CAUSE OF MILD POLAR CLIMATES. 173 



is also well known, is found in the " Flysch" of 

 Switzerland. On the north side of the Alps, from 

 Switzerland to Vienna, and also near Genoa, there is a 

 sandstone a few thousand feet in thickness, containing 

 enormous blocks of Oolitic limestone and granite. 

 Many of these blocks are upwards of 10 feet in length, 

 and one at Halekeren, near the lake of Thun, is 105 

 feet long, 90 feet broad, and 45 feet in thickness. The 

 block is of a granite of a peculiar kind, which cannot 

 be matched anywhere in the Alps. Similar blocks are 

 found in beds of the same age in the Appennines and 

 in the Carpathians. The glacial origin of this deposit 

 is further evinced by the fact that it is wholly destitute 

 of organic remains. One circumstance, which indicates 

 that this glaciation was due to eccentricity, is the fact 

 that the strata most nearly associated with the 

 "Flysch''' 'are rich in Echinoderms of the Spatmigus 

 family, which have a decided tropical aspect. This is 

 what we ought, of course, a priori, to expect if the 

 glaciation was the result of eccentricity, for the more 

 severe a cold period of a glacial epoch is, the warmer 

 will be the periods which immediately precede and 

 succeed. 



Some writers endeavour to account for those glacial 

 phenomena, without any reference to the influence of 

 high eccentricity, by the assumption that the Alps were 

 much more elevated during the Tertiary period than 

 they are at the present day. If we, however, adopt 

 this explanation, we shall have to assume that the 

 Alps were suddenly elevated at the time when the bed 

 containing the erratics began to be deposited, and that 

 they were as suddenly lowered when the deposition of 

 the bed came to a close — a conclusion certainly very 

 improbable. Had the lowering of the Alps been 

 effected by the slow process of denudation, it must 



