The sexual appetite of woman manifests itself at first in vague desires, in a want of love, and does not as a rule develop locally till after coitus. It often follows that in ontogenetic evolution the sexual appetite of women increases at a more advanced age (between thirty and forty). At this age women often become enamored with young boys, whom they seduce easily. Widows are especially disposed to form unions with men younger than themselves; these unions are rarely happy, for the woman who is older than her husband easily becomes jealous, and the husband soon becomes tired of a woman whose charms have faded. We can therefore affirm that, as a rule, in order to be both normal and lasting, a monogamous union requires that the husband should be from six to twelve years older than his wife, and that the latter should marry as young as possible. In the sexual ontogeny of normal woman, pregnancies, childbirth, the nursing and education of children play an infinitely greater role than the sexual appetite. These important events in woman's life, together with affection for her husband occupy a great part of the cerebral activity of every woman, and are at the same time the conditions for her true happiness. We should expect the sexual appetite in woman to diminish or cease at the menopause; but this is not usually the case, and elderly women are sometimes tormented by the sexual appetite, which is all the more painful because men are not attracted by them. Such hyperæsthesia cannot, however, be considered as normal; most often the sexual appetite diminishes with age and is replaced, as in man, by the tranquil love of old age, of which we have spoken.