Page:Popular Science Monthly Volume 48.djvu/742

670 Always, in accounting for such a phenomenon, two factors are to be considered—race and environment. Hence, in our study of climatic circumstances the first must be carefully eliminated before proceeding to study the second.

Finally, the effects of ethnic intermarriage or crossing must in every case be taken into account. It is present as a complication in almost all colonial populations, and is by far the most subtle and difficult of all eliminations to be made. Notwithstanding the objection that accommodation to climate by intermarriage is in reality not acclimatization at all, but the formation of an entirely new type, the two are continually confused; and crossing with native stocks is persistently brought forward as a mode and policy of action. As an element in colonization, and a devious means of avoiding the necessity of acclimatization, it arises to complicate the situation. Intermarriage is said to be the secret of Spanish and Portuguese success; in Mexico this has apparently been the case, as well as in the Philippines. Dr. Bordier states that the Spanish and southern French are more prolific than others in marriage with negroes; and concludes that the only hope for the future of French colonization in Cochin China lies in such crossing with the natives. The efficacy of this remedy is to-day accepted quite generally by anthropologists. Topinard agrees with Ten Kate that half-breeds resist climatic changes better than pure whites, and other authorities concede the same. Desmartis has even proposed to inoculate the British troops in India with Hindu blood as a preventive of tropical disorders.