852 A MANUAL OF ANATOMY 



is due to the lateral distension and elevation of the viscus, the 

 ol)literated hypogastric itself lying along the outer wall of the 

 pelvis. For the structure and development of the bladder, see 

 Index. 



Vas Deferens in the Pelvis. — The vas deferens enters the abdomen 

 through the internal abdominal ring, where it lies on the inner side 

 of the other constituents of the spermatic cord. It then hooks 

 round the outer side of the deep epigastric artery, and, having 

 crossed the external iliac vessels from without inwards, it dips down 

 on the inner side of the external iliac vein. In this way it enters 

 the pelvis under cover of the peritoneum. It now passes backwards 

 and downwards upon the lateral wall, crossing the obliterated hypo- 

 gastric artery and ureter, both on the inner side. Thereafter it is 

 directed inwards to the inner aspect of the upper end of the 

 vesicula seminalis, whence it passes downwards and inwards, and 

 then vertically downv/ards upon the base of the bladder, where it 

 lies close to the inner side of the seminal vesicle. This part of the 

 vas deferens, which comes very near its fellow, is dilated and 

 sacculated, like the adjacent vesicula seminalis, and is known as 

 the ampulla. Close to the base of the prostate gland the saccula- 

 tions disappear, and the duct, having become very narrow, is 

 joined on the outer side at an acute angle by the duct of the seminal 

 vesicle, and so the common ejaculatory duct is formed, which will 

 be presently described. For the structure and development of the 

 vas deferens, see Index. 



Vesiculae Seminales. — These are two in number, right and left, 

 and lie between the base of the bladder and the rectum. They 

 are sacculated reservoirs for the seminal fluid, and each is conical, 

 being about 2 inches long, and about ^ inch broad at the widest 

 part. The broad end is free, and looks upwards and outwards. 

 It is covered posteriorly by the peritoneum which forms the recto- 

 vesical pouch, and anterior to it is the ureter, as that is about to 

 pass through the bladder. The upper ends of the two seminal 

 vesicles are wide apart, and the bottom of the recto-vesical pouch 

 descends between them for a short distance. The lower end of 

 each, which is narrow and free from sacculations, approaches its 

 fellow, the vasa deferentia intervening. This lower end represents 

 the duct, which, as stated, joins the vas deferens at an acute angle 

 close to the base of the prostate gland, and so gives rise to the 

 common ejaculatory duct. For the structure and development of 

 the vesiculae seminales, see Index. 



Common Ejaculatory Ducts. — ^These are two in number, right 

 and left. Each is formed by the union of the duct of the vesicula 

 seminalis with the vas deferens close to the base of the prostate 

 gland, and it is about i inch in length. The two ducts pass down- 

 wards and inwards through the prostate gland, between the middle 

 and lateral lobes, and each enters the lateral wall of the sinus 

 pocularis. Thereafter each duct terminates in a minute aperture, 

 which is situated either on the lateral margin of the opening of the 



