HEARING. I. The Physiological Basis of Rhythm. Rhythm as a Physiological Stimulus. The Intimate Relation of Rhythm to Movement. The Physiological Influence of Music on Muscular Action, Circulation, Respiration, etc. The Place of Music in Sexual Selection among the Lower Animals. Its Comparatively Small Place in Courtship among Mammals. The Larynx and Voice in Man. The Significance of the Pubertal Changes. Ancient Beliefs Concerning the Influence of Music in Morals, Education and Medicine. Its Therapeutic Uses. Significance of the Romantic Interest in Music at Puberty. Men Comparatively Insusceptible to the Specifically Sexual Influence of Music. Rarity of Sexual Perversions on the Basis of the Sense of Hearing. The Part of Music in Primitive Human Courtship. Women Notably Susceptible to the Specifically Sexual Influence of Music and the Voice. II. Summary. Why the Influence of Music in Human Sexual Selection is Comparatively Small. VISION I. Primacy of Vision in Man. Beauty as a Sexual Allurement. The Objective Element in Beauty. Ideals of Feminine Beauty in Various Parts of the World. Savage Women sometimes Beautiful from European Point of View. Savages often Admire European Beauty. The Appeal of Beauty to some Extent Common even to Animals and Man. II. Beauty to Some Extent Consists Primitively in an Exaggeration of the Sexual Characters. The Sexual Organs. Mutilations, Adornments, and Garments. Sexual Allurement the Original Object of Such Devices. The Religious Element. Unæsthetic Character of the Sexual Organs. Importance of the Secondary Sexual Characters. The Pelvis and Hips. Steatopygia. Obesity. Gait. The Pregnant Woman as a Mediæval Type of Beauty. The Ideals of the Renaissance. The Breasts. The Corset. Its Object. Its History. Hair. The Beard. The Element of National or Racial Type in Beauty. The Relative Beauty of Blondes and Brunettes. The General European Admiration for Blondes. The Individual Factors in the Constitution of the Idea of Beauty. The Love of the Exotic. III. Beauty Not the Sole Element in the Sexual Appeal of Vision. Movement. The Mirror. Narcissism. Pygmalionism. Mixoscopy. The Indifference of Women to Male Beauty. The Significance of Woman's Admiration of Strength. The Spectacle of Strength is a Tactile Quality made Visible. IV. The Alleged Charm of Disparity in Sexual Attraction. The Admiration for High Stature. The Admiration for Dark Pigmentation. The Charm of Parity. Conjugal Mating. The Statistical Results of Observation as Regards General Appearance, Stature, and Pigmentation of Married Couples. Preferential Mating and Assortative Mating. The Nature of the Advantage Attained by the Fair in Sexual Selection. The Abhorrence of Incest and the Theories of its Cause. The Explanation in Reality Simple. The Abhorrence of Incest in Relation to Sexual Selection. The Limits to the Charm of Parity in Conjugal Mating. The Charm of Disparity in Secondary Sexual Characters.