MALE ORGANS OF REPRODUCTION 493 



efferentes, which have much thinner walls. The lining epithelium of 

 the epididymis is of the tall, ciliated, simple columnar type with elon- 

 gated ovoid nuclei, a finely granular cytoplasm, and a group of non- 

 motile cilia which often adhere together to form a peculiar tuft or 

 cluster ('brush border'). At the base of the ciliated cells is an in- 

 complete layer of basal epithelium, whose flattened cuboidal elements 

 are wedged between the bases of the tall columnar cells. The two- 

 layered epithelium is thus of the pseudo-stratified type. The cells ap- 

 parently multiply largely by amitosis. 



The epithelium rests upon a cellular basement membrane, which is 

 supported by a connective tissue tunic of varying thickness. In addi- 

 tion to many elastic fibers, this coat contains a few smooth muscle 

 cells. The coils of the epididymis are firmly united into a solid mass 

 by means of the dense intervening connective tissue. They form the 

 whole of the globus minor and a considerable portion of the globus 

 major. When unraveled the duct of the epididymis measures about 

 twenty feet in length. 



The Ductus Deferens ( Vas Deferens) . This duct is a continua- 

 tion of the epididymis, whose course now becomes relatively straight. 

 It measures about eighteen inches in length. In this portion of the 

 excretory duct of the testis the lining epithelium soon loses its cilia, 

 and the basal cells become more prominent. Hence in the greater 

 portion of its course the ductus deferens is lined by tall, columnar, 

 non-ciliated epithelium, with low basal cells between the attached ends 

 of the columnar cells. 



The epithelium rests upon a fibro-cellular basement membrane, 

 which is supported by a fibrous tunica propria. This, in turn, passes 

 almost insensibly into the muscular coat which consists of two layers, 

 an inner circular and an outer longitudinal, both of which are highly- 

 developed. In the lower portions of the ductus deferens, a thin internal 

 layer of longitudinal muscle fibers is also found. The fibers of the 

 internal and middle circular layers are frequently less regularly ar- 

 ranged, in which case their oblique bundles interlace with one another 

 in a most intricate manner. The very thick, smooth muscular coat 

 and the relatively narrow lumen give this portion of the duct a firm 

 consistence and a cord-like feel. 



In its ampulla the dilated portion near its prostatic termination 

 the mucous membrane of the ductus deferens is more loosely attached 

 and the folds or rugae, which elsewhere are few in number, are here 

 very pronounced. The lumen of the ampulla is broad, but elsewhere 



