LECTURE XI. 325 



hundred feet atove tlie Baltic^ must haye been connected with 

 this ice sea, as several species of Crustacea still inhabit these 

 lakeSj the relics of this ice population. Already, in 1846, my 

 friend Desor had proved, in a treatise, that there prevails the 

 greatest analogy between the phenomena in the north and those 

 of the Alps, and that the peculiarities which distinguish the 

 northern phenomena are due to the alterations in the level, by 

 ■which the sea on the Scandinavian coasts rose, then again gra- 

 dually subsided down to the present time, during which the 

 elevation of the Scandinavian soil is still continuing. During 

 the last period there were formed, as in Switzerland, here and 

 there, glacial necks, which produced those confusedly stratified 

 ridges upon the surface of which lie angular blocks known by 

 the name of " Oesars." In the interior of the high valleys, 

 just as in the lake basins of Switzerland, were heaped up mo- 

 raines, which at times attain a great size. All this has been 

 confirmed by Martins, so that we can add nothing fresh as re- 

 gards the north. 



The process was the same in the North-American continent, 

 with this difference, that but little of the l^d was there sub- 

 merged under the sea, but large fresh water-lakes were formed, 

 the deposits of which prove that the present lakes on the Ca- 

 nadian boundary are only the remnants of the inland fresh 

 water lakes. 



On turning to England, we find an analogous series of phe- 

 nomena. At the bottom, boulder-clay resting here and there 

 upon fresh water formations, alluvium, and pebbles ; above 

 them, in the mountainous regions, as in Scotland and Wales, 

 moraines testifying of glaciers which descended into the valleys. 

 Everywhere the same phenomena in the same succession, only 

 so far modified, that in the north it is the sea, in the south it 

 is the fresh water which predominates in its action. 



The following table shows on the one hand the synchronism 

 of the glacial clay in different countries, and on the other hand 

 the synchronous appearance of the mammoth {Mephas 2>rimi- 

 genius), and the rhinoceros tichorhinus, which in some parts of 

 the European continent were the contemporaries of man. 



