_Hybridity._—The intermixture of human races or stocks, human hybridity as it is sometimes called, has been recognised by all anthropologists to be a prime factor in ethnic psychology, in the psychical history of Man. But, strange to say, the opinions about its results could not have been more divergent. On the one hand we have a corps of authors, Gobineau, Nott, Broca, Hovelacque, Hervé, etc., who condemn the admixture of human races as leading inevitably to mental and physical degeneration, infertility, and extinction. In direct contradiction to them we find the not less distinguished names of Quatrefages and Bastian, who maintain not only that such “miscegenation” is harmless, but that it has been the main factor of human intellectual progress! That owing chiefly to it certain tribes and nations have by unconscious selection drawn to themselves the strong qualities of many lines of blood, and thus won the foremost place in the struggle for existence. This was notably the opinion of Quatrefages, who defended the thesis, “In race-mingling the crossing is unilateral and is directed under unconscious selection toward the superior race.” This is supported by many well-known examples. In our own country, the superiority of the mulatto to the full-blood negro is proved by history and is familiar to all observers; and Dr. Boas has shown by statistical researches that the half-blood Indian is mentally superior to his companion of pure lineage, while the half-blood Indian women, instead of revealing diminished fertility, average two more children to a marriage than their red sisters of unmixed lineage. But it will not do to ignore the array of facts of contrary tenor which has been marshalled to show that in divers instances the result of race-mixture has been disastrous. Many of these may easily be explained by the unfortunate social condition of children in such unions, mostly illegitimate, or at odds with extreme poverty and its ill surroundings. If they do inherit an increased ability, it is, under modern conditions, more apt to be directed against than in favour of the social order. After all such allowances, there remains a residue unexplained by them, and inconsistent with the general theory of advantage in race-intermixture. The solution of this problem is to be found in the operation of an obscure but certain law of heredity which has been demonstrated by the best modern observers. This reads that in the struggle for transmission between contrary characteristics in the parents, any trait, mental or physical, may be passed down separately, _independently of others_. Thus, on the physical side, the father may have red, the mother black, hair. The children will inherit, not a blended colour, but some the red, some the black hair. Or, let us say, one parent has marked musical ability, the other none. Some of the children will have as much as the gifted parent, the others be devoid of the faculty.