The following case, published by Arndt (_Vierteljahrsschr. f. ger. Medicin_, N. F. xvii, H. 1), belongs here:— Case 31. A., medical student at Greifswald, accusatus quod iterum iterumque puellis honestis parentibus natis in publico genitalia sua e bracis dependentia plane nudata quæ antia summo amiculo (overcoat) tecta erant, ostenderat. Nonnunquam puellas fugientes secutus easque ad se attractas urina oblivit. Hæc luce clara facta sunt; nunquam aliquid hæc faciens locutus est. A. is twenty-three years old, powerfully built, neat in dress, and decent in manners. Indication of cranium progeneum; chronic pneumonia of the apex of the right lung; emphysema. Pulse, 60; in excitement, not more than 70 to 80. Genitals normal. Complaints of occasional disturbances of digestion and hardness of the abdomen, vertigo; excessive excitement of the sexual desires, which early led to onanism. The sexual desire has never been directed toward a natural method of satisfaction. Complaints of occasional attacks of depression, or thoughts of deprecation of self, and of perverse impulses, for which he could find no motive; such as laughing at serious things, throwing his money in the water, and running about in the pouring rain. The father of the culprit is of a nervous temperament; his mother is subject to nervous headache. A brother suffered with epileptic convulsions. From his youth the culprit presented a nervous temperament, was inclined to convulsions and attacks of syncope, and when he was severely scolded would fall into a state of momentary stiffness. In 1869 he studied medicine in Berlin. In 1870 he went to the war as a hospital-assistant. His letters at this time betray a peculiar torpidity and weakness. On his return home, in 1871, his emotional irritability was noticed by those about him. Thereafter frequent complaints of bodily ailments; unpleasantness resulting from a love affair. In November, 1871, he pursued his studies diligently in Greifswald. He was considered very gentlemanly. In confinement he is quiet, calm, and sometimes self-absorbed. His acts he attributes to painful sexual excitement, which of late had become excessive. He declared that he had been fully conscious of his perverse acts, and had afterward been ashamed of them. He had not experienced actual sexual satisfaction in their commission. He obtained no correct insight into his position. He considered himself a kind of martyr,—fallen a victim to an evil power. Presumption of irresponsibility, as a result of absence of free will. The impulse to defile occurs also, paradoxically, in the aged, when there is a re-appearance of sexual instinct, which, under such circumstances, is so often expressed in perverse acts. Thus Tarnowsky reports (p. 76) the following case:—