On the development, morphology, and economic importance of chicken cestodes

cs” THE DEVELOPMENT, MORPHOLOGY,
ey 1 AND. ECONOMIC IMPORTANCE
"OF CHICKEN CESTODES

‘Morphology of Adult and Larval Cestodes from Haat ite

Studies on the Transmission and Prevention of Cestode
Be BREStERD in Chickens

BY

JOHN EARL GUTBERLET

A.B, Bethany College, Kansas, 1909
A.M. University of Illinois, 1911

THESIS

Kes ‘Submitted in Partial Fulfillment of the Requirements for the »

Degree of

DOCTOR OF PHILOSOPHY

) IN
- THE GRADUATE SCHOOL
: OF THE

: “UNIVERSITY. OF ILLINOIS |
A LSS

“ pe

ie

ON THE DEVELOPMENT, MORPHOLOGY,
AND ECONOMIC IMPORTANCE
OF CHICKEN CESTODES

Morphology of Adult and Larval Cestodes from Poultry

Studies on the Transmission and Prevention of Cestode
Infection in Chickens

BY

JOHN EARL GUTBERLET

A.B. Bethany College, Kansas, 1909
A.M. University of Illinois, 1911

THESIS

Submitted in Partial Fulfillment of the Requirements for the
Degree of

DOCTOR OF PHILOSOPHY

IN
THE GRADUATE SCHOOL
OF THE

UNIVERSITY OF ILLINOIS
1914

st
a4
pg

oy, 21- MIG

MORPHOLOGY OF ADULT AND LARVAL CESTODES
FROM POULTRY*

Joun E,. GuTBERLET

During the course of experimental studies on the life history
of certain chicken cestodes described in the succeeding section of
this work (Gutberlet, 1916) it was necessary to determine exactly
the morphological features of the species, which to be sure, had
been studied by others but were only partially and imperfectly
known. In the former paper I recorded experiments which demon-
strated the intermediate stage of Choanotenia infundibuliformis to
be in the common housefly, Musca domestica, and discussed the
symptoms of infection and methods of control for tapeworm dis-
eases in chickens.

In this paper are taken up the structure of the adult and cysti-
cercus of Choanotenia infundibuliformis (Goeze), and also the
adult form of four other species occuring in chickens of this
country.

As described more fully in the preceding paper the worms
were removed from the intestine under water. The use of normal
salt solution was avoided since it was found to be injurious. The
cestodes were killed in a corrosive-acetic solution and preserved in
70% alcohol and glycerine. Best results were secured by staining
in Delafield’s or Ehrlich’s acid hematoxylin and destaining in acid
alcohol.

The five species discussed here were collected at two widely
separated points, a farm at Hardy, Nebraska, and the poultry farm
at the University of Illinois. These morphological studies were
carried on at the Zoological Laboratory of the University of Dh-
nois. This work was taken up at the suggestion of Dr. Henry B.
Ward, to whom I am greatly indebted.

*Contributions from the Zoological Laboratory of the University of Illinois under
the Direction of Henry B. Ward, No. 57.

24 JOHN E. GUTBERLET

STRUCTURE OF ADULT AND LarvA (CySTICERCUS)
A. ADULT

Choanotenia infundibuliformis (Goeze 1782) Railliet 1896

1. Diagnosis: Length 50 to 200 mm. Scolex (Fig. 2) small,
rounded, or conoidal, about 0.4 mm. wide. Rostellum (Fig. 2, 3, r)
60 to 70u in diameter, armed with a single row of 16 to 20 hooks
(Fig. 8) 25 to 30u long, with long dorsal root and short ventral
root. Suckers prominent, elongated antero-posteriorly, length 180
to 210u; breadth 135 to 175u between the extreme outer edges.
Neck short and unsegmented, somewhat narrower than broad. In
specimens well extended neck much narrower than head. Anterior
proglottids very short and as they become older funnel-shaped,
much narrower at anterior than at posterior margins; posterior
segments 1.5 to 2.5 mm. broad and 1.5 to 3 mm. long according to
amount of contraction, with convex lateral borders, nearly as wide
at anterior as at posterior margin. Genital pores irregularly alter-
nating, situated one in each segment in the anterior third of the
lateral margin, usually under cover of the backward projecting bor-
der of the preceding segment. Vas deferens (Fig. 14, vd) and
vagina pass between excretory canals and dorsal to nerve trunk.

Male Reproductive Organs: Testicles (Fig. 14, t) 25 to 40
or more, 60 in some cases, in posterior half of proglottid, posterior
and lateral to large yolk gland, within limits of excretory canals.
Vas deferens passes forward and in anterior third of proglottid
forms a mass of coils between ovary and excretory vessels from
which it extends outward as a convoluted tube to base of cirrus
pouch. Cirrus pouch (Fig. 14, 15, cp) ovoid in shape, 75 to 95y
in long diameter. Portion of vas deferens in cirrus pouch is much
coiled. Cirrus 50 to 65 long, armed with spines; outer surface of
cirrus pouch forms base of deep genital cloaca.

Female Reproductive Organs: Vaginal opening in genital
cloaca posterior to cirrus. Vagina posterior to cirrus pouch, after
crossing ventral excretory canal dilated to form ovoid seminal
receptacle, posterior and ventral to vas deferens, extending to well
developed shell gland, 40 to 50 in diameter located in front of
middle of proglottid. Transversely elongated ovary (Fig. 14, 0)

MORPHOLOGY OF CESTODES FROM POULTRY ony

occupies anterior portion of middle field of proglottid in front of
shell gland. Large yolk gland posterior to ovary and shell gland,
irregular in shape, elongated transversely, with convex ventral sur-
face and concave dorsal surface. Uterus (Fig. 16, uw) developed
as tube between anterior and ventral lobes of ovary. Gravid uterus
fills up most of proglottid, extending beyond excretory canals on
each side. Eggs oval (Fig. 7), with very thin membrane next em-
bryo, followed by thick, smooth membrane 40 by 32 to 45 by 36h
in diameter, and one or two outer membranes, very thin and wrink-
led in preserved material. Diameter of outer membrane 65 by 40u
to 60 by 45; at each pole of outer membrane a delicate appendage.
Embryonal hooks 184 long. Embryo 32 by 22, in diameter.

2. Morphology: The scolex of the living worm shows up
very prominently and can be used as a distinguishing feature.
When first removed from the intestinal wall the suckers appear
distinct and the neck is much narrower than the scolex. Soon
after the removal it often contracts and takes on the appearance of
a flattened bulb which includes the neck and anterior segments
(Fig. 1). This feature is characteristic of this species and is a
factor which alone assists very materially in distinguishing it from
others that occur in chickens.

The rostrum or crown of the scolex is somewhat pointed when
the rostellum is enclosed within its sheath (Fig. 2). The rostellum
is an ovoid structure with a bulbous expansion at its anterior end.
It has a length of 140, and a breadth of 60 to 65, at its anterior
end. A crown of 18 hooks is arranged in a single row around the
bulbular anterior end. The structure of the wall is of a fibrous
nature and presents a transversely striated appearance due to con-
traction. In the interior of the rostellum the structure is a con-
nective tissue mass with few cells, some of which possess long
processes. The hooks (Fig. 8) are 30u in length with a long dorsal
root and a short ventral root.

The rostellar sheath or sac (Fig. 3, rs) into which the rostel-
lum is withdrawn is oval in shape and 230 to 240y in length by 80
to 90 in width at its broadest point. Histologically, the structure
is that of a fibrous connective tissue type with spherical and spindle-
shaped cells. The cells coming in contact with the rostellum, as

26 JOHN E. GUTBERLET

well as those on the outer edge of the sac, bear long processes. The
outer layer of the rostellar sac is composed of longitudinal and
oblique fibers of a muscular nature which probably have for their
function the movement of the rostellum.

The four excretory canals, that have extended forward through
the entire length of the body, unite in the scolex to form a ring
(Fig. 3, e+), which lies in the tissue of the rostellar sac around the
body of the rostellum. .

The suckers are prominent. They are oval in shape and in
preserved specimens measure 180 to 210 in length and from 135
to 175y in extreme breadth. In the center of each sucker there is
a depression or an acetabulum, 30 to 40y in diameter. The entire
‘nner surface of the suckers possesses minute hooklets or spines
(Fig. 4) 1.5 to 24 long. These hooklets not only line the suckers
but also extend over the entire surface of the scolex (Figs. 3, 5)
and down onto the neck region; they disappear before reaching
the first segment. They appear more distinctly on scolices that are
somewhat contracted than on those that are well extended. These
hooklets can be seen only in sections as they are too small to be
distinguished readily in whole mounts.

Musculature: The longitudinal muscle fibers are arranged in
bundles which are scattered, forming a loose irregular layer. The
bundles are numerous and nearly of a uniform size. There are no
transverse muscle fibers present except a few minute oblique fibers
which connect some of the longitudinal fibers near the ends of the
proglottids. Some dorso-ventral fibers are present, but they are
not abundant.

Nervous System: The longitudinal nerve fibers are arranged
in fiber tracts which approach the structure of a nerve cord. The
individual fibers do not form a compact mass, but are more or less
free in the tract. Nerve cells have no definite arrangement, but
are situated irregularly along the fiber tract (Fig. 6). The nerve
cells are somewhat spindle-shaped and quite large, being from 20
to 25u long by 6 to 8» wide with large nuclei. Transverse nerves
are composed of individual cells with long processes extending
transversely from the lateral fiber tracts. The transverse fibers are
much scattered and have no definite arrangement except that they

MORPHOLOGY OF CESTODES FROM POULTRY 2h

are more numerous near the ends of the proglottids. Peripheral
nerve cells are widely and irregularly distributed. They are more
numerous at the anterior end of the proglottids, especially on the
portion that is covered by the backward extension of the preceding
segment.

Excretory System: The excretory system is fairly well devel-
oped in this form. The ventral canal (Fig. 14, v ex) is the larger,
and has a diameter of 28 to 30u. A transverse canal unites the
two longitudinal canals in each segment. The dorsal canals (Fig.
14, d ex) are much smaller, having a diameter of 6 to 8» and are
not united by transverse connections. The four longitudinal canals
extend anteriorly to the scolex where they unite to form a ring
which lies in the rostellar sheath around the body of the rostellum.
The vas deferens and vagina pass between the dorsal and ventral
excretory canals.

Male Reproductive Organs: The testes vary in number, us-
ually from 25 to 40, but in a few cases the number is much greater,
being as high as 55 or 60. The testes are quite large, being from
40 to 554 in diameter, and are located in the posterior half of the
proglottid (Fig. 14, ¢), posterior and lateral to the yolk gland. The
testes are not arranged in layers, but are grouped in a more or less
compact mass almost entirely within the limits of the excretory
canals. The vas deferens (Fig. 14, vd) in the anterior third of
the proglottid forms a coiled mass at the side of the ovary, from
whence it passes laterad to the cirrus pouch as a convoluted tube.
The portion of the vas deferens inside the cirrus pouch is coiled,
varying in extent in different specimens (Figs. 14, 15). The vas
deferens passes into the cirrus. There is no seminal vesicle formed
by the vas deferens in the cirrus pouch nor are there any accumu-
lations of sperm cells. The cirrus pouch (Fig. 15) is ovoid in
shape and is from 75 to 90u in diameter. The wall is made up of
layers of fibers which are both circular and oblique, forming a
basket-like network which incloses the cirrus and a portion of the
vas deferens. The outer wall of the cirrus pouch forms the inner
wall of the deep genital cloaca. The cirrus is a compact structure
from 50 to 65y long and lined with spines. It is a slightly curved.
structure passing from the cirrus pouch and curving posteriorly

28 JOHN E. GUTBERLET

toward the vagina which is directly posterior to it. The cirrus was
not observed extending from the genital cloaca, but was noted in
some specimens curving toward the vagina, though not passing into
it. A few sperm cells were present in the vas deferens, also in the
vagina and the seminal receptacle.

