A detailed account, fifty-six pages long, of an exceedingly interesting case of dementia praecox in a youth of eighteen. As a reaction against conscious incestuous attraction he became homosexual and developed the psychosis at the age of seventeen. The author traces the sense of inferiority, on Adlerian lines, to the patient's left-handedness and slender build, but that this was not a final analysis is revealed by the patient's delirious remark that he was 'ambidextrous and ambisextrous (bisexual)', shewing that the left-handedness was a symbol for the castration idea behind the homosexuality. The case is well worth reading in the original.