388 Mr. E. S. Carmichael and Dr. F. H. A. Marshall. [Apr. 10, 



with these questions, and to state the conclusions which we have reached 

 regarding them. 



Influence of the Ovary upon the Uterus. 



A brief resume' of the experimental evidence adduced upon the existence 

 and nature of the ovarian influence has been recently given in a paper 

 by Marshall and Jolly (1907), who cite observations showing that the uterus 

 undergoes undoubted degenerative changes after the removal of the ovaries. 

 Further evidence, which is in accord with this conclusion, has been inde- 

 pendently reached by Carmichael (1907). For accounts of the literature 

 reference may be made to these papers. 



Since, however, certain of the conclusions arrived at are still matters 

 of controversy,* it has been thought worth while to. place on record the 

 results of further experiments upon rabbits, dealing, firstly, with the effects 

 of ovariotomy in full-grown adults at different periods after the operation, 

 and secondly, with the effects of the same operation in young animals. 



It has been suggested that the cbanges occurring in the uterus may be due 

 to an interference with the blood supply to that organ, in the removal of the 

 ovary. The uterus in the rabbit, as in the human subject, has an independent 

 vessel of supply derived from one of the pelvic vessels, and it is inconceivable 

 that any operation undertaken with care for the removal of the ovaries, 

 situated as they are high up in the abdominal cavity, could interfere with 

 this vessel. Care was also taken in our experiments to avoid injuring the 

 anastomotic branch of the ovarian artery, which passes along the Fallopian 

 tube to join the uterine. 



For this purpose in several of the experiments a lateral incision was made 

 over the ovary on each side, so as to obtain better access and interfere with 

 the mesovarium as little as possible by traction, a condition which is 

 unavoidable in removal of the ovaries by a mesial incision. Thus all dangers 

 of fallacy from vascular interference were avoided. 



A mesial incision is often unsatisfactory for the removal of ovaries, in 

 that the upper pole of the ovary may be left behind in dividing its superior 

 attachment, considerable traction being required to expose the organs freely. 



In the following experiments fully grown rabbits were used : — 



Experiment 1. — The ovaries were removed by a mesial incision, and the 

 animal killed after an interval of three and a-half months. Sections showed 

 that the uterine stroma had undergone considerable fibrosis and was reduced 

 in amount. The glands had almost entirely disappeared. The superficial 

 epithelium was, however, fairly normal, but degenerated in places, some 



* See the latter part of the present paper, where recent theories upon the nature and 

 importance of the uterine influence are discussed. 



