Twenty-five per cent die as a rule under best conditions. Fifty per cent when left to nature. _Treatment of Cephalic Presentation._— Extraction of child or reposition of cord, depending upon the degree of dilatation. If cervix is small, replace and fill cervix with Vorhees bag. When cervix admits hand, either replace or do version and extraction. With head engaged, reposition or version is not possible. Child living:—Rapid delivery with forceps. Child dead:—Craniotomy or leave to nature. Prolapse of one or both hands may take place. If the head is engaged, no interference should be attempted. If not, replacement or version may be done. The soft parts may also complicate the labor process. No time need be spent here on the rarer forms of obstruction due to uterine or ovarian tumors. =Rigidity of the cervix, or os= is not uncommon. This may be due to a dense, almost cartilaginous consistence of that tissue, to premature rupture of the bag of waters, to weak, inefficient contractions in the first stage, or to a steel-spring-like contraction of the muscular fibers of the os. In all cases the first stage of labor is greatly prolonged, but so long as the membranes are intact, the child is in no danger. Two kinds of cases are met with, those in which the pains are violent, and those in which they are weak and shallow. In the first class, as soon as the condition is recognized, a dose of morphine sulphate, ⅙ gr. and scopolamine hydrobromide 1/150 gr. should be given, hypodermically. The rigid ring relaxes under the influence of the narcotic, and labor proceeds rapidly and almost painlessly. Chloroform may be substituted if the morphine and scopolamine are not at hand. If the cervix is effaced and only the rigid ring of the os prevents the completion of the labor, or if the above methods fail, then the patient may be anæsthetized and the rigidity overcome by the fingers. This is an emergency that should not be attempted until all else has failed and some danger arises that makes it necessary to hasten the delivery. (See Minor Operations, p. 211). Where the constriction is due to unusual density of the cervix or to cicatricial tissue, it is sometimes necessary to make incisions under aseptic precautions so that the rigid ring may expand. Weak and inefficient contractions can sometimes be stimulated satisfactorily by the introduction of a Vorhees bag. =Rigidity of the pelvic floor= may be due to inadequate elasticity of the tissues as in old primiparas or in young women who have ridden horseback for many years in the cross-saddle position. The head may come down to the pelvic floor but will not advance further. If the tissues of the vulva do not, or can not yield sufficiently after appropriate time has been allowed, episiotomy may be done. (See Minor Operations, p. 211.) The uterus itself may functionate abnormally.