It must not be supposed that emigration on a large scale implies even a moderate degree of civilisation among those who emigrate, because the process has been frequently traced among the more barbarous tribes, to say nothing of the evidence largely derived from ancient burial-places. My own impression of the races in South Africa was one of a continual state of ferment and change, of the rapid development of some clan here and of the complete or almost complete suppression of another clan there. The well-known history of the rise of the Zulus and the destruction of their neighbours is a case in point. In the country with which I myself was familiar the changes had been numerous and rapid in the preceding few years, and there were undoubted signs of much more important substitutions of race in bygone times. The facts were briefly these: Damara Land was inhabited by pastoral tribes of the brown Bantu race who were in continual war with various alternations of fortune, and the several tribes had special characteristics that were readily appreciated by themselves. On the tops of the escarped hills lived a fugitive black people speaking a vile dialect of Hottentot, and families of yellow Bushmen were found in the lowlands wherever the country was unsuited for the pastoral Damaras. Lastly, the steadily encroaching Namaquas, a superior Hottentot race, lived on the edge of the district. They had very much more civilisation than the Bushmen, and more than the Damaras, and they contained a large infusion of Dutch blood. 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.