C. HYPERÆSTHESIA (ABNORMALLY INCREASED SEXUAL DESIRE). Pathology has no easy task, in the single case, when it has to decide whether the impulse to sexual satisfaction has reached a pathological degree. Emminghaus (“Psychopathologie,” p. 225) declares that the immediate re-awakening of desire after satisfaction, with its occupation of the entire attention, and no less the excitation of libido by the sight of persons and things which in themselves should have but an indifferent sexual effect, are decidedly abnormal. In general, sexual instinct and its corresponding needs are in proportion to physical strength and age. Sexual desire rapidly increases after puberty, until it reaches a marked degree; is strongest from the twentieth to the fortieth year, and then slowly decreases. Married life seems to preserve and control the instinct. Sexual intercourse with many persons increases the desire. Since woman has less sexual need than man, a predominating sexual desire in her arouses a suspicion of its pathological significance; and the more, when this finds expression in desire for adornment, coquetry, or male society, which, passing beyond the limits set by good breeding and manners, becomes quite noticeable. The constitution, in both sexes, is of the greatest significance. An abnormally strong sexual instinct is frequently accompanied by a neuropathic constitution; and such individuals pass a great part of their lives heavily burdened with the weight of this constitutional anomaly of their sexual life. The power of the sexual impulse in such cases may at times rise to the importance of an organic necessity, and really endanger the freedom of the will. The want of satisfaction of this impulsive desire may, under such conditions, induce a condition allied to actual rutting, or a psychical condition, accompanied by emotions of fear, in which the individual gives up to the impulse, and responsibility becomes doubtful. If the individual does not give up to his powerful impulse, he is in danger, by reason of his enforced abstinence, of ruining his nervous system by inducing a neurasthenia, or seriously increasing such a condition if it be already present. In normally constituted individuals, too, the sexual instinct is an inconstant quantity. Aside from the temporary indifference following satisfaction, and the diminution of sexual desire in long-continued continence after a certain reactionary stage of sexual desire is overcome, the manner of life has a great influence. Those living in large cities, who are constantly reminded of sexual things and incited to sexual enjoyment, certainly have more sexual desire than those living in the country. A dissipated, luxurious, sedentary manner of life, preponderance of animal food, and the consumption of spirits, spices, etc., have a stimulating influence on the sexual life. In woman the sexual inclination is post-menstrually increased. At this time, in