an organ of voluptuous sensation -- Erogenic areas of skin -- The kiss -- Its erotic significance -- An Arabian poet (Sheik Nefzawi) on this subject -- Burdach’s definition of the kiss -- The kiss on the boundary-line between erotism and actual sexual enjoyment -- The origin of the kiss -- The primitive elements of contact, licking and biting -- Its connexion with the nutritive impulse -- European origin of the kiss of contact -- The smelling kiss of the Mongols -- The kiss and sexuality -- Voltaire’s genito-labial nerve -- The sense of taste and sexuality -- The preponderant importance of the higher senses in the love of civilized man -- The beautiful explanation of Herder -- Liberation from the material in the higher senses -- The sense of sight as the true æsthetic sense -- Beauty as the product of love -- Its perception by the sense of sight -- Rôle of the sense of hearing in love -- The investigations of Darwin -- The voice as a sexual lure -- The rhythmical repetition of alluring sounds -- Origin of song and music -- Greater susceptibility of women to impressions received through the sense of hearing -- The charm of woman’s voice -- An experience of the natural philosopher Moreau. CHAPTER II As we have learnt in the first chapter, the primitive phenomenon of sexual attraction and reproduction, the conjugation of the male and the female germinal cells, persists unaltered in man as the most important part of the act of procreation; but this process of “fusion-love” derived by inheritance from unicellular organisms, is associated in man with a number of new secondary physical and psychical phenomena of sexuality. This inevitably results from the nature of the human organism as a cell society, from the development of man as one of the order of mammalia, and finally from man’s elevation above the other mammalia as a being of enormously enhanced brain powers. The complex of these secondary physical and psychical phenomena of love, dependent upon the process of evolution, has, as we have already said, been denoted by W. Bölsche by the apt name of “distance-love,” which he thus distinguishes from the primary elemental phenomenon of “fusion-love.” These superadded elements play an extremely important part in human civilization, and, indeed, actually characterize that civilization which is in no way dependent on the primitive qualities shared by man with plants and lower animals.