[Illustration: _a a_ Half the bladder on each side turned over the spine of the os ilium. _b_ Anterior extremity of the vertical incision by which the bladder was opened. _c_ One turn of the rectum, which was seen at the posterior end of the same incision. _W. Hunter._] Retroversion of the uterus appears to have been known to the ancients, as we find it alluded to by Hippocrates (_De Nat. Mulieb._ sect. 5.) and Philumenus (_Histoire de la Chirurg._ par Dujardin and Peyrhille, t. ii. p. 280.) Oetius, who has quoted the works of the celebrated Aspasia, describes this displacement of the uterus very exactly, and gives rules for introducing two fingers into the rectum, in order to remedy it. Rod. a Castro, who wrote in the sixteenth century, in his work on the diseases of women, quotes what Hippocrates had written on the subject of this displacement; and it is astonishing that no farther notice was taken of it until the eighteenth century, when it excited considerable attention among accoucheurs. (_Martin le Jeune_, p. 137.) Gregoire appears to have been the first who gave a good description of it; his pupil, Mr. W. Wall, on his return to England, met with what he considered to be a case of this displacement, and not being able to restore the uterus to its natural position, requested the advice of Dr. W. Hunter. On passing his finger between the os uteri and symphysis pubis, and thus removing, in some degree, the pressure upon the neck of the bladder, a considerable quantity of urine was discharged, but he was unable to return the uterus to its natural situation, and the patient gradually sunk. The bladder was found immensely distended; the lower part of it, "which is united with the vagina and cervix uteri, and into which the ureters are inserted, was raised up as high as the brim of the pelvis by a large round tumour, (viz. the uterus,) which entirely filled up the whole cavity of the pelvis. The os uteri made the summit of the tumour upon which the bladder rested, and the fundus uteri was turned down towards the os coccygis and anus." (_Medical Obs. and Inquiries_, vol. iv. 404.) _Causes._ This displacement may also occur in the unimpregnated state, either from the fundus being pushed into that position by some morbid growth, or where this effect has been produced by the violent pressure of the abdominal muscles in lifting heavy weights, under circumstances where the uterus has been larger and heavier than usual;[51] but it is in the early months of pregnancy that it is most likely to happen, because now the fundus is both larger and heavier than before, and, therefore, more liable to be affected by the pressure of the intestines and abdominal muscles, and has not yet attained a sufficient size to prevent its undergoing this displacement in the pelvis: this period is about the third or fourth month, often before it, but never after it. (Burns's _Anatomy of the Gravid Uterus_, p. 17.)