476 INTERNAL SECRETIONS 



in a bird with normal hormonic activity, it appears that the 

 accumulation of fat and the changes occurring in the metabolism 

 after castration cannot be due to lack of those sex hormones 

 upon which the development of other sex characters depends. 

 Whereas a small testicular fragment suffices for normal masculi- 

 nization in the copulatory and genital apparatus and the neuro- 

 psychical sex characters, the state of the metabolism seems to 

 depend upon the quantity of testicular tissue present in the 

 body. Evidently the metabolism is affected by the quantita- 

 tive level of the spermatogenetic processes. Is this influence 

 an hormonic one? Or is this influence due to absorption by 

 the testicle of different substances necessary for spermato- 

 genesis? The latter explanation seems to me more likely. 



The following is another example showing how complicated 

 the relations between the sex gland and other parts of the 

 organism may be. It was stated by Owen that the retractor 

 muscles of the penis of the gelding become transformed into 

 sclerotic tissue. The question has been examined histo- 

 logically by Retterev (1915), who came to the conclusion that 

 this transformation of the muscles is due simply to atrophy by 

 inactivity, since the gelding, unlike the stallion, does not expel 

 the penis when urinating. It seems possible that other castra- 

 tion effects might be explained similarly; for instance, the 

 diminution of the corpora cavernosa penis (see p. 6), since 

 sexual desire and erection diminish or disappear after castra- 

 tion. On this view one might understand why the corpora 

 cavernosa penis and the corpus cavernosum urethrae behave 

 differently after castration, the function of the latter being 

 independent of sexual activity. The following observation is 

 also not without interest [Lipschutz, 1923). In our experiments 

 when there was operative interference with one testicle, such 

 as removal of the greater part of it and retention only of a 

 fragment above the cauda epididymidis, no testicular secretion 

 could enter the latter. Now we found in these experiments 

 that the cauda was much diminished, though there was a 

 normal hormonic activity of the testicular fragment, and 

 though, as in some experiments in which the second testicle 

 was left intact, the cauda was normally developed on that side. 

 There can be no doubt that in these experiments the under- 

 development of the cauda epididymidis was caused not by 

 absence of hormones, but by decreased distension or b}^ atrophy 