Female Reproductive Organs: The large ovary (Fig. 14, 0)
lies in the anterior third of the proglottid and extends transversely
across the segment. It has a length of 300u and a breadth of about
75 or 80p at its broadest point. It is irregular in shape, being com-
posed of a number of lobes. The end which is nearest the genital
pore is smaller than the other, allowing room for the mass of coils
of the vas deferens, the vagina, and the seminal receptacle. The
Ovary is concave on the dorsal surface and convex on the ventral.
On the dorsal surface of the end nearest the genital pore is located
the seminal receptacle and the vagina. The ova are large and very
distinctly shown in the ovary (Fig. 16). Posterior to the ovary is
the large yolk gland (Fig. 14, 16, y) which lies about the middle of
the proglottid. It is irregularly elongate in shape and extends
transversely across the segment, having a length of from 120 to
130, and a breadth of from 35 to 50u. Immediately in front of and
dorsal to the yolk gland and posterior to the ovary is the shell gland
(Fig. 14, sg) which is slightly ovoid in shape, 40 to 50u in diameter.
A small duct, the vitelline duct (Fig. 16, v), passes from the yolk
gland through the shell gland from which it receives a duct. The
combined ducts after passing through the shell gland unite with the
oviduct (Fig. 16, ov) which appears as a curved tube leading from
the ovary. These united tubes or ducts pass anteriad and slightly
ventrad into the uterus which develops as a blind tube in the region
of the ventral lobes of the ovary. This blind tube (Fig. 16, u)
grows in size and extends transversely across the segment. As it
becomes larger the tube forms pockets which extend anteriorly and
posteriorly and also dorsally, until it takes up the entire mass of
the proglottid between the excretory canals. In gravid segments
it even extends beyond the excretory canals. A small tube or duct,
which is really the end of the vagina, connects the seminal recep-
tacle with the yolk-shell gland duct and oviduct. This tube serves
to carry the sperm to the eggs in the oviduct for fertilization. The

MORPHOLOGY OF CESTODES FROM POULTRY 29

seminal receptacle (Fig. 16, sr) is a dilation of the vagina into an
oval shaped structure which is about 50% long and from 25 to 30u
in breadth at the widest part. From the seminal receptacle the
vagina passes laterad, lying posterior to the cirrus pouch, and unites
with the genital cloaca. The genital cloaca has its pore on the
lateral margin near the anterior end of the proglottid. The pore is
usually covered by the backward projection of the segment anterior
to it. The vas deferens and vagina pass between the dorsal and
ventral excretory canals and dorsal to the nerve tract. The vas
deferens is dorsal and anterior to the vagina.

In the mature segments the uterus becomes filled with ova and
it increases in size until it occupies the entire area between the
excretory canals, even extending beyond the canals in the gravid
proglottids. The uterus finally breaks up into compartments, each
containing a single embryo. The embryos (Fig. 7) are about 32
by 22 in diameter with onchospheric hooks 18 long. Usually
three membranes, but often four, enclose the embryo. The inner
membrane is thin and closely surrounds the embryo; the next is
heavy, being from 1.5 to 2u thick, composed of fibrous layers with
a few cells present. This layer is variable in thickness, depending
considerably upon the amount of contraction of the segment, as it
ranges in size from 40 to 32 to 50 by 36y, or it may be even
slightly larger. Usually one (Fig. 7) and sometimes two thin mem-
branes are found on the outside of the thick layer. These are
often wrinkled and bear at each end an appendage formed from
the outer membrane by which it is attached to the wall of the cap-
sule or compartment of the uterus.

In this species the oldest proglottids drop off from the worm
before they are fully mature. The embryos from the oldest seg-
ments on the worm do not show the characteristics of entirely ma-
ture ones, and there are distinct differences between them and those
that have been separated from the worm for some time. Single
proglottids that have separated from the worm are quite active and
remain in the intestine for some time before passing out with the
feces. Proof of this is furnished by the fact that a large number
of the free proglottids are found in the intestine at any time. Even
tho only a few worms are present in the intestine of a bird there is

30 JOHN E. GUTBERLET

usually a large number of free proglottids. If they did not remain
in the intestine for a considerable length of time there would not
be nearly as many. Further proof is furnished by the fact that the
free proglottids have embryos which are mature, showing the oncho-
spheric characteristics, while the oldest segments that are still at-
tached to the worm have embryos that are not entirely mature.
This same condition has been observed in Davainea proglottina as
Blanchard (1891:435) states that the oldest proglottids separate
from the others and remain in the intestine to become mature be-
fore passing out. The proglottids do not always separate from the
worm singly, but may drop off in groups of three or four.

The fact that the proglottids separate from the worm before
they are entirely mature is one of great importance in taking up
experimental work for infection of intermediate hosts. If the em-
bryos are fed to insects or other invertebrates before they are ma-
ture they will be digested, and thus infection cannot be produced.

B. CYSTICERCUS

The cysticercus of Choanotenia infundibuliformis was found
in the abdominal region of the body cavity in the common house
fly, Musca domestica. The flies had been fed on embryos from
ripe proglottids of this species of worm, and at the end of twelve
days were killed. The cysticerci appear to be nearly ripe or ready
for transmission into the adult host. The time for the develop-
ment of the cysticercoid varies with different species and under
different conditions. Grassi and Rovelli (1892:85) found that
Davainea proglottina developed from the onchosphere into a ripe
cysticercus in less than twenty days. Schmidt (1894:9) found that
the development of the cysticercoid of Drepanidotenia anatina
(Krabbe) varied with the time of the year and the influence of the
temperature. In the summer the embryo developed in an ostracod,
Cypris ovata, into ripe cysticercoids in two weeks.

The cyst proper (Figs. 11, 12, c) containing the scolex is oval
in shape, 220u long and 120, in diameter.

The bladder (Fig. 12, b) or tail, which is also oval in shape,
is located against one side of the cyst and is somewhat flattened on
that side. It is 220 to 230p long and from 116 to 120, in breadth.

MORPHOLOGY OF CESTODES FROM POULTRY 31

The scolex is 80 in breadth and 120, in length; neck is 40m in
diameter and 30 to 35 long; suckers are 55 to 60u in diameter.
The rostellum is 60 long and 20, in breadth, armed with a crown
of 18 hooks arranged in a single row. These hooks (Fig. 9) are
30 long with a long dorsal root and a short ventral root. The
suckers are lined with numerous minute hooklets or spines 1.5 to 2p
long which extend over the edges of the suckers and also over the
greater part of the surface of the scolex, including a part of the
neck region. Schmidt (1894: 16) described cuticular hooklets on
the suckers of Drepanidotemia anatina.

The size of the scolex may be somewhat variable as shown by
those in the cysticercoids of Drepanidotenia anatina by Schmidt
(1894: 10). In that species the intermediate host could be one of
two or more species of crustaceans and the size of the cysticercoid
varied with the size of the host in which it was parasitic.

The head of the rostellum is conical in shape, bearing a bluntly
pointed apex anterior to the end of the dorsal roots of the hooks
(Fig. 10, rv). This part of the rostellum is composed of minute
muscle fibers which are both circular and oblique. The rostellum is
slightly broader below the circle of hooks as it is an oval shaped
body.

The rostellar sac (Fig. 10, rs) is a deeply stained structure 10
to 12 thick. It extends from 10 below the hindermost part of
the rostellum to the anterior extremity of the scolex, forming an
oval shaped sac or sheath. It is composed of parenchymatous
tissue with large heavily stained oval or spindle shaped cells which
bear processes. The outer part of the sac is composed of a thin
layer of fine fibers which help to give it a definite shape. At the
lower edges of the sac the fibers are connected or associated to
some extent with similar fibers that form the inner layer of the
suckers. The anterior region of the rostellar sac, which forms
the sheath for the free head portions of the rostellum, is constructed
of an inner layer of fine fibers and an outer layer of large spindle-
shaped cells, the most of which bear fibrous processes at one or
both ends.

The suckers are composed of large spindle-shaped cells which
are arranged perpendicular to the edge. These are heavily stained

32 JOHN E. GUTBERLET

and form a compact layer. The inner boundary of the suckers
is composed of a layer of fibers which are both circular and oblique.
Some of these at the upper edges are associated with similar fibers
in connection with the rostellar sac.

The cyst is composed of two cell layers with an irregular
cavity between them. The cells are large and irregular in shape
with no special arrangement in the layer. Large intercellular
spaces lie between the cells, thus forming a loose network structure,
except at the base of the neck. At this point where the neck is
attached to the inner layer of the cyst the cells are smaller and
are in a compact mass. There is no definite boundary to the outer
part of the inner layer as well as to the inner part of the outer
layer of the cyst. Few cells with long connective processes extend
across the cavity from one layer to the other. This then forms
an irregular cavity (Fig. 11 ca) 2 to 20 in width between the two
layers of the cyst. This is the primitive cavity of Grassi and
Rovelli (1889: 373). The two layers of the cyst are formed
apparently by a fold which extends upward and inward from the
base of the neck, forming the gastrula cavity of Grassi and Rovelli
(1889: 402, g) and enclosing the scolex. This cavity varies in
width from 3 to 10 or 15p.

The bladder, an oval shaped structure, is located at one side
of the cyst and is attached to it at the posterior end by a narrow
connection (Fig. 12, cn). The posterior end of the cyst or the
region caudad of the base of the neck is somewhat drawn out
(Fig. 12). From this point is given off the attachment to the
bladder or tail portion of the cysticercoid. The fact that this
bladder is really a tail, even though it possesses a cavity, is shown
by the presence of the onchospheric hooks, which are located at
the end of the bladder opposite to that of the attachment of the
cyst (Fig. 12, oh).

The order of arrangement of the onchospheric hooks is indi-
vidual. In some specimens they are situated at the end of the
bladder, while in others they are at the side. In some the arrange-
ment is in a group, while in others they are in pairs. Some of
my specimens show a pair of embryonic hooks in the layers of

MORPHOLOGY OF CESTODES FROM POULTRY 39

the cyst between the base of the neck and the attachment of the
bladder, while the other two pairs of hooks are located in the
bladder.

The cavity of the bladder is formed apparently by a splitting
or hollowing out of the cells of the tail, because the wall is con-
tinuous and of the same histological structure. The wall of the
bladder is constructed of two layers, an inner cell layer and an
outer cuticular layer. The outer cuticular layer is more or less
striated on account of minute fibrils uniting it with the inner cell
layer. Histologically, the structure of the inner layer is con-
structed of somewhat granular substance arranged in fibers form-
ing a network which encloses clear spherical cells with large nuclei
(Fig. 13). Outside of the cuticular layer is located the peritoneum
of the host which lies upon the bladder and surrounds it as well
as the cyst.

