736 GENERATION AND DEVELOPMENT. 



The mucous membrane lining the vesiculse seminales, 

 like that of the gall-bladder, is minutely wrinkled and set 

 with folds and ridges arranged so as to give it a finely 

 reticulated appearance. The rest of their walls is formed, 

 chiefly of a layer of organic muscular fibres, from which 



Fig. 214.* 



they ^derive contractile power for the expulsion of their 

 contents. 



To the vesiculse seminales a double function may be 

 assigned ; for they both secrete some fluid to be added to 



* Fig. 214. Dissection of the base of the bladder and prostate gland,, 

 showing the vesiculee seminales and vasa deferentia (from Haller). a, 

 lower surface of the bladder at the place of reflexion of the peritoneum ; 

 Z>, the part above covered by the peritoneum ; i, left vas deferens, ending 

 in e, the ejaculatory duct ; the vas deferens has been divided neari, and 

 all except the vesicle portion has been taken away ; s, left vesicula 

 seminalis joining the same duct ; s, s, the right vas deferens and right 

 vesicula seminalis, which has been unravelled ; p, under side of the 

 prostate gland ; m, part of the uretha ; , u, the ureters (cut short 

 near 7i), the right one turned aside. 



