It is these slight but early contractions, which, although they produce little or no effect upon the os uteri, exert a very important influence over the first half of labour; for it is by their action, in great measure, that the form of the uterus is determined, as also the correct position of the child. Hence, therefore, some practitioners lay considerable stress on ascertaining the precise form of the abdomen as a means of determining what sort of labour the patient will have. In a woman pregnant for the first time, and in a state of perfect health, the uterus is of an oval or rather elliptical form at the beginning of labour: when seen in profile, the abdomen presents nearly a uniform degree of convexity. In this state the child lies with its long axis parallel to that of the uterus, that is, with its head or inferior extremity turned towards the brim of the pelvis; and if the fundus has already sunk in the manner above-mentioned, the practitioner may very confidently prognosticate that the head presents, even before making an examination per vaginam. In a perfectly healthy primipara there is scarcely any inclination of the uterus either to one side or forwards, its median line corresponding with that of the abdomen: whereas, in the multipara, the axis of the uterus is seldom straight, inclining more or less to one side, or, from the greater relaxation of the abdominal parietes, being somewhat pendulous. The size of the uterus should also be taken into consideration, especially in first pregnancies; a large uterus shows that either its parietes are gorged with too much blood, or that its cavity is distended with an unusual quantity of liquor amnii, or that the child is very large, or that there are twins. Whatever may be the cause of the distension, it interferes with the regular and effective contractions of the uterus, and tends to make the labour (at least the first part of it) tedious. A moderate sized uterus is much more capable of active exertion, for its fibres not being put so much upon the stretch are enabled to contract better. _True and false pains._ If the patient is already beginning to suffer pains, it is of great importance to ascertain whether they be genuine or spurious; upon the correct diagnosis of which, the favourable or unfavourable course of the labour not unfrequently in great measure depends.