C. COMPARISON OF ADULT AND CYSTICERCUS

A comparative study of the adult and the cysticercoid shows
the likeness which exists between them. The presence of the
same number of hooks, having exactly the same size and shape
as seen by comparing Figures 8 and 9. Minute hooklets of the
same size are present in both cysticercoid and adult lining the suck-
ers, the entire surface of the scolex and a part of the neck region.
Rosseter (1891: 365) shows that the hooks on the rostellum and
suckers of Echinocotylus Rosscteri undergo no changes during
the act of transition from cysticercus to adult stage. The rostellar
sac is of the same general shape in both. The head of the rostel-
lum is not expanded in the cysticercoid as in the adult because it
has not functioned as yet. This corresponds to figures as shown
by Schmidt (1894, Pl. VI, Fig. A) of the cysticercoid and Krabbe
(1869, Pl. VI, Fig. 114) of the adult of Drepanidotenia anatina,
and by Grassi and Rovelli (1892, Pl. IV, Fig. 7, 8) of the cysti-
cercoid and Blanchard (1891: 16) of the scolex of Davainea
proglottina. No measurements are given for the rostellum of
either the cysticercoid or the adult by the above authors.

There is a great deal of difference in the size of the scolex
between the cysticercoid and the adult. In my specimens the

34 JOHN E. GUTBERLET

scolex of the adult is between four and five times as large as that
of the cysticercoid. The scolex of the cysticercoid has as yet
not functioned so that the musculature of the organs is not devel-
oped as in the adult, consequently is not nearly as massive. The
cells also are smaller than those of the adult.

Schmidt (1894: 10, 44) shows that the adult scolex of Dre-
panidotenia anatina is about three times as large as that of the
cysticercoid. He also states that the size of the cysticercoid may
vary with the size of its host.

Different forms become modified in changing from the inter-
mediate to the adult hosts as shown by Schmidt (1894) in Dre-
panidotenia anatina, Rosseter (1891) in Echinocotylus Rossetert,
and Grassi and Rovelli (1892) in Davainea proglottina.

Onchospheric hooks in the wall of the tail are the same size
(18) and shape as those of the embryos found in the mature
proglottids.

A consideration of these factors of morphological significance
which demonstrate the resemblances between the cysticercoid and
adult, indicates clearly that this cysticercoid is the intermediate
stage of Choanotenta infundibuliformis.

OTHER CHICKEN CESTODES IN THE UNITED STATES

1. Davainea tetragona (Molin 1858) Blanchard 1891

Diagnosis: Length 10 to 250 mm. by 1 to 2.5 mm. in breadth,
varying with state of contraction. Scolex (Fig. 19) 175 to 215p
in diameter, with retractile rostellum 25 to 50u in diameter, armed
with single row of about 100 hooks. Rostellar hooks (Fig. 20)
6 to 9n long through longest axis, hammer-shaped, with long ven-
tral root and short dorsal root, prong short and recurved. Suckers
oval, 60 to 110 in diameter, armed with 8 to 10 rows of small
hooks of various sizes. Acetabular hooks (Fig. 21) range in
size from 4 to 8 through longest axis, having thorn-like
prong, short dorsal root, and longer flattened ventral root, which
is shorter than prong. Neck long and slender, but often as broad
as head. Segments trapezoidal and imbricate, edges of strobila
serrate. Oldest segments usually longer than broad, often bell-

MORPHOLOGY OF CESTODES FROM POULTRY 35

shaped. Genital pores usually unilateral, situated one in each
segment, at or in front of middle of lateral margin, frequently
marked off by papilla. Male and female canals pass on dorsal
side of nerve and excretory vessels.

Male Reproductive Organs: Testes 20 to 30 in median field
surrounding female organs, most of them lying on aporose side
of latter. Vas deferens situated in anterior third of segment,
beginning near median line, and extending in much convoluted
course laterally to base of cirrus pouch which it enters and, after
a few coils in basal portion of latter, passes into cirrus. Cirrus
pouch pyriform, 75 to 100 in length. Basal portion surrounded
by prominent layer of longitudinal muscle fibers, neck with thick
layer of transverse fibers. Cirrus without apparent spines.

Female Reproductive Organs: Ovary in middle of segment.
Yolk gland posterior to ovary, irregularly reniform, slightly longer
in its transverse axis, about 100, in diameter. Shell gland promi-
nent, 504 in diameter, immediately in front of yolk gland. Vagina
begins at genital pore, posterior to opening of cirrus pouch, at
first very slender but at distance of 15 to 25u from genital pore
swells out into thick-walled tube, functioning as seminal recep-
tacle. This extends transversely across segment and joins oviduct
on dorsal side of ovary near median line. Oviduct, after being
joined in shell gland by vitelline duct, proceeds forward and ends
on dorsal side of ovary. Definite and persistent uterus not devel-
oped. Eggs pass from distal end of oviduct, become imbedded
in fibrous and granular or gelatinous mass which fills up most of
segment. This mass divides into 50 to 100 portions to form egg
capsules, each surrounded by membrane and containing 6 to 12
or more eggs. Egg is surrounded by three envelopes,—inner, close
to onchosphere, often scarcely visible; middle layer or envelope
much folded, giving appearance of network between inner and
outer membranes; and smooth outer envelope. The onchosphere
measures 10 to 15u in diameter; the outer envelope measures from
25 to 50u in diameter.

One point noted here that has not been mentioned before by
other authors is that the genital pores are irregularly alternate.

36 JOHN E. GUTBERLET

They are usually unilateral. The existence of this irregularly
alternate occurrence of the genital pores may be an anomaly, but
it is rather frequent for such a condition.

2. Davainea echinobothrida (Megnin 1880) Blanchard 1891

Diagnosis: Length up to 250mm; width 1 to 4 mm. Head
(Fig. 22) 0.25 to 0.45 mm. in diameter, with retractile rostellum
100 to 150n in diameter, armed with crown of about 200 hooks
arranged in two rows. Suckers round or oval, 90 to 200 in diam-
eter, armed with 8 to 10 rows of hooks. Rostellar hooks (Fig.
23) similar to those of Davainea tetragona, but larger, measuring
10 to 13p in length. Acetabular hooks (Fig. 24) likewise similar
to those of D. tetragona, but also larger; size variable, smallest
being 7 or 8» in length and largest measuring from 14 to 16n.
Neck thicker and generally shorter than D. tetragona, nearly equal
to width of head. Strobila resembling that of D. tetragona, but
serrate border more pronounced. Oldest segments in preserved
specimens also differ from those of D. tetragona, being less elon-
gate and frequently marked by median constriction. Owing to
this constriction adjacent borders of most posterior segments pull
apart in median line and remain joined only at sides, giving rise
to median series of openings through posterior portion of strobila.
Genital pores irregularly alternate, or sometimes almost entirely
unilateral, situated one in each segment posterior’ to middle of
lateral margin. Male and female canals pass on dorsal side of
nerve and excretory vessels.

Male Reproductive Organs: Testes 20 to 30, arranged in
median field surrounding female glands as in D. tetragona. Vas
deferens lies in anterior third of segment much as in D. tetragona.
Cirrus pouch flask-shaped, 130 to 180» in length. Basal portion
globular or ovoid, surrounded by layer, about 10p thick, of longi-
tudinal muscle fibers inside of which is a layer about 12p thick
of transverse fibers. Neck of pouch measures 50u to 75 in length
by 15 to 20» in diameter, surrounded by layer of transverse fibers
thickened at distal end to form sphincter. According to Mégnin,
the cirrus is armed with minute spines.

Female Reproductive Organs: Female organs same as in
Davainea tetragona, and onchospheres (Fig. 25) are also similar

MORPHOLOGY OF CESTODES FROM POULTRY 37.

in structure and size, 14 to 15y in diameter. Onchospheric hocks
6 to 7p long. Egg capsules in groups of 6 to 12 or more, em-
bedded in a fibrous gelatinous mass.

In the living specimens very little difference can be noticed
except in size of the species D. tetragona and D. echinobothrida.
They are both quite transparent and appear much alike in every
respect in external appearance, except that D. tetragona is slightly
more transparent, while the oldest segments of D. echinobothrida
have very distinct median constrictions between them, appearing
almost as a series of openings.

The chief differences between D. tetragona and D. echinoboth-
vida are that in the latter the animal is larger, the hooks are more
numerous and larger, and the structure and size of the cirrus
pouches show a very distinct difference. There is also a difference
in the pathological effect of these spiny-suckered forms. D. echino-
bothrida produces large nodules or ulcers in the intestinal
wall. The scolex bores through the mucosa of the intestine and
in some cases nearly through the muscular coats. This disease
in fowls is termed “nodular tzeniasis”, as described by Moore
(1895: 1), and is often mistaken for other diseases.

3. Davainea cesticillus (Molin 1858) Blanchard 1891

Diagnosis: Length 10 to 125 mm. Maximum width 1.5 to
3 mm. Head cylindrical (Fig. 28), sometimes spheriodal, 0.3 to
0.6 mm. wide and 0.2 to 0.4 mm. long. Suckers unarmed, about
100, in diameter. Rostellum broad and flat or hemispherical, 0.25
to 0.35 mm. wide, armed with a crown of 200 to 300 hooks which
are very unstable and easily lost, arranged in two ranks. Hooks
(Fig. 29) 8 to 12» long with short dorsal root and long ventral
root. Neck very short. Anterior segments three to five times
as broad as long; the following increase in size until they become
equal in length and breadth and finally even longer than broad;
borders overlapping. Genital pores irregularly alternate, one in
each segment, somewhat in front of middle of lateral margin in
young segments and nearer the middle in older segments. Vagina
and cirrus pouch pass dorsal of the two excretory canals and
nerve.

38 JOHN E. GUTBERLET

Male Reproductive Organs: Testes (Fig. 17, t) 20 to 30 in
number in posterior portion of segment. Vas deferens much
coiled before entering base of cirrus pouch, also coiled within latter.
Cirrus pouch ellipsoidal, 120 to 1504 long by 55 to 7Op wide.
Cirrus when protracted 10y in diameter, armed with minute spines,
and with bulbous enlargement 20u in diameter at its base, where
it becomes continuous with cirrus pouch.

Female Reproductive Organs: Vagina enlarged before reach-
ing median line into small seminal receptacle (Fig. 17, sr). Ovary
occupies middle field in front of testes. Yolk gland and_ shell
gland posterior to ovary, ventral and dorsal, respectively, in rela-
tive position. Uterus at first in front of ovary as cord of cells;
gradually increasing in size, finally occupies most of segment and
frequently extends laterally beyond excretory canals. In oldest
proglottids it becomes divided into compartments, or capsules,
each containing a single egg. Embryo (Fig. 30) 36 by 27 in
diameter, with very thin membrane closely adherent to surface.
Embryo further enveloped by thicker, smooth fibrous membrane,
oval in shape, 45 to 40u in diameter, with filament at each pole
attaching to thin outer wrinkled membrane about 35 by 50z in diam-
eter: finally egg is surrounded by capsule composed of outer and
inner membrane, latter closely adherent to or fused with outer
egg membrane; and former more or less widely separated from
latter and connected with it by number of septa.

