FORM OF THE PROSTATE GLAND. 953 



or by two grooves, which meet ID front, and correspond with the course of 

 the seminal ducts, as well as mark the limits of the lateral lobes in this 

 situation : it is in close apposition with the rectum, immediately in front 

 of the bend from the middle to the lower or anal part of that viscus, 

 where the surface and posterior border of the gland can be felt by the 

 finger introduced into the intestine. The sides are convex and prominent, 

 and are covered by the anterior portions of the levatores ani muscles, which 

 pass back on each side, from the symphysis pubis and anterior ligament 

 of the bladder, and embrace the sides of the prostate. This part of 

 each levator ani is occasionally separated from the rest of the muscle by 

 areolar tissue, and has been named levator prostatce. The base of the gland 

 is of considerable thickness, and is notched in the middle : its apex is 

 turned towards the triangular ligament. As already stated, the prostate 

 encloses the commencement of the urethra. The canal runs nearer to the 

 upper than to the under surface of the gland, so that in general it is about 

 three lines distant from the former and four or five from the latter ; but 

 it frequently varies greatly in this respect. The prostatic portion of the 

 urethra is about an inch and a quarter long, and is dilated in the middle ; 

 it contains the verumontanum and the openings of the seminal and prostatic 

 ducts, and will be afterwards more particularly described. The common 

 seminal ducts, which pass forwards from the vesiculse seminales, also traverse 

 the lower part of the prostate, enclosed in a special canal, and open into the 

 urethra. 



Fig. 669. 



Fig. 669. LONGITUDINAL MEDIAN SECTION OF THE LOWER PART OF THE BLADDER 

 AND PROSTATE GLAND (after E. H. Weber). 



17, inner surface of the urinary bladder ; u r, opening of the right ureter, from which 

 a slight elevation runs down to the neck of the bladder ; p, upper part of the prostate ; 

 p', the so-called middle lobe ; p", the right lateral lobe ; u, the utricle or sinus pocularis ; 

 d, the right ejaculatory duct; v d, vas deferens ; v s, vesicula seminalis. 



This gland is usually described as consisting of three lobes, two of which, 

 placed laterally and separated behind by the posterior notch, are of equal 



