43 8 THE SPERMATIC DUCTS. [SECT. I99. 



§ 199. Vasa Deferentia ; Vesiculce Seminales ; Accessory Glands ; 

 Organ of Giraldes. — The spermatic ducts, vasa deferentia, are 

 cylindrical canals, 1 line to 1^ in average width, with walls \'" to ■§■"* 

 in thickness, and with a cavity J'" to \'" in diameter. They are 

 composed, on the outside, of a thin fibrous coat, next to this a 

 layer of smooth muscular fibres, and, most internally, a mucous 

 membrane. The muscular coat, 0"^>'" to o'6"' in thickness, 

 possesses an external thick layer of longitudinal fibres, a middle 

 layer of equal thickness, whose fibres run transversely and ob- 

 liquely, and an inner thin layer, which amounts to only one-fifth 

 of the entire thickness of the muscular coat ; this coat consists of 

 rigid and pale fibre-cells, measuring up to o'i'" in length, 0-004'" 

 to o"oo6'" in average breadth, intermingled with some connective 

 tissue and a few very pale elastic fibrillse. The mucous membrane, 

 0-12'" in thickness, is white, puckered longitudinally, and is provided 

 with numerous reticulated depressions of various sizes in the last 

 or broadest segment of the duct. Its outer two-thirds are whiter, 

 and contain one of the densest networks of elastic fibrils that I 

 know of; whilst, internally, this is replaced by a clearer, thinner 

 layer of connective tissue, indistinctly fibrillated, and containing 

 nuclei. Upon this layer of the mucous membrane rests a simple 

 stratum of pavement-epithelium, composed of cells 0'005'" to 

 0"oo8"' in size, which invariably contain brownish pigment- 

 granules in some number ; these impart a yellowish colour to the 

 inner surface of the mucous membrane. . The vessels of the sper- 

 matic ducts are very distinct in the external fibrous coat, though 

 they also penetrate into the muscular and mucous coats, and form, 

 in both, loose networks of capillaries, o - oo3'" to 0'005'" in width. 

 According to Swan (Nerves of the Human Body, pi. v. 82, pi. vi. 81), 

 the nerves of the spermatic duct in the pelvic cavity are numerous 

 but delicate, and are connected with the lateral and middle nerves 

 of the bladder and rectum, as well as with the hypogastric plexuses. 

 I have likewise seen these nerves, and have found them to contain 

 fine fibres and fibres of Remah, but have not been able to trace 

 them into the interior. 



The ductus ejaculatorii and the vesicuke seminales appear to he 

 similar in their construction to the spermatic ducts, the vesicular 

 being, as is well known, nothing but crecal appendages of the vasa 

 deferentia, furnished with wart-like tubular, or even ramified pro- 

 cesses. The ejaculatory ducts present in their upper part the same 

 muscular structure as the spermatic duct, only that their walls are 

 more delicate. Towards the prostate gland, their coats become 



