42 LEO LOEB. 



3. Various writers, especially Bouin and Ancel, concluded that 

 the interstitial cells of the testicle are responsible for the develop- 

 ment of sexual desire in the male. Our observations seem to 

 confirm this view. The complete absence of spermatogonia in 

 the tubules, together with the marked development of the inter- 

 stitial gland was accompanied by the presence of marked mani- 

 festations of sexual instinct. 



4. Bouin and Ancel, Steinach (7, 8) and Tandler and Grosz 

 not only ascribe to the interstitial gland the function to cause 

 chemically those nervous changes which find expression as sexual 

 desire, but the additional task of enhancing the development of 

 the male sexual characters, of allowing the full development of 

 prostate, penis, seminal vesicle, and of suppressing the develop- 

 ment of the female secondary characters. Our observations 

 apparently contradict these conclusions. In our case, the very 

 marked development of the interstitial gland was accompanied 

 by the absence of penis, seminal vesicles (and presumably of 

 prostate), and on the other hand was associated with a very 

 marked development of the mammary gland. The latter re- 

 sembled a proliferating breast, a "proliferating gland" such as 

 Dr. Hesselberg and the writer found it in certain stages of the 

 sexual cycle in the female guinea pig (9). Our observations prove 

 that the presence of a very strongly developed interstitial gland 

 is perfectly compatible with the existence of certain female, and 

 with the absence of certain male secondary sexual characters. 

 A priori two interpretations of this fact are possible : 



(a) The interstitial gland of the testicle has not a specific 

 function in the sense assumed especially by Bouin and Ancel 

 and Steinach. (&) The interstitial gland is specifically "male 

 enhancing" in its function, but the end effect does not only de- 

 pend upon this specific action of the interstitial gland, but also, 

 and primarily so, on the system on which it acts. We have reason 

 for assuming that in a certain respect an individual can be com- 

 pared to a more or less sensitive balance in his or her sexual 

 potentialities and that different individuals of a certain species 

 differ in the resting point of their sexual equilibrium (10, n, 12, 

 13, 14). Without the interference of hormones which are pro- 

 duced by the gonads, the point of equilibrium in some individuals 



