INTERNAL ORGANS OF GENERA TION. 45 



Cow, they are short; but in those which are multiparous (more than one 

 foetus), they are long in proportion to the number of young they bear, 

 while the body is diminished in length. In the uniparous animal the foetus 

 is developed in the body of the uterus, and its posterior extremities only 

 are sometimes engaged in one of the cornua ; but in the multiparous 

 females the cornua resemble the intestines, and the young are developed 

 in them, the body of the uterus seldom containing any. In the Rabbit, 

 indeed, there is no corpus uteri, the cornua opening independently and 

 directly into the vagina. 



As gestation proceeds, the uterus of course increases in volume, and 

 pushing the pelvic curvature of the colon forward out of the pelvic cavity, 

 it gradually descends towards the floor of the abdomen, on which it at 

 length rests, towards the middle line, until the end of this process. Dur- 

 ing this change of position, it draws with it the cervix and the vagina, 

 which becomes notably elongated, and even the vulva is carried forwards 

 until it appears to be buried between the ischiatic tuberosities. 



After parturition the uterus gradually diminishes in size, and some of 

 its supplementary structures disappear ; but it never resumes its previous 

 volume. 



The Hgaftients of the uterus suspend it loosely, yet securely, in the ab- 

 dominal cavity ; and while allowing it a certain range of movement, per- 

 mit its full development during gestation. At this period they become 

 developed in a peculiar manner, and, as we have seen, between their la- 

 minae appears a layer of muscular fibres ; in the Cow these fibres are 

 arranged in fasciculi, one of which, larger than the others, extends from 

 the ovary to the cervix uteri. These ligaments would also appear to 

 stretch considerably in version or inversion of the uterus in the her- 

 bivorous animals ; even in the carnivora they accompany the uterus when 

 hernia takes place ; and in the torsions of this organ which sometimes 

 occur in the herbivora, when its upper face becomes the lower, or even 

 when it has made a complete turn upon itself, they entangle and strangle 

 the uterus at the cervix. 



SECTION III. — FALLOPIAN TUBES OR OVIDUCTS. 



The Fallopian tubes or oviducts are two small, cylindrical, flexuous 

 canals, about ten inches long, white in appearance, one of which is lodged 

 in each broad ligament between its serous layers, and near its anterior 

 border. Each tube commences at the extremity of the uterine horn, at a 

 small hard tubercle in its cul-de-sac {pstii^m uterinum). This tubercle is 

 its opening into the horn, and from this it proceeds, more or less tortu- 

 ously, and increasing slightly in diameter, towards one of the ovaries, 

 upon which it terminates by a free, widened extremity (ostium abdominale) 

 in the pavilion of the tube. The calibre of this canal is small, and 

 scarcely admits a thin straw at its middle portion, and it is still smaller 

 towards the uterine extremity ; as it approaches the ovary, however, it 

 increases in width until it ends in the pavilion. The uterine extremity 

 of the canal opens through the small hard tubercle just referred to as 

 existing at the cul-de-sac of the cornua. The ovarian extremity offers in 

 all the mammalia a peculiar disposition. It opens into the peritoneal 

 cavity of the abdomen (the only instance of a serous cavity communi- 

 cating with the exterior), near the ovarian fissure, in the middle of the 

 pavilion, which is also named \.\i% fimbrica tubarum, or morsus diaboliy 



