240 



INTERNAL SECRETIONS 



female sex hormones. In view of these considerations, it 

 seems justifiable to assume that the folhcles undergoing 

 atresia, and the cells derived from the latter, represent in 

 the ovary a gland with an internal secretion. One might 

 object that this may be true only for the species on which 





Fig. 109. — Disappearance oj primary ova in highly hyper- 

 trophied minute ovarian fragments. x 200. 

 A. Normal ovary of rabbit 18 months old (Prot. Nr. 50). 



the above-mentioned experiments were made, and for those 

 species where there is an interstitial tissue in the ovary like 

 that in the rabbit: But we have seen that no essential differ- 

 ence exists between the follicle undergoing atresia and the 

 interstitial tissue like that of the ovary of the rabbit. 



