The essentially motor character of detumescence is well shown by the extreme forms of erotic intoxication which sometimes appear as the result of sexual excitement. Féré, who has especially called attention to the various manifestations of this condition, presents an instructive case of a man of neurotic heredity and antecedents, in whom it occasionally happened that sexual excitement, instead of culminating in the normal orgasm, attained its climax in a fit of uncontrollable muscular excitement. He would then sing, dance, gesticulate, roughly treat his partner, break the objects around him, and finally sink down exhausted and stupefied. (Féré, _L'Instinct Sexuel_, Chapter X.) In such a case a diffused and general detumescence has taken the place of the normal detumescence which has its main focus in the sexual sphere. The same relationship is shown in a case of impotence accompanied by cramps in the calves and elsewhere, which has been recorded by Brügelmann ("Zur Lehre vom Perversen Sexualismus," _Zeitschrift für Hypnotismus_, 1900, Heft I). These muscular conditions ceased for several days whenever coitus was effected. An instructive analogy to the motor irradiations preceding the moment of sexual detumescence may be found in the somewhat similar motor irradiations which follow the delayed expulsion of a highly distended bladder. These sometimes become very marked in a child or young woman unable to control the motor system absolutely. The legs are crossed, the foot swung, the thighs tightly pressed together, the toes curled. The fingers are flexed in rhythmic succession. The whole body slowly twists as though the seat had become uncomfortable. It is difficult to concentrate the mind; the same remark may be automatically repeated; the eyes search restlessly, and there is a tendency to count surrounding objects or patterns. When the extreme degree of tension is reached it is only by executing a kind of dance that the explosive contraction of the bladder is restrained. The picture of muscular irradiation presented under these circumstances differs but slightly from that of the onset of detumescence. In one case the explosion is sought, in the other case it is dreaded; but in both cases there is a retarded muscular tension,--in the one case involuntary, in the other case voluntary--maintained at a point of acute intensity, and in both cases the muscular irradiations of this tension spread over the whole body. The increased motor irritability of the state of detumescence somewhat resembles the conditions produced by a weak anæsthetic and there is some interest in noting the sexual excitement liable to occur in anæsthesia. I am indebted to Dr. J.F.W. Silk for some remarks on this point:--