CHAP. vi.J RIVER-DRIFT MAN AND GLACIAL PHENOMENA. 171 



the north, the valley gravels are composed to a consider- 

 able extent of debris washed out of the boulder clays, 



FIG. 39. Flint Hache, Hoxne, . 



and are therefore later ; some of the Palaeolithic imple- 

 ments are made of ice-borne quartzites. It may there- 

 fore be concluded that man was probably pre-glacial 

 and glacial in Europe, but certainly post-glacial in the 

 area north of the Thames. 1 



1 Dr. James Geikie's view (The Great Ice Age) that the Palaeolithic river- 

 strata are " interglacial," in the sense of belonging to a warm period inter- 

 vening between two periods of extreme cold, is unsupported by any evidence 

 except that of Brandon and the neighbourhood now under discussion. If 

 that be allowed to pass unchallenged, it does not follow that the river strata 

 containing similar remains in southern England and France are also " inter- 

 glacial." It is probable that glaciers descended from the mountains of Scot- 

 land and of all the higher hills of Great Britain, then lifted up at least 

 600 feet above their present levels into the colder regions of the air, as 

 well as from the Alps, Pyrenees, and hilly region of Auvergne, while the 

 mammalia were living in the forests and prairies below ; but there is no 