One of the principal points noted here that is not mentioned
by other authors is the size of the rostellar hooks. In my speci-
mens they seem to be somewhat larger than those described by
others. They have been described as being 8 to 10u long, while
my forms show many of them to be distinctly 12y in length. A
second point noted here is the method of the development of the
uterus. The uterus develops in front of the ovary. It first ap-
pears as a solid cord of cells connected with the united ducts of
the ovary, shell gland, and yolk gland. The solid cord of cells
which later gives rise to the uterus becomes hollow and appears
as a blind sac or tube. This then grows in size, forming pockets,
and finally fills up the entire proglottid.

MORPHOLOGY OF CESTODES FROM POULTRY 39

This form is one of the most common chicken tapeworms
and is the most easily recognized. It can be identified by the head
with its broad, flat rostellum which shows up very prominently ;
the width of the most anterior segments is usually equal to or
greater than the width of the head, and the eggs are distributed
in individual egg capsules in mature proglottids.

4. Hymenolepis carioca (Magalhaes 1898) Ransom 1902

Diagnosis: Length 30 to 80mm. Breadth at neck 75 to 150p,
at posterior end 0.5 to 0.7 mm. Segments three to five times or
more broader than long throughout strobila. Head (Fig. 26)
flattened dorso-ventrally, 140 to 160 long, 150 to 215 wide and
100 to 140» thick. Suckers shallow, 70 to 904 in diameter, un-
armed. Rostellum unarmed; in retracted position 25 to 40 in
diameter and 90 to 100 in length, with small pocket opening to
exterior in anterior position. Unsegmented neck portion of strobila
0.6 to 1.5 mm. long. Genital pores almost entirely unilateral, a
single pore being located in each segment slightly in front of middle
of right-hand margin.

Male Reproductive Organs: Testicles three in number, nor-
mally two on left and one on right of median line. On dorsal
side of inner end of cirrus pouch vas deferens is swollen into
prominent seminal vesicle (Fig. 18, sv) which may attain a size
of 70 by 50y. Cirrus pouch (Fig. 18, cp) in sexually mature
segments 120 to 175 long by 15 to 18, in diameter ; almost cylindri-
cal, slightly curved toward ventral surface of segment; on outer
surface about 20 longitudinal muscle bands, 2 to 3 in thickness,
very prominent in cross section; vas deferens enlarged within
cirrus pouch to form small seminal reservoir occupying proximal
two-thirds of pouch; distal third of portion of vas deferens within
pouch very slender, about 1u in diameter and functions as cirrus.
Genital cloaca 12 to 36 deep.

Female Reproductive Organs: Opening of vagina in floor of
genital cloaca, ventral and posterior to cirrus opening. First por-
tion of vagina very narrow, lp in diameter. Small vaginal sphinc-
ter 8 to 10u from vaginal opening. On inner side of sphincter
vagina gradually increases in diameter, and in sexually mature

40 JOHN E. GUTBERLET

segments swollen into prominent seminal receptacle (Fig. 18, sr)
which extends forward to anterior border of segment and inward
considerable distance beyond proximal end of cirrus pouch. Ovary
faintly bilobed or trilobed in posterior half of proglottid. Yolk
gland spherical or ovoid, 30 to 40y in diameter, situated near median
line of segment, posterior and dorsal of ovary. Uterus at first
solid cord of cells extending transversely across segment along
anterior border of ovary; becomes hollowed out and grows back-
ward on dorsal side of ovary; in gravid segments occupies nearly
entire segment and filled with eggs. Eggs (Fig. 27) in gravid
uterus spherical or oval, with four thin membranes, the two middle
membranes often approximate to form thick layer which shows
somewhat of a cellular or coarse granular structure. Diameter of
outer membrane 36 by 36 to 75 by 70Opu, of outer middle mem-
brane 30 by 30u to 65 by 60yn, of inner middle membrane 26 by
26 to 40 by 35p, of inner membrane 24 by 16 to 29 by 21p. This
membrane often lies so close to onchosphere that it can scarcely
be distinguished from edge of embryo. Onchosphere is 18 by 14
to 27 by 19u in diameter; length of embryonal hooks 10 to 12n.

This form is thread-like and usually occurs in great numbers.
It is very delicate and fragile and can be recognized by that fact
alone, as it is the most fragile of the chicken forms known.

SUMMARY

1. By morphological comparison of the cysticercoids produced
experimentally in flies and adult of Choanateenia infundibuliformis
they are shown to be identical.

2. Morphological points noted are the presence of minute
hooklets on the suckers and entire surface of scolex in Choanatenia
infundibuliformis. The manner of development of uterus in the
same species is by means of a blind tube which grows in size,
forming pockets, and later breaks up into small compartments.
In Davainea tetragona the genital pores were found to occur irreg-
ularly alternate in the proglottids. The hooks on the rostellum
of Davainea cesticillus were found to vary in length from 8 to
12. The uterus in development first appears as a solid cord of
cells which becomes hollow and in growing forms pockets, filling
the entire proglottid.

MORPHOLOGY OF CESTODES FROM POULTRY 41

BIBLIOGRAPHY
BLANCHARD, R.
1891. Notices helminthologiques. Sur les téniadés a ventouses armées.
Mem. soc. zool. France., 4: 420-489.
DAVAINE, C.
1877. Traité des entozoaires et des maladies vermineuses de l'homme et
des animaux domestiques. Paris. Ed. 2, 1003 p.
GrassI, B., and Rovetut, G.

1888. Bandwiirmer Entwickelung. I. Centralbl. Bakt. und Parasitenk.,
Salsa:

1889. Embryologische Forschungen an Cestoden. Centralbl. Bakt. und
Parasitenk., 5: 370-377; 401-410.

1892. Ricerche embriologiche sui Cestodi. Atti. Accad. Gioenia Sci.
Nat. in Catania, 4: 1-108.
GUTBERLET, J. E.

1916. Studies on the Transmission and Prevention of Cestode Infection
in Chickens. (In Press.)

Hassat., A.
1896. Bibliography of Tapeworms of Poultry. Bull. Bur. An. Ind., 12:
81-88.
Krasse, H.
1869. Bidrag til Kundskat om Fuglenes Baendelorme. Vid Selsk. Skr.
v. Roekke. Nat. og Math., 8: 251-368.
MaGAa.uHaes, P. S. DE
1898. Notes d’helminthologie Brésilienne. Arch. Parasit., 1: 442-451.

Mottin, R.

1858. Prospectus helminthum, quae in prodromo faunae helminthologicas
Venetiae continentur. Sitzber.k. Akad. Wiss. Wien, math. naturw.

kl, 30: 127-158.
Moore, V. A.
1895. A Nodular Taeniasis in Fowls. Bur. An. Ind. Cir. 3; 4 pp.
MRAZEK, AL.

1907. Cestoden Studien. I. Cysticercoiden aus Lumbriculus variegatus.
Zool. Jahrb., Syst., 24: 591-624.

Prana, G. P.

1882. Di una nuova specie di Tenia del gallo domestico (Taenie bothri-
oplitis) e di un nuova cisticerco delle lumachelle terrestri (Cysti-
cercus bothrioplitis). Mem. Accad. Sci. Inst. Bologna, 2: 387-394.

42 JOHN E. GUTBERLET

Ransom, B. H.

1900. A new Avian Cestode-Metroliasthes lucida. Trans. Amer. Micr.
Soc., 21: 213-226.

1902. On Hymenolepis carioca (Magalhaes) and H. megalope (Nitzsch)
with Remarks on the Classification of the Group. Trans. Amer.
Micr. Soc., 23: 151-172.

1904. The Tapeworms of American Chickens and Turkeys. Ann. Report
Bur. An. Ind., 21: 268-285.

1904a. Manson’s Eye-worm of Chickens (Oxyspirura Mansoni). Spiny-
Suckered Tapeworms of Chickens. Bull. Bur. An. Ind., 60; 72 pp.

1909. The Taenoid Cestodes of North American Birds. Bull. U. S. Nat.

Mus., 69: 1-141.
1911. A New Cestode from an African Bustard. Proc. U. S. Nat. Mus.,
40: 637-647.
Rosseter, T. B.
1890. Cysticercoids parasitic in Cypris cinerea. Jour. Micr. Nat. Sci., 9:
241-247.

1891. Sur un cysticercoide des Ostracodes, capable de se developper dans
lintestin du canard. Bull. soc. zool. France, 16: 224-229,

1892. On a New Cysticercus and a New Tapeworm. Journ. Queckett
Micr. Club, 4: 361-366.

1897. On Experimental Infection of Ducks with Cysticercus coronula
Mrazek (Rosseter), Cysticercus gracilis (von Linstow), Cysti-
cercus tenuirostris (Hamann). Journ. Queckett Micr. Club, 6:
397-405.

ScHMi0T, J. E.
1894. Die Entwicklungsgeschichte und der anatomische Bau der Taenia
anatina (Krabbe). Arch. Naturg., 1: 65-112.
STILEs, C. W. ;
1896. Report upon the Present Knowledge of the Tapeworms of Poultry.
Bull. Bur. An. Ind., 12; 78 pp.
Tower, W. L.

1900. The Nervous System of the Cestode Monezia Expansa. Zool.
Jahrb. Anat., 13: 359-384.

MORPHOLOGY OF CESTODES FROM POULTRY 43

EXPLANATION OF PLATES

Unless otherwise stated all drawing were made with the aid of a camera

lucida,
ABBREVIATIONS
b—bladder rs—rostellar sac
c—cyst sg—shell gland
ca—primitive cavity sr—seminal receptacle
cn—connection of bladder with cyst sv—seminal vesicle
cp—cirrus pouch t—testes
dex—dorsal excretory canal u—uterus
ex—excretory ring in scolex v—vitelline duct
o—ovary va—vagina
oh—onchospheric hooks vd—vas deferens
ov—oviduct vex—ventral excretory canal
r—rostellum y—yolk gland
PLATE V
CHOANOTAENIA INFUNDIBULIFORMIS
Fig. 1. Scolex much contracted. x40
Fig. 2. Scolex normal extension. x145
Fig. 3. Longitudinal section of scolex, showing rostellum and rostellar sac.
x425
Fig. 4. Section of portion of sucker, showing hooklets. x425
Fig. 5. Section of portion of wall of scolex, showing hooklets. x425
Fig. 6. Longitudinal nerve tract, showing nerve cells with processes. x650
PiaTE VI
Fig. 7. A, B, C, D. Embryos from mature proglottid. x425
Fig. 8. Hooks from rostellum of adult. x425
CYSTICERCUS OF CHOANOTAENIA INFUNDIBULIFORMIS
Fig. 9. Hooks from rostellum of cysticercus. x425
Fig. 10. Section through scolex, showing rostellum with hooks and rostellar
sac. x425
Fig. 11. Section through scolex and cyst, showing suckers with hooklets,
structure of cyst and primitive cavity between layers of cyst. x425
Fig. 12. Reconstruction of cysticercus with cyst and bladder or tail, showing
scolex in cyst and onchospheric hooks in bladder. x145
Fig. 13. Section of wall of bladder, showing histological structure and

peritoneum of host. x425

Fig.

Fig.

Fig.

Fig.

Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.

Fig.
Fig.

Fig.

Fig.
Fig.

mu §

15.

16.

17.

18.

19.
20.
ra
22)
23.
24.
25,

26.
27,

28.

29.
30.

