THE MALE GENITAL ORGANS. 



365 



hardly capable of demonstration. The convoluted tubules are 

 separated from each other by a small amount of connective tissue, 

 in which, in addition to the vessels, nerves, etc., are found peculiar 

 groups of large cells containing large nuclei, and known as interstitial 

 cells. Nothing definite is known regarding the significance of these 

 cells ; but they are probably remains of the Wolffian body. Reinke 

 (96) found repeatedly crystalloids of problematic significance in the 

 interstitial cells of the normal testis. 



The stratified epithelium of the convoluted tubules changes in 





Fig. 293. From section of human testis, showing convoluted seminiferous 



tubules. 



the tubuli recti to an epithelium consisting of a single layer of short 

 columnar or cubical cells resting on a thin basement membrane. 



The canals of the rete testis (Haller) are lined by nonciliated 

 epithelium, which varies in type from flat to cubical. Communicat- 

 ing with the rete testis is a blind canal, the vas aberrans of the rete 

 testis, lined with ciliated epithelium. 



The vasa efferentia are lined partly by ciliated columnar and 

 partly by nonciliated cubical epithelium. The two varieties form 

 groups which alternate, giving rise to nonciliated depressions, 

 which represent gland-like structures (Schaffer, 92), but do not 



