DOCTORAL

D IS S E R T A T IO N

S E R IE S

Helation Setu/een Sije And
of The Fowl Cloaca, 7hiTsa„ A n d Gona&
xv'tlh Special Deference To G r o w t h

TITLE,

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AUTHOR
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MICHIGAN

RELATION BETWEEN SIZE AND AGE OF THE FOWL CLOACA, BURSA,
AND GONADS WITH SPECIAL REFERENCE TO GROWTH AND
STRUCTURAL VARIATIONS IN THEIR CONSTITUENT
PARTS FROM HATCHING DATE TO SEXUAL
MATURITY

by

Clare Helmer Bennett

An Abstract of
A Thesis Submitted to the Graduate Faculty
for the Degree of
DOCTOR OF PHILOSOPHY

Approved:

( £ /7'c

In Charge of Major Work

Dean of Graduate College
Michigan State College
19U

RELATION BETWEEN SIZE AND AGE OF THE FOWL CLOACA, BURSA,
AND GONADS WITH SPECIAL REFERENCE TO GROWTH AND
STRUCTURAL VARIATIONS IN THEIR CONSTITUENT
PARTS FROM HATCHING DATE TO SEXUAL
MATURITY

CLARE HELMER BENNETT

Investigation of the avian cloaca has been a subject of intensive
interest to relatively few workers during the past two hundred and fifty
years.

•Review of the literature shows that the anatomy of the cloaca and its
size in relation to the size of the bursa and gonads in various age groups
of Aves is fragmentary. Additional observations on the cloaca of birds from
hatching time to sexual maturity are desirable.
The study is based on the cloacas of one hundred eighty-one pedigreed
Single Comb White Leghorn chickens, three Hungarian partridges and two Ring­
necked pheasants.
Results of the study showed:
1. The cloaca of the fowl, partridge and pheasant consists of three
compartmentsj the coprodaeum which was the largest, the urodaeum which was
the smallest and the proctodaeum which was smaller than the coprodaeum yet
larger than the urodaeum.
2. The cloacal compartments and their limits were similar in the three
species studied. The position of the cloacal papillae was likewise similar.
All species showed the bursa connected to the proctodaeum by a funnel-shaped
canal. A broad fold was observed in the proctodaeum of the fowl, partridge
and pheasant.
3* A deep coprodael pocket and a uretal vestibule were observed in the
partridge while an oblique coprodael fold was seen in the fowl and pheasant.
Uretal papillae in the pheasant were found on the anterior edge of longitu­
dinal folds and were not disc-shaped as in both the fowl and partridge. The
bursal aperture was exposed in the partridge while in the fowl and pheasant
it was covered by the uro-proctodael fold.
A. Growth in size of the cloaca when measured in percentage increase in
length and width was greater in the female than in the male.
5- Maximum size of the cloaca in the male and female fowl was reached
from the 131 st to I56 th day of age,
6.
Growth in the individual compartment of the cloaca showed that the
coprodaeum in the male and female fowl increased rapidly up to the 7 Wi day
I

and remained fairly constant until the_maximum on the 131 st day. Growth in
length of the urodaeum was essentially alike in the male and female fowl until
the 59 th day and then was greater in female than in male.
7.
The increased length of the female cloaca between the ages of 156 and
195 days was due to increased length of the urodaeum.
8 . Growth in width of the female urodaeum closely paralleled that of the
male through the 131 st day but in the female increase in width was greater
from the 131 st day until the 195 th day than it was in the male for the same
period.
9. Growth of the proctodaeum was similar in the male and female from
hatching date until the 156 th day.
Following, which, the female showed a
greater increase than the male through the 195 th day.
10.
There was no significant growth in the uretal papillae from hatching
date through sexual maturity while growth in the genital papillae of the male
closely paralleled that of the female through the 32 nd day, after which the
male showed a greater increase than the female. The genital papillae in the
female showed rapid atrophizat-ion after the 131 st day,

11. The bursa reached maximum growth on the 59 th day in the male and
131 .st day in the female.
12. Results showed a correlation between bursal atrophization and sexual
maturity which on the basis of Riddle's observations may be due to prolactin.
13. There was no significant increase in the number of bursal folds
from hatching date to sexual maturity.
14.. Results of this study and those of Rowan, Bissonnette, Marshall and
Riddle suggest cloacal size is influenced by (l) endocrine factors associated
with the gonads and the anterior pituitary and (2) an exteroceptive factor
(light) which through the intermediation of the nervous system acts upon and
modifies the endocrine factors.

COPYRIGHTED
bjr
CLAPE HELMER BENNETT
1944

RELATION BETWEEN SIZE AND AGE OF THE FOWL CLOACA, BURSA,
AND GONADS WITH SPECIAL REFERENCE TO GROWTH AND
STRUCTURAL VARIATIONS IN THEIR CONSTITUENT
PARTS FROM HATCHING DATE TO SEXUAL
MATURITY

CLARE HELMER BENNETT

A THESIS
Submitted to the Graduate School of Michigan
State College of Agriculture and Applied
Science in partial fulfillment of the
requirements for the degree of
DOCTOR OF PHILOSOPHY
Department of Zoology
i9a

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Relation between S ;• end Age of the Cloaca in
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I. INTRODUCTION

Investigation of the avian cloaca has been a subject of intensive
interest to relatively few workers during the past two hundred and
fifty years-

There have been no previous attempts to present detailed

drawings of actual dissections in a series of age groups.
vrere concerned mostly with sketches and diagrams.

Early efforts

Later work has been

related chiefly to the microscopic study of the organ and its develop­
ment.
One of the earliest workers. Fabricius (1688), investigated this
structure from an embryological and developmental point of view.
Almost two centuries later Grant (1833) found that structural differ­
ences existed in the different parts of the cloaca.

Forbes (1877)

contributed to this field by studying the relations between the cloaca
and bursa in several orders of birds.
Gadow (1887) made a comprehensive study of the cloaca and re­
ported for the first time the anatomical differences in its various
parts.

This author stated that three regions could be recognized,

i.e., an anterior (l) coprodaeum, a middle (2) urodaeum, and a poste­
rior (3 ) proctodaeum.
Ward and Gallagher (1920), Groebbels (1932), MacDonald and Taylor
(’
1933), Sisson (1937) and McLeod (1939) have described the cloaca in
connection with other avian studies.

The observations reported by

these authors are in general agreement with those described in the
preceding paragraphs.
Retterer (1885) obtained measurements of the bursa during.the
height of its development.

Jolly (1915) found that the bursa reached

maximum size at the onset of sexual development and then decreased to a
vestige following sexual maturity.

Riddle (1928} investigating doves

and pigeons found that maximum bursal development was attained prior to
gonadial development.

Gower (1939), Linduska (1943) and Kirkpatrick

(1944) used the bursa as an age indicator in pheasants.
Latimer (1924), and Mitchell, Card, and Hamilton (1926) studied
the relation between body growth and gonadial growth in the fowl.
Kaufman (1927) investigated body growth and gonad growth in the common
pigeon.

Parker, McKenzie, and Kempster (1942) studied the relation be­

tween comb size and gonad size in the fowl.
The preceding review of the literature shows that the anatomy of
the cloaca and its size in relation to the size of the bursa and gonads
in various age groups of Aves is fragmentary.

Additional observations

on the cloaca in birds from hatching time to sexual maturity are de­
sirable.

Observations made in this study will be presented under five

headings:

(A) anatomy of the avian cloaca; (B) relation between size

and age of the cloaca in the fowl from hatching date to sexual matu­
rity; (C) relation between size and age of the coprodaeum, urodaeum
and proctodaeum in the fowl from hatching date to sexual maturity;
(D) relation between size and age of the bursa in the fowl from hatch­
ing date to sexual maturity; (E) relation between size and age of the
gonads in the fowl from hatching date to sexual maturity.

II. MATERIALS AND METHODS

Material was secured by the cooperation of Dr. C. A- Brandly
l

of the Regional Poultry laboratory and Professor J. A. Davison of the
College Poultry Plant.

Additional material was secured from the

Pinecroft Poultry Farm and Hatchery, Owosso, Michigan, and the State
Game Farm, Mason, Michigan.
Birds obtained from the Regional Poultry Research Laboratory were
brooded and maintained in complete confinement.

The chickens were kept

within two large brooder houses equipped with wire panel floors.

In

other houses where litter was used, the pens were cleaned as often as
necessary to keep them in good condition.

Windows and doors of the

brooder houses were carefully screened against flies, mosquitoes, and
other insects.

In addition, sparrows were not permitted to nest nor

raise their young in or about any of the buildings.

Care was exer­

cised to reduce to a minimum the presence of flies and other intro­
duced parasites by the practice of delivering feed to the different
houses through vestibules and removing droppings and litter from these
houses in large garbage cans with covers.
in these two operations.

Two sets of cans were used

All litter and droppings collected were

burned in an incinerator.
All feed was supplied in open hoppers.

Running water and drinking

fountains in each pen aided in keeping fresh, clean water before the
birds at all times.

Diet furnished the chickens consisted of a start­

ing, growing, and laying mash mixed according to the following formula:
ground yellow corn,

ground medium oats,

wheat bran, 15J6; dried skim milk,

meat scrap,

wheat middlings, \ % \
sardine meal,

soybean oil meal, 5%; alfalfa leaf meal, 5%; oyster shell flour, 2%;
salt mixture (iodized salt and anhydrous manganous sulphate), 0 .65%;
fortified cod liver oil (400 AQAC chick units D, 3000 I. U. units A per
gram), 0.35%; insoluble grit, 1%.

In addition to the above, all birds

over eight weeks of age were fed (in hoppers in mid-afternoon) the fol­
lowing grain mixture:

cracked yellow corn, 50%; oats, 25%; wheat, 25%.

All chickens were pedigreed Single Comb White leghorns.
of ten age groups was obtained.

A series

In every series an attempt was made

to have at least ten birds of each sex for each age group; however in
some series it was not physically or economically possible to do so at
the time this study was made.

In obtaining the data which will be

given in the following pages eighty five males and eighty six females
were dissected.

Birds were killed by cervical fracture or electrocu­

tion.
The cloacas studied were obtained by the following methods:

A

longitudinal incision, three inches long, ivas made in the skin midway
between the legs and body.

The legs were pulled down and away from

the body disarticulating the hip.

A transverse slit two to four

inches long was made Just behind the xiphoid process of the sternum.
The skin was pulled forward and to the side, exposing the sternum and
the muscles of the abdomen.

By means of a pair of heavy scissors a

transverse incision was made in the muscles posterior to the xiphoid
process.

The incision was continued anteriorly and dorsally at its

right and left extremities until the sternum was freed at its ante-"
rior border; then it was deflected anteriorly or entirely removed.
Visceral structures anterior to the heart were sectioned transversely,
after which they were deflected caudally.
tachments were then severed.

