have been previously described. One of these is a form recently

discussed by Seurat (1915a) under the name Cucullanus microcepha-

lus Duj. On comparing this description with that of Dujardin one

is forced to say that the two forms are not the same if indeed one can

identify any form from the latter’s description. I therefore propose

to call Seurat’s material Camallanus seurati (Textfig. L) in honor of

pe AN

NatisgmnaT

! WELT vy . \

errant =

aouead

Textfigure L (See page 168)

its discoverer. By a close analysis of the facts certain points of

difference come out of a study of the species C. americanus, C.

seurati, C. trispinosus and C. microcephalus.

CAMALLANUS AMERICANUS NOV. SPEC. 141

II. TABLE OF COMPARISONS

ORGAN C. americanus C. seurata C. trispinosus

Magath Magath Leidy

Male Female | Male Female | Male Female

Mouth apparatus

Teri tie sccei. Wert exces 0.089 0.105 0.110 0.140

WWadEhs cei AG 0.120 0.160 0.160 0.180

Prong length............ 0.080 0.105 0.110 0.140 :

Number ridge........... 10 or 12 16

Female tail Three spines Bifid Three spines

Female genital organs-

lengths 1.3-2.1 mm. 3.1 mm.

OvijectOr!.c<.ccscss-s. 2.0-2.7 mm. 1.5 mm.

ROWE cos oeeie iC scccoeese 1.9....3.5 mm. 1.3 mm.

Ration, ovary: ovi-

(LETS ae a ae ee 1:1.0-0.8 utes Ie |

ORE rae ea ee a a 24x25 pu 77x80 pu

Spicula

| ecg aT SS ee 870 pw 840 w 450 u

LDCS eo aa a 310 uw 420 p 120 uw

Embellishment........ Single curved Shaped like “ar-

prong, 75 uw from} dillon d’hame-

from tip con,”’ 60 » to tip

By reference to the descriptions one can make the following

comparisons between C. americanus and C. seuratt:

i. The size of the mouth apparatus is not the same in the two

species. A great deal of importance should be attributed to this fact,

since the structure is so constant in individuals of the same species.

In C. seurati this structure is on the whole rather larger than in C.

americanus.

ii. The female tail is bifid in the former species and terminates

in three spines in the latter.

iii. The ovijector is longer in C. seurati, and the ovary and ovi-

duct are shorter.

iv. The ova are much greater in size in C. seurati.

v. While the right spiculum is perhaps about the same length

in the two species, the left one is not, that in C. seurati being a third

longer. On the right spiculum there is an embellishment, which, in

142 T. B. MAGATH

the American species is, 75 u from the tip and a simple spine in shape;

in C. seurati the embellishment is 60 u from the tip and in the shape

of a battle axe.

There is but one item which can be compared with the new

species and C. microcephalus as described by Dujardin. This is the

size of the head, which is given by him as being 0.1 mm. in the female

and 0.09 mm. in the males. While this agrees with the length of the

mouth apparatus in the new species it is by no means certain that

Dujardin meant to give this measurement for the length of the

valves in his species. Since there are no other data which are char-

acteristic, I regard his form as a species inquirenda.

Mention should be made here that Diesing (1851) adds to the

description of Dujardin’s species the fact that there are three spines

on the end of the female tail, but if the spines are as large as those in

C. americanus it is hard to see how the earlier author failed to see

them. It is by no means certain that Diesing had the same species

that Dujardin described.

The third species is C. trispinosus Leidy (1851). Here again the

description is so meager that one is forced to consider this as a species

inquirenda for no one can identify with certainty this form from the

data at hand. Leidy gave the length of the spicula as being 450 yu

and 120 wu, which would be far too small for C. americanus, but the

three spines on the end of the tail of the female is a little suggestive.

He states definitely that there are eight ridges on either side of a

medium on each valve, while there are only five or six in the case of

C. americanus.

VI. NEMATODE MEASUREMENTS

Perhaps no one factor has contributed more to the chaotic condi-

tion which now exists in systematic nematode literature than the fact

that authors have been content in the past to describe species by

giving a few measurements and a comment or two concerning the

general size and shape of some of the more prominent organs. The

utter folly of describing these complex forms with a running stereo-

typed characterization was pointed out by Looss (1911), who stated

that the trouble lay chiefly in the ‘‘way in which the new species

are described.’”’ He further urged that more stress be laid upon the

descriptions of parts and comparative features in nematodes.

CAMALLANUS AMERICANUS NOV. SPEC. 143

It is not surprising that under the existing conditions some one

undertook to work out a scheme for classification based upon measure-

ments. Cobb (1890) proposed the first and only definite scheme of

this kind. He devised (Textfig. M)a formula to show two kinds of

Textfigure M (See page 168)

measurements, absolute and relative, first the length of the worm

and its thickness at certain points in millimeters, and secondly the

percentage of that length which is represented by the distance from

the anterior tip to definite points in the body. It is clear that this

formula is acceptable for a species only if during the process of growth

all parts increase so as to retain the original proportions, for if this

is not the case then at a given age the worms will yield a different

formula than at other ages. While Cobb has used the formula for

over a quarter of a century he has never attempted to defend it

against the occasional criticisms of other authors, further he has

never recognized that there might be some chance for unequal

growth in different regions.

Fracker (1914), who confined his discussion to the parasitic nema-

todes, published a criticism of the formula which cast considerable

reflection upon it. It is not out of place here to call attention to the

fact that the table given by this author is not arranged with the

animals according to size, so that, since no specific summary of the

table is made, a little difficulty arises in interpreting the figures.

However, he concludes that in Oxyuris vermicularis that “the

locality of the cephalic parts of the alimentary canal tend to vary

from 1 to 4 per cent., about one-third of the maximum.” He also

found a variation of 15% in the location of the vulva, 7% in the anus

and variation in the total length and width of the body.

Looss in the work already referred to, shows quite plainly by a

short table of measurements how futile it would be to try to identify

Uncinaria criniformis or Uncinaria polaris on measurements alone,

144 T. B. MAGATH

and suggests in these cases that while the relative position of the

genital aperture in the female is in some degree constant during

individual growth, this is true in other species in the same genus, and

is therefore a generic and not a specific character. All the other

comparative figures vary during growth and would be of no earthly

value either in the description of the species or of the genus; he has

given the proportions of the length of the body to that of the esopha-

gus, the length of the tail to the body, and the prevulvar to the

postvulvar section. On the other hand he points out that the abso-

lute length of the esophagus is fairly constant, as is also the length of

the spicula and the length of the female tail, as these parts do not

grow much, if at all after maturity is reached or even before. Thus

he shows that in general, proportional figures are of little value,

especially when they are involved in the length or thickness of the

body, and that only a few organs will yield absolute measurements

which can be relied upon. The points to be decided then are, which

organs will yield such useful facts, how far they can be applied, and

whether they are generic or specific in their compass. Such a decison

will be of value because it will furnish some reliable measure or will

eliminate unrealiable ones, which can never do anything more than

confuse literature.

In order to test the formula system further and to see just how

much weight should be placed on measurements, the author under-

took a somewhat extended set of observations on individuals of C.

americanus. For this purpose twenty females and seventeen males,

picked at random from among several hundreds, have been measured

and the ratios and curves worked out with a view of seeing just how

much variation of parts occurs and which measurements could be

relied upon. All of these worms were handled in the same manner

and mounted in damar, so that the errors due to technique should

be about the same in each case. Of course the number used is not

very great but there can be little doubt but that, while the actual

figures would be changed somewhat if more individuals had been

used, the same general conclusions would be reached.*

* The tables of these measurements and the plots of curves are not published in

this paper on account of the limited space. They are, however, on file in the Library

of the University of Illinois, Urbana, Ill., and the Department of Zoology, University

of Illinois.

CAMALLANUS AMERICANUS NOV. SPEC. 145

(1) That an enormous variation occurs in the individuals of

Camallanus americanus becomes evident from a study of the tables

and curves. While the table includes the longest male found, the

longest females are not included; the longest one ever obtained

measured 30.9 mm., which if included, would give a much higher per-

centage of variation than is indicated in the table. Each one of the

females has many embryos in the uteri, so that they must all be

considered as mature females and to give a single measure for the

length of the species would be extremely incorrect. The same holds

true for the males altho they reach a maximum length earlier, for no

embryos complicate the length factor here. Thus it appears that if

the length of this species is to be given in its description, it should be

accompanied with a full statement of how it was obtained, the stage

to which it applies, etc., since the length variations are over 100%.

(2) While it also appears that as the worms increase in length

they increase in thickness, yet one ratio will not express the relation

in all individuals, since the increase in width does not parallel the

increase in length; a variation of 69.4% in the females and 53.8% in

the males was recorded.

(3) The size of the oral apparatus has been discussed at length

elsewhere in the paper and does not appear in the table, for that

region is so constant in size in both males and females that practically

no difference can be detected between individuals of one sex. A

ratio between the length of this structure and the length of the body

or the width of each would be of no significance, since it would vary

so greatly.

(4) The importance of the esophagus from a systematic and

functional standpoint has been pointed out in the paper, but

here it is fitting to note that this organ presents a remarkable con-

stancy in absolute length and thickness in each sex. There seems

to be no tendency for the anterior region of this organ to increase

at all in length after perhaps the time of the assumption of the defini-

tive stage, for extremely young males and females have an esophagus

as long as in the older individuals, but there is some slight tendency

for an increase in diameter, especially up to the time of maturity

from the fourth stage. With the growth of the animals the second

region of the esophagus elongates a little, not greatly and not very

consistently. The data in the table shows the absolute length of the

146 T. B. MAGATH

esophagus given for any individual may vary but 11% on either side

of the average, but that a ratio between it and the length of the body

varies 110.5% in the females and 69.9% in males. Accordingly, in

this species at least, the esophagus obtains its final length early in life

and this is especilly true of the anterior region. The ratio of the

first or anterior portion of the esophagus to the posterior portion

varies a little more in the males than females.

(5) As the females get older and more embryos accumulate and

grow in the uterus, that organ is enormously stretched and tends to

fill the body cavity. As it grows the posterior horn is pushed down

into the tail region; by comparison it is noted that the distance

between the posterior tip of the uterus and the tip of the tail lessens

as more embryos develop. This distance is, in turn, somewhat

inversely proportional to the total length of the body, so that, the

length of this space is, roughly speaking, an indication of the age of

the worm.

(6) The length of the female tail, that is, the distance of the anus

from the extreme posterior tip, is often given as a diagnostic point.

In this species there is a great variation in theitem. The tail growsas

well as the rest of the body but not in the same proportion. Its

absolute length varies 77.2% while in ratio with the length of the body

a variation of 48.6% if found.

(7) As females get older the ratio between the pre- and post-

vulvar region varies 50.0%, the prevulvar portion being more con-

stant in length than the postvulvar region, this latter tending to over

grow in the large individuals. It will be noted that in the young

females the postvulvar region is shorter, while in the older ones this

region surpasses the length of the anterior part. Without doubt the

factor governing this to a great extent is the development of the

embryos.

(8) It is seen that the length of the caudal alae increases with the

length of the body, but that this increase is not so rapid in the caudal

alae, so that a ratio between the two in no way expresses the relation-

ship for all males, nor does the average indicate the true state of

affairs.

(9) It is unfortunate that so few measurements of the spicula

could be obtained, and that it is impossible to measure the length

of the left spiculum in toto mounts. However, it will be seen that

CAMALLANUS AMERICANUS NOV. SPEC. 147

very little difference in length was found in the right one, with no

tendency for increase with the length of the body, the variation in

length, therefore, is individual. The author has dissected out many

spicula of both sides in worms varying greatly in size, and they always

give a length of very nearly 870 » and 310 uw. It therefore appears

that these structures reach a full growth early in the development of

these worms and do not grow later in life. A ratio between them and

the body length would naturally vary considerably.

From these considerations it becomes evident that there are few

if any ratios commonally given that will distinguish individuals of

this species, for the range of individual variation is so great as to

overlap many other species, and then too, no one set of ratios is even

approximately correct or accurate for this species. The absolute

length of the anterior region of the esophagus is reasonably constant,

but as will be pointed out later, does not distinguish other worms of

this genus. The absolute lengths, thicknesses, etc., of the mouth

apparatus and the spicula are very constant and will be shown to be

specific. Lengths, widths and ratios of other parts of the body are

misleading and inaccurate within this species.

In connection with this work it is interesting to compare the two

tables of measurements given by Breinl (1913) for a group of indi-

viduals of Onchocerca gibsoni. One can see from his tables that there

is even more individual variation than in C. americanus since the

esophagus and spicula vary considerably. The ratios between the

parts like those taken in C. americanus show in the same way no

close relation between the growth of the different parts, such as the

length of the body and body thickness, length of the esophagus,

spicular lengths, etc.

From a detailed study of the tables of measurements made from

the records of previous authors and the tables already referred to of

C. americanus the following conclusions seem justifiable:

(1) The measurements which exist are nearly as incomplete as the

descriptions of the species themselves. If the facts in the case are as

in C. americanus these measurements will not differentiate the species

from one another. Even when several measurements are at hand,

some species could not be differentiated from others. In the cases

of A. duodenale and A. conepati there is proof for this statement.

Only when the accurate descriptions of these two species are known

148 T. B. MAGATH

can they be separated, for no major differences are noted in the

measurements of several of the most important organs. It is plain

that two spicula might have the same leng uu, yet one may be heavy

and the other filiform, while one may be straight and the other

spirally bent, conditions which would hardly justify classifying them

within the same species.

(2) Tho the tables are incomplete, there seems to be a tendency

for the esophagus to be fairly constant within a genus, but here and

there are found exceptions. In a few cases the amount of variation

found in individuals within a species has been noted, and here it

can be seen that this variation will include, to a great extent, that

within the genus.

(3) As in the case of the single genus Camallanus, so also with

other genera, the lengths of the spicula furnish the best single char-

acteristic. If a gubernaculum is present, its size adds additional

specific information.

(4) The size of the eggs is of little or no value in the general separa-

tion of either species or genera, as the variation within a species

overlaps that within a genus or even a family. Diagnosis of human

parasites by observation of the eggs, e.g., in the feces, is entirely

practical, for here the number of species involved is relatively small

and the eggs are recognized not by the size alone, but also by their

peculiar characteristics, such as the rough shell of Ascaris, the plugs

at the poles in Trichuris, etc.

(5) It has been shown in the case of the species discussed in the

paper, that ratios of parts and most of the absolute measurements are

quite misleading in a great many respects. Cobb has used in his

formula ratios and absolute lengths and thicknesses, maintaining

that the value of these lay in having a number of measurements and

not, as some authors give, a single item. Since it has now been shown

that organs vary so greatly, a formula for one individual in a species

will be as totally different from that of another as it will be from a

formula of an individual in another species (Fracker 1914). In

pracitcally all the cases given in the table where this variation has

been indicated there is as much individual variation in a single species

as there is in different species within a genus. Altho organs may

increase in thickness as they do in length, the ratio is by no means

CAMALLANUS AMERICANUS NOV. SPEC. 149

constant, and hence these ratios could not be used to designate

species.

(6) It must be admitted, therefore, that the lengths and thick-

nesses of organs are of little value in systematic descriptions of

nematodes, and if such measurements are excluded there remains

only the accurate morphological description of every organ and part of

the form in question. If this kind of information is collected there

can be no doubt that it will yield results, as it has in the organization

of other parasitic groups. Because of the uniformity in structure the

nematodes constitute a difficult division of the animal kingdom for

study, and much has yet to be done before their structures are well

known as those of other parasitic divisions. Characters which are

most constant in individuals should receive the greatest attention and

these are usually found in the anterior and posterior regions of the

body. The internal organs should of course not be overlooked, tho

interest in them does not lie in measurements but in their chemical

characters and morphological structure.

VII. THE CLASSIFICATION OF PARASITIC NEMATODES

In the past only one broad classification of parasitic nematodes

has been offered to the attention of zoologists generally, and it was

proposed by A. Schneider in 1866. He grouped the nematodes into

three main divisions including certain genera under each, and omit-

ting all other subdivisions. In free translation his classification is as

follows:

A. Polymyarit. Many somatic muscles are seen around the body

wall in cross section. In this group are included the following genera:

Ascaris, Eustrongylus, Enoplus, Physaloptera, Heterakis, Filaria,

Ancyracanthus, Hedruris, Ceratospira and Cucullanus (Camallanus).

B. Meromyarii. Muscles of the body built up of eight longitudinal

rows. Under this division are placed Nematoxys, Oxysoma, Oxyuris,

Labiduris, Dermatoxys, Atractis, Spiroxis, Strongylus, Pelodera,

and Leptodera.

C. Holomyarii. The muscles of the body not divided, or divided

only by lateral bands. Anguilla, Trichina (Trichinella), Trichosoma,

Pseudalius, Ichyonema, Mermis, Gordius and Sphaerularia.

Biitschli (1873) showed in the forms grouped as Holomyarii there

is a separation of the ventral musculature due to the presence of the

ventral nerve cord, while he and others have shown that in the other

150 T. B. MAGATH

members of the group one can find the typical longitudinal bands.

As all of these members have many muscle cells in each quadrant

they were placed in the first division and thus only two groups have

resulted from Schneider’s three (Textfig. N). However, this is not

Textfigure N. Diagrammatic representation to illustrate the muscle cell arrange-

ment described by Schneider. a, Polymyarii, b, Meromyarii. The lateral, dorsal

and ventral bands are indicated.

the only objection to the system. Gordius has no place in such a

classification since it is not a member of the Class Nematoda. A

very heterogenous mixture resulted from the combination of the first

and last groups and even in the original scheme, worms which usually

have been regarded as members of the same family or superfamily

are further removed from each other than from those of different

superfamilies or even tribes. Thus the genera Heterakis, Ascaris and

Oxyuris are separated from each other altho Mermis and Filaria are

associated with Ascaris. There is no regard for any general externa

feature in this classification and it is conceded by most systematists

that external features are very important in the separation of groups

in most cases. Further it is evident that the structure of important

organs of the nematodes is not considered by Schneider. In a recent

work Hall (1916) names three families under the superfamily Strongy-

loidea, two of which, Strongylidae and Trichostrongylidae, include

Meromyarian forms while the third, Metastrongylidae, represents a

Polymyarian group. He further described the superfamily Ascaroi-

dea in which the Ascaridae and Heterakidae represent Polymyarian

species while the Oxyuridae are Meromyarians. On the basis of

Schneider’s divisions the Oxyuridae, Strongylidae and Trichostrongy-

lidae would be grouped together, while the Ascaridae, Heterakidae

CAMALLANUS AMERICANUS NOV. SPEC. 151

and Metastrongylidae would belong to the group of Polymyarii. It

would be absurd to think of such a grouping on the basis of present

knowledge of these families. Many other objections can be pointed

out and it is evident that this method of classification is not only

not practical but is entirely artificial.

The following scheme for classifying nematodes was suggested by

von Linstow (1897):

I. Serernentes. Along each side a lateral field with slender basis

which broadens centrad and spreads out over the muscles; in one or

both fields a longitudinal vessel that empties forward in an excretory

pore located in the ventral line. The species live mostly in the

alimentary system when sexually mature, or are free-living. The

lateral fields function as kidneys. Species in the following genera are

included: Ascaris, Physaloptera, Cheiracanthus, Lecanocephalus

Heterakis, Cucullanus (Camallanus), Sclerostomum, Peritrachelius,

Ancryacanthus, Dacnitis (Cucullanus), Spiropteaa, Spiroptenina,

Leptosomatum, Oxyuris, Oxysoma, Nematoxys, Strongylus, Anchy-

lostomum (Ancylostoma) and Trichina (Trichinella).

II. Resorbentes. The lateral lines are broad fields, at times one-

sixth the entire circumference of the body; they have the same

thickness as the muscles and carry no vessels; the excretory pore

is lacking; the lateral fields appear to have an absorbtive function.

The species when mature do not live in the alimentary canal of their

hosts. Here are included Filaria, Filaroides, Dispharagus, Dracuncu-

lus, Eustrongylus, Ichthyonema, Pseudalius and Angiostomum.

III. Pleuromyarii. In the lateral lines stand muscles; esophageal

lumen often a narrow chitinous tube, in some genera the intestine

is entirely lacking. Trichosoma, Trichocephalus, (Trichuris), Gor-

dius, Nectonema, Mermis, and Echinorhynchus.

There are several objections to this grouping. In the first place

the basis of classification is purely artificial and not practical, on

account of the difficulty of preparing sections to demonstrate the

facts in question. The separation of Trichnella from Trichuris is of

course unwarranted. The last group is a grand mixture. Gordius

and the Acanthocephala are not Nematoda and have no place in such

a division. Nectonema should not be considered here either. The

whole system and grouping is-of very little value and should not be

used in the future.

152 T. B. MAGATH

In recent times certain French zoologists have been studying

this group of parasites, creating many superfamilies which they divide

into families, subfamilies, genera and subgenera. So far very little

description of these divisions has been offered and while these investi-

gators have brought to light many interesting and important facts,

it is yet too early to accept their conclusions as final.

The last general division of the Nematoda has been made by

Ward (1917), who divided them into two great divisions, the Tricho-

syringata and the Myosyringata. He defines the former as follows:

With the esophagus of the capilliary type, consisting of “‘a row of

cells pierced thruout the entire length by a delicate tube of minute

caliber.’’ Functionally it is evident that this type of esophagus is

adapted for the passage of fluids, which must flow into the esophagus

without its aid, for no musculature has been demonstrated which

could assist in the process. He has termed the second group, the

Myosyringata, having a pronounced muscular esophagus, with the

fibers contracting transversely to the long axis of the body. ‘‘The

esophagus is tripartite in cross section” and functions for the taking

in of food by opening up a lumen lined with cuticula and triangular

in cross section when open. This causes a powerful suction and

draws in fluids or solid food. This grouping included in the Myo-

syringata all the families of the nematodes save the Trichotrachelidae

and the Mermithidae, which are placed in the Trichosyringata

(Textfig. O).

Textfigure O. Diagrammatic representation illustrating the basis of Ward’s

nematode divisions. a, Myosyringata type of esophagus in cross section. 6, Tricho-

syringata type of esophagus in cross section.

Many authors have suggested in the morphological] descriptions

of nematodes the importance of the esophagus and it has been stated

that as a class, the Nematoda have a tripartite muscular esophagus

shaped like a club. This statement is not entirely true for there are

several forms known in which the esophagus is not of this character

CAMALLANUS AMERICANUS NOV. SPEC. 153

but as has been mentioned before, is of the capilliary tube type. As

yet there is no very good explanation as to how these two types have

arisen, but some very suggestive facts have been learned which at a

later date may help to clear up the matter. However this be, it is

certainly true that for purposes of classification these two types are

easily distinguished and furnish a natural and logical division of the

class. The author has pointed out some of the important features of

the esophagus and it is very fitting that this structure should be

selected as the primary basis for the separation of the nematode

orders. For the subsequent division of these groups a great deal of

investigation will be necessary, yet at the present time some sugges-

tions are not out of place.

Since the smaller group contains forms of such varied nature

there will be no difficulty in finding characters which will differentiate

groups among them. For example, there are forms in which the

males have but one spicule, while others have two, some in which

the males have but one testis. Again there are forms which have

bacillary bands, etc. These are more or less radical departures from

the usual types and careful study will, without doubt, separate out

groups very easily. Since the Myosyringata contain the majority of

nematodes and these are more nearly alike each other than the Tri-

chosyringata, the subdivisions here will be harder to make, all the

more so when the morphological data are so scanty.

Several possibilities have presented themselves, one of which

seems to be particularly fundamental, and uses the oral apparatus for

the separation of groups. It has been’ shown that at least three

distinct conditions exist which are as follows (Textfig. P.):

a r é

Textfigure P. Diagrammatic representation of the three fundamental types of

oral parts which have been demonstrated for certain nematodes belonging to the

| Mysosyringata. a, the dorsalventral type, 6, the lateral type, and c, the circular or

true buccal capsule type.

154 T. B. MAGATH

1. A mouth built up, on the dorso-ventral plan. An example of

this is found in Ascaris, where there are three lips, but so placed that

one is dorsal and two ventral and that the division between the lips

for the mouth opening extends from right to left.

2. Lateral mouth parts, of which the genus Camallanus furnishes

an interesting case. Here the whole structure is devised on the

lateral plan, there being two lateral lips or jaws, with the mouth as

a dorso-ventral slit. It is obvious that the two types are radically

different and can be readily distinguished.

3. In the last type the mouth is arranged on the circular plan.

Here there is a true buccal capsule which is perhaps best understood

in the hookworms. The mouth parts of Camallanus are therefore

fundamentally different from those of the group to which the hook-

worms belong and from a functional standpoint the mouth parts of

the former are really jaws.

Physiologically there seems to be some difference between these

three types. The first are munchers, the second grasping forms and

the last suckers. Other groups based on different conditions of the

oral parts will be found when more species are carefully studied.

A great deal of confusion has resulted from the loose usage of

the terms ‘‘bursa,”’ “alae”? and ‘‘wings.”’? The caudal end of the

male is often modified so that there exists an expansion of cuticula

enclosing the whole posterior end. This is supported by cuticular

tubes filled with muscles, which radiate outwards like the spread

out fingers of the hand (Textfig.Q). For this structure the term bursa

Textfigure Q. Diagrammatic representation to show the difference between a

“bursa” and “‘wings”’ at the posterior end of certain male nematodes. Note that in

a, the bursa is supported by rays which arise from a common locus, while in 6, the

wings are supported by ribs which have separate origins.

CAMALLANUS AMERICANUS NOV. SPEC. 155

should be used. In other forms the cuticula is split laterally forming

narrow wings, which are supported by small ribs of cuticula, or the

wings may meet medially on the ventral side, the median wall of each

wing breaking down and leaving the space open all the way across.

However in either case the supporting structures arise from separate

places along the body wall. These forms should be stated to possess

wings or alae. Still other male nematodes have no modification of the

posterior cuticula save the presence of papillae, while some may not

even have these. Thus at least four subdivisions are possible on the

basis of differences in the male tail. It is also important to note that

corresponding differences are to be noted in the morphology of the

vulva of the females which must be accomodated to the characteris-

tics of the male tail of that species.

Not only does the esophagus furnish a good organ upon which to

base the first separation of groups, but it also furnishes possibilities

for further subdivision. Ward and Magath (1917) have pointed out

some of the possibilities and at present at least four distinct types are

known. The first of these consists of the simple muscular esophagus

without any modifications; in the second type the esophagus has a

bulbous enlargement on its posterior end; in the third type one finds

ceca attached to the posterior end and these may be associated with

ceca from the intestine. Several different varieties may be distin-

guished according to whether the ceca point anteriorly, posteriorly

etc. The fourth type of esophagus modification occurs in those cases

in which one finds regional differentiations in the esophagus, which

may take the form of granular portions, septal divisions, etc. Other

types probably exist but lack of information of a morphological

character necessitates this point being left open.

Generic and specific classification will not be such a great task

once the larger divisions are made, because one deals in the nematodes

with so many different organs and variations of these organs. It is

not the author’s intention to point out these items at the present time,

but the careful study of the exact morphological details of many

species of nematodes will result in as firm a basis of classification of

this group of animals as exists in any other group.

156 T. B. MAGATH

VIII. SUMMARY AND CONCLUSIONS

1. The material used for this study was Camallanus americanus

nov. spec., found in the small intestine of turtles of the following

species and in different parts of the United States of America: Chly-

dra serpentina, Chrysemys marginata, picta, scripta, trossti and

elegans, Malacoclemmys lesuerri and Aromochelys odoratus. The

percentage of infection is nearly eighty and most turtles yield about

fifteen to twenty parasites. They have not been found in the few

soft-shelled turtles examined.

2. The description of the genus Camallanus Railliet and Henry

1915 is corrected and amended according to new facts learned.

3. Camallanus americanus is distinguished from the most closely

related species by the size of the hard parts and their shape, by condi-

tions in the female reproductive system and by the female tail. These

are the only points that can be compared since these are all that are

given by previous authors. A nematode called by Seurat “C.

microcephalus’’ has been shown to be a new species and is named

Camallanus seurati.

4, Evidence is given to demonstrate the inadequacy of nematode

ratios as distinguishing features. Some absolute lengths seem to be

specific, others tend to embrace the whole genus. Descriptions of

nematodes based on a few measurements and ratios of organs are

valueless. Measurements are secondary to the careful description

of the parts of the worms and only in the case of the hard parts can

one place any confidence in absolute lengths or thicknesses. Cobb’s

nematode formula is fallacious, at least as regards the parasitic species.

The esophagus obtains a maximum length early in life, but later

grows somewhat in thickness. The members of the genus Camal-

lanus are poorly described and many cannot be identified from the

descriptions given since they contain only a few measurements and

little of fundamental morphological description.

5. The morphology of every system of Camallanus americanus

has been studied and given in detail.

(a) The cuticula is uninteresting morphologically but from a

chemical standpoint presents a number of important problems. It

has been shown that the cuticula is not chitin but cornein, an albu-

minoid probably related to the supportive tissue proteins of other

animals,

CAMALLANUS AMERICANUS NOV. SPEC. 157

(b) The structure of the subcuticula and the longitudinal lines

has been given in detail; the “filling in” tissue of the anterior end is

not a ligament as Looss supposed, but represents the anterior mass

of the subcuticula, which supports the nervous structure of the anter-

ior end and perhaps forms the oral apparatus. Here there is cell

constancy.

lateral lines, canals and the posterior portion of the esophagus. There

is a single bridge cell which is in contact with the accessory tissue

around the esophagus.

(d) The somatic musculature is of the type designated by

Schneider as Polymyarii, but is on the dividing line between the

types called Platymyaria and Coelomyaria. Part of the somatic

muscles of the ventral half of the caudal end of the male are modified

for helping in the act of copulation. They pull up the ventrum of the

body thus drawing together the two caudal alae, which in turn grip

the projecting vulva of the female.

(e) The intestinal muscle cells are described for the male and

female, and the musculus ani for the female. Their mechanisms

are given.

(f) The mouth apparatus is built on the lateral plan. It is opened

by two pairs of muscles, large and modified from the somatic muscle

cells.

(g) The esophagus is divided into two portions; the anterior

muscular and the posterior granular and probably excretory. Cell-

constancy perhaps exists. The dorsal esophageal gland has a single

nucleus and the excretory tissue of the esophagus has two very large

nuclei. There is an esophageal gland.

(h) The intestine is typical and has in it a great deal of pigment.

There is little doubt but that this pigment is the result of some stage

in the metabolism of blood of the host.

(i) Details of the rectum and thecloacaare given. Looss’ position

taken as regards the rectal cells and his so-called “‘rectal ligament”’ is

not accepted.

6. The chief food of this species is the blood of the host.

7. The red color of the worms is due to the color of the body fluid;

it is without doubt some product from the host’s blood. Tissue

acting like mesenteries to hold the organs in place is present.

158 T. B. MAGATH

8. The reproductive system of the female is interesting. Only

the anterior ovary and oviduct are developed and the latter contains

a seminal recepticle. The species is viviparous and the uteri of the

adults are filled with embryos. Some of these are already contained

within their first skin which is shed a short time after birth.

9. Two unequal, acuminous spicula exist in the males and the

typical nematode male reproductive organs are present. The

spermatozoa in the seminal recepticle are oriented with their long

axes parallel to the long axis of the oviduct. Circular muscles are

around the ductus ejaculatorius and this region probably secretes a

carrying fluid for the spermatozoa.

10. The nervous system is simple and like most nematodes,

consists of a nerve ring, anterior ganglia, longitudinal nerves and

posterior ganglia. The anal ganglion is simple and in the male there

are large posterior lateral ganglia which supply the anal papillae or

ribs. These ganglia are most likely homologous with the three pairs

of posterior lateral ganglia in Ancylostoma.

11. The innervation of the two lateral cervical papillae and the

alar ribs of the male have been studied and the details of the nervous

endings given. Both are connected to the exterior by special

structures.

12. A few young females have been found in the several examina-

tions made for these parasites. They are probably in the fourth stage,

and differ from the adults in three essential respects, viz., the condi-

tion of the cuticula, the oral apparatus and the genital organs. In

them the vulva is not indicated and the opening to the exterior is not

yet effected. ;

13. The importance of the species is pointed out and the members

of the superfamily Spiruroidea are given a place between the free-

living forms and the Trichosyringata, on the one hand, and the

higher forms such as the ascarids on the other. They are therefore

very important and are mostly parasites of water hosts.

14. Possibilities for the future classification of the Nematoda are

shown and Ward’s fundamental divisions, the Trichosyringata and

Myosyringata, are accepted. His secondary division, based on the

condition of the oral parts is deemed logical and natural.

15. Nematode classification cannot hope to make a great advance,

however, until more species are accurately and minutely described.

College of Medicine,

University of Illinois.

CAMALLANUS AMERICANUS NOV. SPEC. 159

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164

egn

T. B. MAGATH

LIST OF ABBREVIATIONS

accesso excretory

around the esophagus

anal ganglion

ano-genita! opening

caudal alae

anus

anterior portion of the esopha-

gus

anterior uterine branch

anterior subventral nerve cell

excretory bridge cell

carrying cell of the excretory

duct

cloacal ganglion

cloaca

cervical papilla

cone tissue, posterior portion of

the esophagus

ductus ejaculatorius

dorsal line

origin of the dorsal nerve

excretory duct

dorsal esophageal gland

dorsal esophageal gland nucleus

extensor muscle of the spiculum

posterior portion of the esopha-

geal excretory tissue nucleus

esophageal valve

nucleus of the ovum

fibrillar portion of muscle cell

fibrous tube enclosing the intes-

tinal muscles

genital fundement

giant muscle cell of the oral

valve

intestine

inner dark layer

inner light layer

intestinal muscle

intestinal muscle nucleus

intestinal sphincter

lateral commissure

lateral cephalic ganglion

lateral excretory canal

lumbar ganglion

lateral line

lateral nerve

left spiculum

lateral valve of the oral appara-

tus

ordinary muscle cells of the

esophagus

musculus ani

musculus ani, nucleus

somatic muscle cell

muscular layer of the ovijector

marginal muscle of the esopha-

gus

nucleus from the spermatozoon

nerve ring

nerve ring cells

nutritional zone

ovum

oblique muscles of the tail of the

male

oviduct

outer dark layer

outer light layer

ovary

ovijector

para-anal papilla

polar body

projections from the lining of the

seminal recepticle

post-anal papilla

posterior portion of the esopha-

gus

posterior uterine branch

pre-anal papilla

post ventral cervical ganglion

projections from the somatic

muscle ceils to the ventral

line

rachis

rectum

rectal cells

rec |

res

rsp

sbt

sil

spc

sperm

sph

SIP,

srg

CAMALLANUS AMERICANUS NOV, SPEC.

rectal lining

esophageal cap or the ring of the

oral apparatus

rectal ganglion

retractor muscles

right spiculum

subcuticular tissue, “filling-in

tissue”’

sarcoplasmic portion of a so-

matic muscle cell

esophageal sphincter

spindle cells lining the ovijector

spiculum

spicular canal

spermatozoa

sphincter

seminal receptacle

sub-rectal gland

165

seminal vesicle

trident

trompe

uterus

vestibule

valve cover of the oral appartus

ventral cervical ganglion

ventral cervical ganglion cell

ventral line

vulva

vulva valve

anterior wing of the oral appara-

tus

shedding skin of the first stage

juncture of the anterior and

posterior portions of the eso-

phagus

166 T. B. MAGATH

EXPLANATION OF FIGURES

PLATE VII*

Fig. 1. Lateral view of the oral apparatus of a male.

Fig. 2. Dorsal view of the oral apparatus of a female.

Fig. 3. Anterior end of a male, lateral view.

Fig. 4. Anterior end of a young female, lateral view.

Fig. 5. Vulva of an adult female, lateral view. The uterus is filled with living

embryos.

Fig. 6. Posterior end of an adult male. Only the right spiculum is shown.

Fig. 7. Posterior end of a young female, immature. Lateral view.

Fig. 8. Posterior end of an adult female. Lateral view.

Fig. 9. Vulval region of an immature female.

Fig. 10. Larva of the first stage in the uterus of the female. Note the four

anterior nuclei.

Fig. 11. Head of a larva beginning the fourth stage. Drawn from life, note the

four anterior nuclei. The reference line is 10 u long.

PLATE VIIIt

Fig. 12. Transverse section thru the anterior portion of the oral apparatus.

Fig. 13. Transverse section thru the middle of the oral apparatus, section in series

with figure 12.

Fig. 14. Transverse section thru the ring of the oral apparatus and in series with

figures 12 and 13.

Fig. 15. Transverse section thru the anterior tip of the oral apparatus of an

immature female.

Fig. 16. Transverse section thru the middle of the oral apparatus of an immature

female and in series with figure 15.

Fig. 17. Detail of the angle of the oral valves of an adult.

Fig. 18. The trident, drawn trom a dissection, medial view.

Fig. 19. Detail of the angle of the oral valves of an immature female.

Fig. 20. The valve cover, drawn from a dissection.

Fig. 21. A spindle cell from the lining of the ovijector.

Fig. 22. The anterior wings of the oral apparatus, drawn from a dissection, slightly

displaced.

Fig. 23. The anterior wings of the oral apparatus, drawn from a dissection.

Fig. 24. The ring of the oral apparatus, drawn from a dissection.

Fig. 25. Structure of a somatic muscle cell from the anterior half of the body,

transverse section.

Fig. 26. Longitudinal section of the cuticula of an adult.

Fig. 27. Transverse section of the cuticula of an adult.

* Each line on this plate represents a length of 40 u, except in Figure 11

+ Each line on this plate represents a length of /0u.

CAMALLANUS AMERICANUS NOV. SPEC. 167

Fig. 28. Structure of a somatic muscle cell from the posterior half of the body,

transverse section.

Fig. 29. Outline of a longitudinal section of the cuticula, to show the striations.

Fig. 30. Transverse section of the anterior portion of the esophagus.

Fig. 31. Transverse section of the posterior portion of the esophagus.

Fig. 32. Longitudinal section thru the cuticula of an immature female.

Fig. 33. Transverse section of the posterior portion of the esophagus, thru the

excretory tissue nuclei.

PLATE IXx*

Fig. 34. Sagittal section thru the anterior portion of the body.

Fig. 35. Frontal section thru the anterior portion of the body.

Fig. 36. Transverse section thru the esophageal valve.

Fig. 37. The two excretory nuclei and gland cell nucleus of the esophagus.

Fig. 38. Longitudinal section thru the lower end of the esophagus and upper end

of the intestine.

Fig. 39. Transverse section thru the anterior cone of tissue in the posterior portion

of the esophagus.

Fig. 40. Longitudinal section thru the juncture of the anterior and posterior por-

tions of the esophagus.

Figs. 41-45. Transverse sections of the lining of the anterior portion of the eso-

phagus, in order passing posteriadly. Figure 41 is at the extreme anterior end and

figure 45 at the extreme posterior end.

PLATE Xt

Figs. 46-55. Series of transverse sections from the same worm, beginning with the

first section just at the anterior level of the esophagus. The last figure in the series is

figure 51, which is thru the bridge cell. The figures are arranged in sequence on the

plate but not in regard to the numbering.

Fig. 56. Transverse section thru the bridge cell of an immature female.

Fig. 57. Transverse section thru lateral line and lateral excretory canal.

PLATE XIt

Fig. 58. Transverse section thru the vulval valve.

Fig. 59. Longitudinal section thru the ovijector.

Fig. 60. Transverse section thru the vulva.

Fig. 61. Transverse section thru the ovijector near the uterus.

Fig. 62. Transverse section thru the ovijector sphincter at the point where it turns

outward.

Fig. 63. Sagittal section thru the vulva.

Fig. 64. Longitudinal section thru the juncture of the oviduct with the uterus

* Fach line on this plate represents a length of JO u, except in Figure 38 where it is

40 p long.

} Each line on this plate represents a length of 20 yu.

t Each line on this plate represents a length of 10 u, except in Figures 65, 66, 67

where it is /00 » long.

168

T. B. MAGATH

Fig. 65. Outline of the beginning of the ovijector and the uterus.

Fig. 66

Fig. 67

Fig. 68

Fig. 69

. Outline of the anterior portion of the reproductive organs of a female.

. Outline of the posterior ending of the female reproductive organs.

. Fertilization of the ovum.

. Transverse section of the anterior region of the ovijector of an immature

female; the beginning of the sphincter.

Fig. 70. Middle region of the ovijector of an immature female, in transverse

section.

Fig. 71.

Fig. 72.

