EPIDIDYMIS VAS DEFEKEXS. 



971 



long, and when unrolled, each is found to consist of a single coiled duct, 

 varying from six to eight inches in length, and the diameter of which 

 gradually decreases from the testis to the epididymis (Huschke). Opposite 

 the globus major these separate efferent vessels open, at intervals which in 

 the unravelled tube are found to be about three inches in length, into a 

 single caual or duct, the intervening and subsequent convolutions of which 

 constitute the epididymis itself. 



Fig. 679. INJECTED TESTICLE, Fig. 679. 



EPIDIDYMIS, AND VAS DEFERENS 

 (from Kolliker after Arnold). 



a, body of the testicle ; 6, lo- 

 bules ; c, vasa recta ; d, rete vas- 

 culosum ; e t vasa efferentia ; /, 

 coni vasculosi ; g, epididymis ; A, 

 vas deferens ; z, vas aberrans ; m, 

 branches of the spermatic artery 

 passing to the testicle and epidi- 

 dymis ; n, ramification in the 

 testis ; o, deferential artery ; p, 

 its union with a twig of the sper- 

 matic artery. 



The canal of the epididy- 

 mis is disposed in very nu- 

 merous coils, and extends 

 from the globus major down- 

 wards to the globus minor or 

 tail, where, turning upwards, 

 it is continued on as the vas 

 deferens. When its com- 

 plicated flexuosities are un- 

 rolled, it is found to be 

 twenty feet and upwards in 

 length. The smallest wind- 

 ings are supported and- held 

 together by fine areolar 



tissue ; but, besides this, numerous fibrous partitions are interposed 

 between larger masses of the coils, which have been named the lobes of 

 the epididymis, the general direction of which is across that body. The 

 canal of the epididymis is, at its commencement, about -^th of an inch 

 in diameter, but diminishing as it proceeds towards the globus minor, it is 

 about -g^th of an inch, after which it again increases in size, and becomes 

 less tortuous as it approaches the vas deferens. Its coats, which are at first 

 very thin, become thicker in its progress. 



The vasa efferentia and the tube of the epididymis differ from the other 

 portions of the ducts of the testis in their epithelium being ciliated. In the 

 epididymis the cells are greatly elongated, in the vasa efferentia they are 

 shorter ; in the lower part of the epididymis the cilia disappear (Becker, 

 corroborated in the human subject, by Kolliker). 



VAS DEFERENS. 



The vas deferens, or excretory duct of the testis, is a hard round tube, 

 which forms the continuation upwards of the convoluted canal of the epi- 

 didymis. It commences at the lower end of the epididymis, and, at first 



