In descent of the first degree the location of the uterus is either changed to a lower level, the position remaining normal, or, as is more common, the cervix having moved nearer to the symphysis and the organ turns back into retroversion. In a given case suppose the vaginal walls from some cause to have become relaxed and to have settled {156} to a lower level in the pelvis. As an associated fact the uterus to which these walls are attached must then also occupy a place correspondingly nearer to the vulva--_i.e._ the location of the uterus has changed, so that space enough intervenes between it and the hollow of the sacrum for the former to turn back into the position of retroversion or retroflexion. If, on the contrary, the descending uterus still maintains its normal anteversion and anteflexion, it must occupy space which belongs to the bladder. The vesical irritation consequent upon this mal-location has generally been ascribed to the anteversion and anteflexion, which are therefore oftentimes wrongly pronounced pathological. The prompt relief which follows permanent replacement of the organ in the normal location, even though in so doing its anteposition be exaggerated, proves that the symptoms depend upon the mal-location, not upon the anteposition. The importance of a clear distinction, therefore, between location and position becomes apparent. Vesical irritation, moreover, is sometimes caused by the dragging of the uterus upon the neck of the bladder. This traction occurs not only in ascent, but also when the organ descends below a certain level. [Illustration: FIG. 4. Showing Extreme Descent of the Uterus and of the Pelvic Floor, and the Hernial Character of the Lesion.] In the foregoing paragraphs traction due to the falling pelvic floor has been discussed as a cause of descent. The impairment of the uterine supports may, however, be such that instead of falling and dragging the uterus after them, they simply permit it to descend along the vaginal canal by the force of its own weight, and to carry with it the reduplicated vaginal walls. This influence is generally enforced by the increased weight of the diseased organ. The vagina more readily becomes a track for the descending uterus when from any cause the normal forward direction of the vaginal canal changes toward the vertical: this change may occur either as the result of a forward displacement of its upper extremity, involving anteposition of the cervix, or of a retro-displacement of its {157} lower extremity in consequence of rupture or subinvolution of the perineum. (See Fig. 3.) Descent in the track of the vagina is obviously combined with some degree of retroversion, because the axes of the uterus and vagina then correspond.