Visceral and heart at­

The gonads were removed and placed in 10%

solution of formalin.
The cloaca was removed from the coelomic cavity by freeing its
attachment to the anal sphincter.

The structure was then pulled outward

until the recto-cloacal junction was exposed.

Severance of the cloaca

from the rectum was made anterior to the junction.

Cloacas removed in

this way were labeled and stored in 10$ solution of formalin.
The cloaca of each specimen, in preparation for its study, was slit
along either the mid-ventral or mid-dor3al surface from a point a little
beyond the recto-cloacal junction to the free border of the anal
sphincter.

The free edges of the slit were pinned back, allowing a

complete view of all compartments and their adjoining structures.
The pinning was done upon a special cork surfaced dissecting box,
which was improvised to fit over the stage and base of a BKW Wide
Vision Bausch and Lomb Microscope.

Ordinary common pins and sizes 00,

0, 3, and 5 insect pins were used.

For very fine work concerning the

smaller folds and papillae, sizes 00 and 0 were used.
All dissections were made at 7X using a BKW Wide Vision Bausch
and Lomb Microscope.

Measurements were obtained by use of metal di­

viders and recorded in millimeters.
inch millimeter rule was used.

A standard, white celluloid, six-

In determining the diameters of the

compartments of the cloaca, a longitudinal incision was made along
either the mid-ventral or mid-dorsal region.

The free borders of the

cloaca were then pinned back, care taken not to alter the size of the
chambers by undue stretching.

This procedure allowed full view of all

compartments and structures within the cloaca.
Due to the fact that the cloacas had previously been placed in
a 10$ formalin solution, which hardened the tissues, the original posi­
tion of all folds and structures was preserved.

In determining the

diameters of the compartments it was necessary to measure only the dis­
tance between their lateral walls, the original position of these walls
being made conspicuous when the interior of the cloaca was exposed.
Measurements made on cross sections of the various compartments of
cloacas, indicated that the above procedure was fairly accurate.
Structures were weighed on an analytical balance and results were
recorded in milligrams.

Measurements and weights taken for each age

group and for each sex were averaged.

A study was then made of the

difference found between the different age groups of each sex and be­
tween the sexes themselves.
Sketches were made from the actual dissections, which were pinned
down and held in place on standard 7f x 11 wax bottom dissecting pans.
As considerable time elapsed during the period these dissections were
being sketched, it was necessary to keep the specimens preserved and
in proper position at all times.

Because of this, the specimens to

be sketched were kept pinned in position and covered with a 6% solu­
tion of formalin.

This strength was chosen as being suitable for pre­

serving the tissue and eliminating molds, yet not being of sufficient
strength to affect one moderately sensitive to the odor of formalin.
Glass plates were cut to size to fit over these pans so that the
specimens to be sketched could be kept on hand at all times and availa­
ble for study and comparison.

III. OBSERVATIONS

A. Anatomy of the Avian Cloaca

All observations given in this section were made as described in
the preceding pages. Observations made

are shown in Plates I, II, and

III.

1. FOWL.

The cloaca of the fowl is the posterior termination of

the digestive system.

It lies within a U-shaped cavity bounded dor-

sally by the caudal vertebrae and posteriorly by the posterior third of
the sacrum and laterally by the caudal processes of the ilia.
ventral surface lies free within the abdominal cavity.

The

The cloaca is

a funnel shaped structure which is attached anteriorly to the rectum
and posteriorly to the body wall.
Ventral aspect. Plate I, Figure 2shows that the coprodaeum
(b) is the largest and mostanterior of

the cloacal compartments.

It

is triangular in shape and limited anteriorly by the recto-coprodael
junction (d). longitudinal folds (o) at this junction suggest the
presence of a sphincter.
of Gadow (1887).

This is in agreement with the observation

Calhoun (1933) however did not find a definite

sphincter at this junction.

Posteriorly the uro-coprodael fold (e)

separates this chamber from the urodaeum (1).

Plate III, Figure 3

shows that the coprodael surface of the uro-coprodael fold (e) is
lobulated at its free margin and membranous.

It forms an orifice

which in some specimens is circular and in others it is elliptical.
Plate I, Figure 2 shows that the urodaeum is posterior to the

/'•virn Clo?.ca«.

male.

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Figure 3

Figure 4

coprodaeum.

It is rectangular in shape and smaller than either the

coprodaeum or the proctodaeum.

Anteriorly this chamber is limited try

the uro-coprodael fold (e) and posteriorly by the uro-proctodael fold
(j).

This is in agreement with the observations of Forbes (1877) and

Gadow.

located on the median dorsal wall of the urodaeum are the uretal

apertures (f and f') which are found either on the surface of disc­
shaped papillae or longitudinal folds.

Lateral to the uretal apertures

are located cone-like genital papillae within pocket-like depressions.
These observations are in agreement with those of Forbes.
It is likewise perceivable from Plate I, Figure 2 that the most
posterior chamber of the fowl cloaca is the proctodaeum.

It is rec­

tangular in shape and larger than the urodaeum, yet smaller than the
coprodaeum.

Anteriorly it is separated from the urodaeum by the uro-

proctodael fold (j).

Posteriorly it is limited by the anal sphincter.

Extending along the mid-dorsal wall of the compartment from the uroproctodael fold to the anal sphincter is the broad fold (i), the an­
terior border of which is covered by the uro-proctodael fold.
Dorsal aspect.

Plate IT, Figures 3 and 4 show 'that the dorsal

aspect of the cloacal compartments is essentially the same as that
described for the ventral aspect.

Observations made in this section

suggest that the urodaeum can be divided into right and left moieties
by the v-shaped uro-coprodael fold (e).

Each moiety contains medi­

ally; a cone-shaped genital papilla (g) within a genital pocket (m)
and laterally a uretal papilla and aperture (f).

Further observa­

tions reveal that the uro-proctodael fold is less developed on the
ventral wall of the urodaeum than on the dorsal wall.

This observa­

tion is in agreement with that of Gadow who found that the "sphincter
vesicle of Martin St. Ange" (uro-proctodael fold) was best developed

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Figure 4

on the dorsal and lateral walls of the urodaeum.

The proctodaeum (h)

is almost completely covered by the uro-proctodael fold.

This fold

whose apex contacts the apex of the uro-coprodael fold completes the di­
vision of the compartment into right and left halves.
uro-proctodael fold is fused to the proctodaeum.

Mid-ventrally the

Observations shown in

Figure 4 reveal that the bursa (c) is attached to the dorsal surface of
the proctodaeum (h).

In Figure 3 the bursa is attached and almost com­

pletely covered by the deflected portion of the proctodaeum.
Sagittal aspect.

Plate III, Figure 4 shows that anteriorly the

coprodaeum (b) largest of the compartments is separated from the rectum
(a) by a narrowed area, the recto-coprodael junction (a).

The oblique

fold (s) which arises from the inner ventral surface of the coprodaeum
and extends dorso-caudally along the lateral wall of the chamber further
suggests the presence of this junction.

This agrees with the de­

scription given by Kaupp (1918) who used this fold as a means of iden­
tifying the recto-coprodael junction.

Posteriorly the uro-coprodael

membrane (e) separates this chamber from the urodaeum (l) which in this
aspect appears as large as the proctodael chamber (h).

On the ventral

lateral wall of the urodaeum is a cone-like genital papilla (g) within
a pocket-like depression.

Just dorsal to the genital papilla is the

uretal aperture (f) located on the tip of a papilla-like fold.

Poste­

riorly the urodaeum is limited by the uro-proctodael membrane (j)
which separates this chamber from the proctodaeum (h).

The procto­

daeum is limited anteriorly by the uro-proctodael membrane 4j) and
posteriorly by the anal wall.

The bursa (c) is connected to the dorsal

surface of the proctodaeum (h) by means of a funnel-shaped canal (q).
Within the bursa are longitudinal mucosal folds (p) which extend along
the walls from the dorsal surface to the canal.

These observations

PLAT!-: T H

frlm

cJ.or.r-r' ana uro-coprodael aperture*

Figures 1 end 2.

Sagittal aspect; Hungarian Partridge.
Figure
Figure 2, female; age 36 days.
Upper portion
of bursa has been removed to s!.-;o, reir ti.onship of c? nr 1 . 1 q v

lf male; age 59 days;

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1

1,

(a.; roctux;; (b) coprodaeum; (c) b u r s a ; (n) roeto--eoproaneI j unc­
tion; (e ,
. uro-copn >dn e.i. f’o {d ; (f; in-? to !. pa pi.! !.a. «<i th a.per t uro; (g)
genital pe.pidd a (h) proc laoo.a eurr : (j "» ’. r : - n n ” ‘a-'dael fold; fir nnrr ;
( l ; u roc :*e’ra; (p) tuiar- 1 i'oi.as;
of

o r ec fo.'i-a earn

(s '

o ld io u e

(q) tuiO'-': i etna L;

c,-p a 0 c

(r ; no s ter Lor w - 11

15

,/S ,

CL

*

1
EL

Figure 1

e
Figure 2

Figure 3

Figure U

«.o)‘ee!neTih t»/Lr.'i those of Forbes, Gadow. Or o ebb-2Is (I93?h and
v .-,p T= v

; (in "9).
mode on the cl.na.cn of the fo'"l chow th" t the roprodneum

i n t-,e n’
.ost v,-,tori or and U,rarest of

It is so;0 ""teii

thecom r.-r tmeni s .

anio'-'i o r !.y from the rectum by a rncbi-cay’:dael junction and obf ion® fold
Do~

o r -1 y

it

•To .•■r••n ' t e r r o r *

r•'

t"n-y

i. - r e p « r n

to tan;:

'■vmata ,

tod from theurodao’.rr. by

coprobaeurr.
It. ~

is

a

iir-v-coprodnel membrane

the uro':a c u m which

is

the

smtiles t

cepasa ‘vo ; ont o'; Lorry from the coprodaeum by

a uro-'Ooprob'ieI se'f'T'nw r.n-l posteriorly from the nroetodneum. by isropr or my .inel. membra-.ne ,

On the ventro- U corn j. e nd uorsy~ia teral walls of

thlr. cor. x".' I..;;.,-:;;t Os - found '.ne yenit?i and uretai papi.1 lae<

Posterior

to the urcdartux is the proctodaeum which is median in

It is

s e y - . r r

s i z e .

ted anteriorly from the urodaeum by the ury~nroc touael membrane,

Posteriorly it is Limited by the walls of the anal sphincter.

Extend­

ing a'lory the inner mid-oorsai wall of this compvrI men t from its f-nterior t~> its posterior limits is found a broad fold, the anterior border
of which is covered by the uro -croctodne] fold,

2.

PAR To rdid.

Observe ti.onr made on the perbridge were made as

descrlb*.} in the preceding section.

