REPRODUCTIVE ORGANS IN THE MALE. 279 



organ the testicle has a fine reticulum of connective 

 tissue that is associated with the capsule or tunica 

 albuginea. This reticulum consists of areolar tissue 

 that not only intervenes between the lobules, but 

 interlaces between the seminiferous tubules. Blood 

 and lymph vessels are everywhere associated with 

 this tissue. In addition to ordinary connective- 

 tissue cells, there is associated with this reticulum 

 patches of cells that re- 

 semble epithelium and 

 have yellowish granules 

 or pigment. These are 

 called interstitial cells, 

 and, like the areas of 

 Langerhans of the pan- 

 creas, are supposed to se- 

 crete products regularly 

 absorbed by the blood. 

 We can postulate a pos- 

 sible function of these 

 cells when we consider 

 the function of the testi- 

 cle and its influence on 



Fig. 



209. Sustentacular 

 cells ~( cells of Sertoli) of the 

 guinea-pig (chrome-silver me- 

 thod) ; profile view: c, c, Depres- 

 sions in the sustentacular cells 

 due to pressure from the sper- 

 matogenic cells; d, basilar por- 

 tion of sustentacular cells 

 (Bohm and Davidoff). 



the body as a whole. 



(i) Physiologically the testis exerts a marked influ- 

 ence on the development of the body. (2) It is ac- 

 tively engaged in the production of spermatozoa. 

 (3) It is essential for the act of copulation. 



Early castration in domestic animals is a striking 

 evidence of the influence the testicle exerts upon 

 development. The change manifest is both physi- 

 cal and mental. As the infantile testis does not 



