352 SPLANCHNOLOGY. 



fascia. It varies in size, and consists of three lobes ; a middle 

 and two lateral ones ; the middle one lies on the posterior part 

 of the neck of the bladder and the superior surface of the 

 urethra ; in old 'animals this lobe may become enlarged, and 

 pressing on the urethra cause retention of urine. It is enclosed 

 in a dense fibrous capsule, which is continuous with the pelvic 

 fascia. It is pale, reddish -grey, and very friable, consisting of 

 glandular and muscular tissue, containing numerous small 

 follicular pouches, which end in elongated canals ; these again 

 unite to form a number of excretory ducts, which open in a 

 depression called the prostatic sinus, situated at either side of the 

 verumontanum. The follicles are united together by areolar 

 tissue, supported by prolongations of the capsule. The canals 

 and the follicles are lined with columnar epithelium. 



The prostate gland is supplied with blood by the vesico- 

 prostatic artery, its veins forming the prostatic plexus. 



COWPER'S GLANDS. 



Cowper's glands, called also in veterinary anatomy the lesser 

 prostates, are a pair of small bodies, situated on either side of 

 the membranous portion of the urethra, above the ischial arch, 

 covered by Wilson's muscle. They are of a reddish-yellow 

 colour, and dense in their structure, consisting of several minute 

 lobules held together by investing cellular tissue. They resemble 

 the prostate gland in their ultimate structure, being compound 

 racemose or aggregated glands, and terminate in the urethra by 

 a row of minute openings on each side. 



URETHRA. 



The urethra is a tube which extends from the neck of the 

 bladder to the glans penis in the male, and from the bladder to 

 the vulva in the female. In the latter it is simply an excretory 

 passage for the urine, but in the male it transmits also the 

 seminal fluid. It consists of two layers ; an internal mucous 

 one, continuous with that of the bladder internally, and the 

 covering of the glans penis externally ; and an external layer 

 consisting of fibrous tissue, with muscular fibres. 



It is divided into prostatic, membranous, and spongy portions. 

 The prostatic, very short, is the most dilatable part of the canal, 

 commencing at the neck of the bladder. It passes through the 



