VESICUL.E SEMINALES. 



In structure the prostate gland is composed of ramified ducts, termi- 

 nating in lobules of follicular pouches, which are so closely compressed 

 as to give to a thin section of the gland a cellular appearance beneath 

 the microscope. It is pale in colour and hard in texture, splits easily in 

 the course of its ducts, and is surrounded by a plexus of veins which 

 are enclosed by the strong fibrous membrane with which it is invested. 

 Its secretion is poured into the prostatic portion of the urethra by 

 fifteen or twenty excretory ducts. The urethra in passing through 

 the prostate lies one-third nearer to its upper than its lower surface. 



VESICUL^E SEMINALES. 



Fig. 177*. 



Upon the under surface 

 of the base of the bladder, 

 and converging towards the 

 base of the prostate gland, 

 are two lobulated and some- 

 what pyriform bodies, about 

 two inches in length, the 

 vesiculae seminales. Their 

 upper surface is in contact 

 with the base of the blad- 

 der; the under side rests 

 upon the rectum, separated 

 only by the recto-vesical 

 fascia; the larger extremi- 

 ties are directed backwards 

 and outwards, and the 

 smaller ends almost meet 

 at the base of the prostate. 

 They enclose between them 

 a triangular space, which is 

 bounded posteriorly by the 

 recto-vesical fold of perito- 

 neum, and which corre- 

 sponds with the trigonum vesicse on the interior of the bladder. Each 

 vesicula is formed by the convolutions of a single tube, which gives off 

 several irregular csecal branches. It is enclosed in a dense fibrous 

 membrane, derived from the pelvic fascia, and is constricted beneath 

 the isthmus of the prostate gland into a small excretory duct. The 



* The posterior aspect of the male bladder ; the serous covering is removed 

 in order to shew the muscular coat. 1. The body of the bladder. 2 Its fun- 

 dus. 3. Its inferior fundus or base. 4. The urachus. 5, 5. The ureters. 

 6, 6. The vasa deferentia 7, 7. The vesiculse seminales. The triangular area, 

 bounded by the vasa deferentia and vesiculae seminales on either side, a dotted 

 line above, and the numeral 3 below, is the space corresponding with the tri- 

 gonum vesicse. It is this part of the bladder which is pierced, in puncturing 

 the bladder through the rectum. The dotted line forming the base of this tri- 

 angular area marks the extent of the recto-vesical fold of the peritoneum. 



