Atretic Follicles 395 



1. Atretic Follicles 



There are commonly observed in the ovaries of heifer 

 calves, heifers, and cows numerous small cysts, varying 

 from 1/16 to V4 inch in diameter, containing a clear liquid. 

 They appear to be the remnants of follicles in which the 

 primitive or permanent ova have perished and the follicular 

 liquid has persisted, with more or less addition to its volume. 

 I have stated that they grow as large as V4 inch in diameter. 

 How much larger they may grow is at present difficult to 

 state. They may grow much larger but, should they do so, 

 become confused with cysts of other origin and lose their 

 identity. That is, when a larger cyst is encountered and 

 neither clinical nor histological evidences of origin are 

 forthcoming, accurate differentiation is impracticable. 



The significance of these small cysts is unknown. If 

 they elaborate important secretions (endocrines) or in any 

 other manner modify the sexual functions, or if they affect 

 in any way the reproductive functions, the fact has not 

 been demonstrated. They are quite as numerous in ovaries 

 which function normally as in those which do not. 



2. Cystic Degeneration of the Ovisacs. Nymphomania 



There occurs in all species of domestic animals, though 

 preeminently in the cow, a type of cystic degeneration of 

 the ovaries accompanied by nymphomania. So far as can 

 be determined at present, the degeneration is one involving 

 the unruptured ovisacs. Apparently this undergoes dis- 

 tension, the follicular liquid becomes enormously increased, 

 the ovum perishes, and there is little tendency for the cystic 

 follicle to rupture and recover spontaneously. 



It would appear quite certain that the cystic disease is 

 one of the ovisac itself, because, so far as I have been able 

 to determine, there is never any lutein tissue in the cyst 

 wall. In nearly all adult ovaries there are vestiges of cor- 

 pora lutea, but in nymphomania they are purely vestigial 

 and are not connected with, or visibly related to the cysts. 



I have not known nymphomania to develop in a pregnant 

 animal. There are large and small cysts in the ovaries of 



