savage tribes, elongation of the labia minora and the clitoris is artificially undertaken from the earliest years of girlhood, this elongation being regarded as a beauty. The parts of the external reproductive organs of the female concerned in sexual sensation, first described as such by _Kobelt_, are already fully developed at the time of the menarche. Of these parts a small portion only, the glans clitoridis, is visible externally, surrounded by the præputium clitoridis, a prolongation of the labia minora, which passes round the front of the clitoris, and sends from each side a fine process behind the glans to become attached to its under surface, forming the frænum of the clitoris. The erectile apparatus of the external genitals is formed by the corpora cavernosa clitoridis. As two delicately constructed trabecular masses of erectile tissue, the crura of the clitoris, these are attached on either side to the inferior or descending rami of the pubic bones; at first passing upwards parallel to the bones, they subsequently curve downward as they converge and unite to form the body of the clitoris; these masses of erectile tissue embrace the sides and the front of the lower extremity of the vagina. This erectile apparatus, when the supply of arterial blood is greatly accelerated and at the same time the outflow of venous blood is diminished, becomes distended with blood, enlarged and stiffened; the process of erection plays an important part, as we shall explain more fully later, in the production of sexual excitement and sexual pleasure during the act of copulation. In the virgin and in the earlier phases of the sexual life, the hymen is so characteristic an organ that its more minute description would seem desirable. The hymen, a fold of mucous membrane, springing from the periphery of the vaginal orifice, separates as a perforated diaphragm the vagina from the vulva. Between the two epithelial layers of which, as a fold of mucous membrane, the hymen consists, is a supporting layer of connective tissue of variable strength; in other respects the mucous membrane of the hymen has the same structure as the mucous membrane of the vagina. On its inner surface the rugæ and folds of the vaginal mucous membrane are prolonged. The shape of the hymen is very variable; most commonly its aperture is more or less central, so that the hymen has a ringed or semilunar shape. [Illustration: FIG. 18.—Annular Hymen. ] [Illustration: FIG. 19.—Annular Hymen. ]