12 THE GENITAL GLANDS 



FUNCTIONS OF THE TESTIS. 



The most obvious function of the testis, of course, 

 is to produce spermatozoa, which it continues to do 

 well on into old age. 



The testis, however, contains other secretory cells 

 between the tubules, sometimes called the cells of 

 Leydig, and to these is attributed the production of 

 an internal secretion. It is not uncommon for one 

 or both testes to fail to descend (cryptorchism), and 

 in bilateral cases the individual is nearly always 

 sterile, but the secondary sexual characters are 

 usually preserved. On microscopical examination 

 the tubules are little developed, but the interstitial 

 cells of Leydig appear to be normal. 



It has been much debated whether the failure to 

 descend is the cause or the consequence of the failure 

 to develop, and on the answer to this question 

 depends the surgical treatment ; if the first is true, 

 it is highly desirable to find some operative procedure 

 which will ensure the testis a permanent resting- 

 place in the scrotum, but the evidence goes to show 

 that this does not lead to proper growth of the gland, 

 so we must conclude that descent fails because it is 

 not worth while for the gubernaculum to bring 

 down a defective organ. 



When the testes on both sides are removed after 

 puberty, the consequences are sterility, atrophy of 

 the prostate gland, and in a few cases in old men 

 mental impairment. The secondary sexual characters 

 are not lost, and it is very doubtful if the dotage 

 which has sometimes followed is really due to loss of 

 any internal secretion or nervous influence ; most 



