22 THE SEX-COMPLEX 



Ovarian to how and where it is or they are produced. The only 

 . evidence that there is an internal secretion rests upon the 

 ' t results of extirpation, destruction and implantation ex- 

 periments, and to a lesser degree on histological and 

 clinical observations. The atrophy of the uterus which 

 follows oophorectomy is believed to indicate the loss of 

 some secretion which normally activates this organ. Some 

 think that there is more than one secretion ; and various 

 investigators have considered that, while different 

 hormones are produced by the lutein cells of the corpus 

 luteum, by the interstitial cells of the stroma of the ovary 

 and by the membrana granulosa cells, these secretions 

 all differ in regard to the degree of importance and the 

 period of action to be assigned to each, and that the 

 total effect differs in different animals. And herein lies 

 one of the great difficulties in the study of our subject : 

 different orders of mammals have organs of internal 

 secretion which are structurally and functionally dif- 

 ferent, although perhaps in degree only. Individuals 

 in the same species may vary, both in animals and in 

 Man ; consequently some of the contradictory state- 

 ments made by different experimenters may be explained 

 on the ground of these variations. It may be, for 

 instance, that the secretion of the corpus luteum in 

 women is much less important for the normal implanta- 

 tion of the ovum than it is in rabbits 1 . 



It will make the subject clearer if I consider shortly 

 the supposed activities of the different secretory elements 

 in the ovary, and reserve the discussion of the total 

 effects produced by the removal of the secretions until 

 later. 



SECRETORY STRUCTURES OF THE OVARY 



The foiiicuiar The follicular epithelium. The cells which enclose 



epithelium, the ovunij an( j are known as the follicular epithelium, or 



membrana granulosa, are supposed by some to produce 



1 See Effects of Oophorectomy, p. 29. 



