596 DR MARSHALL AND MR W. A. JOLLY 



5. Graft left for three months. Normal corpora lutea and cysts were found present. 

 Killed during breeding season. 



6. Graft left for eight months. A few corpora lutea and follicles were present, with 

 relatively large amount of stroma. This rat was killed in October, i.e. during the non- 

 breeding season. 



7. Graft left for five months. The ovarian stroma was unaltered. Some luteal 

 tissue, follicles, and cysts were also present. 



8. Graft left for six months. Shows follicles and corpora lutea. 



In seven other cases of homoplastic implantation partial success was obtained. The 

 tissue is recognisably ovarian, but has become considerably altered. 



Five experiments must be described as unsuccessful, the grafted tissue either being 

 entirely absorbed or replaced by connective tissue. Cysts were found present in each 

 of these cases. 



II. Heteroplastic Implantation. 



Six operations were performed in which ovaries were removed from one rat and 

 implanted on the peritoneum of another. 

 Two cases were attended with success. 



1. The ovaries were removed from a rat and transplanted to the peritoneum of 

 another whose own ovaries had previously been removed. The graft (fig. 3) was left 

 for three and a quarter months, when the animal was killed. Examined microscopically, 

 the graft showed ovarian stroma and corpora lutea. The two rats were possibly of the 

 same litter, but this was not certainly known. 



2. The ovaries were removed from a rat and transplanted to the peritoneum of 

 another whose own ovaries were not removed. The two rats were of the same litter. 

 The graft (fig. 4) was left for one and a half months ; it contained follicles and ova. 

 The stroma had become degenerate in places. 



Four other similar experiments, while not entirely satisfactory, met with some 

 success. In one of these the ovaries were transplanted to a male rat. The graft 

 showed recognisable ovarian tissue in parts, but had undergone very considerable 

 degeneration. 



A number of experiments were also performed in which ovaries from one rat were 

 grafted under the skin on the anterior abdominal wall of another rat. In three such 

 cases some success was obtained, but a larger number of grafts was absorbed than when 

 the implantation was intraperitoneal. 



It will be observed from the foregoing account of our experiments that it is possible 

 to excise and graft ovaries in such a way that in many cases the grafts exhibit the 

 characteristic histological features of ovarian tissue. The germinal epithelium had, 

 however, always become absorbed in our experiments. In other cases a certain amount 

 of degenerative change took place, only certain elements of the tissue being recognisable 

 after the lapse of several months ; thus the stroma might present its normal appearance 



