64 BIOLOGY AND SOCIAL PROBLEMS 



course of time assumed all the male secondary 

 sexual characteristics and exhibited sexual 

 desire. On examining its transplanted testes, 

 however, it was found that all the reproduc- 

 tive cells had disappeared and that the inter- 

 stitial cells had crowded in and taken their 

 place. For this reason it is believed that the 

 hormones which are given out by the repro- 

 ductive glands, and which serve to excite the 

 development of the secondary sexual charac- 

 teristics, are not the products of the germ cells 

 proper, the egg cells and sperm cells, but 

 come from the interstitial cells which are in 

 no wise concerned with reproduction. 



Enough is known concerning operations 

 and transplantations in the human being to 

 justify the conclusion that the results obtained 

 by Steinach on the lower mammals will be 

 found to apply with full force to man. The 

 complete removal of the ovaries from a woman 

 is always followed by a premature menopause. 

 In the case of a woman who had been for two 

 years without ovaries and who during that 

 period had not menstruated, the successful 

 grafting into her body of a live ovary from 

 another woman was followed by a return of 

 menstruation and sexual desire. The profound 



