236 PREHISTORIC EUROPE. 



inundated ; and this inundation -water is not a tumultuous 

 raging torrent, but very frequently assumes the aspect of a wide 

 lake-like expanse of quiet water, from which fine sediment is 

 deposited, forming a film of mud more or less continuous. It 

 is only here and there that we observe coarse sand and gravel 

 strewn over the fields to mark the course taken by the thread 

 of the current, which eventually succeeded in draining the 

 flooded area. 



The homogeneous character of the Bhenish and Danubian 

 loss is well explained by this theory of its origin. Composed in 

 chief measure of the fine silt derived from the glaciers of the 

 Alps, it is not surprising that it should show such a sameness in 

 all the great valleys which were charged with water descending 

 in vast volumes from the glaciated areas. The waters of the 

 Rhine invaded the lower reaches of most of its tributary valleys, 

 and deposited there the same kind of mud as that which accumu- 

 lated in the main line of drainage. But farther up these lateral 

 valleys the mud would assume more of a local character, com- 

 posed as it would be of materials derived from the disintegration 

 and denudation of the adjacent rocks. In other regions, such as 

 the plateaux of Northern France and the low grounds of 

 Southern England, mud and silt would likewise be widely dis- 

 tributed, but these would be derived chiefly from the wash of 

 the Cretaceous and other strata by rain, by the water coming 

 from melting snow, and in the valleys doubtless by deeply- 

 flooded streams and rivers. But it is in those regions that 

 drained more or less directly from glacier-regions where we find 

 the deepest and broadest accumulations of loamy deposits. The 

 Garonne was flooded by the melting snow and ice of the 

 Pyrenees, the Bhone by the waters coming from the vast ice- 

 fields of the Alps, the Saone by those derived from the Jura, the 

 Seine by the dissolving snow and ice of the Morvan and neigh- 

 bouring hilly tracts. Muddy inundations likewise choked many 

 of the valleys of the Carpathians, and a like fate befell such 

 valleys as those of the Drave and the Save that received the drain- 

 age of the Eastern Alps. On the south side of the Alps there was 



