During the menacme, in consequence of the act of reproduction, the uterus undergoes important changes in form. In a nulliparous married woman, the uterus differs little from that of a virgin; the cavity is somewhat more extensive, the convexity of the outer surface a little greater, there is some increase in width in the neighborhood of the fundus, the plicæ palmatæ (_arbor vitæ uterinum_) are confined to the cervical canal; further, under the influence of copulation the appearance of the vagina changes, it becomes larger, and its walls become smoother, sometimes quite smooth, from the disappearance of the rugæ of the mucous membrane and especially of those attached to the posterior vaginal column. Much more extensive are the alterations in the uterus of a multipara. According to _Toldt_, “the parts of the cavity representing the cornua, which are pointed on either side as they pass toward the Fallopian tubes, become completely included in the lower undivided portion of the cavity, this change being effected chiefly by means of the increasing outward curvature of the walls, so that the cavity comes to assume an amygdaloid form; the cervical canal is also enlarged, especially the lower part, where also the plicæ palmatæ (_arbor vitæ uterinum_) becomes less distinct; the vaginal portion of the cervix is shortened, the os uteri externum gapes, the lips of the cervix are tumid, nearly equal in length, and usually beset with scarred depressions.” In nulliparae, the vaginal portion of the cervix is, as in a virgin, of a rather tough consistency, smooth on the surface, while the external os is small, like a dimple, or transversely oval; the color of the vaginal portion of the cervix is identical with that of the vaginal mucous membrane in general. Through frequent copulation, however, the form of the vaginal portion of the cervix is so far altered inasmuch as it is more freely supplied with blood, and, therefore, changes slightly, in consistency. In multiparæ, in consequence of lacerations of the cervix, the os uteri externum changes to a wide transverse fissure with tumid margins, justifying the old designation of this orifice as _os tincæ_;, carp’s mouth. A large size of the external and internal os, moderate enlargement of the cavity, rounding of the upper angles adjacent to the uterine orifices of the Fallopian tubes, increased convexity of the walls, and partial or complete effacement of the plicæ palmatæ (_arbor vitæ uterinum_), are the characteristics of the uterus of a multipara (_Chrobak_ and _von Rosthorn_). According to _Hennig_, the vaginal portion of the cervix is longest in women who have undergone defloration, and in nulliparae; widest in prostitutes; narrowest in childless wives; thickest in young widows. This author gives the following measurements of the external os, showing its variations in accordance with age and sexual activity: