592 



GENITAL ORGANS OF THE BOAB 



vided into lobules. Many of the tubules are extremely wide (as much as 2 mm. in diameter), and 

 are beset with bay-like extensions and short, wide branches. These axial spaces of the lobules are 

 succeeded by the efferent ducts. The ca^'ities are lined by a single layer of columnar cells. The 

 secretion is thick and turbid, and has an acid reaction. 



The prostate consists of two parts, as in the ox. The body is about an inch 

 (2.5 cm.) wide, and overiies the neck of the bladder and the urethra at their junc- 

 tion. It is concealed by the vesiculse seminales. The pars disseminata forms a 

 layer which surrounds the pelvic part of the urethra, and is covered by the urethral 

 muscle, except dorsally. 



The uterus masculinus is small, and appears to be inconstant. 

 The bulbo-xorethral glands are very large and dense. They are somewhat 



cylindrical, and lie on either 

 side of and upon the posterior 

 two-thirds of the pelvic ure- 

 thra. "^ 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 

 width. They are partially 

 covered with a layer of stri- 

 ated muscle (M. bulbo-glan- 

 dularis), and have a lobulated 

 surface. Each gland has a 

 large excretory duct which 

 leaves at the deep face of the 

 posterior part, 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 bulbo-urethral glands may 

 be only about an inch long in such 

 subjects. 



The penis resembles in 

 general that of the ox. The 

 sigmoid flexure is, however, 

 prescrotal. The anterior part 

 has no glans, and is spirally 

 twisted, especially in erection. 

 The external 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. The retractor penis arises from 

 the third and fourth sacral segments; its two parts run backward and a little 

 ventrally on each side of the rectum to the perineum, where they reach the urethral 

 surface of the penis; they end on the ventral curve of the sigmoid flexure of the penis. 



' AMien hardened in situ, they are in great part three sided, with rounded edges. They are in 

 contact with each other to a considerable extent and cover the urethra dorsally and laterally. The 

 lurethral muscle partly covers their lateral surfaces. 



Fig. 527. — Genital Oegaxs of Boah. 

 a, Testicle; 6, epididymis; f, ductus deferens; d, spermatic artery; 

 e, vesiculaseminalis; e', excretory ducts of vesiculse; /, body of prostate; 

 g, bulbo-urethral gland; h, tu-inary bladder; i, urethral muscle; k, 

 bulbo-cavernosus muscle; 1, penis; I', sigmoid flexure of penis; I", 

 spiral anterior part of penis, exposed by slitting open prepuce ; m, ori- 

 fice of preputial pouch; n, retractor penis muscle. The vesiculse sem- 

 inales are drawn outward to show the structures which, in the natural 

 position, are covered by them. (EUenberger-Baum, Anat. d. Haustiere.) 



