PHYSICAL CONDITIONS— PLEISTOCENE. 361 



deposits, than the occurrence of beds of shale and sandstone 

 upon the top of Mountain-limestone proves those to be Post- 

 Carboniferous. To demonstrate the postglacial age of Palaeo- 

 lithic man, we must show that his relics and remains occur in 

 true postglacial deposits — that is to say, in beds which have 

 accumulated since the disappearance of the last great extension 

 of glacier-ice in Europe. But, as I shall point out in subsequent 

 chapters, there is no case on record of such an occurrence. 

 Neither of Palaeolithic man nor of the southern mammalia — the 

 elephants, rhinoceroses, hippopotamuses, etc. — has a single trace 

 been met with in any postglacial deposit. The most recent 

 accumulations in which such traces appear are clearly of inter- 

 glacial a<?e. Thus in Scotland remains of the more characteristic 

 Pleistocene mammals are met with underneath the upper or 

 youngest boulder-clay, as at Crofthead, and the same is the case 

 in England, as near Hull ; nowhere do they rest upon that 

 boulder-clay or upon any of the marine clays with arctic shells 

 of the Scottish maritime districts. In Central Europe, as at 

 Tempelhof in Brandenburg and Utznach in Switzerland, they 

 are in like manner covered by morainic materials. The 

 same is the case in Italy, as at Leffe in the Val Gandino, and 

 Pianico in the Val Borlezza. Then let us recall the fact that 

 while the relics of Palaeolithic man and the remains of his 

 congeners are never found upon the surface of the younger 

 or valley-loss, they yet frequently occur in and underneath that 

 deposit ; while, in all the ancient river-drifts of Southern 

 England and France, the evidence is no less clear that great 

 and tumultuous floods occurred towards the close of the Palaeo- 

 lithic Period — the mud and loam from which invariably overlie 

 the gravels containing Palaeolithic relics. Again, this is in 

 perfect harmony with the fact that in many caves, both in 

 England and the Continent, the Palaeolithic beds are covered 

 with a more or less continuous and thick • cake of stalagmite — 

 which points to the lapse of a long period of time during which 

 the caves remained unvisited either by man or beast. Take 

 also in connection with this the frequent occurrence, upon the 



