THE UROGENITAL SYSTEM. 261 
n its medial side, to the spermatic cord (Fig. 111, a). It 
zaves the spermatic cord at the internal inguinal ring and, 
urving over the ureter (Fig. 111, 6), bends craniad and 
pproaches the vas deferens of the opposite side dorsad of the 
eck of the bladder (Fig. 111, f). The two vasa deferentia 
ass caudad together as far as the cranial border of the pubis. 
Chere they enter the prostate gland (), pierce the dorsal wall 
if the neck of the bladder, and open close together on the inner 
urface. The two openings are separated by a slight elevation, 
he veru montanum. 
The Urethra (Fig. 111, #).—The urethra is the common 
irinogenital duct which is formed by the union of the neck of 
he bladder (/) and the vasa deferentia (c) dorsad of the cranial 
vorder of the pubis. It extends thence to the end of the penis. 
t is divided into three portions. 
1. The prostate portion is the commencement of the 
wethra; it is surrounded by the prostate gland (g). 
2. The membranous portion (#) extends from the prostate 
ortion to a point between the crura of the penis. This por- 
ion is surrounded by the thick compressor urethre muscle, so 
hat its wall appears much thicker than it really is. 
3. The spongy portion (pars cavernosa) extends along the 
‘entral side of the penis to its end in the groove between the 
orpora cavernosa penis. At its beginning is an enlargement 
ormed by the bulbocavernosus muscle. This is known as the 
ulbus urethre. The walls of the spongy portion are thick 
nd vascular and form the corpus cavernosum urethre or 
orpus spongiosum. At its end the corpus cavernosum urethra 
3; greatly enlarged and forms the glans penis (7). 
Glands of the Urethra.—1. The prostate (Fig. 111, g) isa 
ilobed gland lying on the dorsal wall of the urethra and sur- 
ounding the ends of the vasa deferentia (¢). It opens into the 
rethra at its beginning by numerous small ducts visible to the 
aked eye on the inner surface of the urethra. 
2. The bulbourethral or Cowper’s glands (Fig. 111, 7).— 
‘here are two bulbourethral or Cowper’s glands, one on either 
ide of the bulbus of the urethra between the ischiocavernosus 
nd bulbocavernosus muscles. Each has a covering of muscle- 
