S46

CHRONOLOGICAL RELATIONS

CHAP. XII.

It often happens that when in any given region we havepushed back our geological investigations as far as we can, insearch of evidence of the first appearance of Man in Europe ,we are stopped by arriving at what is called the ‘ boulder-clay’ or ‘northern drift.’ This formation is usually quitedestitute of organic remains, so that the thread of our in-quiry into the history of the animate creation, as well as ofman, is abruptly cut short. The interruption, however, is byno means encountered at the same point of time in everydistrict. In the case of the Danish peat, for example, weget no farther back than the recent period of our Chrono-logical Table (p. 5), and then meet with the boulder-clay,and it is the same in the valley of the Clyde, where themarine strata contain the ancient canoes before described(p. 51), and where nothing intervenes between that recentformation and the glacial drift. But we have seen that, inthe neighbourhood of Bedford (p. 214), the memorials ofMan can oe traced much farther back into the past, namely,into the pleistocene epoch, when the human race was con-temporary with the mammoth and many other species ofmammalia now extinct. Nevertheless, in Bedfordshire as inDenmark , the formation next antecedent in date to thatcontaining the human implements is still a member of theglacial drift, with its erratic blocks.

If the reader remembers what was stated in the ninthchapter, p. 190, as to the absence or extreme scarcity ofhuman bones and works of art in all strata, whether marineor freshwater, even in those formed in the immediateproximity of land inhabited by millions of human beings,he will be prepared for the general dearth of human me-morials in glacial formations, whether recent, pleistocene orof more ancient date. If there were a few wanderers overlands covered with glaciers, or over seas infested with ice-bergs, and if a few of them left their bones or weapons in