448 NINETEENTH CENTURY. PT. III. 



for himself, but for the work he longed to complete ; while 

 his gratitude is so sensible and heartfelt towards those who 

 helped him to bring out his splendid additions to the 

 science of zoology. His was a warm-hearted, earnest, and 

 active nature, and he was beloved by all who knew him. 

 It is pleasant to think that the Americans, among whom he 

 spent the latter half of his life, from 1846 to 1874, ap- 

 preciated him fully. In 1867, by the kindness of Mr. 

 Thayer, he was able to make a most important journey of 

 discovery in Brazil ; and up to the last years of his life he 

 continued to train up young naturalists to carry on his 

 favourite studies. 



Agassiz proves that parts of modern Europe and 

 North America must once have been covered with 

 Great Fields of Ice, 1840. It is, however, of the early 

 part of Agassiz's life, while he was still in Switzerland, that 

 we must now speak. Although his chief study was zoology, 

 yet he could not live at Neuchatel, and travel about the 

 Alps, without being struck with those mighty rivers of ice , 

 called glaciers, which creep slowly down the valley of the 

 Alps in Switzerland, carrying with them stones and rubbish. 

 (See Fig. 74, p. 449.) 



These glaciers are formed by the snow, which collects 

 on the tops of high mountains, and sliding down, becomes 

 pressed more and more firmly together as it descends into 

 the valleys, until it is moulded into solid ice, creeping 

 slowly onwards between the mountains, and carrying with it 

 sand, stones, and often huge pieces of rock which fall upon 

 it. At last one end of this ice-river reaches a point where 

 the air is warm enough to melt it, and here it flows gradually 

 away as water, leaving the stones and rubbish it has brought 

 down lying in a confused heap, which is called a moraine. 



Towards the end of the eighteenth century a famous 