Fig. 73.

An uterine wall cell.

Transverse section of the ovijector; middle region.

Transverse section of the zone of “growth.”

Fig. 74. Transverse section of the germ zone.

Fig. 75.

Fig. 76.

Fig. 77.

Fig. 78.

Fig. 79.

Fig. 80.

Fig. 81.

Fig. 82.

Fig. 83.

Fig. 84.

Fig. 85.

Fig. 86.

PLATE XIl*

Longitudinal section thru the seminal recepticle.

Oblique section thru the oviduct.

Oblique section below the anus of a male.

Transverse section thru the seminal recepticle.

Transverse section thru the ano-genital opening of a male.

Transverse section thru the middle of the body of a male.

Transverse section thru the ductus ejaculatorius.

Spermatozoa.

Transverse section of the anterior region of the testis.

Sagittal section thru the posterior region of the body of a male.

Transverse section of the reproductive organ in an immature female.

Transverse section at the insertion of the retractor muscle on the head of

the right spiculum.

Fig. 87

Fig. 88

Fig. 89

Fig. 90

Fig. 91

Fig. 92

. Transverse section thru the posterior portion of the body of a male.

. Transverse section thru the right spiculum, below the head.

. Transverse section thru the left spiculum below the head.

. Transverse section thru the head of the right spiculum.

. Detail of the external end of a preanal papilla.

. Sagittal section thru the posterior portion of the body of a male and thru

the juncture of the digestive and reproductive tracts.

Fig. 93

Fig. 94

Fig. 95

Fig. 96

* Each

92 where it

PLATE XIIIf

. Distal end of the right spiculum, from a dissection.

. The right spiculum, from a dissection.

. The left spiculum, from a dissection.

. The right spiculum within its sheath, from a dissection.

line on this plate represents a length of 10 yw, except in Figures 84, 87 and

is 20 p long.

+ The lines for Figures 93-101 represent a length of 20 yw, those for Figs. 102-112, a

length of 10 yu.

CAMALLANUS AMERICANUS NOV. SPEC. 169

Fig. 97. Transverse section thru the posterior region of a male, above the region

of the caudal alae.

Fig. 98. Sagittal section thru the posterior region of a male.

Fig. 99. Oblique frontal section thru the posterior region of a male.

Fig. 100. Oblique frontal section thru the posterior region of a male and passing

thru the spicular canal.

Fig. 101. Outline of the anterior ending of the testis.

Fig. 102. Detail of the cephalic papilla to show the entrance of the nerve. The

section is longitudinal.

Fig. 103. Longitudinal section thru the right spiculum, proximal end.

Fig. 104. Transverse section of the seminal vesicle.

Fig. 105. Longitudinal section thru the retractor muscle of the spiculum to show

the type of nucleus.

Figs. 106-109. Details of the nerve cells from the lateral cephalic ganglion.

Fig. 110. Detail of the lateral cephalic papilla, showing the chromatin ending of

the nerve and the ‘“‘trigger.”’

Fig. 111. Longitudinal section thru the posterior portion of the lateral cephalic

ganglion and the cervical papilla.

Fig. 112. The juncture of the seminal vesicle and the ductus ejaculatorius; longitu-

dinal section.

PLATE XIV*

Fig. 113. Sagittal section thru the posterior portion of the body of a female,

passing thru the anus.

Fig. 114. Sagittal section of the posterior region of the body of a female and

passing thru the middle of the rectum.

Fig. 115. Transverse section thru the intestine of a mature female.

Fig. 116. Sagittal section thru the posterior region of the body of a female, and

passing thru the anus. Almost a median section.

Fig. 117. Transverse section in the post-anal region of a female.

Fig. 118. Transverse section thru the posterior third of the body of a female.

Fig. 119. Transverse section thru the musculus ani of a female.

Fig. 120. Transverse section of the same worm as figured in figure 118 and some-

what posterior to the latter figure.

Figs. 121-122. Transverse sections thru larvae of the last part of the first phase,

in the uterus of the female.

Fig. 123. Transverse section posterior to figure 120, and from the same worm.

Fig. 124. Transverse section thru the ovijector of an immature female.

Figs. 125-128. Transverse sections in series thru the rectal sphincter region.

Fig. 129. Transverse section thru the nucleus of the intestinal muscles of a female.

Figs. 130-131. Two sections in series passing thru the rectum of the same female

as figure 118.

* Each line on this plate represents a length of /0 u, except in Figures 113, 114,

116, where it is 40 » long.

170 T. B. MAGAIH

PLATE XV

Fig. 132. Longitudinal section thru the oral apparatus of C. americanus, showing

the mode of attachment in the intestine of the turtle. Photomicrograph.

Fig. 133.. Transverse section thru the oral apparatus of C. americanus, showing

the mode of attachment to the intestine of the turtle. Photomicrograph.

Textfigure F. Illustrating Perrier’s principle of the action of the lateral valves of

Camallanus. After Perrier (1872).

PLATE XVI

Figure 134. Redrawn from Seurat. C. seurati; a, distal region of the anterior

uterine branch; b, terminal region of the posterior uterine branch; e, excretory pore;

z, intestine; 0, ovary; p, postcervical papilla; ¢, ‘‘trompe”’; «, region of the uterus which

is occupied by the eggs.

Textfigure O. Cobb’s nematode formula (Redrawn from Cobb), 6, 7, 8, 10, 6 are

the transverse measurements, while 7, 14, 28, 50, 88 are the corresponding longitudinal

measurements. The formula in this case is:—

nl Ae Doo ZOO uses

Gi Fed Sets Woy Oe

The unite of measurement is the hundredth part of the length of the worm, whatever

that may be. The measurements become, therefore, percentages of the length. The

measurements are taken with the animal viewed in profile; the first is taken at the base

of the pharynx, the second at the nerve-ring, the third at the cardiac constriction, the

fourth at the vulva in females and at the middle (4) in males, the fifth at the anus.

Most of the drawings were made by Mr. C. W. Shepard of the Department of

Anatomy, College of Medicine, University of Illinois.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL <j, \xt4

SOCIETY VOL. XXXVIII eis VN

LATE VII , eae

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIEDY VOLE. XXXVITE

LATE VIII MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL. XXXVIII

MAGATH

PLATE IX

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL. XX XVIII

PLATE X MAGATH

: TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL. XXXVIII

MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL. XX XVIII

PLATE XII : MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCTEDY VOLE2 XX T

PLATE XIII MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL. XXXVIILI

MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCTELTY VOLE. XXXVI

PLATE XV MAGATH

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY VOL XOX ViLLT

Ok i

a we

| |

| | |

| i |

. ' i ; \

| | i

| we

MAGATH

PLATE XVI

TRANSACTIONS

American Microscopical Society

(Published in Quarterly Instalments)

Vol. XXXVIII JULY, 1919 No. 3

FURTHER STUDIES ON NORTH AMERICAN MESEN-

CHYTRAEIDS (OLIGOCHAETA)*

By Paut S. WELCH

PAGES

Part I. Mesenchytraeus hydrius n. Sp.............ccccccecceseceeeeeeesteneeeteneeeeeeeeecseseeeeseescesenes 175

VEER ES Cire ee Ah ey ae OI Racer ER het AY oe ee Oe 175

UTA ETE? ee eee ena erates AKI cenaee cansetatense enaeren scans cana sensc ais 176

Poxtermal Morphology: este ci ceteeeeceieceevevouceqerscccececeseceqeeeercsutecnshnrnanenausnaeves 176

Internal Morpholopiyaccseseeeccececese cesses Bits eta ST Lee, ah Eada 177

Part II. Key to the species of Mesenchytraeus known to occur in North America.... 180

PBUPNOP TAP AY oo concn cc ccspessecenece esse sscasnensecsccsnntesescoungessncvenstuerecnecectisoncotcucortrocaetsemerverserarsaczses 186

Explanation of Plate.................... = hs WNL Rate Sant Me REN, 8 READS cue RUAN iat cwc net 188

Part l. MESENCHYTRAEUS HYDRIUS N. SP.

Habitat

The following description is based upon a collection of enchy-

traeids made by Mr. J. B. Flett in the Mt. Rainier National Park,

June 15, 1917, at an altitude of 3400 feet. This collection contained

91 specimens of which 24 were sexually mature and all apparently

belonged to the same species, definite identification of the immature

specimens being, of course, out of the question. They were found in

slowly moving water in close proximity to melting snow, thus existing

under conditions of low temperature. Mr. Flett reports that some of

the specimens were taken from the sand in the bottom of the stream

and that they offered considerable resistance when pulled from their

burrows. They exhibit the usual crawling movements but dispersal

is facilitated by their ability to loosen, or become loosened from their

hold on the bottom and drift down stream. He also states that they

* Contribution from the Zoological Laboratory of the University of Michigan.

176 PAUL S. WELCH

may possibly occur in the snow but since the color of the living speci-

mens is so nearly that of the snow they would be overlooked easily.

No information is available concerning the abundance of this form

but judging from the number in this single collection, they evidently

occur in large numbers in the Mt. Rainier habitat.

Identity

A study of this annelid based upon dissections and serial sections

showed it to be a new representative of the genus Mesenchytraeus

and another form belonging in the list of enchytraeids having the

striking character of much enlarged and elongated spermathecae—a

character which, as the writer (1916b, pp. 99-100; 1917a, p. 74) has

already pointed out, seems to be restricted to North American species.

The excellent state of preservation and the complete sexual maturity

of 24 specimens made it possible to work out thoroughly all of the

structural characters bearing on the identification of the species.

In many respects, it resembles Mes. seichelli Eisen closely, the impor-

tant differences being as follows: (1) larger number of setae per

bundle; (2) distinctly larger number of somites; (3) much longer

spermiducal funnel; (4) absence of sperm sacs; and (5) marked

difference in the internal structure of the penial bulb; (6) crossed

spermathecae.

External Morphology

The body of Mes. kydrius is cylindrical, elongate, smooth and

approximately of the same diameter throughout except at the extrem-

ities and at the clitellar somites. The length (alcoholic specimens)

varies from 17 to 24mm. inclusive, and the maximum diameter

(clitellar region) from 0.76 to 0.91 mm. inclusive. Externally, the

segmentation is distinct only on the anteclitellar and the posterior

portions of the body. Between inter-segmental grooves, the body

surface is smooth, and free from secondary annulations of any sort.

In the specimens examined, the somites vary in number from 82 to

97 inclusive. The well developed clitellum, occupying 1411-13, is

continuous around the body except for a small area between and

anterior to the penial bulbs where the clitellar thickening is lacking.

The setae conform to the usual condition in the genus Mesenchytraeus,

being distinctly sigmoid and arranged in four rows of fan-shaped

bundles. In the lateral rows, the number varies from 4 to 7 inclusive:

NORTH AMERIGAN MESENCHYTRAEIDS WAT

in the ventral rows from 5 to 9 inclusive. Specialized setae are absent.

The small, smooth, rounded prostomium carries the head pore near

its tip. Color light yellow; pigmentation entirely absent, internally

and externally.

Internal Morphology

Chloragog Cells. In the somites occupied by the elongated sperm -

athecae, the chloragog cells are greatly reduced in number, being

represented only by a few scattering cells or small groups of cells.

These cells are, however, frequently much elongated. In the somites

occupied by the long ovisac, more of the chloragog cells occur and

while their ental extremities cover most of the surface of the aliment-

ary tract, they are diverted from their usual radial arrangement,

the free extremities being pushed around to the dorsal side. Somites

caudad of the ovisac contain elongated chloragog cells arranged

radially about the intestine.

Brain. The brain (Pi. XVII, Fig. 6) lies almost entirely in 1. Itis

about as long as wide, has parallel lateral margins, a truncated

posterior margin, and a concave anterior margin. Two supporting

strands extend to the body-wall.

Nephridia. A nephridium (PI. XVII, Fig. 4, 5) consists of a small

anteseptal region, little more than a mere nephrostome supported ona

short, narrow pedicel, and a large, loosely constructed postseptal part

of the usual mesenchytraeid type. The efferent duct is as long or a

little longer than the entire nephridium and arises from the ventral

surface of the postseptal part about midway ofitslength. There is no

evidence of a reservoir at its ectal opening. There is considerable

variation in the shape of the nephridia in the different parts of the

body, although all conform to the general type described above.

Dorsal Blood-vessel. The dorsal blood-vessel arises in or very

near 18. Distinct swellings occur in several somites just anterior to

its origin.

Spermiducal Funnel. Two prominent spermiducal funnels (Pl.

XVII,Fig.7) lie in the clitellar region and, owing to their size and length,

more than one somite is involved, one and sometimes both extending

into 12. Each funnel is about seven times longer than the maximum

diameter and fills most of the coelomic space in the somites occupied.

Since the space within each somite is insufficient for both funnels, a

178 PAUL S. WELCH

common arrangement is that in which one funnel, bent in a sigmoid

figure, lies more or less transversely in one somite while the other

extends longitudinally into the following somite, septum 11/12 being

pushed caudad to septum 12/13. Usually the extremity of the funnel

is reduced somewhat in diameter and terminates in a thin, flaring

rim. The sperm duct is greatly coiled and massed in 13-14, the

posterior coils lying in the ovisac.

Sperm Sacs and Ovisac. Definitely developed sperm sacs are not

present. In some specimens, 11/12 is reflected caudad in such a way

as to suggest the formation of incipient sperm sacs but such septal

reflections do not extend beyond the confines of the clitellar somites.

A large part of the coelom posterior to the clitellum is occupied by an

extensive, unbranched ovisac which ends in 31-33.

Penial Bulb. The essential features of the ‘“‘mesenchytraeid

bulb” (Eisen, 1905, p. 7) are presented in the penial apparatus (PI.

XVII, Fig. 2, 3) of this species. Inthe retracted condition, each bulb

surrounds a deep invagination which, in transverse section of the worm,

appears as a bifurcating slit, thus forming a mesal compartment and

an ectal compartment, both of similar shape and extent. This double

chamber is lined throughout by a continuation of the external cuticu-

la. The body of the bulb is firm, compact, and composed mainly of

muscle tissue closely built together. A single layer of inner bulb

cells surround the mesal side of the penial lumen but it composes only

a small part of the mass of the organ. Peripheral gland cells are

entirely lacking.

The ectal end of the sperm duct expands into a fusiform atrium

which penetrates the bulb at a point on the mesal surface about

mid-way between the ventral and the dorsal extremities. This

atrium is composed of two portions, the larger fusiform portion lying

in the coelom between the mesal surface of the penial bulb and the

ectal end of the sperm duct proper, and the smaller, shorter portion

enclosed within the body of the bulb. Structurally, the two parts

are similar except that in the latter there is a much greater develop-

ment of the longitudinal muscle-layer. At or very near the junction

of these two parts the ducts from about five large, irregular, multi-

cellular atrial glands enter the wall of the atrium but in the material

at hand it has not been possible to follow these ducts further. The

ducts of these atrial glands are difficult to follow, even outside the

NORTH AMERICAN MESENCHYTRAEIDS 179

atrium, and since the free ends of the glands lie about the base of the

bulb, often in contact with it, they have, at first sight, the appearance

of accessory glands. However, no true accessory glands were found.

Spermathecae. Inform, size, and structure, the spermathecae (PI.

XVII, Fig. 1) resemble very closely those of Mes. gelidus Welch.

In the specimens studied in this connection, each spermatheca is

composed of three distinctly differentiated parts: the duct, the

diverticula, and the ampulla. The duct is straight, slender, and

uniform in diameter, extending caudo-mesad into the anterior part of

6. The ectal opening occurs laterad in 4/5 and is devoid of glands.

At the junction of the duct and the ampulla, two, opposite, elongated,

finger-like diverticula arise. These diverticula are, in the specimens

examined, somewhat shorter than the duct. The ampulla composes

the bulk of the spermatheca, extending caudad through the succeed-

ing somites to the end of 10 and filling the greater part of the coelom

in the somites involved. In fact, the ampulla is, in some cases, longer

than the combined length of the somites through which it extends so

that it may be doubled in varying degrees about the digestive tract.

Constrictions at the septa are well marked but elsewhere the ampulla

is, in the sexually mature specimens, distended with great masses of

spermatozoa, the whole presenting something of a moniliform appear-

ance when isolated from the body of the worm. The two ampullae of

the animal are not symmetrical and may be slightly dissimilar in

length but diversity, such as occurs in Mes. gelidus (Welch, 1916b,

pp. 97-98), was not observed, both extending practically throughout

the anteclitellar somites. In 10, the extremities of the ampullae may

lie in very close contact with the wall of the digestive tract producing

an apparent union with the latter which is very deceiving. Critical

examination of both transverse and longitudinal sections through

these regions has failed to reveal any true connection between the

ampullae and the alimentary canal, the former ending blindly.

Structurally, an ampulla is composed of two regions, a short ectal

portion which adjoins the ental end of the duct and a very long ental

part which constitutes the storage region of the organ. The ectal

portion is rather thick-walled and the lining epithelium is thrown into

a series of transverse folds while in the ental part the wall is reduced

in thickness to the appearance of a mere membrane.

180 PAUL S. WELCH

A remarkable peculiarity of these spermathecae appears in the

fact that the right organ crosses to the left side of the body and the

left organ to the right, the intersection occurring in the posterior part

of 5 or the anterior part of 6, at about the level of the origin of the

diverticula. This phenomenon is a constant feature in all of the

specimens studied and may be regarded as a character of the species.

In an earlier paper (1917a, p. 74), the writer pointed out a similar

crossing of spermathecae in Mes. altus Welch, although in the latter

case these organs pass each other about midway of the length of the

greatly elongated ampullae. Such a crossing of spermathecae must

have been coincident with the development of the organs.

Part Ii. KEY TO THE SPECIES OF MESENCHYTRAEUS

KNOWN TO OccuUR IN NorTH AMERICA

There are two outstanding difficulties which hinder investigation

of the Enchytraeidae, (1) the extremely scattered condition of the

literature invoived, and (2) the incomplete, fragmentary data on so

many of the foreign species described in years past. It is indeed

fortunate that practically all of the North American forms have been

adequately treated and, so far as they are directly concerned, form a

fairly satisfactory basis for work in this country. The world-wide

roster of mesenchytraeid species presents at the present time about

sixty names, although the standing of a few of them is a matter of

uncertainty. Investigations indicate that the genus Mesenchytraeus

is rather generously represented on our continent and with the hope of

facilitating studies involving this genus, the writer has made several

attempts to construct a usable key to all the known species but has

found it a hopeless task, due to the fact that many of the Old World

forms lack both uniformity and completeness in the description of

essential details. In lieu of this more desirable but at present seem-

ingly impossible treatment of the whole genus, the writer presents the

following key to the identification of North American mesenchy-

traeids which may serve at least as a partial basis for work in this

country.

1(26). | Spermathecae'short, confined too peut yee byl ae 2

2 (3) Spermathecae without diverticula; no atrium; no ac-

cessory glands; 1 set of penial glands; 2 sperm sacs;

(2)

4 (5)

(4)

6 (7)

eee)

10 (15)

11 (12)

12 (11)

13 (14)

14 (13)

15 (10)

16 (17)

NORTH AMERICAN MESENCHYTRAEIDS 181

1 ovisac; spermathecae twisted at ectal samee

dorsal blood-vessel arising in 18

unalaskae mince iiSee p. 185)

Srermathedwe with revered SUF ta eh TNS I HON

Spermathecae with 3 diverticula (écasionally 2); ac-

cessory glands present; 8 atrial glands; 1 sperm sac

rudimentary, 1 fully developed sperm sac extending

to 20, not enclosed in ovisac; sperm ducts extending

to 18, only one enclosed within ovisac; ovisac ex-

tending to 22; dorsal blood-vessel arising in 12;

enlarged setae in ventral bundles of 11 By gi

solifugus (Emery)

Evermathecse ith ene idivertionts VALS: 6

Sperm ducts absent; spermiducal funnels Sa Sayed

and opening divectly into penial pores without ducts;

penial bulbs absent; no glands of any sort at col

openings of spermiducal funnels; diverticula of

spermathecae greatly reduced; 1 ovisac and 1 pair of

sperm sacs, both extending posteriorly for several

SOMES HY feo . . nanus Eisen

Sperm ducts present; penal oa Nrpceuts diverticula

ofspermathecae distinct . . . 8

Penial glands absent; penial bulbs composed of ascle

and connective tissues only; atria absent; no acces-

sory plandsii ainsi PEG eden ae kincaidi Eisen

Penial glands present within Benial bulb; atria present. 10

Atrial glands absent. . . moe eet AD

Accessory glands absent; atria wean penta bulbs

; i las Eisen

esa ines Aresene EATS Hig (8 aL 13

Dorsal blood-vessel arising in 19; sperm sacs etendinig

to 16; ovisac extending to 18 fontinalis Eisen (See p. 185)

Dorsal blood-vessel arising in 14-15; accessory glands

very large; copulatory papillae exceptionally prom-

inent: 9s): . . . pedatus Eisen (See p. 185)

Atrial glands eiesen RARE EMO tke

Accessory glands present; 5 Aen pled! both sperm

sacs equally developed, extending to 15-16 and en-

182

17 (16)

18 (19)

19 (18)

20 (25)

21 (22)

222%)

23 (24)

24 (23)

25 (20)

20° (1)

27 (28)

PAUL S. WELCH

closed in ovisac; dorsal blood-vessel arising in 13-14

solifugus var. rainierensis Welch

Boceeaey Mends absent vs .ei) e aed Lem et |

Two atrial glands; spermiducal feels seal) almost

globular, wider than long, bases twisted.

5 eastwoodi Eisen

Mare chen 2 ae Pie spermiducal funnels pie

drical, longer than wide . . . » | 20

Two sperm sacs; no glands at ectal openings int sperm-

athecaet)ciGau ee

Sperm ducts very aka fate as silanes as Eoeeaudieat

funnels; 3-4 atrial glands; sperm sacs extending

hasaat 15 or more somites . . penicillus Eisen

Sperm ducts distinctly longer than spermiducal fun-

nels;6-Satmalilands, .)(:)5 code: Aer fea 23

Spermiducal funnel very long, extending posteriorly

for 6 somites; sperm sacs beginning in 7; length

170 mm.; 105 somites . . grandis Eisen (See p. 185)

Spermiducal funnels very large, length but little great-

er than diameter; sperm sacs arising in usual posi-

tion in clitellar somites and extending to 27 or be-

yond; sperm ducts extending to 21; dorsal blood-

vessel vanisimg "im ZO Orne in, fuscus Eisen

One sperm sac, extending to 16, bifurcating at poster-

ior end; a few glands at ectal openings of sperm-

athecae; spermiducal funnels short, only about 1%

times. longer than diameter; 1 ovisac present,

extending to 16, bifurcating at posterior end, con-

taining sperm sac; dorsal blood-vessel arising in

22723 ee SD Se ohansentaweuee

Spermathecae long, extending through more than 1

SOUMMUCs yu) a = ie Ao oe : |

Spermathecae without dpedicae: hace fae

nels large, about 5 times longer than diameter;

sperm sacs within ovisacs, extending to 15-17; 8

atrial glands; penial glands present; spermathecae

extending to 7-8, no connection with digestive tract;

28 (27)

29 (30)

30 (29)

$1 (32)

32 (31)

33 (34)

34 (33)

35 (36)

36 (35)

37 (40)

38 (39)

NORTH AMERICAN MESENCHYTRAEIDS 183

sperm ducts extending to 19 within ovisacs; 2 ovi-

sacs extending to 22-26; dorsal blood-vessel arising

ia Uae! is ee eee Pee Be albuscn Welch

Spermathecae with fiver ticala SNM ott by ied MaRS.

One small diverticulum on shenmatheca: 5 atrial

glands; no accessory glands; penial glands present;

spermathecae not connected with digestive tract,

extending to 6; 2 long sperm sacs; 1 ovisac

: astaticus Bice

Two divedicula ¢ on eyenna Hees eis ts on Ea

Spermathecae connected with digestive tact by nar-

row ducts in 7-8; 12-14 atrial glands; penial glands

of 1 kind only; no accessory glands . . vegae Eisen

Spermathecae not connected with digestive tract . . 33

Penial glands absent, body of penial bulbs composed

of muscle fibers and connective tissue only; diverti-

cula of spermathecae minute, globular; spermathe-

cae extending to 10; more than 5 atrial glands; no

accessory glands; dorsal blood-vessel arising in 15

orcae Eisen

Penal alends present: Dainericula ap aan

well developed, elongate . . . 35

One prominent accessory gland present at eich penial

bulb; spermathecae extending to 10-12; 8-10 small,

globular atrial glands; penial glands present; dorsal

blood-vessel arising in 16; sperm ducts short, but

little longer than spermiducal funnels; spermiducal

funnels large, length about 4 times greater than

diameter, extending through 2 somites

Opes Risen

Recessaey cede Auceae tide snes ST

Not more than 10 atrial glands; ‘eat mieentanen

absent, o.oo os. 38

Spermathecae sie er ae 7- 8; peemmidaesl eaanele

with length about twice diameter, constricted in

middle; 5 atrial glands; 2 sperm sacs extending to

18 or beyond; 1 ovisac; penial invaginations sim-

ple, undivided! "0°53 20 ess, setenelie’ Bisen

184

39 (38)

40 (37)

41 (42)

42 (41)

43 (44)

44 (43)

45 (46)

46 (45)

PAUL.S. WELCH

Spermathecae extending to 11, crossing each other near

5/6; spermiducal funnels approximately cylindrical,

length about 7 times the diameter; about 5 atrial

glands; no accessory glands; no sperm sacs; 1 ovi-

sac extending to 31-33; each penial invagination

divided into an ental chamber and a similar ectal

compartment, the former receiving the sperm duct;

1setofpenialglands ... . . . .. hydrius Welch

More than 10 atrial glands; body pigmentation present 41

Sperm ducts long, extending to 17; 16—20 small, sessile,

globular atrial glands; spermathecae extending to

9-10; spermiducal funnels trumpet-shaped, length

about twice the diameter, rim long and recurved;

sperm sacs extending beyond 18 . . obscurus Eisen

Sperm ducts short, confined to clitellar somites; atrial

glands elongate ... 9... 43

Spermiducal funnels long, extending cephalad through

3 somites, length about 9 times diameter; sperm

ducts about 3 times longer than spermiducal fun-

nels; spermathecae extending to 10-11; about 16

atrial glands; sperm sacs extending caudad about

30 somites; 1setofpenialglands . . harrimani Eisen

Spermiducal funnels of the usual extent, confinedto11 45

Penial glands exclusively unicellular; spermathecal

diverticula united with ampulla at its ectal end;

spermathecal duct short, diverticula longer than

duct; 2 small groups of glands at ectal openings of

spermathecae; spermathecae extending to 9-11;

spermiducal funnel 3-4 times longer than diam-

eter; sperm sacs extending to 31-35; 1 ovisac, bifur-

cating in 16, extending to 35,enclosing spermsacs _

PA oreeubers Mee Se vaen cet ron Vie it ye gelidus Welch

Penial glands in part multicellular; spermathecal

diverticula attached to middle of long spermathecal

duct, diverticula shorter than duct; spermathecae

extending to 7-8; no glands at ectal opening of

spermathecae; 2 long sperm sacs; lovisac . .. .

maculatus Eisen

NORTH AMERICAN MESENCHYTRAEIDS 185

Discussion

Mes. unalaskac. The only record of this species is the original

description by Eisen (1905, pp. 20-21) based upon specimens col-

lected at Unalaska, Alaska, Aug. 10, 1899, which are described as

“not fully developed.’ The clitellum was absent and there appears

to be reason for questioning the maturity of the sexual organs. In

fact, the structure of the spermathecae and the penial bulb, as

presented in Eisen’s figures (text fig. 1c, e), suggests a certain degree

of immaturity. On the other hand, the connection of the spermathe-

cae with the digestive tract and the presence of well developed sperm

sacs and an ovisac argues nearness to sexual maturity. However,

there is, at present, no alternative other than to give the species this

tentative position in the key.

Mes. fontinalis var. gracilis. Eisen (1905, p. 54) describes a new

variety of this species under the name gracilis but the differences as

described are so slight that the writer questions its validity.

Mes. pedatus. A discrepancy occurs in Eisen’s original description

(1905) of this species which demands notice here. In his key to the

species of Mesenchytraeus (pp. 18-20), pedaius is placed under

“d. No atrial and no penial glands, but many accessory glands at the

lower apex of sperm-ducts.’’ Inthe formal description (pp. 55-57), no

statement appears concerning the presence or absence of penial glands

but, on plate IX, fig. 5, a figure appears representing penial glands

within the small penial bulb and indicated by an abbreviation ‘‘pd.”’

No such abbreviation appears in the explanation of this figure but

an abbreviation “‘p. b/b,’’ not on the figure at all, is explained as

“penial bulb containing unicellular glands.”? There is every reason

for believing that “‘pb” on the plate is a typographical error and

should have been ‘“‘p. b/b.””. The writer regards the figure as indicating

more correctly the structure of the penial bulb, hence the place of

treatment in the key.

Mes. fuscus var. inermis. A variety of this species, described by

Eisen (1905, pp. 49-50) under the name inermis, differs from the

original species in minor respects only.

Mes. grandis. Eisen, the original describer of this species, points

out (1905, pp. 46-47) the close relationship which seems to exist

between it and Mes. harrimani, and suggests the possibility that

186 PAUL S. WELCH

grandis may be identical with harrimani, “the spermathecae having

become accidentally reduced.” The original description was based

upon a single specimen ‘‘which was carefully narcotized and fixed

in sublimate,” implying that it was in good condition. It is not clear

just how a spermatheca might become “accidentally reduced” except

through some unfavorable dissection or sectioning. No statement is

made as to the method of preparation of the specimen for study but

there is a hint that it was dissected. The sperm sacs are described as

beginning ‘‘as far forward as somite VII, where they appear to spring

from the septum VI/VII. They gradually increase in size posteriorly,

except in the somites of the clitellum, where they are thin, even and

tubular. The walls of the sperm-sacs are thick, a cross-section

resembling a cross-section of a spermatheca.’”’ The anterior position,

as described, of the sperm sacs is a very unusual one and, while

Eisen was experienced in recognizing elongated spermathecae, the

writer is inclined to raise the question as to whether the above-

mentioned ‘‘sperm-sacs”’ in the anteclitellar somites might not have

been portions of the spermathecal ampullae. If such was the case

then grandis would fall into the group of species having elongated

spermathecae and possibly might have to be regarded as the same as

harrimani. However, definite settlement of this matter must await

study of additional material.

Mes. beumeri. In the above key no account is taken of a doubtful

record of Mes. beumeri (Mchlsn.) given by Moore (1899, p. 141) as

occurring in the vicinity of Philadelphia.

BIBLIOGRAPHY

Literature Dealing with North American Species of Mesenchytraeus

EIsen, G.

1905. Enchytreide of the West Coast of North America. Harriman Alaska

Expedition, 12:1-166. 20 pl. New York.

Emuery, C.

1898. Diagnosi di un nuovi genere e nuova specie di Anellidi della famiglia degli

Enchytraeidae. Atti della R. Accad. dei Lincei, (5), 7:110-111.

1898. Uber einen schwarzen Oligochaten von den Alaska-Gletschern. Werhand-

lungen der Schweizerischen Naturforschenden Gesellschaft bei ihrer

Versammlung zu Bern den 1., 2. und 3. August. p. 89. D. Sektion ftir

Zoologie.

NORTH AMERICAN MESENCHYTRAEIDS 187

1898. Sur un Oligochete noir des glacier de |’Alaska. Bull. de la Société Zool-

ogique Suisse, (Rev. Suisse Zool., V, Suppl.) pp. 21-22. Genevé

Assemblée générale de Berne.

1900. Uber zoologisches Material vom Eliasberge in Alaska. Die Forschungs-

reise S. K. H. des Prinzen Ludwig Amadeus von Savoyen, Herzogs der

Abruzzenm nach dem Eliasberge in Alaska im Jahre 1897. Ubersetzt

von Prof. Baron G. Locella. Leipzig. Anhang D, pp. 236-245. 1 pl.

Abstract by Th. Krumbach in Zool. Centralbl., 8:812-813.

1900. On Melanenchytraeus solifugus. The Ascent of Mount St. Elias [Alaska]

by H. R. H. Prince Luigi Amedeo Di Savoia Duke of the Abruzzi, Nar-

rated by Filippo de Filippi. Illustrated by Vittorio Sella and Trans-

lated by Signora Linda Villari with the Author’s Supervision. Westmin-

ster. Appendix D, pp. 224-231, 1 pl.

MICHAELSEN, W.

1900. Oligochaeta. Das Tierreich, 10 Lief. XXIX, 575 pp. 13 fig. Berlin.

Moorg, J. P.

1899. A Snow-inhabiting Enchytreid (Mesenchytreus solifugus Emery) col-

lected by Mr. Henry G. Bryant on the Malaspina Glacier, Alaska. Proc.

Acad. Nat. Sci. Phil., pp. 125-144. 1 pl.

Situ, F. and WEtcH, P. S.

1919. The Oligochaeta collected by the Canadian Arctic Expedition of 1913-

1918. Part II. The Enchytraeidae. (Jn press).

WE cH, P. S.

1916a. Glacier Oligocheta from Mt. Rainier. Science, 43:143.

1916b. Snow-field and Glacier Oligocheta from Mt. Rainier, Washington. Trans.

Am. Micr. Soc., 35:85-124., 4 pl.

1917a. Enchytrexide (Oligocheta) from the Rocky Mountain Region. Trans.

Am. Micr. Soc., 36:67-81.

1917b. Alaskan Glacier Worms (Oligocheta). Bionomical Leaflets, McGill Uni-

versity, Montreal, No. 2, pp. 5-8.

188 PAUL S. WELCH

EXPLANATION OF PLATE

ABBREVIATIONS

ate atrium

ay gi _ atrial gland

dso spermathecal diverticulum

in b cl inner bulb cells

m muscle tissues within penial bulb

pen bi penial bulb invagination

pen po penial pore

spr spermatheca

PLaTE XVII

Mesenchytraeus hydrius n. sp.

Fig. 1. Diagram of 4-10, showing position, extent, gross structural features, and

crossing of the elongated spermathecae.

Fig. 2. Penial bulb and associated structures. Somewhat diagrammatic.

Fig. 3. Penial bulb as it appears in transverse section of worm. Bulb in retracted

condition.

Fig. 4. Nephridium from a postclitellar somite.

Fig. 5. Nephridium from an anteclitellar somite.

Fig. 6. Brain.

Fig. 7. Spermiducal funnel.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XX XVIII

WELCH

THE LATERAL LINE OF POLYODON SPATHULA*

By Homer B. LATmiwer

CONTENTS

PEWERISEONIGAL ese Oya UN IN NAN DAN IL AROE MRC RU NIB CCE I LAN OTRO REN 197

BieiMatertaland: Methods). i) 1(u2s ual Maes Nilsen mi) OW AMM 2 RU nae 199

TH Generabotructureior the Lateral Lines, 6. U uy VOB Ea 200

ap) pneleonpitudinal Series Aen Alp wun UG Ge BT euntInG CAD Mg 201

Dyjbe Prarisverse Series ey fo NOV ICTs Sun eae San ia CAD BMA 204

er SUTOLO AE eee ethene cu Net LUMEN IL) AB Ali ee 1 Raa NO a CaM 212

een) toto hoprapy nye pein | oar te aul nt CARNAL ERD cael VC Sri ot N ea ARE A os! ase 213

I. HisToRIcAL

The lateral line system of fishes has long been known as a system

of dermal canals lying upon the head and along the sides of the body.

It was described in 1664 by N. Stenois and until 1850 it was regarded

as an organ for the secretion of mucus.

Leydig (’50) describes the general appearance and location of the

canals, the nerve supply and histology and concludes that it is

sensory in function. Vogt (’56) advanced the theory that it was

connected with the lymph system, altho he agrees with Leydig that it

is not a mucus producing organ. Franz Schulze (’61) in working on

the lateral line organs of Perca fluviatilis agrees with Leydig and Vogt

in calling it a sensory structure, but the following year M’Donnell

(’62) states that it “‘secretes some fluid which is poured forth from the

skin as an excretion.” Following these earlier workers we have the

papers of R. R. Wright, Allis, Collinge, and Cole. R. R. Wright

(84) in describing the lateral canal of Amiurus, gives the number of

pores and nerve hillocks (sensory ridges) as equal in number and

forty on each side of the fish. In the specimens of Polyodon examined

I find that the number of sensory ridges is much greater than the

number of the branchlets and not equal as he found them in Amiurus.

*Studies from the Zodlogical Laboratory, of the University of Nebraska. No.

122.

189

190 HOMER B. LATIMER

The condition of the canal as found in Amia calva by Allis (’89)

resembles in many ways that of Polyodon. He describes the canal

as turning downward at the caudal end and passing between two

tail fin rays and not in a ray as in Polyodon. In fig. 49, Plate XLII

he shows the ridges as intermediate between the branchlets, not at

the bases of the branchlets as was found in Polyodon.

In the description of the lateral line of Polyodon folium by

Collinge (’94) he states that ‘‘during its course from the caudal to the

cranial region there is a gradual but distinctly appreciable enlarge-

ment in its diameter.’’ He gives the number of branchlets as varying

from 32-35, part on the ventral side and part on the dorsal side. The

smallest number found in Polyodon spathula was 41. He found the

branchlets from 12-17 mm. in length, while in the specimens of

Polyodon spathula which I have examined none of the branchlets

exceeded 9 mm. in length, but this may be due to the comparatively

small size of the specimens examined.

Mention should be made of the work of G. H. Parker (’02 and

04) upon the function of the lateral line organs. In the summary of

his paper he says, ‘““The lateral line organs are stimulated by water

vibrations of low frequency—6 per second.’ Some other work has

been done on the physiology of these organs and a good deal in

attempting to determine the embryology.

Brohmer (’08) in working with embryos of Spinax niger found that

in 36 mm. embryos the lateral line, seen in toto, appeared as a white

line. In the 45 mm. stage he found that the white dots along the

sides of the lateral line which he had supposed, in the general examina-

tion to be Lorenzian ampullae, were in reality the openings of the

branchlets. He says (free translation) ‘‘On either side of the lateral

line, were noticed rows of white spots, the openings of the sense

bodies. The openings arranged themselves with somewhat of

regularity on the right and left sides. The adjoining bodies united to

form the lateral line, and the communicating cavities formed the

lateral canal.” If this represents the embryonic condition of the

canal of Polyodon as well as that of Spinax, it would account for the

position of the branchlets always on the dorsal or ventral sides of the

canal, never on the lateral side, which would naturally be expected

if the branchlets were simple evaginations from the canal, or if they

were the tubes connecting the depressed organs with the surface.

THE LATERAL LINE OF POLYODON SPATHULA 191

This would also explain the enlargement of the canal at each sensory

ridge, as well as the tendency of the sensory ridge to pass up onto the

opposite side of the canal to that from which the branchlet is given

off. The closing of the openings of some of the bodies would account

for the fact that some of the ridges are without a branchlet. In speak-

ing of this alternating opening of the bodies upon the right and the left

sides he says that the two sided opening of the canal perhaps aids in

the determination of the direction of the sensation, since the stimulus

will have a different effect upon some of the bodies or nerve ridges

than upon others whose branchlets are turned away from the source

of the stimulus. In this way the fish is enabled to orient itself with

respect to the stimulus. An interesting fact in connection with this

theory is that in the Polyodon, a bottom swimmer, the majority of

the branchlets come from the ventral side of the canal, which is not

what would be expected if this suggestion is correct.

Johnson (1917) in his description of the lateral line system of

Selachians finds that the sensory epithelium is practically uniformly

distributed along the canal except for the decrease in size toward the

caudal end, and that it is located on the superior medial part of the

canal. He finds the branchlets (tubules he calls them) all opening

from the ventral side of the canal.

Il. MATERIAL AND METHODS

The material used in this investigation consisted of the right

lateral lines of two Polyodon spathula. Both lateral lines had been

removed from the fishes, so there was no way of knowing definitely the

total lengths of the specimens. In order to gain some idea of the size

of the fish from which the lateral lines had been taken thirteen

Polyodon of various sizes were examined. The total length of the

fish from the tip of the “‘bill’’ to the tip of the caudal fin, as well as the

length of the lateral line measured from the first branchlet posterior

to the gills to the termination of the canal upon the dorsal part of the

caudal fin, was carefully determined for each specimen. The length

of the lateral line expressed as a percentage of the total length of the

fish was found to be approximately 47%, the average for the thirteen

specimens examined. Thus the length of the larger fish whose lateral

line was 17 inches long must have been about 36 inches in length,

and the smaller fish with a 7. inch lateral line must have been about

192 HOMER B. LATIMER

14.5 inches long. Of course, this gives only an estimate of the

lengths of the fish. All the measurements were made from preserved

material.

