OVARIES IN TELEOSTEAN AND ELASj\rOBRANOH FISHES. 199 



ostensibly been softened and absorbed bj the action of tlie 

 cells of the follicular epithelium. I could not find any very 

 definite remains of the germinal vesicle in this egg". It 

 ■would be interesting to know whether the degeneration of 

 the cytoplasm succeeds that of the nucleus, or vice versa. 

 Unfortunately I cannot answer this question at present. 



At the stage shown in fig. 21 the absorption of the egg by 

 the follicular epithelium is completed. The ovigerous pouch 

 in this case is about the same size as the last. The cavity 

 originally occupied by the egg is entirely filled up with a sort 

 of nou-vascular adipose tissue, which is the product of the 

 activity of the follicular epithelium. Tlije latter has, in fact, 

 become infiltrated with fat resulting from the decomposition 

 of the egg. It is important to state that the membrana 

 propria f olliculi is still intact between the follicular epi- 

 thelium and the theca folliculi, a circumstance which pre- 

 cludes the possibility of the fatty tissue being derived from 

 the connective tissue. The existence of this membrane must 

 also have prevented the entrance of leucocytes into the egg. 



The theca here (fig. 21) is much thicker than it was in the 

 earlier stage of the abortive follicle (fig. 20). It was found, 

 on examining a number of such follicles, that a thickening of 

 the theca follows the degeneration of the egg and accom- 

 panies the proliferation of the follicular epithelium. The 

 cause of this thickening of the theca and proliferation of 

 the granulosa is readily understood if we assume that these 

 tissues do not cease to grow on the death of the egg, but 

 continue active. In normal follicles the increase in volume 

 of the egg keeps pace with the growth of the theca and of 

 the follicular epithelium, with the result that these layers are 

 more attenuated than in follicles in which the egg has 

 stopped growing for some time. There is no special vascular 

 development in the Avails of these abortive follicles. The 

 ovary in this particular case is in an immature condition, and 

 both muscles and blood-vessels are but slightly developed. 



Abortive follicles, similar in structure to those just 

 described, and filled either partially or completely with the 