JOHN E. GUTBERLET

Pirate VII

Choanotaenia infundibuliformis. Reconstruction of mature pro-
glottid, showing reproductive organs, excretory vessels, and nerve.
x145

C. infundibuliformis. Reconstruction of cirrus pouch showing
cirrus and vas deferens, also part of vagina in connection with
cloaca. x310

C. infundibuliformis. Reconstruction of female reproductive or-
gans, showing part of ovary, yolk gland, shell gland, oviduct,
vitelline duct, uterus, and connection of ducts with uterus and
seminal receptacle. x310

Davainea cesticillus. Reconstruction of mature proglottid, showing
reproductive organs and excretory vessels.. x145

Hymenolepis carioca. Reconstruction of mature proglottids, show-
ing reproductive organs from ventral view. x145

Pirate VIII

Scolex of Davainea tetragona. x145

Hooks from rostellum of D. tetragona. x425

Hooks from suckers of D. tetragona. x425

Scolex of Davainea echinobothrida. x145

Hooks from rostellum of D. echinobothrida. x425

Hooks from suckers of D. echinobothrida. x425

Embryos of D. echinobothrida, showing capsule and fibrous gel-
atinous mass in which it is embedded. x425

Scolex of Hymenolepis carioca, after Ransom.

A, B, C, D. Embryos of Hymenolepis carioca, showing enveloping
membranes. x425

Scolex of Davainea cesticillus. Free-hand drawing of living spec-
imen well extended, showing rostellum.

Hooks from rostellum of D. cesticillus. x425

A, B, C, D. Embryos of D. cesticillus, showing enveloping meni-
branes. x425

ave a Ea:
= a Bd.

a

AD

Vd

~ALA

PLATE VII

Piate VIII

ah
rea. i ve
Rail Nay Hf

CAN ay BY
AN ‘
Cv

WA
=a)

Contributions from the Zoological Laboratory of the University of [linois,

under the Direction of Henry B. Ward, No. 62.

STUDIES ON THE TRANSMISSION AND PREVENTION
OF CESTODE INFECTION IN CHICKENS

} JoHN E. GuTsBervet, Carroll College, Waukesha, Wis.

Intropuction. The problem of tapeworm infection in chickens
has received but little attention in the United States. In fact it
was entirely untouched until a few years ago when the subject was
opened by Stiles (1896) and work was begun by Ransom (1900,
1902, 1904, 1909) on poultry and other birds. At the present time
less than a dozen references constitutes the entire American lit-
erature on the subject. Five species of cestodes are known to in-
fest chickens in various parts of the United States.

No work has been done on the life history of the forms
existing in this country. However, studies have been carried
on extensively with poultry cestodes in various other parts of the
world, though as yet very little has been finally determined. In
only one species of chicken cestode has the life cycle been demon-
strated experimentally. That is Davainea proglottina (Davaine)
for which Grassi and Rovelli (1889: 372; 1892: 30, 85) have shown
that the intermediate host is a slug (Limax cinereus). This species
of cestode has not as yet been reported in this country.

Chickens are supposed to become infested with another species
through eating snails, a third through eating flies, and a fourth
through eating earthworms. Piana (1881-1882) found in a snail
(Helix) two eysticercoids which agree closely with the head of
Davainea tetragona (Molin). No experiments were performed to
demonstrate that the cysticercoid was the larval stage of that
species and the only evidence of their connection is the similarity
in form. Grassi and Rovelli (1892: 33, 87) found in flies cysticer-
coids which closely resembled Choanotaenia infundibuliformis and
base their conclusion of identity on the structural similarity.

Grassi and Rovelli (1889: 372; 1892: 29) found in earthworms
(Allolbophora foetida) eysticercoids which they associated with the
scolex of Dicranotaenia sphenoides, a chicken cestode not reported
in this country. Here again the only evidence for regarding it to
be the larval stage of this species is a general structural likeness.
In no one of these three forms was the life eycle demonstrated ex-
perimentally. Such comparisons are not proof that the cysticer-
coids are intermediate stages of definite species, but only give a
clue as to the probable life cycle,

CESTODE INFECTION IN CHICKENS 219

In other kinds of poultry more has been done on the life his-
tories of their cestodes. The life cycles of five species of duck
cestodes have been demonstrated through experiment. Schmidt
(1894) proved that Drepanidotaenia anatina (Krabbe) has its in-
termediate stage in a fresh-water crustacean (Cypris ovata). He
fed large quantities of tapeworm eggs to the crustaceans and found
that the larvae developed in two weeks during the summer. Ros-
seter (1891, 1892) has shown that a second duck cestode, Echimo-
cotylus Rosseteri (Blanchard), has its intermediate stage in an-
other small fresh-water crustacean (Cypris cinereus). He fed large
numbers of the crustaceans to ducks which upon examination later
yielded a large crop of tapeworms of the species named.

Rosseter (1897) also demonstrated experimentally the life his-
tories of three other species of duck cestodes. He had discovered
some cysticerci in crustaceans which he compared with the adult
worms occurring in ducks and found that they agreed closely. He
produced Dicranotaenia coronula in a duck by feeding it Cypris
cinerea. Drepanidotaenia gracilis was introduced into the ducks
through Cypris cinerea and Cypris viriens: Drepanidotaena
tenwirostris was likewise raised by feeding Cyclops agilis.

As in other cases the question of control of infection in chickens
depends to a great extent upon the life history of the parasites.
Little can be done to wipe out the disease until more is known of
its source. Certain methods may be employed to check it, but as
yet it has been impossible to prove the exact source of infection.
Usually it is easiest to control such forms during the developmental
stages.

This paper is the result of some. investigations carried on to
find out the life history of certain chicken tapeworms. Numerous
experiments were tried on various insects and many observations
made on the habits of the birds in the endeavor to ascertain where
the cause of the infection was located. The habits of the birds are
probably the chief factors to be dealt with in experiments of this
kind. Certain insects that are common about the habitats of the
birds are readily eaten. They are hence more likely to be inter-
mediate hosts than those which are rare in these localities. Such
factors have been taken into consideration and through experiment
it has been shown that one cestode, Choanotaenia infundibuli- —
formis, has its intermediate stage in the common house-fly.

The most of the material was collected, and the experimental

220 JOHN E. GUTBERLET

ee eee ee

work was done on a farm at Hardy, Nebraska. A large amount of
material was also collected at the poultry farm at the University
of Illinois.

Thanks are due to Professor D. O. Barto, of the University
of Illinois, for giving me the privilege of collecting material at
the poultry farm. For other assistance I am indebted to my father
and mother, William and Flora Gutberlet, for their untiring efforts
to make this work a success by taking records and making collec-
tions of material at times of the year when they would not otherwise
have been taken.

I wish to express my appreciation to Dr. Henry B. Ward, at
whose suggestion this work was first taken up, for his helpful sug-
gestions and criticisms during the preparation of this paper.

Mernops or Tecunic. In making collections of tapeworms
the intestine of the bird was slit open under water and the con-
tents removed by shaking gently. The worms are usually attached
to the wall and can be easily seen and removed with the aid of a
pair of needles. Those that are not attached sink to the bottom of
the dish.

In removing the worms from the intestine it was found best
to transfer them directly to fresh water. A weak saline solution
was demonstrated to be harmful as the worms die in it in a very
short time. Tower (1900: 362) found saline solution harmful to
cattle cestodes (Monezia). In fresh water, the worms soon become
well extended and remain alive and normal for twelve to fifteen
hours, or even longer. The worms are best killed in a corrosive-
acetic solution and preserved in 70% alcohol and glycerine. For
study of structure and accurate diagnosis of species the worms
were cut in sections from 5 to 10 microns in thickness, stained in
Delafield’s or Ehrlich’s acid haematoxylin and destained in acid
alcohol.

In order to use house-flies for experimental purposes one has
to work out first, methods of keeping them alive. The flies used
were kept for experiment in small cages. They demanded a great
deal of attention because the slightest disturbance of conditions
was harmful. They were fed most satisfactorily on blood, liver,
and spleen. It was found that a fly could not live long without-
a constant supply of water in the cages. The cages had also to be
placed in the sun for a few minutes each morning, and then kept
in the shade for the rest of the day, but not in a cool place,

CESTODE INFECTION IN CHICKENS 221

At the conclusion of the experiment the flies were killed, fixed in
corrosive-acetic solution and preserved in 70% alcohol. The chitin
covering of the body of the flies was punctured to allow these
fluids to penetrate properly.

Large bottles proved very satisfactory as cages for beetles
during the experiments. The bottles were fitted with glass or
metal stoppers provided with pores for the passage of air. Leaves
and a small amount of soil were placed in the bottom of the bottle.
The beetles were killed and preserved like the flies, but before
sectioning the chitin covering was removed by dissection.

Amount or Infection. The flock of chickens upon which
these studies were carried on was so heavily infected with the tape-
worm disease during certain seasons that it was rather unusual to
find a bird that did not harbor at least a few of the parasites. The
investigations extended over a period of two summers. Close ob-
servations were made during those seasons, and also at several
other times during the year, to secure a record of the amount of
infection during other seasons than the summer months.

The first summer (1912) about fifty chickens were examined
for parasites. Eight of these were adults and in no case was there
any infection. Ten young birds from six weeks to two months old
were examined in June, but none of them were infected. Lhe first in-
fection of tapeworms for that year was detected on July25. Between
that date and September 9, thirty-two young birds were examined
and every one showed some infection. In some it was slight, while
in others it was very heavy. During this same period, between
July 25 and September 9, some adult birds were examined but
yielded no parasites.

During the summer of 1913 forty birds were examined between
August 10 and September 18, with some infection in every bird.
A few of these were adult birds which had only a few parasites.
The young birds were more heavily infected, although the number
of parasites varied with different birds. In one bird which was ex-
amined at the age of seven weeks, twenty-five tapeworms were
found. Between June 17 and August 1, eight birds were examined
and cestodes were present in every bird with the exception of one
adult killed on June 24.

I have records of infection in the flock for January 1 and
April 27, 1918, and for November 20, December 2, and December
26, 1913. There are five species of worms infesting the chickens
in this place and further details are given in the table.

222 JOHN E. GUTBERLET

Between June 20 and August 1, 1913, examinations were made
of about fifteen birds at Urbana, Ill. Some of these were from
the poultry farm at the University of Illinois and others were from
private yards of residents in this vicinity; in only one bird was
there any trace of an infection. In that case there were a few
fragments of worms which were in such a state of disintegration
that they could not be preserved or determined. No further ex-
aminations for parasites were made in this locality until December
2, 1913, when it was discovered that the chickens at the poultry
farm at the University of Illinois were badly infested. Several
were examined and found to harbor Davainea echinobothrida,
Davainea cesticillus, and Hymenolepsis carioca.

A general examination was made of the living birds at the
poultry farm and it was discovered that symptoms of cestode dis-
ease were manifested by the great majority of the chickens, al-
though the infection was apparently not heavy except in a small
percentage of the flock.

In making examinations upon dead birds infested eit Dava-
inea echinobothrida it was found that large nodules were formed
in the intestinal wall which is a characteristic pathologic effect
of this particular spiny-suckered form. Davainea cesticillus seems
to be almost universally present as there was hardly an infested
bird examined in Nebraska or Illinois that did not harbor some of —
this species.

The following table shows the amount of infection and the
number of worms occurring in each bird examined, both in Ne-
braska and Illinois:

No. of No. of No. of No. of No. of Ch.

