1907.] Correlation of the Ovarian and Uterine Functions. 393 



January 20 it was killed when quite full grown and in perfect condition- 

 Weight, 3020 grammes. The ovaries were extremely well developed and 

 contained numerous discharged follicles. 



Experiments 4 ami 5. — In each experiment the uterus was removed from 

 a very young rabbit, excepting the cervix, and the rabbit killed after several 

 months (in the one case after eight months and in the other after 10 months).. 

 CEstrus was noticed in both cases after the animals had reached maturity. 

 The ovaries in both cases were normal, those of one animal containing large 

 follicles, and those of the other (which had been with the buck) recently 

 ruptured follicles. 



Experiment 6. — The uterus was removed entire from a very young rabbit 

 on May 17. Weight, 470 grammes. In August the animal was observed to 

 be ill and on August 28 was killed. The ovaries had undergone development, 

 since the operation and were normal in histological appearance. 



Experiment 7. — The uterus and Fallopian tubes were completely removed 

 from a young rabbit on December 9. The rabbit was killed on April 3, when 

 the ovaries were found to be normal and to contain many follicles. 



In four experiments on rats the uterus was removed entire in the month 

 of July. Two of the rats were killed in January, when the ovaries sho wed- 

 no indications of degeneration. The other two were killed in April, the- 

 ovaries being large in size and containing many protruding follicles. 



On the other hand, marked uterine degeneration has been recorded in rats- 

 after the removal of the ovaries for shorter intervals of time (Marshall and 

 Jolly, 1907). 



Further, in the case of a ferret in which the uterus was removed, the- 

 histological appearance of the ovaries was normal after three months, when 

 the animal unfortunately died. The interval which had elapsed, however, 

 was probably too short to admit of the deduction of definite conclusions. 



It may be concluded as a result of these experiments that the growth and 

 development of the ovaries are in no way dependent upon the presence of 

 the uterus. Such a conclusion is no doubt in opposition to some of the 

 clinical evidence, but it is one which on phylogenetic grounds might be 

 expected, since the uterus is an organ which came into existence compara- 

 tively recently in the course of vertebrate evolution, whereas the ovary is 

 common to all Metazoa. 



It has been shown, further, that oestrus and coitus may occur after the 

 complete removal of the uterus. Whether under such a condition the 

 other generative organs undergo any of the changes which normally 

 characterise the procestrum was not determined, since such changes are in. 

 any case difficult to detect in rabbits. 