The two lateral lines had been removed by cutting a strip about

three quarters of an inch wide, in the case of the larger fish, and one

half inch wide from the smaller fish, and deep enough in both cases to

ensure getting all of the dermis. The lateral line from the larger

fish had been fixed in Formol-Corrosive-Acetic and had been kept in

80% alcohol for about a year. The shorter lateral line had been

preserved but a short time in alcohol, after fixation in Trichlor-

Acetic.

Charts showing the number of the branchlets and tube pores as

well as the lengths of these branchlets and the intervening lengths of

the canal were drawn to scale before the strips were cut (Figs. 1 and

2). Both strips were placed in acid alcohol (.5% HCl. in 70% Alco-

hol) for from two to four hours and then stained in toto in Haemacal-

cium for from 24 to 36 hours. The canal from the larger fish was then

cut into convenient lengths run thru the alcohols and xylol, imbedded

in paraffin and cut longitudinally. The other canal, stained and

imbedded in the same way, was cut transversely. The longitudinal

series was cut ten microns in thickness while the transverse series

was cut twenty microns. The larger canal was the better preserved

altho neither was in first class histological condition. The epidermis

of the strip containing the shorter canal was nearly all destroyed in

attempting to remove the hardened opaque mass of mucus so that

the branchlets could be distinguished, with the aid of a dissecting

lens, in making the surface drawing. The epidermis of the other

strip was in a little better condition. The lengths of the sensory

ridges in the lateral canal, which was cut longitudinally, were deter-

mined by means of an ocular micrometer; the lengths of the ridges

in the transverse series were determined by counting the number of

sections containing each ridge.!

1This work was done some time ago in the Animal Biology Laboratory of the

University of Minnesota, at the suggestion of Professor Henry F. Nachtrieb, to whom

I wish to express my most hearty thanks for his stimulating and very helpful advice.

I had hoped to get more material and then make a more complete histological study but

there seems to be no immediate prospect of doing this.

THE LATERAL LINE OF POLYODON SPATHULA 193

III. GENERAL STRUCTURE OF THE LATERAL LINE

The lateral line system as described by various investigators con-

sists of several cranial branches, a main branch, and the lateral

branch, or lateral line. The lateral line was the only part of the lateral

line system studied. In Polyodon spathula the lateral line unites

with the main canal by passing dorsad to the gills, and extends caudad

from the gills along the sides of the fish. In the anterior portion of the

body it is situated upon the dorsal half of the fish, but as it approaches

the tail it comes to lie about half way between the dorsal and ventral

portions. It is deflected downwards slightly as it reaches the tail,

but upon entering the dorsal part of the caudal fin it runs upward,

parallel to the fin rays and terminates a short distance from the tip

of the tail. The lateral line, in preserved specimens, when viewed

from the surface, appears as a whitish line extending along the sides

of the fish, and the branchlets appear as shorter white lines extending

dorsad and ventrad from this. These branchlets divide, as a rule

terminating in the tube pores. (Figs. 1 and 2).

The number of branchlets varies in different specimens and even

on the two sides of the same specimen. The number of branchlets

found on four specimens of Polyodon is given below:

Right side. Left side.

41 41

56 50

64 61

Se 46

For convenience the lateral line from the larger fish, which was cut

longitudinally, will be spoken of as the ‘‘Longitudinal series,”’ and the

lateral line from the smaller fish which was cut transversely will be

spoken of as the ““Transverse series.”’

a. The Longitudinal Series

The lateral line from the first branchlet posterior to the gills to

the last branchlet on the caudal fin was 42.85 cm. in length. Thruout

this entire length there were in all, 54 branchlets, ten of these were

given off from the dorsal side of the canal, and 44, from the ventral

side of the canal. In no instance did a branchlet start from the

lateral or medial sides of the canal. Four of the ventral branchlets

passed between the canal and the epithelium and terminated in the

194 HOMER B. LATIMER

epithelium, either entirely, or partly on the opposite side of the canal.

All four of these branchlets were in the anteriorregion. Onaccount

of the amount of cartilage in the tail it was impossible to obtain a

series of the posterior part of the canal; so the length of the canal which

was sectioned, was 37.9 cm. in length and contained 44 branchlets.

These branchlets terminated in from two to seven tube-pores. The

more anterior branchlets, as a rule, had the larger number of pores,

and hence were more branched. No opening of these branchlets

was more than 9 mm. distant from the canal. Thus but a relatively

narrow band, not over 18 mm. wide, contained the entire lateral

canal and its branchlets. The cartilaginous nodules and “‘pit organs”

could also be seen in the surface view, situated either over or near the

canal. The nodules seemed more numerous in the posterior part,

where they were scattered irregularly, while in the anterior part, they

were nearly always found lying over the lateral canal. These nodules

and ‘‘pit organs” will be described a little more in detail later on.

The features most clearly shown in the longitudinal sections were,

the relation of the cartilaginous rings surrounding the canal and the

unevenness of the sensory ridges, (fig. 4). The determination of the

lengths of the ridges was a little more difficult than in the transverse

series, due to the fact that it was hard to get the sections perfectly

parallel to the canal. The lateral canal itself was not perfectly

straight. Where a branchlet was given off there was often a slight

divergence toward the side from which the branchlet originated.

These irregularities in the plane parallel to the surface were, however

far less pronouncéd than the wave like course in the plane perpendi-

cular to the surface.

The cartilaginous rings surrounding the lateral canal thruout its

entire length were of two kinds, (a) ring-like cartilages which enclose

the canal in the troughs, or parts of the canal most distant from the

surface, and (b) cylindrical or “‘drainpipe-like”’ cartilages, found

always at the crests or parts of the canal nearest the surface. The

ring-shaped cartilages enclosed those portions of the canal between

the ridges, while the sensory ridges were always enclosed in the

cylindrical cartilages, (fig. 4). The distance from one crest to another

in the anterior part of the canal varied from 3.2 mm. to 4.5 mm.

The crests of the canal very often came up to the base of the epithel-

ium while the troughs were from .24 mm. to .48 mm. distant from the

THE LATERAL LINE OF POLYODON SPATHULA 195

base of the epithelium. Between the cylindrical cartilages, or

“drainpipe-like bones,’’ as they were called by Collinge (’96), there

were from 12 to 14 of the ring-shaped cartilages in the anterior part

of the canal. In the body region, at the base of the caudal fin, there

were but one or two and sometimes none of the ring-shaped cartilages

between the long cartilages. This change in the number of the ring

cartilages was not abrupt, for from the middle of the body region

there was a gradual diminution till the extreme condition, the absence

of the ring cartilages was found at the base of the tail.

The cylindrical cartilages terminated either at the crest or a little

caudad to it at the place where the canal began to descend. From

this point they extended cephalad and mediad often reaching to

nearly the lowest part of the curve. Thus the sensory ridges which

lay primarily within these cartilages were situated in that part of the

canal facing the anterior. The sensory ridges as well as the cylindrical

cartilages in some instances extended a short distance caudad to the

crest.

The branchlets were always given off from either the dorsal or the

ventral side of the cylindrical cartilages at a point near the surface.

A continuation of the connective tissue extended out surrounding the

branchlet for some distance. The sensory ridge extended but a short

distance caudad to the origin of the branchlet. Neither the sensory

ridge nor any part of it extended out into the branchlet. This relation

of the sensory ridge to the branchlet was followed out more carefully

in the transverse series and will be discussed later. The sensory

ridges which were situated in the cylindrical cartilages from which

branchlets were given off showed apparently no difference in structure

from those ridges which were not near a branchlet. Every branchlet,

however, originated from one of the cylindrical cartilages containing

a sensory ridge. In some instances branchlets arose from adjoining

crests, while as many as five, in one instance, and often two, three

and four ridges intervened between two ridges which were located

at the base of a branchlet.

From one crest in the anterior part of the canal a small tube was

given off from the lateral side of the canal. This was much smaller

than the branchlets, both in length and in diameter. The sensory

ridge and canal showed no special modifications at this point. It

resembled a similar structure found in the transverse series, which

196 HOMER B. LATIMER

will be described more fully in that part of the paper. This opening

was not counted as a branchlet.

That part of the canal which was cut was 37.9 cm. in length, and

contained 126 sensory ridges and 44 branchlets, or an average of 2.86

ridges for every branchlet. The branchlets were not distributed

uniformly, for there was a tendency for the branchlets to group them-

selves.

The measurements of the sensory ridges will be given more con-

cisely and perhaps just as clearly in the following table. The eleven

groups are the eleven pieces into which the lateral canal was cut for

convenience in sectioning. The first column shows the number of

branchlets in that section, the second column gives the number of

sensory ridges, the third, the average length of the sensory ridges

found in that division, and the fourth and fifth columns give, respec-

tively, the longest and shortest ridges found in each division.

Branchlets Ridges Av. Length Longest Shortest

5 15 1.194 mm. 1.666 mm. .830 mm.

6 9 1.473 mm. 2.075 mm. .797 mm.

3 11 1.045 mm. 1.328 mm. .581 mm.

4 11 1.004mm. | 1.411 mm. .498 mm.

4 12 .837 mm. 1.666 mm. 415 mm.

4 14 .652 mm. 1.328 mm. .249 mm.

4 15 655 mm .896 mm. .332 mm.

4 14 .792 mm. 1.411 mm. .581 mm.

5 13 .745 mm. 1.162 mm. .249 mm.

2 6 .766 mm. 1.162 mm. .581 mm.

3 6 .830 mm. 1.079 mm. | .415 mm.

44 126 .908 mm.

This table and the chart of the lateral line (fig. 2) do not show the

same number of branchlets but it must be remembered that only a

part of the lateral canal was sectioned, or that part between the

second branchlet from the anterior end and the eighth from the

caudal end. There were 54 branchlets in the entire canal which

measured 42.85 cm., and but 44 branchlets in the part sectioned

which measured 37.9 cm.

THE LATERAL LINE OF POLYODON SPATHULA 197

b. The Transverse Series

The material used for this series was the right lateral line canal

of the smaller fish, as stated above, and on account of the smaller

size of the fish as well as the hardened opaque mucus covering the

skin, it was much more difficult to chart the line and branches. It

was possible, however, to make a series thru the entire lateral canal,

from the gills to its termination upon the caudal fin.

The canal measured 18.1 cm. from the first branchlet posterior

to the gills to the last branchlet on the dorsal part of the caudal fin.

Thruout its entire length there were 61 branchlets, 53 of which were

given off from the ventral side, and 8 from the dorsal side, (fig. 1).

There were thirteen branchlets in the tail, all of which were on the

ventral side of the canal. In studying the sections an additional

branchlet was discovered originating from the lateral side of the canal.

This branchlet resembled the others in everything but its position,

which was between the canal and the epidermis, and parallel to the

canal, so that it was not seen while making the surface drawing. This

would raise the total to 62 branchlets. All of the branchlets were less

branched than in the larger specimen, terminating in but from one to

three tube pores. The majority of the branchlets did not branch at

all, or else had a short dichotomous branching. Many of the branch-

lets would remain unbranched thruout nearly their entire course,

then very near the end they would divide terminating in from one to

three tube pores. The two charts show a marked difference in the

branching of the branchlets and the number of tube pores, tho the

branchlets are distributed along the canal in much the same way.

Immediately posterior to the gills, the first two or three branchlets

were not so close together as the next ten or twelve. Then followed

a longer region extending nearly to the base of the caudal fin, with the

branchlets more scattered. On the body, at the base of the caudal

fin and on the fin itself, the branchlets tho shorter and less branched,

were closer together. No branchlet terminated more than two and

one-half or three millimeters from the canal: in other words, the

entire canal and its branches were contained in a strip six millimeters

wide on the body, and gradually diminishing posteriorly, till not over

three millimeters wide on the caudal fin. As was found in the other

series, the more anterior branchlets had a tendency to turn caudad

after leaving the canal. Only one of the branchlets in this series

198 HOMER B. LATIMER

passed laterad to the canal in reaching the surface on the opposite

side of the canal. In one case two branchlets were given off from the

same ridge, one from the dorsal side, and the other from the ventral

side of the canal.

The number and arrangement of the canal cartilages was not so

carefully noted in this series. Asin the longitudinal series, the sensory

ridges were always found in the cylindrical cartilages, which were

separated from each other by a greater number of ring-shaped

cartilages in the anterior part of the canal than in the poster-

ior part. The canal had the same wavy course tho perhaps not

quite so marked as in the longitudinal series. In this series the crests

scarcely ever came in contact with the dermal epithelium. The few

exceptional cases where the cartilages of the canal came up to the

epithelium were just about as numerous in this series as were the

exceptions in the longitudinal series, or those cases where the carti-

lages did not come to the surface. In a short portion of the canal

about one-third of the distance caudad, the top of the canal varied

from .08 mm. to .22 mm. distant from the base of the epithelium.

These figures do not mean that the above is the variation in one

curve, but the longest and the shortest distances from the base of

the dermal epithelium in the two slides in which the distances were

measured. The difference between a crest and an adjoining trough

would probably be quite a little less.

In this series as in the other, the sensory ridges were found in the

anterior slope of the crest, terminating at, or just posterior to, the

base of the branchlet, or at the crest if no branchlet is given off,

and enclosed in the cylindrical cartilages. As before, there was no

apparent difference in the structure of the sensory ridge whether a

branchlet was given off or not. In the case of the double branchlet,

or the one where a branchlet was given off from each side of the canal,

the sensory ridge was a normal one, being .380 mm. in length. The

average for this region was .336 mm. and the longest ridge was .600

mm. in length and had no branchlet. The number of sensory ridges

intervening, between ridges in the cartilages from which branchlets

were given off, varied from none to as many as six in one case (two-

thirds of the distance back on the body). In seventeen instances

there was no intervening ridge; in fourteen instances there was one

ridge; in eleven instances there were two ridges; nine instances,

THE LATERAL LINE OF POLYODON SPATHULA 199

three ridges; five instances, four ridges; two instances, five ridges,

and in one instance there were six intervening sensory ridges. As

many as three consecutive ridges were found with branchlets, again

showing the grouping of the branchlets.

The method of arrangement found in the body region seemed to be

very much altered in the tail region. There were nine branchlets on

the caudal fin with no sensory ridge at their bases. In two places two

adjoining branchlets were found with no ridge at their bases nor an

intervening ridge. The arrangement of the cartilages seemed less

typical in the caudal fin. The canal toward the later part of its

course in the caudal fin seemed to enter what might be called a jointed

cartilaginous, fin ray. The differences in the epithelial lining of the

canal will be described later.

The location of the sensory ridge in the canal was shown very well

in this series (figs. 6 and 7). A narrow circular space filled with an

indifferent mesenchymatous tissue, separated the cartilaginous

canal from the inner or epithelial canal, which consisted of a single

layer of flat epithelial cells thruout about one-half to three-fourths

of the circumference of the canal, the remaining portion being occu-

pied by the columnar epithelium or sensory ridge. The sensory ridge

was uniformly found on the medial side of the canal, tho in some

places there was a slight tendency toward the movement of the ridge

up onto the side of the canal opposite to that from which the branch-

let was given off. In one case, the anterior end of the ridge started a

little way up on one side of the canal and in going caudad it passed

to the normal position on the medial side of the canal and then passed

up onto the opposite side from that on which it started. The longi-

tundinal band of columnar epithelium, or sensory ridge, was always

raised up upon a thicker mass of mesenchymatous tissue, which was

well supplied with blood vessels and nerves, both of which entered

thru openings in the cylindrical canal cartilages. The blood vessels

often entered on the dorsal or ventral side, while the nerves entered

thru an opening in the medial side. The central position of the

sensory ridge, the top of the sensory epithelium reaching often to

the center of the canal, was due, not only to the higher cells composing

it, but also to the infolding of the ridge. This infolding was supported

upon the mass of tissue underneath. The ridges terminated quite

abruptly at both ends.

200 HOMER B. LATIMER

Just caudad to each ridge the canal lost its circular outline and

assumed an oval shape, with the long axis perpendicular to the sur-

face. There was in addition a rapid decrease in the size of the lumen,

with a more gradual increase toward the cephalic end of the following

ridge. This was especially noticeable in the tail region, where the

size of the lumen diminished appreciably caudad to each ridge;

in some places the lumen was almost entirely closed. The cylindrical

portion containing the ridge was quite uniform in diameter in the

transverse series but in the longitudinal series it was of considerably

larger diameter in the median portion than at either end. In some

cases the lumen of the “‘drainpipe-cartilages’”’ assumed an elongated

ellipsoidal form. This may have been due to a distortion during the

preparation of the material.

In addition to the differences in the arrangement of the canal

cartilages in the tail region, which has been described above, there

was also a change in the epithelium of the canal itself. In general the

epithelium of the body canal was of the flat pavement type, but in this

region it was cuboidal. The entire lateral canal as well as the lumen

became much smaller and the ridges were not so prominently elevated

into the lumen of the canal. As nearly as could be determined with

the available material there was a difference in the character of the

ridges. In the caudal fin the sensory ridges were composed of deeply

staining, long, narrow cylindrical cells, while in the body region, in

addition to these cells, there was a type of cell less intensely staining

and which often seemed to have its upper end dilated. A group of

these cells would apparently make a little elevation above the rest of

the ridge. The upper end of these cells was often much clearer and

with proper stains it might have been shown to have contained

mucus. These may be the surface mucus cells carried down with

the nervous elements in the formation of the canals as suggested

by Cole (98). Better material and a more careful study of these

conditions would be necessary before a positive statement could be

made.

The height of the epithelium in the various ridges, and the average

height for the three regions of the canal was quite different. The

average height of the sensory epithelium of the ridges of the first region,

or the first thirteen ridges posterior to the gills was .032 mm.; that

of the second region, or from a region about two-thirds of the way

THE LATERAL LINE OF POLYODON SPATHULA 201

back on the side of the body, was .027 mm. and the average height of

several ridges on the dorsal caudal fin was .025 mm. The highest

epithelium, .048 mm. in height, was found in the anterior region,

while the lowest, .020 mm. in height, was found in the posterior

region.

A short distance caudad to the branchlet which originated from

the lateral side of the canal one of the sensory ridges was observed to

commence upon the lateral side of the epithelial canal. Passing

caudad in the series of sections the ridge was observed to pass onto

the dorsal side of the epithelial canal and then almost over to the

medial side. At the point where the ridge left the lateral side and

came to lie more upon the dorsal side of the canal, an exceedingly

fine tube was cut off from the lateral side of the canal, and passing

thru a longitudinal distance of seven sections, or .14 mm., it opened

to the surface. The average diameter of the tube was .02 mm. It

broadened out at its termination on the surface to about .06 mm.

in diameter, and posteriorly it was followed by a slight groove which

gradually became shallower and finally disappeared. In many

respects this tube resembled a branchlet, and very likely may have

been either a developing branchlet or one that was closing, but I am

unable to explain its position. Anterior to this opening the lumen of

the canal was unusually large for the region, being .244 mm. in

diameter. The lumen narrowed down to .112 mm. in diameter in the

cylindrical cartilage immediately following which enclosed the

posterior part of the ridge. The later part of the ridge was normal

both in structure and position. At the caudal end of the cylindrical

cartilage the lumen narrowed as usual, but to a much greater extent,

being only .064 mm. in diameter.

The lateral canal used in this series was divided into seven pieces

for convenience in handling and cutting. The following table will

give the data grouped into seven divisions corresponding to the seven

pieces into which the canal was divided for sectioning. There were

62 branchlets and i51 sensory ridges, or an average of 2.45 ridges for

every branchlet. The first column shows the number of branchlets in

each of the seven divisions, the second, the number of sensory ridges,

the third column, the average length of the ridges in each division,

the fourth and fifth columns show respectively, the longest and the

shortest ridge in each division.

202 HOMER B. LATIMER

Branchlets Ridges Av. Length Longest Shortest

7 14 536 mm. .92 mm 14mm

8 16 470 mm. .62 mm 34 mm

a 20 336 mm. .60 mm 14mm

12 35 293 mm. 78 mm 12 mm

13 35 250 mm. .46 mm 10 mm

3 | 211 mm. 34 mm 12 mm

12 24 290 mm. 52 mm 08 mm

62 151 .3408 mm.

One of the most striking things shown in the table is the decrease

in the average length of the ridges toward the caudal end of the

canal. The table giving the averages for the longitudinal series shows

the same decrease in length. It must be remembered, that the eleven

divisions of the longitudinal series correspond to the first six divisions

of this series, the seventh being the part on the caudal fin which it

was impossible to cut in the longitudinal series. In the above table

there is a gradual decrease in the length of the ridges in the first

six divisions, or that part of the canal lying on the body of the fish,

as the canal approaches the tail, and then a marked increase in the

seventh section or that part of the canal lying on the caudal fin.

In the smaller fish the ridges do not begin to increase in length until

the canal reaches the tail, while in the larger specimen the increase

begins on the posterior part of the body.

The fact that in nearly every instance the ridges terminated so

near the base of the branchlet and extended some distance cephalad

suggested that the sensory ridge or some portion of it might be con-

tinued out into the branchlet. Nothing of the kind had been observed

in either series, but over one-half of the branchlets in the transverse

series were carefully reexamined for the presence of sensory epithelium

in the branchlets. As has been stated before, the ridge occupied the

medial part of the canal extending up slightly, at times, upon the side

of the canal opposite to that from which the branchlet was given off.

The branchlet emerged from the canal from the lateral part of either

the dorsal or ventral sides of the canal and ran nearly parallel to the

surface for some distance. Thus the sensory ridges occupied the

medial half of the canal and the branchlets opened into the lateral

THE LATERAL LINE OF POLYODON SPATHULA 203

half of the canal. The sensory ridge was never seen to divide or

branch. A careful examination of the epithelial lining of the branch-

lets failed to reveal any sensory epithelium. The flat pavement

epithelium of the canal, very soon after entering the branchlet

became more cuboidal, resembling that found in the caudal portion

of the canal. Toward the peripherial ends of the branchlets the

simple cuboidal epithelium gradually became stratified, and passed

over at the tube-pore without any abrupt change into the general

epithelium of the body surface, Only the proximal parts of the

branchlets were enclosed in the cartilaginous rings.

No careful investigation into the nature of the pit organs was

attempted, on account of the conditions of the material and the

thickness of the sections. All of these organs observed in the neigh-

borhood of the canal were encased in a cup-shaped cartilage with a

layer of columnar epithelium across the top of the ‘“‘beaker” or cup-

shaped cavity. Eleven of these pits were observed in the transverse

series.

A rather unusual structure was observed in both series, namely,

the apparent combination of one of the pit organs and a crest of the

lateral canal (fig. 6). Three of these were found in the longitudinal

series and one in the transverse series. The caudal end of the drain-

pipe cartilage where it approached the surface was elongated laterally

forming a cup or “‘beaker-shaped”’ cavity. The rim of this cavity

was on a level with the lower columnar layer of the epidermis and

the bottom was open into the lumen of the cylindrical cartilage.

There was apparently no open communication between the pit organ

and the sensory canal for the opening was covered by quite a thick

membrane. As far as was observed there was no difference in the

structure of these organs and the pit organs which were in no way

connected with the canal. This relation may have no special signi-

ficance but be due to the accidental fusion of the cartilage forming

the cup-shaped cavity with the canal cartilage. The investigation

has not been extensive enough to warrant any conclusions with regard

to these structures.

The location of the nodules, or placoid scale-like structures, pits

and these openings will be shown in the following table as they were

found in the longitudinal series. The grouping into eleven divisions

corresponds to the eleven pieces into which the lateral canal was cut

204 HOMER B. LATIMER

for convenience. The first column gives the number of pit organs

found in the immediate vicinity of the canal, the second column,

the number of “‘openings”’ or combination of pit organ and canal

cartilage, while the third column gives the number of nodules in each

division. Where two or more scales had a common base they were

counted as one. The last column gives the number of crests in each

division which had no surface marking; neither pits, “openings,”

nor nodules. The table shows very clearly the anterior position of the

pits and the “‘free crests,” and the posterior location of the nodules.

Pits Openings Nodules “Free crests”

2 2 2 10

1 0 6 3

2 0 6 A

1 0 5 4

2 0 8 3

1 0 11 4

1 1 13 1

0 0 12 1

0 0 11 2

0 0 7 0

os)

ioe)

IV. SUMMARY

1. As the lateral canal passes caudad from the gill region its

diameter gradually becomes smaller.

2. The sensory ridges are located upon crests or parts of the canal

approaching the surface. The lumen of the canal here is always

larger than just anterior or posterior to the ridge.

3. The longest ridges are in the anterior region. There is a

gradual diminution in length going caudad upon the body until just

before the tail is reached, or upon the tail itself, where there is a slight

increase in length.

4. No branchlet, except on the caudal fin where there seems to be

a great irreguarity, is given off without a sensory ridge at its proximal

end. Ridges may or may not occur between the branchlets.

THE LATERAL LINE OF POLYODON SPATHULA 205

5. The branchlets tho grouped to a slight extent are given off

thruout the entire length of the lateral canal.

Department of Zoology,

University of Nebraska.

V. BIBLIOGRAPHY

Auiis, E. P.

1889. The anatomy and development of the lateral line system in Amia calva-

Jour. Morph., Vol. 6.

1899. A reply to certain of Cole’s criticisms of my work on Amia calva. Anat.

Anz., Bd. 15.

1900. The lateral sensory canals of Polypterus. Anat. Anz., Bd. 17.

1903. On certain features of the lateral canals and cranial bones of Polyodon

folium. Zool. Jahrb.

BALFour, F. M.

1881. Comparative embryology. Vol. 2.

BEARD, John.

1884. On the segmental sense organs of the lateral line and on the morphology

of the vertebrate auditory organ. Zool. Anz., Bd. 7.

1885. On the cranial ganglia and segmental sense organs of fishes. Zool. Anz.

Bd. 8.

BrEcKwitTH, Miss Cora, J.

1907. The early development of the lateral line system of Amia calva. Biol. Bull.

BROHMER, VON P.

1908. Die Sinneskanale und die Lorenzinischen Ampullen bei Spinax Embryonen.

Anat. Anz.

Crapp, Miss Cornea M.

1898. The lateral line system of Batrachus tau. Jour. Morph. Vol.15.

Cote, F. J.

1898. On the structure and morphology of the cranial nerves and lateral sense

organs of fishes.

CoLiince, W. E.

1894. The sensory canal system of fishes. Q.J.M.S. Vol. 36.

1895. On the sensory canal system of fishes. Proc. Zool. Soc. London.

HERRICK, C. Jupson,

1903. On the morphology and physiological classification of the cutaneous sense

organs of fishes. Amer. Nat. Vol. 37.

1903. On the phylogeny and morphological position of the terminal buds of

fishes. Jour. Comp. Neur. Vol. 13.

Jounson, S. E.

1917. The structure and development of the sense organs of the lateral canal

system of Selachians (Mustelus canis and Squalus acanthias). Jour.

Comp. Neur. Vol. 28.

206 HOMER B. LATIMER

KLINKHARDT, W.

1905. Bietrage zur Entwickelungsgeschichte der Kopfganglien und Sinneslinien

des Selachier. Jen. Zeitschr.

LEE, F. S.

1898. The function of the ear and the lateral line in fishes. Am. Jour. Phy.

Vol. 1.

Leypic, FRANz,

1850. Ueber die Schleimkanale der Knockenfische. Arch. f. Anat. und Phy.

1857. Lehrbuch der Histologie des Menchen und der Thiere.

1868. Ueber Organe eines Sechsten Sinnes.

M’DonnNeEL, ROBERT,

1862. On the system of the lateral line in fishes. Trans. Royal Irish Acad.

Vol. 24.

Parker, G. H.

1902. Hearing and allied senses in fishes. Bull. U.S.F.C. Vol. 22.

1903. The sense of hearing in fishes. Am. Nat. Vol. 17.

1904. The function of the lateral line organ in fishes. Bull. U.S. Bureau of

Fisheries. Vol. 24.

Porarp, H. B.

1892. The lateral line system in Siluroids. Zool. Jahr. Bd. 5.

SCHULZE, FRANZ E.

1861. Ueber die Nervenendigung in den sogenannten Schleimkanalen der

Fische und uber entsprechende organe der durch Kiemen athmenden

Amphibien. Arch. f. Anat. u. Phy.

STAHR, HERMAN,

1897. Zur Funktion der Seitenorgane. Biol. Centralblatt Bd. 5.

Voert, C.

1856. Ueber die Schleimkanale der Fische. Zeit. f. Wiss. Zool. Bd. 7.

Wricat, R. R.

1884. On the skin and cutaneous sense organs of Amiurus. Proc. Canad. Inst.

Vol. 2.

1884. Nervous system and sense organs of Amiurus. Proc. Canad. Inst. Vol. 2.

(CAN MICROSCOPICAL

YXVIII

TRANSACTIONS OF

SOCIET

V indicates pla!

X posterior to

ler Fish.

vut.

es were not indicated

THE LATERAL LINE OF POLYODON SPATHULA 207

EXPLANATION OF PLATES XVIII and XIX

Fig. 1. Diagram of the right lateral line from the smaller fish.

Fig. 2. Diagram of the right lateral line from the larger fish.

Fig. 3. A crest from the longitudinal series showing an ‘‘opening.” Outlined with

camera lucida. Zeiss objective A, ocular no. 4.

Fig. 4. A crest from the longitudinal series showing the cylindrical cartilage projecting

above the surface as a nodule (c.n.) Magnification as for fig. 3.

Fig. 5. A section from the longitudinal series showing a crest in sagittal section and a

free nodule (n). Same magnification as fig. 3.

Fig. 6. A section from the transverse series showing an “opening.” Outlined with

camera lucida Zeiss objective D, ocular no. 2.

Fig. 7. Section from the transverse series showing a pit organ (f.p.) and passing thru

the anterior part of a branchlet (br.), showing the continuation of the canal

cartilage out around the branchlet. Drawn with the same magnification as fig. 6.

X=posterior to this point the nodules were not indicated.

V indicates places where line was cut.

b ring-shaped canal cartilages. pt pit organ attached to the cylindrical

cartilage.

br base of branchlet n free nodule

c cylindrical canal cartilage 0 opening for the entrance of nerve

cn nodule attached to the cylindrical car-

tilage p pigment cells

e surface epithelium y sensory ridge

f p free pit organ

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

PLATE XIX LATIMER

A NEW TREMATODE, ACANTHATRIUM NYCTERIDIS,

NOV. GEN., NOV. SPEC., FROM THE LITTLE

BROWN BAT:.'

By Ernest CARROLL Faust

The material described in this paper was taken from the small

intestine of a female Nycteris borealis-borealis (Miller). The bat was

found in the vicinity of Urbana, Illinois and brought to the writer

during the summer of 1918. With the female were two suckling

young which were uninfected. Of the ten individuals of the new

parasite found, two were studied alive and the remainder preserved

and studied as totos and sectioned material. In the living specimens

the details of the excretory system were worked out and the process

of fertilization observed.

This species conforms to the previous diagnostic rules prescribed

for the genus Lecithodendrium in the shortness of the digestive ceca,

the position of the uterine loops, the general type and position of the

testes and vitellaria and in the absence of a muscular cirrus. However

since the structure of the organs immediately surrounding the genital

pore are important criteria on which generic diagnosis is made, it

seems necessary to create a new genus to include this species and

Lecithodendrium sphaerula Looss 1896, which possess in common a

genital atrium lined with numerous lanceolate spines. I propose the

name Acanthatrium for this new genus.

Diagnosis of Acanthatrium nov. gen. Small-sized Brachycoeliinae,

spherical to pyriform, with a genital atrium lined with numerous

integumentary spines; prostate glands numerous; testes preacetabu-

lar, in a plane with the genital pore; vitellaria anterior to the digestive

ceca; excretory system with four groups of flame cells of three each for

each half of the body; in intestine of bats. Type species: A. mycter-

idis.

1 Contributions from the Zoological Laboratory of the University of Illinois,

No. 138, and from the Department of Pathology, Peking Union Medical College.

209

210 ERNEST CARROLL FAUST

Acanthatrium nycteridis nov. gen., nov. spec.

Host: Nycteris borealis-borealis (Miller), small intestine

Locality: Urbana, Illinois

Date: July, 1918

Acanthatrium nycteridis is a broadly oval to pyriform fluke which

normally measures 0.185 to 0.2 mm. in length by 0.15 to 0.16 mm. in

width, but on contraction may become much broader or longer. All

specimens examined have been found to be spineless on the external

integument. The oral sucker measures up to 25 » in diameter and is

AIM,

Text fig. 1. The excretory system of Acanthatrium nycteridis.

consequently much larger than the acetabulum which always mea-

sures less than 16y. ‘The latter organ is situated some two-fifths

distance from the anterior end of the fluke. The oral opening leads

directly into a very muscular pharynx, 6 in diameter by 4-5 w in

ACANTHATRIUM NYCTERIDIS, NOV. GEN., NOV. SPEC. 211

length. The ceca compose a short broad furculum lying between the

vitelline glands on the anterior face and the prostate glands on the

posterior face. They extend laterad as far as the testes. The walls

of the ceca are heavy, and the cells of which they are composed

distinctly glandular.

The excretory system of this species has been studied very care-

fully in the living animal subjected to slight pressure of the cover

glass. Not only have the main canals of the system been made out

but the exact number and relationship of the capillaries and flame

cells have been determined. ‘These latter comprise four triplet

groups for each side of the body, making a total of twenty-four cells

for the worm. The excretory pore is posterior. It leads into a single

muscular shank of short length (see text fig.) which soon expands into

two long pouch-like cornua. These cornua extend anteriad to a plane

somewhat back of the middle of the body. There each cornu receives

a single very short main collecting tubule. Into this main tubule flow

two secondary tubules, one of which is derived from a double set of

three capillaries each lateral and posterior to the main tubule and a

second which is derived from a double set of three capillaries each

arising anteriad and somewhat mesad. At the end of each capillary

is a small flame cell. Designated from the anterior end backward

(Faust 1919) group a’ lies ventrad to the median frontal plane of

the fluke, laterad and slightly posteriad to the oral sucker. Group

p’ also lies ventrad, but laterad to the prostate glands. Group

a” lies dorsad, in the region just posterior to the acetabulum. Group

p” lies ventrad to the cornu on each side. A view of the individual

flame cell under the highest powers of the microscope shows the

“flame” to consist of a relatively small number of flagella which are

noticeably thick at their distal ends. No excretory granules appear

in the system.

Previous studies on the excretory system of the Brachycoeliinae

(Looss 1896: Fig. 50) are fragmentary, but are consistent with the

data I have secured from the study of the species Acanthatrium

nycteridis, namely, that there is a common flame-cell plan for the

Brachycoeliinae. On the basis of this scheme it is expected that there

will be found in each species of the sub-family twenty-four flame cells,

consisting of four triplet groups of flame cells on each side of the

body. Furthermore, the work of Wright (1912:167-169) on the

PAD ERNEST CARROLL FAUST

related family Microphallinae gives weight to the view that there is

a fundamental plan of flame-cell grouping in the family. For, in

Microphallus opacus altho there are only sixteen flame cells in the

adult worm, they consist of four couplet groups for each side of the

body, so that the four groups are to be regarded as elemental, hence

fundamental. Moreover, the rather inadequate study of Jager-

skidlId (1900) on the excretory system of Spelotrema pygmaeum

demonstrates at least the fourfold structure in this species. Thus as

I have remarked (1919) ‘“‘the mathematical exactness of flame-cell

formation of this family makes it possible to calculate the flame-cell

formula of the cercaria from the structure of this system in the adult.”

The genital system in Acanthatrium nycteridis is characteristically

lecithodendrine. The ootype is located to the right and somewhat

posterior to the acetabulum. The vitelline follicles, ten to twelve in

number, lie lateral to the pharynx and esophagus and anterior to

the ceca. They are somewhat lobed. Two vitelline ducts, dark

brown in color, arise from the two groups of follicles. Extending

over the ceca and prostate glands, they bend toward the median line

and converge behind the acetabulum. From this junction a common

vitelline duct proceeds to the ootype. The ovary is an irregular

pyriform body, somewhat smaller than the testes and located anterior

to the ootype, in the plane of the acetabulum. It is connected with

the ootype by a short duct. A minute seminal receptacle opens into

the ootype from the right side. From the side of this receptacle a

delicate Laurer’s canal extends toward the integument of the dorsal

side of the worm. The uterus arises from the posterior side of the

ootype. Its convolutions first fill the posterior half of the right side of

the fluke, then turn to the left side, crowding the entire region up

to and often encroaching upon the left testis. The uterus enters the

genital atrium to the left of the ejaculatory duct.

The testes are ovoid to pyriform glands occupying the same

transverse plane as the genital pore and the surrounding prostate

glands. They are definitely antacetabular. Vasa efferentia carry

the spermatozoa mesad to the base of the seminal vesicle on the anter-

ior border of the acetabulum. The latter organ coils to the left and

then forward. It passes almost imperceptibly into the short ejacu-

latory duct. This duct opens into the genital atrium thru a small

pore. The prostate glands surrounding the metraterm and opening

ACANTHATRIUM NYCTERIDIS, NOV. GEN., NOV. SPEC. 213

into the ejaculatory duct consist of a large spherical mass of unicel-

lular glands.

The genital atrium lies mostly anterior to the genital pore. It

is elongate and coiled on itself several times, and is lined with a large

number of sharp lanceolate spines. The genital pore is large with a

prominent sphincter muscle.

The mature uterus is filled with fertilized eggs. They have a

distinct operculum at one end, are oval, and are light brown in color.

They measure 33 by 19 at the inner end of the uterus and 44 by 23

at the opening of the uterus into the genital atrium. In spite of the

crowding of the uterus with eggs spermatozoa were observed to pass

in large numbers from the genital atrium down the uterus to the

ootype. The activity of these sperm frequently caused the eggs to

back up into the ootype and even into the distal end of Laurer’s

canal. At times the sperm masses occupy half of the uterus.

Fertilization occurs in the ootype. The naked protoplast comes

down the oviduct at irregular intervals. Material from the common

vitelline duct is then laid around the ovum, after which the shell is

added.

DISCUSSION

The Brachycoeliinae as originally constituted by Looss (1899 :608)

have come to include Brachycoelium, Pycnoporus, Phaneropsolus,

and Lecithodendrium. To this group must now be added the new

genus Acanthatrium, previously embodied in part in Lecithoden-

drium. European investigators have divided this group into two

parts, one consisting of those genera in which a muscular cirrus pouch

is present and one containing those genera where a cirrus bulb is

wanting, or, at most, parenchymatous in structure. Liithe (1901:173)

and Looss (1902:815) have even suggested that those genera including

forms without muscular cirrus should be withdrawn from the Brachy-

coeliinae and placed in a new subfamily, the Lecithodendriinae.

The genus Acanthatrium readily falls into the latter group, because

species of this genus lack any evidence of muscular structure in the

region of the ejaculatory duct.

An examination of the various species comprehended up to this

time under the head Lecithodendrium shows that exact data on the

seminal receptacle are lacking in many species. Moreover the out-

214 ERNEST CARROLL FAUST

line of the ovary is decidedly varied, being entire in certain species

and decidedly lobed or sinuate in closely related ones. But the posi-

tion and type of the vitellaria and of the testes, and the presence or

absence of spines in the genital atrium give a basis for a natural divi-

sion of these species into three groups. The first group contains those

in which the genital atrium is lined with conspicuous spines and in

which the testes are antacetabular in a plane with the genital pore.

These species, mycteridis nov. spec., and sphaerula Looss belong to

the genus Acanthatrium. The second group consists of those species

in which the genital atrium is aspinose, in which the vitellaria are

lateral to the pharynx, but in which the testes are in the plane of

the acetabulum. To this group belong the species ascidia van

Beneden, chefrenianum Looss, chilostomum Mebhlis, cordtforme

Braun, glandulosum Looss, obtusum Looss, posticum Stafford,

and pyramidum Looss. These species belong to the genus

Lecithodendrium sensu stricto. The third group contains species,

which, like those just mentioned, have an aspinose genital atrium

and testes in the plane of the acetabulum, but in which vitellaria

are conspicuously posterior to the ceca and near to the acetabulum.

To this group belong the species granulosum Looss, hirsutum Looss,

and urna Looss, and for them I propose on the basis of this distinction

a new genus, Mesodendrium. Other species at one time or another

referred to Lecithodendrium have either been removed from this genus

or are so inadequately described that their exact position can not be

fixed with certainty.

