THE PROBLEM OF REJUVENATION 



489 



of the numerous successful experiments of Wilhelm were 

 extremely striking (Figs. 139-142). Wilhelm has performed six 

 similar experiments out of which five gave the same positive 

 result. The improvement lasted in one case about 10 months. 

 Romeis (1921) made a unilateral ligature of the vas deferens 

 on one old rat, while the second testicle was removed. He 

 states that there was an increase of weight and the animal 



Fig. 142. — "Rejuvenation" of senile do^, i8 years old. 

 operation. Weight 48 kgr. — From Wilhelm. 



Six months after 



became livelier, but there was no recuperation of sexual 

 activity. The hair became less rough, but the hairless patches 

 remained as they were. There was an increase of the prostate, 

 but Romeis claims that this was due to a distention of the 

 prostatic gland by its secretion and that the glandular cells 

 were atrophic. A single partly negative experiment, however, 

 can hardly be made the basis for a discussion of the whole 

 problem in the way the author attempts to do, especially in 

 view of the numerous experiments of Steinach on rats 

 published previously and of the positive experiments of Sand 