DATE LOCALITY Age of D. cesti- 0D. tetra- 0D. echino- Hymeno. infundibu-
host cillus gona bothrida —_carioca liformis
July 25,1912 Hardy, Neb. 4 mo. 5
a 29 mG 4 mo, 2 8
August 2 me 5 mo. 3
Ow a os 5 mo. 3) 1 20 2
fe 8 Ga 5 mo. 10 25 10
Lt 9 Be Oemo: 10 So
ae 10 Ge 5 mo. 5 15 5 2
BY ith Ot 5 mo 7 10 3
Bie 12 Bis 5 mo. 10 10 30 3
4! 15 he Sm: 5 4 il
4 20 ais Adult
cis 20 a 5 mo. 3 15 3 at
oie 21 OIG 5 mo. 15 10
oe 21 BY 5 mo, 3 2 2
ue 22 eit 5 mo. 3 8 3

CESTODE INFECTION IN CHICKENS i 223

No. of No. of No. of No. of No. of Ch.

DATE LOCALITY Age of D. cest- 0D. tetra- 0D. echino- Hymeno. infundibu-
Host cillus gona bothrida carioca _liformis
us 23 ae 5 mo. 3 3 2 2
af 25 Gt 5 mo. 5 10 10
ag 27 cig 5 mo 6 4 5
“ 29 OL Adult
September 2 ot Adult
ee +L OG 6 mo. 5 2 10
ee 6 aS 6 mo. 15 10 6
by 7 Hardy 6 mo.; 10 14 5
ie 8 at 6 mo. 4. 10 2
se 9 AG 6 mo. 10 10 5
January 2, 1913 hi Adult 3 5
March 23 a Adult
ee 25 ot Adult
a 30 BC Adult
April 27 a Adult 10
June 17 ee Adult
OG 24 Ce Adult
oe 21 Urbana 2 yr.
os 23 ae 2 yr.
cc 28 a 2 yr.
July 7, 17, 20 24 Hardy 4 mo. infection, but records incomplete.
August 10 a 4 mo. 5 10 15
as ial ce 4 mo. 3
ui 15 ce 4 mo. 3
oe 16 ee 5 mo. 155 30 20 10
6 ily OG 5 mo 25 30 5 8
BG 19 GG 5 mo 6 15 5
oe 20 GC 5 mo 6 6
Ge 26 ts 5 mo 15 2
oe 26 OG 5 mo 20 25 8 10
Bu 27 «se 5 mo. il 5 4
as 28 a6 5 mo. 2 10 10 5
us 28 EG 5 mo. 10 10 6
os 30 Hardy 5 mo. 8 18 3
September 2 OG Adult 3 12 4
Be 4. a 5 mo. 20 20
GG 6 ots 7 wks. 17 8
at 10 oe 5 mo. 8 10 5
cae 10 Gt 5 mo 15 25 4
OE 11 ae 5 mo 10 15 4
Gb 12 On: 5 mo 25 35 15
ee 13 “6 5 mo 8 10 4 8
ce 15 ae 6 mo 10 10 5
aU 16 Gi 6 mo 3 30
OG ity ae 6 mo. 20 10
ce 20 oe 8 mo. 35 6 10
December 2 Urbana 4. mo. 20 30
fe 5 6 4 mo. 3
ae 6 a Adult 5 5
GG 9 26 6 mo. 6 6
ie 24 Knoxville, Ill Adult Alte 00 00 00 1
Jb 26 Hardy Adult 1 11 3
January 1, 1914 ue Adult 3 2 5

224 JOHN E. GUTBERLET

Symproms AND Errecrs of TAPpEworM INFECTION. A great
deal has been written on the symptoms of this disease by various
authors, but in every case they were unable to reach any definite
conclusions on the subject. In my own study, which was exten-
sive, I reached the following definite conclusions: The symptoms,
‘while not really individual, vary to some extent with the different
birds, with the age of the birds, and with the degree of infection.
Some birds are affected by the disease much more than others and
show symptoms and effects much more readily. Some birds that
show no symptoms and appear in good health are heavily infested
with the worms, while others showing severe effects and manifesting
all the symptoms are not nearly as heavily infested. The age of the
host is a factor of much importance for indicating the presence of
an infection with the species I studied. Young, growing birds are
affected much more than adults and show the symptoms more dis-
tinetly. Even a comparatively slight infection can be detected in
a young bird a few weeks of age, while a heavy infection is very
marked. Most adults manifest no external symptoms as far as
appearance is concerned unless they are heavily infested. The de-
gree of infection is another factor which is of importance in
making a diagnosis for cestodes. Birds that harbor only a few
worms show conditions which are quite different from those that
possess a large number. Therefore the symptoms are rather var-
iable.

Stiles (1896: 13) mentions some general principles for diag-
nosis, and Zurn (1882: 17) gives more fully some of the symptoms
that may be taken as indications of the disease in the birds.

In general, one may say that a light infection can hardly be
noticed and is apparently in no way harmful to the fowl. In
cases suffering from a moderate to a heavy infection the conditions
were found to be quite different. In the first place, birds that are
moderately infested are apparently always hungry, having in-
deed ravenous appetites and seeming never to be able to get enough
to eat. Secondly, they manifest a great desire for water, increas-
ing in cases where the infection is heavy. Moreover, infected birds
are greedy and it seems as if their hunger had caused them to lose
control of themselves whenever there is a chance to obtain any food.
Such birds are also restless, always moving about as if searching
for something. This in part probably accounts for the fact that
the fowls are poor in flesh and more or less in an emaciated con-

CESTODE INFECTION IN CHICKENS 225

dition. They are never at ease on account of their restless atti-—
tude which is apparently due to nervousness. Normal exercise
alone does not depress the condition of the bird, but rather the
constant restlessness and uneasiness which is manifested by those
that are infested.

The heavily infested chickens become emaciated and lose their
color, the feathers become ruffled, and the plumage is not glossy as
in the fowls that ave free from the disease. Growing birds that
were heavily infested, were found usually to be slender and
quite poor in flesh, the head very thin and the comb pale. In
eases of heavy infection the growing birds isolate themselves to
some extent and often allow the wings to droop and hang at the
sides. The sick birds, even though they isolate themselves, still
manifest a great desire for food and water.

A slight infection is hardly to be detected in the droppings,
but when it is heavy there is developed an irritation or inflamma-
tion of the intestinal epithelium, a kind of catarrh which results in
a diarrhea, varying with the degree of infection. This irritation
of the intestinal epithelium by the worms causes an abundant flow
of mucus into the intestine. The mucous secretion is at first a
clear, transparent semi-liquid, and sometimes slightly whitish.
Worms which are slightly transparent are difficult to see, as they
are imbedded in the mucus. Later the mucus takes on a brownish
color which is due in part to slight hemorrhages of the epithelium
caused by the irritation of the worms. This color of the mucus is
retained until it is passed out with the feces so that the droppings
of an infested bird have always a characteristic yellowish-brown
eolor. This factor of coloration in the droppings is one that can
nearly always be depended upon as a criterion of infection.

When the infection is heavy a gas is formed in the intestine
which is noticeable in the droppings in the form of bubbles. These
bubbles are present when the feces are first passed and remain in
the semi-liquid droppings for some time. This is very character-
istic in cases of heavy infection but is not noticeable at other times
except in cases of extreme diarrhea, and then.the gaseous forma-
tion is comparatively slight. In a flock that is heavily infested
nearly every dropping detected about roosting or resting places
shows the characteristic yellowish-brown color with a large number
of small gas bubbles enclosed. The infested birds pass droppings
often, though in small quantities.

226 F JOHN E. GUTBERLET
AO ie, Sie et i ie le ee Ed ee

Segments of the worms can usually be found when there is
a moderately heavy infection, and eggs can nearly always be dem-
onstrated by the aid of a microscope, but the latter method is not
practical under all circumstances. When the above methods fail
to show any signs of infection and an absolute diagnosis is desired
it may be well to take a few of the birds that show some of the symp-
toms, kill them and make an examination of the contents of the in-
testine between the gizzard and caecum. Any infection which
cannot be detected by the above methods is so slight that it is not
harmful to the birds in any way, or is so recent that the cestodes
are too small to be seen.

The best criteria for diagnosis are the emaciated condition of
the birds, the great desire for food and water, and the marked diar-
rhea with the characteristic yellowish-brown color of the droppings ;
furthermore in cases of heavy infection segments of worms can
usually be detected, though there is some degree of uncertainty in
making gross examinations for the proglottids in the feces. The
excretions from the kidneys are white in color and at times have
somewhat the appearance of the tapeworm proglottides. This may
at times be misleading to one who is inexperienced with this method
of examination. The excretion from the kidneys can be readily
distinguished from proglottids by placing the droppings in water
and breaking up the mass. Proglottids have a definite shape and
are firm, while the excretions break up into fine granules, or shreds
which are easily disintegrated by shaking.

Some of the above symptoms for cestode infection are iden-
tical with those for nematodes: the emaciated, unthrifty condition,
the ruffled, dull appearance of the feathers, and the more or less
restless attitude of the bird. The feces, however, look quite differ-
ent and often blood is passed with the droppings in eases of
nematode infection. The nematodes produce hemorrhages in the
intestine by boring into the epithelium.

Tapeworm infection is harmful according to the degree of in-
fection. A slight infection does practically no harm to the bird,
but when there is a heavy infection the condition is more serious.
The intestinal inflammation or catarrh is quite a serious matter
and in many cases may prove fatal. It brings on a more or less
anaemic condition and the bird’s general health is run down. Such
a condition is suitable for the coming in of other diseases, since
the fowl is unable to ward them off because of its weakened state

CESTODE INFECTION IN CHICKENS 227

of health. Through these means the tapeworms are most harmful,
as their effect works more or less indirectly with other diseases.

I have found instances where the worms were so numerous
that they would form such a large compact mass in the intestine
as to interfere with passage. These masses imbedded in a great
quantity of mucus become lodged at the junction of the small and
large intestines with the caeca.

One species, Davainea echinobothrida, produces nodules or
ulcers in the intestinal wall which are often mistaken for other
diseases. This has a more serious effect upon the chickens than
some of the other species as it has more of a direct pathological
effect.

Chickens infested with any of the species of common tape-
worms deyoured great quantities of food, but upon examination the
intestines were usually found empty. It seems as if the food
material after reaching the intestine rushes through rapidly on
account of the large amount of mucus and the marked diarrhea.
This does not allow the bird to obtain as much nourishment as it
would otherwise. The cestodes of course absorb their nourishment
from the chyme in the intestine. Furthermore, the excretions from
the worms may also have some effect upon the general health of
the bird, as some are without doubt resorbed into the system from
the intestine.

More practical proof must be obtained by experimental study
on the various effects and symptoms of infection in chickens before
much can be definitely said on the subject. As yet there is but
little known in regard to definite symptoms and effects except in a
general way.

MeruHops oF Controu. The subject of the control and treat-
ment of tapeworm disease in chickens has not been studied exten-
sively. There is need of more experimental data before much can
be said concerning it. Several remedies, however, have been tried
with some degree of success, although they do not seem practical
when large numbers of birds are to be treated.

A practice general among poultry raisers is to isolate a sick
bird and leave it to cure itself, or to kill it. Most poultry men do
not take the trouble to treat a sick bird nor do they even try to
find out the cause of its ailment, but simply say that it has ‘‘gone
light.’? Such an expression covers a multitude of diseases pre-
valent among poultry. Birds that are heavily infested with worms

228 JOHN E. GUTBERLET

isolate themselves and become emaciated. They are also said to
have ‘‘gone light.’’

