THE REPRODUCTIVE ORGANS 79 



reports a successful case of transplantation of the homoplastic 

 variety. The ovaries from one woman were grafted into a 

 second, and the latter gave birth to a child four years later. 



Knauer was apparently the first to report successful auto- 

 plastic transplantation in animals. The ovaries were detached 

 from their normal position and grafted upon the mesometrium 

 or into the abdominal wall. A certain part of the grafted organ 

 degenerated ; the rest of it gave rise to ova which were capable 

 of fertilization. Atrophy of the uterus, an invariable result of 

 castration, was prevented if successful transplantation of an 

 ovary had been effected. Several other authors have obtained 

 similar results. Some writers have reported that the offspring 

 resulting from fertilization of ova from grafted ovaries indicate 

 a " foster-mother " influence. Thus ovaries have been trans- 

 planted from hen to hen. Such fowls laid eggs which were 

 duly hatched, and the chicks partook of certain of the foster- 

 mother's characters. 



Transplanted ovaries remain normal for a time, except that 

 the germinal epithelium becomes absorbed. Sometimes 

 degeneration occurs and the stroma may remain normal while 

 the follicles disappear or are replaced by corpora lutea. 

 Transplanted ovaries show the same cyclical changes as normal 

 organs, i.e., ovulation occurs in them. Autoplastic trans- 

 plantation is more easily carried out than homoplastic, and the 

 most successful cases are those in which two animals from the 

 same litter are employed. 



But ovarian grafts and their effects on the uterus are not 

 permanent. Sooner or later degeneration takes place in the 

 grafted organ and atrophy of the uterus takes place. Accord- 

 ing to A. Louise M'llroy, the rate of degeneration varies with 

 the site of implantation, the more vascular the site, the longer 

 the persistence of the graft. The corpora lutea first undergo 

 a hyaline change and infiltration of leucocytes. Cystic 

 degeneration overtakes the follicles, though the interstitial 

 cells may persist for some time longer. Professor 'M'llroy 

 considers that it is the interstitial cells which control the 

 nutrition of the uterus, since atrophy occurs only when they 

 are degenerated. The experiments so far carried out indicate 

 that a grafted ovary may remain functional for a year or more. 



Experiments carried out by Steinach show that if ovaries 

 are grafted into young male guinea-pigs, the mammary gland 



