33o PREHISTORIC EUROPE. 



tions of such conditions having alternated may point rather to 

 secular than to mere seasonal changes — the " white drift," with 

 its large angular blocks, representing the upper limestone-breccias 

 of Gibraltar, and the moraines of the latest glacial epoch in the 

 Alps and Northern Europe. 1 



The facts now adduced demonstrate to us that the so-called 

 Glacial Period was interrupted more than once by interglacial 

 epochs of long continuance, during which the Pleistocene mam- 

 malia occupied the low grounds vacated by the glaciers and the 

 great mer de glace ; elephants, rhinoceroses, and hippopotamuses 

 living then as far north as England and North Germany. Palaeo- 

 lithic man, as we now know, was also an interglacial resident in 

 England and Switzerland, and doubtless of many other parts of 

 Europe at the same time. The climate of those interglacial 

 epochs was certainly not less genial than that of the present ; 

 indeed, if we may judge from the assemblages of plants and 

 animals which occur in the Swiss, Italian, French, and German 

 deposits, it would seem to have been remarkably equable, the 

 seasons not being so strongly contrasted as they are now. In 

 a word, the climatic conditions appear to have been of the same 

 character as those during which the tufas and travertines of 

 Tuscany, France, and Germany were accumulated. Thus just 

 as we found reason for concluding that the Pleistocene river- 

 and cave-deposits, with their arctic and alpine fauna, must have 

 been contemporaneous with the former much greater extension 

 of snow-fields and glaciers in Europe, so does the conviction 

 grow upon us that the laurels and fig-trees of Northern France, 

 and the hippopotamuses and elephants so generally distributed 

 through the Pleistocene beds of North-western Europe, must be 

 synchronous with the flora and fauna of interglacial ages. 



1 Coarse limestone-breccias are well known to occur in various places through- 

 out the Mediterranean region, the origin of which has never been satisfactorily- 

 accounted for. They are not forming now, but are being furrowed and worn away, 

 •just like the limestones upon or near to which they repose. That many of them 

 date back to Pleistocene times is not disputed ; what more likely, then, than 

 hat they are the southern representatives of our glacial deposits ? 