Observations are given in tills

senhion in Plats I, Figure 3 arid Plate III, Figures i and 2.
Ventral csoec t,

It is, evident from Pie te I, Figure 3 that the

coprodaeum (b) is separator anteriorly from the roc turn (a) by a series
of lonyitudine.l folds (o; which surgest the presence of a sphincter' at
the recto-coprodaei junction (dj .

The discope,--,ranee of the folds (o)

in this are;' and the appeeranee of r.n extern;1! fold further supports
the view that a sphincter is present at this point.

1 deep pocket is

:
found aat the posterior limit of the coprodaeum.

Posterior to the

coprodaeum and separated from it by an irregular lobulated membrane, the
uro-coprodael fold (e), is the urodaeum (l).

On the mid-dorsal wall of

this compartment is found the uretal vestibule (t) in which are located
the uretal apertures.

Just lateral to the vestibule are the genital

papillae within pocket-like depressions (m and m>).

Posteriorly the

urodaeum is separated from the proctodaeum (h) by an irregular lobu­
lated membrane, the uro-proctodael fold (j).

The broad fold (i) ex­

tends along the mid-dorsal wall of the proctodaeum from the uroproctodael fold to the anal sphincter.

In the middle of this fold, the

anterior margin of which is covered by the uro-proctodael fold, is
located the aperture of the bursal canal (u).

Posteriorly the procto­

daeum is limited by the walls of the anal sphincter.
Sagittal aspect.

Plate III, Figures 1 and 2 show that the

coprodaeum (b) is separated from the rectum (a) by a slight constric­
tion, the recto-coprodael junction (d).

An oblique fold (s) arises

from the inner dorsal surface of the coprodaeum and extends ventrocaudally, terminating along the lateral wall of the compartment.

The

presence of this fold and the recto-coprodael junction suggest the pre­
sence of a sphincter.

Posteriorly the coprodaeum is separated from the

urodaeum (1) by the uro-coprodael fold (e).

On the dorsal lateral

wall of the urodaeum is the right uretal aperture located at the tip
of a fold-like papilla (f).

Ventral to this papilla and located on

the wall of the urodael chamber is the cone-shaped genital papilla
(g).

Separating the urodaeum (l) from the proctodaeum (h) is the uro-

proctodael fold (j) which is the anterior limit of the proctodael
chamber.

Posteriorly this chamber is limited by the walls of the

anal sphincter.

Entering the anterior dorsal border of the proc­

todaeum is the funnel-shaped bursal canal (q) leading from the bursa

(c).

The cavity of the bursa, at these ages, is completely filled

with well developed folds (p).
Observations made on the cloaca of the partridge show that the
coprodaeum is limited anteriorly by a recto-coprodael junction and an
oblique fold and posteriorly by a uro-coprodael membrane.

Posterior

to this chamber is the urodaeum which is limited anteriorly by the urocoprodael membrane.

Within this chamber on the dorso-lateral and ventro­

lateral walls are found the uretal and genital papillae.

Posterior to

the urodaeum and separated from it anteriorly by the uro-pi-octodael
membrane is the -proetodaeum.

Entering the anterior dorsal margin of

this chamber is a canal leading from the cavity of the bursa which at
certain ages is completely filled with folds.

3.

PHEASANT.

Observations made on the pheasant were made as

described in the preceding section.

Observations are presented in

Plate I, Figure A and Plate II, Figure 2.
Ventral aspect.

Plate I, Figure A shows that the rectum (a) is

separated from the coprodaeum (b) by a constricted area, the rectocoprodael junction (d).

The nature of the longitudinal folds in this

area suggest the presence of a sphincter.

Likewise, the coprodaeum

is separated from the urodaeum (1) by the uro-coprodael fold (e).
On the dorsal wall of the urodael chamber are the uretal apertures
(f and f ’).

These apertures are found at the anterior border of

longitudinal folds rather than on disc-shaped papillae observed in the
fowl and partridge.

The genital papillae (g and g') are just lateral

to the uretal apertures and are similar to those described for the
fowl and partridge in that they open into the chamber through pocket­
like depressions.

Posterior to the urodaeum and separated from it by

an irregular lobulated membrane, the uro-proctodael fold (j), is the
proctodaeum (h).

An obovate mucosal fold, the broad fold (i), is

found upon the dorsal wall of this chamber.

On the anterior margin of

this fold is located the aperture of the bursal canal.

Unlike the fowl

and the partridge this aperture is covered by the uro-proctodael
membrane.

Posteriorly the proctodaeum is limited by the walls of the

anal sphincter.
Dorsal aspect.

Plate II, Figure 2 shows that the rectum (a} is

separated from the coprodaeum (b) by a constriction, the rectocoprodael junction (d).

Posteriorly this compartment is separated

from the urodaeum (l) by an irregular lobulatea membrane, the urocoprodael fold (e).

On the ventro-lateral wall of this chamber are

found the cone-shaped genital papillae (g and g'} within pocket-like
depressions,

lateral to these papillae are the uretal apertures (f

and f 8) often located on small elevated mucosal folds.

Posterior to

the urodaeum and separated from it by the uro-proctodael fold, is the
proctodaeum (h).

The pouch-shaped bursa (c) is connected to the

dorsal surface of the proctodaeum (h) by means of a canal (q).
the bursa are well developed folds (p).

Within

Posteriorly the proctodaeum

is limited by the walls of the anal sphincter.
It is evident from the preceding observations that the cloaca
of the fowl, partridge and the pheasant consists of three compart­
ments.

Observations made on the individual compartments show that

the coprodaeum in the three species studied is the largest, while the
urodaeum is the smallest.

The proctodaeum is smaller than the

coprodaeum, yet larger than the urodaeum.
Observations made show that these compartments and their limits
are essentially the same in the three species studied.

The position of

J-Vi'*

n y •b, 1

.;

r:!!':

,

r'er;I tv : i

ir,; i f f . eh'-nod

o f'
t

hr.

h.r' I—

nf 1 ; no

r,

■ -r- '

,

.■■’ ■ n ' : ' i n

f

y

fowl .

^ tmli V"■’ v-:0’"o

c 'c v t 'f : J
tv o ; .i

S !tv "r ;>

f < » y

t

ten ion 1lii’i t of

it,

'■ ■ ■ ■ :'

i.-v V hi .1 d '-"3 onr;

eiir U ;.-.r in the1, '.hey
o f

th e '

" r o e t- o d r tP u r r .

I'enh .i v)!> fdlonp-

th e

V.y

rrin - cionsol.

v.’hi.ln- n o n 1? ,;o
-

■■■■" i n i r :

in

|->I. r-

't’-o

‘

"Op

non.

i

] .•r- •■1 ;

r,p;

'

fold

-n

* Vie n o r *'i ’ • ' d . r ,

th;,h the •
folds rnd

ti onn thr-i th?

the oopnodnoun;end the 'tv?,to

oV'" i - ' '■■•> O M -.j-oe .

o r hnr.;"■ riih ‘i

r'

5.!'!

f- no i i'rev 1 :'.o e•‘■rider' *• .fron’.f,hi- 'iv-eedinr- obeervr

. ;,n

O.-.r ;

1 tr- !'

e h ; ir . h e n ,

o n e ! eh the 1

’

O1

1

I i v .■'!} ne e i i r'•>f1c ''.h

v .<e o n r n - e '" '- ’d

..jr-l !

VO

none

phe

v.h v

not d.tne-nt'oyod

r, p p . T ' r !t

\fj i

g

■ i . ■ ... 1■-V.'■■•

r r,

-v >\ r ,

n

n

fo ’d

oheeean h d l f -

on

,"

th e

th e

j- .n te -

s in both, the
'i n

the

"■’ ^h:p U VO - 0

.'Vl'tl'i P O P

^OCt'"G1

B. Relation between Size and Age of the Cloaca in the Fowl
from Hatching Date to Sexual Maturity

Observations given in this section of the study will be presented
in Figures 1 and 2 and Table 1.

CLOACA,

Comparative sizes of the fowl cloaca from hatching time

to sexual maturity were observed.
Figures 1 and 2 and Table 1.
use of metal dividers.

These observations are shown in

Length measurements were obtained by

The recto-coprodael junction was used as the

anterior limit of the cloaca and the walls of the anal sphincter as
the posterior limit.

The cloaca was opened by making a longitudinal

incision along its ventral or dorsal surface.

The free edges of the

incision were then turned back and pinned to the dissection pan.
Extreme care was used in obtaining the measurements.

In those

specimens in which the recto-coprodael junction was indefinite, the
anterior limit of the coprodaeum was approximated at a point midway
between the rectum and coprodaeum.
Figure 1, Table 1, Column 5 show that the length of the male
cloaca increased from 5*8 mm in the 17 day foetus to a maximum of

41.2 mm in the 131 day fowl, decreased to 34*0 mm in the 156 day
fowl, and then remained fairly uniform in size (33 »3 mm) until the
195 th day.

Increase in length of the female cloaca, closely par­

alleled that of the male, but differed in that maximum length
(36.2 mm) in the female on the 131 st day was less than maximum
length (41.2 mm) in the male.

It is also evident in Figure 1, Table

1 that constancy of increase in length remained more uniform in the

Figure 1. length of the cloaca in the fowl.
Ordinates, length
cloaca in millimeters.
Abscissae, age in days.
, males;
females.
Figure 2. Width of the cloaca in the fowl.
Ordinates, width
cloaca, in millimeters.
Abscissae, age in days.
mad.es;
females.

2.3

Figure 2

O/

V:^I H

07 Pio FOOT CIO.A00 FH“>b
!:.■ TP;iTj.i“ iiiiv r<i 05:>t .
m
;.brn.n,i i'Y

'rn;:

1

1
V P
in
iv y

17 /i-.T r-~
1
7

Fair

SO
OJ'
.
..
CO
101
1?1
!c£
195

17 d£./ foetus
1
■■ ■
■ ■ -

Female

SO
31
59
101
131
156
195

i

Firc-ir
rue Fl'iect
j941

Our. t.<-'jof
Specim.ora'-

21-!m:h ry
,!■'neery
T'.m*?
February
February
Felr u ary
iuy,-F-ppt ,
3?pt ■■-Nov
November
September

4
1.1
13
10
10
10
6
r.
>
6
4

January
January.
January
February
Februn ry
February
buySept.
Sept.-Nov.
Noven- her
Sent.ember

r

c

\ tn*.'rrp
C-irrO

b:i0 !b
(mm)

5 .a
10.6
1y _0
15.S
1 7 .Q
0] .6
35.7
41.0
34.0
33.3

740
H/
...1 1 . ,... ..., ,13.6 ....13
17.S
10
15.0
13
16.4
12.1
10
ib
32.1
po. 2
5
36,2
7
0
34.2

~ 0
4.3
5.0
6.0
f S-,
c .P
a ,7
11.3
11.a
12.2
1 0 .0

2,4
■4 .4 '
5.4
6.0
6.3
C
0*.I/t
1] .1
12.3
11.2
12.3

female from the131 st

day (36.2 mm) to

it was in the maleover the same

period

the 195 th day (34.8 mm) than
of time.

