Cases have now and then been met with where the retroversion of the uterus has continued to an advanced period of pregnancy without producing serious injury to the patient: Dr. Merriman has even recorded some, where the uterus has continued in this state up to the full term. Some of these had been actually published as cases of ventral pregnancy; but for their history he has shown that they evidently were cases of retroversion: the patient had been subject to occasional suppressions of urine and difficulty in passing fæces; these symptoms had gradually diminished as pregnancy advanced; the os uteri could not be felt, or, if it were capable of being reached, was found high up behind the pubes, the head of the child forming a large hard tumour between the rectum and vagina. The condition of the vagina afforded strong evidences of the nature of the complaint: on introducing the finger in the usual direction, it was stopped, as if in a cul-de-sac: but on passing it forwards, the vagina was found pulled up behind the symphysis pubis. In some of these cases the uterine contractions gradually restored the fundus to its natural position: the os uteri descended from behind the symphysis, and the child was born after long protracted suffering; in others, which have been mistaken for ventral pregnancy, the fundus has inflamed and ulcerated, and the child has been gradually discharged by piecemeal. CHAPTER VII. DURATION OF PREGNANCY. There are few questions of great importance and interest respecting a subject under our daily observation, about which such uncertainty and so much diversity of opinion exists, as the duration of human pregnancy; and yet, as is the case with the diagnosis of pregnancy, upon a correct decision frequently depend happiness, character, legitimacy, and fortune. In like manner it frequently happens, that the data upon which we have to found our opinion are exceedingly doubtful and obscure; and to increase the difficulties of the investigation still farther, we have not uncommonly to contend with wilful deception and determined concealment. The duration of pregnancy must ever remain a question of considerable uncertainty so long as the data and modes of calculation vary so exceedingly. "Some persons date from the time at which the monthly period intermits; others begin to calculate from a fortnight after the intermission; some reckon from the day on which the succeeding appearance ought to have become manifest; some are inclined to include in their calculation the entire last period of being regular; and others only date from the day at which they were first sensible of the motions of the infant."[58]