Following the demonstration by Blair Bell and by Hofbauer that extracts of the posterior portion of the hypophysis stimulate uterine contractions in women, the use of such preparations soon became popularized and now has reached such proportions as to constitute a distinct danger. Clinical experience teaches that the hypodermic injection of from 0.5 to 1 c.c. of an efficient pituitary extract into a woman in labor is followed within two or three minutes by a marked increase in the frequency and force of the uterine contractions, as well as by a slight rise in blood pressure. Fortunately, in certain respects, the maximum effect is of short duration, beginning to decline in ten or fifteen minutes, and disappearing completely within thirty minutes. Ordinarily, such a dose merely leads to an increase in the force of the individual contractions, but occasionally the uterus promptly passes into a tetanic condition, and no longer