Y N beginning this inquiry into the nature and manifestations of the sex-impulse—by far the most difficult part of my present task— I seek indulgence in the fact that, up to a very recent period, practically nothing was known technically on the subject; and that, notwithstanding the valuable contributions of Krafft-Ebing, Ellis, Moll, and other modem writers, to the scientific literature of the subject, we are yet sufficiently ignorant of the real status of sexuality as to inspire considerable doubt concerning even its correct classification in the list of observed phenomena.

1$ the sexual act a propagaiive instinct, or a mere excretory function of nature T This is the important question which confronts us at the very-threshold of our investigation, and one concerning which, I regret to say, even our latest and ablest literature leaves us largely in doubt.

Most writers epeak of the "sexual instinct;" but a true definition of instinctive action would seem to exclude that sexual activity which underlies the phenomenon of procreation; since, under most conditions, the sexual act is one of volition, and deliberation, quite as much as of impulse; and since, in a state of nature, the other excretory functions of the body, such as micturition, defecation, etc., are quite as imperious, if somewhat different in their manifestation.

Herbert Spencer's definition of instinct, however, as "a compound reflex action," is sufficiently comprehensive and clear, notwithstanding Pumell's objection,1 to answer our present purpose. What we call instinct, the term being a generic one, and comprising all those faculties of mind which lead to the conscious performance of actions, adaptive in character, but not pursued with a knowledge of their results, would seem, naturally, to exclude all acta performed with such a definite knowledge; and to be confined wholly to those spontaneous animal manifestations which are not associated in any way with conscious purpose, or, what Pierre Huber calls the "little dose of reason." But, on the other hand, if that be an instinct which prompts or underlies "those complex groups of co-ordinated acts, totally independent of previous experience," as Prof. Lloyd Morgan remarks,1 "but which are subject to variation, and subsequent modification, under the guidance of experience," we may reasonably agree with Gamier, Tillier and others, in the recognition of a true "sexual instinct."