GENITAL ORGANS OF- THE MALE. 



629 



enlargement, the ampulla (Figs. 407, 408), beyond which, at the 

 base of the prostate, it narrows and joins with the duct of the 

 vesicula seminalis, thus forming the ejaculatory duct (Fig. 409). 

 The total length of the duct is about 60 cm. 



Vesicula Seminalis (Fig. 410). This structure is a diverticulum 

 from the vas deferens, and glands exist in its mucous membrane 

 which is covered with non-ciliated columnar epithelium. Some 

 authorities regard it as a storehouse for the semen, while others do 

 not regard this as one of its functions. Bohm and Davidoff state 

 that " spermatozoa are, as a rule, not met with in the seminal 



FIG. 411. Section of penis, bladder, etc.: 1, symphysis pubis; 2, prevesical 

 space; 3, abdominal wall; 4, bladder; 5, urachus; 6, seminal vesicle and vas 

 deferens ; 7, prostate ; 8, plexus of Santorini : 9, sphincter vesicae ; 10, suspensory 

 ligament of penis ; 11, penis in flaccid condition ; 12, penis in state of erection ; 13, 

 glans penis ; 14, bulb of urethra ; 15, cul-de-sac of bulb, a, Prostatic urethra ; 6, 

 membranous urethra; c, spongy urethra (Testut). 



vesicles." The vas deferens and especially its ampulla serve to 

 retain the semen until ejaculated. A considerable amount of fluid 

 is added to the semen by the secretion of the mucous membrane 

 lining the vesicula seminalis, and this is probably its most im- 

 portant function. The ejaculatory ducts discharge into the urethra 

 at its prostatic part. 



The prostate gland and Cowper's glands contribute also to the 

 formation of the semen. 



Semen. The semen or seminal fluid consists of secretions from 



