The =scrotum= is situated a short distance from the anus, and is not so
sharply defined from the surrounding parts as in the other animals.
The =testicles= are very large and are soft in texture. Their long axis
is almost vertical, the free border being posterior and the tail of the
epididymis dorsal. The mediastinum testis is well developed. The
epididymis is closely attached to the testicle and the tunica vaginalis;
the tail is specially large.
The =spermatic cord= is necessarily very long (20 to 25 cm. in a boar of
medium size). The =vas deferens= in its testicular part is flexuous, and
is closely attached to the tunica vaginalis; it forms no ampullæ. The
=cremaster externus= is well developed, and extends to about the middle
of the scrotal part of the tunic.
The =vesiculæ 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 vesiculæ 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 dorsally and laterally. It is concealed by the
vesiculæ seminales. 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= (Cowper’s) =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 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 striated
muscle (M. ischio-glandularis), and have a lobulated surface. Each gland
has a large excretory duct which leaves at the posterior extremity,
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.
[Illustration: