324 THE PHYSIOLOGY OF REPRODUCTION 



The successfully transplanted ovaries exhibited all the 

 characteristic histological features of normal ovarian tissue, 

 excepting that the germinal epithehum was invariably absorbed 

 after the lapse of a short interval. In some cases a certain 

 amount of degenerative change took place, only certain ele- 

 ments of the tissue being recog- 

 nisable after the lapse of several 

 months ; thus, the stroma might 

 present its normal appearance 

 while the follicles had disap- 

 peared, or the greater part of 

 the graft might be composed of 

 luteal tissue alone. It was also 

 observed that the successfully 

 transplanted ovaries underwent 

 the same cycUcal changes as 

 normal ovaries. Thus, in animals 

 killed shortly before the com- 

 mencement of the breeding 

 season, large folhcles were found 

 in the grafts, while at a later 

 period corpora lutea were present, 

 showing that ovulation had 

 occurred in the transplanted 

 ovaries. In one case, a homo- 

 plastic graft was found to be 

 normal after fourteen months, 

 while a normal heteroplastic 

 graft was composed entirely 

 of healthy ovarian tissue (with 

 folhcles and ova) after six 

 months. In these experiments 

 the ovaries were grafted into the substance of the kidneys. 



Homoplastic transplantation was found to be more easily 

 accomplished than heteroplastic transplantation. This result 

 could hardly be ascribed to increased difficulties in the per- 

 formance of the latter operation, since the technique was 

 identical in each case. Furthermore, our successes in hetero- 

 plastic transplantation were usually obtained in experiments 



B'iCi. 72. — Transverse section 

 through uterus of rat after 

 ovariotomy, showing degener- 

 ative changes. (Gf. Figs. 71 

 and 73. From Marshall and 

 Jolly.) 



