THE MALE REPRODUCTIVE ORGANS. 



213 



of the epididymis. The vasa eflferentia and coni vasculosi possess 

 a stratified columnar epithelium, the inner cells bearing long ! 



ilia t"nic f^rMtn^lnim rocf-c r\r\ o 



cilia ; this epithelium rests on a 

 robust basement-membrane, out- 

 side of which lies a fibrous coat 

 strengthened in many places by 

 a circular layer of involuntary 

 muscle. 



The greatly convoluted tube of 

 the epididymis has a similar 

 wall, composed of stratified cili- 

 ated columnar epithelium, a 

 well-marked membrana propria, 

 augmented by fibrous tissue, and 

 a ring of pale muscle ; this mus- 

 cular layer gradually thickens on 

 approaching the vas deferens, in 

 whose wall it becomes a tunic of 

 considerable thickness. 



The structure of the spermatic 

 duct, or vas deferens, closely re- 

 peats the arrangement of the tube 

 of the epididymis. A stratified 

 non-ciliated columnar epithe- 

 lium, separated from the tunica 

 propria by a well-defined basement- 

 membrane, covers the mucosa; 

 outside of the latter lies a sub- 

 mucous layer of laminated con- 



FIG. 258. 



Section through lower part of epididymis 

 of child, showing general structure : a, fibro- 

 serous envelope ; b, sections of convoluted tube 

 of epididymis ; c, vas deferens ; d, intertubular 

 tissue ; e, blood-vessels. 



nective tissue, which is embraced 



by the muscular tunic, consisting of an inner circular and an 



outer longitudinal layer. 



The ampulla possesses the same coats as the vas deferens, although 

 in the former the several layers are somewhat thinner. The sem- 

 inal vesicle, likewise, consists of a mucous coat, lined by stratified 

 columnar epithelium, a submucous and a muscular tunic. Small, 

 often branched, tubular glands occur within the mucous membrane 

 of the ampulla and the seminal vesicle. The ejaculatory duct, 

 formed by the union of the vas deferens and the duct of the seminal 

 vesicle, contains a single layer of columnar epithelium, supported 

 by the fibrous tunica propria ; a thin submucosa, together with a 

 slightly developed inner circular and an outer longitudinal stratum 

 of muscle, completes the wall of the duct. 



Connected with the epididymis are certain atrophic appendages 



