*Explanation of Inversion.*--The nature of inversion is explained neither by the assumption that it is congenital nor that it is acquired. In the first case, we need to be told what there is in it of the congenital, unless we are satisfied with the roughest explanation, namely, that a person brings along a congenital sexual impulse connected with a definite sexual object. In the second case it is a question whether the manifold accidental influences suffice to explain the acquisition unless there is something in the individual to meet them half way. The negation of this last factor is inadmissible according to our former conclusions. *The Relation of Bisexuality.*--Since the time of Frank Lydston, Kiernan, and Chevalier, a new series of ideas has been introduced for the explanation of the possibility of sexual inversion. This contains a new contradiction to the popular belief which assumes that a human being is either a man or a woman. Science shows cases in which the sexual characteristics appear blurred and thus the sexual distinction is made difficult, especially on an anatomical basis. The genitals of such persons unite the male and female characteristics (hermaphroditism). In rare cases both parts of the sexual apparatus are well developed (true hermaphroditism), but usually both are stunted.[9] The importance of these abnormalities lies in the fact that they unexpectedly facilitate the understanding of the normal formation. A certain degree of anatomical hermaphroditism really belongs to the normal. In no normally formed male or female are traces of the apparatus of the other sex lacking; these either continue functionless as rudimentary organs, or they are transformed for the purpose of assuming other functions. The conception which we gather from this long known anatomical fact is the original predisposition to bisexuality, which in the course of development has changed to monosexuality, leaving slight remnants of the stunted sex. It was natural to transfer this conception to the psychic sphere and to conceive the inversion in its aberrations as an expression of psychic hermaphroditism. In order to bring the question to a decision, it was only necessary to have one other circumstance, viz., a regular concurrence of the inversion with the psychic and somatic signs of hermaphroditism. But this second expectation was not realized. The relations between the assumed psychical and the demonstrable anatomical androgyny should never be conceived as being so close. There is frequently found in the inverted a diminution of the sexual impulse (H. Ellis) and a slight anatomical stunting of the organs. This, however, is found frequently but by no means regularly or preponderately. Thus we must recognize that inversion and somatic hermaphroditism are totally independent of each other.