24 Veterinary Obstetrics 



The superficial layer of the mucosa of the oviducts consists of 

 ciliated columnar epithelium, with the cilia vibrating toward the 

 uterus. The oviduct is the most rigid and undilatable portion of 

 the genital tube and has for its ofSce the conveyance of the ovuni^ 

 fecundated or otherwise, from the ovary to the uterus, in which 

 function the cilia apparently play an essential part. The duct 

 also provides passage for the migration of the spermatozoa of the 

 male, which, advancing from the uterus toward the ovary, meet 

 the ovum within this narrow passage and fecundate it. In rare 

 cases the fecundated ovum lodges in this duct and undergoes par- 

 tial development, to constitute tubal pregnancy (which see), but 

 its undilatability serves as a rule to cause a rupture of its walls 

 and leads to the escape of the fetus from the duct into the ab- 

 dominal cavity to either cause sudden death of the animal from 

 hemorrhage or constitute extra-uterine or abdominal pregnancy 

 (which see). 



4. The Uterus. 



The uterus is a musculo-membranous sac designed for the re- 

 ception, attachment, nutrition and protection of the ovum and 

 finally aids in the expulsion of the fetus at the time of birth. 



Derived from the ducts of Mueller, it varies greatly in form and 

 disposition, partly dependent upon the degree of fusion between 

 those two structures. There are generally recognized a uterine 

 body and two cornua, each having essentially like functions in 

 varying degrees. 



In the rabbit, there exists no uterine body, but two distinct tub- 

 ular uteri opening separate^ into the vagina. In the bitch, cat 

 and sow the uterine body is limited in extent and physiologically 

 unimportant, rarely containing even a portion of a fetus except 

 in transit at the time of birth, while the two cornua are exten- 

 sive and in them develop virtually all the fetuses so that, physio- 

 logically, they represent the two separate uteri of the rabbit. 



In ruminants, the uterine body becomes markedly greater in 

 size and assumes far higher importance physiologically, while the 

 cornua remain relatively large. 



In these animals the one, two, or more fetuses habitually rest 

 almost equally in the body and cornua so that they represent a 

 middle point in the transition between the double uterus of the 

 rabbit and the single uterus of woman, physiologically devoid of 



