Its surface is overspread with undulating sand-hills, of from 20 to ioo ft.
This peculiar feature is explained as the result of displacement of the river from a better graded preglacial valley by the Pleistocene ice-sheet, which here overspread the plains from the moderately elevated Canadian highlands far on the north-east, instead of from the much higher mountains near by on the west.
The branch of the Franks - who were a confederacy, not a people - which gradually overspread Gallia Belgica, bore the name of the Salian Franks..
Already before Alexander pan-hellenic feeling had in various ways overridden the internal divisions of the Greek race, but now, with the vast mingling of Greeks of all sorts in the newlyconquered lands, a generalized Greek culture in which the old local characteristics were merged, came to overspread the world.
It is in such localities that we can best observe the last relics of the glaciers that once overspread the country.