The variations in

length of the cloaca, between the 7 and 20 day chick are probably not
significant.
Further analysis of these results show that the percentage in­
crease ofcloacal length in the male
to the 59

was 272„4 from the 17 day foetus

day fowl while from the 59

day fowl to the131 day fowl, the

age at which maximum length was attained, percentage increase decreased
to 90.7.
was 23*7.

Following the 131 st day the percentage decrease in length
likewise in the female the percentage increase of cloacal

length from the

17day foetus to the 59

the 59 day fowl

tothe131 day fowl,

day fowl was 215.7 while from

theage at which maximum length

was attained, the percentage increase decreased to 63.8.

In the

period between 131 days and 195 days the percentage decrease in
length of the cloaca was 4..C,
It is evident from these results that percentage increase in
length of

the cloaca in the male was

from hatching

greater than itwas in the female

date- until- a--maximum was reached' (41*2mm).

However,

the percentage decrease in length of the cloaca was less in the female
after the maximum was reached than in the male.
Figure 2, Table 1, Column 6 show that the width of the cloaca
in the male increased from 2.2 mm in the 17 day foetus to a maximum
of 12.2 rcrc in the 156 day fowl and then decreased to 10.0 mm at the
195 th day, which is probably not significant.

Increase in width of

the female cloaca closely paralleled that of the male but differed
in that the maximum' width of the cloaca, was reached on the 131 st.
day and remained fairly constant until sexual maturity.

The small

variations shown between the 131 st and the 156 th day are probably

not significant and depend on (l) paucity of observations, and (2)
unavoidable inaccuracies in the method used.
Further analysis of these results show that the percentage in­
crease in width of the male cloaca was 295,4. from the 17 nay foetus to
the 59 th day while from the 59 th to the 1$6 th day, when the maximum
was reached, the percentage increase in width decreased to 4.0.2.
Further study of Figure 2 and Table 1 will show that the percentage
increase in cloacal width in the female closely paralleled that of the
male.
It is evident from these results that the male shows a greater
increase in percentage growth in size of the cloaca than the female
and that maximum size in both sexes is attained from the 131 jst day
to the 156 th day.

Size of the cloaca from the 156 th day to sexual

maturity remains fairly constant in both sexes.

C.
Relation between Sise and Age
of the Coprodaeum, Urodaeum ana Proctodaeum
in the Fowl from Hatching Date to Sexual Maturity

Observations made on the coprodaeum, urodaeum and proctodaeum an
presented in Figures 3-8 inclusive and Table 2.
Coprodaenm.

In making the .Length observations,

the recto-

coprodael junction was used as the anterior limit while the urocoprodael fold was used as the posterior limit.

In observations on

width the walls of the coprodaeum were used as the lateral limits.
Mean widths at the recto-coprodael junction (narrowest limit) and at
the uro-coprodael fold (widest limit) were averaged giving a value
thy t, represented the mean width of the compartment.

Results given in Figure 3 and Table 2 Column 4 will show that
the length of the male coprodaeum Increased from 3-3 mm in the 17
day foetus to 11.9 mm in the 7 day chick, decreased to 10.4 mm in
the 20 day chick, and then increased to a maximum of 26.3 mm on the
131. st day.

Following the 131, st day... the. length decreased to 19.8

mm in the 195 day fowl.
Further analysis of these data will show that the percentage
increase in length of the coprodaeum of the male reached 260.6 from
the 17 day foetus to the 7 day chick, decreased to 14-4 between the
7 and 20 days, then increased again to 152.9 between the 20 th and
131 st day.
day.

Maximum length of 26,3 nun was reached on the 131 st

It is evident from further study of Figure 3 and Table 2

Column 4 that the percentage increase in length of the coprodaeum
in the female parallels fairly closely that of the male.
Figure 4, Table 2 Column 5 show that the width of the male

Figure 3,. Length of coprodaeum in the fowl. Ordinates, length
_____ , maleaj - - - _
in millimeters. Abscissae, age in days.
f erca 1 e s ,
Figure ,
4.
in mi]lime ter s.
f emale s ,

Width of coprodaeum in the fowl. Ordinates, width
Abscissae, age in days.
_____ , males; - - - -

Figure 3

TABLE 2

SlZH OF CO
HAfC

Brt'fMEM'S OF THE FOV1 C10ACA
>jG DA f'Fi TO SEXUAL 71 TUB ITE

Columns
o'
s

Sex

Age
in Days
17 dav foetus

i
Male

7
20
32
59
101
131
156

day foetus
1
7
20
32
59
101
131
156

5

Number of
Specimens

8

11
13
10
12
10

■

6
5
6

4
11
11
IQ
13
10
i6
5
7

■

Coor
Length
fTjyr^
•r„-=*5^=t=
3.3
9.3
11.9
10.4
11.2
14.0
23.8
26.3
21.8
19-8

4*4
9.2
12,3
9.8
9-8
13.7
22.3
23.0
24.6
20.6

SUIT

Width

6

7
Urodaeum
Length
Aidth
(ran}
„I i 2lL

8
9
?roc todc-eum
Length
(e e I___

7.3
7.7
8.8
7.0
8.6

3.0
4.0
4-6
4.9
4.7
4.5

2,9
3.8
4!
f.•m
w
6.0
6.5
9.1
12.8
13.6
12,0
12,4

1.0
2,3
3-5
4.6
4-2
5.1
7.5
7.2
7,7
6.8

X *^
4,1
5*2
5.1
5.4
6,7
3.5
9.4
9.5
9.1

1.3
1.7
2.0
2 •Q/
6
2.9
4.2
4*7
4,9
4,9
7,6

3.0
4,1
4.9
6.3
7.0
9.3
12’.c
13.3
11,6
15.8

1.4
2.5
3.1
3.7
4.5
,5,1
7.1
7.4
7.4
9.6

1.5
A .P

5.5
5.7
£; zr

1.2
1.6
2.0
0 c/
S-*

2.8
4*7
5-4
6.9
7.3
11.1

13.5
15.8
12.5

10.8

3,2
5.1
6.9
7.4
8.1
11.2
13.7
16.4
13-4
14.9

coprodaeum increases rapidly from 1.5 mm in the 17 day foetus to

5.5 rmr in the 7 day chick then increases slowly to reach a maximum
width ol S.cj nun on tne lol st aay after which the width remains fairly
constant tnrougn the 195 tn day.

The slight decrease in width on the

156 th day is probably not significant.
Comparison of the data given in the above figure and table shows
that width of the female coprodaeum is approximately equal to that of
the male 0:1 the 72 nd day and that the width in the female is greater
than in the male from this date until the 195 th day.
Further analysis of these data will show that the percentage
increase in width of the male coprodaeum from the 17 day foetus to
the 7 day chick was 266.6 and that from the 7 th day to the 195 th
day, when maximum width was reached, it decreased from 2b6.6 to 60.0 .
It is evident from further study of Figure 4 snd Table 2 Column 5
that percentage increase in width of the coprodaeum in the female
c lo s e ly

parallels that of the male from hatching date through sexual

maturi ty.
Transposition of the data obtained for length and width of .the.
coprodaeum at various ages to growth makes it apparent that growth
increases rapidly from hatching date to the 7 th day, and then it
remained fairly constant until a maximum was reached on the 131 st
day.

The decreased length and width of the coprodaeum on the 156

th day is probably not significant as observations were recorded for
only six birds.
Urodaeum.

In measuring the length of the urodaeum, the uro-

coprodael fold was considered as the anterior limit while the uroproctodael fold was taken as the posterior limit.

In measuring the

width of the urodaeum, the inner walls of the compartment were con~

sidered as the lateral limit*.

Results are presented in Figures 5

and 6 and Table 2 Columns 6 and 7.
Figure 5, Table 2 Column 6 show that the length of the urodaeum
in both male and female closely parallel each other until the 131 st
day.

The female urodaeum then increases rapidly to a maximum of 7.6

mm on the 195 th day while the length of the urodaeum in the male
reaches the maximum of 2-9 mm on the 131 st day and remains ra ther­
eon 3 ton t in size (2-5 mm)

through the 195 th day.

It is evident that

the increase in length from 1.2 mm in the 17 day foetus to & maximum
of 2.9

mm in the 131 day male is gradual and that the

fairly

constant from this age through the 195 th day.

lengthremains

In comparing the percentage increase it can be seen that in
the male from the 17 day foetus to the 59 th day, the percentage in­
crease was 233*3 while in the female for the same period the increase
was 223.1.

From the 59 th to the 195 th day percentage increase

in the male reached only 12.5 as compared to 81.0 in the female.
These results make it evident that percentage increase in
length of the urodaeum, was essentially alike in both.sexes until the
59 th day and then percentage
to the

increase in length from

the 59th day

195 _th day was greater in the female (81.0) than it was in

the male (12.5).
A comparison of the data given in Figure 1 and Table 1 with the
data given in Figures 5 and 6 and Table 2 shows that the increased
length of the female cloaca in fowl between the ages of 156 days and
195 days is due primarily to the increase in length of the urodaeum.
It was brought out in the preceding pages that the length of the
coprodaeum remained fairly constant between the 156 th and 195 th
days.

_

Figure 5. Length of the urodecum in the fowl.
Ordinates, length
in millimeters.
Abscissae, o,<:e in days.
, males;
females.
Figure 6.
i n mi 11 lireters.

females.

Fidi.h of tho urodaeum in the fowl.
Ordinates, width
Abscissae, a r e in d a y s , m ales;

€

4

J

P * >6 JO je « js «C ,s

,5

,,g /£g•(Jg

^ M /7f_ /9(.

/4t?* in Days

Figure 5

/

*'S .'

46

tf«

f*
/4j># /»»

/Of
Days

Figure 6

iis

'*€

/46

/<»* /ap

">r

Figure 6, Table 2 Column 7 show that the width of the urodaeum
in the male increased from 2.9 mm in the 17 day foetus to a maximum
of 13.6 mm on the 131 st day and remained fairly constant in width
through the 195 th day.

Further analysis of these data will show

that the percentage increase in width in the male was 369.7 from the
17 day foetus until the maximum was reached on the 131 st, day after
which a percentage decrease of 9.8 was recorded from the 131 st day
to the 195 th day.

It is evident from the data given in the above

figure and table that the percentage increase in width of the female
urodaeum closely parallels that of the male through

the 131 st day,

but in the female, percentage increase in width waswpshpr
from the 131 st day until the 195 _th day than it was in the male
(9«3) in the same period.
Proctodaeum.

In measuring the length of the proctodaeum the

uro-pro.c todael fold was considered as the anterior limit while the
inner walls of the anal sphincter were considered as the posterior
limit.

Results are presented in Figures 7 ana 8 and Table 2,

Figure 7, Table 2 Column 8 show. „tha,t the length of .the proctor
daeum in the male rapidly increased from 1.0 mm in the 17 day foetus
to 3.5 mm in the 7 day chick, slowly increased to a maximum of 7.5
mm on the 101 st day and then remained fairly constant through the
195 th day.

