Many other causes of malposition have been enumerated by authors, which evidently exist only in theory and not in reality: thus, shortness of the umbilical cord, or its being twisted round the child, insertion of the placenta to one side of the uterus, faulty form or inclination of the pelvis, obliquity of the uterus, as above-mentioned, violent exertions or concussions of the body, plurality of children; of all these, we do not believe that there is one which can exert the slightest influence in determining the position of the child. There is no doubt that several of them will render labour difficult or even dangerous, more especially deformed pelvis; but we constantly meet with it under every degree and variety without at all altering the child's position. Indeed, if malformation of the pelvis were to be a cause of malposition of the child during labour, what difficulties would it not add to the process of delivery under such circumstances? And yet we find, with very rare exceptions, that in every case requiring artificial assistance on account of contracted pelvis, the head is resting upon the brim which is too narrow to allow it to pass. We may also mention another circumstance which has occasionally seemed to produce a faulty position of the child. It sometimes happens that the hand, which is frequently felt lying by the side of the face at the beginning of labour, instead of slipping up out of reach as the head descends, which is usually the case, advances more and more, until it not only prevents the head from engaging farther into the pelvis, but pushes it out, so that the head slips up to one side, and lodges in the cavitas iliaca, allowing the shoulder with the rest of the arm to descend. Where, however, the pelvis is large or the head small, the arm will not always force it to one side, but the two will come down together and be born in this position. (See case in our _Midwifery Reports, Med. Gaz._ April 19, 1834.) Sometimes the two hands present (_La Motte_, book iii. ch. 26.,) or a hand and foot: this, however, does not long continue so, for when the membranes have ruptured, the liquor amnii flowed away, and the uterus contracted upon the child, one shoulder and arm descend before the rest, and remain in this position. The complication of two arms presenting with the head we disbelieve entirely, except where it has been made during some awkward and ignorant attempts at delivery.