ORGANS OF REPRODUCTION 



837 



and narrowed, and joins with the duct of the vesicula seminalis to form a 

 common ejaculatory duct. The walls of the vas deferens are composed of 

 fibrous and muscular tissue, which is lined by a mucous membrane with 

 columnar epithelium. 



The vesiculce seminales are two elongated sacculated bodies, placed ex- 



FIG. 212. 



FIG. 213. 



FIG. 212. The Base of the Male Bladder, with the Vesicuise Seminales and Prostat Jland. 

 (After Haller.) 1, the urinary bladder; 2, the longitudinal layer of muscular fibres; 3, >pi i pros- 

 tate gland ; 4, membranous portion of the urethra ; 5, the ureters ; 6, bloodvessels ; 7, lef^.S, right 

 vas deferens ; 9, left seminal vesicle in its natural position ; 10, ductus ejaculatorius of the left 

 side traversing the prostate gland; 11, right seminal vesicle injected and unravelled; 12,13, 

 blind pouches of vesiculse ; 14, right ductus ejaculatorius traversing the prostate. 



FIG. 213. a, lobules ; b, vasa recta ; c, mediastinum ; d, vasa efferentia ; e, body of epMidymis ; 

 /, rete testes ; g, globus minor ; h, vas deferens ; i, tunica albuginea and its interlobu ; ar reflec- 

 tions ; I, globus major. 



B 



\ 



A, Spermatozoa from the Human Vas Deferens. (After Kolliker.) 1, magnified 350 diameters ; 

 2, magnified 800 diameters ; a, from the side ; b, from above. B, Spermatic Cells and Spermatozoa 

 of the Bull undergoing Development. (After Kolliker.) 450; 1. 1, spermatic cells, with one or 

 two nuclei, one of them clear; 2, 3, free nuclei, with spermatic filaments forming; 4, the fila- 

 ments enlongated and the body widened ; 5, filaments nearly developed. . 



ternal to the vasa deferentia. The structure of the seminal vesicles is simi- 

 lar to that of the vasa deferentia, consisting of a fibre-muscular wall lined 

 with a mucous membrane, which is covered by granular, nucleated, polygonal 

 epithelium cells. These organs serve as receptacles for the seminal fluid 

 secreted by the testes, and at the same time produce a secretion of their own 



