GEOGRAPHICAL EVOLUTION 363 



to have sunk down ; for we find that one wide sea extended 

 across the whole of Central Europe and Asia. It was at 

 the close of this period of extreme depression that those 

 subterranean movements began to which the present con- 

 figuration of Europe is mainly due. The Pyrenees, Alps, 

 Apennines, Carpathians, the Caucasus, and the heights of 

 Asia Minor mark, as it were, the crests of the vast earth- 

 waves into which the solid framework of Europe was then 

 thrown. So enormous was the contortion that, as may be 

 seen along the northern Alps, the rocks for thousands of 

 feet were completely inverted, this inversion being accom- 

 panied by the most colossal folding and twisting. The mas- 

 sive sedimentary formations were crumpled up, and doubled 

 over each other, as we might fold a pile of cloth. In the 

 midst of these commotions the west of Europe remained 

 undisturbed. It is strange to reflect that the soft clays and 

 sands under London are as old as some of the hardened 

 rocks which have been upheaved into such picturesque 

 peaks along the northern flanks of the Alps. 



After the completion of these vast terrestrial disturb- 

 ances, the outlines of Europe began distinctly to shape 

 themselves into their present form. The Alps rose as a 

 great mountain range, flanked on the north by a vast lake 

 which covered all the present lowlands of Switzerland, and 

 stretched northward across a part of the Jura Mountains, 

 and eastward into Germany. The size of this fresh-water 

 basin may be inferred from the fact that one portion only 

 of the sand and gravel that accumulated in it even now 

 measures 6000 feet in thickness. The surrounding land 

 was densely clothed with a vegetation indicative of a much 

 warmer climate than Europe now can boast. Palms of 

 American types, as well as date palms, huge Californian 

 pines (Sequoia), laurels, cypresses, and evergreen oaks, 

 with many other evergreen trees, gave a distinctive charac- 

 ter to the vegetation. Among the trees too were planes, 

 poplars, maples, willows, oaks, and other ancestors of our 

 living woods and forests; numerous ferns grew in the 

 underwood, while clematis and vine wound themselves 

 among the branches. The waters were haunted by huge 

 pachyderms, such as the dinotherium and hippopotamus; 



