150 CARL R. MOORE 



The end result of follicular atresia is the conversion of the 

 follicular masses (stratum granulosum) into the large-sized cell 

 masses, blackening with osmic acid, which are commonly spoken 

 of as the interstitial cells of the ovary. 



B. The testis 



Transplantation of testis has been far less successful than the 

 ovarian transplantations, as was found true in the writer's earlier 

 experiments. However, practically all experimental work has 

 indicated that the testicle is a more labile organ than the ovary 

 and more subject to modification than the latter. So far as the 

 writer is aware, all cases of testicular transplantation in mammals 

 have resulted in an interference with spermatogenesis; the 

 spermatocytes and spermatozoa disappear and usually only a 

 few scattered cells remain in the tubules, such cells being con- 

 sidered as the cells of Sertoli. Many investigators, however, 

 have found that mere ligation of the vas deferens results in a 

 similar disappearance of the germinal epithelium, so that it is 

 only to be expected that the tubules of persistent grafts would 

 be devoid of their normal germinal epithelium. 



At the time of the transplantation a small part of the testis 

 was introduced into a subcutaneous pocket in the female, and as 

 the substance of the organ readily escapes from its connective- 

 tissue capsule the loose tubular mass was separated by the 

 ingrowth of connective tissue into the implanted material 

 during the process of wound healing. When the graft was 

 sectioned the tubular mass was found closely encapsulated and 

 infiltrated with connective tissue, as can be seen from figure 13 

 (section of a 152-day testicle graft from female 40 4 A2B2 III). 

 The tubules are perfectly distinct, well rounded in section, even 

 though containing no cellular material other than the Sertoli 

 cells, while connective tissue surrounds the entire mass and is 

 present between the tubules. Figure 14 (a section of a 232-day 

 graft from female 49 B) is a more highly magnified drawing of 

 a few tubules. 



The principal tissue of the testicle, aside from the seminiferous 

 tubules, is the interstitial cell masses normally located between 



