330 INTERNAL SECRETIONS 



see again that the results of the transplantation experiments 

 in which male and female hormones were simultaneously 

 present in the same organism were also very conflicting; and 

 I think that in these latter experiments the disparity can be 

 explained only on quantitative lines. 



Basing his position on Herrmann's and Stein's results, 

 Harms (1922) drew attention to the fact that there may 

 be signs of castration, though interstitial cells are present in 

 the degenerated testicle. He declared these experiments to 

 afford further evidence for the conclusion that the interstitial 

 cells are not the hormone-producers in the testicle. The 

 absence of agreement between Fellner and Herrmann on the 

 question of the behaviour of the sex characters of injected 

 male animals shows clearly enough that the conclusion of 

 Harms is without justification. Harms has evidently over- 

 looked the disparity between Fellner and Herrmann, as he 

 quotes Fellner's experiments in support of his assumption. 



It seems at first thought that the changes obtained by Fellner 

 and Herrmann in their experiments correspond with those of 

 normal puberal development and early pregnancy. It may 

 be pointed out that the transformation of the mammary 

 gland caused by injection of the extract into the male animal 

 corresponds with that observed by Steinach and others after 

 transplantation of ovaries into the male organism. But have 

 we any guarantee that all these changes, as described by Fellner 

 and Herrmann, are really caused by a definite chemical 

 substance? This is not very probable. As we have already 

 pointed out, it is most likely that the internal secretion of the 

 sex gland does not consist of one hormone, but rather of many 

 different hormones. 



An experimental comparison between the action of extracts 

 of the corpus luteum and that of the hilum ovarii was under- 

 taken by Itagaki (19 17) in the laboratory of Schafer. He 

 stated that the action of these extracts upon the movements 

 of the living uterus of the rat are antagonistic to one another, 

 the first causing a distinct increase of tone, the second causing 

 inhibition. But the uterus of other animals reacts differently; 

 in the rabbit, cat and guinea pig extracts of both the corpus 

 luteum and the hilum produce an increase of tone. Sometimes 

 however the extract of corpus luteum may produce inhibition. 

 Itagaki suggests that this difference of effect is possibly due 



