396 PHILOSOPHY OF ZOOLOGY. 



When the ovum bursts from the corpus luteum, or 

 gland in which it has been prepared, it enters the Oviduct, 

 or Fallopian Tube, through which it is conveyed to the 

 uterus. The extremity of the oviduct, next the ovarium, 

 is somewhat funnel-shaped, and its margin is irregularly 

 divided into leaves, or fimbriae. This structure is con- 

 sidered as useful in aiding the expulsion of the germ from 

 the corpus luteum, and in receiving it more readily into the 

 tube. The oviduct itself has walls of a cellular substance, 

 with abundance of bloodvessels, and traces of muscular 

 threads. It is more or less tortuous in its course, and 

 terminates by an opening in the upper part of the cavity 

 of the uterus. Both oviducts open, in some cases, very 

 near each other, while, in other instances, they are more 

 remote. 



The Uterus, or matrix, exhibits a great variety of shape 

 in different quadrupeds. In general, however, it is length- 

 ened in the direction of the body, receiving, at its summit, 

 the oviducts, and terminating below in the vagina. Its 

 walls are remarkably dense, and they are liberally supplied 

 with bloodvessels, absorbents, and nerves. The propor- 

 tion between the size of the cavity and the thickness of 

 the walls, is likewise very various. The cavity itself ex- 

 hibits several remarkable peculiarities. 



In the most simple form of the uterus, the cavity is 

 somewhat pear-shaped, and the oviducts enter it at its lar- 

 gest end, by very small openings. This shape prevails in 

 the human race, the apes and sloths. It is called Uterus 

 simplex. The next shape, in point of simplicity, is where 

 the cavity divides at its summit into two processes, or 

 horns, as they have been called. These are either straight, 

 or variously convoluted,' and terminate in the oviducts. 

 This kind is termed Uterus bicornis, and may be seen in 

 the dog, hedgehog, and the ruminating quadrupeds. ' In 



