Female Organs.--The _ovaries_, _uterus_, or _womb_, _Fallopian tubes_, and _vagina_ have already been described in part. The external organs of the female are included in the term _vulva_ or _pudenda_. The most superficial parts are the _labia_, two thick folds of integument. Just within these are two thinner folds, the _labia minora_ or _nymphae_. These, together with the _clitoris_, situated just above, are extremely sensitive organs, being the chief seat of sexual sense in the female. At the lower part is the opening to the vagina, which in the virgin is usually partially guarded by a thin membrane, the _hymen_. This is not always a reliable test of virginity, however, as commonly regarded, since it may be destroyed by disease or accident, and may exist even after the occurrence of pregnancy. The vagina extends from the vulva to the lower end of the uterus, which it incloses, passing between the bladder and the rectum. The lower extremity of the uterus presents a small opening which leads into its interior. Upon either side, at its upper and larger end, is a minute opening, the mouth of the Fallopian tube. The latter organs extend from the uterus outward nearly to the ovaries, toward which they present a number of small filaments, one of which is in contact with each ovary. These filaments, together with the interior of the tubes, are covered with a peculiar kind of cells, upon which are minute cilia, or hairs, in constant motion. Very curiously, they all move in the same direction, toward the cavity of the uterus. When an ovum escapes from the ovary in connection with menstruation, it is by these delicate hairs propelled along a filament of tissue to the Fallopian tube, and thence by the same means is conveyed to the uterus. It may come in contact with the zoosperms at any point between the ovary and the lower orifice of the uterus, and thus undergo fecundation. Puberty.--For a certain period after birth, the sexual organs remain in a partially developed condition. This period varies in duration with different animals; in some cases being very brief, in others, comprising several years. Upon the attainment of a certain age, the individual becomes sexually perfect, and is then capable of the generative act. This period is called puberty. In man, puberty commonly occurs between the ages of ten and fifteen years, varying considerably in different climates. In this country, and in other countries of about the same latitude, puberty usually occurs at the age of fourteen or fourteen and one-half years in females, and a few months later in males. In cooler climates, as in Norway and Siberia, the change is delayed to the age of eighteen or nineteen years. In tropical climates it is hastened, occurring as early as nine or ten years. In warm climates it is no uncommon thing for a girl to be a mother at twelve; and it is stated that one of the wives of Mahomet was a mother at ten.