THE PROBLEM OF REJUVENATION 491 



and Kelker (1920) and of Voronoff (1923) may be mentioned 

 in this connection. Voronoff claims to have had excellent 

 results in many cases of transplantation of apes' testicles. 

 Two of his cases, men of 61 and 74 years of age, were observed 

 for about two years after the operation. Recuperation of 

 sexual potency and a very remarkable general improvement 

 are recorded. In other cases there was no success at all or only 

 a temporary or partial one. Voronoff is of the opinion that 

 testicular transplantation is indicated only in those cases where 

 the symptoms are conditioned by an hormonic insufficiency of 

 the testicle, and that no success will be attained when in- 

 sufficiency of other organs is involved. Thorek (1922) removed 

 a heterograft 7 months after the operation, and he stated 

 that the graft was histologically in a condition assuring normal 

 endocrine activity. Stanley and Kelker report that, according 

 to the statement of the oculist, a very marked improvement of 

 eyesight was obtained in a man of 54 after testicular homoio- 

 transplantation. Stanley (1922) claims also to have treated 

 senility successfully by implantation of testicular substance 

 obtained from various mammals. In the latter cases there 

 could only have been an effect from the resorbed hormones, 

 as the testicular substance was introduced by pressing it out 

 of a syringe. 



In women, Bumm and Sippel (1923) obtained good results 

 in certain cases of precocious menopause and senility by 

 ovarian homoio transplantation. 



There has been much discussion on the question whether 

 "rejuvenation" really occurs after ligature or transplantation. 

 Since the changes characteristic of old age take place throughout 

 all the organs , and since senility is caused not merely by the 

 disfunction of one organ or of a certain group of organs 

 (Lipschutz, 1915), it is clear at the outset that in as far as 

 rejuvenation might be induced by an improvement in the 

 functional capacity of a certain organ, this rejuvenation could 

 be only a partial or a restricted one. Further, it must be taken 

 into consideration that the changes which the cells undergo 

 owing to age are in general irreversible ones, pigmentation and 

 cellular atrophy, and finally sclerosis taking place. But on 

 the other hand, the experiments on animals with transplanta- 

 tion and ligature of the vasa deferentia leave no doubt that 

 symptoms of senility may be checked to a certain degree, and 



