Within two centuries there may be less than forty languages left remaining, and less than twenty nationalities, that is to say, branches of mankind using the same tongue and deeming themselves members of the same stock.
So far we have been mainly concerned with races conspicuously differing in strength. But I now come to those cases in which the colliding peoples are so nearly matched that neither yields to and sinks beneath the other. It is here that we find the greatest variety of phenomena and the most difficult problems. It is here that the interest of the future lies, because these stronger races will be factors in history for some generations or centuries to come.
The elements of strength present in two diverse races brought into contact need not be the same elements. One race may have physical strength and courage, the other may be strong through patient industry. One may be gifted with a highly developed brain and store of knowledge: the other may possess that prolific quality which ensures an abundant offspring. Accordingly I use the term 'strength' not as implying either physical or intellectual or volitional excellence, but rather to denote the capacity of a stock to maintain itself in the struggle for life against other stocks.
When two strong races come into contact, be it hostile or pacific, there are two possible issues. The races may become mixed by intermarriage, or they may remain separate, necessarily influencing one another but not mingling their blood.
All the great peoples of the world are the result of