SUMMARY

1. Acanthairium nycteridis nov. gen., nov. spec., from Nycteris

borealis-borealts is described.

2. The excretory system of this species is based on a fundamental

four-fold grouping of triplet flame cells, which, by comparison, sug-

gest that the four-fold grouping is a common denominator of the

several sub-families of the Brachycoeliidae.

3. Analysis of the species of Lecithodendrium sensu lafo makes it

necessary to recognize three genera from this group, Acanthatrium

nov. gen., Lecithodendrium sensu stricto, and Mesodendrium nov. gen.

ACANTHATRIUM NYCTERIDIS, NOV. GEN., NOV. SPEC. 215

EXPLANATION OF PLATE

Dorsal view of Acanthatrium nycteridis, showing reproductive organs. X 340.

REFERENCES CITED

Faust, E. C.

1919. The Excretory System in Digenea. II. Observations on the Excretory

System in Distome Cercariae. Biol. Bull.

JAGERSKIOLD, L. A.

1900. Levinsenia (Distomum) pygmaea Levinsen, ein genitalnapftragendes

Distomum. Centralbl. Bakt. Parasit., 37: 732-740, 3 t. figs.

Looss, A.

1896. Faune Parasitaire de l’Egypte. Premiére Partie. Mem. Inst. Egypt.,

3:1-250, 16 pl.

1899. Weitere Beitrige zur Kenntniss der Trematoden-Fauna Aegyptens.

Zool. Jahrb. Syst., 12: 521-784, 8 pl.

1902. Ueber neue und bekannte Trematoden aus Seeschildkréten. Zool. Jahrb.

Syst., 16: 411-894, 11 pl.

Liner, M.

1901. Zwei neue Distomen aus indischen Anuren. Centralbl. Bakt. Parasit.,

30: 166-177.

WRIGHT, S.

1912. Notes on the Anatomy of the Trematode, Microphallus Opacus. Trans.

Am. Micr. Soc., 31: 167-175, 2 pl.

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PLATE XX FAUST

THE PRESERVATION OF FRESH-WATER BRYOZOA

By F. SLATER Jackson, M.D.

The following method is the outcome of a series of experiments

made by the writer during the summer of 1916, while engaged in a

preliminary study of the fauna of certain of the Laurentian lakes in

Argenteuil County.

Attempts were made to preserve several species of Bryozoa in an

expanded condition by treating specimens (previously narcotized with

chloretone, cocain, chloral hydrate, etc.) with alcohols of grad ually

increasing concentration, formalin and other reagents, but without

success. Nor did the sudden killing and fixation of small colonies by

means of well-known reagents, such as hot corrosive-acetic, chrom-

acetic, osmic acid mixtures or Bouin’s fluid, give better results.

For reasons afterwards to be discussed, the following method

suggested itself to the writer, and has afforded good results for several

species.

(1) Narcotization. Elongated colonies attached to twigs or to

the stems of aquatic plants, are placed in water in a tube of convenient

length, and of a diameter sufficient to permit of the colony lying

obliquely, so that it may not come in contact with the tube except

at the extremities. In the case of flattened forms, e.g., those occurring

on leaves, etc., the operations are best conducted in Petri dishes. A

saturated aqueous solution of cocain* is slowly added by means of

a pipette. At first a small quantity of the solution (say 1 c.c.) is

dropped upon the surface of the water and allowed to diffuse. A

similar amount may be added at intervals of five minutes, a small

quantity of the water being removed from time to time if necessary.

The retraction of the zooids caused by the first addition of the

cocain is only temporary, and uniform expansion of the whole colony

will be attained in about half an hour.

* A saturated aqueous solution of chloretone may be substituted, of which, how

ever, a larger quantity will be required.

217

218 F. SLATER JACKSON

When this stage is reached, about 5% of the entire fluid may be

withdrawn, and replaced by the cocain solution, which is to be forcibly

injected into the remaining fluid by means of the pipette, in order to

ensure its uniform admixture.

After this time the colony should be observed at intervals with a

lens, and if ciliary motion has ceased (as indicated by the cessation of

vortices containing fecal and other particles) no further addition of

cocain is necessary.

Periodical stimulation (either by touching the individual extended

lophophores with a needle, or, preferably, by setting up currents with

the pipette) will indicate the degree of narcotization. This will

probably be complete in from one to one and a half hours, but will

vary with the species.

In every case tt will be advisable to wait for ten minutes after there is

no further response to stimuli, before adding the preserving fluid, other-

wise immediate and permanent retraction may follow its addition.

(2) Preservation. The tube or dish containing the narcotized

colony is placed in a convenient vessel (to permit of overflow) and the

narcotizing fluid gradually replaced by a fluid having the following

composition :—

Cane sugar 10 parts

Formalin 2 parts

Distilled water to 100 parts

(The sugar is to be dissolved in the water and the formalin subse-

quently added.)

The replacement is made by injecting the preserving fluid (a

pipetteful at a time) with sufficient force to ensure its admixture with

the narcotizing fluid, and its uniform contact with the colony. When

it is estimated that the fluid consists of approximately 50% of the

sugar solution, the preparation may be allowed to remain in this for

about half an hour. At the expiration of that time the preserving

fluid may be added more rapidly until it almost completely replaces

the former mixture. The colony is then left undisturbed for half an

hour or more, and may then be transferred to a fresh vessel containing

the undiluted preserving fluid.

The time required for the entire process, from the commencement

of narcotization, is about 21% hours, but will be found to vary slightly

for different species.

PRESERVATION OF FRESH-WATER BRYOZOA 219

Numerous preparations of Plumatella, Fredericella and Cristatella,

made according to this method in August, 1916 are still in an excellent

state of preservation.

It is suggested that the fluid be changed after the lapse of a week

or ten days.

While not primarily designed as a microscopic or histological

method, the above treatment has been found to afford an adequate

means of preliminary preservation for material to be subsequently

employed in the preparation of slides, or even of sections.

For this purpose individual zooids or small portions of the colony

are to be dropped into Bouin’s fluid,* allowed to remain in this for a

few hours, and then transferred to 70% alcohol.

When free from picric acid they may be stained 7m toto and

mounted, or embedded in paraffin in the usual way.

It has been found that the tissues, and even the cilia, are well

preserved.

The formalin-sugar solution has, with modifications, been success-

fully employed for the preservation of insect larve and pupe,' and

may also be used for various small invertebrates.

A consideration of some aspects of the question of the permeability

of cell-membranes, and of the adsorption phenomena of cane sugar,

suggested the possibility of the application of a solution such as the

above in the preservation of Bryozoa. Since the surface tension at

the interface between water and other phases is but slightly reduced

by sugar, and, as has been pointed out by Michaelis and Roona,’

and by Parkin,’ adsorption of sugar does take place at such surfaces,

the employment of a sugar solution offers possibilities for the preserva-

tion of delicate tissues. The observations of Kiister* on the cells of

the onion, plasmolyzed by hypertonic sugar solution, seem to indicate

that there is a certain degree of fixation of the surface membrane.

’ Furthermore in view of the fact that, as established by Freund-

lich,> gelatin will adsorb sugar only after preliminary treatment with

formalin, and since the experiments of Lloyd® have indicated the

essential similarity of protoplasm and gelatin as regards their behav-

ior in imbibition and similar phenomena, it was thought that the

*Picric acid, saturated aqueous solution........ 75

lorrinabinne si.) viedo tae east aie Metered 20

220 F. SLATER JACKSON

employment of sugar and formalin in combination might provide an

efficient preservative for these organisms.

It is suggested that the efficacy of the method is due to the fixation

of the protoplasm by the formalin, and to the protective action of

the adsorbed sugar.

The employment of formalin alone as a preservative, although

recommended by Green’ and by Davenport,* has, in the writer’s

hands, invariably proved fatal.

As is well known, formalin combines chemically with proteins,

and in the case of fresh-water Bryozoa, it results in the formation of

a flocculent precipitate, and the ultimate separation and disintegration

of the lophophores. Similarly, while one of the best preservatives

for marine Ccelenterates, it gives poor results with Hydra. On the

other hand, it proves excellent for the free-swimming larve of Bryo-

zoa, and for statoblasts.

Zoological Laboratory, McGill University,

June 10th, 1919.

LITERATURE CITED

Jackson, F. SLATER

(1) 1919. “A method for the preservation of Insect Larvae and Pupae.”’ Can.

Entomologist. Vol. 51, No. 5. May 1919, pp. 117-118.

Micwaetis, L. and Roona P.

(2) 1909. “Adsorption des Zuckers”’ Bioch. Zs. Bd. 16, pp. 489-498.

PARK, J.

(3) 1911. “Carbohydrates of the Foliage Leaf of the Snowdrop.” Bioch. Jl.,

Vol. 6, pp. 1-47.

Kuster, E.

(4) 1909. “Ueber die Verschmelzung nacter Protoplasten” Ber. Deutsch. Bot.

Ges., Bd. 27, pp. 589-598.

FREUNDLICH, H.

(5) 1909. “Kapillarchemie.”

Lioyp, FRANcIs, E.

(6) 1917. “The Colloidal properties of Protoplasm: Imbibition in relation to

growth” Trans. Royal] Soc. Canada, Sect. 4, 1917, p. 139.

GREEN, BESSIE R.

(7) 1914. “Preservation of Bryozoa’”’ Trans. Amer. Micros. Soc. Vol. 33, No. 1,

Jan. 1914, pp. 55-56.

DAvVENpPoRT, C. B.

(8) 1918. (in Ward and Whipple’s ‘“‘Fresh-water Biology,” p. 951.

For the accompanying photographs, I am indebted to Mr. W. B. Stokes, Secretary

of the Montreal Natural History Society. Plate XXI is Cristatella mucedo and

Plate XXII is Fredericella sp.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

PLATE XXI JACKSON

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XX XVIII

PLATE XXII JACKSON

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SOME EXPERIMENTS CONDUCTED WITH PURE

CULTURES OF BREAD YEAST

By Wr11AM F. HENDERSON

Study of the conditions under which yeast colonies most rapidly

develop, also of the conditions under which yeast produces carbon

dioxide, have always been very interesting as well as practical. The

failure to secure satisfactory yeast growths and gas productions when

ordinary bacteriological media were used, led the author to pursue

the problem more in detail, with the discovery of some very interest-

ing facts concerning yeast development.

ISOLATION OF THE YEAST COLONIES

Some pieces of ““Yeast Foam” were mixed with distilled water.

Agar and gelatin plates were made from diluted portions of this

stock solution and the agar plates were incubated at 38° C. The

gelatin plates were allowed to develop at room temperature, 20° C.

The yeast colonies developed on the agar plate along with bacterial

colonies, but none of the yeast colonies grew very large. The largest

was not quite one mm. in diameter, circular, soft, and dull gray.

The colonies on gelatin developed much more slowly and were no

larger than those on agar.

Sub-cultures were made in sloped agar tubes. The maximum

development gave a very thin streak of circular colonies, closely

packed together. The development was scanty and far from satis-

factory. Microscopical mounts were made from one of these streak

cultures and no organisms were found to be present save the yeast.

This pure culture was saved and was used as the source of material

directly or indirectly, for all later experiments.

EXPERIMENTS ON SOLID MEDIA

The familiar relationship which exists between yeasts and sugar

fermentation at once suggested the addition of sugar to the agar

medium. This was tried as follows:

Author’s Note: During the course of these experiments many helpful suggestions

were made by Dr. A. A. Tyler to whom the author wishes to express his appreciation.

KC o2e

222 WILLIAM F. HENDERSON

Small amounts of cane sugar, lactose, and glucose were added,

respectively, to three agar tubes. These tubes were sterilized and

cooled in a sloping position, and when cold, were innoculated from

pure yeast cultures. The material was incubated for 24 hours at

38° C. and the results noted. The cultures on cane sugar agar and on

lactose agar had scarcely developed at all; only thin, transparent

streaks were visible. The yeast on glucose agar, however, had grown

so rapidly that the entire surface of the medium was covered with the

thick creamy-white mass of colonies. Upon microscopical examina-

tion, this material on glucose agar proved to be pure yeast culture.

It would seem then, that the monosaccharides, of which glucose is

an example, furnish much more favorable conditions for yeast

development than do the disaccharides.

Further experiments were performed, using a larger variety of

sugars. Seven agar tubes were prepared, six of which contained the

following sugars, respectively:

Monosaccharides: Disaccharides:

Glucose Saccharose (cane sugar)

Galactose Maltose

Levulose Lactose

The seventh tube was used without sugar and served as a check.

One cc. of sterile water was poured into each of seven Petri dishes

which had previously been sterilized. This water was innoculated

with a small amount of yeast material and the plates poured in the

usual manner, using the seven tubes of agar described above. These

plates were incubated at 38° C for 28 hours. Development on two of

the monosaccharides (glucose and levulose) was very rapid, while on

the galactose and on the disaccharides, development was slight.

Of the disaccharides, cane sugar seemed to furnish the most favorable

conditions. The largest colonies on the glucose and levulose agar

plates were surface colonies 6 to 7 mm. in diameter. The largest

colonies on any of the other plates were 2 to 3 mm. in diameter.

These occurred on the cane sugar plate and were surface colonies.

The accompanying illustration shows the results obtained on these

plate cultures. The plate containing galactose agar was not included

in the photograph as it was identical in appearance with No. 6 (agar

without sugar). It seems, therefore, that galactose, maltose, and

lactose contribute very little, if any, to the conditions favorable for

EXPERIMENTS WITH CULTURES OF BREAD YEAST 223

yeast development on solid media; that cane sugar improves the

conditions slightly, and that glucose and levulose produce conditions

exceedingly favorable for yeast growth.

VARIATIONS IN MORPHOLOGY

When yeast grows in liquid media, the cells produced are of the

familiar form viz., round, or more often, oval. As the budding occurs,

small round or oval cells are produced, and these break off very

readily, especially if the medium is agitated by shaking or stirring.

In the case of the yeast used in these experiments, the maximum

diameter attained by the cells in liquid media was from 7 to 9 microns.

It is evident at the outset, that the conditions encountered by the

yeast in or on a solid medium were entirely different from those

encountered in a liquid medium. A careful examination of the plate

cultures described previously showed that while the colonies wer

still minute, those on the surface, as well as those below the surface

of the agar, were composed of cells identical in appearance with

yeast cells grown in liquid media. As the colonies became older and

larger, those on the surface retained their generally circular form,

composed of ordinary oval yeast cells closely packed together. At

the edge, the layer was one cell thick, but in the center budding had

occurred vertically, thus rendering the colonies more or less opaque.

Cells in all stages of budding could be seen, as the solidity of the

medium held all the cells and buds in their respective positions.

As the deep, embedded colonies grew older, they attained a dis-

tinctly stellate appearance. These colonies possessed a small circular

“nucleus” of ordinary oval yeast cells, but at the edge, some of the

cells had become greatly elongated, growing in a direction away from

the mass of the colony. Repeated budding and elongation of cells,

together with the solidity of the medium resulted in the formation of

long branched filaments, extending radially from the central colony.

When cells from these stellate colonies were transferred to a slide

and examined, it was found that the cells had all broken apart in the

transfer. The cells observed were almost all single, some being oval

in shape and others very long and slender. It is evident then, that

the solidity of the medium (causing the cells to be immovable in

reference to each other) was the cause of the filamentous formation.

Furthermore, as the initial cells of the colony grew and multiplied,

224 WILLIAM F. HENDERSON

a paucity of food would soon arise in the immediate vicinity. In

liquid media, diffusion would maintain the supply of food for a con-

siderable length of time, but in a solid medium diffusion would be

slow. ;

As the young colony grew and spread in all directions, the food

supply in the medium within the colony soon became almost

exhausted. Very soon, those cells at the edge received the food

stimulus only from the medium outside the colony. They responded

to this more localized stimulus by growing and budding in a direction

away from the mass of the colony. The location of the cell contents

proved also to be interesting. The older, elongated cells were highly

vacuolated. The younger, elongated cells (farther away from the

mass of the colony) were less vacuolated. The vacuoles appeared

first in the older part of the cell (nearer the mass of the colony) and

the cell protoplasm tended to collect in the end of the cell away from

the mass of the colony. Finally, the terminal cell contained only a

few very small vacuoles and in many cases was found to be budding

at the free end. The occurrence of more than one bud resulted in the

formation of a “branch” in the filament. The accompanying figures

show some of the types of filamentous growths and elongated cells.

EXPERIMENTS ON GAS FORMATION

A Smith gas tube was filled with 1% lactose bouillon and innocu-

lated with pure yeast. Development occurred in the open arm only

and no gas was registered in the tube. This suggested the thought

perhaps the yeast was aerobic in character and would not develop to

any extent under anaerobic conditions.

Gas tubes were prepared with two-hole cork stoppers; through

one hole was placed a glass tube drawn out to a fine capillary and

reaching to the bottom of the gas tube. Through the other hole was

placed a short glass tube to allow exchange of gases as changes of

pressure required. Both tubes were bent down outside and plugged

with cotton. The gas tubes were filled with sugar bouillon, corked,

and sterilized. The tubes were carefully innoculated with pure yeast

and then from 30% to 40% of sterile oxygen forced into the closed

arm through the capillary. A check tube was prepared in which no

gas was admitted. These tubes were incubated 120 hours after

which time no further changes seemed to occur. The residual gas in

EXPERIMENTS WITH CULTURES OF BREAD YEAST 225

the tubes was tested for carbon dioxide by absorption in 5% potas-

sium hydroxide solution. The results were as follows:

4 Initial Final % Absorbed Residual

eSLE Gas Gas by KOH Gas

Bouillon+ Oxygen 8% 5% 3%

1% Cane Sugar 38%

Bouillon+ Oxygen 6% 3% 3%

1% Lactose 34%

Bouillon+ Oxygen 8% 0% 8%

1% Glucose 35%

Bouillon+- Air 27% 3% 24%

1% Lactose 32%

Bouillon+- No Gas No Gas a ==

eee RCEOBEN Wm UL Testicle mnimecnee a Wh hea Lactose

Where oxygen or air was admitted, development occurred in both

arms of the tubes. In the last tube where no gas was admitted,

development occurred in the open arm only. These tests strongly

suggest that the yeast used (ordinary bread yeast), is aerobic. This

conclusion is supported by the fact that in the agar plates described

earlier, the deep colonies never attained any great size while the sur-

face colonies grew (when on suitable media) to a large size.

According to chemical laws of gases, one volume of oxygen will

produce the same volume of carbon dioxide. However, when we

consider that carbon dioxide is 25 or 30 times as soluble in water as

is oxygen, the shrinkage of gas volumes in the tubes is easily ex-

plained. As the slightly soluble oxygen was replaced by carbon diox-

ide, this latter gas would remain dissolved in the water and the

liquid would rise to replace the oxygen used. This could proceed

until the liquid became practically saturated with carbon dioxide.

The proof of this explanation lay in the following simple test: A gas

tube was filled with distilled water and 33% of carbon dioxide passed

into the closed arm. This tube was placed in the incubator over

night. In twelve hours all but 3% of the gas had been absorbed.

Even though the liquid might become saturated and an excess of gas

226 WILLIAM F. HENDERSON

be produced by some organism, the slow diffusion and escape through

the open arm of the tube would result in a gradual shrinkage of gas

volume. This was shown by placing 35% of carbon dioxide over

water previously saturated with the gas. In thirteen days the gas

volume read 15%.

The last experiment performed consisted of the innoculation of

gas tubes which contained different percentages of several kinds of

sugars. The sugars used were glucose, lactose, cane sugar, and mal-

tose. The percentages used were 1%, 5%, and 10% in each case

except maltose, where 1% and 5% were used. No air nor oxygen

was passed into the closed arms. All the tubes were incubated at

38° C. Those containing lactose and maltose developed a very

slight scum over the surface of the liquid in the open arm. The liquid

in the closed arm remained perfectly clear and no gas was registered.

The tubes containing 1% and 5% cane sugar developed fairly well

in the open arm, but not at all in the closed arm. Where 10% cane

sugar was used, 14% of gas appeared on the sixth day. The maximum

percentage in this tube was 1%, acquired on the seventh day. There

was an excellent development in the open arm and a fair develop-

ment (cloudiness) in the closed arm.

The tubes containing glucose developed without delay. Scum

formed on the surface of the liquids in a few hours. A record of the

gas formation follows:

Medium | 42 45 50 53 56 66 70 74 117 130 .

Used hrs. hrs. hrs. hrs. hrs. hrs. hrs. hrs. hrs. hrs.

1% Glu-

ose 3% | 5% | 14% | 30% | 48% | 77%) 88%} 90% | 30% | 20%

5% Glu-

ros Sa | ea 2% | 4% | 20% | 42% | 100% | 100% | 100% | 63% | 63%

10% Glu-

ose pean Os ete acs MCE CLE, RU 9% | 100% | 100% | 100% | 100% | 100%

At 100% the gas overflowed and bubbled out through the open

arm. In the tube containing 5% glucose, a shrinkage from 100%

(full) to 63% occurred, at which time evaporation of the liquid

allowed air to bubble in and stop the shrinkage. The tube containing

10% glucose remained full of gas as long as observations were taken.

EXPERIMENTS WITH CULTURES OF BREAD YEAST 227

Food became nearly exhausted first in the tube containing 1% glu-

cose. Diffusion and consequent loss of carbon dioxide caused shrink-

age to begin first in this tube. The food in the 5% glucose tube

became scarce a few hours later and shrinkage began at once. Food

in the 10% glucose tube evidently was still available at the time of

the last observation.

When these results are compared with those obtained from the

plate cultures, we find admirable agreement. The glucose (as would

probably levulose) gave very favorable conditions for quick growth

and rapid gas formation. Of the disaccharides, cane sugar was the

most suitable, but did not compare favorably with glucose.

CONCLUSIONS

The determination of the exact or total amounts of carbon

dioxide produced by yeast is beyond the scope of this article, as

are also such problems as those concerning the ease of hydrolysis

of the various disaccharides by the yeast enzymes. However, from

the simple experiments cited above, several concluding statements

might be made:

1. That glucose and levulose cause yeast to grow much more

rapidly than any of the other common sugars.

2. That glucose, (and probably levulose) causes the most rapid

production of carbon dioxide.

3. That yeast grows better under aerobic conditions, but will

develop in the proper medium under at least limited anaerobic con-

ditions.

4, That in order to register gas in a gas tube, the gas must be

produced in sufficient amount to more than saturate the liquid, and at

a sufficient rate to overcome loss by diffusion through the open arm.

5. That a solid medium may materially alter the morphological

characters of the individual yeast cells by a tendency to localize the

food supply.

James Millikin University.

228 WILLIAM F. HENDERSON

EXPLANATION OF PLATES

Plate XXIII. Plate cultures onsugar agar. (1) Glucose; (2) Levulose; (3) Cane

sugar; (4) Maltose; (5) Lactose; (6) Agar without sugar.

Plate XXIV. Fig. 1, Margin of surface colony on sugar agar plate. Fig. 2, Edge

of deep agar colony showing filaments. Figs. 3,4, Elongated yeast cells, showing origin,

also method of branching. Fig. 5, Elongated cells, showing large vacuoles especially

in older cells.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

PLATE XXIII HENDERSON

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XXXVIII

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SECONDARY PROTHALLIA OF NEPHRODIUM

HIRTIPES HK

By W. N. STEIL

Although the prothallia of a large number of species of ferns were

grown under different cultural conditions to determine, so far as

possible, what factors are concerned in the formation of secondary

prothallia, the results herein described are based chiefly on experi-

ments with the prothallia of Nephrodium hirtipes for a description

of which the reader is referred to an earlier paper (Steil, 1919).

In the first culture of Nephrodium hirtipes, made December 14,

1913, most of the prothallia were destroyed by a parasitic fungus.

The healthy prothallia were carefully transferred to cultures made

by placing sphagnum into small Stender dishes. The sphagnum was

saturated with Knop’s solution, and the medium was then thoroughly

sterilized before the prothallia were transplanted. The cultures were

then placed in subdued light for a period of two weeks. In conse-

quence of the different light conditions, a large number of short

filaments, each consisting of a single row of cells, were produced from

the margins and occasionally from both surfaces of the prothallia.

The cultures were then placed for a like period of time under favorable

conditions of illumination in a Wardian case. It was now observed

that the filamentous prothallia broadened out and became heart-

shaped. The experiment was repeated several times with the same

culture and as a result of the changes in illumination numerous

secondary prothallia were obtained which upon separation from one

another became independent prothallia (Fig. 5, Plate XX VI). Fig.

1, Plate XXV represents a large secondary prothallium obtained

from one of the cultures. From a margin of the prothallium a lobe

(a) has been produced. A smaller heart-shaped prothallium (c) has

been formed as an outgrowth of the lobe. The posterior portion of the

large prothallium consists almost wholly of dead cells. The prothal-

lium bears an apogamously produced embryo (e) of considerable

size. An embryo of like origin had just begun its development on the

229

230 W. N.-STEIL

smaller prothallium. The secondary prothallia which were produced

after the primary prothallia were transferred from subdued light

to favorable illumination resembled those represented in Fig. 6,

Plate XXVI. These, however, as will be described later, were pro-

duced under different cultural conditions.

A culture of Polypodium crassifolium L. was placed under the

same conditions of illumination as those under which the culture of

Nephrodium hirtipes produced numerous secondary prothallia and

it was found that the former species exhibited a similar tendency to

form such prothallia. It thus appears that, although the prothallia

of Nephrodium hirtipes produce embryos apogamously, they possess

no greater tendency to vegetative growth than do those of Polypodium

crassifolium which produce embryos only as a result of fertilization.

In many cultures of Nephrodium hirtipes and several other species

of ferns, the method just described for producing secondary prothallia

was invariably successful.

Large portions of prothallia were removed from cultures in the

Wardian case and were placed on media like that of the cultures just

described. Some pieces were also floated on the surface of sterilized

tap water, and sterilized nutrient solutions. Even when the illumina-

tion was favorable for the formation of heart-shaped prothallia in

cultures made by sowing the spores, numerous secondary prothallia

were produced from the margins and surfaces of the larger pieces

(Fig. 2, Plate XXV).

When prothallia, growing under favorable light conditions, were

cut off near the substratum with a sharp razor, the remaining portions

of the prothallia likewise produced many secondary prothallia

(Steil, 1918).

In some of the cultures the prothallia were attacked by parasitic

fungi to such an extent that only small portions of the older prothallia

remained. From the apparently normal cells of such prothallia,

filaments were produced which developed into heart-shaped prothallia

when the cultural conditions became more favorable.

Occasionally the prothallia of Nephrodium hirtipes, especially

in the older cultures, became discolored or brownish, perhaps on

account of certain “physiological” conditions. The large majority

of the cells in such cases died. From the living cells secondary pro-

thallia were usually formed when more nutrient solution was supplied

PROTHALLIA OF NEPHRODIUM HIRTIPES HK 231

to the culture. The writer has observed in the vicinity of Madison

similar instances of regeneration of the prothallia of Onoclea sensibilis

L. which had lived over winter. In some cases only small portions

of the original prothallia had survived the winter conditions. From

these portions secondary prothallia were observed to form in pro-

fusion.

When the illumination was somewhat subdued, but not sufficiently

to produce only filamentous prothallia, one or more lobes of the

primary prothallium formed secondary prothallia (Fig. 3, Plate

XXV, and Fig. 6, Plate XXVI).

Prothallia of Nephrodium hirtipes on which apogamous embryos

had begun their development were placed under conditions of weak

illumination and these also formed secondary prothallia (Fig. 2

Plate XXV). The two regions, a and b, shown in the photograph, are

composed of cells containing few chloroplasts. Embryos of apoga-

mous origin have already begun their development in the paler

regions.

Under certain conditions of light to be described at a later time,

many branched cells were produced (Fig.7, Plate XXIV). When the

cultures were placed in the Wardian case, the branched cells formed

prothallia precisely like those originating from the germination of a

spore (Fig.8, Plate XXIV). Branched cells have been described by

Atkinson (1894), Miss Black (1915) and Miss Wuist (1916). Atkin-

son (1894) reported the formation of prothallia from branched cells

of Adiantum cuneatum.

In one of the cultures of Nephrodium hirtipes, a peculiar second-

ary prothallium was observed (Fig. 4, Plate XXV). The “light”

region present in the portion just back of the apical notch indicates

that an embryo of apogamous origin was about to make its appear-

ance. A number of clearly defined regions are shown at a, Fig. 4.

At bisa larger and more distinct area. All of those at a in a few days

fromed small prothallia. The prothallium was composed of only a

single layer of cells in thickness where the peculiar regions were

present. The writer is unable to give a satisfactory explanation

the prothallium described above.

Secondary prothallia were readily induced by any of the methods

which have been described. In every respect, such prothallia

232 W. N. STEIL

resembled apparently the primary ones, producing also embryos of

apogamous origin.

The formation of secondary prothallia from primary prothallia

have been described by a large number of investigators including,

Wiegand (1849), Hofmeister (1851), Kny (1870), Goebel (1877),

de Bary (1878), Bauke (1878), Beck (1880), Dodel-Port (1880),

Campbell (1892), Heim (1896), Britton and Taylor (1902), Lager-

berg (1906), Woronin (1908), Pace (1913), Heilbron (1910), Fischer

(1911), Schlumberger (1911), Wuist (1913), Nagai (1914), Pickett

(1914), Black (1914), Wuist (1916).

Deparimeni of Botany.

University of Wisconsin.

BIBLIOGRAPHY

ATKINSON, G. F.

1894. The Study of the Biology of Ferns by the Colloidin Method.

Bary, A. DE

1878. Ueber Apogame Farne und die Erscheinung der Apogamie in Allgemeinen.

Bot. Zeit. 36: 449-464, 465-480, 481-487. Pl. 14.

BaukKgE, H.

1878. Zur Kentniss der Sexuellen Generation bei den Gattungen Platycerium,

Lygodium, und Gymnogramme. Bot. Zeit. 36: 753-759, 769-780.

BEcx, G.

1878. Entwickelungsgeschichte des Prothalliums von Scolopendrium vulgare

Sym. Bot. Zeit. 36: 780. (Abstract)

Brack, C. A.

1915. Branched Cells of the Prothallium of Onoclea sensibilis L. Bull. Torr.

Bot. Club, 41: 617-620. Pls. 22, 23.

Britton, E. C. and Taytor, A.

1902. The Life History of Vittaria lineata. Mem. Torr. Club. 8: 185-211.

Pls. 23-31.

CAMPBELL, DouGHLAS HouTon.

1892. On the Prothallium and Embryo of Osmunda claytoniana L and O.

cinnamonea L. Ann. Bot. 6:49-95. Pls. 3-6.

DopEt—Porrt, A.

1880. Das amphibische verhalten der Prothallien von Polypodiaceen. Bot.

Zeit. 38: 525. (Review)

FIscHER, H.

1911. Wasserkulturen von Farnprothallien mit Bermerkungen ueber die Bedin-

gungen der Sporenkeimung. Beih. zum Bot. Centralbl. 27: 54-59.

GOEBEL, K.

1877. Entwickelungeschichte Farnprothallien mit Bemerkungen ueber die

PROTHALLIA OF NEPHRODIUM HIRTIPES HK 233

Bedingungen der Sporen keimung. Bot. Ziet. 35: 671-674, 681-

694, 697-711. Pl. 12.

HEILBEON, A.

1910. Apogamie, Bastardierung und Erblichkeitsverhiltnisse bei einigen Farnen.

Flora 101: 1-42, f. 1-43.

Hens, Carr.

1896. Untersuchungen ueber Farn-prothallien. Flora 82: 329-73.

HOFMEISTER, W.

1851. Vergleichende Untersuchungen der Keimung, Entfaltung, und Frucht-

bildung héherer Kryptogamen und der Samanbildung der Coniferen.

Leipsic.

Kwny, L.

1870. Ueber den Bau und die Entwickelung des Farn-antheridiums. Monatsher.

K. Preuss. Akad. Wiss. Berlin. 416-431. f. 1-19.

LAGERBURG, T.

1906. Zur Entwickelungsgeschichte des Pteridium aquilinium (L) Kuhn. Arkiv.

Bot. 65: 1-28. Pls. 1-5.

Nacat, [susuro.

1914. Physiologische Untersuchungen ueber Farn-prothallien. Flora 106: 281-

230.

Pace, Lora.

1913. Some Peculiar Fern Prothallia. Bot. Gaz. 59: 49-58, f. 1-11.

Pickett, F. L.

1914. The Development of the Prothallium of Camptosorus rhizophyllus. Bot.

Gaz. 57: 228-238, pl. 12, 13, f. 1-41.

SCHLUMBERGER, O.

1911. Familien-merkmale der Cyatheaceen und Polypodiaceen und die Bezie-

hungen der Gattung Woodsia und verwandter Arten zu beiden Familien.

Flora 102: 383-414, f. 1-15.

STEIL, W. N.

1918. Studies of Some New Cases of Apogamy in Ferns. Bull. Torr. Bot. Club,

45: 93-108. Pl. 4, 5.

1919. A Study of Apogamy in Nephrodium hirtipes. Hk. Ann. Bot. 33 109-132.

Pls. 5-7.

Wiecanp, A.

1849. Zur Entwickelungsgeschichte der Farnkrauter. Bot. Zeit. 7:17-26,

33-40, 49-54, 73-80, 89, 97, 105-116. PI. 1.

WoronIN, HELENE.

1908. Apogamie und Aposporie bei einigen Farnen. Flora 98: 101-62.

Wurst, E. D.

1913. Sex and Development of the Gametophyte of Onoclea struthiopteris.

Physiol. Researches, 1: 93-132. f. 1-15.

1916. Branched Prothallia in the Polypodiaceae. Bull. Torr. Bot. Club, 43:

365-383, f. 1-15.

234

W. N. STEIL

DESCRIPTION OF PLATES

PLATE XXV

The prothallia from which the photo-micrographs 1, 2, and 3 were made, were

magnified about 25 times. Photomicrograph 4 represents a magnification of about 30

times.

Fig.

1. A prothallium of Nephrodium hirtipes. A large lobe, a, has been produced

from the prothallium. From the lobe a smaller heart-shaped prothallium, c, has

been formed. Apogamous embryo, e.

2. Aprothallium of Nephrodium hirtipes from which many secondary prothallia

have been formed. Regions in which apogamous embryos are beginning their

development, @ and db.

3. Aprothallium of Pteris cretica albo-lineata from one lobe of which regeneration

has taken place. An embryo of apogamous origin has also begun its development

at a.

4. Apeculiar secondary prothallium of Nephrodium hirtipes. Distinct prothallial

regions at a and b.

PLATE XXVI

5. A culture of Nephrodium hirtipes containing numerous secondary prothallia.

X1\%

6. Prothallia of Nephrodium hirtipes from the lobes of which secondary prothallia

have been produced. X 2)4.

7. Branched cells of Nephrodium hirtipes. X About 42.

8. A young prothallium of Nephrodium hirtipes produced from a branched cell.

X 42.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL ie

SOCIETY, VOL. XXXVITI

PLATE XXV STEIL

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL

SOCIETY, VOL. XX XVIII

Fig. 7 Fig. §

PLATE XXVI STEIL

DEPARTMENT OF NOTES AND REVIEWS

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 mem-

bers are invited to submit such items. In addition to 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.]

RECENT CHANGES IN ILLINOIS RIVER BIOLOGY

Forbes and Richardson (Bull. Ill. Nat. Hist. Survey, XIII; 6,

April 1919) present an abstract of changes in the biology of the

Illinois River in the last twenty years. The chief causes of change

are: The increase in the volume of the water due to the opening of the

Chicago drainage canal in January, 1900; the great increase in the

sewage content of the water due to the same cause; and reclamation

of the river bottoms for agricultural purposes.

To illustrate the first of these items it is stated that just one-half

the average flow at Peoria for 1913 was thus derived from Lake

Michigan. This tends to give constancy to the height of the river,

but increases the overflow in high times and extends the period.

Depth of river and rate of flow are both increased. The bottom-land

lakes which stand at approximately the river level are also corres-

pondingly heightened. Numerous summer shallow-water weedy

belts are eliminated. The increased rate of flow insures that the

decomposition and assimilation processes formerly occurring in a

given length of stream take place further down stream. The results

are as tho the stream had been shortened. Carried organisms have

less time to multiply and less chance of being devoured in given length

of river. The point where the decomposing sewage becomes available

for green plants and other plankton is further down stream than

before. All the dependent vital phenomena take place further

down the river. In spite of the increase of sewage in the river, the

rate of flow and volume of water make it true that the river water

contains a smaller percentage of sewage in 1914 than before 1900.

_. The total result of this is that optimum conditions for green

plankton which apparently occured at or above La Salle before 1900

now occur not much above Peoria. From this point to the mouth of

235

236 NOTES AND REVIEWS

the river the food supply in smaller and larger plankton organisms is

greatly increased.

The results of levees preventing overflow of the bottoms, together

with the draining of the tributary lakes operate in the opposite

direction. These stagnant and semi-stagnant waters are perpetually

productive of plankton and feed the river with it. With the progres-

sive elimination of the sources a further reduction in the river plankton

may be expected.

The total effects of the changing conditions, expressed in terms

of the fisheries, are interesting. The increase of yield of fish for the

five years preceding the opening of the drainage canal was about 9

per cent per annum; that for the eight years following averaged an

annual increase of about 3.5 per cent; while for the next four years

there was an average decrease of 15 per cent per annum, based on

statistics from Havana.

Three factors during this time tended to increase the yield; the

introduction of the sewage with its increase of organisms; the rapid

increase of European carp which in 1908 furnished 64 per cent of the

total product; and increased interest in fishing due to this increase.

The rapid progress of reclamation would operate to diminish the

yield. The factor of increased fishing doubtless operated in the same

way for the later years. The catch was greater than the increase.

It is the purpose of the Survey to find by investigation the treat-

ment, both of the river itself and its adjacent and tributary regions,

which may so far as possible allow the maintenance of the fishery

properties of the state.

FROGS AND TOADS IN BERMUDA

Pope (Bul. Mus. Comp. Zool. Harvard Coll. May 1917) presents

a brief account of the three species of Anura found in the Bermudas.

These are Bufo agua, the Great Surinam Toad; Eleutherodactylus

johnstonei, the ‘‘whistling” tree frog; and E. luteolus. No amphibian

is native to Bermuda. The Bufo was imported from British Guiana

to capture garden insects, about 1885. The “whistling frog’’ is

thought to have been brought from the Barbadoes, and is known to

the Islands as far back as 1880. The E. luteolus was discovered in

1916, and nothing is known as to its origin.

There are two points of unusual interest in connection with the

situation. The first is that Bufo agua is the largest of living toads.

AMERICAN MICROSCOPICAL SOCIETY Sf

The second is the extremely unfavorable conditions in the Bermudas

for amphibians. The limestone of the Islands is so porous that the

rain water which falls on the land quickly seeps back to the sea.

There are no streams and no permanent pools. The tadpoles of the

Great toad have become able to develop in brackish water. In

E. johnstonei the entire larval development takes place in the egg,

and the frog hatches out in the adult form. All that is necessary

therefore is that the eggs be laid in moist places—as under leaves:

and stones.

The first two species grew in numbers rapidly within a few years

after introduction, but later gradually established a balance at some-

what lower numbers.

GONADS AS CONTROLLERS OF SOMATIC AND PSYCHICAL QUALITIES

Moore (J. Exp. Zool., May 1919) reports experiments on rats

confirming in part Steinach’s conclusions respecting the effect of

grafting ovarian tissues in completely castrated males. Steinach

found that such “feminized males’’ behaved more like females than

males both physiologically and psychically. Growth of mammary

glands and the secretion of milk were noted in such males. Similarly

females in which testicular tissue was substituted for the ovaries

resembled males both in body and temperament.

In these grafting experiments two distinct changes are wrought :—

the native sex bodies are removed, and bodies of the opposite sex

are inserted. It is necessary therefore, to observe as controls both

uncastrated animals, and castrated ones into which no exogenous

elements have been introduced.

The distinguishing characteristics of the sexes in the white rats

are not sharply marked in features other than the sexual organs

themselves. The growth curves of weight and body length differ

somewhat in males and females, the male being somewhat higher.

Castration of male rats seems not to modify the growth curve,

while spaving the female increases the curve over that of the normal]

female. Hair, mammary glands, changes in skeleton, and fat deposit

have all been suggested as presenting differences. The author,

however, feels that there is too much variation in all these things

for them to have any exact value as criteria. He holds that the

characteristic behavior of the sexes gives much better means of

238 NOTES AND REVIEWS

measurement than the features mentioned. This would include mat-

ing reactions, rivalry and fighting, parental behavior toward young,

and the like.

