272 INTERNAL SECRETIONS 



generative cells being necessary (' 'follicular theory "). Another 

 possibility must also be taken into consideration. It is con- 

 ceivable that the processes which take place in the cells of the 

 granulosa or the theca interna are primary processes, both 

 causing the development of the ovum, and at the same time 

 being connected with hormone-production in the cells of the 

 follicular wall itself. 



B. OTHER VERTEBRATES. 



It would be of great interest to know whether endocrine cells 

 of a nature similar to those in the mammal occur also in the 

 ovaries of other vertebrates. But we have already mentioned 

 (Part A, Sect. 6, a) how conflicting the statements of different 

 authors are concerning follicular development and the existence 

 of the corpus luteum among lower vertebrates. 



It was claimed that in amphibians the hormonic action which 

 the ovary has on the soma, must be due to the ova, since there 

 are no epithelioid interstitial cells present. We related in 

 Chapter IV. the experiments of Harms (1914, p. 117) on 

 Bufo vulgaris. He removed the testicle while leaving un- 

 touched the Bidder's organ. Harms relates that he observed 

 in the operated animals the cyclical hypertrophy of the pads; 

 the animals showed also the clasp reflex. If both the testicles 

 and the Bidder's organ were removed, signs of castration 

 showed themselves. But the cyclical changes took place in 

 those animals into which after removal of the testicle and of 

 the Bidder's organ, the latter was engrafted into the dorsal 

 lymphatic sac. Harms considers the Bidder's organ as a 

 rudimentary ovary in which interstitial cells are not to be 

 found. So he concludes from his experiments that the germi- 

 native cells of this organ are capable of producing sexual 

 hormones. 



The experiments of Harms were repeated, and by no means 

 confirmed, by Guyenot and Ponse (1922, 1923). These authors 

 stated that removal of the Bidder's organ alone does not inter- 

 fere with the normal cyclic changes of the pads or with the 

 sexual behaviour. And contrary to the results obtained by 

 Harms those animals whose testicles were removed (the Bidder's 

 organ remaining untouched), showed no development of the 

 pads when operated upon in June ; those animals which were 

 operated upon in October at a time when the pads of the 



