5i MAMMALIA. 



also in its middle, but rarely posteriorly, there is often found, as in 

 the Horse, the Ruminantia, Carnivora, and Apes, a fold or septum, 

 in one case strong, in another merely rudimentary, which corresponds 

 to the hymen of the human female, but is never so peculiarly devel- 

 oped as in the latter. 



The Clitoris appears to be generally present, and occurs also in 

 the Monotremata and Cetacea. It is usually situated far forward, 

 consists of cellular tissue, and is provided with a glans, and pre- 

 puce. It is very much developed in the Rodentia, Carnivora, and 

 Apes, and in them contains not unfrequently a cartilage or bone 

 analogous to that of the penis. Thus there is found a small bone in 

 the domestic Cat, which is larger in other species of the Feline 

 race, and in the Otter, Bear, Marmot, &c., but is apparently fre- 

 quently wanting in the Apes. A clitoris, on the contrary, of unusual 

 size occurs in the Spider-monkeys (Ateles), being from two to three 

 inches long, and provided with a glans and conspicuous prepuce, 

 upon the under surface of which a groove runs from the orifice of 

 the bladder, along which the urine flows. In the Marsupiata, the 

 clitoris is split like the glans of the male, and there project from it 

 two folds forming a groove for the passage of the urine, or, as in 

 the Lemming, the Makis, and Loris, the clitoris is actually perfo- 

 rated, and thus attains the highest grade of analogy with the male 

 penis. The spongy bodies and arteriae helicinse are frequently 

 wanting, and the body is filled with fat, so that even in the Spider- 

 monkeys, it is probably incapable of erection. The preputial glands 

 of the clitoris are occasionally very much developed ; and in some 

 Carnivora, Marsupiata, Ruminantia, and Rodentia, we also find at 

 the base of the clitoris more or less distinctly developed Cowper's 

 glands, which have been lately proved to exist in the human female. 

 The nymphae or internal labia are wanting ; the external labia are 

 but slightly developed, and consist only of a pair of hairless pro- 

 jections, which bound a mostly rounded vaginal orifice ; the mons 

 veneris is wanting. In some Mammalia, namely, the Horse and 

 Ruminantia, we find upon either side of that of the urethra the two 

 orifices of what are called the vaginal canals, which run between 

 the muscular and mucous membrane to the broad ligaments of the 

 uterus, but are sometimes entirely closed ; they may probably be re- 

 garded as the remains bf the excretory ducts of the Wolffian bodies 

 or false kidneys in the foetus, and thus as a kind of persistent arrest 

 of formation. 



The Mammary glands, which occur in all the Mammalia, are to 



