196 GLACIAL HISTORY. 



were carried down to the lower regions both upon the glacier 

 of the Lake of Wallenstadt and on that of the Rhine. The 

 moraines coming from the Prattigau and Montafun remained 

 upon the right side of the Rhine, where they formed a long 

 lateral moraine. The other valleys of the Orisons also furnished 

 abundant materials, which now form an important part of the 

 soil in the Cantons of Thurgovia and St. Gall, and furnish nu- 

 merous round and flat pebbles below Constance. 



On the southern slope of the Alps all the phenomena of gla- 

 ciers observed on the northern side recur. A great glacier 

 descended from the Canton of Tessin into the plain of Lombardy, 

 and filled the basin of the Lago Maggiore. A second glacier 

 came from the Spliigen and the valley of Bergell, and, uniting 

 with the glacier of the Valteline, formed a bridge over the lake 

 of Como, and pushed forward its terminal moraine into the 

 neighbourhood of Monza. The beautiful peninsula of Bellaggio 

 enclosed on both sides by the Lake of Como, is dotted over with 

 rocks which can only have been derived from the Alps. Even 

 the Lago di Garda, on the smiling shores of which now bloom 

 the orange and the citron, was once covered with an icy glacier, 

 upon which were borne along great masses of Alpine debris, 

 covering the country to beyond Peschiera. The glacier of 

 Monte Rosa advanced the farthest towards the south ; breaking 

 forth from the narrow valley of Aosta, it spread over the plain 

 near Ivrea, and as far as Caluso covered the ground with Alpine 

 debris, which now form the chain of hills rising from the plain 

 to an elevation of as much as 1500 feet, and resting on the 

 marine Pliocene formation. 



In the glacial period of the development of the earth a thick 

 icy crust spread over not only the Swiss mountain- country of 

 Central Europe, but extended itself to the northern part of the 

 continent, and advanced to the sea, where it pushed out and 

 formed innumerable floating icebergs. By these glaciers and 

 icebergs immense masses of rock were brought from Scandinavia 

 and the north of Russia into Northern Germany, where they 

 now rise here and there in the form of low ranges of hills above 

 the vast sandy plains of that empire. Scotland and a part of 

 England were likewise covered with glaciers, upon the extension 



