The interpretation of all this was obviously that the land had been tenanted a long time ago by Negroes, that an invasion of Bushmen drove the Negroes to the hills, and that the supremacy of these lasted so long that the Negroes lost their own language and acquired that of the Bushmen. Then an invasion of a tribe of Bantu race supplanted the Bushmen, and the Bantus, after endless struggles among themselves, were being pushed aside at the time I visited them by the incoming Namaquas, who themselves are a mixed race. This is merely a sample of Africa; everywhere there are evidences of changing races.
The last 300 or 400 years, say the last ten generations of mankind, have witnessed changes of population on the largest scale, by the extension of races long resident in Europe to the temperate regions of Asia, Africa, America, and Australasia.
Siberia was barely known to the Russians of nine generations ago, but since that time it has been continuously overspread by their colonists, soldiers, political exiles, and transported criminals; already some two-thirds of its population are Sclaves.
In South Africa the settlement at the Cape of Good Hope is barely six generations old, yet during that time a curious and continuous series of changes has taken place, resulting in the substitution of an alien population for the Hottentots in the south and the Bantus in the north. One-third of it is white, consisting of Dutch, English, descendants of French Huguenot refugees, some Germans and Portuguese, and the remainder is a strange medley of Hottentot, Bantu, Malay, and Negro elements. In North Africa Egypt has become infiltrated with Greeks, Italians, Frenchmen, and Englishmen during the last two generations, and Algeria with Frenchmen.
In North America the change has been most striking, from a sparse Indian population of hunters into that of the present inhabitants of the United States and Canada; the former of these, with its total of fifty millions inhabitants, already contains more than forty-three millions of whites, chiefly of English origin; that is more of European blood than is to be found in any one of the five great European kingdoms of England, France, Italy, Germany, and Austria, and less than that of Russia alone. The remainder are chiefly black, the descendants of slaves imported from Africa. In the Dominion of Canada, with its much smaller population of four millions, there has been a less, but still a complete, swamping of the previous Indian element by incoming whites.