864 THE GENEEATIVE APPARATUS. 



the latter by its outer face, and to the accelerator and ischio-cavernous 

 muscles by its inner face. Above, it is lost around the termination of the 

 rectum ; below, it expands between the thighs ; it is seen insinuating itself, 

 to the right and left, between the ischio-cavernous and semimembranosus 

 muscles, to be attached to the ischiatic tuberosity. 



4. The Glands annexed to the Urethra. 



A. PROSTATE (Fig. 402, 8) This single and symmetrical gland is 

 situated at the commencement of the urethra, and lies across the neck of the 

 bladder. A constriction in the middle divides it into two voluminous 

 lateral lobes inclining slightly forward. Its upper face corresponds to the 

 rectum, through the medium of the cellular, tissue at the bottom of the 

 pelvic cavity. Its inferior face, moulded on the neck of the bladder, 

 embraces it above and laterally, and is closely attached to it ; it covers the 

 terminal extremity of the deferent and ejaculatory ducts, and the neck of 

 the vesiculae seminales. 



STRUCTURE. The tissue composing this gland forms a number of 

 communicating cells, which are larger in the Ass than the Horse ; in these 

 is collected a quantity of viscid fluid (succus prostaticus) secreted by their 

 walls, and which is ejected into the urethra by the two rows of orifices 

 arranged on the sides of the veru montanum. These communicating cells 

 are nothing more than conglomerate glands, which are distributed in a 

 stroma of connective tissue and unstriped muscular fibres. 



B. COWPER'S GLANDS.; In Veterinary anatomy, these are frequently 

 named the small prostates. They are two globular bodies, denser in texture 

 than the prostate gland, but otherwise the same in organisation, and are 

 situated on each side of the urethra, in the perineal region, above the ischial 

 arch ; they are completely enveloped by a somewhat thick fleshy cover- 

 ing, formed by the fibres of Wilson's and the ischio-urethral muscles 

 (Fig. 402, 11). 



The fluid they secrete is thrown into the urethral canal by numerous 

 orifices disposed in several rows. It has the same physical properties as 

 that of the prostate, and both are poujed into the urethra in abundance 

 immediately before ejaculation; the expulsion of the semen is by this 

 means facilitated. 



5. The Corpus Cavernosum. 



The corpus cavernosum is an erectile stalk, which forms the base of the 

 penis and supports the urethra ; it is situated between the thighs, prolonged 

 beneath the abdomen, attached behind to the ischial arch, and terminates in 

 front by a free. extremity, which is received into the erectile enlargement 

 named the glans penis. 



External conformation. Flattened on both sides, this body offers for 

 study two lateral faces, two borders, and two extremities. The faces are 

 plane, and present no interesting features. The superior, or dorsal border, is 

 the thickest, and is rounded. The inferior is channeled throughout its 

 extent by a deep furrow which lodges the urethra. The posterior extremity 

 is bifurcated, the two branches constituting the roots (corpora or crura) of the 

 penis ; they are fixed to the ischial arch, one to the right, the other to the left, 

 and are covered by the two ischio-cavernosus (erector penis] muscles : short, 

 thick, and strong masses intersected by numerous tendinous fibres, and partly 

 concealed by the semimembranosus muscles. These erector penis muscles 



