Sexual inversion, in persons of the third main species, has reached its final development. Descending, if we follow Krafft-Ebing's categories, from acquired to innate inversion, dividing the latter into psychopathic hermaphrodites and Urnings, subdividing Urnings into those who retain their masculine habit and those who develop a habit analogous to that of females, we come in this last class to the most striking phenomenon of inverted sex. Here the soul which is doomed to love a man, and is nevertheless imprisoned in a male body, strives to convert that body to feminine uses so entirely that the marks of sex, except in the determined organs of sex, shall be obliterated. And sometimes it appears that the singular operation of nature, with which we are occupied in this Essay, goes even further. The inverted bias given to the sexual appetite, as part of the spiritual nature of the man, can never quite transmute male organs into female organs of procreation. But it modifies the bony structure of the body, the form of the face, the fleshly and muscular integuments to such an obvious extent that Krafft-Ebing thinks himself justified in placing a separate class of androgynous beings (with their gynandrous correspondents) at the end of the extraordinary process. At this point it will be well to present a scheme of his analysis under the form of a table. { Persistent. { Acquired { { { Episodical. { Sexual Inversion { { Psychopathic Hemaphrodites. { { { { { Male Habitus { { { (Mannlinge). { Congenital { Urnings { { { Female Habitus { { (Weiblinge). { { Androgyni. What is the rational explanation of the facts presented to us by the analysis which I have formulated in this table cannot as yet be thoroughly determined. We do not know enough about the law of sex in human beings to advance a theory. Krafft-Ebing and writers of his school are at present inclined to refer them all to diseases of the nervous centres, inherited, congenital, excited by early habits of self-abuse. The inadequacy of this method I have already attempted to set forth; and I have also called attention to the fact that it does not sufficiently account for phenomena known to us through history and through every-day experience.