_Aristotle_ wrote at some length on the functions of the female genital organs. In the writings of _Aretæus_ and _Galen_ on the diseases of women we find striking observations, as for instance, in _Galen’s De Locis Affectis_,[4] which contains a “Statement of the Similarity and Dissimilarity of Man and Woman.” Another notable work is that of _Albertus Magnus_, entitled _De Secretis Mulierum_.[5] The numerous works on the diseases of women published in the sixteenth century consisted for the most part of a repetition of the observations of ancient writers. The gynecological treatises of the eighteenth century, however, bore witness to an increased knowledge of the anatomy of the female reproductive organs, and were illumined by _Haller’s_ researches on the functions of these organs. The subject with which we are especially concerned is discussed in a work by _Boireau-Laffecteur_, _Essai sur les Maladies Physiques et Morales des femmes_,[6] Paris, 1793; and also in _Marie-Clement’s Considerations Physiologiques sur les Diverses Epoques de la Vie des Femmes_,[7] Paris, 1803. the same connection we must mention _von Humboldt’s_ treatise, _Ueber den Geschlechtsunterschied und dessen Einfluss auf die organische Natur_.[8] The first comprehensive work in which an exhaustive inquiry was made into the functional disorders of the female genital organs and the relation of these disorders to the female organism as a whole and to the physical and mental peculiarities of woman was _Busch’s: Das Geschlechtsleben des Weibes_,[9] Leipzig, 1839. In the second half of the nineteenth century a very large number of monographs were published, investigating and describing the reflex disturbances produced alike in the individual organs and in the nervous system as a whole by changes in the uterus and its annexa. Many of these works will be mentioned more particularly in the course of this treatise. The sexual life, based upon the purpose, so important to every creature, of the propagation of the species, possesses in the female sex a vital significance enormously greater than sexual activity possesses in the male. From the very beginning of sexuality, when the idea of a bisexual differentiation dawns for the first time in the brain of the little girl, down to the sexual death of the withered matron, who laments the loss of her sexual potency, physical and mental activity, work and thought, function and sensation, arise for the most part, wittingly or unwittingly, from that germinal energy which is the manifestation of the unalterable law that the existing organism endeavors to reproduce its kind.