Moore finds definite evidence that masculinized females show

exact male copulatory sex reactions and that feminized males

show a tendency toward maternal behavior with the young. The

interchanged sex hormones appear therefore to modify the psychic

nature of one sex in the direction of the other.

CONTINUOUS VARIATION, AND ITS INHERITANCE IN PEROMYSCUS

Sumner (Amer. Nat. 1918, p. 177; 290; 439) finds evidence of

continuous variation, subject to selection and to blending in inheri-

tance, as well as evidence of other variations which are discontinuous

and behave in breeding in accordance with Mendelian expectations

in four local races of the wild deer-mouse Peromyscus maniculats.

These continuous variations relate both to pigment and to measur-

able structural features. These observations furnish cogent materials

for further denial of the all-sufficiency of the extreme “‘Mendelian-

mutation-pure-line”’ interpretation of evolution.

MOULT AND REGENERATION OF PELAGE IN DEER-MICE

Collins (Jour. Exp. Zool., Oct 1918) records observations on the

normal moult of several varieties of deer-mice and on regeneration of

the pelage after artificial removal.

The general body is destitute of hair and pigment at birth. The

upper parts of the body begin, on the second day, to assume a bluish-

black tinge and the hair begins to come thru the skin. The ventral

white hair begins to show a day or two later. The characteristic

juvenal pelage is attained in four or five weeks. This is made up of

a thin coat of long and coarse overhair, filled between with a fine soft

underfur. The hairs of the underfur are agouti,- slate colored at

base, a narrow intermediate band of pale mouse gray near the tip,

anda blacktip. The overhairs lack the intermediate band,- not being

agouti. The ventral surface is similar except that the tips of the

hairs are white. The line between the deep gray of the back and

the white of the belly is very sharp.

The transition to the post juvenal pelage begins at age of six

weeks and requires about eight weeks for completion. It begins to

appear at the throat and proceeds dorsally and anteriorly, then

AMERICAN MICROSCOPICAL SOCIETY 239

posteriorly by a quite definite route and rate of extension The ven-

tral moult is completed before the dorsal. This pelage is somewhat

longer and coarser, with a distinct color effect dorsally varying from

umber to sepia, and due to increased yellow pigment in the inter-

mediate band of the hair.

The young mice were etherized and the hair plucked out over cer-

tain areas, without injuring the skin. Where the juvenal hair was

removed it was replaced directly by the post-juvenal. The artificial

removal of hair modified the normal sequence of appearance of post-

juvenal pelage over the body quite definitely. Usually this modifica-

tion was confined to the regions actually depilated; but not always.

It sometimes influenced the succession at a little distance.

A precocious appearance of the post-juvenal pelage may be

induced by removing the juvenile hair.

Restoration takes place in removed adult pelage, and occurs

irrespective of seasons. It is restored somewhat more rapidly when

hair is plucked out than when it is merely cut. Light appears to have

no influence in developing the differences of color in dorsal and ventral

surfaces.

EXPERIMENTS ON PROTECTIVE COLORATION

Young (Jour. Exp. Zool. May 1916) reports experiments in which

crows, hawks, owls, chickens, prairie chickens, grackles, kingbirds

and martins are used as preyers, and amphibians, small mammals

and insects as prey. The work was done in cages, and varying back-

grounds, which contrasted with and concealed the prey were used.

He concludes; (1) that protective resemblance is effective in protect-

ing motionless animals from attacks by caged birds; and (2) stillness

is probably a more important factor than color in protecting animals

from their foes.

COLOR DISCRIMINATION AND ASSOCIATION IN FISHES

White (Jour. Exp. Zool., Feb. 20, 1919) concludes from experi-

ments on mudminnows and stickebacks that they were able to

discriminate, in differing degrees, such colors as red and green, and

that the discrimination is based on wave length and not upon inten-

sity. Their power of discrimination is less than that of man.

Effective associations between certain colors and behavior were

shown by their learning to leap out of the water for food announced

by various colors. In a similar way associated actions were shown

240 NOTES AND REVIEWS

for movement of objects in the water, for movements of the operator,

for jarring the vessel in which they were. There was no evidence of

ability to discriminate patterns, altho they discriminated the shape

of objects, such as a dobson-larva.

Their behavior is stereotyped. The associations are few and

simple—such as relate directly to their life struggle. They were

able to learn nothing as complex as passing thru a definite opening

to secure food. The associations are fairly permanent, lasting as

long as 42 days. They are more difficult to modify than to establish

at the outset.

AGE AND FERTILITY IN FOWLS

Pearl (Proc. Nat. Acad. Sci., 1917, 3, p. 354) compares the cycle

of progress in the fertility of mammals and poultry. In mammals

fertility seems to begin below the maximum, increase, and then

decline until sterility is reached. In fowls the maximum seems to

occur at the first breeding season—when the combined age of the

parents at mating is only two years. There is a strong drop from this

to the point where the sum of the ages is three years. From three to

four there is little change. In passing from this period to a combined

parental age of five years there is another large drop.

The same author (Genetics, 1917, 2, p. 417) formulates a fertility

index which represents a practical measure of the reproductive value of

mated pairs of domestic fowls. This is that percentage of the maxi-

mum total number of chicks physiologically possible, which any

given mating shows. It includes the total number of chicks produced

which are capable of living three weeks after hatching. In the rapid

decline in fertility expressed above, the rate of decline is more rapid

in the male than in the female.

SEX RATIO IN CHICKENS

Pearl (Science 1917, 46, 220) states that the normal per cent of

cockerels is 48.57. It seems that this ratio is correlated with the

laying ability of the hens. In hens which have been bred and selecte

to a high egg productivity, a still larger proportion of pullets is pro-

duced.

NEW PROCESS OF KEEPING FISH BY BRINE FREEZING

Gardiner and Nuttall (Proc. Cambr. Phil. Soc. 1918; 19:185) give

an account of a brine freezing process at high temperature which pro-

AMERICAN MICROSCOPICAL SOCIETY 241

duces no breaking down of muscle, nor loss of aroma or flavor. The

brine is of 18% salt. A temperature of 5 °-20°F. willserve to freeze

a large fish in three hours; a herring in twenty minutes. The better

preservative results are due to the fact that in ordinary freezing large

ice crystals are formed in and among the muscle fibres. This breaks

up the texture of the flesh. In the brine freezing the tissues are

unchanged because only small crystals are produced.

FOOD OF YOUNG FISHES

Lebour (Jour. Marine Biol. Assoc. 1918, p. 433) states that some

very young fish eat diatoms and other single celled organisms before

they begin to eat animal food in the plankton. By a study of some

fifty species she concludes, however, that all except a few vegetarian

fishes, depend upon the small animals of the plankton rather than

upon the algae. These food animals are Cladocera, Copepods,

cirriped larve, and eggs. These crustacea feed freely on the micro-

scopic plants.

STIMULI AND REACTIONS OF SAND CRAB

Mead (Univ. Cal. Zool. Publ. 1917, 16) reports experimenial

studies upon the sand crab so abundant on the tidal beaches of

California. He found that the range of stimuli to which they are

adapted is quite limited. Their eyes are effective, and guide them to

their feeding beds and in the avoidance of enemies. Their feathery

antennae aid them in capturing small organisms for food.

Their most striking reactions are in burrowing when uncovered,

and in making their way back to the water when out ofit. Two tend-

encies aid in the latter reaction; (1) they tend to run down slopes;

(2) when not further than 200 feet from the ocean they tend to go

toward it, even when they cannot see it. Even tho near the ocean

they will, however, follow a 7 per cent slope away from it.

REACTIONS UNDERLYING THE DIURNAL MIGRATIONS OF

VARIOUS PLANKTON ANIMALS

Esterly (Univ. Cal. Zool. Pub., April 4, 1919) reports experimental

studies of the behavior of various plankton animals in the laboratory,

conducted with the purpose of determining the factors that account

for their diurnal migrational habits in nature. The author calls

242 NOTES AND REVIEWS

attention to several definite reversals of response in laboratory con-

ditions as compared with what is shown immediately after being

taken from the sea. This greatly complicates the practical problems.

In general the plankton animals of a given species are more

numerous at higher levels and less abundant at lower. One form may

range from the surface to 100 fathoms, and another from 100 to 200

fathoms. What are the factors which operate to produce this result?

The rhythmic quality suggests that the action of light in day

and night is responsible. Clearly, also gravity, increase of pressure,

salinity, temperature, and the like enter along with light into the

problem. Equally also there may be internal or physiological rhythm

apart from anything external.

The following general conclusions are suggested:

much as there are quick specific reversals in behavior under

stimulus.

(2) While there are some experimental reversals of geotropism,

change in geotropism because of change in light intensity cannot

account wholly for vertical migration as a general phenomenon.

Geotropism is, however, usually positive when the light is

vertically above the water.

(3) The same limitations must be made with respect to changes

in temperature as explanatory of general migrations.

(4) Physiological rhythm is shown in some species, under certain

conditions, and may enter into the explanation of diurnal

migrations. |

ARCELLA EXCAVATA NOV. SP.

Habitat: Found in small swamp along with other varieties near

Durham, N.C. First noted occurrence Dec. 9, 1918.

Shape: Somewhat like a quarter-section of cantaloup, the mouth

being situated in the cup.

Size: Length 55y, width 50y, total depth 45u, depth of depression

25u, mouth 15x20p.

Color: Brown to almost black.

AMERICAN MICROSCOPICAL SOCIETY 243

Differs from A. discoides Leidy! in contour. Other difference can

not be determined since Leidy does not describe the indidivuals. It

differs from A. curvata of Wailes? in size and contour. A. curvata

is about three times as large, and has a thickness about )4 its diame-

ter while A. excavata has a thickness nearly equal to its diameter. A.

curvata is rather saucer shaped while A. excavata is U-shaped.

Fig. 1. Side View. Fig. 2. Oral View.

The author wishes to acknowledge the assistance rendered by

Dr. C. H. Edmondson, who agrees with the author that this is a

probable new species and has suggested the name given.

1 Fresh Water Rhizopods of North America. Joseph Leidy. U. S. Geological

Survey of the Terr. 1879.

2 Fresh Water Rhizopods from N. and S. America. Wailes. Journal. Linn. Soc.

Zoology 32:203.

BERT CUNNINGHAM.

Trinity College,

Durham, N.C.

CARPENTER ANT DESTROYING SOUND WOOD

Graham (Report State Ent. Minn., 17, 1918) refutes the standard

statement that the carpenter ant, Camponotus pennsylvanicus Degeer

works merely in decaying wood, but does not attack sound material.

The author finds the ants attacking the solid heart wood of living

cedar trees in Minnesota.

It seems true that they always attack a tree by way of some wound

or decayed spot. In as much as few trees of pole size are without

some such diseased areas, much of the cedar harbors colonies. After

a colony is established in a tree the ants work upward from the rotten

244 NOTES AND REVIEWS

area into the sound heart wood, excavating it with longitudinal

galleries until only a thin shell of sound wood is left. From the main

body of occupied nest they cut lateral openings to the outside, called

‘“windows” by the woodsmen. The topmost window marks approxi-

mately the upper limit of damage. The writer makes practical

suggestions leading to the conservation of the wood in cutting the

poles with respect to this condition and at the same time sufficiently

to protect the buyers.

DROSOPHILA IN BOTTLED CERTIFIED MILK

Riley (Report State Entomol. Minn. 17, 1918) reports frequent

occurrence of the puparium of a species of Drosophila on the inside

of bottles of certified milk. The occurrence of these objects has been

recognized by many of the distributing companies, whose employees

referred to them as “‘hay-seeds.”” It was concluded that the eggs are

laid in unwashed bottles to which the flies are attracted by the

souring milk. The larvae are so nearly transparent as to escape

notice, and adhere so tightly that they are not removed by washing.

They are of course killed and rendered innocuous by the cleansing

treatment in any properly managed dairy, where the bottles are

treated by a hot, almost boiling, caustic solution. The inability of

the author to rear any flies is reasonable evidence of the soundness

of this conclusion. Such episodes certainly make apparent the

necessity of enforcement of regulation for cleansing of milk bottles,

as soon as emptied, by consumers.

TROPHYLLAXES: A NUTRITIVE EXCHANGE AMONG ANTS

Wheeler (Proc. Amer. Phil. Soc. 1918, p. 293) in a most suggestive

paper offers a suggestion as to one of the possible elements underlying

the social life of ants. In certain Ponerine ants the workers turn

the larvae on their backs while they are being fed. Fragments of

insects are placed on the concave ventral surface. This stimulates

the larvae to secrete and discharge a fluid, comprizing blood serum,

other nutrient matters and a proteolytic enzyme. The secretion may

exude thru the pores of the skin or from special glands. There may

be special tubercles or other outgrowths. These materials are licked

off by the nurses. This exchange of foods between larvae and workers

AMERICAN MICROSCOPICAL SOCIETY 245

suggests the relationship known to exist between some species of

ants and plant lice. Such a symbiotic relation might well modify

community life.

NUTRITION OF INSECTS IN RELATION TO MICROORGANISMS

Many insects live on plant food which is rich in carbohydrates but

relatively low in protein. Because of the one fact insects may show

great activity while, owing to the lack of protein, their growth may be

both limited and slow. Some forms have a long life cycle altho

ingesting great quantities of the substratum. This argues low meta-

bolic rate in spite of large ingestion. On the other hand, many

insects using fermenting vegetable matter with very low protein

content have a very short and rapid growth period. This suggests

an unapparent protein constituent. Baumberger (Jour. Exp. Zool.,

April, 1919) reports a study designed to discover the source of the

protein supply of such insects. Drosophila in fermenting fruit,

sarcophagous flies, coprophagous flies, fungus gnats, and other

insects were used. The experiments on the Drosophila were especially

thoro. By crucial experiments the author shows that the insect,

while able to live on sterilized fruit alone, only has its normal rapid

growth rate when this fruit diet is accompanied by microérganisms,

particularly yeast. The yeast is a more adequate food than the

fruit because of its higher protein content. Similarly the other

insects, mites, and the like studied were shown to ieed on microérgan-

isms, thus generally supplementing their diet by the power of the

fungi to extract, absorb, and synthesize the many non-protein

compounds.

The author gives grounds for believing that this dependence of

insects upon fungi is wide-spread. This is another measure of the

great adaptability of insects in respect to available foods. Three

modes of availing themselves of these high-class fungous foods are

mentioned: (1) Ingestion of the microdrganisms with the substra-

tum, as in larvae of Drosophila, Musca, etc.; (2) Feeding directly on

the microdrganisms, as mites, crickets, many adult Diptera; (3) Pre-

paration of an organic medium for the growth of microérganisms, as

leaf-cutting ants, termites. Attention is called to the fact that

animals other than insects go to the same source for food—as Pro-

tozoa, probably nematodes, and possibly earth worms.

246 NOTES AND REVIEWS

In addition microérganisms are internal symbiants in insects and

other animals. In the intestine of higher animals, these may elabor-

ate protein from non-proteins, or serve other ends, as preserving a

constant digestive flora. In still other locations, as fat bodies, coeca

and the like, they may destroy waste products of metabolism, produce

digestive enzymes, etc. The exact value of these internal relations,

however, is by no means securely established.

PROBLEMS OF FERTILIZATION

In a book with this title, Lillie has placed in brief and semi-popular

form a discussion of the problems of fertilization to which he himself

has made notable contributions. Fertilization has long been recog-

nized as a critical and decisive process in all plants and animals in

which sex appears, and has appealed keenly to human interest from

the earliest times. Every modern step in the study of genetics,

variation, inheritance, and breeding from any angle whatsoever has

paid tribute to and received support from investigations in the

chemical and architectural composition and the behaviour of the egg

and sperm as these cells unite in fertilization.

In the first chapter the author traces the history of human specu-

lation and discovery in respect to eggs and sperm and the manner

and meaning of their coming together. Few items of biological pro-

gress illustrate better the gradual passage from the metaphysical

philosophical subtleties of a@ priori reasoning than this field shows.

The discovery of the living sperm, by Leeuwenhoek and others, soon

after the invention of the microscope, at first only gave a more riot-

ous zest to these speculations. But gradually increased knowledge of

the facts, coupled with definite limiting experiments, chastened these

theories and led to the recognition of the coérdinate value and func-

tion of the male and female elements.

The intimate cytological investigations of the last quarter of the

nineteenth century finally brought into clear view the full significance

of the cell—and nuclear—theory and made possible its final applica-

tion to fertilization. There has been no more brilliant biological work

in any field than that which relates to the behavior of the nuclear

elements in maturation and fertilization.

There are two sets of problems at this point “where all the strands

of the webs of two lives are gathered in one knot, from which they

AMERICAN MICROSCOPICAL SOCIETY 247

diverge again and are re-woven in a new individual life history.’

One group relates to the specific morphological and physiological

problems of fertilization. The other includes questions of inheritance.

It is to the first of these that the book is directed. Progress in recent

years has been in perfecting our knowledge of the actual structures

and processes involved in the bringing of these two nuclei together

in one cytoplasmic mass; and in the much more difficult and less

known realm of the physiology of fertilization, including as it does all

the actions and reactions of the external and internal elements of

these cells as they unite, as well as the factors external and internal

that inhibit or limit these reactions.

Chapter II gives striking expression to the place of fertilization

in the life history of organisms. While recognizing the generally

accepted view that mature egg and sperm cells are senile cells in the

sense of possessing such differentiation that neither alone, under

ordinary circumstances, can go on with development, the author feels

that the inner meaning of sex and fertilization is not fully expressed

by the rejuvenescence and de-differentiation that accompanies

union. He recognizes an underlying and “‘invevitable dimorphism of

living matter’’ which sets them apart from all other specialized and

senescent cells. Furthermore fertilization is the vehicle for inheri-

tance both in preserving old qualities and in introducing variations.

Thus fertilization furnishes material for natural selection to work on.

There is evidence also that the result of the union of contrasting

germplasms gives greater vigor in offspring—a further accent upon

this underlying dimorphism.

Chapter III deals with the morphology of fertilization. In this

chapter the author restates the outstanding steps in maturation, the

structure of the elements, the method of bringing the cells into

mutual influence, the mechanics of the entrance of the sperm into the

egg and the resulting changes in the surface apparatus of the egg

itself, the fate of the parts of the spermatozoon and their relation to

the ovarian structures.

The author summarizes interestinly the relation of the maturing

of the germ cells to the act of fertilization. In the case of the sperm

cells the maturation divisions always precede the special differentia-

tion of the locomotor elements. In the case of the ovum, however,

248 NOTES AND REVIEWS

there is a great variety in the relation of maturation and fertilization.

In echinoderms and some other animals the maturation divisions of

the ovum are completed before fertilization. This is the typical

condition—of our text books. In many animals, on the contrary,

the ovum is unable to complete or sometimes even to begin the divi-

sions leading to maturation until stimulated by the entrance of the

spermatozoon. For example, in many vertebrates the first polar

body is formed and the nucleus enters upon the prophase of the

second but is unable to complete the process without fertilization.

In other instances the ovum is able to effect the prophases of the

first division, but is checked permanently in the metaphase unless

the egg is fertilized. In Nereis and some other Annelids the egg will

pass thru none of the maturation steps without precedent fertiliza-

tion.

These variations impress most strongly the loss of power, almost

degenerative in character, seen in the maturation of the germ cells,

in contrast with the stimulating character of their union. In these

cases where entrance of the sperm is necessary to insure complete

maturation, the sperm elements rest quietly in the egg until the

maturation steps are finished. The preliminary or external phase of

fertilization includes such events as the approach and attack of the

sperm cell, penetration of sperm, the response of the cortical egg

cytoplasm which aids the sperm nucleus in its progress, the special

development of the perivitelline structure, which probably tends to

prevent polyspermy and otherwise modifies permeability, respiration,

and other metabolic and developmental processes.

The actual or internal fertilization involves the study of the

fate of the portions of the sperm cell which enter the egg cytoplasm.

These consist universally of sperm nucleus which represents the

nuclear chromatin in its most concentrated form; and certain small

sperm cytoplasmic elements which differ greatly in different groups

of animals—from nothing to a very considerable portion. The author

conceives that the course of the male nucleus in the cytoplasm is due

neither to initial direction at penetration nor to attractions between

the nuclei; but rather that they move together because of independ-

ent movements forced upon them by the stresses of a common

cytoplasm, somewhat as two chips might come together in an eddy.

AMERICAN MICROSCOPICAL SOCIETY 249

A most profoundly important morphological problem is that of

the equivalent and representative character of the chromatin

(chromosomes) of the male and female nuclei. About this item has

arisen our most adequate interpretations of inheritance from the

embryological side.

The other constituents of the sperm to enter eggs are the beak

and tail of which there is no demonstrable history; the sperm centro-

some, and mitochondria. There is great variation in respect to sperm

centrosomes. The author believes that the sperm aster which arises

shortly after the sperm has penetrated the egg cannot be attributed

uniformly, if at all, to a sperm centrosome entering with the sperm.

The middle piece of the sperm does not enter at all in Nereis; and by

mechanical means he has been able to remove the middle piece from

sperm nuclei—which nevertheless formed the aster at the customary

place and in the usual way. Aster formation then he ascribes to the

influence of the sperm nucleus itself rather than to an inherited

centrosome.

While not denying that sperm mitochondria, which have been

traced for several cell generations in cleavage, may function in the

egg, the author holds that they show no evidence of being dimorphic

in composition or behavior when compared with those of the egg

itself.

One remaining substance, the egg cytoplasm is still to be men-

tioned. In quantity it is quite the most impressive material to be

considered. It must determine in high degree if not exclusively the

early embryonic steps. These processes and characters may fairly

be said, therefore, to be exclusively maternal in their origin. And

the cytoplasm, from the point of view of inheritance, might well be

the determiner and conserver of the basal racial trends. The maternal

cytoplasm would, however, be gradually used up—and all restoration

and increase would be the joint product of the cytoplasm and the

biparental nucleus. Thus we might expect the later stages of indivi-

dual development to be increasingly the product of this nucleus,

unless there may be some permanent elements in the cytoplasm

which grow and reproduce independently of the nucleus.

Under the caption ‘Physiology of the Spermatozoon,’’ Chapter

IV discusses such questions as these: What sensitiveness and modes of

behavior have spermatozoa? To what extent are their actions

250 NOTES AND REVIEWS

determined by the conditions of the media? What are the optimum

conditions for them? The principal facts about them may be sum-

marized as follows. Spermatozoa are shown to be exceedingly

sensitive to some external conditions. While usually without motion

in the testis and the ducts leading from it, they readily become mobile

under the operation of various natural and artificial media. They

are little influenced by light or gravity. They are sensitive to changes

in osmotic pressure, and more so to increase than to decrease of it.

Temperature affects the rate of their movement as measured by the

time required to aggregate.

The most important factors in determining the behavior of

spermatozoa are contacts and the chemical character of the medium.

The chief ways in which these factors operate are (a) by increase or

decrease of activity, (b) by producing aggregations of spermatozoa

thru chemotaxis; (c) by reversible agglutinations; and (d) by

thigmotactic adherance to surfaces of various kinds.

Various media, differing in different types of sperm, may activate

quiet sperm. In mammals the secretions of the prostate and other

glands normally activate sperm. In other instances sperm may be

made active by physiological salt solution, by sea water, with or

wihout an excess of OH ions. Im general the medium in which

insemination normally takes place will render them active. For the

most part they are extremely sensitive to changes in these media.

Addition of acids to sea water decreases activity and causes paralysis.

Saturation of sea water with COs completely paralyses. Alkalies in

general increase activity up to the lethal strength. Other things

being equal the degree of activity of spermatozoa is a function of the

H ion concentration of the medium.

Fresh active sperm in suspension in their inseminating medium

rapidly aggregate in masses. This action is due to rapid CO: pro-

duction by the moving spermatozoa themselves. They collect in any

region of increased CO: tension. This proceeds as tho the spermato-

zoa assume a positive orientation in a CO: gradient. The author

believes this is the actual explanation of the reaction.

Now it is known that the eggs of marine animals normally give off

into the sea-water, before fertilization, COz and other complex sub-

stances. These egg secretions have striking effects upon the sperm.

In some types of sperm these secretions make immobile sperm highly

AMERICAN MICROSCOPICAL SOCIETY Zak

motile. They also produce aggregation of the sperm, such as is

shown about CO:-producing centers; and, third, in some species

cause a coherence or sticking together of the heads of the spermatozoa,

—called ‘‘agglutination,”’ which is quite distinct from the chemotac-

tic aggregation. This agglutinating reaction is reversible; that is, the

masses may later break up without the sperm suffering any toxic or

other effect. The specific substance that causes agglutination is a

peculiar product of the egg. It is not contained in the blood or other

extracts of the female body. It is produced only by mature eggs, and

ceases when they are fertilized. Its production is coincident with the

period during which the egg may be fertilized.

The agglutinating substance is colorless; will not pass thru a

Burkefeld filter; will pass thru specially hardened filter paper; is

non-dialyzable; is only slowly destroyed at the boiling point; pre-

serves its power in sea-water for months, tho it does slowly disinte-

grate. Chemical and efficiency tests suggest that it has analogies to

the ferments.

The union of egg and sperm depend upon motion of sperm to the

egg, adhesion to it and penetration of it by the sperm. It is clear,

therefore, that the egg secretion by stimulating motion in the sperm,

by guiding its orientation, by developing an adhesive surface thru

the agglutinating substance—ail coupled with the well established

thigmotropic reaction of the sperm, furnishes a highly adjusted

situation leading toward this event.

In Chapter V the general relation of the physiological events

involved in fertilization is treated. There are certain essential tho

elementary features about the intimate process of fertilization which

the author does well to stress. For example, fertilization must not be

thought of as synonymous with the penetration of the egg by the

sperm. Fertilization is as a matter of fact a complex and progressive

reaction, of which penetration is an initial portion. It is a very defi-

nite series of events complete only when the inseminated egg is fully

capable of development and of transmitting the inherited character-

istics. Furthermore, fertilization is an “irreversible” reaction when

considered as a series. That is to say, after responding normally

in the cycle of reactions neither of these cells can go back to the

physiological state that existed before that response. Most cells,

after being stimulated and functioning, are able sooner or later to

252 NOTES AND REVIEWS

return to the beginning phase and repeat the cycle. The egg and

sperm are in a critical phase which prohibits reversibility.

Fertilization is possible only for a very limited and very definite

time in the life of the spermatozoon and egg. Unripe sperm will not

fertilize and unripe eggs cannot be fertilized. Both become aged and

cease to be functional. The time required for this differs. Ordinarily

it is very short, especially after sperm or eggs reach an external med-

ium; altho sperm may remain functional in the sperm ducts of the

male for weeks or months. Similarly, where internal insemination

occurs, sperm may remain potent for considerable periods; as in fowls,

for two or three weeks, or in bats for as much as six months.

The author adduces some most interesting experiments to show

the rate of decrease in fertilizing power in sperm, and that motility is

not the sole measure of fertilizing power. In respect to both sperm

and ova the writer believes that the power of fertilization depends

upon the presence of a specific substance produced by the cells. In

the case of the sperm he regards it as probable that this is identical

with the agglutinable substance of the spermatozoa. In the egg

the onset and waning of the capacity to be fertilized is due to the

formation and loss of a (hypothetical) substance which he calls

fertilizin. Fertilization itself, in all kinds of eggs, causes loss of

power to be fertilized.

Fertilized eggs differ from unfertilized eggs in that the permeabil-

ity of the membrane is increased, as is shown by increased use of

oxygen after fertilization in some eggs, by increased escape of CO2

and other substances, by more rapid transfer of water by osmosis,

by taking up of intra-vitam stains, etc. Fertilized egg cytoplasm is

less fluid than before fertilization—which is interpreted as a gelation

phenomenon. Chemically the fertilized egg loses the power to pro-

duce the substance that causes agglutination of the spermatozoa.

The activating effect of the sperm upon the egg consists physio-

logically of two different and progressive parts; (1) the cortical

changes which usually closely follow upon penetration, but which in

some types of eggs may be shown not to depend on penetration; and

(2) the internal progressive series of processes which seem to be

completed about the time of the union of the nuclei. In this internal

work does the sperm activate the egg by means of a substance, which

AMERICAN MICROSCOPICAL SOCIETY 253

itself gradually releases? Or does it progressively activate some

substance already in the egg?

In Chapter VII this special problem of activation of the egg is

taken up in detail, and may be considered in three phases; the produc-

tion of the changes at the surface of the egg in the plasma membrane

and the cortex; second, the activation of the internal protoplasm;

and finally the operations of the combined nuclei, leading up to

karyokinesis and cleavage.

The evidence seems conclusive that the egg produces and posses-

ses all the activating substances. The spermatozoon merely releases

these or causes their development, and does not furnish the substance

itself. This is evidenced by the fact that polyspermy does not in

any way accelerate the process. The author’s view may be summar-

ized as follows:

First interaction—egg on sperm: The egg secretes in the process

of maturing substance whose first manifestation is its agglutinizing

or binding effect on the sperm. This, supplemented by the thigmo-

taxis of the sperm, secures contact—and penetration of the egg by

the sperm.

Second interaction—sperm on cortical portion of egg: Upon

contact and penetration by the sperm there is a cortical change

in the egg, which prevents further reaction of the egg to other sper-

matozoa. In some eggs this shows as an elevation of a “‘fertilization

membrane.”’ This starts at the point of impact and proceeds at a

rapid, but measurable and varied, rate around the egg. Beneath

this membrane, however, in the cortex there is a ‘‘wave of negativ-

ity” that is more rapid than the membrane formation and makes the

whole cortex immune to further sperm action sometime before the

membrane is elevated. This seems to be the really significant reac-

tion.

The author believes that the essential activating substance which

produces this cortical fertilization change in the egg is the same as

that which produced the agglutinating of the sperm. He calls this

substance ‘‘fertilizin.”” The sperm introduces a substance which

releases the activities of the fertilizin. This produces the instantan-

eous change in the cortex. The identity of the fertilizin with the

agglutinating substance is based upon the following considerations.

Eggs before beginning the secretion of the agglutinizing substance

254 NOTES AND REVIEWS

cannot be fertilized; eggs after fertilization are incapable of reaction

to entering sperm, and in such eggs all the agglutinating substance

also disappears; eggs artificially activated likewise cease to produce

agglutinizing substance; washings which cause a decline in the pres-

ence of this substance cause the decline also of power of being ferti-

lized. Thus the sperm agglutination and the fertilization activation

are completely parallel and coincident, and hence are either produced

by one substance with a dual action or by two substances most

remarkably yoked. The former is the simpler hypothesis.

Eggs which have been producing abundant fertilizin, sufficient to

charge many hundred times their own bulk of sea-water, immediately

cease after fertilization, and the eggs no longer agglutinize sperma-

tozoa nor react tothem. The author believes this does not mean that

the power of secretion is merely exhausted, but that the entrance

of the sperm causes this agglutinating side chain of the fertilizin

to combine with some substance, and thus the changed cortex becomes

completely incapable of further sperm reaction. This substance

he calls anti-fertilizin.

The existence of such substance in the interior of the egg which

unites with and neutralizes fertilizin is shown by this experiment.

The fertilizin of maturing eggs may be collected in sea-water. Then

the eggs themselves may be repeatedly washed until they almost

cease to produce fertilizin. If these washed eggs be shaken to pieces

in the sea water containing their own fertilizin the latter is neutral-

ized. Normally it would have kept for considerable periods.

Fertilizin then is necessary for fertilization. As soon as fertilization

is effected it disappears from the cortex and further fertilization is

impossible. It has been shown that a concentration of egg fertilizin

may produce parthenogenesis in eggs of the same species. On the

other hand sperm extracts will not activate eggs.

Third interaction—the cortex and sperm with the interior: The

activation of the deeper cytoplasm might be effected by the advanc-

ing sperm, or progressively from the changed cortex, or both.

Spermatozoa that succeed in penetrating into immature eggs or into

eggs already reacting have no effect on the deeper protoplasm.

Portions of eggs in a state to be fertilized can themselves be fertilized.

The author, quoting from work of Chambers yet unpublished, cites

experiments showing that dissections of fertilizable eggs containing

AMERICAN MICROSCOPICAL SOCIETY 255

the internal protoplasm alone can not be fertilized. Whereas if this

inner protoplasm remains connected with cortical material the mass

is fertilizable, and the perfection of the latter events is a function of

the amount of cortical material present. This determination seems

crucial in respect to the essential soundness of distinguishing the

superficial from the deeper phenomena, and of considering the

processes in the cortex rather than the spermatozoon itself as the

activating agency in the deeper protoplasm.

It is suggested that this fertilization product in the cortex may

exert a ferment-like action, or bodies formerly solid may become

liquified, and thus penetrate into the depths of the egg. These pro-

blems are yet obscure. Evidently the cortical combinations release

substances that produce metabolic changes, including increased

consumption of oxygen, and the initiation of development.

Fourth interaction—of the nuclei and the cytoplasm: Little can be

said at present relative to this. The action that brings the two nuclei

together the author holds to be merely the parallel effect of the

cytoplasmic stresses working upon both, rather than to any attraction

between the nuclei themselves. The supreme problem in this connec-

tion is the coérdination of the various factors and processes that lead

up to nuclear division. It is a matter of timing these two nuclei with

quite diverse history—and both of these to the cytoplasm. In this

process the leading role is taken by the sperm nucleus. The intricate

character of this timing process is realized by recalling the various

periods in which the sperm enters in various eggs, in relation to the

maturation divisions of the egg itself: it may enter during the resting

stage following completed maturation; or in the midst of the matura-

tion mitosis; or before the process is well under way. This tuning or

timing process may well be considered a mutual one. It is not

unreasonable to suppose, with the author, that the sperm nucleus

has been “fertilized,” and thus rendered physiologically potent as

well as synchronized by its experiences in the cortex and thus made

relatively dominant in the later stages of internal reaction. The

sperm aster would be an instance of this increased rdle.

Chapter VI deals with problems of specificity. This means the

investigation of the question as to whether ova and sperm, with this

well analyzed group of fertilization interactions we have been study-

256 NOTES AND REVIEWS

ing, are thus attuned to each other by such specifically exact adjust-

ments that they are limited to each other. There are two possible

aspects of this: (1) Can sperm penetrate other kinds of cell beside the

ovum? or (2) Can sperm and eggs of different species of organisms

unite and effect fertilization?

In respect to the first problem some claims have been made of

sperm penetrating epithelial cells of the uterus, and even cleavage

cells of the developing blastula. These findings are not confirmed

and are in great doubt. Numerous negative findings are recorded

where the sperm have abundant opportunity to penetrate the epithe-

lia of oviducts. Furthermore, the agglutinating product of eggs is

specific. No other body fluid, secretion, nor tissue-extract is capable

of agglutinating the sperm. We may say then that eggs and sperm

seem to be utterly specific from the point of view of their tissue

differentiation.

The specificity of the fertilization can be advantageously studied

in those animals in which fertilization is external—as echinoderms,

teleosts, and amphibia. The studies involve the crossing of different

species, genera, classes, and even phyla. Attempted self-fertilization

in those forms which usually cross fertilize is also a fruitful field for

experiment. Incompatibility—an inverse measure of specificity—

may show itself in very varied degrees. In certain combinations,

as some species of frogs, the eggs do not react at all to the foreign

sperm. In other animals, foreign sperm may start the cortical

changes but be unable to penetrate. This is often the case in crossing

different genera, classes, etc. In some cases they may penetrate and

fail to activate the deeper protoplasm or unite the nuclei. In some

cases where the nuclei unite, the sperm chromatin may be eliminated

during cleavage, as between some species of Echinus and in crosses

of Arbacia with Echinus. In these cases the resulting embryos have

purely maternal characteristics. Even in cases where the male

chromosomes are retained the development may be partial or other-

wise abnormal. In some instances there is complete and normal

development, but the hybrid itself is sterile. The hybrids from

certain crosses seem perfectly normal and fertile. This makes a most

instructive series showing all degrees of compatibility from perfect to

zero. It expresses itself in the possibility or ease of fertilization; in

the completeness of the reaction; in the tolerance of the chromosomes;

AMERICAN MICROSCOPICAL SOCIETY 257

in the initiation of development; in the stage to which it may go; in

the viability, the normality, and the fertility of the offspring.

From a survey of the numerous experiments with eggs and sperms

of echinoderms, fishes and amphibians—the author concludes that

there are both specific and non-specific factors in fertilization. These

may be outlined as follows:—

1. There is some specificity in the agglutinating effect of egg

secretions. Some sperm Lave been shown to be uninfluenced by

heterologous egg secretions. More investigation is needed on this

point.

2. There is unquestiona>ly specific resistence in the normal corti-

cal reaction of eggs to heterologous sperm. Here is the most common

block on fertilization. It very generally exists in crosses outside the

species and increases with the remotencss. It is found, however, in

self-incompatible hermaphrodites. It may be overcome by staling

and by the use of chemicals. While there may be physical elements

in this cortical adaptation, whereby homologous sperm is favored and

heterologous discouraged, the chief factor is almost surely a chemical

one.

3. The next stages of activation seem little or not at all specific.

Any spermatozoon, apparently, after having produced the cortical

reaction may pass on and call forth the same general internal events

as the homologous sperm. If chemical means have been used to

secure the entrance of the sperm, these can still pass into the cyto-

plasm and accomplish union. This has been done by means of

Mollusk sperm in Echinoderm eggs.

4. Another block, which is of a specific nature, appears in the later

stages of activation after the union of the nuclei. This is shown by the

elimination of the male chromatin. Clearly similar incompatibility

might exist, quite equal to the prevention of normal development,

which might still fall short of this elimination. The author believes

that the whole problem of specificity in fertilization is closely related

to that of sperm agglutination by the egg secretions, which has been

shown to be completely parallel to the cortical reaction of eggs in

fertilization.

The reviewer has undertaken thus to give a somewhat extended

account of the argument in this very suggestive book because the

book itself does so well what the Transactions have been trying to do

258 NOTES AND REVIEWS

for the members of the Society by the ‘Summaries of Progress” that

have been given from time totime. The necessary brevity of such a

exposition is a shortcoming; but possibly even this may guide the

reader to the book. The whole discussion illustrates most brilliantly

the method of approximation seen in physiological analysis at its

best.

The Problem of Fertilization, by F. R. Lillie. 278 pages, University of Chicago Press, 1919.

Price $1.75 net.

APPLIED EUGENICS

Popenoe and Johnson have undertaken in this book to magnify

the application of the principles of genetics to human society rather

than to discuss at length the biological foundations of inheritance.

In the study of human biology we are quite disposed to ignore the

fact that we cannot always judge the germ plasm of an individual

by his own personal accomplishments. The authors impress well the

fundamental fact that we must get a germinal rather than a mere

cultural basis for human improvement, if we would encourage the

production of superior and discourage that of inferior persons. A

eugenically superior person is defined as one ‘‘who has, to a greater

degree than the average, the germinal basis of the following character-

istics:—to live past maturity, to reproduce adequately, to live

happily and to make contributions to the productivitv, happiness,

and progress of society.”

The authors leave to others the statement of the problems of

genetics underlying eugenics, and concern themselves much more

largely in consequence with the applied aspects of the question. . The

chapter headings sufficiently indicate the thoroughness with which

the subject is presented: Nature or Nurture? Modification of the

Germ Plasm; Differences among Men; Inheritance of Mental Traits;

Laws of Heredity; Natural Selection; Origin and Growth of the

Eugenic Movement; Desirability of Restrictive Eugenics; The Dys-

genic Classes; Methods of Restriction; Improvement of Sexual

Selection; Increasing the Marriage Rate of the Superior; The Color

Line; Immigration; War; Genealogy and Eugenics; The Eugenic

Aspect of such Specific Reforms as Taxation, Rural Movement,

Democracy, Socialism, Child Labor, Compulsory Education, Voca-

tional Guidance and Training, Minimum Wage, Mother’s Pensions,

AMERICAN MICROSCOPICAL SOCIETY 259

Housing, Feminism, Sex Hygiene Movement, Trades Unionism,

Prohibition, and the like; Religion and Eugenics; Eugenics and

Euthenics.

This book is a thoroly well organized and well-reasoned contribu-

tion to a subject of immense importance and timeliness. It is sure

to be much used.

Applied Eugenics, by Paul Popenoe and R. H. Johnson, 459 pages. The Macmillan Conpany, 1918.