As the first prerequisite for carrying on any sort of treat-
ment for worm diseases, the infected birds must be isolated from
the rest of the flock so that the latter can be kept free from con-
tamination. The droppings from the sick birds must be cared
for or destroyed in some way so that the embryos of the worms are
killed and insects prevented from feeding on them. In general
for any flock, preventive measures should be taken against infection
of all kinds by keeping the surroundings clean and sanitary; all
droppings around roosts should be collected often or subjected to
such treatment as will render them harmless or inaccessible to in-
sects. Wherever an infection is present, even if only slight, such
preventive measures should be taken to eliminate all possibility of
its further increase. One of the best is to collect the droppings
about the coop daily and place them into vats or cans that are in-
accessible to insects or worms; they are then treated with lime
or some substance which destroys the embryos. Lime or ashes
should be scattered over the droppings around the roosts and the
resting places of the birds. This destroys the embryos and keeps
insects from feeding upon the droppings. Furthermore, if the
droppings are covered with lime and collected often it will prevent
insects from breeding in them. House-flies especially, lay eggs in
chicken manure if the droppings are not treated with lime.

Other features in the habitat of the birds should be kept
sanitary; such are the feeding places and drinking vessels. Water-
ing troughs should be so placed that the birds cannot get their feet
into them, as they may carry in eggs or embryos of other para-
sitic worms (nematodes) which will reach the birds again through
the water if the latter is allowed to stand in a filthy condition.

The location of poultry yards should be changed from time to
time if possible, because if the same grounds are used from year
to year some of the insects that may be the intermediate hosts of
the tapeworms may become numerous and thus increase the possi-
bility of infection. Embryos of parasites or germs of certain dis-
eases remain on the premises from year to year, and if the yards are
changed, more healthful conditions are produced for the birds.

In addition to destroying the eggs and embryos of parasites
in the droppings, it is fully as important to destroy the adult in-
sects and their breeding places. The life history of only one spe-

CESTODE INFECTION IN CHICKENS 229

cies of tapeworm has been worked out in the United States, as is
discussed elsewhere in this paper. This species is known to have
its intermediate stage in the house-fly. House-flies breed commonly
in bird or horse manure, or any decaying vegetable matter. The
destruction of all such breeding places is a difficult matter and
little can be done along that line or with the destruction of adult
_ flies. However, fly traps* can be placed over the windows of the
chicken coop and many flies caught and killed.

According to Stiles (1896:18), the principal remedies that
have been used for the removal of tapeworms from poultry are
such drugs as extract of male fern, turpentine, powdered kamala,
areca nut, pomegranate root bark, pumpkin seeds, and sulphate of
copper. These have been experimented with to a certain extent
and have been found to be satisfactory in some instances.

The experiments with these remedies have been worked out
on individual birds. Each bird must be treated individually.
While such methods of treatment are thorough, they are not prac-
tical for a poultry raiser who has an infection in a flock of several
hundred birds. It would require handling each bird separately
two or three times, and demand a considerable amount of time; too
much to be practicable on account of the expense involved.

I tried experiments on a number of birds to see whether a
more practical method could be found. It had been observed
previously that hogs infected with worms could be freed from them
by feeding the ashes from corneobs. The ashes contain a large
amount of sodium and potassium carbonate. Lye is made from ashes
and of course contains similar substances, together with sodium hy-
droxide.

The following experiment worked very successfully: Fifteen
birds which showed symptoms of tapeworm infection were placed
in a cage which was insect-proof and were given the following
treatment; A gallon of a mixture of wheat and oats, to which
was added a small tablespoonful of concentrated lye, was cooked
slowly for about two hours and allowed to cool. The birds were
fasted for about fifteen hours and were then given as much of the
mixture as they would eat, with plenty of water. Twelve hours
later one of the birds was killed and an examination of the small
intestine was made. It was found that nearly all of the worms in

*Such as described by F. C. Bishopp, Farmers’ Bulletin No. 540, 1913.

230 JOHN E. GUTBERLET

the intestine were loose, the scolices being detached from the wall,
and were also apparently dead. The rest of the birds were given
a second dose twenty-four hours after the first. Many worms had
passed with the droppings in from twenty-four to twenty-six hours
after the first feeding. Most of the worms in these droppings
were dead, but in all probability the embryos were still alive in the
mature proglottids. Twelve hours after the second dose was given
another bird was killed and it was found that only a few worms were -
left and all of these were detached and dead. The intestine was
filled with a peculiar gray colored, slimy substance composed mainly
of mucus. Many entire worms and fragments were passed with
the droppings during the period of the feeding. The lye acted to
some extent as a purgative.

The birds, were given normal diet again, and in a few days
they showed no symptoms of infection. Hight days after the sec-
ond dose two more birds were killed and examinations made. One
possessed a small fragment of a tapeworm and the other was en-
tirely free.

The effects of such treatment upon the flock as a whole were
shown later. While I was carrying on other investigations with
chicken cestodes my father noticed that the birds were very heav-
ily infested with worms. In an endeavor to free the birds of the
worms and to improve their general condition he fed them a mix-
ture of cooked grain and lye on July 15, unknown to me. As a
result the entire flock of nearly four hundred birds was practically
freed from the worms by a single application of the remedy. The
cestodes were so thoroughly removed that there were not enough left
to allow me to go on with my investigations and my observations on
the worms were not taken up again until August 10, when the birds
had become infested again and the parasites had grown to such size
as to enable the continuance of my work.

This remedy is a very simple one and is practical. It has
been known to many poultry raisers for some time, but they have
neglected to use it, mainly on account of the fact that heretofore
no definite evidence has ever been presented concerning its actual
working possibilities. It may not, and in all probability will not,
remove all the worms, but it does remove most of them so that they
are not serious and ean be controlled in the flock as a whole.

In a large flock the birds can be housed for the length of
time required for the fast, then fed on the cooked grain and kept

CESTODE INFECTION IN CHICKENS 231

in the house until after the effects of the second dose have passed
off. During the time that they are confined the droppings should
be collected often and lots of lime used about the coop and over
the droppings to keep away the insects. In a flock the treatment
would have to be repeated from time to time whenever the birds
became infected again. Further experimental evidence must be ob-
tained before much can be said in regard to details of this method
of treatment, especially as to the amount of the alkali to be used.
A large amount would be harmful to the intestinal mucosa, while a
small amount would have little if any effect upon the parasites.

FEEDING EXPERIMENTS FOR INFECTION. Chickens in the vicin-
ity of Hardy, Nebraska, were heavily infested with tapeworms, and
young birds were found to be more heavily infested than the adults.
This led to investigations concerning the reason for the difference
in the infestation of the adult and young birds when they were to-
gether in the same environment and fed on the same diet.

The summer of 1913 was very dry in the locality which was a
factor in keeping the numerous varieties of insects down to a min-
imum, because the drought interfered with their breeding. Upon
observation it was found that only two kinds of insects were present
in any abundance about the haunts of the birds. Those were the
ground beetle Tenebrio and flies. The stable fly, Stomoxys calct-
trans, which usually breeds in wet, decaying straw, was very scarce
because its breeding places had dried up. The house flies were
very abundant everywhere.

The reason why the adults should be only slightly infested
with parasites, while the young and growing birds harbored so many,
was then the subject for observation. The birds were watched in
their haunts and their habits studied. It was soon noticed that
the young birds, when in their resting places in the shade of a tree
or a building, were busy the whole time pursuing flies and very
often caught their prey, while the adults paid little or no attention
to the flies. This led to the conclusion that flies might have some-
thing to do with the transmission of the worms to the birds.

With a view to testing this hypothesis, experiments were car-
ried on with the worms that were most common in the birds.
These species were Davainea cesticillus, Davainea tetragona, and
Choanotaenia infundibuliformis.

Segments of these worms were teased apart so that the eggs or
embryos were set free in a drop of water, and this was fed to flies

232 JOHN E. GUTBERLET
ag SS Es TD Nae
of the species: Musca ea case Stomoxys calcitrans, and Calli-
phora vomitaria.

Only a few Calliphora could be obtained and these did not
live long under experimental conditions. This species of fly does
not frequent places where it would be likely to become the inter-
mediate host of any of the chicken cestodes, as it always remains in
cool, damp, and usually dark places, unless it can find carrion.
However, on cool, dark, damp days it does appear in chicken yards,
but its occurrence there is‘not frequent. Some Stomoxys were used,
but in no case did they live long in captivity.

Musca domestica lived much longer than either of the others,
even though it was difficult to keep them alive for a long period.
After a great deal of experimentation it was found that they could
be kept alive in a cage for twelve or thirteen days, and in one ex-
treme case some were kept alive for twenty-one days. The flies in
captivity were fed on blood, liver and spleen. These were found to
be the best foods.

The oldest proglottids on the worm were usually taken for
feeding to flies, and also some of the free segments in the intestine
were used. The use of the oldest proglottids proved to be an error
in the case of Choanotaenia infundibuliformis, because it was found
later that in this species the oldest segments separate from the
worm before they are entirely mature, but proglottids that have been
free in the intestine for some time may be mature. The use of
proglottids that were not entirely mature for feeding flies was an
error in my experiments which may account for so few infections.

DAVAINEA CESTICILLUS. In a series of experiments 107 flies of
the species Musca domestica were fed on the eggs from proglottids
of Davainea cesticillus. Some were killed and preserved each day
from the beginning of the experiment until the tenth day, when the
remaining flies died, except in one case four were kept alive for
twenty-one days. These were all sectioned with the exception of
five, which were dissected. No stages of the cestodes were found in
any of the flies when examined.

During the experiment microscopic examinations were made of
a great number of the droppings of the flies and no eggs or embryos
of the worms could be found in any ease. It is certain that the
flies got some of the eggs because they were numerous in the mater-
ial that was fed to them. The flies would lap up all the water in
which the eggs floated and would then suck on the fragments of

CESTODE INFECTION IN CHICKENS 233

proglottids. In several instances when the flies were hungry it
was observed that they would take small fragments of the proglot-
tids between the labella of the labium and actually devour them.
Since the eggs are microscopic in size it is practically certain that
the flies got some of them.

Several Calliphora were fed on eggs from this species, but
these flies lived for only two or three days.

Proglottids of this tapeworm were fed to a number of beetles
of the species Tenebrio melitor. The beetles ate the segments
readily. Some were killed at the end of one week, others at two
weeks, and the rest at three weeks. These beetles were sectioned,
but showed no developmental stage of cestodes.

DAVAINEA TETRAGONA. In experiments on this species 59 flies
in all were used. Some of these were killed and preserved after
from two to twelve days. The proglottids were broken up and
the eggs set free in a drop of water. The flies lapped up the water
with the eggs and afterwards sucked all of the moisture from the
fragments of the proglottids. Therefore, it is very probable that
the flies got some of the eggs. Microscopic examinations of the
droppings of the flies showed no signs of eggs.

Material would pass through the flies in a few hours as was.
demonstrated by feeding them on blood. When the flies gorged
themselves with blood they passed red droppings in from eight to
ten or twelve hours. This indicated the length of time that it took
material to pass through the alimentary canal. In this way the
approximate time to make fecal examinations for the eggs was de-
termined. However, examinations were made of the droppings
after five or six hours as well as later and at regular intervals of
two or three hours.

