{Malay { 26 " m. } 1414 1223 191 { { 2 " f. } Semi-Civilized { {Aino { 87 " m. } 1462 1308 154 { { 64 " f. } Lowest Race { 22 " m. } 1277 1139 138 (10.8%) Weddas { 10 " m. } CHAPTER VII SEXUAL EVOLUTION The evolution of every living being is twofold. We must distinguish: (1) its _ontogeny_, or the entire cycle of development of the individual from its conception till natural death at an advanced age; (2) its _phylogeny_, or the series of organic forms through which its ancestors passed, by successive transformations, from the primitive cells of the oldest and most obscure geological periods, up to its present organization. In its chief outlines ontogeny is determined by phylogeny by means of the laws of heredity, even when it is only an abridged recapitulation. Regarded from this point of view the sexual life of man is also based on phylogenetic conditions, determined by his ancestral lineage. Moreover, it presents an individual or ontogenetic evolution during the life of each person, which in its principal traits is predetermined in the germ, by the phylogenetic or hereditary energies of the species. The phenomena of the hereditary mneme show clearly how ontogeny is the result of engraphia combined with selection, in the series of ancestors. We have already mentioned these points on several occasions, but must now review the whole question. PHYLOGENY OF SEXUAL LIFE In Chapter II we have briefly described phylogeny in general or metamorphosis, and in the first part of Chapter IV we have specially considered the phylogeny of the sexual appetite in the phenomenon of cell division and conjugation of nuclei in unicellular organisms, which we have described in Chapter I. In order for animals to reproduce themselves without degenerating, crossing, or the combination of different germs, is necessary, and such combinations are only possible by the mutual attraction of two kinds of germinal cells. But, when the individual becomes multicellular and bears only one kind of germinal cells, the attractive energy which was originally limited to these cells is transmitted to the whole organism, and this necessitates the existence of sensory and motor nerve centers.