vegetation of Peru, beside the streams of Shiraz and the waters of the Ganges, in the cold clear air of Scandinavian winters. It throbs in our huge cities. The pulse of it can be felt in London, Paris, Berlin, Vienna, no less than in Constantinople, Naples, Teheran, and Moscow. It finds a home in Alpine valleys, Albanian ravines, Californian canyons, and gorges of Caucasian mountains. It once sat, clothed in Imperial purple, on the throne of the Roman Caesars, crowned with the tiara on the chair of St. Peter. It has flaunted, emblazoned with the heraldries of France and England, in coronation ceremonies at Rheims and Westminster. The royal palaces of Madrid and Aranjuez tell their tales of it. So do the ruined courtyards of Granada and the castle-keep of Avignon. It shone with clear radiance in the gymnasium of Hellas, and nerved the dying heroes of Greek freedom for their last forlorn hope upon the plains of Chæronea. Endowed with inextinguishable life, in spite of all that has been done to suppress it, this passion survives at large in modern states and towns, penetrates society, makes itself felt in every quarter of the globe where men are brought into communion with men. Yet no one dares to speak of it; or if they do, they bate their breath, and preface their remarks with maledictions. Those who read these lines will hardly doubt what passion it is that I am hinting at. _Quod semper ubique et ab omnibus_--surely it deserves a name. Yet I can hardly find a name which will not seem to soil this paper. The accomplished languages of Europe in the nineteenth century supply no term for this persistent feature of human psychology, without importing some implication of disgust, disgrace, vituperation. Science, however, has recently--within the last twenty years in fact--invented a convenient phrase, which does not prejudice the matter under consideration. She speaks of the "inverted sexual instinct"; and with this neutral nomenclature the investigator has good reason to be satisfied.