This occurs mostly in consequence of pregnancy, and seems to be caused by the walls remaining hvper-trophied when they ought to undergo the regular involution. The thickened and loose vagina is thrown into folds, and these may project outside the vulva. The prolapse is mostly of the anterior wall, and the urinary bladder is not infrequently dragged downwards with it, forming a Hernia vesicae or Cystocele. Much less common is protrusion of the rectum or Rectocele.