Falling of the vagina is principally due to a widening of the vaginal canal, a relaxation of its walls, and injuries or lacerations of the pelvic floor. Lacerations of the perineum generally occur during confinement, in which the vagina tears through the vaginal orifice backwards towards, or into, the rectum. This so weakens the pelvic floor that it becomes inadequate to support the pelvic organs and tissues, and this predisposes to all the varieties of _prolapsus_ that have been enumerated above. It is during the period of gestation that the vagina grows considerably longer and wider. In the latter months of pregnancy the womb ascends and its body inclines greatly forwards, which naturally tilts the cervix high up in the pelvis, and also draws that portion of the vagina to which the cervix is attached with it, but notwithstanding this upward dragging of the vagina, the lower portion of the vaginal canal has so augmented its proportions that it often protrudes between the lips of the vulva during the last period of gestation. The normal relation of the vagina to the neighboring organs is more or less disturbed, that is, its attachment to the bladder and rectum is stretched and loosened, so that under the most favorable circumstances the mucous membrane of the lower portion of the vagina falls out of the vulva or prolapses, of course in the majority of cases only in such a degree that it neither inconveniences nor is it noticeable by the pregnant woman. Immediately after confinement, in a healthy state of affairs, nature should rectify these abnormal proportions, that were only designed by her to serve a temporary purpose, namely, to accommodate the child and provide for its safe passage into the world. Medical writers have invented a special term to designate this process of regeneration, namely, _involution_. This means to infold or grow less so as to assume the former natural proportions of organs. Unfortunately, nature is often contravened in her wholesome regenerative purpose, by adventitious circumstances that completely frustrate her intentions, and the reparative process being thus balked, the organs and tissues remain in their abnormal proportions, which constitutes now a disease, and this uncompleted effort to repair is termed _subinvolution_. It takes at least from six weeks to three months after delivery for the reparative process or involution of the organs and tissues to be completed. And women cannot exercise too much care after confinement to avoid any possible check to the regenerative process. If the involution has been arrested, the vagina retains its large, flabby proportions, so that its relaxed walls naturally protrude or prolapse, and that entails all the other consequences.