DEVELOPMENT OF THE UROGENITAL ORGANS. 113 
-what cylindrical portions, the corpora cavernosa clitoridis. These represent the 
corpora cavernosa of the male, and diverge from one another at the root of the clitoris 
to form the crura clitoridis. A suspensory ligament (ligamentum suspensorium clito- 
ridis) passes from the fibrous coat of the body of the clitoris to the symphysis pubis. 
The glans clitoridis is a small mass of erectile tissue which is fitted over the 
pointed end of the body. It possesses, like the glans penis which it represents, a 
very sensitive epithelium. The prepuce, or fold of skin which covers it, and the 
frenulum which is attached to it inferiorly, are continuous with the labia minora 
(Fig. 778). 
The crura clitoridis diverge from the body posteriorly, and are attached to the 
sides of the pubic.arch. Each is continuous with one of the corpora cavernosa, and 
has a firm fibrous sheath, which is covered by the corresponding ischio-cavernosus 
or erector clitoridis muscle. In structure the crura and body of the clitoris re- 
semble the corpora cavernosa penis, while the glans more closely resembles the 
bulbus vestibul, with which it is continuous through a structure known as the 
pars intermedia. 
In the seal and some other animals, a bone, which represents the os penis of the male, is 
developed in the septum of the clitoris. This bone receives the name os clitoridis. 
Arteries and Nerves of the Clitoris.—Each crus receives a branch (arteria profunda clito- 
ridis) from the internal pudic artery, while the glans is supplied by branches of the dorsal arteries 
of the clitoris (arterize dorsalis clitoridis). The nerve supply of the clitoris is derived partly from 
the hypogastric sympathetic plexus and partly from the dorsal nerves of the clitoris. 
Bulbus Vestibuli.—The bulbus vestibuli is a mass of erectile tissue, in the 
female, which corresponds developmentally to the corpus spongiosum urethra of 
the male. In the female the fusion of the two halves of this structure is not 
nearly so complete as in the male, for the vagina and urethra separate the bulbus 
vestibuli into two lateral portions which are only slightly connected in front by a 
narrow median part called the pars intermedia. Hach lateral portion of the bulb is 
thick and massive posteriorly, and more pointed in front where it joins the pars 
intermedia. It rests against the side wall of the vagina, and upon the superficial 
aspect of the triangular ligament. Superficially it is covered by the bulbo- 
cavernosus muscle. The pars intermedia hes above the urethra, and becomes con- 
tinuous with the tissue of the glans clitoridis. It represents a part of the corpus 
spongiosum urethree of the male. 
The bulbus vestibul is for the most part composed of minute convoluted blood- 
vessels, held together by a very small amount of connective tissue. These vessels 
frequently anastomose with one another, and those of each lateral half are con- 
tinuous with the vessels of the pars intermedia and of the glans clitoridis. 
The blood supply of the bulb is derived on each side from a branch (arteria bulbi 
vestibuli) of the internal pudic. 
THE GLANDS OF BARTHOLIN. 
The glands of Bartholin (glandul vestibulares majores) are placed one on each 
side of the lower part of the vagina, and represent Cowper's glands in the male. 
They are often overlapped by the posterior ends of the bulbus vestibuli, and are 
covered by the bulbo-cavernosus muscle. Each is about the size and shape of : 
small bean, and possesses a long slender duct which opens into the urogenital cleft 
in the angle between the attached border of the labium minus and the vaginal 
opening. 
DEVELOPMENT OF THE UROGENITAL ORGANS. 
In tracing the developmental history of the urogenital system we may begin with an 
embryo of fifteen days old. About this time a duct, which runs in the longitudinal 
direction, and occupies a position on the outer side of the paraxial mesoblast, begins to 
develop on each side of the body. With the exception of the anterior portion of the 
cloaca and the proximal part of the allantois, this duct, which has received the name of 
Wolffian duct, is the earliest formed structure from which, or in connexion with which, 
any portion of the adult urogenital system is derived. 
