sexual acts which are connected with pleasure and excitement become preparatory acts for the new sexual aim, the voiding of the sexual products, the attainment of which under enormous pleasure puts an end to the sexual feeling.  At the same time we had to consider the differentiation of the sexual nature of man and woman, and we found that in order to become a woman a new repression is required which abolishes a piece of infantile masculinity, and prepares the woman for the change of the leading genital zones.  Lastly, we found the object selection, tracing it through infancy to its revival in puberty; we also found indications of sexual inclinations on the part of the child for the parents and foster-parents, which, however, were turned away from these persons to others resembling them by the incest barriers which had been erected in the meantime.  Let us finally add that during the transition period of puberty the somatic and psychic processes of development proceed side by side, but separately, until with the breaking through of an intense psychic love-stimulus for the innervation of the genitals, the normally demanded unification of the erotic function is established.

The Factors Disturbing the Development.—­As we have already shown by different examples, every step on this long road of development may become a point of fixation and every joint in this complicated structure may afford opportunity for a dissociation of the sexual impulse.  It still remains for us to review the various inner and outer factors which disturb the development, and to mention the part of the mechanism affected by the disturbance emanating from them.  The factors which we mention here in a series cannot, of course, all be in themselves of equal validity and we must expect to meet with difficulties in the assigning to the individual factors their due importance.

Constitution and Heredity.—­In the first place, we must mention here the congenital variation of the sexual constitution, upon which the greatest weight probably falls, but the existence of which, as may be easily understood, can be established only through its later manifestations and even then not always with great certainty.  We understand by it a preponderance of one or another of the manifold sources of the sexual excitement, and we believe that such a difference of disposition must always come to expression in the final result, even if it should remain within normal limits.  Of course, we can also imagine certain variations of the original disposition that even without further aid must necessarily lead to the formation of an abnormal sexual life.  One can call these “degenerative” and consider them as an expression of hereditary deterioration.  In this connection I have to report a remarkable fact.  In more than half of the severe cases of hysteria, compulsion neuroses, etc., which I have treated by psychotherapy, I have succeeded in positively demonstrating