860 



TBE GENERATIVE APPABATUS. 



STEUOTURE.-Tlie yas deferens is formed, internally, by a -^e^y ^^e 

 mucous membrane covered witb cylindrical epithelium, and to this is added 

 ^^^ZZTcontractile and ^Jihrcus tunic. The contractile layer is formed 

 S three planes of unstriped fibres : the deep and superficial planes have 

 lonStudinal and the middle circular fibres. It is, proportionately, very 

 S at the dHated portion of the duct, and it is to its great density that 

 the vas deferens owfs its consistence as a hard rigid cord The mucous 

 membrane of the pelvic dilatation has tubular and acinous glands. 



Fig. 402. 



2. The Vesiculm Seminales and Ejaculatory Duds. (Fig. 326.) 



The vesiculcB seminales are two oval pouches whose volume varies vdth 



their contents, and which are placed m the 

 pelvic cavity, above the bladder and the vas 

 deferens. Each vesicula has a middle portion 

 and two extremities. The middle portion is 

 enveloped by a loose abundant cellular 

 tissue, and is in relation with the rectum 

 above, and below with the bladder and vas 

 deferens. 



The anterior extremity is the largest, 

 and forms a rounded cul-de-sac, covered in 

 almost the same manner as the bladder by 

 the peritoneum, which at this point fur- 

 nishes a very small triangular frsenum (the 

 recto-vesical fold) that unites the two vesi- 

 culsB. The posterior extremity tapers to a 

 narrow neck, which passes beneath the pros- 

 tate gland, and joins at a very acute angle 

 the terminal extremity of the vas deferens, 

 to constitute the ejaculatory duct. 



The walls of this pouch are composed 

 of three membranes : an internal mucous, a 

 middle muscular, and an external fibrous. 

 The mucous layer is continuous with that 

 of the ejaculatory ducts, and is very thin, 

 delicate, and follicular. It shows numerous 

 folds, which disappear with distention of the 

 duct. The middle layer evidently belongs 

 to the class of muscular membranes ; its 

 identity with that of the bladder is complete. 

 , Left vas deferens ; 1', Its pelvic At the bottom of the cul-de-soc it gives off 

 dilatation ; 2, 2, The same on the general fasciculi, which radiate on the ex- 

 right side ; 3 4, Vesicular seminales ; ^ ^ ^ ^-^ peritoneum. (In addi- 

 5, The third vesicula : 6, berous ., , ,, ^ . . . ^ ,„ 

 layer uniting the vasa deferentia; tion to these, the vesiculffi and vasa dete- 



7, That comprised between the two rentia have a muscular covering whose fibres 

 vesicula:; 8, Prostate gland; 9, ^re arranged in a longitudinal and trans- 

 verse direction, the latter being the most 

 superficial. This muscular layer being con- 

 tinuous over the vesiculre seminales and vas 

 , , , i deferens, when it contracts, will compress 

 glands enveloped by that muscle; and shorten these ; consequently, it has been 



IJ, IZj Ischio-cavernosus muscle; - - ■»■ . y ' 



13, ■ ■ 



SUPEEIOE VIEW OF THE PELVIC POE- 

 TION OF THE VASA DEFERENTIA, 

 VESICULA SEMINALES, PROSTATE 

 GLAND, COWPEB'S GLANDS, AND THE 

 INTRAPELVIC PORTION OP THE 

 URETHRA. 



Bladder seen through the serous 

 fold of the vasa deferentia ; 10, 

 Membranous or intrapelvic portion 

 of the urethral canal, covered by 

 Wilson's muscle; 11, 11, Cowper's 



, 1^. iscnio-cavernosus muscle; -, ,, .7^7, 



, Accelerator urinai muscle. named the compressor vesiculce ct ductus 



