THE UROGENITAL SYSTEM 263 
middle line beneath the pelvic symphysis. This band divides 
distally, and its halves ensheath the glans and thus form a sup- 
port of the penis. 
The penis is formed by three bodies, the two corpora 
cavernosa penis and the single corpus cavernosum urethre 
(corpus spongiosum). 
The corpora cavernosa penis (Fig. 111, 7). Each is a 
cylindrical sheath of dense fibrous tissue within which are 
trabeculz separating blood-sinuses. Each corpus cavernosum 
is attached by the one pointed end to the caudal border of the 
ramus of the ischium near the symphysis. From their attach- 
ments the corpora cavernosa approach one another, forming 
the crura of the penis. They become closely united by their 
medial surfaces and pass thus to the free end of the penis where 
their somewhat pointed distal ends are imbedded in the 
glans (7). A groove is left between the corpora cavernosa on 
the dorsum of the penis, and there is a second groove on the 
ventral side. In the latter groove lies the urethra. 
The corpus cavernosum urethre is the spongy portion of 
the urethra which lies in the groove on the ventral surface of 
the penis, between the corpora cavernosa penis. It becomes 
greatly enlarged at the distal end of the penis, forming the 
glans (}. A small bone (os penis) is imbedded in the distal 
end of the penis. 
B. FEMALE GENITAL ORGANS (Fig. 112).—The urinal 
organs of the female are like those of the male. The neck (£) 
of the bladder is, however, much longer, extending almost to 
the border of the ischiatic ramus. The urethra is consequently 
short. 
The genital organs consist of the ovaries (c) (the organs 
which produce the eggs), the oviducts or uterine. tubes (ce) 
(Fallopian tubes), which receive the eggs from the ovaries; a 
bifid uterus (f and z) in which the ova undergo their develop- 
ment, and a vagina (#z) which leads from the uterus to its 
junction with the neck of the bladder. 
The neck of the bladder (4) unites with the vagina to form 
the urogenital sinus (7) which is very short, leads to the 
external opening, and is comparable to the male urethra. 
