116 PEOr. M. WATSON ON THE ANATOMT OF THE 



Exterior of Uterus. — The uterus consists of a central body or corpus and of two comua. 

 Each cornu, from the point of entrance of the Fallopian tube to the junction with its 

 fellow of the opposite side, measures 6 inches in length, and describes a well-marked 

 curve, the convexity of which is directed forward. Each of the uterine horns is flattened 

 from above downward, and measures f inch in breadth at its junction with its fellow. 

 They diverge at once from one another, so as to leave close to their junction an interval 

 of a triangular form, which is filled up by peritoneum. The corpus uteri, lying between 

 the layers of the broad ligament, measures 7 inches in length from the junction of the 

 comua to its opening into the vagina. It is somewhat flattened from above downward, 

 and has a uniform diameter of 1 inch. The corpus uteri lies altogether in front of 

 the bladder, and is completely invested by peritoneum. It differs in this respect from 

 the vagina, which, lying between the bladder and rectum posterior to the line of re- 

 flection of the peritoneum from the uterus to the neighbouring viscera, is altogether 

 devoid of serous investment. The body of the uterus is tliick and muscular. There is 

 no trace in my specimen of the external constriction whicli, according to Miall and 

 Greenwood, indicates the separation of the uterus from the vagina, this separation being 

 visible on the interior of the organ only. 



Interior of Uterus (fig. 1, PL XXIL). — Upon slitting open the cornua uteri, these are 

 seen to be lined by a uniformly smooth mucous membrane, which presents no trace of 

 the longitudinal rugse so commonly met with in other mammals. From the point of 

 junction of the uterine horns a well-defined septum uteri extends backward through the 

 ■whole length of the corpus uteri, as well as through that of the vagina to the opening of the 

 latter into the urino-genital canal. This septum, therefore, separates the bodyof the uterus 

 into two perfectly distinct compartments. It is thick and opaque so far as it lies within 

 the cavity of the uterus, but becomes thin and translucent within the vagina. This difl!"er- 

 ence in appearance of the septum at diff'ereiit parts is due to the fact that, within the 

 uterus, the mucous membrane covering the septum as well as the uterine walls is 

 thrown into longitudinal ruga;, which, few and ill-defined at the junction of the cornua, 

 become more numerous and of larger size further back, but cease entirely at the os 

 uteri. Within the vagina neither the septum nor the vaginal walls present the slightest 

 trace of mucous folds, the membrane being here perfectly smooth and closely adherent 

 to the muscular parietes of the canal. In consequence of the complete development 

 of the septum uteri throughout the whole length of the body of the uterus, this organ 

 communicates with the vagina by means of two distinct apertures or ora uteri — an 

 arrangement which is almost identical with that which occurs in the Leporids. In 

 the Hares, however, the vagina is simple and presents no trace of the mesial septum 

 which in the Indian Elephant (at least in my specimen) separates that tube into two 

 distinct compartments. The separation of the uterus from the vagina, although not 

 defined externally except by the line of reflection of the peritoneum to the neigh- 

 boui-ing viscera, is indicated in the interior of the organ by two well-defined folds of 



