192 PROF. DAVID HEPBURN 
by the vas deferens, which now assumed the mesial position to both of the others. Up to 
this point the ureter had not entered the pelvic cavity, and about three-quarters of an 
inch onwards, that is, in the direction of the tail, the ureter, still lying close to the pelvic 
brim, entered the lateral aspect of the urinary bladder, travelling between the folds of 
a lateral vesical mesentery or peritoneal ligament. ‘Thus, as a consequence of the great 
obliquity of the pelvic inlet, the ureter was able to reach the bladder by skirting the 
pelvic brim, and at no point did it require to enter or sink into the interior of the pelvis. 
The urinary bladder was placed mesially, and was attached to the ventral wall of 
the abdomen by a ventral mesial mesentery composed of peritoneum, which, as formerly 
described, closely invested the bladder except on its pubic aspect. The apex of the 
bladder extended to the umbilicus, where it still presented an open lumen. ‘There was 
no obliterated part or urachus, and throughout its entire length it presented a uniform 
calibre, suggestive of an empty portion of small intestine. Developmentally, it may be 
said to represent an enlarged and patent allantois; but as this animal was only two days 
old at the time of its death, probably a sufficient period had not elapsed for the closure 
of the umbilical end of the organ. 
The hypogastric arteries were carried along each lateral aspect of the bladder, 
suspended in peritoneal folds half an inch in width, so that these arteries were not in 
contact with the wall of the bladder until they reached a point between 2 and 3 inches 
from the umbilicus, where the peritoneal folds disappeared, and the arteries closed in 
upon the sides of the bladder. 
The length of the bladder from the umbilicus to the prostate gland was 10 inches. 
The prostate gland lay close to and on the abdominal side of the symphysis pubis. 
The interior of the bladder was lined by a mucous membrane, presenting numerous 
rugosities, which to a large extent lay parallel to each other, and in the longitudinal 
axis of the bladder. Towards the outlet the mucous membrane became comparatively 
flat and smooth. 
The orifices of the ureters were longitudinal oblique narrow slits 2 mm. in length and 
5 mm. apart. The lateral margins of each of these openings were continued towards 
the outlet as slight ridges for a distance of 10 mm. These ridges met in the mesial. 
plane, thus forming a mesial longitudinal ridge or uvula vesicee. The actual trigonum 
vesicee was therefore a triangular area 5 mm. wide at its base and 10 mm. long on 
each side. 
The uvula vesicze was continued into the urethra, and became continuous with the 
erista urethree, which attained its greatest prominence 20 mm. from the apex of the 
trigonum vesice. The sinus pocularis was represented by a very small mesial aperture 
opening on the distal side of the summit of the crista urethree. 
The prostate gland did not attract attention, and at first sight one wonld have 
doubted its presence. Certainly in cutting into the urethra from its pubic aspect no — 
variation in consistence was detected. Still, there was a definite thickening of the pubie 
wall of the urethra corresponding to the general position of the urethral crest. On the 
of Myre Pegi era luce e 
