THE PERINEUM, MALE. 421 



shaped, one and one-half inches across the base and one 

 and one-quarter inches in vertical extent, placed with its 

 base uppermost and the apex below. There is a notch at 

 the base dividing the gland into two lobes. Into this notch 

 the vasa deferentia and seminal vesicles converge to unite 

 into the common ejaculatory ducts which traverse the 

 prostate downward and forward to open into the floor of 

 the prostatic urethra. The gland is enclosed in a capsule 

 derived from the rectovesical fascia, upon which it rests. 

 At the apex of the gland, at the place where the urethra 

 issues, the fibres of the levator ani muscle are wanting (the 

 muscle being behind the gland), and at this point the recto- 

 vesical fascia becomes continuous with the deep layer of 

 the triangular ligament. 



Relations. Above : The bladder, vasa deferentia, seminal 

 vesicles. Behind : Rectum separated only by a thin layer 

 of rectovesical fascia. Below : The rectovesical fascia and 

 deep layer of the triangular ligament. In front : Pubo- 

 prostatic ligaments. Laterally : Capsule derived from the 

 rectovesical fascia, and separating it from the levator ani 

 muscle. The prostatic venous plexus encloses the gland, 

 being between it and its capsule. Into the front of the 

 plexus the deep vein of the penis empties. 



The Lower Portion of the Rectum. For the upper 



part, see page 504. Fig. 84. Diag. 28. 

 The lower portion of the rectum extends from the tip of 

 the coccyx to the anus, a distance of one and one-half 

 inches. This part of the rectum curves downward and 

 backward ; consequently, in introducing a tube into the rec- 

 tum it should first be pointed forward and upward or toward 

 the umbilicus, then it may be carried backward toward the 

 sacrum. In children this precaution should be followed. 



