260 



THE VISCERA. 



sac, enveloped in the membranes or tunics described when 

 treating of the scrotum. Each is attached to the dorsal wall 

 of its peritoneal pouch by a mesenteric fold. The testis is sur- 

 rounded by the visceral layer of the tunica vaginalis propria, 

 and within this, by a dense fibrous covering, the tunica albu- 

 ginea, which sends septa into its interior. Within the fibrous 

 covering it is made up of numerous coils of seminiferous tubules 

 which are readily seen by the naked eye. 



The epididymis (Fig. 1 10, c) is the beginning of the 

 efferent duct of the testis. It appears as a flat band with a broad 

 rounded end which lies on the medial surface of 

 the testis at its cranial end (<). From this 

 point it passes about the cranial end of the testis 

 from its medial to its lateral surface, forming 

 thus a semicircle with the convexity ventrad. 

 Thence it passes as a narrower band (c] along 

 the dorsal side of the testis, laterad of the sus- 

 pending mesentery, to the caudal end of the 

 testis (d}. At the caudal end of the testis it 

 is enlarged, passes from its lateral to its medial 

 surface, and turns at the same time craniad to 

 become continuous with the vas deferens (e]. 



The enlarged cranial end is the caput epi- 

 FIG io TESTIS didymis (^) ; the enlarged caudal end the cauda 

 a. testis; b, caput epididymis (d}. The whole epididymis is 

 epididymis; c, epi- encased in a tough fibrous covering similar to 



didymis; 0, cauda . ,, 



epididymis; e, vas that of the testis. 1 he fibrous covering (albu- 

 deferens; /, sper- gjnea) of the testis and that of the epididymis 



matic cord. J 



are connected by fibrous tissue. Within the 

 fibrous covering the head of the epididymis is made up of tubules 

 which pass from the testis into its end : these are the vasa 

 efferentia testis. The vasa efferentia unite within the caput 

 into a single vessel which passes in a very tortuous course to 

 the cauda: Its numerous windings form the cauda, from the 

 end of which it passes craniad as the vas deferens (e). 



The vas deferens (Fig. no, e; Fig. in, c) is a slender 

 tube much convoluted at its beginning. It passes from the 

 cauda epididymis (d} along the mesenterial fold of the testis 



