MALE GENITAL ORGANS OF THE PIG 



505 



The vesiculae seminales are exceedingly large, and extend into the abdominal 

 cavity. They are three-sided pyramidal masses, are in apposition with each other 

 medially, and cover the posterior part of the bladder and the ureters, the vasa 

 deferentia, the body of the prostate, and the anterior part of the urethra. They 

 are pale pink in color, distinctly lobulated and glandular in structure, and contain 

 large alveoli, but no central cavity. There are two excretory ducts which open into 

 the urethra close to the vasa deferentia; the two ducts frequently unite. 



In the adult boar the vesicula? are about five to six inches (ca. 12 to 15 cm.) long, two to 

 three inches (ca. 5 to 8 cm.) wide, 

 and one and a half to two inches 

 (ca. 4 to 5 cm.) thick; they weigh 

 about 6 to 8 ounces each. 



The prostate consists of 

 two parts, as in the ox. The 

 body is about an inch (2.5 

 cm.) wide, and embraces the 

 neck of the bladder and the 

 urethra at their junction dor- 

 sally and laterally. It is con- 

 cealed by the vcsiculie sem- 

 inales. The pars disseminata 

 forms a layer which surrounds 

 the pelvic part of the urethra, 

 and is covered by the urethral 

 muscle. 



The uterus masculinus is 

 small. 



The bulbo-urethral (Cow- 

 per's) glands are very large and 

 dense. They are somewhat 

 cylindrical, and lie on either 

 side of and upon the pos- 

 terior two-thirds of the pelvic 

 urethra. In a large boar they 

 are about five inches (ca. 12 

 cm.) in length and an inch or 

 more (ca. 2.5 to 3 cm.) in 

 diameter. They are partially 

 covered with a layer of stri- 

 ated muscle (M. ischio-glandu- 

 laris), and have a lobulated 

 surface. Each gland has a 

 large excretory duct which 

 leaves at the posterior ex- 

 tremity, perforates the dorsal wall of the urethra at the ischial arch, and opens in 

 a cul-de-sac covered by a fold of mucous membrane. 



It is to be noted that these accessory glands are very small in animals which have been 

 castrated early. 



The penis resembles in general that of the ox. The sigmoid flexure is, how- 

 ever, prescrotal. The anterior portion has no glans, and is spirally twisted, 

 especially in erection. The urethral orifice is slit-like and is situated ventro- 

 laterally, close to the pointed extremity. The penis in the adult boar measures 

 about 18 to 20 inches (ca. 45 to 50 cm.) in length. Its muscles resemble those of 

 the bull; the bulbo-cavernosus is very strong but short. 



Fig. 404. — Genital 0ro.\n8 of Boar. 



o, Testicle; b, epididymis; c,vas deferens; d, spermatic artery; 

 e, vesieula seminalis reflected to show the body of the prostate, /; e', 

 excretory ducts of vesiculcp; g, bulbo-urethral (Cowper's) gland; h, 

 urinary bladder; i, urethral muscle; A-, bulbo-cavernosus muscle; I, 

 penis; Z', sigmoid flexure of penis; /", spiral anterior part of penis, ex- 

 posed by slitting open prepuce; m, orifice of preputial pouch; n, re- 

 tractor penis muscle. (EUenberger-Baum, Anat. d. Haustiere.) 



