DRIFT-BEDS. 231 



gravel-beds and moraiues put back again on the mountains from 

 which they were removed, there were would be a great increase 

 of height to the Alpine range. 



Traces of Man and of his works are found in Switzerland in 

 the higher stratum of the country, in peat-bogs and tufas which 

 are continually increasing. Prof. Heer does not consider that 

 there are any such traces in the drift gravel-beds lying beneath 

 the soil which contains the remains of the inhabitants of pile- 

 dwellings. The plants of this epoch almost exactly resemble 

 those of the present day, and the fauna only offers us a few ex- 

 otic types ; if, however, the Miocene rocks are examined which 

 lie immediately below these drift gravel-beds in Switzerland, 

 another world of life meets the view. As the glaciers and gra- 

 nulated-snow fields which encircle the Alpine chain with a white 

 girdle constitute a boundary-line for animal and vegetable life, 

 the glaciers of the first drift-period form a far more important 

 barrier between the drift and the Tertiary fauna and flora. 



Even the rocks which contain their remains are very different. 

 The drift deposits consist chiefly of pebbles and sand, here and 

 there, indeed, united into solid masses, but not forming true 

 rocks ; whilst the Tertiary deposits have largely assisted in the 

 formation of mountains. Descending still lower, we meet with 

 a long series not only of different rock-formations, but also of 

 different animals and plants, succeeding one another step by 

 step ; so that when a general survey is made, a world is revealed 

 to us rich in organized beings which formerly lived upon the 

 earth, and we ascertain that Switzerland contains memorials of 

 all periods from the drift to the coal-formation. Below the 

 anthracite rocks which represent the Carboniferous period, 

 crystalline rock-masses are found, which have been essential to 

 the construction of the Alps, and which consist of numerous 

 varieties of granite and gneiss, micaceous, chloritic, and talcose 

 schists, and amphibole"*. Quartz, felspar, and mica are the 

 constituents of granite and gneiss, the latter being distinguished 

 from granite by its stratification. In the mica-schist mica pre- 



* [Amphibole comprises hornblende, actinolite, treinolite, &c. (Lyell's 

 ' Elements of Geology,' chapter 28). EDITOR.] 



