Inverted sexuality, the sexual instinct diverted from its normal channel, directed (in the case Of males) to males, forms the topic Of the following discourse. The study will be confined to modern times, and to those nations which regard the phenomenon with religious detestation. This renders the enquiry peculiarly dith cult, and exposes the enquirer, unless he be a professed expert in diseases of the mind and nervous centres, to almost certain misconstruction. Still, there is no valid reason why the task of statement and analysis should not be undertaken. Indeed, one might rather wonder why candid and curious observers of humanity have not attempted to fathom a problem which faces them at every turn in their historical researches and in daily life. Doubtless their neglect is due to natural or acquired repugnance, to feelings of disgust and hatred, derived.