In the new-born female infant, the hymen has the appearance of a tubular stopper closing the lower end of the vagina; according to _Dohrn_ it exhibits as a rule one of three typical forms: _Hymen annularis_, _denticulatus_, _et linguiformis_; the _annular_, the _denticulate_, and the _linguiform_ (or _linguliform_) _hymen_. The transverse ridges on the inner surface of the hymen, prolongations of the rugose columns of the vagina, are strongly developed. During the girl’s further growth, in association with the enlargement of the vagina, the hymen undergoes important changes in form and structure. Its border becomes thinner and more tense; and in the virgin at the time of the menarche, the annular hymen is the fundamental type, subject, however, to extensive variations. In most cases, at any rate, the aperture in the hymen is more or less centrally situated; very commonly, however, this opening is crescentic, when we have a semilunar hymen, the height of the border posteriorly being much greater than anteriorly. The consistency of the hymen, its extensibility, and its thickness, are as variable as its shape. [Illustration: FIG. 20.—Semilunar Hymen. ] [Illustration: FIG. 21.—Annular Hymen with congenital Symmetrical Indentations. ] [Illustration: FIG. 22.—Fimbriate Hymen. ] [Illustration: FIG. 23.—Deflorated Fimbriate Hymen. ] In the normal position of the reproductive organs the hymen has very rarely the appearance of a tense membrane; as a rule it is folded up, and becomes plainly manifest only when the genital organs are stretched. The margin of the hymeneal aperture, as a close examination shows, is sometimes sharp and regular, sometimes lobulated, with small congenital notches. These congenital notches are to be distinguished from the lacerations resulting from defloration by the fact that the former have a smooth border, which is of the same consistency as the general substance of the hymen. In some instances the border of the aperture in the hymen is beset with small, fine villi (villous hymen). The common varieties of the hymen are thus classified by _Maschka_: 1. The _annular hymen_, in which the membrane when stretched is seen to have a rounded aperture, which may be central or eccentric; very often, indeed, the aperture is more toward the upper half of the hymen, in which case it is not always circular, but frequently rather ovoid in shape. 2. The _semilunar_ or _crescentic hymen_, in which the aperture is eccentrically placed in the upper half of the membrane, in such a manner that the hymen exhibits a wide surface below the aperture, which surface narrows at either side as it passes upwards until it disappears, the two sides failing to reunite above the aperture.