Page:Popular Science Monthly Volume 48.djvu/743

Rh On the other hand, a cross between races is too often apt to be a weakling, sharing in the pathological predispositions of each of its parent stocks, while enjoying but imperfectly their several immunities, as we have seen.

Mulattoes in any climate are liable to lack vitality, and especially, unless a continual supply of white blood is kept up, they tend to degenerate. Dr. Gould notices this lack of vitality among mulattoes as very marked in the Union army. For this reason intermixture is by many regarded as a doubtful remedy. Neither the Malay nor the Japanese mixed races have the vitality of the Chinese. Jousset affirms that in many cases crossing increases the liability to attacks of fever. In Guiana the negroes thrive, but the mulattoes suffer from the climate. Berenger-Ferand states that the mulatto in Senegal so far degenerates as to become infertile after three generations; and Westermarck, while acknowledging that many statements of this kind are exaggerated, inclines to the view that crossing may be unfavorable to fertility. Be this as it may, it is certain that mulattoes are pathologically intermediate between the white and the negro; they rarely have yellow fever, and are less liable to malaria (paludism) than the Europeans; and they are not predisposed to bilious disorders. But they have all the diseases to which the negro is alone liable—namely, elephantiasis leprosy, phthisis, and even the dreaded sleeping sickness (mal de sommeil). Finally, it may be added that many of the most successful examples of acclimatization have occurred where there has been a complete