The flies were fed on eggs once or twice each day for three days.
When they were fed once a day that was done in the morning, and
when fed twice they were given one dose in the morning and the
other at noon. On three occasions some flies were fed in the even-
ing and fecal examinations were made the next morning and con-
tinued at intervals of two or three hours.

The flies were all sectioned and examined, but showed no stages
of the cestodes in any instance.

Some Calliphora were fed upon the eggs of this species, but
they did not live more than two or three days. Some beetles, Z'en-
ebrio, were fed on proglottids, but upon examination they showed
nothing.

234 JOHN E. GUTBERLET

CHOANOTAENIA INFUNDIBULIFORMIS. Eggs of this species were
fed to 88 flies of the species Musca domestica. Besides these some
Stomoxys calcitrans were also fed, but these did not live long in
captivity. The individuals of Musca domestica used in these ex-
periments lived from two to seventeen days. Two flies lived for
twelve days and four for seventeen days. The proglottids were
broken up and fed to the flies in the same manner as in the other
species mentioned. All of these flies were sectioned and examined.
One fly preserved at the end of twelve days showed five cysticerci.
These cysticerci agree very closely with the structure of the adult
of this species, and the hooks are identical. This cysticercus is de-
scribed in detail in another paper.

Grassi and Rovelli (1892: 33) found ecysticerci in flies which
they compared with this species. They found that there was a close
agreement in structure between the cysticerci they discovered and
the adult of Choanotaenia infundibuliformis. They therefore in-
ferred that the larva they had was the intermediate stage of this
species, but did not demonstrate experimentally its connection with
the adult tapeworm.

During the process of my experiments I had eet, to be able
to feed some chicks on flies that had been previously fed on tape-
worm eggs, but as it was so difficult to keep the flies alive under ex-
perimental conditions such an experiment could not be carried out.
However, another feeding experiment was tried with the following
results: Six chicks were taken from the nest as soon as they were
hatched and placed in a cage where they could get no insects and
great care was taken during feeding so that no flies could enter.
Fhes (Musca domestica) were caught around the chicken roosts and
fed to three of the chicks. The other three birds were used as a
control and were given no flies. Fifty flies were fed to each of
the three chicks. Three weeks after feeding, the chicks were killed
and examined with the result that two were found to be infested
with Choanotaenia infundibuliformis. One bird possessed six
worms. These were of the same length, being 35 mm. long, and each
one contained 103 proglottids. The other bird had one worm of
the same species, but it was a little longer, 43 mm. and having 118
proglottids. This bird was fed on the flies three days before the
one sheltering the six worms. The three birds which were used as
a check on the experiments contained no worms when killed and ex-
amined.

CESTODE INFECTION IN CHICKENS 235

These six birds were kept together in a cage and were fed on
corn meal and bread crumbs. The three birds that were fed. flies
were caught and the insects were given to them from the hand.

A number of stable flies (Stomoxys calcitrans) were used in
the experiments with this species of worm, but they would not live
under experimental conditions for any length of time. They would
usually die within 24 to 36 hours, except in one case when six lived
for five days. They were sectioned, but nothing could be found.

On numerous occasions I have observed maggots in the drop-
pings beneath the chicken roosts. Now, since house-flies are in the
habit of breeding in such places, it seemed possible that infection
might take place in the maggot stage of the flies. Experiments
were then tried with the maggots of Musca domestica and Stomoxys
caleitrans. Thirty Musca domestica maggots were fed on segments
of three species of cestodes, Davainea cesticillus, Davainea tetra-
gona, and Choanotaema infundibuliformis. The maggots devel-
oped puparia in a day or two. Some were sectioned in the pupa
stage. The rest developed into adults and were sectioned, a few
were dissected, but only negative results were obtained. Fifty
maggots of Stomoxys calcitrans were fed on proglottids of the same
three species of tapeworms. The maggots went into the pupal stage
within two or three days. Some were sectioned in the pupal stage.
Most of them developed into adults and were sectioned while a few
were dissected. No positive results were obtained from either pupal
or adult stages.

From the foregoing it seems probable that flies are not the
intermediate hosts for Davainea cesticillus and Davainea tetragona,
as the experiments that I have carried on with them are extensive
enough to appear conclusive. However, the small number of vari-
eties of insects present in the locality seems to throw the burden
upon the flies, since they were so abundant and observations show
that they are taken and eaten by the chickens that are most heavily
infested. The adult birds eat all other insects that are easy to
eatch, but since the flies are more difficult to take as prey they
leave them alone. If the infection is direct, the adults would have
fully as much chance as the young birds because they get food and
water together and have the same environment.

In the case of Choanotaena infundibuliformis it seems to be
clear that the house-fly is the intermediate host. Grassi and
Rovelli hold that it is the intermediate host on a purely structural
basis. My experiments show that it is certainly an intermediate

236 JOHN E. GUTBERLET

host in some cases. Furtherwore, feeding chicks on flies that were
taken from about the chicken roosts and raising the cestodes make
it probable that the house-flies are the intermediate hosts of this
one species.

The reason why more flies were not infected by feeding on
the eggs of this species was determined to be peculiar conditions in
the maturing of the proglottid. At the time when the experiments
were being carried on it was not known that the oldest proglottids
separated from the worm before they are entirely mature. In the
experiments the oldest proglottids on the worm were usually taken
for feeding, though in some cases the free segments in the intestine
were used. Since the flies were fed on eggs that were not entire-
ly mature the embryos were digested. The free proglottids remain
in the intestine of the bird for some time and in all probability
mature there. Some such free proglottids were examined and found
to contain mature embryos.

SUMMARY

1. The results of these experiments show that the intermediate
(eysticercoid) stage of Choanotaenia infundibuliformis occurs in the
common house-fly Musca domestica. The results were obtained by
feeding flies on eggs of the tapeworm and raising cysticereoids in
a fly; also by feeding chicks on flies and raising the worms in the
birds. By morphological comparison of the cysticercoid and adult
they are shown to be identical. Results from experiments by feed-
ing flies on eggs from Davainea cesticillus and Davainea tetragona
were negative.

2. The habits of the birds are important factors to be con-
sidered in experimental work for life history studies. Certain in-
sects are found in great numbers around chicken houses and
_ yards and are readily eaten by the birds. Flies are known to con-
tain the larval stage of one species of cestode, and some other
species of insects are to be considered as probable intermediate
hosts for other species of cestodes.

3. The symptoms and effects of the infection from tapeworms
vary with individual birds, age of birds, and the degree of infee-
tion. Birds infested with worms display an emaciated, unthrifty
condition, an unnatural desire for food and water, and a marked
diarrhea with: droppings of a characteristic yellowish-brown color.

4. The control of tapeworm disease in chickens is in an unset-
tled condition. Little can be done until more is known concerning
life histories of worms, Preventive measures are urged rather

CESTODE INFECTION IN CHICKENS 237

than curative measures. Droppings should be cared for and treated
with appropriate substances in order to prevent insects from feed-
ing on them or developing in them. Experiments by giving lye
with food to infested chickens showed satisfactory results in re-
moving tapeworms.

5. The flocks of chickens that were studied showed at times a
very heavy infection and nearly every bird examined harbored one
or more species of worms. Five species were found in the chickens
at Hardy, Nebraska, and three in the birds at the poultry farm at
the University of Illinois. The species found in Nebraska are
Davainea cesticillus (Molin), Davainea tetragona (Molin), Davainea
echinobothrida (Megnin), Hymenolepis carioca (Magalhaes), and
Choanotaenia infundibuliformis (Goeze). At the poultry farm of
the University the species Davainea cesticillus (Molin), Davainea
echinobothrida (Megnin) and Hymenolepis carioca (Magalhaes)
were found.

6. A full description of the structure of these parasites has
been published in the Transactions of The American Microscopical
Society, Vol. 35, p. 23-44, Pl. 5-8.

a
BIBLIOGRAPHY

GRASSI, B. B. and Rove, G. 1889. Embryologische Forschungen an Ces-
toden. Centralbl. f. Bakt. und Parasitenk, 5:370-377, 401-410.
1892. Ricerche embriologiche sui Cestodi. Atti Accad. Gioenia di Sci.
Nat. in Catania, 4:1-108.

PIANA, G. P. 1882. Di una nuova specie di Tenia del gallo domestico (Taenia
bothrioplitis) e di,un nuova cisticerco delle lumachelle terrestri (Cysti-
cercus bothrioplitis). Mem. Accad. Sci. Inst. Bologna, 2:387-394.

Ransom, B. H. 1900. A new Avian Cestode—Metroliasthes lucida. Trans.
Amer. Micr. Soc., 21:213-226.

1902. On Hymenolepis carioca (Magalhaes) and H. megalops (Nitzsch)
with Remarks on the Classification of the Group. Trans. Amer. Micr.
Soc., 23: 151-172.

1904. The Tapeworms of American Chickens and Turkeys. Bur. An. Ind.
Ann. Rpt., 21: 268-285.

1909. The Taenoid Cestodes of North American Birds. Bull. U. S. Nat.
Mus., 69: 1-141.

Rosseter, T. B. 1891. Sur un Cysticercoide des Ostracodes, capable de se de-

velopper dans 1’intestin du Canard. Bull. Soc. Zool, France, 16: 224-229.

1892. On a New Cysticercus and a New Tapeworm. Journ. Queckett
Micr. Club, 4: 361-366..

1897. On Experimental Infection of Ducks with Cysticereus coronula
Mrazek (Rosseter), Cysticercus gracilis (von Linstow), Cysticereus tenui-

rostris (Hamann). Journ. Queckett Micr. Club, 6: 397-405.

Scumipt, J. EH. 1894. Die Entwicklungsgeschichte und der anatomische Bau
der Taenia anatina (Krabbe). <Arch. f. Naturg., 1894, 1: 65-112.

Stines, C. W. 1896. Report upon the Present Knowledge of the Tapeworms
of Poultry. Bur. An. Ind. Bull. No. 12; 78 pp.

Tower, W. L. 1900. The Nervous System of the Cestode Monezia Expansa.
Zool, Jahrb., 13: 359-384.

Zizn, F. A, 1882, Die Krankheiten des Hausgefliigels. 237 pp., 76 figs.
Weimar,

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VEDA

John Earl Gutberlet was born in Nebraska in March, 1887.
He received his preparatory training in the high school at Hardy,
Nebraska, and at Bethany Academy, Lindsborg, Kansas. He
entered Bethany College, Lindsborg, Kansas, in 1905 and received
the A. B. degree from that institution in 1909. During the year
1909-10 he was a graduate student and an assistant in the
department of Zoology at the University of Colorado. He
attended the summer session of the University of Colorado
Biological Station in 1910. In the fall of 1910 he went to the
. University of Illinois where he accepted a position as assistant
in the department of Zoology which he held until 1913. He
received the A. M. degree from the University of Illinois in 1911.
During the summer of 1911 he was engaged in study at the Marine
Biological Station, La Jolla, California. He was elected to mem-
bership in the I]linois Chapter of Sigma Xi in 1912. He attended
the summer session of the University of Illinois in 1918. During
the year 1913-14 he held a fellowship in Zoology at the Univer-
sity of Illinois where he completed his work for the degree of
Doctor of Philosophy in June, 1914.

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