808 MALE ORGANS OF GENERATION. 



posite the bases of the cones, the efferent vessels open at narrow intervals into 

 a single, duct, which constitutes, by its complex convolutions, the body and 

 globus minor of the epididymis. When the convolutions of this tube are 

 unravelled, it measures upwards of twenty feet in length, and increases in 

 breadth and thickness as it approaches the vas deferens. The convolutions are 

 held together by fine areolar tissue, and by bands of fibrous tissue. A long 

 narrow tube, the vasculum aberrans of Haller, is occasionally found connected 

 with the lower part of the canal of the epididymis, or with the commencement 

 of the vas deferens, and extending up into the cord for about two or three 

 inches, where it terminates by a blind extremity, which is occasionally bifur- 

 cated. Its length varies from an inch and a half to fourteen inches, and some- 

 times it becomes dilated towards its extremity : more commonly, it retains the 

 same diameter throughout. Its structure is similar to that of the vas deferens. 

 Occasionally, it is found unconnected with the epididymis. 



The Vas Deferens, the excretory -duct of the testis, is the continuation of the 

 epididymis. Commencing at the lower part of the globus minor, it ascends 

 along the posterior and inner side of the testis and epididymis, and along the 

 back part of the spermatic cord, through the spermatic canal, to the internal 

 abdominal ring. From the ring it descends into the pelvis, crossing the exter- 

 nal iliac vessels, and curves round the outer side of the epigastric artery: at the 

 side of the bladder, it arches backwards and downwards to its base, crossing 

 outside the obliterated hypogastric artery, and to the inner side of the ureter. 

 At the base of the bladder, it lies between that viscus and the rectum, running 

 along the inner border of the vesicula seminalis. In this situation, it becomes 

 enlarged and sacculated ; and, becoming narrowed, at the base of the prostate, 

 unites with the duct of the vesicula seminalis to form the ejaculatory duct. 

 The vas deferens presents a hard and cord-like sensation to the fingers; it is 

 about two feet in length, of cylindrical form, and about a line and a quarter in 

 diameter. Its walls are of extreme density and thickness, measuring one-third 

 of a line; and its canal is extremely small, measuring about half a line. 



Fig. 440. Base of the Bladder, with the Vasa Deferentia and Vesiculse Seminales. 



Riylt Eja 



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In structure, the vas deferens consists of three coats: 1. An external, or cel- 

 lular coat; 2. A muscular coat, which is thick, dense, elastic, and consists of 

 two longitudinal, and an intermediate circular layer of muscular fibres; 3. An 

 internal, or mucous coat, which is pale, and arranged in longitudinal folds; its 

 epithelial covering is of the columnar variety. 