The decrease in length recorded for the 195 th day is

probably not significant and would undoubtedly approximate the
length recorded for the F L st day fowl if observations were made on
a greater number of birds.
Further analysis of this data will show that the percentage
Increase In length of the male proctodaeum increased 250.0 from the
17 day foetus to the 7 day chick then decreased to 11/+.3 at the

Figure 7, Length of the proctodaeum in the fowl-,
length in millimeters - Abscissae, age in days.
—
— f'ppi',’P ,Q
Figure 3, Vvidth of the proctodreum in the fowl.
width in millimeters, abscissae, age in days.

Ordinates,
, males;

Ordinates,
, males;

/

/4*

Figure 7

Figure 8

/fie

ise

/ste

101 s_t day, the age at which maximum length was reached.

Further study

of the above ligure ano table will show that the percentage increase
in length of the proctodaeum ox the female closely parallels that in
the male to the lp6 th day and then percentage increase in length is
greater in the female than it is in the male from the 1$6 _th day to
the 195 .th day.
Figure 3, Table 2 Column 9 show that the width of the male proc­
todaeum increased from

2.3 mm inthe 17 day foetus to a maximum of

1.5-3 mm in the 131 day

fowl thendecreased

to 10.3mm on the 195 th

day.
Further analysis of these results will show that the percentage
increase in width of the proctodaeum in the male was 4.64.3 from' hatch­
ing date until maximum width was reached (131 days) and then decreased
to 46.3 at the 195 tlx day.

It is evident from the above figure and

table that percentage increase in the female is fairly closely corre­
lated with that of the male from hatching date to sexual maturity.
Transposition of the data obtained for length and width of the procto­
daeum at various ages to ,growth shows that growth in ,length is
similar in the male and female from hatching date through the 156 th
day, and that growth is accelerated to a greater degree in the female
between days 156 and 195 than it is in the male in the same period.

CLOACAL PAPILLAE.

Specificattentionwas paid to size of the

uretal and genital papillae which were located on the dorso-lfiteral
and ver.tro-lateral walls of the urodaeum (l), (Plate III, Figure 4)*
Observations given in this section were made by the use of metal
dividers and a standard white celluloid millimeter rule.
tions made are presented in Tables 3 and 4«

Observa­

39

a. Uretal papillae.

Table 3, Columns 3 and U demonstrate that

the mean height and width of the uretal papillae in the male and fenv-ls iemained faiily constant from n&tcning date through sexual
maturity, and that there was no significant increase in growth durin^
this time in either the male or female.
b. Genital papillae.

Table 4 Column d shows that the height

of the genital papillae in the male increased from 0.5 mm in the 17
day foetus to a maximum of 3-7 mm in the 131 day fowl and then re­
mained fairly constant through the 195 th day.

The variation follow­

ing the maximum at 131 days are probably not significant.
Further analysis of the preceding data shows that the percentage
increase in height of the genital papillae in the male was 64.O.O
from hatching date until the maximum was reached (131 days), after
which the percentage decrease was 15*6 which is probably not signi­
ficant.

It is evident from Table U Column U that the per­

centage increase in height of genital papillae in the female
closely parallels that of the male through the 32 nd day after
which the male shows a greater increase than the female until the
maximum on the 131 st. day.

Following the 131 st day the female

showed a rapid atrophization of the papillae.

Further study of

Table /+ Columns 5 and 6 made it apparent that the widths and thick­
nesses of the genital papillae in the male and female closely
parallel the increase in height.
Comparison of the results given in the preceding paragraph
make it evident that increase in growth of the genital papillae when
measured by percentage increase is fairly similar in the male and
female from the date of hatching through the 32 nd day after which
the male showed a greater increase until the maximum is reached on

TABLE

MEAN HEIGHTS AND vTiDPHS OF UKETAI. PAPILLAE IN THE
FOV1 FROM HATCHING DATE TO SEXUAL MATURITY

Columns

/

Age

in

D a y s

N u m b e r

3

of

S o o n i.mens

d a y

f o e t u s

H e i r h i

Yvidt

fmrn'

(.-nrr.;

12

0 . 4
0
r
W *

0 .

10

20

0.5

1 .

"Jo -'-Z'

25

0.5

59

20

I «0

0 „

V)1 V.' o

!

1 .
ff

0 .

1 0 1

??

0.5

0 .

131

10

0.5

0 .

I f E

13

195

13

—

0 .

—

0 .

OW

17

4

VjJ

1

Several specimens in which the apertures sere unusually
wide.
The males gave unusually high measurements,.
No definite papillae could be observed.

TABLE 4

SIZE OF GENITAL PAPILLAE IN THE FOWL
F90K HATCHING DATE TO SEXUAL MATURITY

Columns

1.

*.

Ape
in
Pay s

Sex

0
J

4

5

6

Height
(mm)

Width
(mm)

Thickness
(mm )

0.4,
0.4
0.6
0.9

0.2
0.3

0.9
1.3
1.6
1.9
1.6

1.4
1.5

1 .8

1 .1

Number

of
Specimens

Hr* ,i__ (\ i
j_/ U<r/y iOtjLUa
1
7
20

13
10

U*5
0.6
0.8
1.1

3?
59
101
131
156
195

12
10
6
5
6
4

1«^
2.0
2.8
3.7
2.8
3.2

17 da.y foetus
"1
7
20

4
;I
ii
10

0.4
0.5
0.9
1.0

X-'
59
101.
131
156
195

13
10
16
5
7
9

0.9
1.2
1.6
2.0
1.7

a
Ix

...

0.4

Male

'

'

.

n
0.5
0.6
0.8

0.5
l.C
1 .0

. - 0 *2 .
0,3
0.3
0.4

Female
0.9
1.2
1,3
1..6
1.5
‘rr

___ Data not taken.

~a-

Only three specimens showed presence of papillae; they
averaged 2.1 mm in length, ()„9 mm in width, and 0, 8 mm
in thickness.

0,5
0,8
0.8
1.0
0,9
•H'

U2

the 131 st day.
The variation in height, width and thickness of the genital

papillae in the male following the 131 s_k day is probably not
significant for the following reasons:

(l) too few observations

made, and (?.) method used allows for greater variations.

In the

female a rapid decrease in growth occurred following the maximum
at 131 days through the 195 th day.

It is also evident from the

preceding results that the genital papillae in the male reached
a greater sise than the female from hatching date to sexual
maturity.

r

D.

tl

:\ e

t. i i f i

iv

p sr/vvocn

l i n o an d
o f th e
SO!?. J. f’ l'i.liH ! if; i f •'! I ryi id: !

i:i«

V*

ere

lu r e
i.e ? >3ft i

i-hc,

p. r e s ent or i

try

in

> ~,'r

pj

9-1?

• ' !’1■
■ ‘. _ - :l e L''i'??'■■!

i'P, o . r*

'-.iii

*1 t

r( !’V:j U.?.■o vvr,r, ?>■’’ Prow y/7 mfr, ■;,, h .
?d

rou* :■!

n a e c re rs e

th

rre '''

i

.....''1,,! . J

•i' e: n.-y?

. i r;h ' t c o n t i n u e s
it

*

t;_
■|r

;'

to i r e
:,r r

r .n e

i? ' ' y

*"

■i ’

i.M fj

’ r

*■

t of the .to in through the

i

I ’<

I.-,

f*0 *?n ~

5/ th Cay a cfyn*?

re in Iength, tut the merlm'im of
. day m d

1 'i

:-

then it decreases to

is

11.5 mm on

ie 1°5 th dry.
Pur t h y

a n a ly s i. s

of t h e o r f t c e d in y r e s u l t s

ohov,n

th a t th e

esr--

ceutyyo increase in. ieog.tri of -t.iie --bursa •in-- the -male was-355 *5- from"
the

17 day f‘oetos until the

fhis f a i r l y
”j t-]

i

f~ *}-)

y y r}

(q

rr.?t:d mum aas rencbed on the 59 t h

day.

rapid increase to a maximum was followed by a deorerso
|)0 7 -> Q p n

T,h C^O-

H a; c; i

^

' 9

^

i' u.? V-- T r* y»r, tin -"‘i,' l v'; ^ n ~l-rsSG 1*1 1.0

O

t-h of*

il

y ,} lf- ;

th V

c>

*1 1 "i

n

t; t '

T v j

t, 'I * - 1

^

P

’ ■'XV S?•.. W>~ S 473 * 3 f I'CMI- tfV?

17 ha/ foetus until the mfiv.i'nuir. van/ rencheti on the T31 st aayt then
as vva s !,ho c-:,s« in the rale,

the l.enyth decreaeea.

Hie ue/'oen tage

-s...crease WK5 ?33,o from the ’!31 at day unt.i.the 195 Jth day,
T t is

p e n c e I v a b le

le n g t h

of

in

fetr.ce.le

th e

th e b urs*?

fr o m

(it,/;

tdur* l e n g t h

th e

mm)

PT’e c e o in y

r e s u !. i-s

is* rer-.cheri in .

g r a d u a lly

in c r ia s s d

tb a t niaoci.murn

th e ma ^ ? i.n 59 o.ays *yhxl.
to

re s .c n a rnai.ir.urn o f

/!

F 1 !'*u i •e 9 * I e ng t h o f ! .11e b u r s a
a r b u r s a i n r.;i 1 ! Irre t e r n .
/>bse >

>

i n th e f o w l ,
O rd in a te s ,
t i f t 5 i n ciJLvs *
—
l_>

«/

b u rn t. Li! t h e f o ' w i .
1 .=s a e , age i n d a y s .

le n g th
„ jpr; >
j*

*” -

-• y

O r d in w t e s , w i d t h
, m a le s ;

•

*•> ^

fthuki

figure

Figure 10

TABLE 5

SI7-F AND WEIGHT OF TH? BUFSt IF THE FOWL
FROM HITCHING Df TF TO SFXUil M/.f[]RITY
Columns

1

3

Are
3f:y

Msle

in levs

?2onth
Specimen Silled
1921 :

17 any foetus
1
7
20
32
59
101
131
156
195

January
January
Jb nunry
February
February
February
Aug.-Sspt.
Sept.-Nov,'
November
September

17 day foetus
1

January
January
January
February
February
Petrusry
buy.-Sept.
Sept.-Nov..
November
September :

r!-

bemele

■
.