THE CAUSES AND COURSE OF ORGANIC EVOLUTION

The last few years have seen a revival of interest in the task of

furnishing a statement of the problems and progress of general

evolution. While perhaps none of these except that of Osborne

makes a notably original contribution to this synthesis, no such

attempt is ever without great interest to the student of life.

The author of the book under review calls it a “Study in Bio-

energics.”’ He says that energy, continuity, and evolution may be

considered the triune key-note of the volume. His early chapters

have to do with “Ether and Energy in Evolution of Matter,” ‘Rela-

tion of Inorganic to Organic Bodies,” ‘‘Relations and Transformations

of Energy,” and “Energies of the Organic World.”

In the spirit of this idea that evolution is to be conceived primarily

as transformations of energy in relation to ether, the author under-

takes to arrange an ascending series of energies under the two heads

of inorganic (crystalloid) energies and organic (or colloid). Under

the former he grades heat, light, chemical activity, and electricity

as progressive manifestations, and he deems the physical states of

matter—gaseous, liquid, viscous, and solid—as parallel with, and the

result of, these progressive transformations in energy. Between the

inorganic and organic he conceives a “‘transition’”’ energy which he

calls ‘‘duplo-electric.”” The distinctive organic energies he names

biotic, cognitic, cogitic, and spiritic. Parallel with the evolution

of these types of energy we have the specialized manifestations of

matter in the ascending scale of living objects, as protoplasmic,

nuclear-chromatin, and nerve cell substance (‘‘neuratin’”’). Later

in the volume the author gives specific chapters to the discussion of

what he conceives to be the essential nature of each of these, their

relation to one another and to the “inorganic energies”’ of heat, light,

260 NOTES AND REVIEWS

chemical affinities and electricity. The author continually uses in

this connection a conception like this: the progress in the realization

of these energies is marked by increased and “more condensed energy

activities.”’ Great ingenuity is shown in correlating these energies,

the materials they are associated with, and their various manifesta-

tions. On the one hand a tremendous encyclopedic amount of

chemical, physical, and biological data are thus correlated; on the

other the definiteness of these correlations seem at times naively

forced and fanciful—and often ponderously worded.

The active causes of organic evolution are mentioned as (1) hered-

ity, (2) Environment; (3) Proenvironment; (4) Selection, and

(5) Reproduction. Of these the author regards his “law of proen-

vironment” as a distinctive contribution. He defines this as the

“capacity of organized beings of being stimulated by and then posi-

tively growing or moving, in part or in whole, toward an environment

that represents the satisfying resultant or mean between all of the

environal stimuli by which they are surrounded’; ‘‘the correlated

resultant response by any body to the summated correlation of

stimulatory action, that leads to a temporarily satisfied state.” So

far as the writer can see this “‘law” is only a roundabout statement

of the idea of ontogenetic recapitulation (a form of inheritance),

plus a measure of the idea of orthogenesis, and possibly a dash of

determinism. It seems to say little more than that responses are

really adaptive and that they seem to satisfy the organism before the

response can actually bring about the adaptation to which the com-

pleted response ultimately leads.

Next follow a chapter on the origin of sexuality, three on the

evolution of plants, and five on the evolution of animals. The last

third of the book is given to a discussion of human evolution, the

later chapters being given to a consideration of “Morals as a Factor

in Organic Evolution,” “Religion as a Factor in Human Evolution,”

“History of Religious Evolution,” “Probable Future Advances in

Evolution.”

As protoplasm is the material formed by biotic energy and is its

avenue of expression; and chromatin the product and vehicle of

cognitic energy; and neuratin the foundation of the cogitic energy of

the nerve cells—so hypothetical ‘“‘spiritin’’ is conceived to be the

AMERICAN MICROSCOPICAL SOCIETY 261

material concentrate which is at once the product and the mechanism

of “‘spiritic energy” which inspires those specialized phases of per-

sonality which are more social, sacrificial, moral, religious—counsels

of perfection—the partial qualities of present men, the prime qualities

of the superman.

Idealized and even fantastic as some of the author’s restatements

and interpretation of the scientific data may seem, the reader is

certainly made to feel the writer’s sense of continuity and inclusive-

ness of evolution, as well as the remarkable function which

imagination must play in any such enterprize of synthesizing and

actually including all the higher human states as truly as those more

elemental forms of energy of which we usually make so much.

The Causes and Course of Evolution, by J. M. Macfarlane. Pages 875. Illustrated. The Mac-

millan Company, New York, 1918. Price $4.00.

TRANSACTIONS

American Microscopical Society

(Published in Quarterly Instalments)

Vol. XXXVIII OCTOBER, 1919 No. 4

A PECULIAR ENTOMOPHTHOROUS FUNGUS

E. M. GILBERT

The writer has for some time been interested in the collection

and study of fungi which are found under conditions of a more or less

aquatic nature. In this connection a study has been made of the

fungi found on fern prothallia grown in water cultures or on moist

sphagnum. Both the sphagnum and liquid cultures were carefully

sterilized before the sowing of the spores took place.

Among the fungi which from time to time made their appearance

in these cultures was one which seemed to all appearances to be a

vigorous parasite, and an effort was at once made to isolate it for

further study and identification. Thaxter’s Potato-hard agar, to

which had been added a small quantity of Lofflund’s Malt Extract,

was poured into sterile Petri dishes and dilution transfers were then

made, giving in two days a vigorous growth of the fungus. Pure

cultures were easily obtained as it was found that the spores of the

fungus were thrown to a considerable distance and by means of the

binocular microscope it was possible to pick out individual spores

which could then be transferred to test tubes containing media and

in a few days a number of pure cultures were available.

The preliminary study seemed to indicate that the fungus was of

an Entomophthorous nature and an effort was then made to find the

insect upon which it may have been growing. No infections were

secured upon any of the insects found in the fern cultures nor upon

any of the various insects found in the greenhouse. No successful

infections were secured when vigorous fern cultures were inoculated,

but it was found that the fungus would grow on dying fern prothallia

and upon prothallia which were infected by other fungi. The evi-

dence so far collected seems to indicate that the fungus, altho seem-

264 E. M. GILBERT

ingly very much like Empusa in morphological characteristics, is of

a decided saprophytic nature as it has been possible to grow it on

many of the common fungal media such as potato-hard agar, oatmeal

agar, rice agar, pumpkin agar, but best results have been obtained

on agar containing the Malt-soup or a beef extract.

Other investigators have observed a saprophytic condition in

members of the Entomophthorales. Mr. Torrey of the Storrs Ex-

periment Station, Storrs, Connecticut, has made a study of such a

fungus which he has described in a paper, I believe now in print.

Molliard (13) describes E. henrici originally obtained as a parasite on

Culex pipiens, which he has found capable of growing on the sterilized

grub of Euchelia jacobaeae, on sterilized ox-liver and even on vege-

table material such as sterilized carrot. It was found, however,

that the growth on the vegetable substratum was not as vigorous as

that obtained on animal tissue. These observations indicate that

it may well be possible that other members of the group may be

able to live at least in part as saprophytes.

THE FUNGUS

The mycelium grows very rapidly and at the end of from 48

to 72 hours forms a thin, compact growth on the surface of the

medium. No haustoria or rhizoidal growth has been found and there

is very little penetration of the substance upon which the fungus

may be growing. The hyphae branch profusely and soon become

septate with cells of varying length. The individual cells compare

favorably with those described by Thaxter (19) and Olive (16) for

Empusa, but contain a greater number of vacuoles and are not as a

rule as irregular in shape (Fig. 1). The cytoplasm is of a very heavy

granular nature and does not as a rule contain the conspicuous fat

bodies described by these authors. This of course may in part be

due to the fact that the media used differ greatly in food content

from the bodies of insects upon which the Empusas grow. Fat or oil

bodies are more often found in the older hyphal cells and in the

mature conidia.

The shape and size of individual cells vary greatly, dependent

upon the nature of the medium upon which the fungus is growing.

On a medium poor in food material the cells are more elongate and

A PECULIAR ENTOMOPHTHORUS FUNGUS 265

narrow in diameter, while on a rich substratum they are thicker,

shorter, and less vacuolate.

REPRODUCTION

At the end of from 36 to 48 hours the conidiophores begin to make

their appearance in considerable numbers. These may arise from

any portion of the hyphae, but usually arise from the terminal cells.

Search has been made for the hyphal bodies described by Thaxter (19)

and Olive (16) but no cells quite comparable to these have been found,

although it is evident at times that the cells which give rise to the

conidiophores are filled with a denser cytoplasm and are often more

irregular in shape than neighboring cells. Nothing comparable to

the sclerotia described by Sorokin (17, 18) have been found in any of

these cultures.

The conidiophores arise as branches from the cell and are usually

simple, each producing a single conidium (Figs. 2, 3), but many

cases of compound conidiophores are found, in some instances quite

comparable to those described by Thaxter for Empusa occidentalis

and Empusa A phidis (Figs. 6-9).

The conidiophore becomes club-shaped and filled with a very

heavy granular cytoplasm which at once distinguishes it from any

of the cells of the vegetative hyphae. The apical portion soon

expands into a “basidium”’ which finally reaches about the diameter

of the mature conidium. By this time the basal portion of the

conidiophore has become greatly vacuolated and there seems to be a

decided movement of the cytoplasm into the rounded upper end. It

has not been possible to definitely decide just what takes place during

the next stage but a columella like structure soon makes its appear-

ance, cutting off the enlarged portion of the basidium, and within

this cell a membrane is laid down to form the wall of the single spore.

Bigs: 5,10; 11.

A portion of the content of the basidium continues to pass into

the maturing conidium which finally becomes filled with a very

dense granular cytoplasm, in which appear at times a few fat bodies.

During this later stage the portion of the conidium which is in contact

with the ‘‘columella’’ becomes decidedly conical with the apex of the

cone usually pressed against the columella. The cytoplasm within

the basidium at this stage is decidedly hyaline and at times appears

to contain little or no cytoplasm.

266 E. M. GILBERT

The process by which the basidium ruptures and projects the

conidium is not fully understood. Many instances have been found

where it appears as if the pointed portion of the conidium tends to

weaken or pierce the columella of the basidium which is continually

becoming more turgid, due to the intake of water, and finally the

pressure becomes so great that the entire end of the basidium is torn

asunder, thus discharging the conidium with such force that it is

often thrown to a distance of 65 mm.

A portion of the content of the basidium is probably thrown with

the conidium and it seemingly is due to this material that the coni-

dium will readily adhere to any substance with which it may come

in contact. Although this seems to be the usual procedure, other

cases have been observed where it appears as if the basidial wall

ruptures without any damage to the columella.

THE CONIDIA

The mature conidium is perfectly spherical except for a con-

spicuous “‘appiculus” found at the point of contact with the columella.

The cytoplasm is usually quite dense, finely granular, with an occa-

sional fat body. The primary conidia have a diameter varying from

48y-—60u, the secondary conidia average 35u-40y, while the tertiary

conidia at times have a diameter of not more than 20u. The secon-

dary and tertiary conidia are often characterized by the presence of

a very large vacuole and conspicuous fat bodies are at times also

apparent.

GERMINATION OF THE CONIDIA

When a conidium falls upon a substratum containing some

moisture, it germinates in from 6-12 hours, putting out from one to

four germ tubes which in a very short time develop into the typical

septate mycelium previously described. Fig. 16. If, however, a

conidium falls upon a surface free from moisture, it at once develops

a very short tube, often less than one-tenth as great as the diameter

of the spore, at the end of which is produced a secondary conidium

averaging about two-thirds the diameter of the primary spore.

Figs. 18, 22. This secondary conidium is formed like the primary

spore and is discharged in the same manner, and may now produce

either a mycelium or a “tertiary” spore, dependent upon the nature

of the substratum.

A PECULIAR ENTOMOPHTHORUS FUNGUS 267

In some cultures it has been found that the primary conidia do

not germinate if discharged upon an unfavorable substance, but

instead there appears a slight thickening of the spore wall, while at

the same time the contents become decidedly yellowish in color.

These were at first thought to be resting spores but it has so far been

impossible to obtain any evidence of germination.

In a few rare cases the germ tubes continue to elongate for a

time and then produce a basidium and a secondary conidium. In

such cases the secondary conidium is of a smaller size than the nor-

mal secondary spore, probably due to the fact that much of the

content of the primary spore was used in formation of the hyphae.

Figs. 19, 20.

University of Wisconsin.

BIBLIOGRAPHY

1. Arruur, J. C.

1886. Onanew larvae Entomophthora. Bot. Gaz. 1/: 14.

1886. Entomophthora Phytonomi. Bull. N. Y. Agr. Exp. Station, Jan.

3. Bessey, C. E.

1883. A new species of insect-destroying fungus. Amer. Naturalist, 17: 1280

and 1286.

4, BREFELD, O.

1870. Entwickelungsgeschichte der Empusa Muscae and Empusa radicans. Bot.

Zeit. 28: 177 and 161.

1871. Untersuchungen ueber die Entwicklung der Empusa Muscae und E. radi-

cans. Abhandlung der Naturforschenden Gesellschaft zu Halle, Bd.

Mil, Heft:1; p. 1:

————

1877. Ueber die Entomophthoreen und ihre Verwandten. Bot. Zeit. 35: 345

and 368.

1881. Entomophthora radicans. Botanische Untersuchungen ueber Schimmel-

pilze, Heft IV, p. 97. Leipzig.

1884. Conidiobolus utriculosus and C. minor. Botanische Untersuchungen ueber

Schimmelpilze, Heft VI, p. 35. Leipzig.

9. Conn, F.

1875. Ueber eine neue Pilzkrankheit der Erdraupen. Beitrage zur Biologie der

Pflanzen, Bd. I, Heft 1, p. 58.

268 £. M. GILBERT

10.

11.

12.

13:

14.

15:

16.

18.

19:

20.

Cornu, M.

1873. Note sur une nouvelle espece d’Entomophthora. Bulletin de la Societe

Botanique de France, 20: 189.

Ema, E.

1886. Basidiobolus, eine neue Gattung der Entomophthoraceen. Beitrage zur

Biologie der Pflanzen, Bd. IV, Heft. 2, p. 181.

FRESENIUS, G.

1856. Notiz, Insekten-Pilze betreffend. Bot. Zeit. 14: 882.

Mo ttitiaArp, M.

1918. Saprophytic life of an Entomophthora. Comptes Rendus 167: 958-960.

NATURE.

1919. Vol. 102: 309. January 2.

NowakowskI, L.

1887. Die Copulation einiger Entomophthoreen. Bot. Zeit. 35: 217.

OttveE, E. W.

1906. Cytological studies on the Entomophthorineae. Bot. Gaz. 41: 192, 229.

Sorokin, H.

1876. Vorliufige Mittheilung iiber einige neue Entomophthora-Gattungen.

Hedwigia, 15: 146.

Ueber zwei neue Entomophthora-Arten. Beitrage zur Biologie der Pflanzen,

Band II, Heft 3, p. 387.

THAXTER, R.

1888. The Entomophthoreae of the United States. Boston Soc. of Nat. Hist.

Memoirs, 4: 133-201. With plates.

Winter, G.

1881. Zweineue Entomophthoreen-Formen. Bot. Centralbl. 5: pt.2: 62.

A PECULIAR ENTOMOPHTHORUS FUNGUS 269

EXPLANATION OF PLATES (XXVII—XXVITI)

All figures were drawn with the aid of the camera lucida, with a Leitz No. 3 ocular

and Leitz No. 6 objective.

Plate XXVII

Fig. 1. Typical cells from mycelium grown on agar containing beef extract.

Fig. 2. Early stage in formation of conidiophore.

Fig. 3. Conidiophore separated from balance of mycelium by cell wall.

Fig. 4. Coniodiophore with dense cytoplasm gathered at apex which is beginning to

increase in size.

Fig. 5. Terminal portion of conidiophore fully enlarged and ‘‘columella’”’ partly

completed.

Figs. 6, 7,8, and 9. Abnormal types of conidiophores which however produce typical

conidia.

PLATE XXVIII

Fig. 10. Upper portion of conidiophore, showing ‘‘columella”’ and also indications of

spore wall.

Fig. 11. Conidial wall completely laid down. At this stage the columella usually forms

an indentation in the maturing spore.

Fig. 12. Slightly later stage. The ‘‘appiculus” is in process of development and has

forced the columella backward into the basidium.

Figs. 13 and 14. Fully matured conidia still attached to basidium which at this stage

contains a very small amount of cytoplasm.

Fig. 15. Primary conidium showing heavy granular appearance.

Fig. 16. Germination of primary spore sown on agar containing Malt-soup extract.

Fig. 17. Germination of primary spore sown on potato-hard agar (sown at same time

as spore in Fig. 16.)

Fig. 18. Early stage in formation of secondary spore.

Figs. 19 and 20. Abnormal formation of secondary spore. In each case a conidiophore

has been formed.

Fig. 21. Germination of secondary spore.

Fig. 22. Formation of tertiary spore by secondary spore.

Fig. 23. Germination of tertiary spore.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL SOCIETY,

VOL. XXXVIII

BEATE XEXViIL GILBERT

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL SOCIETY,

VOL. XXXVIII

PLATE XXVIII GILBERT

THE DISTRIBUTION OF THE ARCHEGONIA AND THE

ANTHERIDIA ON THE PROTHALLIA OF SOME

HOMOSPOROUS LEPTOSPORANGIATE FERNS

W. N. STE

It is a well-known fact that in the ordinary Polypodiaceae, the

archegonia are formed exclusively on the so-called cushion and

directly back of the apical notch.

Usually the antheridia are pro-

duced on the posterior portion

of the prothallium, especially

among the rhizoids. In some

species antheridia are produced

also on the lobes and the mar-

gins of the prothallium. The

small ‘‘male’”’ prothallia are fre-

quently covered with antheridia,

but under favorable conditions

of nutrition, as Miss Wuist (1910)

has shown, become monoecious.

From some cultures of Pteris

aqilina L. in which the prothallia

were crowded the majority were

removed by the writer, and it

was found that the smaller re-

maining prothallia bearing only

antheridia assumed the typical

heart shape and formed also Fig. 1. A prothallium of Pteris

archegonia as shown in Fig. 1. *#élina. 2, oe

: eine bearing portion. The archegonia back

In this case the original anthe- of the apical notch and the antheridia

ridial bearing portion (a) canstill are diagrammatically represented.

be readily recognized. x25.

In the Osmundaceae the archegonia are produced on the sides of

the “‘mid-rib” which in Osmunda regalis is very conspicuous. On

i arig

252 W. N. STEIL

the younger prothallia a single row of archegonia is usually present

on each side of the mid-rib and extending from the apical notch to

the posterior part of the prothallium where many antheridia are

borne, although a large number are frequently produced on the lobes.

On the older prothallia numerous archegonia are formed along the

sides of the mid-rib. The distribution and the development of the

sex organs of Osmunda regalis were first described by Kny (1872).

20 4@0:

Be 0%

bo,

'a,0°O

= °

20%

Fig. 2. Aprothallium of Pteris ensiformis var. Victoria, showing archegonia

entirely surrounded by antheridia. The sex organs are diagrammatically

represented. 12.5.

The writer found a peculiar arrangement of the sex organs on the

prothallia of Pteris ensiformis Burn. var. victoria. The prothallium

in this species produces a prominent and elongated cushion. The

archegonia, however, occupy only the highest portion of the cushion.

In some instances a few archegonia are developed directly back of

the apical notch among numerous antheridia which are always pro-

duced on this portion of the prothallium of the Pferis species. Many

antheridia are also formed on the lower portion of the cushion

and on the posterior end of the prothallium. The archegonia are

thus wholly surrounded by antheridia (Figure 2). A large number

of the prothallia in. some of the cultures produced antheridia

but in no case archegonia, on both surfaces. Some of the pro-

thallia assumed a nearly vertical position. The two sides of the

HOMOSPOROUS LEPTOSPORANGIATE FERNS 213

prothallia were, therefore, almost equally illuminated, and in conse-

quence dorsi-ventrality was not completely established. Rhizoids

and antheridia were, hence, formed on both surfaces.

In some cases the small Stender dishes, used for the cultural

work, were only about half filled with sphagnum saturated with

a nutrient solution and prothallia of several species were grown on

the substratum. Antheridia and archegonia were produced, in con-

sequence of the illumination thus secured, on both surfaces of the

prothallia. The same results were obtained by Pierce (1906) who

grew the prothallia on a clinostat.

It has been frequently demonstrated that a sufficient reduction

in the amount of light inhibits the formation of heart-shaped pro-

‘thallia and in consequence archegonia are never produced. If '

favorable cultural conditions are maintained, prothallia may be

grown in weak light, and for an indefinite period of time only anther-

idia will be developed. If the illumination is sufficiently strong

for the formation of archegonia, such sex organs will develop with the

continued growth of the prothallium provided fertilization is pre-

vented. The prothallia of Osmunda regalis were grown under these

conditions for about a year and a half. On one of the prothallia,

thus produced, approximately a thousand archegonia were counted

(Steil, 1918).

University of Wisconsin,

Madison, Wisconsin.

274 W. N. STEIL

BIBLIOGRAPHY

Kny, L.

1872. Beitrage zur Entwickelungsgeschichte der Farnkrauter. I, Osmunda

regalis. Pringshs Jahrb. f. wiss. Bot. VIII, 1-16.

PrercE, J. C.

1906. Studies of Irritability in Plants. Ann. Bot. 20: 449-465.

Wuist, E. D.

1910. The Physiological Conditions for the Development of Monoecious Pro-

thallia in Onoclea Struthiopteris. Bot. Gaz. 49: 216-218.

Streit, W. N.

1918. Studies of Some New Cases of Apogamy in Ferns. Bull. Torr. Bot. Club

45: 93-108. Pls. 4,5.

NEW SPECIES OF WATER MITES OF THE

GENUS ARRHENURUS

RutH MarsHALL

About ninety genera of Hydrachnidae are now recognized, with

some eight hundred species. About one-fourth of these species

belong to the single genus Arrhenurus. Fifty-five have been des-

cribed for North America, chiefly from the upper Mississippi valley.

This paper adds one new species.

The hydrachnid fauna of South America has received little

attention. Only eleven species have been described, of which five

are for the females only. Dr. F. Koenike, in two papers (1894,

1905), published descriptions of two species (A. corniger, A. ludifica-

tor) found in material sent to him from Brazil. Dr. C. Ribago (1902)

described a single species from Colombia (A. oxyurus). Dr. E. von

Daday (1905) described seven new species from material collected in

Paraguay; these were designated A. anisitsi, A. apertus, A. meri-

dionalis, A. multangulus, A. propinquus, A. uncatus, A. trichoporus.

Dr. C. Walter, in a paper published in 1912, described one new species

(A. fuhrmanai), from Colombia. The present paper adds six new

species.

Material from Asia has been very scanty. Twenty-two species of

Arrhenuri have been recorded; of these eight are from Asia Minor,

mostly species found also in Europe. The remaining species have

been found in the islands of Ceylon, Java and Sumatra. This paper

adds two new species from China.

The author has been very fortunate in securing the material for

the descriptions of the nine new species of Arrhenuri included in this

paper, and thanks are extended to the collectors who generously

contributed it. The greater part of the material was found in

collections made in northern South America by the late Harriet B.

Merrill, in 1908 and 1909, and now in the possession of Dr. E. A.

Birge, of the University of Wisconsin, who kindly permitted the

author to sort out the water mites. Professor A. S. Pearse, of the

275

276 RUTH MARSHALL

University of Wisconsin, contributed material from Venezuela.

Mr. C. Juday, of the Wisconsin Natural History Survey, gave some

material in his possession which had been collected by Professor

N. Gist Gee, of Soochaw, China. Dr. R. A. Muttkowski sent

material found by him in the lakes at Madison, Wisconsin, and which

contained one new Arrhenurus.

Arrhenurus serratus nov. spec.

Pl. XXIX, Figs. 1-7

In form this mite resembles A. brachyurus Viets (1914), found in

Germany. The latter, however, is shown without a petiole, a con-

spicuous feature of the new species. The enclosed dorsal area is

large and runs over on to the small appendix. The petiole is a

long, slim transparent structure with an upward curve in its posterior

half where it has a saw-toothed appearance. At its base, on the

ventral side of the appendix, there are two saber-like bristles. There

is a delicate hyaline appendage and numerous stout hairs on the

appendix, with several smaller ones on the rest of the body. The

fourth joint of the fourth leg shows a well-developed spur with a few

short curved hairs at its end. The body measures 1.0 mm. without

the projecting petiole which measures 0.2 mm. The female has a

length of 1.3 mm.,and is ovateinform. The genital area is large and

the wing-shaped areas are broad and extend nearly straight outward

from the cleft. The color is olive green in preserved material.

Three males and four females were found in Lake Mendota, at

Madison, Wisconsin, June 18, 1915, by Dr. R. A. Muttkowski.

Arrhenurus asiaticus nov. spec.

Pl. XXIX, Figs. 8-10

In dorsal aspect this species bears a general resemblance to that of

the North American species A. montifer Marshall, and shows the

characteristics of the subgenus Micrurus in the stout form, small

enclosed dorsal area and short scalloped appendix with a medial

incision. The petiole is stout and turned abruptly upward and has

no hyaline appendage. The fourth leg lacks the spur on the fourth

joint, but this and the preceding segment have sharp points on the

distal ends. The palpi are stout. The color of the preserved speci-

min is pale blue green with brown mottles. The body length is

0.9 mm.

NEW SPECIES OF WATER MITES 277

The single male on which this description is based was found by

Mr. N. Gist Gee, of the University of Soochaw, China, in material

taken from canals and small lakes in the region.

Arrhenurus distinctus nov. spec.

Pl. XXX, Figs. 14-16

This form resembles A. orientalis Daday (1898), found in Ceylon.

The large and well-developed petiole has a similar form in the two

species, but in the related form it is more flaring at the end and

relatively larger. The new species has a longer body, the entire

length, including the petiole being 1.10 mm., the petiole alone being

0.75 mm. long. No trace of a hyaline appendage was found. There

is a well-developed spur on the fourth leg. The palpi are stout.

The stout body with the well-developed appendix having conspicuous

lateral projections directed outward, and the pair of sickle-shaped

projections within the dorsal enclosed area place the new species in

a well-defined group of the subgenus Arrhenurus noted by the author

in a former paper (1908). The color is a pale brown green.

A single male of this species was found with the preceding species

in the material from Soochaw, China.

Arrhenurus valencius nov. spec.

Pl. XXIX, Figs. 11-13

A single female from Lake Valencia, Venezuela (July 18, 1918),

sent to the author by Professor A. S. Pearse for identification proved

to be a new form and its description is now given. It resembles

A. multangulus Daday fem. from Paraguay, but is larger (1.53 mm.).

The large conical elevations on the dorsal side of the body which are

so conspicuous in both species do not have the same arrangement.

In the new species there are four large humps at the posterior end

of the body, while the anterior ones and those within the enclosed

dorsal area are small. The genital region is small and the wing-

shaped areas bend abruptly outward. The color of the specimen

is blue green.

Arrhenurus merrilli nov. spec.

Pl. XXX, Figs. 17-18

This species and the four which follow belong to the Merrill

collection. It is noteworthy that these five new species as well as

most of the other described South American Arrhenuri for which the

278 RUTH MARSHALL

males are known belong to the “long tailed” group, the subgenus

Megalurus.

A. merrilli is a small water mite, its total length being only 0.80

mm. It resembles the North American species A. manubriator

Marshall. The elevations on the body and appendix are only mode-

rately developed. The epimera end in blunt points. The line

enclosing the dorsal area runs over to the ventral side where it closes

at the narrow genital wings. There is a small spur on the fourth

segment of the fourth leg and segments two and three end in sharp

points. The color of the specimen is brownish green.

One male was found by Miss Merrill in a small clay puddle near

Marajo, Brazil, May 5, 1908.

Arrhenurus triconicus nov. spec.

Pl. XXX, Figs. 19-24

Abundant material was found for the study of thisspecies. It

resembles A. /udificator Koenike and A. uncatus Daday; these three

species, together with the following species and its related form, are

all characterized by the possession of a large conical elevation in the

middle of a long slim appendix, a feature which so far has been found

in only two others, the North American species A. petiolatus Piersig

and A. cornicularis Marshall. A. triconicus has also two small but

well-developed outstanding humps near the end of the appendix.

The line enclosing the dorsal area runs ventrally below the small

genital wings. The epimeral groups are close together; the first

and second develop horn-like projections as in the next species.

The entire length of the animal is 0.70 mm. The palpi are char-

acterized by an unusual development of the fourth segment.

The female of this species was identified. The body is obovate

and measures 0.50 mm. The epimera show the same tendency to

develop horns as in the male. The color is blue green.

Seventeen males and twenty females were found in Miss Merrill’s

‘ collections. These were taken in May, 1908, at Calama, Rio Made-

ria, and Marajo, Brazil; and in March, 1909, from canals near Christ’s

Church, Georgetown, British Guiana.

Arrhenurus epimerosus nov. spec.

Pl. XXXTI, Figs. 25-28

As noted in the preceding description, this species belongs to a

small and sharply defined gourp of the subgenus characteirzed by

NEW SPECIES OF WATER MITES 279

the development of a large conical hump near the base of the appen-

dix; like A. triconicus it also shows an unusual development of horn-

like extensions on the first two pairs of epimera, very striking in this

species in the case of the second pair. The latter feature, together

with the general form of the appendix, relates this species closely to

’ A. corniger Koenike. Fortunately the author is in possession of a

specimen which Dr. Koenike had kindly sent of his species and a

careful comparison of the two forms was possible. The new species

is smaller, measuring only 0.65 mm.; the appendix is slimmer and its

conical hump is larger and more anteriorally placed than in the

related form. The color is blue green.

Two males were found in Miss Merrill’s collections from Brazil

(Calama and Marajo, Lake Aray) in 1908.

Arrhenurus maderius nov. spec.

Pl. XXXTI, Figs. 29-32

The formation of humps on the body and appendix is characteris-

tic of several of the described species of South American Arrhenuri.

In this and the following species it is the body rather than the appen-

dix which has them. Herfe our large lateral elevations, two dorsal

and two posterior, besides two smaller ones by the eyes, give the

body an angular form. The dorsal enclosed area is without them;

its enclosing line runs ventrally over to the small genital wings.

The appendix is broad, scarcely as long as the body proper, and ends

in a scolloped border. (In one individual the end is more truncated

and the rounded corners more pronounced than is shown in Fig. 29.)

Near the end is a small but distinct peg-like petiole (P, Figs. 29, 30),

similar to one sometimes found in other males of the subgenus. The

palpi have a scanty patch of short fine hairs on the second segment.

There is a small spur on the fourth joint of the fourth leg. The

length of the entire body is 1.15 mm. The color is brown green in

preservation.

Two males of this species occur in collections made by Miss

Merrill in 1908, one from Rio Maderia, Brazil, the other from British

Guiana.

Arrhenurus quadricornicus nov. spec.

Pl. XXXI, Figs. 33-37

This is a very striking form, characterized by the enormous

development of horns on the body in both sexes. In the male there

280 RUTH MARSHALL

are four large curved ones, two anterior ones on the protuberances

over the eyes, and two lateral ones on elongated elevations. The

appendix is small at the base, increasing in width and thickness

toward the end, and free from conspicuous elevations. The fourth

segment of the fourth leg has a moderately long spur with a bunch

of long curved hairs. The entire length of the body, including the

anterior horns, is 1.30 mm.

In the female, besides the four horns, smaller but similarily placed,

there are two larger ones on the posterior corners of the body and four

small rounded humps, two within the enclosed dorsal area and two

at the extreme end. The palpi are somewhat unusual in form; the

second is very broad and bears a small patch of fine hairs on the

inner surface. The entire length of the body, including the horns, is

0.90 mm. The color is dark brownish green in preservation.

One male and one female were found in Miss Merrill’s collections

from Georgetown, British Guinana (canals near Christ’s Church),

March, 1909.

Lane Technical School, Chicago.

September 1, 1919.

SANNA M PWN

NEW SPECIES OF WATER MITES 281

EXPLANATION OF THE PLATES

PLATE XXIX

. Arrhenurus serratus, dorsal view.

. Arrhenurus serratus, ventral view of the appendix.

Arrhenurus serratus, lateral view.

. Arrhenurus serratus, left fourth leg, last three segments.

. Arrhenurus serratus, palpus.

. Arrhenurus serratus female, dorsal view.

. Arrhenurus serratus female, epimera.

. Arrhenurus asiaticus, dorsal view.

. Arrhenurus astaticus, ventral view of the end of the appendix.

. Arrhenurus asiaticus, lateral view.

. Arrhenurus valencius female, dorsal view.

. Arrhenurus valencius female, ventral view of the posterior end.

. Arrhenurus valencius female, palpus.

PLATE XXX

. Arrhenurus distinctus, dorsal view.

. Arrhenurus distinctus, ventral view of the appendix.

. Arrhenurus distinctus, lateral view.

. Arrhenurus merrilli, dorsal view.

. Arrhenurus merrilli, lateral view.

. Arrhenurus triconicus, dorsal view.

. Arrhenurus triconicus, lateral view.

. Arrhenurus triconicus, ventral view of the body.

. Arrhenurus triconicus, left palpus.

. Arrhenurus triconicus female, dorsal view.

. Arrhenurus triconicus female, epimera.

PLATE XXXI

. Arrhenurus epimerosus, dorsal view.

. Arrhenurus epimerosus, lateral view.

. Arrhenurus epimerosus, ventral view of the body.

. Arrhenurus epimerosus, left palpus.

. Arrhenurus maderius, dorsal view; P, petiole.

. Arrhenurus maderius, lateral view; P, petiole.

. Arrhenurus maderius, ventral view of the genital area and appendix.

. Arrhenurus maderius, right palpus.

. Arrhenurus quadricornicus, dorsal view.

. Arrhenurus quadricornicus, lateral view.

. Arrhenurus quadricornicus female, dorsal view.

. Arrhenurus duadricornicus female, ventral view.

. Arrhenurus quadricornicus female, right palpus.

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL SOCIETY,

VOL. XXXVIII

eee hy Oe

PLATE XXIX MARSHALL

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL SOCIETY,

VOL. XXXVIII

PLATE XXX MARSHALL

TRANSACTIONS OF THE AMERICAN MICROSCOPICAL SOCIETY,

VOL. XXXVIII

PLATE XXXI MARSHALL

DIATOMS—NEW GENERA AND SPECIES

By Frep B. TAyLor

The only catalogue of diatoms which can be regarded as exhaus-

tive, is De Toni’s volume on the Bacillarieae in his Sylloge Algarum.

This was published in 1891-1894, and contains a list of all diatoms

known at that date. The price is 115 francs.

In this book diatoms are classified into Rhaphidieae, Pseudo-

rhaphidieae, and Crypto-rhaphidieae. This practically agrees with

Van Heurck’s arrangement, and is followed by Schuett and later

writers. The book gives a latin description of the genera and species

with a list of references and illustrations. Five thousand, seven

hundred and forty-one species are numbered and the index, which

includes synonyms, has about double that number of entries.

Several books and monographs have appeared since then, and I

have myself collected references to some 1,450 new species and genera

and varieties since published; so we may reckon about 7,000 species

at the present date.

Various suggestions for new genera have been made during this

period. Cleve in his Naviculoid Diatoms has revived and separated

the old genera Diploneis, Ehr., Pinnularia, and Neidium, and has

added new genera Caloneis, Cymatoneis, Cistula, Pseudo-Amphi-

prora, Stenoneis, and Trachyneis for various forms of Navicula.

Of these Schuett recognizes Cistula and Cymatoneis, but regards the

others as synonyms or subdivisions.

Cleve has also carved out other new genera, Disconeis and Pleu-

roneis out of Cocconeis; Heteroneis, Actinoneis, and Microneis out

of Achanthes; and Gomphoneis out of Gomphonema. He would

also make a new genus Mastoneis for Stauroneis biformis; Scolio-

tropis for Scoliopleura late-striata; and Tropidoneis for certain forms

of Amphiprora and Plagiotropis; in this last instance he is followed by

Schuett. Pantocsek’s Pseudo-Dictyoneis hungarica appears to be a

Dictyoneis.

283

284 FRED B. TAYLOR

Cleve further proposes to divide Pleurosigma by separating under

Gyrosigma those forms in which the striae are at right angles to one

another.

Mereschkowsky has proposed Placoneis and Sellaphora for certain

forms of Navicula, basing his distinction on the form of the endo-

chrome plates; and similarly he has made new genera Stauronella and

Staurophora for Stauroneis constricta and Stauroneis salina respec-

tively.

Other new genera are:—

ANNELLUS, Tempére. A. Californicus, Fossil, Sta. Monica and

Sta. Maria Cal. The valve is folded on itself in the form of a tubular

ring, covered with large separated granules arranged in quincunx.

“‘Diat. du Monde Entier, p. 60.”

AzpeITIA, Paragallo. A. Temperei, Fossil, Spain. Valve tri-

angular, sides almost straight, angles rounded; cellular structure

not reaching the edge of the valve. Cellules hexagonal, in short and

decussate radiating lines, smaller at the centre and border. Margin

hyaline, with a line of fine puncta divided by larger dots. Triceratium

antiquum Pant. I. 13.115 belongs to this genus. D.M.E., p. 326, and

Diatomologia Espafiola, Azpeitia, p. 177, xii.2.

BACTERIOSIRA, Oestrup.

CapsuLa, Brun. Le Diatomiste, II., p. 235; cf. Brun and Tem-

pére, Diat. Japan, 1889, p. 62; Van Heurck, Treatise on Diat., p. 469.

Under the name of Capsula Brun has separated from Triceratium

certain exotic forms having an internal plate with a triangular space

fashioned so as to recall the structure of Entogonia. Triceratium

acceptum, Hardmanianum, radiatum, trilineatum, exornatum,

neglectum, balaniferum, scopus, Normanianum, Trinacria coronata,

princeps, ventricosa, rugosa, and Capsula Barboi and Capsula

biformis, Diat. II, plate xx, are included in this genus.

CATENULA, Mereschkowsky. Fossil, San Pedro, Cal. Outline

of valve plano-convex, girdle view as Eunotia or Fragilaria, frustules

united in bands. Extremities of valve acute, terminal nodules near

the margin.

DIATOMS—NEW GENERA AND SPECIES 285

CENTRONELLA, Voigt. C. Reicheltii, Fresh water, recent,

Holstein. The valve is in the form of a three-legged star, outer

extremities of the limbs capitate, inner slightly bent at the point of

junction, the intermediate portion striate. In girdle view the ends

are not inflated. It belongs to the Centricae. Schmidt’s Atlas, 306,

32-34: Von Schénfeldt, Diat. Germaniae, p. 240, ix., 398; Siiss.

Flora, f. 378.

CLEVEIA, Pantocsek. Diatomiste II, p. 162;, proposed for

Alloioneis Castracanei.

Crievia, Mereschkowsky = Pseudo-Navicula Karsten. Meresch-

kowsky and Karsten unite Van Heurck’s Lyratae and Granulatae

of Navicula in this genus because of the disposition of their endo-

chrome.

CoscinosirA, Gran. Arctic, marine, recent =Coscinodiscus

polychordus Gran. Nansen’s North Polar Expedition, p. 80, il. 33.

Nord Plankton, fasc., xix., p. 20, f. 17. A series of Coscinodiscus

lineatus united by plasmic filaments. Peragallo, Diat. Marines de

France, p. 427 does not consider the form or genus warranted.

Cyctosira, Peragallo. Marine, recent=Thalassiosira subtilis

Ost. A small circular diatom living in globular colonies in a

gelatinous mass, attached to one another by plasmic filaments like

Cyclotella socialis, which inhabits fresh water. Diat. Mar. France,

exx. 10. Peragallo in his note on page 427 admits that this is not a

valid genus.

DETONULA, Schuett. Marine, recent. Sub-genus of Lauderia,

=Lauderia pumila. Valves plane, with a border of spines at the edge

of the disc. It is included in Dactyliosolen by Mann.

DipYMOSPHENIA, Martin Schmidt. A sub-genus of Gom-

phonema, having the rhaphe arcuate, and the valve bent accordingly,

as in Cymbella. Atl. Schmidt, 214. 1-12. D. sibirica, D. curviros-

trum, and D. geminata v. stricta, are the forms included.

DimerosirRA, Peragallo. Marine, recent. Sub-genus of Dimero-

gramma, with convex instead of flat valves, growing as Dimero-

gramma in banded filaments. Diat. Mar. de France, p. 333., Ixxxii.,

13, 14, 15, 19, 20.

