THE MALE ORGANS OF GENERATION 



2 9 I 



vas deferens, forming on each side the ejaculatory duct, 

 which opens into the prostatic urethra. 



Semen. The semen, or seminal fluid, consists of secre- 

 tions from the testes, seminal vesicles, prostate, and other 

 glands connected with the male genital tract. The es- 

 sential elements are the spermatozoa, or male reproductive 



FIG. 159. Seminal vesicles and vasa deferentia, posterior view : i, 

 Bladder; 2, prostate; 3, 3', seminal vesicles; 4, 4', vasa deferentia; 5, ejacu- 

 latory ducts ; 6, 6', ureters ; 7, 7, perivesicular cul-de-sac of peritoneum ; 8, 

 interdeferential triangle, in direct relation with the rectum, from which it is 

 separated only by the prostatoperitoneal aponeurosis. The two crosses 

 (+ +) indicate the points at which the ureters disappear in the vesical wall 

 (Testut). 



cells (Fig. 161), which are secreted by the testes. The 

 spermatozoa are about 50 /^ in length and consist of a 

 body and tail, the latter serving to give to the cell the 

 power of moving about. 



Impregnation. The function of the spermatozoon 

 is to produce impregnation or fertilization of the ovum. 

 To accomplish this it must come in contact with the 



