Pity and a scientific interest induced me to invite the writer of the preceding lines to come to see me. Early in February Mr. D. came. He was distinguished, pleasing, and masculine in appearance. Examination of the case showed it to be one of masochism. He distinctly remembered that, when he once saw fellow-pupils whipped by the teacher, it gave him a feeling of lustful pleasure. He cannot remember that he was ever whipped by a teacher. His masochism had been an _absolutely primary manifestation_, and incomprehensible to him. Only gradually and _faute de mieux_ had he come to practice onanism, during which ideas of flagellation, in which he played the passive _rôle_, filled his mind. He had never had desire to be whipped by the teacher; he always wished to be flogged by fellow-pupils and well-grown young persons. Since maturity he had never been able to induce himself to satisfy his masochistic inclinations. In intercourse with puellis he had repeatedly had the thought to have himself whipped by them; but since this was not accompanied by sensual feeling, it was not carried out. The patient declares that his inclinations toward persons of his own sex are purely masochistic. In other respects he finds nothing interesting in men. Until his eighteenth year the patient had also sadistic tendencies. He was enthusiastic about the position of the pedagogue and wanted to be a teacher in order to be able to flog boys. _This ideal sadism later disappeared entirely._ The patient complains that he feels alone in the world, like a pariah, and that he is different from other men. But his libido toward women had much diminished, possibly as a result of his masturbation. He had no erection at the sight of feminine charms, but the sight of a riding-whip or a cane excited him powerfully sexually. When he attempted coitus, no masochistic ideas occurred. Such ideas arose, however, whenever he saw attractive young men. He believed that if he were freed from his ideas of flagellation, he would be helped; for his sensuality would then direct itself in a normal path. The patient has neuropathic eyes, but is free from all degenerative signs. In the direction of hereditary taint, it is noteworthy that his maternal grandfather was peculiar, and shot himself while in a psychopathic condition. The patient feels well, save for slight neurasthenic troubles. Patellar reflex increased. The genitals are perfectly normal. His dreams with pollutions are exclusively about flagellation by young persons, particularly soldiers with tight trousers.