286 FRED B. TAYLOR

DossET1A, Azpeitia. Fossil, Spain. Valves unequally convex,

more or less hyaline, with a considerable laminar expansion or frill

irregularly undulate. Also a hyaline frill with irregularly serrate

edge surrounds the less convex valve. Diatomologia Espajola,

P2025 1x 3557:

FRICKEA, Heiden. Brackist, recent=Frustulia Lewisiana,

Batavia, India, Brazil, United States, West Africa; Fossil, Japan.

Atl. Schmidt 264.1.

GOMPHOCYMBELLA, Otto Miiller. Marine, recent, California.

Fossil, Fresh water, Ethiopia; Fresh water, recent, Austria. Valve

as in Cymbella, but with one extremity smaller than the other. Atl.

Schmidt 294. 29-32.

GOMPHOPLEURA, Reichelt=Reicheltia Van Heurck. G. nobilis

Atl. Schmidt 215: 15, 16. Valve with one extremity smaller than

the other, but cuneate also in girdle view. Fossil, Japan, Hungary,

Bohemia.

Gonioceros, Peragallo. G. armatum=Chaetoceros armatum,

West. Diat. Mar. France, p. 471, cxxxv. 6. Frustule quadrangular

with the corners cut off, whence proceed long curved spines with

blunt ends; there is also a smaller spine at each end of the straight

sides.

HANDMANNIANA, Peragallo. H. Austriaca. Mitt. Mik. Vereins

Linz, 1913, I, p. 36, taf. und fig. Bot. Cent., exxv, 1914, p: 622)

no figure. Cocconeis in form with border: ‘‘die mitte von einen

stark aufgetriebenen buckel (15-17 streifen) durchzogen; auch der

rand zeigt feine linie mit perlen. Die unterschale zeigt mittel strei-

fungen, welche von der schwach sichtbarn rhaphe aus alternieren.”’

I have been unable to find the Proceedings of the Linz Micro-

scopical Society, which contains the figure of this species, and am

unable to reconstruct it mentally from the description. Fresh water,

recent. Alm See, Austria.

HERIBAUDIA, Peragallo. Fossil, Auvergne. H. ternata, Diat.

d’Auvergne, p. 196, v. 25. Van Heurck, Treatise on Diat., p. 542,

fig. 291. Valve circular, disciform, hyaline or finely punctate, bearing

DIATOMS—NEW GENERA AND SPECIES 287

on its edge three small expansions or conical wings, between which

extend three larger wings, rounded or plicate.

LicMOSPHENIA, Mereschkowsky. Marine, recent, Adriatic

Villefranche, Sumatra. Frustules as in Licmophora, but with two

openings in the septa instead of one opening. The superior opening

is small, the inferior is larger.

OESsTRUPIA, Heiden. Marine, recent=Navicula (Caloneis)

Powellii with its varieties and Navicula quadriseriata Atl. Schmidt.,

264. 4, 5, 8, 9. Adriatic, United States, Egypt, and Balearic Islands.

PERAGALLIA or PERAGALLOA, Schuett. Marine, recent, Baltic.

It has the body of a Dactyliosolen with the horns of a Chaetoceros.

P. tropica. The horns at the two extremities are turned in the

same direction. Schuett, Bacillariales, p. 86, fig. 142: Van Heurck’s

Treatise on Diat., p. 419, fig. 137; Diat. Mar. France, p. 475, cxxvi., 9.

Perit1A, Peragallo. Marine, recent. Nas:au, Bahamas. Valve

bacillar, arcuate, covered with transverse striae interrupted by two

longitudinal lines. Diat. du Monde Entier, p. 146.

PHAEODACTYLON, Bohlin. Fresh water, Finland. P. tri-

cornutum. Valve a three pointed star, the arms in one plane; the

outer half of the arms generally hyaline. Von Schonfeldt’s Siiss-

wasser Flora Deutschlands, etc., p. 173, fig. 379. Something like

the Manx arms cut off at the knees.

PLANKTONIELLA, Schuett. Marine, recent=Coscinodiscus sol.

The valve is surrounded by a broad membranous frill; in girdle view

itis: Jinear,, “Trans. Mic. Soe. 1860; p. 38, 1,452: Atl. Schmidt

58, 41, 42, 45: Van Heurck Syn. 129. 6: V. H. Treatise, p. 534, fig.

279: Diat. Tar. France, p. 426, cxvi. 5. Bay of Bengal, Indian Ocean,

Fossil, Barbadoes.

PSEUDO-AMPHIPRORA, Cleve, Syn. Naviculoid Diat. I., p. 70

= Navicula lepidoptera,= Nav. arctica Cl. Van Heurck includes it

in Orthotropis, Peragallo considers the genus good, as the structure of

the frustule and the endochrome are typical. Greg. Diat. Clyde,

p. 34, iv. 60.

288 FRED B. TAYLOR

PSEUDO-NITZSCHIA, Peragallo. For forms between Nitzschia

and Synedra, includes N. (?) seriata, Rhaphoneis cuneata, and Syne-

dra sicula. The power of movement indicates the presence of a rhaphe

or of longitudinal openings on the keel. Diat. Mar. France, p. 298,

Ixxii, 25-29., Italy, Scotland, Arctic.

PSEUDO-PHXILLA, Forti. Nuova Notarisia, XX., 1909, pp. 25,

29: plate ii. Fossil, Italy; Richmond, Va., etc. Valves unequal,

cylindrical, with or without spines at the end of the longer valve,

smaller valve more or less convex, often included in the longer valve.

PSEUDO-STICTODISCUS, Grunow=Stictodiscus Eulensteinii Castr.

Challenger Diat., i. 7. Van Heurck and Schuett include in Tricera-

tium; it resembles Stictodiscus, but wants the radiating folds or plicae.

RuopatoprA, O. Miiller.=Epithemia partim. Frustules cunei-

form or sub-globular, valves keeled, without lines of junction,

thaphe and central nodule distinct, terminal nodules indistinct.

Zone striate or plicate. Transverse section of valve is like a wide

V with unequal arms, making the section of the frustule trapezoidal;

the rhaphe occupying the acute angle is seldom visible, as the valve

falls flat.. ‘Jl. R. Mic: Soc. 1900, p: 228: Atlas Schmidt, plates

253-256, 265, 294: Diat. Mar. France, lxxvii. Rhopalodia includes

Epithemia gibba and certain forms from Nyassaland.

SCHMIDTIELLA, Ostenfeldt. S. pelagica. Frustules in chains,

valve broadly elliptical, surface undulate, minute processes at

extremities, hyaline: akin to Grayia. Kohchang Flora, 1902, p. 24,

fig. 20.

SCHROEDERELLA, Peragallo. Marine, recent.=Lauderia delica-

tula Schroeder=Detonula delicatula Gran=Lauderia Schroederi

Bergon=Detonula Schroederi Gran. Not=Lauderia delicatula

Peragallo. Nuova Notarisia April, 1914, p. 131, Naples, Arcachon.

SECALLIA, Azpeitia. Diat. Esp., pp. 217, 176., vi. 6, 7. Moron.

S. Caballeroi. Valve elongato-rhomboidal with rounded angles, and

with a deep depression across the shorter diameter. Granules

scattered over the valve without fixed direction, but disposed in

transverse lines on connecting zone, no rhaphe or nodules.

DIATOMS—NEW GENERA AND SPECIES 289

SEMSEYIA, Pantocsek. Fossil, Kertsch and Hungary. Valve

arcuate, capitate, with transverse striae, marginal or complete;

resembles in shape Eunotia gracilis. Frustule in zonal view with

transerse striae interrupted by a longitudinal hyaline line inflated.

at the extremities. Klebschiefer von Kertsch von Dr. Jos. Pantocsek.

Verhand. der Russ. Kais. Mineral Gesell. Serie 2, Band 39. 1901, 2.,

p. 644, taf. xii. 30, 31.

SMITHIELLA, Peragallo. S. marina=Himantidium marinum

W.S. Ann. Mag. Nat. Hist. 1857, ii. 14.=Eunotogramma debile

Grun. Van Heurck Syn. 126, 18, 19; Diat. Mar. France, p. 343.

Ixxxii. 36. A cymbiform Odontidium. Marine, recent, Biarritz.

STREPTOTHECA, Shrubsole. Leisure Hour, Nov. 1890, p. 34.

J. Quekett Mic. Club, 1890, p. 259., xiii. 4-6. Peragallo, Diat. Mar.

France, p. 458, cxxi., 10. Estuary of the Thames. Peragallo places

it with Rhizosolenia, Schuett considers it “incertae sedis,’’ Ostenfeldt

and Van Heurck place it with Eucampia. According to Cleve S.

Tamesis=S. maxima from the Indian Ocean and Malay Archipelago.

It is also found in the Red Sea and North Atlantic.

SYNEDROSPHENIA, Paragallo. Diat. Mar. France, p. 312, a

subgenus of Synedra, to include Sceptroneis cuneata, Synedra clavata,

andSynedradubia. Bahamas, Cayenne, Barbadoes, Samoa, Banyuls.

Valve cuneate, Marine, recent and Fossil.

SZECHENYIA, Pantocsek. Hungary. Diat. Szliacs, pub. Fried-

lander, p. 16, ii, 58-61. Valves cylindrical, domed, hyaline; with

longitudinal septa and hyaline rays; zone with transverse lines.

Grows in a chain. It is like Cladogramma in girdle view, and is

placed among the Melosireae.

TEMPEREA, Peragallo. T. Mephistopheles. Marine, recent.

Tamatave, Madagascar. Diat. du Monde Entier, Nos. 98-100.

Valve circular, convex, with border of radiate oval granules. Cf.

Skeletonema mediterraneum Grun.

TEMPERELLA, Forti. T. miocenica. Fossil, Bergonzano, Italy.

=Aulacodiscus miocenicus Forti, Nuova Notarisia, Jan. 1909,

p. 39: April 1914, p. 109 note, vi. 1, 3, 4,5. Valve circular, divided

290 FRED B. TAYLOR

into 18 or more sectors each with rows of puncta parallel to the middle

row. There is a minute process near the outer margin of the valve in

each alternate sector. Puncta minute, arranged in quincunx.

VALDIVIELLA, Schimper.

VANHEURCKIELLA, Pantocsek. Diat. Foss. Hung. III, 1, 4.

Van Heurck Treatise on Diat., p. 540, fig. 288. Fossil, Oamaru.

V. Admirabilis Grun. Van Heurck considers it a spongiolithum.

WEISSFLOGIA, Janisch. Gazelle Exped. i., 12-17. W. Mac-

donaldii, King George’s Sound, Australia, resembles a twisted

Surirella with short transverse markings across the spaces between

the costae.

It will be noticed that many of these genera are formed for single

species already described, or are very limited in extent. I have

failed to find any description of Valdiviella or Bacterjosira, and

doubtless this list is in other respects incomplete, but it represents a

csiderable amount of work in literature not easily accessible.

55 Grand Avenue, Bournemouth, England.

DEPARTMENT OF NOTES AND REVIEWS

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 mem-

bers are invited to submit such items. In addition to 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.]

THE NEW SECRETARY AND EDITOR

Owing to the pressure of other duties the undersigned has been

compelled to retire as Secretary of the American Microscopical

Society and Editor of the Transactions, at the end of the current year

and volume. This concludes ten years of service which is probably

as much as one member should be called upon to render, and doubt-

less as much as the Society can afford to endure.

The Executive Committee has voted to appoint, subject to con-

firmation at the coming business meeting of the Society in St. Louis

in affiliation with the American Association for the Advancement of

Science, Professor Paul S. Welch of the University of Michigan,

Ann Arbor, Michigan, as Secretary-Editor for the next term of

three years. Indeed, Dr. Welch has kindly undertaken to begin

his work with the October number of Volume 38. All correspon-

dence relative to membership, Jvansactions, and exchanges should

therefore be addressed to him.

The former Secretary had hoped to present a statement to the

Society of the work of the decade, but this does not seem possible

at the present time. He must content himself with making a final

request of the membership to give the new Secretary the utmost

support in his effort to make the Transactions still more effective in

stimulating research and in publishing its results.

T. W. GALLOWAY

291

292 NOTES AND REVIEWS

ENTOMOLOGICAL ABSTRACTS

Sex Determination in Trialeurodes—Stoll and Shull (1919,

Genetics, 4:251-260) have investigated the previously reported state-

ment that in 7rialeurodes (Aleurodes) vaporariorum the partheno-

genetic eggs produce females in the English representatives of the

species and males in those occurring in the United States, and that

fertilized eggs produce both sexes in equal numbers. A series of

carefully planned breeding experiments with American stock in-

dicated that the unfertilized eggs do produce males, but there was no

evidence for the belief that the fertilized ones result in both males

and females in equal numbers. Instead, the evidence supports the

conclusion that all fertilized eggs produce females, thus corresponding

with the case of the honey bee.

Pentatomoidea.—Hart (1919, Bull. Nat. Hist. Surv., Illinois,

13:157-223) has summarized the Pentatomoidea of Illinois and con-

structed keys to the Nearctic genera, thus presenting a very useful

and important work on this group of Hemiptera. This paper is

exclusively systematic in nature and has much to commend itself

to workers in entomology.

Canadian Bark-beetles—Swaine (1918, Dep’t Agr., Dominion of

Canada, Entomological Branch, Bull. 14) has published a treatise on

“Canadian Bark-beetles’”’ which makes readily available much impor-

tant data on Canadian Scolytidae. An extensive account is given of

the structure and general biological features of these insects, followed

by descriptions of the various species concerned accompanied by

keys for the identification of the same. Thirty-one plates and four

text figures add much to the value of the paper. Owing to the nature

of the paper it is not readily summarizable but it is a work worthy

of commendation and is indispensable to students of Coleoptera.

Drosophila and Disease-—Sturtevant (1918, Journ. Parasitology,

5:84-85) reviews the circumstantial evidence that flies of the genus

Drosophila may be carriers of disease. In the tropics D. repleta and

D. caribbea have habits which place them under strong suspicion,

but contrary to the meager literature on this subject, there seems to

be little reason for regarding D. melanogaster (ampelophila) as par-

ticularly dangerous.

Nematode Parasite of Sciara —Hungerford (1919, Journ. Para-

sitology, 5:186-192) reports certain biological features of a nematode,

AMERICAN MICROSCOPICAL SOCIETY 293

Tetradonema plicans, which parasitizes the mycetophilid fly, Sciara

coprophila, in the larval, pupal, and adult stages. From two or

twenty nematodes representing both sexes were found in a single

host. A striking sexual dimorphism is manifested, the females

reaching a length of 5 mm. while the males are less than 1 mm. long.

Likewise the sexually mature female is characteristically swollen

about midway between the anterior and posterior end, due to accumu-

lation of great numbers of eggs “‘beneath the cuticula, which serves

as a retaining capsule.’’ It seems probable that the parasite gains

entrance into the host by the latter swallowing the eggs of the

nematode, the eggs hatching and the young parasites boring through

the walis of the alimentary canal into the body cavity of the larva.

There is no evidence of an alternate host in the life cycle. In connec-

tion with the copulation activities as many as four males may become

attached to one female and so remain until the female completes her

egg capsule and dies. A maximum of 5,520 eggs per female is

recorded.

Propleura of Orthoptera.—Du Porte (1919, Can. Ent., 51:147-153)

has made morphological studies of representatives of the principal

orthopteran families in investigating the problem of the presence or

absence of the propleura and the significance of the pronotal sulci.

Evidence secured indicates that the propleurum has not been eli-

minated by the downgrowth of the pronotum but persists on the

inner side of the latter which has descended over it. The typical

pleural] sclerites are present and possess a musculature similar to the

homologous sclerites on the mesopleurum and metapleurum. The

sulci are mere folds resulting from mechanical stresses and do not

mark off areas homologous to the prescutum, scutum, scutellum and

postscutellum in the other thoracic segments. It is therefore claimed

that these terms should not be applied to the pronotal areas.

Grylloblatia campodeiformis.—Walker (1919, Can. Ent., 51:131-

139) reports on seven additional specimens of the remarkable orthop-

teroid insect, Grylloblatia campodeiformis, one of which is a mature

male and four are nymphs representing both sexes. Males and

nymphs are described for the first time and important morphological

data are presented. The genitalia have been given critical examina-

tion since the phylogeny of this insect is of particular interest. The

opinion is expressed that the ‘‘Panisoptera’’ (which includes the

294 NOTES AND REVIEWS

Blattoidea, Mantoidea, and Isoptera) and the Orthoptera represent

two branches from the same stem and that Grylloblatta is the sole

survivor of a branch ‘‘which separated from this stem before the two

main branches had become differentiated.”

Staining Coccidae.—Gage (1919, Ent. News, 30:142-144) has

found a method for permanently staining the exoskeleton of scale

insects. After trials with several stains, it was found that sduer-

fuchsin gave best results but had the serious disadvantage of fading

after a time, due to the alkali remaining in the tissues from the KOH

cleaning fluid. This difficulty was eliminated by introducing hydro-

chloric acid to form an excess and mounting in acid balsam. The

following formula represents the most satisfactory proportions of the

ingredients:

Siuerfuehsin’ yi acm aces acento ce 0.5 gram

10 per cent hydrochloric acid.......... 25,.0: cc.

Mistilled waterrercce eee sce wees 300.0 ce.

Remove specimens to be stained from the KOH and wash thoroughly

in three or four changes of distilled water; place in Syracuse watch-

glass containing a few cubic centimeters of the staining fluid and leave

for from 20 to 40 minutes; remove and use subsequent treatment

ordinarily employed in preparing scale insects. Care should be used

that the specimens remain in such liquids as carbol-xylene, clove oil,

or alcohol long enough to insure the complete clearing or dehydration.

Olfactory Sense in Larvae——McIndoo (1919, Ann. Ent. Soc. Am.,

12:65-84) presents morphological and experimental data on the

presence of an olfactory sense in the larvae of Lepidoptera. The

larvae of five species, four moths and one butterfly, were tested with

a variety of substances giving odors and, in general, found to respond

to such chemical stimuli although differences in the average reaction

times seemed to depend upon the degree of sluggishness of the animal

rather than specific sensitiveness to the odors. Pores, widely distri-

buted on the head and its appendages, legs, dorsal surfaces of pro-

thorax and last abdominal segment, and on the anal prolegs are struc-

turally well adapted to receive chemical stimuli and may constitute

the morphological basis for the olfactory response of the animal

although experiments were not performed to determine their exact

function.

Department of Zoology, Pau S. WELCH.

University of Michigan.

AMERICAN MICROSCOPICAL SOCIETY 295

I. FORCED MOVEMENTS, TROPISMS, AND ANIMAL CONDUCT

Dr. Loeb is chairman of the board of editors which is issuing a

series of monographs on experimental biology and general physiology.

These monographs which collectively cover a wide field are designed

to encourage quantitative experimental work as against descriptive

and speculative; and to this end each one presents a summary of the

exact work that has already been done in its particular field.

Dr. Loeb introduces the series with a volume treating forced

movements and tropisms in relation to animal conduct. His analysis

is designed to illustrate the application of the quantitative method to

the study of animal behavior. He holds that such study supports

his own well-known theory of tropisms or forced movements. This

hypothesis, first propounded by him some thirty years ago, is in

antithesis to the more anthropomorphic idea that animal behavior is

the result of trial and error, of pleasure and pain, of curiosity or other

internal physiological states.

In Chapter II the author, in a most suggestive and lucid way,

shows how the fundamental symmetry of animals is the starting

point and foundation for an exact analysis of behavior. The impor-

tance of animal symmetry lies in the fact that the morphological

plane of symmetry is also the dynamical plane of symmetry. This

morphological symmetry is the gross expression of equivalency of

chemical constitution and of reacting stuffs, and this gives a basis

for quantitative and comparative experiments involving the similar

elements both of reception and response.

To illustrate by a quotation: ‘‘When symmetrical elements of

the eyes are struck by light of the same wave length and intensity,

the velocity of photochemical reactions will be the same in both

eyes. Symmetrical spots of the retina are connected with symmetri-

cal elements in the brain and these in turn with symmetrical muscles

As a consequence of the equal photochemical reactions in the sym-

metrical spots of the retina, equal changes are produced in the

symmetrical brain cells with which they are connected, and equal

changes in tension will be produced in the symmetrical muscles on

both sides of the body with which the active brain elements are

connected. On account of the symmetrical character of all the

changes no deviation from the original direction of motion will

296 NOTES AND REVIEWS

occur. If, however, one eye is illuminated more than the other eye,

the influence upon the tension of symmetrical muscles will no longer

be the same and the animal will be forced to deviate from the original

direction of motion.’”’ The bilaterally symmetrical organism serves

as a kind of pair of physiological scales or balances, by which one

may appraise the forces causing movement. Couple this with the

asymmetrical polarity of head end and tail end (or free end and

base) and one can anticipate the general method of the book. But

no one can anticipate the brilliant and vivid illustrative experiments

and the special interpretations of these in the support of the general

hypothesis.

In Chapter three on ‘‘Forced Movements,” the author illustrates

three kinds of forced movements: circus motions (involving some

destruction of symmetry of tension), the tendency to go backward,

and the tendency to move forward. These latter movements are

related to the antero-posterior polarity.

In the remaining chapters the author gives experiments and

their interpretation under the following heads: Galvanotropism,

Heliotropism, Geotropism, Rheotropism, Anemotropism, Stereo-

tropism, Chemotropism, and Thermotropism. Except in the case

of the first of these a large part of the account is of new experiments.

A relatively large part of the book is given to the discussion of

heliotropism. There are special chapters dealing with particular

problems involved in heliotropism, as: light of different intensity

from double sources; the Bunsen-Roscoe law for heliotropic reactions;

effect of rapid changes in intensity of light; relative effectiveness of

different wave lengths; charges or reversals of heliotropism.

The concluding chapters XVIII and XIX deal with instinct and

memory images in relation to the theory of forced movements.

This the author rightly states is the real test of the theory. While

suggestive, these are the least convincing and satisfactory chapters

of the book.

Instincts are tropistic reactions modified by hormones,—or

otherwise. A quoted example will give the author’s method. “The

fact that eggs are laid by insects on material which serves as a nutrient

medium for the offspring is a typical instinct. An experimental

analysis shows that the underlying mechanism of the instinct is a

positive chemotropism of the mother insect for the type of substance

AMERICAN MICROSCOPICAL SOCIETY 297

serving her as food; and when the intensity of these volatile sub-

stances is very high, i.e. when the insect is on the material, the egg-

laying mechanism of the fly is automatically set in motion. Thus

the common house-fly will deposit its eggs on decaying meat but

not on fat; but it will deposit it on objects smeared over with assa-

foetida, on which the larvae cannot live. It seems that the female

insect lays her eggs on material for which she is positively chemotro-

pic, and this is generally material which she also eats. The fact

that such material serves as food for the coming generation is an

accident. Considered in this way, the mystic aspect of the care of

insects for the future generation is replaced by the simple mechanistic

conception of a tropistic reaction.”

The author’s treatment of memory images and the general pheno-

mena of association seem to indicate a negative psychiotropism on

his part which results in “‘forced”’ conclusions.

It is not often, in spite of his mechanistic determinism, that the

author’s logic actually nods. But surely the fact that ‘Passenger

pigeons when reared by ring doves refuse to mate with their own

species but mate with the species of their foster parents’? does not

“show incidentally that racial antagonism is not inherited but ac-

quired.””’ The most that it can “show” is that if inherited in any

degree such aversion can be lost thru experience.

The book is wonderfully suggestive and is a strong exposition of

the purely mechanist thesis.

Monographs on Experimental Biology: Volume I, Forced Movements, Tropisms, and Anima

Conduct, by Jacques Loeb. 210 pages, illustrated. J. B. Lippincott and Company, Philadelphia. 1918.

Price $2.50. mam A. 7

tA yr \ ‘ R feenyreirn LAAs

Il. THE ELEMENTARY NERVOUS SYSTEM

This is the second in the series of volumes summarizing the

results in various special fields of experimental physiology. It is

written with the directness and clearness characteristic of Professor

Parker’s writings.

“Elementary” in this title is used in a strict sense, as the author

confines his discussion to the conditions found in the three simpler

phyla of multicellular animals,—the sponges, coelenterates, and

ctenophores.

298 NOTES AND REVIEWS

In an introductory chapter the author calls our attention to the

fact that we take an anthropomorphic view of the behavior and

capacities of the lower animals because our first studies of nervous

structure and phenomena were done upon man and the higher ani-

mals. In this connection he emphasizes that the unitary neuro-

muscular mechanism of the higher animals, consisting as it does of a

group of receptors connected with a well-organized adjustor or

internuncial group of neurones which in turn control a specialized

effector apparatus, is found only in the differentiated animals.

While elementary in relation to the whole complex system, this reflex

arc is not elementary in a primitive sense.

For the most part in the groups studied the neuro-muscular

system consists of many peripheral sensory cells, often with well

specialized receptive portions, with deep branching ends which

connect more or less directly with the muscular elements without any

complex adjusting or central organ. This latter may be fairly looked

upon as a later, indeed the latest, and higher step in the evolution

of the apparatus. And yet, as we might well expect, conditions are

found which suggest gradations toward this higher type.

This direct connection of receptors and effectors is itself not the

primitive condition. The author conceives that the antecedent of

this apparatus is a still simpler condition in which is only the effector

or muscular element. With this foundation of independent effectors,

themselves directly but slowly sensitive and responsive to the essen-

tial tensions and stresses, the gradual differentiation of the other

parts as accessory to them is entirely plausible.

Dr. Parker organizes his presentation of the subject on this

interpretation of his findings by discussing in Section I the ‘‘Effector

Systems,” as in the sponges and in certain independent effector

systems of higher animals; in Section II, the ‘‘Receptor-Effector

Systems”’ as illustrated in the Sea-anemones, Jelly fishes and Hy-

droids; and in Section III, with certain anticipations in later chapters

of Section II, he outlines a scheme correlating these more primitive

conditions with one another and with those animals in which the

adjustors or central organs also appear.

By a series of experiments upon suitable sponges it was found

that the common flesh is contractile, the oscula open and close, the

incurrent pores may close either by the modified ameboid motion

AMERICAN MICROSCOPICAL SOCIETY 299

of the pre-membrane or by the contraction of a sphincter-like band

of cells in the wall of the canal itself. These operations may be

studied directly or by the modification of the currents of water main-

tained thru the sponge by the flagellate cells in the specialized canals

of the sponge. Various, tho somewhat limited stimuli may operate

in producing response in these effectors,—as presence or absence of

sea water, existence of currents in the water, injuries, and changes

in the chemical condition of the water. Critical experiments, de-

tailed at length, warrant the conclusion that the stimuli operate

directly upon the simple independent contractile elements, and not

thru specialized receptors.

In Chapter IV it is shown that such independent muscular

effectors are not confined to sponges but are present also in certain

organs of higher animals. The sphincter of the pupil of the eye,

the amnion of the chick, the embryonic heart of vertebrates (and

probably in some degree the adult heart) show this immediate respon-

siveness of muscle without the intervention of special sensory ele-

ments. These condition; may also be accompanied by ordinary

nervous control of the muscles.

The transmission of impulses from one part of the sponge to

another takes place by a sluggish neuroid rather than a nervous

process. This is protoplasmic and primordial, and apparently back

of the more specialized nervous transmission. This too is a condition

retained in certain effectors in the higher animals. Evidences of

such neuroid transmission in the absence of actual nervous structures

are seen in the coérdinations of ciliary action in many higher animals

including vertebrates, and in the swimming plates of Ctenophores.

Section II with eight chapters deals with the more prompt and

effective receptor-effector system as illustrated in the Coelenterates.

There is added here a more specialized sensory surface fitted to receive

more exactly the various stimuli and to transmit their influence thus

indirectly to the responding apparatus. In the sea-anemones there

are four types of effectors:—the mucous glands, the cilia, the nettle

cells, and the rather numerous special sets (13 in Metridium) of muscle

fibres. Among these only the muscles give any experimental evidence

of nervous control. The others are independent effectors.

Various observations show that there is wide spread transmissive

connection of a nervous kind between the epithelium and the deep

300 NOTES AND REVIEWS

muscular layer which makes it possible to bring the whole muscular

effector apparatus into response by a surface stimulus at any point

of the body. The author holds that this nerve net is not in the sup-

posedly nervous layers of ectoderm and entoderm, but rather in the

supporting lamella between them.

In Jelly fishes there is both an increased specialization of the recep-

tor system (e.g., the marginal sensory bodies) and of the muscular

effectors, as well as of the nerve net which connects them. There is

in them a corresponding promptness of response, with a remarkable

codrdination of the total bodily reaction thru a very definite wave of

contraction evidently made possible by the nerve net.

In Chapters IX and X the author traces the contrasts and corre-

spondences bet ween this nerve net as the main connecting apparatus in

Coelenterates and its existence in special organs in the higher forms—

as in the heart and intestine of vertebrates (often side by side with

the neurone synaptic system). This nerve net is particularly suitable

to autonomous structures and organs and to situations in which the

transmission needs to be diffuse and general rather than to produce

specific and local reflexes. Yet in even such highly autonomous

organs as tentacles in the Coelenterates show themselves to be, there

is some degree of physiological polarity present, in that transmission

occurs more freely in one direction than in others; and they may fairly

be said to show evidences locally of the beginnings of nervous organi-

zation of a grade higher than the diffuse nerve net.

Functionally the transition to the condition which we know as

reflexes, in which a local and particularized muscular response follows

regularly from equally local and specific stimulus might well come in

this gradual way thru increased polarization of originally diffuse

apparatus. A localized esophageal response in Metridium by a

specific stimulation of the tentacles by fish meat has al] the ear-

marks of such a reflex—superimposed upon the more diffused net

reactions.

Chapters XI and XII analyze some of the more complex effective

operations of Actinians (in which field the author and his students

have done leading and conclusive work) to determine whether these

indicate any evidences of the higher internal codrdinative and unify-

ing functions which characterize those animals having a central

apparatus. Among the most promising of these are the operations

AMERICAN MICROSCOPICAL SOCIETY 301

of feeding, rhythmic or other contractions and expansions, the creep-

ing activity of the pedal disc, and the general modifiability of behavior

thru the experiences of the animals. No such associative results are

revealed as would imply a nervous integration higher than the net

would supply. The best that can be said seems to be that there is a

smal] group of feeding activities which localize as reflexes.

Chapter XIII is devoted to Hydroids, particularly illustrated by

Corymor pha, in an effort to discover whether these animals, regarded

as more primitive than the Actinians, have a receptor-effector

apparatus more simple than they, and thus furnish a clue to the

possible evolution of the higher coelenterate condition from that in

the sponges. In these forms the muscular effector system reduces

essentially to an ectodermal longitudinal system and a circular

entodermic one. These are further differentiated into the stalk

muscles, those of the hypostomial (‘‘proboscis’’) extension of the

stalk, and those of the two groups of tentacles. Of these muscles the

circular entodermic ones seem to be directly stimulated (i.e., without

nervous intermediation) and therefore are more like the slow acting,

primitive type found in sponges. They operate in connection with

the vacuolated cells to bring the hydroid back to it elongated form.

The ectodermic muscles on the other hand are relatively prompt in

action and are controlled by a nervous system of ectodermic receptors

and a nerve net—as in actinians. Corymorpha also shows specialized

reflexes analogous to those in Metridium. The author holds that

Corymorpha evidences behavior and nervous organization of reduced

actinian type rather than intermediate between the sponges and the

actinians.

Section III, which comprises one final chapter of ‘‘Conclusions’’

is devoted to giving an outline of the differentiating steps in passing

from the elementary independent effecton to the complex central

nervous system of the higher animals. The whole chapter is a concise,

condensed outline, and no brief abstract of it can do justice to its lucid

presentation. It can serve only as a Table of Contents to the chapter.

1. The starting point in the evolution of the nervous system in

metazoa is the simple independent effector of smooth muscle cells.

Such an apparatus is functionally limited to the reception of the

grosser, more physical types of stimulus, is slow and sluggish in its

responses, and the diffuse transmission is of a protoplasmic neuroid

302 NOTES AND REVIEWS

rather than specialized nervous type. This condition is realized in

sponges.

2. Around this starting point of response the receptor system

next develops, making for promptness and elaboration of reception

of stimuli. In this way comes distinctions in the categories of possible

stimulation, and extension of its range to milder and more refined

types of stimulus. Hypothetically, there are several possible steps

in the elaboration of such a receptor-effector system. The first of

these would be the immediate connection of nearby epithelial cells

with the Effectors. This simple condition is as yet hypothetical. The

simplest form actually found is where the inner branching ends of the

receptors connect not alone with the muscles but with one another in

a more or less complex network. This is illustrated in the tentacles of

Actinians. Functionally this increases the dispersal of the effective

results of stimulation in a diffuse way to many muscles, and gives a

nervous instead of a neuroid character to transmission. A further

complication of this is seen where special branched cells are connected

with this nerve net. These have been called “ganglia.” The author

thinks that the term ‘‘protoneurone”’ may rightly express their nature.

This is illustrated in the Coelenterates at many points. There are

experimental evidences that a still further specialization of this nerve

net is in limiting or specializing the routes and directions of trans-

mission. Functionally the result in such as we usually describe under

the term reflexes. It involves a localized response as characteristic

of a localized stimulus. This involves some sort of polarity in the

nerve net. This is found in certain actinian reactions. All of this

is without any organization or any responses which simulate the

central nervous stations of the higher animals.

3. Broadly anticipating the transitions to anatomical and func-

tional conditions in the perfected receptor-adjustor-effector scheme

the author suggests the main changes to be: the inward migration

and concentration of the primary receptors and of the diffuse net

elements into sheets, bands, and masses; more elaborate and perfect

polarization and the increase of the special reflexes; the appropriation

in many cases of secondary sensory cells by which the receiving func-

tion is again differentiated; and perhaps most significant of all the

introduction of the neurone-synaptic apparatus whereby the route of

the passage of impulses is more definitely determined. This carries

AMERICAN MICROSCOPICAL SOCIETY 303

the polarization phenomenon a step further. There follows too in

higher forms, apparently, the mechanism of the control of synaptic

or other resistances by which inhibition or augmentation of impulses

takes places.

The book will aid the general teacher and student of biology at a

most interesting point.

Monographs on Experimental Biology, Volume II: The Elementary Nervous System, by G. H.

Parker. 229 pages, illustrated. J. B. Lippincott, Philadelphia, Price $2.50.

Nerrology

DR. WILLIAM GILSON FARLOW

Died at his home in Quincy Street, Cambridge, on the third day of

June, after an illness of three weeks. He was born in Boston, Decem-

ber 17th, 1844, and graduated from Harvard College in the Class of

1866, obtaining the degree of A.M. in 1869 and of M.D. in 1870.

After receiving the medical degree he studied Botany in Europe for

several years, for the most part at Strassburg in the laboratories of the

distinguished botanist, Professor A. de Bary. After his return to

America he was for a time assistant to Professor Asa Gray, and was

also connected with the Bussey Institution. In 1874 he was appoint-

ed Assistant Professor of Botany in Harvard, receiving in 1879

the title of Professor of Cryptogamic Botany which he held for a

period of forty years. On June 10th, 1900 he was married to Miss

Lilian Horsford, daughter of Eben N. Horsford.

The honorary degree of LL.D. was conferred on him by Harvard

in 1896, by the University of Glasgow in 1901, and by the University

of Wisconsin in 1904. In 1907 he also received the degree of Ph.D.

from the University of Upsala. He was a member of the National

Academy of Sciences, the American Philosophical Society, the

American Academy of Arts and Sciences, the Philadelphia Academy

of Natural Science, the American Association for the Advancement

of Science, of which he was President in 1906, the Linnaean Society of

London, the Paris Academy of Science as well as of numerous other

scientific bodies in this country and abroad.

In America, Professor Farlow was a pioneer in Cryptogamic

Botany, and for many years has been justly regarded as preéminent

in his profession, both in this country and abroad. Through his

published writings, the inspiration of his teaching, his high ideals,

versatility and extraordinarily wide learning he has long occupied

a unique position among his scientific friends and associates, and has

exercised an influence on the study and development of this chosen

field the importance of which can hardly be overestimated.

304

LIST OF MEMBERS

HONORARY MEMBERS

Crisp, FRANK, LL.B., B.A., F.R.M.S.,

5 Landsdowne Road, Notting Hill, London, England

IPBEAUME WUAGNUS sf c\ie:cereis aro's elec walsveteyelere 3833 Lancaster Ave., Philadelphia, Pa.

LIFE MEMBERS

Brown, J. STANFORD, Ph.B., A.M.,........P.O. Box 38, Far View, Black Hall, Conn.

(CAPES OE DTH BUNKER ja cree cio cise is cis eseysie re ekerele ei P.O. Box 2054, Philadelphia, Pa.

DuNCANSON, Pror. Henry B., A.M............ R.F.D. 3, Box 212, Seattle, Wash.

IP REIOU MER OF fA THURS Elec sie.cls serie oiseve seals sleie 52 E. 41st. St., New York City

EVA EEN MOHING Croom cy erm cai eine candies te cee Chicago Beach Hotel, Chicago, Ill.

MEMBERS

The figures denote the year of the member’s election, except ’78, which marks an

original member. The TRANSACTIONS are not sent to members in arrears, and two

years arrearage forfeits membership. (See Article IV of By-Laws)

MEMBERS ADMITTED SINCE THE LAST PUBLISHED LIST

BREWSTER, W. B. MOontTGOMERY, CHARLES S.

Brown, ALIce L. Prarr, Hi. S.

DEMETER, THEODORE E. Prosst, Rev. LEOPOLD

Farmer, Ernie I. PRoctTER, WILLIAM

GILBERT, E. M. ScHEAR, E. W. E.

Grarr, JOHN H. SHEERAR, LEONARD F.

Hopkins, FRANK B. Tucker, O. C.

KLINEDINST, HERMAN Wismer, NETTIE M.

Lowrey, ELEANOR C.

ACKERT, JAMES EpwarbD, Ph. D., ’11........ Kas. State Ag. Col., Manhattan, Kas.

ALLEN, HARRISON SANBORN, M.A.,715...... 442 Farmington Ave., Waterbury, Conn.

ASIEN, We RAV MAG TIS. ooo 212 So. Washington St., Bloomington, Ind.

AECEN: WVNERED EAM O48 oe 2 ne tere Scripps Inst., La Jolla, Cal.

ANDERSON MMACN 1102 ocentaciics oeicrsisien Vane ieee Station A, Lincoln, Nebr.

ANDRAS ape) Cre Be Ace VED ean iyo) lance cyte inte cee 540 S. Main St., Manchester, Ill.

PMI OND RANT OUD occ le os Ss od aoe eameets 408 House Building, Pittsburg, Pa,

PRERIERER SVU AES De LG 2510 5.5 aches a 0, of! a.'tie.0 Sus em 21 Park Rd., Wyomissing, Pa_

ATHERTON, Pror. L. G., A.B., M.S., ’12........ State Normal School, Madison, S.D_

PNT WN CHOEP RENNES 6 17195 oish ao: 0d e's bicle aie Siero gna een 16 Seneca Parkway, Rochester, N.Y

306 LIST OF MEMBERS

BALDWIN: IERBERT BS, CASY sence site lhe aoe ae 927 Broad Street, Newark, N.J.

BARKER, FRANKLIN D., Ph.D. ’03........... University of Nebraska, Lincoln, Neb.

BARRE, WES) We, is Ct eA OED 2 oo Re sce any ale Rae a Clemson College, S.C.

BASS CCT La) see a WLI aca 3515 Prytania Street, New Orleans, La.

BAUSCH, PUD MARDEN) Obie Aisa) ee Ere aias, 179 N. St. Paul St., Rochester, N.Y.

BAUSCH | WEEETAMAN SS. ayaa Sep aun eeu RO St. Paul St., Rochester, N.Y.

BRAN HACIVIE IMPALA Sensis ie ree air at cea e 2811 Benvenue Ave., Berkeley, Cal.

IBECK AW IEETAM PARNIMIES Gs Onn eae rue ee rs oe ae St. Mary College, Dayton, Ohio

BENNEHOFE. Hl MESt eed Seas tee niin Laue gneLn tdele Alfred College, Alfred, N.Y.

BETIS CORN (De UL tere satis i ah en tL 111 Market St., Camden, N.J.

Biper, (Pror EAS SCA: DE COOK naar te 744 Langdon St., Madison, Wis.

BrACK, Fs MD cA Dit ial pte chante cine Niet ate ale 530 Wilson Bldg., Dallas, Texas

Boore, Mary A; J POR MLS) FaR IPS (82 0: 60 Darmtouth St. Springfield, Mass.

