THE TEOSTATE GLAXD. 429 



side, from the symphysis pubis and anterior ligament of the bladder, 

 and embrace the sides of the ]irostate. Tliis part of each levator ani 

 is occasionally separated from the rest of the muscle by areolar tissue, 

 and has been named leralor prostatcc. 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 en- 

 closes the first part of the urethra. The canal runs nearer to the anterior 

 than to the posterior 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 colliculus seminalis and the openings of 

 the seminal and prostatic ducts, as will be afterwards more particu- 

 larly described. The common or ejaculatory seminal ducts, which ])ass 

 forwards from the vesicula; semiiiales, also traverse the lower part of 

 the prostate, enclosed in a special hollow part of the gland, and open 

 into the urethra; and in the middle, close in front of these, is the 

 prostatic utricle. 



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

 •which, placed laterally, and meeting behind in the posterior notch, and 

 continuous in front of the urethra, are of equal size ; the third, or 

 middle lobe, is a smaller pyriform or three-sided mass, intimately 

 connected with the other two, and fitted in between them and the neck 

 of the bladder and adjacent part of the urethra. "When prominent it 

 corresponds to the elevation in the urinary bladder called uvula. The 

 separation between the lobes of the prostate, which is little marked 

 in the natural state, becomes often much more apparent in disease. 



Structure. — The prostate gland is covered externally by a dense 

 fibrous ccat, which is continuous with the recto-vesical fascia, and with 

 the posterior layer of the triangular ligament. Adams describes the 

 fibrous capsule as divisible into two layers, between Avhich the pro- 

 static plexus of veins is enclosed. The glandular substance is asso- 

 ciated with a large quantity of plain muscular tissue, which forms 

 the principal part of the stroma of the organ. This muscular tissue 

 forms an external layer below the fibrous capsule, and extends every- 

 where through the glandular substance : there is also a strong layer 

 of circular fibres continuous posteriorly with the sphincter Vesicre, 

 and in front with the thin layer surrounding the membranous part 

 cf the urethra. The part of the prostate in front of the urethra is 

 almost entirely muscular, and in the hinder part the muscular sub- 

 stance is in greatest quantity near the bladder. The glandular sub- 

 stance is spongy and yielding ; its colour is reddish grey, or sometimes 

 of a brownish hue. It consists of numerous small saccules, or terminal 

 vesicles, opening into elongated tubes, which unite into a smaller 

 number of excretory ducts. The epithelium is columnar both in the 

 vesicular terminations and in the canals. In the upper part of the 

 gland the acini are small and hemispherical ; in the middle and lower 

 parts the tubes are longer and convoluted at their ends. The capillary 

 blood-vessels spread out as in other similar glands on the ducts and 

 clusters of vesicles, and the different glandular elements are united by 

 areolar tissue, and supported by processes of the deep layer of the 

 fibrous capsule and muscular stroma. The ducts open by from twelve 

 to twenty or more orifices upon the floor of the urethra, chiefly in thq 