20
32
59
101
131
156
195

4
Dumber of
Specimens

rS
O
11
13
10
12
10
A
5
6
4
*/+
11
13.
10
13
10
16
c
>

ni

9

5

6

Length
t'.icith
(mm)
. . . >.n.) _ _
/r“n»
-

F»9
11,9
13..6
15.6
21.4
21 .4
15.3
U.7
11.0
4«5
7.6
9.9
13.0
15.0
21. C
22.S
26.8
23.9
11,5

2 .8
5-2
7,3.
10,1
11 .V
17.3
16.0
If .4

13,3
ul, j
5-5
6 ,n
9 5
10.7
16.2
20.7
44 •4
19.0
9-5

7
Thick­
ness (ir.my

8
Weight
... & e 1.

2.0
2.9
4.4
3.0
10.0
14.0
10.3
9.8
8.8
5.2

43,3
114-9
497.3
76.1,1
2189,1
1530.8
1821.0
344.5

1.7
2-5
4.1
7.0
9,2
11.8
16,6
17-0
13.6
7.8

14-0
35-0
65-5
337,4
759-1
1823*4
3406.6
4827.4
3306.0
568,6

12.6

Data given in Figures 10-12 inclusive and Table 5 Columns 6-8
inclusive likewise show that the width, thickness and weight of the
bursa reaches a maximum on the 59 th day in the male and the de­
creases slowly to a vestige on the 195 th day.

In the female the

width, thickness snd weight of the bursa increases slowly to reach a
maximum on the 131 st day then decreases rapidly to a vestigial struc­
ture on the 195 th day, i.e., it is apparent in the above figures and
t a l — uii‘j t uiie aeci ec;.oe In leii^oh, 'aIul-xi, tiiicmness auu weight was
gradual in the male and fairly rapid in the female, i.e., the weight
of the bursa in the male reached 2189*1 mg on the 59 th day then
slowly decreased to 232.0 mg on the 195 th day.

However, in the fe­

male the weight of the bursa rapidly increased to a maximum of 4-827.4.
mg on the 131 s_t day and then decreased to 568.6 mg on the 195 th
day.
It is evident with the data given in the preceding paragraphs
that the bursa reaches a maximum on the 59 th day in the male and
on the 131 st day in the female, then decreases in .both sexes to a
vestige at sexual maturity.

Jolly (1915) found that in the fowl the

bursa reached its complete development at the beginning of 150 days
while Riddle (1928) found that in doves and pigeons maximum bursal
size was attained from 69 to 75 days of age.
Comparison of the Figures 9-12 inclusive and Table 5 with
Figures 14-17 inclusive and Table 8 make it perceivable that the
gonads are undeveloped a.t 59 days while the bursa has reached or
is attaining maximum development and that sexual maturity is at­
tained following atrophization of the bursa.
in agreement with those of Riddle.

These observations are

the burse in the fowl. Ordinates
m s . Abscissae, asre in days *

49

Fem

t?00

Figure 12

The preceding results show that there is a correlation between
bursal atrophization and sexual maturity in the fowl,.

Jolly (1913)

suggested that the bursa prepared a hormone-like substance which
suppreosed post-natal development 01 the gonads.

Riddle thought his

observations supplied some evidence for such a relationship.

He also

thought that the follicular hormone (FSB.) from the anterior pituitary
exercised a xe Larding action on the testes in post—natal stages.

In

1933 ridage supplemented this theory by presenting evidence that ex­
cess amounts of prol«actin from the anterior pituitary suppressed
gonadial growth.
On the basis of Riddle’s observations and the results presented
in this study it appears probable that gonadial development is re­
tarded in cost-natal ages by an excess of prolactin until maximum
bursal growth is attained, after which the amount of prolactin se­
creted bv the anterior pituitary decreases allowing rapid gonadial
development to occur.
Bursal folds.

Figure 13, Table 6 Column 4 show that the number

of. bui'sal folds in.. the. male increased from 15 in the 17 day foetus
to 16 in the 20 day chick, then remained fairly constant through the
131 _st day and decreased to 11 at the 156 th day.

The variation

in number of folds in the 1 st and 7 th days is probably not signi­
ficant.

Following the 156 th day through sexual maturity (195

days) the bursal folds atrophy rapidly.

It is evident from further

study of the above figure and table that the number of bursal folds
in the female fairly closely parallel those of the male.
The preceding results make it apparent that there is no sig­
nificant increase in number of bursal folds in either the male or
female fowl from the hatching date to the 156 th cay, after which

TABLE 6

OT. OS IM THE BUREA OF THi

FROM H/TGHINO

pa

rr; ru

ee .x [ ia i .

:

EOEL
■T

P y

Cel u;ryiG

A HCCl'nens
L? vii y foetus
]
7
PO
37

Male

jrn
,

101
133
156
105

1.7 dt-.v foetus
■. rj- . -.

20
*
1;
Feir.n.\& .1
j
59
101
131
156
195

■

8
11
]3
"!0
10
10
6
0
j
h)
)
*-+•

4
11

11 '
10

oC
idrjy-“p ]_
F o ld s

15
is
10
16
13
\ ,*
15

"
1

11.
■■

11
13
13 " '''
16

1-u

U

10
16

14
16

15
7
9

lb

Only two specimens showedi folds (averaged
3 fol r- *
Only one speei men showed fold n (trvree folds).

Lnere ib rapid atrophination of the folds through sexual maturity.
Text, Table 7 Column 4 shows that the width of
the bursal canal in the male increased from 0.6 mm in the 17 day
foetus to a maximum of 1.9 rcra in the 7 day chick and then remained
constant tnrough the 101 s_t day, after which it decreased to a mini­
mum of 0.5 mm nt the 19? th day.

The decrease in width following the

is probably not significant for the following reasons;
(1) pruci ty of observations and (2) unavoidable inaccuracies in the
meLnoo used.

Li-cewi.se in the female, the width of the bursal canal

increased from 0.5 mm in the 17 day foetus to a maximum of 2.5 mm in
the 101 day fowl, then deci’eased to 0.9 aua in the 195 day fowl.
Further analysis of these results demonstrate that the percen­
tage increase .in width of the bursal canal in the male was 216,7 from
the 17 day foetus until the maximum was reached at the 7 th day,
after which the width remained constant through the 101 _st day.
From the 101 £t day to the 195 th day the percentage decrease was
280.0.

In the female the percentage increase in width of the bursal

canal was 4-00.0 from the 17 day foetus to the 101 st day, -the age at'
which maximum width was reached.

In the period between the 101 st,

and 195 th day the width of the bursal canal decreased and when cal­
culated on a percentage basis it was found to be 177.8.
The preceding results make it perceivable that the male reaches
maximum width of the bursal canal at an earlier a.ge than the female,
while in the female,bursal canal width does not reach a maximum until
the 101 st day; in the former the greatest siae reached is 1.9 mm
end in the latter it is 2,5 mm.
It is evident from the results shown in the preceding para­
graphs that the increase in growth of the bursa parallels fairly

PA RLE 7

WIDTH OF PURSAf. c a m a i in t h e f o w l f r o m
HATCHING DAT! TO SEXUAL M/\ PUfiHY

Col umns

Width of

Number nr
Oreo i:usr?.s
1*7
1 <
]

o',-v,
-a ,-v

r n p h ! : :
- ° ^

Bur.S’-l C ^ n l
(mm'
0 . 6
■]

-1 L

i

*~7
1 - 9
V*h
1 0
j>/

i . 9

1 1

U~)

1 * 9

.1 0

1 . 3

1 0 1

6

1 . 9

0 -5!

r

i

,A

o

_ w.

0

„ 5

'j r\ 1

6
/
"4

1 C( r'

'
1 7
1

{
'1 :
o o

dr;;/

f V - L i i *
1 1
1

1 , 2

•;

1 0

13
1 Q

5 9
1 0 1

16

1 5 1

5

, 2 . 1
'

1,7
1.7

1..1
2 . 5
?

I
* H-

1 5 0

n

n

o

9 Q c

q

0 , 9

closely that of the hursal canal while the naraber of bursal folds
appear to be independent of bursal size and weight until the 156 th
day, after which decreased growth in the bursa closely parallels de­
crease in number of bursal folds through sexual maturity.

Re l.n fcion be txr<ren
b 17.o ''--Hu -Ar.0 of-'
Gorihds
in the Fowl from Hatching Late to Sexual Maturity

Observe lions given jn this section were made as described in the
prec'3’
.;-a;- .r.ges.

Observations made on the gonads, and the season of

r ft whi eh M r e observations were made, are given in rabies

rnd ? arf Figures if -ll7 inclusive.
'~~-

--vl) -‘j.;.'on; ig and If,hie a Coiurn f shows 1ha t the

i'^h it n‘" t!i° i">r't goi-v-d -In the male increased from g,3 mm in the 1?
dav !npt.aa

a y-. ivmur: o:

vs the aCo. ua,y fori, r\ ter whicn it

uecre'.son to a: rnen'an a-ini.mum'of 17.0 mm on the 156 th guy then it
inc^oased to a second maximum of .:2.5 mn: on the 195 th day.

In the

female the length of the left gonad increased from &.,/*. mm in the 17
day foetus to a maximum of iy.8 mm in the 1.11 dry fowl and then it de~~
ever.seti to 19.1 mm in the 156 day fowl.

fur ther analysis of these results shows that percentage in­

crease ..in••Lengthsof' the- left- mal-e gonad is lld.S between 'the 17 day'. '
foe ton •ad t>i*~ 59 dry fowl, while percentage increase in length is

II5 .O in the rm:t f2 days,
was reached.

the age at which maximum gonaai&i length

In the female, percentage increase in length is 115»3

between the 17 day foetus and the 59 day fowl, while the percentage

increase in length is 26.1 in the next 72 days, the age at which
maximum Isnxth of the gonad is a ttainea.

The percentage increase

in 1a w t h of the wight gonad of the male closely parallels that of

the left gonad.

Other results given in Figures 15 and 16 and Table

8 Columns 7 and 9 show that increases in wioth and thickness of the
left gonad in both rale and female cLose!y parallel the increases

Figure l /:- T ength of the jonaas in the fowl..
in mi.H i me tens, Abscissae, age in days,
_
right, male:’; - - - -, left, females.
F5
..t!'*re 1.5.
i n millimeter,:,.
riphI,, wiles;

hi-.if,h of the gonads in the fowl.
Abse Lssr.e, age in d a y s .

Ordinates, length
left,

Ordinates, wioth
, left. - - ~

1

fM
j/'s
Leff— Farr-o/ti

30

■*€

J~6

6b

7b

90

a6

>06

HC

/^6

'Jo

Aye /» Pays
Figure 14

•S-?A Ac.

•?6

Jb

40

S4

64

96
9b
/P6
Age in Days

<16

/JO

Figure 15
I

/46

IF/.

.'60

/?(.

/Ho

FA Dtp 3

SIZE AND iiVKlCHF OK THE FOWL CONADS
FROM 1H/ rCHlNO DATE TO SEXUAL DA PlIDII'Y

CoiUTuJ

')

1

3

*/4
.