BOYER CAS s VASNT A 19 Dei Una neti) onl 6140 Columbia Ave., Philadelphia, Pa.

BREWSTER AS WE UB sie) uO) sae elt nn sea ae 57 Water St., St. Augustine, Fla.

IBRODEWEHOWARDY Os Enel seer anenae 433 E. Alder Street, Walla Walla, Wash.

Brooxover; iCaas. A.B.) M:S;, 7052. .8¢ 0224. Univ. of Louisville, Louisville, Ky.

BROW NWACICE AG MAO UN oe EM nme tal Kas. St. Ag. Col., Manhattan, Kas.

BROWN YER RORAMB Ed De te eh auton satin Uys William Nast College, Kiukiang, China

BROWNING, SIDNEY Howarp,’11........ Royal London Ophthalmic Hospital, London

IBRUUNW CHART ES AC olsBs 716s en). nee 314 Reliance Bldg., Kansas City, Mo.

BRYANT, Pror. Fart R., A.M., ’10........ Muskingum College, New Concord, O.

BULLS AAMES PE DGAR® JHSON O25 ene 141 Broadway, New York City

BULEITT, (PROF. (i/o. MCAS. Mes 212 ob ne eee ate Chapel Hill, N. C.

BUNKER GEOG. . (Bass li fig calico tin ad te sake ck eM ee Gatun, Canal Zone

IB URE GE SL TA eke or pm ap RY eeeelin perk Unrate ie Kleber Hodsell, Rawlins, Wyo.

ETS WiEIe a AGI TlenaVE DN eal ebay tee Pan nn ant eae Columbia Univ., New York City

CABATEERO, Pror., Gustav A., 716. 605.0208 6s: Fordham Univ., New York City

CARTSON, | CAO ABs PG ee Lie hia Zea Ly ae ta ne ee Doane College, Crete, Nebr.

CARTER PROF! CHARTERS white atest. Mee ae Parsons College, Fairfield, Ia.

CARTER JOHN He ;GOn erate an ae 5356 Knox St., Germantown, Philadelphia, Pa.

CRAMBERS WEE TC We Cee ee ha Dept. of Agriculture, Washington, D.C.

CHESTER, WAYLAND Morcan, M.A., ’15...... Colgate University, Hamilton, N.Y.

CaTCKERTNG: HA VE. (ASE. ENG ihc eehic el Pl ten let e be eel een ale es Albion, Mich.

Crark Grorcre Epw:, M.D 29622. 5.60 2505 ue Genessee St., Skaneateles, N.Y.

CEARKGVETOWARD, W)), CAUIMES 20 DAE Canes e. um lie ean eit eth ei mp a Fairport, Iowa

CLEMENTS MRS?) PE PRD 0S Ore ee eed ete a ia Tucson, Ariz.

COBBABNE TAL SP Ri Dy Patt we smut ras breve n ey 7 ee ean Falls Church, Va.

Coch, -Pror..Grorce EB), Ph.D 7115. ee R.F.D. 9, Lawrence Kas.,

CoLron, Harorp S; Ph.Ds 714 ue Zoological Lab. Univ. of Pa., Philadelphia

Cone wAlbertAl? sos av aeaitlea ee ton ane Editorial Staff, ““Lumberman,” Chicago, Ill.

CONnGER, (AT EEN IC MEA 15.) ected ate P.O. Box 663, East Lansing, Mich.

CONEON, JAMES JVPbeDy, 744s Ro! eee 717 Hyde St., San Francisco, Cal.

AMERICAN MICROSCOPICAL SOCIETY 307

Cooper, ARTHURR., A.M., Ph.D.,’16..... College of Medicine, Univ. Ill., Chicago, Ill.

CORNELL) UNIV VLEIBRAR YI (BROFMS SIE GAGE) ose mies a eve tane Ithaca, N.Y.

ORT AW Wie Pee danse U Nas elshabelctaey Ni epetaietaltatante anal unbi st eh spel eer spene tele Bain

Mets e 8) sila callai sioner eet J.H.U. School of Hygiene, 310 W. Monument St. Baltimore, Md.

Corr, (GEORGES Malte severe Maeuaienay cores 1001 Main St., Buffalo, N.Y.,

COVEY, GEORGE Wap eden Ae een ete be iena/aic alhedaiuvetcvele eaieatel dere te petatonaye College View, Nebr.

DARBAKER LEASE RODIN PhD) VETS) PAB ii oe inate anean dal aete SIS) hats slat oa eran

CE POA SAMAR Tes oehy Ceasar 7025 Hamilton Ave., Homewood Sta., Pittsburgh, Pa.

DAVISIPROR EES e EHD sil Zac aela alien University of Florida, Gainesville, Fla.

Dene, Ewre Oar, ACM.(S.M.5 713.8) ue. Bethany College, Lindsborg, Kans.

EEE RELI NOD Oe re Oe SO euler P.O. Box 313, Scottdale, Pa.

DP VVEED CHARTS ET IMES eA ly 2. ene 355 College Ave., Valparaiso, Ind.

IDISBROWs VW ELETAM, Se MED Ph G01 es). 22.0 151 Orchard St., Newark, N.J.

DWODGEY) CARROT AVG mee) ie ee Cis a ta lei Brown Univ., Providence, R.I.

DOUBENA EDWARD Shes OOMayiuen wane Waris 3613 Woodland Ave., Philadelphia, Pa.

Dousiepay, ArtHuR W., M.D., 716....... 220 Marlborough St., Boston, Mass.

DRESCHERI Wa Oiiieleca ans el: Care Bausch & Lomb Opt. Co., Rochester, N.Y.

IDUBES SER WESWALBER TA aLONecmiecaticiey ccci ile ta hace almnane thd CoML NaQGel Net Ransom, Kas.

DUNCAN PRO RAE INE WE Head Gite ash wees ina Ae So. Methodist Univ., Dallas, Tex.

DDN w VETTE TON LI WVeeiyilelisiyaverer rol nrepoiencusyay. U. S. Ammonium Plant, Perryville, Md.

DD VA SANTO, BALAK al RU amr MAIN ERte RIN Ally. At ts oy aay ey aa Lag A ee aA a eA Tower Hill, Il.

BPMONDSON,, CHARLES) Ea (PHU APS) reine ae College of Hawaii, Honolulu

HGGEESTON WEL: Re INIA MS iia Mian) ada elias outa Marietta College, Marietta, Ohio

IBIGENMANNE ER OFS CEL 95 )ivil) Sanya mauia Mma W HUTS 630 Atwater Ave., Bloomington, Ind.

PESTO TP RANTS HER IVICA Sa Tyg ea aRU arn ale OC 324 Kinsey St., Richmond, Ind.

Bis PROr MEME Ph Dit a as Dept. Physiol. University of Mo., Columbia, Mo.

Exrop, Pror. Morton J.,M.A.,M.S.,’98..University of Montana, Missoula, Mont.

ESSENBERG, Mrs. CHRISTINE, M.S.,716............. Scripps Institute, La Jolla, Cal.

BSTERE VAC ATH VANI OVS? Lai eo) kige ee crew ave ua aoniet Oe Occidental College, Los Angeles, Cal.

IB irae Oli) Wee eles) MED: IMIS 0. BW REIMIE GY POO Ny ein aD En enue panel Uhid aa

3 5 ahd CHR OA Oe eC AUT ACS AS A Guy’s Hospital, London, S. E., England

ARTO UE ROR. Wis Gail nt oye c eRe ies 24 Quincy St., Cambridge, Mass.

ARMERA ERATE Mis ANB TT Oi ype Cn Pte Me es ana Beloit College, Beloit, Wis.

PATIECw ROR ME We BO MSs cid oie are me ce P.O. Box 315, Gainesville, Fla.

PELLows, CHASiS., FRUMLS..\783 552s 46 107 Cham. of Comm., Minneapolis, Minn.

FERNANDEZ, FR. MANUEL, B.S., 716....... San Juan de Latran College, Manila, P.I.

FISCHER CAL Iss oh) 2 Sarva ele ULC MN la ee aie Ie ae Box 1608, Milwaukee, Wis.

mz WANDOLPH, RAYMOND Bi RoOMeS 201 aoe Rau ey en amu ciate: we vara sepa sets la ates

3,0 ad Ps RUE ETE PCE PRE Desa Ue Oe fa Ce State Laboratory of Hygiene, Trenton, N.J.

RENE ARERS MEO MEDS OU ois, Kadi N anaes Stoneleigh Court, Washington, D.C.

LOKGYOMES.” iy ASR WY) Eel D8 it ON LAR IE Hie IS RvON eer 202 S. Thirty-first Ave., Omaha, Neb.

HOSTER MEE TANT eV 211G so ci a2 ctelenc rater nel i cera 707 Coleman St., Easton, Pa.

PURNISS eEeuvve, MED. PhD, 7055... cicadas gels te 56 Brazos St., Hartford, Conn.

308 LIST OF MEMBERS

GaABRInie VAS AAG Se selec tle 2659 California St., San Francisco, Cal.

GAGE JPRGESSIMONPEL:, B.S, O2e\e% etek ee eek eee ee 4 South Ave., Ithaca, N.Y.

GatLtoway, Pror. T. W., A.M., Ph.D., ’01...347 Madison Ave., New York, N.Y.

GARRETSONY BUGENE S12 nite mess eee ie eee aac 428 Fargo Ave., Buffalo, N.Y.

Grae Tyee Ph Delo es ole Biology Building, U. of Wis., Madison, Wis.

Gorpsmrrns cGy We Bel 213 2a span ava mentee ei oats Station A, Lincoln, Nebr.

GOWEN-WPRANCIS eA Nos ietnws ceaaie ase eee oes R. D. 1, Box 14, Exeter, N-H:

GRAHE OHNE yl OMe smart tclekts Research Dept. Brown Company, Berlin, N.H.

GRAHAM ACHARTES Wi, Mc. 300s coe oo eee nee 447 W. 14th St., New York City

GRATAMJOHNG YOUNG, Phi Dy la Terra taeidepicci ace ieeerciee University, Alabama

(Grane \Wiinnd (Canning Mla aa nao eGo ugsobaddoc Lock Box 223, Tama, Iowa

GRIFFIN, WA WRENGE Beno l Seance sie ete University of Pittsburg, Pitttsburg, Pa.

GUBPREETSOHNGH = Hebb nee eee eee ae A. & M. College, Stillwater, Okla.

GuyEr MicHAET EP her lear aninyan University of Wisconsin, Madison, Wis.

HUAGETSTEENS ROBERT it OM eiP er rarer riers Wie a ner ice Minneola, Nassau Co., N.Y

FVACUE PRLORENCE WAC My llOne cig. serie =e eine eee Nat. Hist. Bldg., Urbana, Il.

PATSE + GREGORW IBIAS ly tele kee oat e ae tld sacle Milton College, Milton, Wis.

VANCES OBMRTaileee ye Neel Gina areysy crete are ae Zool. Lab., U. of Pa., Philadelphia, Pa.

ETIANTRAINSON# aera bapa en OSipsye ct cictass scuey’1<se veyosous vere vege cist leraiere aieion terete Charletson, Ill.

EUANITAHSIMIAR GAR mT IEE VAGME OE cei sa cies iee sc ace ciel Station A, Lincoln, Nebr.

IEVANSEN JAMES SS HO nea wel eevee sc teem ine St. Johns Univ., Collegeville, Minn.

PAR D YAMS GRIN WEL er aeVarejersve sis) ele) syste s 436 E. Michigan Ave., Indianapolis, Ind.

FARMAN OIMIAR Vel tL Si or eee Kansas State Agr. College, Manhattan, Kansas

LAV DEN SE ORACE ID WIN) Reel 4ee ees eecere reece College Station, Tex.

JR GaN 10, ID aldol DEO e ee oe dood o adn Wash. State College, Pullman, Wash.

EMPATHAROV PRANKLING MSG. 71S aelacise ace Polytechnic Inst., Billings, Mont.

HrIMBURGER, HARRY Vi. ABs 1450. 5. cscs 1625 Wesley Ave., St. Paul, Minn.

HinDERSON,) WiLEDTAMHe user as epae ata cianere Millikin Univ., Decatur, Il.

Eee Ton aWaenraMe Aj PHA. 25 ce et eae sere ioeiee aes Claremont, Cal.

Hy ORTHAMICUDVIGE Cs) 02 Se eet ers Meadowdale, Snohomish County, Washington

Hoty Cross COLLEGE, PROFESSOR OF BIOLOGY................--- Worcester, Mass.

TOPKINS RANK NBs) (Be Ses Oni al car aleree ay etyci oie ere) a senate North Salem, Ind.

FET OS RAIN SEW A/D ttl crete van ctsne tae aneioee pel oeitoes eaeeitel eal Nae 49 6th St., LaGrange, TI.

Howarp, Rospert Nessit, ’12...Ookiep, Namaqualand, Cape Province, S. Africa

HOWwiAND EENRY. Re wAUMiE. 98h seinci cirri cits 217 Summer St., Buffalo, N.Y.

PU GHES SO ALLY (Pos TO Aen rien isis ceie erste sansa Grinnell College, Grinnel, Ia.

IvESMEREDERTCIE (OD pram stay ccetetoateyreyicve reels saetoter 1201 Race St., Philadelphia, Pa.

Jreersitepror Rs Bs Uae Be sentria Univ. of Okla., Norman, Okla.

PENNER ME tA IME AL Dy eee eee eto winters Maier cleie ek Science Hall, Indianola, Ia.

JOHINSONS (BMAD oe iene Meet aie kel sit are ce ea re detenee «tests Joplin, Mo., R.F.D. 4-147

JOHNSON} MRANKIS UME), (O32 et seis unbiarcne oeien 829 Adella Ave., Coronado, Cal.

JORDAN SER OM MEI Ey 2 gare ae Nae ye er eee University Place, Charlottesville, Va.

UDA CHANGE YA O0ME eee ere a secicrr Biology Bldg., U. of Wis., Madison, Wis.

KErNATLMORRISG. Acne sista eiieinerteeraicieletereicr er: Bismark, No. Dak.

AMERICAN MICROSCOPICAL SOCIETY 309

KSINCATD TREVOR, As Mes U2 oie cle cre cielerete ls University of Washington, Seattle, Wash.

KING GENE ZS BYS: isl dat ere tiey voveray 8 er erey Sey) arses elers Phillips. Univ., Enid, Okla.

Kirscu, Pror. ALEXANDER M., M.G., 716............. Notre Dame (Univ.), Ind.

SPINE DINGT) EE RALANS Hl Oe mraia roetraciepelsiapereyeselsle lester: 836 So. George St., York, Pa.

KON TG HiT Byars vise ae Were yes uta, Conver een iene eel 1015 Blondeau St., Keokuk, Ia.

Korom, CaArtrs A-SPh.D:, 7990.08 ek University of California, Berkeley, Cal.

TROT Z Ae Ne piesa NAD) Bets O Mae a eae ens tc este hee ok eteeh nett 32 S. Fourth St., Easton, Pa.

ONS GG BENS MID pSRIES Re ibs etter ecararevero cleketsuepereiene Univ. of Arizona, Tucson, Arizona

KRECKER, FREDERIC H., Ph.D., ’15........ Ohio State University, Columbus, Ohio

NGACVEVIORANTEAW sy) (14: 352) coca sis mis patie! ote U.S. Naval Hospital, Las Animas, Colorado

Lampert, C. A., 712...Bank of New South Wales, Warwick, Queensland, Australia

ID NSTDE, 118 ell s Ih Aaa iene ts ae Ornate ROS erie MRE Univ. of Okla., Norman, Okla.

PANTIE Z Ae OERU SUV ese eI oar 7 LOcisasstachsss ist sreloh eral 1s) seca shake skekct omnes steer Seas Mie Mound, Ill.

ANU GRORGEVR,) Phebe tile see. University of Michigan, Ann Arbor, Mich.

GAA SIMISS ViecAG Vie DS. EUR MLS. 2880. tae Gee wes) uia cel cere eseier ops iaeroherre

“15.36 Qrckopol BSAC OR ELSIE Tic E RISER EEE 1644 Morse Ave., Rogers Park, Chicago, Tl.

TAT IOER +) LLOMER) bese Ame ub Ee nike ai 0h oe Saker aes 1226 So. 26th., Lincoln, Nebraska

LEWIS lyn THOR EMAN Enel) s iT ON.jseieis wt nie bias. leas be avec Sod University, Va.

JER WAS, IMERS IGATHERINE UB 100%: ws clo ss erat ale a: Bellwood Farms, Geneva, N.Y.

TETERE ROW MM AGIVi. McD) ei OOM aa nite aae uiecbU amit cioka etelea ane 4 Nashville, Tenn.

OMB SADOLPH OD) coe vena de mau Lent m ayia: 289 Westminster Road, Rochester, N.Y.

LONGFELLOW, RoBEerT Capies, M.S., M.D.,’11........ 1611 22nd St., Toledo, Ohio

COWDEN MERU GHD a3 LO Marrs ia hates AEMtec ae ve 1312 York St., Denver, Colo.

Mower EP yen HEE ANORD C2 1710 Bari acy see ital Ch pert ay een ts 1826 D. St., Lincoln, Nebr.

VON ELOWARD) Ney MIDE B42 tenis ee eee ee 828 N. Wheaton Ave., Wheaton, Ill.

MacGiriivray, ALEXANDER D.,’12.......... 603 W. Michigan Avenue, Urbana, Ill.

Mack, MarGARET ELIzABETH, A.M., ’13............ Univ. of Nevada, Reno, Nev.

Jy} Ya EY Nags 9 Beso] Boel TAM Wena Bl ta BD Yea US a al ie Pe at eae Mayo Clinic, Rochester, Minn.

WARE GORGE JEENRY. Meee iit) one ey nia 94 Silver St., Waterville, Maine

NWARSHATT COLLINS, MD 96. 204. cen ao ee 2507 Penn. Ave., Washington, D.C.

MENRSHADT. RUTH: PH D707. si... a oeiaemieniae ete Lane Technical H.S., Chicago, Ill.

I LATRG TE OES GIS 2 018) Bn IP oe is eet ts 139 E. Gilman St., Madison, Wis.

Marrianp, Harrison S., A.B., M.D., 714............ 1138 Broad St., Newark N.J.,

NVATHERS Baie Ds PhsDs 02h... 00,.necenee 228 Gratiot Ave., Mt. Clemens, Mich.

WAAR ELEN Va GUSTAV ay HED) est 21 Sheste tsa. ors aie ier aerate Miss. College, Clinton, Miss.

VIA EE We SR OM Mc Stoo LOR bats cra al ocihentrel neces Wesleyan College, Warrentown, Mo.

MAY WALD EREDERTCKIJ S020 10%. \cjcces ele eee 222 Grahd Ave., Nutley, N.J.

IMGCREBRVAIGEOS Gn USiec, 2 ioe eestor ue ee 110 Nevada St., Carson City, Nev.

INTE WANE PAW SUSIE cccrtfathicinte/s\ ial s clecdeleeeaieeee 1118 Marbridge Building, New York

IVICA JOSEPH: | O4 5)0 5.01: esas w asics deine teen ee 259 Eighth St., Troy, N.Y.

Mekrrver. Prep 1.) PIRIM-S:! 706)... 3-2 25-- P.O. Box 210, Penticton, B.C.

IMIGIHAUCHEING AT VAHUR MEALS LS. cic sc acclarcreicemmetarerecr cata orsya ate Pullman, Wash.

310 LIST OF MEMBERS

MEREVNOLDS) LOUIVERAVA BY 1G yore ahicleisiaiis eletets lee een Ing Tai, China

MGWHIELTAMs, JOHN: 4 ee ee Rey nye ela. Lock Box 62, Greenwich, Conn.

Mercer, A. CLirForD, M.D., F.R.M.S., ’82....324 Montgomery St., Syracuse, N.Y.

MERGERS IWas (PBA OO.) cist Vea uCuhen Ls aate ws 200 E. State St., Athens, Ohio

Mertcarr, PRor, ZENO P., BiA., 712). 35.2.2. Col. A. & M. A., W. Raleigh, N. C.

Minter CHARGES BL 7103.0 Snise% Med. School, John Hopkins U., Baltimore, Md.

Mute: Joan Aly PhD), RMS... 789 )2):\..5-/..5.)- 44 Lewis Block, Buffalo, N.Y.

MOCK TT ye vEe SRE OLE Sc aero emis cise sic ei ese 2302 Sumner St., Lincoln, Nebr.

MonrTGoMERY, CHARLES S., 719.............. 420 Riverside Drive, New York, N.Y.

Moony, ROBERT 'P..M.DS (OF 8. ii. Seer Hearst Anat. Lab., U. of Cal., Berkeley, Cal.

MorcAan, ANNA HAVEN, Ph.D.,’16............ Mt. Holyoke Coll., So. Hadley, Mass.

Murers VP RANIC Js. iLoncbins pikes teen 15 S. Cornwall Place, Ventnor City, N.J.

INESBED ROBE Avni Om nae te ciee eiciiate citevels = Box 1171, Sta. A, Lincoln, Nebr.

INOS WELT AINE, | CACM IS eee a clits ataye nie) o:ord orale stone) cyttos Pel ove eho erate fe Genoa, Nebr.

INOREIS; PROF EVARRY | WALDOy MEI T ict cei si pian eel 816 East St., Grinnell, Iowa

NORTON; (CHARLES) EMD aa or oe en oinlels sje 2.0 evs 118 Lisbon St., Lewiston, Me.

OGERVER SC. 53 fb 5 SCH ho a tae on Hs elciis aie els = ste ve 1006 N. Union St., Lincoln, Ill.

OsBorn, Pror. HERBERT, M.S.,’05..........-. Ohio State University, Columbus, O.

Vr EVARIVENING, NIE (OS 2c ccsks oii gk %s a Store opeisiel sym Spencer Lens Co., Buffalo, N.Y.

PAGE oR WaNe MELB ENIEG 81d cele tei icc ole (s'sca1A= = lal 2) 810 University, Ithaca, N.Y.

PATRICK) PRANK IE DD) e779 0 si.) sks (alesis iene, asorolebielals 421 Bonfils Bldg., Kansas City, Mo.

IDE AGH OH RED IN 10 Lapses sie alarenictee lee mtel evel stanetee P.O. Box 503, Altoona, Pa.

PEER (GEORGE GOSE, AC Mi doc. sie ceiesleie)nceine ie ie aie Eire Salem, Virginia

PENNOCK EDWARD; (19 setinc cicteiheinniactctets 3609 Woodland Ave., Philadelphia, Pa.

PER YAM AU HOS? Wei Wil a, 14 iatsclcis aloo la\ale iso aie atedsieielela im sfeun = Encampment, Wyoming

PETERSON | NIELS PREDERICK U1 2 oo teers opt nie irae Box 107, Plainview, Nebr.

Poem Magrinj:, MS:01602 0. cies. c. 25th St. & California Ave., Omaha, Nebr.

PrATEGel as: PhDs Oe esl tet aeyeeeteliets 561 W. 141st St., New York, N.Y.

PETE SEWARD, “lly eters sicher as Brandhock, Gerrard’s Cross, Bucks, England

Proucu, Harotp H., A.M., ’16....... Dept. Biology, Amherst Coll., Amerst, Mass.

PORT AIGHN CA) Ra Lie altoids rota s ole tonianlaiaiee meteors 204 N. 10th St., Easton, Pa.

POOL ANCANMOND sfc, NID), ol Ojo nti niche ereejoieta ee is aisle ol Station A, Lincoln, Nebr.

Pounp, Roscor, A.M., Ph.D., ’98....... Harvard Law School, Cambridge, Mass.

ROWERS ENE WA Bs: ADE oo ice tiatetne eels sreyols eres 508 W. 114 St,, New York, N.Y.

PRAEGER AWIMG) Es Oster ernieuaiencistaelsicrsicletel 421 Douglas Ave., Kalamzoo, Mich.

PROBST RE Ve EEOPOLD, G9. jie /-10) eiola sietel=(olelelseis St. Vincent College, Beatty, Pa.

PROCTERS WILLIAM, (Ph Bs) (19 es ache rer el siaiee 149 Broadway, New York, N.Y.

PURDY) WILEIaM C.. MSC AG a nels seine alas 3rd & Kilgour Sts., Cincinnati, Ohio

Quiiian, Marvin C., A.M., 713...........-+----+-:- Wesleyan Col., Macon, Ga.

RAIN WAS EER IMS, 71S ee ale acs asiscierene Princeton University, Princeton, N.J.

Ransom, BRAYTON H., 99..... U. S. Bureau of Animal Industry, Washington, D.C.

Recror, FRANK Lestir, M.D., 711........ 00.2... 227 Fulton St., New York City

AMERICAN MICROSCOPICAL SOCIETY 311

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INDEX

Abbot, Reactions of Land Isopods to

Light, 30

Acanthatrium Nycteridis, Nov. Gen.,

Nov. Spec., From the little Brown Bat,

A New Trematode, 209

Age and Fertility in Fowls, 240

Amebas, Crystals in, 26

Americanus, Camallanus, 49

Amoebas Infesting Man, The, 40

Animal Conduct, Forced Movements,

Tropisms, 295

Ant Destroying Sound Wood, Carpenter,

243

Ants, Trophyllaxes: A Nutritive Ex-

change Among, 244

Antheridia on the Prothallia of Some

Homosporous Leptosporangiate Ferns,

The Distributi, the Archegonia

and the, 271

Aphids, Wing Development in, 33

Applied Eugenics, 258

Arachnida, Gynandry in, 36

Arcella Excavata nov. sp., 242

Archegonia and the Antheridia on the

Prothallia of Some Homosporous Lep-

tosporangiate Ferns, The Distribution

of the, 271

Arrhenurus, New Species of Water Mites

of the Genus, 275

Ascaris, Life Behavior of, 29

Association in Fishes, Color Discrimina-

tion and, 239

Assortive Mating in Chromodoris Zebra,

Bark-beetles, Canadian, 292

Bat, a New Trematode, Acanthatrium

Nycteridis, Nov. Gen., Nov. Spec.,

From the little Brown, 209

Baumberger, Nutrition of Insects in

Relation to Microérganisms, 245

Bermuda, Frogs and Toads in, 236

Bilharziasis, 41

Biological Manuscripts, Illustrating, 1

Biology, Recent Changes in Illinois

River, 235

Bone, Effect of Strain on Development

of, 31

Bread Yeast, Some Experiments Con-

ducted with Pure Cultures of, 221

Brine Freezing, New Process of Keeping

Fish by, 240

Brown Bat, A new Trematode, Acan-

thatrium Nycteridis, Nov. Spec., Nov.

Gen., From the little, 209

Bryozoa, The Preservation of Fresh-

Water, 217

€

Camallanus americanus, 49

Camouflage in Reef Fishes, 30

Campodeiformis, Grylloblatta, 293

Canadian Bark-beetles, 292

Carbon Dioxide Produced by Protozoa,

Measuring, 42

Carpenter Ant Destroying Sound Wood,

243

Caterpillars, Locomotion of, 34

Caudell, Zoraptera, 34

Causes and Course of Organic Evolu-

tion, 259

Chickens, Sex Ratio in, 240

Chironomus Larva, Physiology of, 32

Chromodoris Zebra, Assortive Mating in,

Coccidae, Staining, 294

316

AMERICAN MICROSCOPICAL SOCIETY

Coleoptera, Somatic Chromosomes in, 36

Collins, Moult and Regeneration of

Pelage in Deer-mice, 238

Color Discrimination and Association in

Fishes, 239

Coloration, Experiments on Protective,

239

Comstock, Terminology of Metamorpho-

sis, 38

Continuous Variation, and its Inheritance

in Peromyscus, 238

Controllers of Somatic and Psychical

Qualities, Gonads as, 237

Course of Organic Evolution, The Causes

and, 259

Crozier, Assortive Mating in Chromo-

doris zebra, 30

Crystals in Amebas, 26

Crystals, Preparing and Mounting Slides

of, 41

Crystalline Style of Lamellibranchs, The,

Cultures of Bread Yeast, Some Experi-

ments Conducted with Pure, 221

Cunningham, B., Arcella Excavata Nov.

Sp., 242

Deer-Mice, Moult and Regeneration of

Pelage in, 238

Determination of Pale Spirochetae, Sim-

plified Technic for, 39

Development of Bone, Effect of Strain

on, 31

Development of Flesh Flies, 38

Diatoms—New Genera and Species, 283

Diurnal Migrations of Various Plankton

Animals, Reactions Underlying the,

241

Drosophila in Bottled Certified Milk, 244

Drosophila and Disease, 292

Du Porte, Propleura of Orthoptera, 293

Earthworms, Revivification of Exsic-

cated, 28

317

Ectoparasite, The Occurrence of Try-

panoplasma as an, 20

Editor, The New Secretary and, 291

Enlarged Photographs in Forensic Medi-

cine, 40

Entomological Abstracts, 32

Entomological Abstracts, 292

Entomophthorus Fungus, A Peculiar, 263

Epithelial Movements in Vitro, 32

Esterly, Reactions Underlying the Diur-

nal Migrations of Various Plankton

Animals, 241

Eugenics, Applied, 258

Evolution, The Causes and Course of

Organic, 259

Euphorbia, A Flagellate Parasite Occur-

ing in a Species of, 41

Experiments Conducted with pure Cul-

tures of Bread Yeast, Some, 221

Experiments on Protective Coloration,

239

Farlow, Dr. W. G., Necrology, 304

Faust, E. C., A New Trematode Acan-

thatrium Nycteridis, Nov. Gen., Nov.

Spec., From the little Brown Bat, 209

Faust, Montana Trematodes, 27

Ferns, The Distribution of the Arche-

gonia and the Antheridia on the Pro-

thallia of Some Homosporous Lepto-

sporangiate, 271

Fertility in Fowls, Age and, 240

Fertilization, Problems of, 246

Filariasis, 41

Fish by Brine Freezing, New Process of

Keeping, 240

Fishes, Camouflage in Reef, 30

Fishes, Color Discrimination and Asso-

ciation in, 239

Fishes, Food of Young, 241

Flagellate Parasite Occurring ina Species

of Euphorbia, 41

Flesh Flies, Development of, 38

Food of Young Fishes, 241

318

Forbes, and Richardson, Recent Changes

in Illinois River Biology, 235

Forced Movements, Tropisms and Animal

Conducts, 295

Fowls, Age and Fertility in, 240

Freezing, New Process of Keeping Fish

By Brine, 240

Fresh Water Bryozoa, The Preservation

of, 217

Frogs and Toads in Bermuda, 236

Further Studies on North American

Mesenchytraeids (Oligochaeta), 175

Fungus, A peculiar Entomophthorous, 263

Gage, Glycogen in the Nervous System,

Gage, Method for Demonstrating Glyco-

gen in Tissues, 42

Gage, Staining Coccidae, 294

Galloway, T.W., The New Secretary and

Editor, 291

Gardiner and Nuttall, New Process of

Keeping Fish by Brine Freezing, 240

Garrey, Light and Muscle Tonus of

Insects, 35

Gatenby, Polyembryony in Insects, 34

Gilbert, E. M., A Peculiar Entomoph-

thorous Fungus, 263

Glaser, Immunity Principles in Insects, 34

Glycogen in the Nervous System, 31

Gonads as Controllers of Somatic and

Psychical Qualities, 237

Graham, Carpenter Ant

Sound Wood, 243

Grylloblatta campodeiformis, 293

Gynandromorphism, 37

Gynandry in Arachnida, 36

Destroying

Hart, Pentatomoidea, 292

Henderson, W. F., The New Treasurer, 25

Henderson, W. F., Some Experiments

Conducted with Pure Cultures of

Bread Yeast, 221

INDEX

Hoy, Somatic Chromosomes in Coleop-

tera, 36

Howell, Effect of Strain on Development

of Bone, 31

Hull, Gynandry in Arachnida, 36

Hungerford, Oviposition of Notonectidae,

Hungerford, Nematode Parasite of Sciara,

292

Hymenoptera, Sex Determination in, 33

Illinois River Biology, Recent Changes

in, 235

Illustrating Biological Manuscripts, 1

Immunity Principles in Insects, 34

Inheritance in Peromyscus, Continuous

Variation, and its, 238

Insects, Immunity Principles in, 34

Insects in Relation to Microérganisms,

Nutrition of, 245

Insects, Light and Muscle Tonus of, 35

Insects, Polyembryony in, 34

Isopods to Light, Reactions of Land, 30

Jackson, F. S., The Preservation of

Fresh-Water Bryozoa, 217

Johnson, Popenoe and, Applied Eugenics,

258

Kunkel, Development of Flesh Flies, 38

Lamellibranchs, The Crystalline Style of,

Land Isopods to Light, Reactions of, 30

Larvae, Olfactory Sense in, 294

Lateral Lines of Polyodon spathula, The,

189

Latham, Notes on Technique, 38

Latimer, The Lateral Lines of Polyodon

Spathula, 189

Lebour, Food of Young Fishes, 241

AMERICAN MICROSCOPICAL SOCIETY

Lepra, 41

Leptosporangiate Ferns, The Distribu-

tion of the Archegonia and the Antheri-

idia on the Prothallia of Some Homo-

sporous, 271

Life Behavior of Ascaris, 29

Light and Muscle Tonus in Insects, 35

Light, Reversal of Orientation to, 29

Light, Reactions of Land Isopods to, 30

Lillie, Problems of Fertilization, 246

Locomotion of Caterpillars, 34

Loeb, Dr., Forced Movements, Tropism,

and Animal Conduct, 295

Longley, Camouflage in Reef Fishes, 30

Lund, Measuring Carbon Dioxide Pro-

duced by Protozoa, 42

Magath, T. B., Monograph on a Nema-

tode Species, 49

Man, The Amoebas Infesting, 40

Marshall, Ruth, New Species of Water

Mites of the Genus Arrhenurus, 275

Mast, Reversal of Orientation to Light,

Matsumoto, S., Epithelial Movements in

Vitro, 32

McIndoo, Olfactory Sense in Larvae, 294

Mead, Stimuli and Reactions of Sand

Crab, 241

Metamorphosis, Terminology of, 38

Method for Demonstrating Glycogen in

Tissues, 42

Microérganisms, Nutrition of Insects in

Relations to, 245

Migrations of Various Plankton Animals,

Reactions Underlying the Diurnal, 241

Milk, Drosophila in Bottled Certified,

244

Mites of the Genus Arrhenurus, New

Species of Water, 275

Monograph on a Nematode Species, 49

Montana Trematodes, 27

Moore, Gonods as Controllers of Somatic

and Psychical Qualities, 237

319

Mounting in Liquid Petroleum, Further

Notes on, 39

Mounting Medium, 38

Mounting Slides of Crystals, Preparing

and, 41

Moult and Regeneration of Pelage in

Deer-Mice, 238

Movements, Tropism, and Animal Con-

duct, Forced, 295

Muscle Tonus of Insects, Light and, 35

Necrology, 304

Nelson, The Crystalline Style of Lamelli-

branchs, 28

Nematode Parasite of Sciara, 292

Nematode Species, A Monograph on a,

Nervous System, Glycogen in the, 31

Nephrodium Hirtipes HK, Secondary

Prothallia of, 229

Nervous System, The Elementary, 297

Newcomer, Stoneflies and Plants, 37

North American Mesenchytraeids (Oli-

gochaeta), Further Studies on, 175

Notes of Technique, 38

Notonectidae, Oviposition of, 37

Nutrition of Insects in Relation to Micro-

érganisms, 245

Nutritive Exchange Among Ants, Tro-

phyllaxes:, 244

Nuttall, Gardiner and, New Process of

Keeping Fish by Brine Freezing, 240

Olfactory Sense in Larvae, 294

Oligochaeta, Further Studies on North

American Mesenchytraeids, 175

Organic Evolution, The Causes and

Course of, 259

Orientation to Light, Reversal of, 29

Orthoptera, Propleura of, 293

Oviposition of Notonectidae, 37

320 INDEX

Parasite, A Flagellate, Occurring in a

Species of Euphorbia, 41

Parasite of Sciara, Nematode, 292

Parker, The Elementary Nervous System,

297

Pause, Physiology of Chironomus Larva,

Pellagra, 41

Pentatomoidea, 292

Pettey, Gynandromorphism, 37

Photographs in Forensic Medicine, En-

larged, 40

Physiology of Chironomus Larva, 32

Plants, Stoneflies and, 37

Polyembryony in Insects, 34

Polyodon spathula, The Lateral Lines of,

189

Preparing and Mounting Slides of Cry-

stals, 41

Problems of the Future, The, 25

Propleura of Orthoptera, 293

Protozoa, Measuring Carbon Dioxide

Produced by, 42

Preservation of Fresh-Water Bryozoa, 217

Pure Cultures of Bread Yeast, Some

Experiments Conducted with, 221

Ransom and Foster, Life Behavior of

Ascaris, 29

Reactions of Land Isopods to Light, 30

Reactions of Sand Crab, Stimuli and, 241

Reactions Underlying the Diurnal Migra-

tions of Various Plankton Animals, 241

Recent Changes in Illinois River Biology,

235

Reef Fishes, Camouflage in, 30

Regeneration of Pelage in Deer-mice,

Moult and, 238

Reversal of Orientation to Light, 29

Revivification of Exsiccated Earthworms,

Richardson and Forbes, Recent Changes

in Illinois River Biology, 235

Riley, Drosophila in Bottled Certified

Milk, 244

Sand Crab, Stimuli and Reactions of, 241

Schaeffer, Crystals in Amebas, 26

Schmidt, Revivication of Exsiccated

Earthworms, 28

Sciara, Nematode Parasite of, 292

Secondary Prothallia of Nephrodium

Hirtipes HK, 229

Secretary and Editor, The New, 291

Sex Determination in Hymenoptera, 33

Sex Determination in Trialeurodes, 292

Sex Ratio in Chickens, 240

Shinji, Wing Development in Aphids, 33

Shull, Stoll and, Sex Determination in

Trialeurodes, 292

Simplified Technic for Determination of

Pale Spirochetae, 39

Smith, E. A., Illustrating Biological

Manuscripts, 1

Somatic and Psychical Qualities, Gonads

as Controllers of, 237

Somatic Chromosomes in Coleoptera, 36

Spirochetae, Simplified Technic For De-

termination of Pale, 39

Spirochetosis, 41

Steil, W. N., Secondary Prothallia of

Nephrodium Hirtipes HK, 229

Steil, W. N., The Distribution of the

Archegonia and the Antheridia on the

Prothallia of Some Homosporous Lep-

tosporangiate Ferns, 271

Stimuli and Reactions of Sand Crab, 241

Stoneflies and Plants, 37

Strain on the Development of Bone,

Effect of, 31

Staining Technic, Improved, 40

Stoll and Shull, Sex Determination in

Trialeurodes, 292

Sturtevent, Drosophila and Disease, 292

Summer, Continuous Variation, and its

Inheritance in Peromyscus, 238

———_

S21

Swezy, Olive, The Occurrence of Try-

panoplasma as an Ectoparasite, 20

Swaine, Canadian Bark-Beetles, 292

System, The Elementary Nervous, 297

Taylor, F. B., Diatoms- New Genera and

Species, 283

Technique, Notes on, 38

Terminology of Metamorphosis, 38

Toads in Bermuda, Frogs and, 236

Treasurer, The New, 25

Trematode, A New, Acanthatrium Nyc-

terides, Nov. Gen., Nov. Spec., From

little Brown Bat, 209

Trematodes, Montana, 27

Trialeurodes, Sex Determination in, 292

Trophyllaxes: A Nutritive Exchange

Among Ants, 244

Tropisms, and Animal Conduct, Forced

Movements, 295

Trypanoplasma as an Ectoparasite, The

Occurrence of, 20

Vitro, Epithelial Movements in, 32

AMERICAN MICROSCOPICAL SOCIETY

WwW

Walker,Grylloblatta Campodeiformis, 293

Welch, P. S., Entomological Abstracts,

Welch, P.S.,Entomological Abstracts, 292

Welch, P. S., Further Studies on North

American Mesenchytraeids (Oligo-

chaeta), 175

Wheeler, Trophyllaxis: A Nutritive Ex-

change Among Ants, 244

White, Color Discrimination and Asso-

ciation in Fishes, 239

Whiting, Sex Determination in Hymen-

optera, 33

Wing Development in Aphids, 33

Young, Experiments on Protective Color

ation, 239

Yeast, Some Experiments Conducted

with Pure Culture of Bread, 221

Young Fishes, Food of, 241

Zoraptera, 34