2 6o PREHISTORIC EUROPE. 



life also made its appearance. The remains in the peat, so 

 far as they have yet been examined, would lead one to infer 

 somewhat temperate climatic conditions. It is true that from 

 this particular bed no bones, horns, or teeth of any mammalia 

 have come, but the presence of large animals in the country is 

 suggested by the occurrence of Geotrupes stercorarius, a dung- 

 feeding species. The peat itself appears to consist largely of 

 twigs and branches — a good deal decomposed ; and from the 

 presence of rootlets penetrating the underlying sandy silt we 

 may suppose that we have here an old land -surface. From 

 the general appearance of the beds it might be inferred that 

 they mark the margin and bed of a shallow lake, or that they 

 were accumulated in some lake -like expansion of a stream. 

 In Fig. 7 we observe how the underlying " alpine diluvium " 

 has been denuded and washed — the finer materials having been 

 removed and the large stones left behind. We may suppose 

 that the peat which gathers round and over these stones repre- 

 sents the marshy bank of the old lake or stream. Traced in 

 some directions, the peat died out and was succeeded, as I 

 have said, by silt, sand, and clay — deposits evidently contem- 

 poraneous with the peat, and indicating either a lake-bottom or 

 the bed of some quiet back-water in a stream. In short, we 

 have here evidence of a land-surface supporting trees, and of 

 streams that carried away vegetable debris and insects, and 

 buried them in its silt and sand. 



3d, The peaty bed with its overlying silt and clay is suc- 

 ceeded above by coarse earthy sand and gravel, with angular and 

 sub -angular stones and boulders which imply very different 

 conditions. The orderly deposition of fine-grained sediment in 

 quiet water was followed by the action of torrential water, and 

 the accumulation of materials of precisely the same character 

 as those which underlie the old lake-beds. To this tumultuous 

 accumulation succeeds a second mass of tough boulder-clay, 

 whose included stones prove it to have been rolled forward 

 underneath a mer de glace flowing in an easterly direction. The 

 phenomena presented by this till lead to precisely the same 



