Patient was healthy, strong, of lively sensual temperament. He had manifested powerful sexual instinct abnormally early, and masturbated while yet a small boy. He had coitus the first time at the age of fourteen, he says, with enjoyment and complete power. When fifteen years old, a man sought to seduce him, and performed manustupration on him. X. experienced a feeling of repulsion, and freed himself from the disgusting situation. At maturity he committed excesses in libido, with coitus; in 1880 he became neurasthenic, being afflicted with weakness of erection and ejaculatio præcox. He thus became less and less potent, and no longer experienced pleasure in the sexual act. At this time of sexual decadence, for a long time, he still had what was previously foreign to him, and is still incomprehensible to him,—an inclination for sexual intercourse with immature girls of the age of twelve or thirteen. His libido increased as virility diminished. Gradually he developed inclination for boys of thirteen or fourteen. He was impelled to approach them. Quodsi ei occasio data est ut tangere posset pueros qui ei placuere, penis vehementer se erexit tum maxime quum crura puerorum tangere potuisset. Abhinc feminas non cupivit. Nonnunquam feminas ad coitum coëgit sed erectio debilis, ejaculatio præmatura erat sine ulla voluptate. Now only youths interested him. He dreamed about them and had pollutions. After 1882 he now and then had opportunity concumbere cum juvenibus. This led to powerful sexual excitement, which he satisfied by masturbation. It was only exceptional for him to venture to touch his bed-fellow and indulge in mutual masturbation. He shunned pederasty. For the most part, he was compelled to satisfy his sexual needs by means of solitary masturbation. In the act he called up the vision of pleasing boys. After sexual intercourse with such boys, he always felt strengthened and refreshed, but morally depressed; because there was consciousness of having performed a perverse, indecent, and punishable act. He found it painful that his disgusting impulse was more powerful than his will. X. thinks that his love for his own sex has resulted from great excess in natural sexual intercourse, and bemoans his situation. On the occasion of a consultation, in December, 1889, he asked whether there were any means to bring him back to a normal sexual condition, since he had no real horror feminæ, and would very gladly marry. This intelligent patient, free from degenerative signs, presented no abnormal symptoms except those of sexual and spinal neurasthenia of moderate degree.