Names like Cis-Alpine and Trans-Alpine Gaul in the Roman Empire, Trans-Caucasia, Trans-Caspia and Trans-Baikalia in the Russian Empire, the Transvaal and Transkei in South Africa, indicate the direction whence the advancing people have come.
[Sidenote: Stratification of races] Ethnology reveals an east and west stratification of linguistic groups in Europe, a north and south stratification of races, and another stratification by altitude, which reappears in all parts of the world, and shows certain invading dominant races occupying the lowlands and other displaced ones the highlands.

This definite arrangement points to successive arrivals, a crowding forward, an intrusion of the strong into fertile, accessible valleys and plains, and a dislodgment of the weak into the rough but safe keeping of mountain range or barren peninsula, where they are brought to bay.

Ethnic fragments, linguistic survivals, or merely place names, dropped like discarded baggage along the march of a retreating army, bear witness everywhere to tragic recessionals.
[Sidenote: The name Historical Movement.] Every country whose history we examine proves the recipient of successive streams of humanity.

Even sea-girt England has received various intruding peoples from the Roman occupation to the recent influx of Russian Jews.

In prehistoric times it combined several elements in its population, as the discovery of the "long barrow" men and "round barrow" men by archaeologists, and the identification of a surviving Iberian or Mediterranean strain by ethnologists go to prove.[126] Egypt, Mesopotamia, and India tell the same story, whether in their recorded or unrecorded history.