476 ANDREW T. EASMUSSEN 



Adding still more interest to this subject is the serious consid- 

 eration which it is receiving by clinicians.' While during the 

 last few years, surgeons have performed a number of grafting 

 operations on men with some success, a rather unexpected re- 

 sult has been reported by Morris ('16), who found that testic- 

 ular grafts caused an undeveloped testis to enlarge and become 

 apparently normal. This is mentioned here only because it 

 indicates the practical importance of advancing our knowledge 

 concerning the endocrine function of the testis. 



Since all the evidence in favor of the secretory function of the 

 interstitial cells of the testis, as well as of the ovary, is indirect, 

 there are those who hesitate (c.f. Kingsbury, '14, W. Blair Bell, 

 '16) in ascribing to these cells the function of producing a spe- 

 cific substance of 'hormonic' or 'chalonic' action in the organism. 

 Bell is especially emphatic as may be seen from the following 

 quotation (p. 145) : 



Again, it is extremely interesting to note how erroneous has been 

 the view, generally held, that the interstitial cells of the ovary and 

 testis are responsible for the secondary sex characteristics. For many 

 years I have contended that the gonads play but a subservient part; 

 and this is emphatically demonstrated .... by the fact that 

 in the testes of tubular partial hermaphrodites with feminine secondary 

 characteristics, . . . . , the interstitial cells are always devel- 

 oped to a remarkable extent to a degree which is rarely seen even in 

 the undescended testis and never in the normal .testis. These cells 

 cannot, therefore, be responsible for the secondary characteristics. 



The evidence supporting the secretory function of the inter- 

 stitial cells has been derived from various sources, the most 

 important of which are: the general histological character of 

 the interstitial cells (epithelioid) ; various pathological con- 

 ditions of the testis and abnormal sex development, such as 

 the various forms of hermaphrodism and cryptochism, with the 

 corresponding histological character of the tissues of the tes- 

 tis; effects of castration, vasectomy and transplantation in 

 man and laboratory animals; exposure of the testis to the influ- 

 ence of X-rays; injection of testicular extracts; degree of de- 



^ See, for example, On abnormalities of the endocrine function of the gonads 

 in the male, Lewellys F. Barker, Amer. Journ. Med. Sci., 1915, vol. 149, p. 1. 



