CHAPTER IX 



THE TESTICLE AND THE OVARY AS ORGANS OF 

 INTERNAL SECRETION 



" Da muss sicli manches Rathsel losen, 

 Doch manches Riithsel kniipft sicli aucli." 



GOETHE. 



THE principal evidence supporting the theory that the ovary 

 and testicle are organs of internal secretion is derived from the 

 experimental study of the effects produced, firstly, by removing 

 these organs, and, secondly, by transplanting them to abnormal 

 positions in the body. Experiments of such a kind clearly 

 demonstrate the influence of the ovary and testicle upon the 

 growth and development of the other generative organs, and 

 upon many of the secondary sexual characters. They indicate, 

 moreover, that the nature of this influence is chemical rather 

 than nervous. Certain further evidence, which is less satis- 

 factory in character, has been obtained from experiments on 

 the injection of ovarian and testicular extracts. 



THE CORRELATION BETWEEN THE TESTIS AND THE 

 OTHER MALE ORGANS AND CHARACTERS 



It has already been recorded (p. 239) that the removal of 

 the testes in adult life brings about a gradual atrophy of the 

 prostate gland. It has also been shown that this operation, if 

 performed prior to puberty, prevents the development of the 

 prostate, whereas division of the vas deferens and the abolition 

 of sperm production have no arresting influence. 1 One-sided 

 castration produces no effect, the retention of a single testis 

 being sufficient to maintain the functional activity of both 



1 Wallace (C ), " Prostatic Enlargement," London, 1907. It is shown also, 

 that vasotomy has no influence on the growth and activity of the prostate. 



