Kobelt, in his celebrated work on the human organs of sexual pleasure (Freiburg, 1884, p. 55 _et seq._), gave a similar description of copulation. In the majority of descriptions of coitus but little attention is usually paid to the demeanour of the woman. Magendie long ago drew attention to the fact that there was much obscurity about this matter, and insisted that, in comparison with the male, the female exhibited extremely marked differences, in respect to her active participation in copulation and to the intensity of her voluptuous sensations. “Very many women,” says this distinguished physiologist, “experience a sexual orgasm accompanied by very intense voluptuous sensations; others, on the contrary, appear entirely devoid of sensation; and some, again, have only a disagreeable and painful sensation. Many women excrete, at this moment of most intense sexual pleasure, a large quantity of mucus, but the majority do not exhibit this phenomenon. In reference to all these phenomena, =there are perhaps no two women who are precisely similar=.” The demeanour of the woman _in coitu_ has been especially studied by gynæcologists, such as Busch, Theopold, and recently Otto Adler. Little known are the observations of Dr. Theopold, based upon his own experience, and published in 1873. He energetically denies the view that the woman is always passive in coitus, and also that the female reproductive organs are inactive during intercourse. During erotic excitement in woman the heart beats more frequently, the arteries of the labia pulsate powerfully, the genital organs are turgid and are hotter to the touch. As the most intense libido approaches, the uterus undergoes erection; its base touches the anterior abdominal wall; the Fallopian tubes can be distinctly felt through the abdominal wall, when these are thin, as hard, curved strings. The vagina, especially the upper part of the passage, undergoes rhythmical contraction and dilation, and complete gratification terminates the act. As long as the muscle guarding the vaginal outlet (constrictor cunni--bulbo-cavernosus muscle) is intact, the woman is able, by tightly grasping the root of the penis, to expedite the ejaculation of semen, or to increase the stimulation of the male until ejaculation occurs.