THE UTERUS MASCULINUS—-THE BULBO-URETHRAL GLANDS 579 
two lateral lobes and a connecting isthmus. The lateral lobes, right and left 
(Lobus dexter et sinister), are somewhat prismatic in form, and are directed forward, 
laterally, and somewhat upward. The deep surface of each lobe is concave and 
partly embraces the corresponding vesicula seminalis. The dorsal surface is con- 
cave and is in relation with the rectum. The ventral surface is convex and lies 
on the obturator internus muscle and fat. The apex is pointed and lies near the 
posterior end of the superior ischiatic spe. The isthmus is a thin, transverse 
band, about four-fifths of an inch (ca. 2 em.) wide. It lies over the junction of the 
bladder with the urethra, the uterus masculinus, the terminal parts of the ductus 
deferentes, and the ducts of the vesiculee seminales. Dorsally it is partly covered 
by fibers of the urethral muscle. 
Structure.—The prostate is enclosed in a capsule of fibrous tissue, with an 
admixture of unstriped muscle fibers. The gland substance is divided into sphe- 
roidal or ovoid lobules by trabeculee which consist to a large extent of unstriped 
muscle. Each lobule is traversed by an axial duct, which gives off numerous 
tubular branches and these ramify further in the lobule. The tubules are thickly 
beset with saccular diverticula, giving the gland a branched, tubulo-alveolar struc- 
ture. The ducts and tubules are lined with cubical or columnar epithelium. The 
prostatic secretion (Succus prostaticus) is milky in appearance and has a character- 
istic odor. There are fifteen to twenty prostatic ducts (Ductus prostatici) on either 
side, which perforate the urethra and open lateral to the colliculus seminalis (Fig. 
521). The blood-supply is derived from the internal pudic artery. 
The surface of the prostate is commonly tuberculate in old subjects, and amyloid bodies 
and calcareous concretions may be found in it. 
THE UTERUS MASCULINUS 
The uterus masculinus or utriculus prostaticus is a foetal remnant of variable 
size and form, which is situated centrally on the posterior part of the dorsal surface 
of the bladder. When well developed, it consists of a median flattened tube, some 
three or four inches (ca. 7.5 to 10 em.) long, and about half an inch (ea. 1 to 1.5 em.) 
wide, the anterior part of which lies in the genital fold and gives off two slender 
processes or cornua; the latter curve forward and outward in the fold a variable 
distance, being sometimes traceable as far as the anterior end of the ampulla of the 
ductus deferens. The posterior extremity of the tube passes under the isthmus of the 
prostate, and opens into the urethra on the summit of the colliculus or joins a duct 
of a vesicula seminalis or has a blind end. It has a muscular coat and a mucous 
lining. In many cases it consists merely of a very small central tubule with a blind 
_ anterior end, or a band, not sharply marked off from the adjacent tissue; in other 
cases it cannot be recognized. It is a remnant of the ducts of Miiller and the 
homologue of the uterus and vagina. 
THE BULBO-URETHRAL GLANDS 
The bulbo-urethral glands (Glandulew bulbourethrales)! are two in number, 
and are situated on either side of the pelvic part of the urethra close to the ischial 
arch (Fig. 577). They are covered by the urethral muscle, from which bundles 
enter the larger trabecule of the gland. They are ovoid in form, somewhat de- 
pressed dorso-ventrally, and their long axes are directed obliquely forward and 
outward. In the stallion they may measure nearly two inches (ca. 4 em.) in length, 
and about an inch (ca. 2.5 em.) in width. In the gelding they are about the size of 
an average hazel-nut. 
Structure.—They resemble the prostate in general structure, but the inter 
1 Also termed Cowper’s glands. 
