6o 



Diseases of the Genital Organs 



direct : that is, when the ovum is discharged from the ovi- 

 sac, its direct connection with the tissues of the mother is 

 finally and permanently severed. The fertilized ovum at 

 first lies free upon the uterine mucosa while nutrient fluids 

 poured out by the endometrium are absorbed by the ovum 

 to provide for its development. Thus far, the life of the 



Fig. 28 — Fetal Cotyledon of Cow showing primary and adventitious 

 Placentae. Photograph. 



ovum has been supremely precarious, relying wholly upon 

 a delicately balanced physiologic state of the oviduct and 

 uterus and their contents. It has no known inherited power 

 to resist the attacks of any bacteria contained within the 

 tubo-uterine cavity and has no known power to maintain a 

 given location. Clinical observation leads readily to the be- 

 lief that the mortality of the fertilized ova during this period 



