*The Rôle of the Sexual Substance.*--Aside from the fact that only the discharge of the sexual substance can normally put an end to the sexual excitement, there are other essential facts which bring the sexual tension into relation with the sexual products. In a life of continence the sexual activity is wont to discharge the sexual substance at night during pleasurable dream hallucinations of a sexual act, this discharge coming at changing but not at entirely capricious intervals; and the following interpretation of this process--the nocturnal pollution--can hardly be rejected, viz., that the sexual tension which brings about a substitute for the sexual act by the short hallucinatory road is a function of the accumulated semen in the reservoirs for the sexual products. Experiences with the exhaustibility of the sexual mechanism speak for the same thing. Where there is no stock of semen it is not only impossible to accomplish the sexual act, but there is also a lack of excitability in the erogenous zones, the suitable excitation of which can evoke no pleasure. We thus discover incidentally that a certain amount of sexual tension is itself necessary for the excitability of the erogenous zones. One would thus be forced to the assumption, which if I am not mistaken is quite generally adopted, that the accumulation of sexual substance produces and maintains the sexual tension. The pressure of these products on the walls of their receptacles acts as an excitant on the spinal center, the state of which is then perceived by the higher centers which then produce in consciousness the familiar feeling of tension. If the excitation of erogenous zones increases the sexual tension, it can only be due to the fact that the erogenous zones are connected with these centers by previously formed anatomical connections. They increase there the tone of the excitation, and with sufficient sexual tension they set in motion the sexual act, and with insufficient tension they merely stimulate a production of the sexual substance. The weakness of the theory which one finds adopted, _e.g._, in v. Krafft-Ebing's description of the sexual process, lies in the fact that it has been formed for the sexual activity of the mature man and pays too little heed to three kinds of relations which should also have been elucidated. We refer to the relations as found in the child, in the woman, and in the castrated male. In none of the three cases can we speak of an accumulation of sexual products in the same sense as in the man, which naturally renders difficult the general application of this scheme; still it may be admitted without any further ado that ways can be found to justify the subordination of even these cases. Nevertheless one should be cautious about burdening the factor of accumulation of sexual products with actions which it seems incapable of supporting.