The human complement of instincts fluctuates from one individual to another in an apparently endless diversity, varying both in the relative force of the several instinctive proclivities and in the scheme of co-ordination, coalescence or interference that prevails among them. This diversity of native character is noticeable among all peoples, though some of the peoples of the lower cultures show a notable approach to uniformity of type, both physical and spiritual. The diversity is particularly marked among the civilised peoples, and perhaps in a peculiar degree among the peoples of Europe and her colonies. The extreme diversity of native character, both physical and spiritual, noticeable in these communities is in all probability due to their being made up of a mixture of racial stocks. In point of pedigree, all individuals in the peoples of the Western culture are hybrids, and the greater number of individuals are a mixture of more than two racial stocks. The proportions in which the several transmissible traits that go to make up the racial type enter into the composition of these hybrid individuals will accordingly vary endlessly. The number of possible permutations will therefore be extremely large; so that the resulting range of variation in the hybrids that so result from the crossing of these different racial stocks will be sufficiently large, even when it plays within such limits as to leave the generic human type intact. From time to time the variation may even exceed these limits of human normality and give a variant in which the relative emphasis on the several constituent instinctive elements is distributed after a scheme so far from the generically human type as to throw the given variant out of touch with the common run of humanity and mark him as of unsound mind or as disserviceable for the purposes of the community in which he occurs, or even as disserviceable for life in any society. Yet, even through these hybrid populations there runs a generically human type of spiritual endowment, prevalent as a general average of human nature throughout, and suitable to the continued life of mankind in society. Disserviceably wide departures from this generically human and serviceable type of spiritual endowment will tend constantly to be selectively eliminated from the race, even where the variation arises from hybridism. The like will hold true in a more radical fashion as applied to variants that may arise through a Mendelian mutation.