>

6

I.enytb
.Aofith S os ci­ Aum 1er
/ ;~e
of
ne n Xj 1led
5.n
(r<in)
_Jsnocimsng left Riyht
Sex_ . . 9'ru
17 day
8
Doebus Jc nufc ry
’ 4-3
0 >3
L .1
i
January
Li
: 1.9
a;,7
6 *3
7
13
January
30
6 r,
DO
February
7.1
ri'
1
'
/
.../.
February
3?
•3
7.6
1
'
j
10.7
10
February
•9
59
9,
A
23 .0 ' ’
Aiip.-Sept,
Vale
101
*
0
El .2 9..
Sept, -Dos'.
131
156
6
November
17.0 13 *c
>
September
X
22.2_ 35 .8
195
17 dr.y
6.4 --Foe L is January
4
4 J-;
■ 6.5
1
Ja n u? ry
11
7
. 8.6 — 11
Janu;-. ry
r; L'
DO
10
February
00.9
-"
1.2.7
3 ,8
February
13
.1
Feme"
1e 59
LG
14
February
15.7
L01
16
16.9
Auy. -Sept.
-- Sept.-Mov.
5
19.3
131
'•IrVT'y?r!V.^r^
19,.! 7
156
1
nrlv r'-e
Sep terbsr
/
■■oe
,s
o-7; ry
Don; ■
; not Slcrtifi ec.*
_______

H
1

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left ■ij.-.s—AAy
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^I
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1:.6
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y
9.5
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11.8
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e 1:
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3.6
9
p .8
.i.
!1.21

_________

--

1 ■>
! u.
!.6
- .9

--

1
* I!ebllO' Lrnir;
__Leff <ra.;s.2 i
hst
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v=
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) .0
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11

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0 .9
0 ./
11

1.8

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■J*4

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40. A
44,,3

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r;
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9 •n :149.7
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7. 6
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f
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A

to
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144-7
343-3
574.4
494.9
me

ovn ry

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77.3
i9'//. 7
pi; ,p
473.3
:/.";.o
-— ...

5.0
/,1-9 *M
--

Figure 16,
Thickness of the gonads in the fowl. Ordinates, thick­
ness in millimeters.
Absnissse, ere in days.
_
, left,
- - - — , ri ’
“ht, m a l e s ;
, left, females.
rr-irure 17. H e i g h t of the gonads in the fowl.
Or dine tes, weigh i
in milligrams.
Abscissae, ate in days,
,l e f t , ____ _____ , right
mslesj _________ , left, females.

/

-

Auy.
/

/

^5 e ^/

/

'

/

/

/

/

-N o *

...

/'

/

/

Matur*s Orory Av»|
N»r.On J

^

-MtS

/ivy~5*y7^-

4

J

£

3b

46

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6€

76

86

36

106

in D»y3

116

1*4 ' 13f

1*6

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/66

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186

196

Figure 16

$
£/aoo

(0rary

loo

Agt m Days
Figure 17

,2g-

fro*, h,rm „*)

tef+Jfeyna/ms

OJ

observed ir, gonad :i.s.] length.

It is evident from these results that

percentage increase in length of the gonad is fairly similar in both
the male and female from the 17 day foetus to the 59 day fowl and
that, the percentage increase in length is greater in the male than
in the female from the 59 day fowl until a maximum length is reached.
Figure 14 end Table 3 also demonstrate that the left gonad of
the male after reaching a maximum length of 23.0 mm in lug.-Sept.,
decreases to 1.7.0 mm in November.

In gonads collected from birds

during the previous September mean length of the gonad again reached
22.5 mm.

length of the right male gonad paralleled that of the left,

although the mean length of the right reached 25.3 mm in September.
In the female the length of the right gonad fairly closely paralleled
that, of the left up to the 59 th day, after which time it decreased
to a vestige.
Figure 17 and fable 3 Columns 11 and 12 snow that the weight
of the left male gonad progressively increased to a maximum
(1546.7 mg) in Aug.-Sept. (101 days of age) and then decreased to

520.Q mg in-November (I56' days -of age). •'In'*the preceding September
gonads collected from birds again increased to a maximum of 2233.8
mg (195 days of age).

These observations indicate that two factors

are important in deterrcining weight of the male gonad, i.e., (l)
age of the bird and (2) seasonal variations.

The relation of size

to seasons has been studied by Bissonnette (1930).

He finds that

the major factor operating in producing observed changes in testes
is the increased day-length, thus agreeing with Rowan (1931) in his
work on juncos.
/ conraarison of the data given in Table 8 with that given in

64

lY.-U^e 1. su^«SmS that the size of the male cloaca is fairly inde­
pendent. of gonad size after the cloaca reaches maximum length and
wi.1th•

T.ikewioe, clodcfi.1 size in tne xeniaie seems to be independent

ot. tne variations m

size of the gonads, after the maximum is at­

tained, i.e., tne maximum mean length of the cloaca in the 131 day
female is 36,1 mm and the maximum mean weight of the left ovary is
57o.6 mg.

In the fowl of I50 days, the maximum lean length of the

cloaca is 36.2 mm while the maximum mean weight of the ovaries in thi
age group is 696.9 mg.
length of 34*3 mm.

In the mature female the cloaca has a mean

These results indicate that gonad weight and

eio'fcrl sir.2 of the fowl are not closely related ttfter 131 days of
o t-"6 v

To further study gonad size in relation to the seasons of the
year, additional observations were made oa male gonaus collected in
July and August 1942.

The results obtained are given in Table 9.

Table 9 Column 4 shows that the length of the left gonad in­
creases from 23.0 mm in Aug.-Sept. to a maximum of 40*5 nan in July
of the following year,

Gonads removed at the time these observa­

tions were made on the cloaca weighed 1546.7 mg in Aug.-Sept. and
increased to a maximum of 6797.3 mg in July of the following year.
The length and weight of the right gonad closely paralleled that
of the left.

These observations indicate that maximum weight of

the gonads is fairly closely correlated to maximum length of the
closca.
The results shown in this study would suggest that cloacal
size is influenced by endocrine factors associated with the gonads
and the anterior pituitary.

According to Marshall (1936) variations

in the gonsds are brought, about by two factors,

(lj endocrine

r,.ft bj

e

?

cl EE AND Vt'EIC-HJ' OF PFE GOV'TS OF THE ;;yT f y y
TTP^p.i ipj P/.YS OF AGE PHFO'IOH ir,r DPYS OF EGA:
fAdj I" C:r1'1 O F ' t

"r

cwl)

1C

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2

3

M1JTT-V’ >1

Yioutr: 4- Yef r
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Killed

1
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iU (T]>£ |
July
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(mm)

1941
1949
1942

1.941

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9 .9

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(ms)
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Hi phi
1546c7
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1697.7
2719.3
6660.3
23-17.0

O'

6c

factors associated w i i t h e gonads and the anterior pituitary and
(?' exteroceptive factors which through the intermediation of the
nervous .system act upon or modify the endocrine fee tors..
f io .p.

Riddle

thf’t eycn;m. amounts of pro Lac t in from the an terror

pituitary suppresses gonadal development in birds and oromotos grwoth
5r. some of the more important organs assoc la ten wi th the aiaes tive
system - especial ].y the intestines,

He further sngKefjts that ;.)>»

S;aisee of excess prolactin may cause the seas one; L evelie difference
in

the

gonads

of

lim s .

aoasri, Marshall, and Bissonnette (1937) agree that light is
probably the most stimulating of the exteroceptive rhetor*:,
Bisso-inette found thet by (l) increasing day length (2) increasing
intensity ana (3) greater intensities of longer waved rays near the
red end of the spectrum were the most activating phases of this
stimulus.,

evidence produced in this s n a y ana tnat. of the above

workers s u m r e s t h a t

the ccruolnti.on between maximum sice of the

fu,v.cr pr.u the youede on the 131 s_c nay and tno apparent leek of
^.hi e. c o m e Lr.tion after. the 13! .st day ..nu.y foe...duo to longto ox tos
1i !<
■bt dry ,

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63

in the male and female was attained from the 131 st day to the 156 th
day of aye,
Gbservi. tions made on the individual compartments have shown that
growth of the coorodaeuir. in the fowl increased rapidly up to the 7 th
day then remained fairly constant until the maximum was reached on the
l31 y_k day.

Growtn in length of the uroaseurn was essentially alike

in male and female until the 5? th day and then was greater in the
Terne.Le than in the male.

The increased length of the female cloaca

he tween the ares o f ly~> and 195 da.vs was shown to bo due nrimari lv
i.

‘ *^1

to the increase in length of the urodaeuni as the length of the copro-dcenm vpinainod fairly constant during that period..
It was evident from the data presented that growth in width of
the female urodaenm closely paralleled that of the male through the
131 st day but in the female increase in width was greater from the

131 st day until the 195 th day than it was in the male in the same
period.

It was also shown that in the transposition of the data

obtained for length and width of the proctodaeura at the various ages
•to., grow th, that growth -of.the proctodaeum was similar in the male
and female from hatching date to the 156 th day following which the
female showed a greater increase than the male through the 195 th
day.
Observations made on the cloaca! papillae showed that there
was no significant increase in growth of the uretal papillae from
hatching date through sexual maturity while growth of the genital
papillae in the male closely par^l .1eled that of the female through
the 32 nd day after which the male showed a greater increase than
the female until the maximum on the 131 st day.

Following the

131 st day the papillae in the female showed rapid atrophization.

*

It was made evident with the data given in this study that the
bursa, reached jr.axiir.um growth on the 59 th day in the male and on the
J-9I st. day in the female.
vestiye et sexual maturity.

It then decreased in both sexes to a
Results showed a correlation between burs

a trophize tion and sexual me. turi ty.

On tne basis of Riddle's observa­

tion it appears probable that gonadial development is retarded in post
natal ages by an excess of prolactin from the anterior pituitary until
maximum bursal «»rowth is attained.
Observations made on bursf 1 folds showed that there was no
significant increase in number of bursal folds in either the male, or
female fowl from hatching date to the 156 th day. after which there
was rapid a trophization of the folds through sexual maturity,.
Observations on the bursal canal demonstrated that the male
reached maximum width at an earlier age (7 days; than the female,
while in the female bursal canal width does not reach a. maximum until
the 101 s_t day.
It was further shown that bursal growth paralled fairly closely,
growth of the bursal canal while the number of bursal folds appeared
independent of bursal size and weight until the 15b th day, after
which decreased growth in the bursa closely paralleled decrease in
number of bursal folds.
Observations on the gonads made it perceivable that, growth, when
measured in. percentage increases of length, width, thickness and
weight, was fairly similar in the male and female fowl from hatch­
ing date until the 59 th day and that gonadial growth was greater
in the male than m
was reached.

the female from the p9 tn day until maximum size

It was further shown that gonad size in the male pro­

gressively increased to a maximum In August - September 1911? then

70

(

decreased in the following November, while gonads collected in the
preceding September again increased to a maximum size,

These results

indicated two factors important in aeterir.ining weight of the male
gonads, i.e., (l; age of the bird and (?;) seasonal variations.
To further study gonad size in relation to the seasons additional
observations were made on male gonads collected in July and August of
the following year (1947),

Results showed that maximum growth of the

male gonads was fairly closely correlated to maximum growth of the
c Lcf ca.
Investigations of Rowan, Bisaonnette, Marsha 11 and Riddle and
results presented in this study suggested that cloacal size is in­
fluenced by (1) endocrine factors associated with the gonads end the
anterior pituitary and (2) an exteroceptive factor (light) which
through the in termediation of the nervous system acts or modifies
the endocrine factors,

These factors likewise are probably re-

snonsitie for the correlation be tween maximum size of the cloaca and
gonads on the 131 st day ana apparent lack of correlation after the
171 st dav.

