344 INTERNAL SECRETIONS 



known to Kolliker that weak alkaline solutions can stimulate 

 the movements of the spermatozoa. Recently Amantea and 

 Krzyskowsky (1920 b) repeated these experiments using different 

 physiological solutions, and again showed how spermatozoa 

 can remain alive in salt solutions for a very considerable 

 period, though in the secretion of the sex gland itself the 

 normal movement is more prolonged. A more exact investi- 

 gation of the question of the hydrogen ion concentration most 

 suitable for mammalian spermatozoa has been made by Wolf 

 (1921a), who succeeded in keeping spermatozoa of the rabbit 

 in movement for nine days. But there was no evidence that 

 these spermatozoa were capable of fertilization (1921 b). 



In view of these considerations one might assume that the 

 secretion of both glands has some influence on the spermatozoa ; 

 this would not be contrary to the above-mentioned experi- 

 ments of Iwanoff. It is possible that sterility as observed 

 after removal of the vesicles and of the prostate is due to the 

 fact that the spermatozoa have lost the great vitality by which 

 they are normally able to swim from the vagina to the tubes 

 where fertilization takes place. This would explain why ferti- 

 lization occurred in the experiments of Iwanoff, where the 

 seminal fluid obtained from the epididymis was directly 

 introduced into the female passages. The question is a much 

 more complicated one than was formerly supposed. It seems 

 very likely that the vitality of the spermatozoa depends not 

 only upon the secretion of the vesicles and of the prostate, 

 but also on that from other accessory glands. According to 

 Stigler and R. Pollitzer (1918) motility and resistance of sper- 

 matozoa depend also on a secretion of the epididymis; they 

 concluded from their experiments that there were in the 

 secretion of the epididymis some stimulating substances not 

 present in the secretion of the vesicles. 



The question of the secretory function of the epididymis, 

 has been studied also histologically by various observers in such 

 animals as the lizard, in which there is a periodical spermato- 

 genesis and a secretory activity of the epididymis beginning dur- 

 ing spermatogenesis and highly developed during the passage 

 of the spermatozoa through the excretory ducts of the gonad. 

 The question has been dealt with again by Courrier (1920 a), 

 a pupil of Bouin. In the bat a great quantity of spermatozoa 

 remain in the epididymis during the whole of hibernation. 