<

71

V. SUMMARY

1.

The cloaca of the fowl, partridge and pheasant consists of

three compartments; the coprodaeum which was the largest, the urodaeum which was the smallest arid the proctodaeura wnich was smaller than
the coprodaeum yet larger than the urod&eum.
2.

The cloaca1 compartments ana their limits were similar in

the three species studied.
likewise similar*

The position of the cloacal papillae was

All species showed the bursa connected to the proc-

todaeum by a funnel-shaped canai .

a

broad fold was observed in the

proctodaeum of the fowl, partridge and pheasant.
3.

A deep coprodael pocket ana & uret&l vestibule were observed

in the partridge while an oblique coprodael fold was seen in the fowl
and pheasant.

Uretai papillae in the pheasant were found on the

anterior edge of longitudinal folds and were not disc-shaped as in
both the fowl and partridge.

The bursal aperture was exposed in the

partridge 'while in the fowl and pheasant, it,.was. covered by the uroproctodael fold.
d.

Growth in size of the cloaca when measured in percentage in­

crease in length and width was greater in the female than in the male.
5.

Maximum size of the cloaca in the male and female fowl was

reached from the 131 st to 156 th day of age.
6.

Growth in the individual compartment of the cloaca showed

that the coprodaeurr. in the msle and. female fowl increased rapidly up
to the 7 th day and remained fairly constant until the maximum on
the 131 st day.

Growth in length of the urodaeum was essentially

alike in the male and female fowl until the 59 th day ana then was

greo ter in female then in male.
7.

The increased length of the feme.! e cloe or- be tween the apes

of 156 enc‘ 195 days wee hue to increased length of the urodneum.
o.

Growth in width of the feme.! e urcdaeum closely psa-alleled

tho t or the ieol e throe r'h the I.31 st cgy hut in the female tnor^ase
irs ninth was greater from the i.31 st day unti! the 195 th day than it
vr u in ibe male for the seme period,
9.

Growth of the .'.rootpd-ceum wee similar ir, trie male set femr ]e

frnTv hr- *■chirp dr f° until, ftp [5I th day,
u'nov'ofi a greater increase thur* the male
10,

Fol bn-ing;w m oh the female
through the L95 th day.

There was no significart growth in the uret-l! prri 1l»e from

hatchi nr date through Per ua], maturity while growth in the genital
{..r4 d.ll ho of the male close'y paralleled that of the female through
the 30 nd day, after Th 1oh. the m.aJ.e snowed r,. greater .1ncre&se t-han
the eerr.el e ►

The genital papillae in the female showed rapid atro--

phi ration a f ten- the 131 s_t day.

1.1., The bursa reached maximum growth or the 59 til any in the
male and 131 ,s_t day in the female,

12,

fiesuite showed a correla cion be tween bursal 0 irophi nation

and sexual, me tur^ t.y which on the basis of Riddle1s observe Lions may

he due to pro’
13,

hi n .

There wa r re sl.gnifjcent increase in the number of bursal

folds from hatching date to sexual maturity.
If.

Results of this study and those of Rowan, Bissonnette,

Marshal 1 and Piddle suggest cloaca1 s.ire is influenced by (l)
endocrine factor's associated with the gone dr. and the anterior
r-ibuitery find (£) an exteroceptive factor (light) which through the

73

in termed ir. t,ion or* the nervous system acts upon end modifies the
end ocr ir.e fee t o r ,

74

f

VI. LITERAfURF CITFX-

Adelfrtmn, H. B. 194" • fiie embryology re1 treatip.es of Hieronymus
Frbricius of / gur.pendente - Cornell University Press, Ithaca,

q
on. ?/,1-/70*

1?37,

’’notope-''!odicity*

Wilson Bull., vol. 49.

Ca'i'onu, ft. T , 'cj-l* ilip microscopic {,;■lomy of trie cierhive
h'fict of Go 'lus lomeoticus - Tc;."1 G'e b- Colie "e J . 3ei,, ve! ,
'■
> ’4■-• •'-9 - .• •
Fr.rh-es. V » g,,
Son,

1877.

London.

op,

The bursa F?br 1fij
.I i r

biro s ,

Proc - fool -

394--312«

f-f-dow, H, 1337. Remarks on t.bo
m :c copule lory organs
of the amniotH , Pinion, fro Tie., vol . 173, Sari ■re P, np. 5--37,
Goner-, V:. C. 1939* fro.rsac Lion of tire Fourth North Amer.i can M i d
life Conference. American Wild Life Institute, Washington,
Lb. C.
Groebhels, Fra mi 1931- i)sT' Vogel..
Garbruoer Born tra egor} Berj in.

1st, sd., op. \u6-46 7 ->

Jolly, J. 1913* 1.1involution ybysiolorique be In bourse de
Febricius et res relations svec 1 'apperition de Is moturite
sexuelle. Compt. Reno. Son.. Biol. Pr-r‘ir, vol. 75? pp. 633699
,

Jolly, J, 1915. La bourse de Fabriciur. et les orgunea lynrphoegi the! iaux, arch., Anal:,., vol. ’6, pp, 363-34".
Kaufman, I. 1997.
Rscherches sur l« cro.iss&nce ciu corps et des
or genes uu pigeon,
Biol,, genet*. 1,, vol.. 3. pp. 105-128,
Keupr, P. F, 1913.
The Anatomy of the domes tic fowl, pp. 151119,
V». B„ Saunders Company, Chicago..
Kirkp*. trick, 0. M. 1944.
The bursa of Fabrieius in Ringnecked
pheasants. J. '.Vila life ?agt,, vcl. 8 , pp. 118-129.

Is timer, H - B. L?,74. P o s t n a t a l growth of t h e body, systems, and
organs of S i n g l e Comb v"hi i e Leghorn c h i c k e n s .
J, Agric. Res. ,
vol. ??, pp. 363-397*
Lindurbe, J. P. 1943• A gross study of t h e bursa of Fabricius
and cock spurs as age indicators in Ring necked phot cents,
n r , 1/6 ! ??.
.uv, V O 1 . 60

75

Marshal1, F. H. A.
determine it.

1936. bexuaj pericdjcity and the causes which
Nature., vol. 137, pp. 1056-1057,

Meleod, h. ¥•,. 1939. Anatomy of the digestive tract of the domestic
fowl. Vet. W e d v o l . 34, up. 713-717.
Mitchell, H. P., I . E. Card, arid f. 5. Hamilton 1926., The grow th
of Vfhite Plymouth Rock chickens. III. A p t . Exp.. Eta- Eull, 273.
Parker, J . S., F. ir. McKenzie, and H„ I. Kemps ter 1942. Develop­
ment of the testes and combs of Vihi l.e leghorn and New Hampshire
cockerels.
Poult. Sci,, vol.. 31, pp. 35-44.
Re *■t e r e r , E.
15*35 • C o n t r i b u t i o n a ’ 1 f e tude ci'i o ’ on a up e t de Je
hours'- up P a b r l c i u s ebes les oi ser. uy,
J . A r a l . Par j .; ; . , vol .
\

....

?

? i"i■ -•“ "***' *

0 , l1-/,'? •
rij. wjl /j,-.
Physiol., vol. 36, pp. 343-26$.
Riddle, 0. 1936. Prolactin, a product of the anterior pituitary,
and the per
part it. plays in vita] processes. Sci. 00 ,, vol. 47,

no. 97-j13,
Rowan, Cm, 1931- fho riddle of migration.
end Wilkins Company, Baltimore,

pp. 119--123•

hilliams

Sisson, S. I.933 * 1'he anatomy of the domestic animals. Revised, by
J. C, GrossTrar. p. 940. V?. B. Saunders Company, Philadelphia.
Ward, R. Yd, and B, A. Gallagher 1920, Diseases of domesticated
birds, p. 13. Maori, 1]an Company, New York.

7A

VII, ACKNOVsIli.iiGMEw f7

The author v;i shop to thank Lr • E. A. Fennel I for his vrrection
sn'.' l.elpfn i. suie ',est •ons in the wi'ifinc ot‘ this roeuuscrj ot.
An express') on of appreciation is tIso due Dr. H. H. Bunt, Heed
of the Depsi-tmen t of Zoology, for making possible such ir-s\eriel end
specimens os were necessary j

this work,, espec is.]J.y the five months

eerie:-, re well or to ifr. lion "ecfteirie, onu Miss Icrr.ei.ne Wilson,
who Resisted in making the sketches, and Mr. Horry Prediuore, who did
the r»hotorTophic work.

To Dr. ¥:ii pf Pi.rnip. ni.re'’tor of the h. X .

Tellopc hii'o Sanctuary, for his help in the selection of the problem,
end Dr. Carl Gower of the Ste te Conserve tion Department for rid. in
obtaining ma terie 1 from the Stele Game Farm, the author wishes to
express his sincere appreciation.

<

VIII. VITA

Clf re He.!me’- Bennett., born, Springport, Michigan, May 29, 1903; son

of Georye Van Black Jr.., mid Belle (Belmer) Van

Elack;

educated,

Sorirgport, Mohican: ah aye of nine years took surname Bennett from
stepfc.ther; B. A., Vies tern Michigan College of Education, 1929; K.
•Jniver? >.ty of Michigan, 1933; monied Marian Hitt., Spring Arbor,
Michigan,

August id, 1934; two sons, Spencer Clare

and Eric Helmer;

taught in rural schools, -Tack;-on County, Michigan, 1923-26; taurht
in Battle Creek Public Schools, &rtt.le Creek, Michigan, I'>29-30;
taught in AlbionPublic Schools, Albion, Michigan,

1930-37; graduate

work, University of Washington, summer, 1935; University of New
Hampshire, summer, 193o; university of Michigan, 1937-38; instructor,
Grand Rapids Junior College, Grand Rapids, Michigan, first semester,
1938-39; instructor, tiestern Illinois State Teacher's College, second
semester, 1933-39; instructor, Miami. University, 1939-40; graduate
assistant, department of zoology, Michigan State College,- 1940-42;
Assistant Professor of Biolog;/, Northern Michigan College of Educa­
tion, 1944-44: Assistant Professor of Zoology, North Dakota
Agricultural College, second semester, 1943-44; Assistant Professor
of Biology, Bowling Green State University, 1944-•