108 EMINENT NATURALISTS. 



ablest men in all departments of science. He proved 

 unmistakably that in the position of the visible parts 

 of the earth as they stand, water had been an agent 

 in a form before scarcely thought of and to an extent 

 before not apprehended. He showed that in the form 

 of vast rivers of ice it had modified the terrestrial 

 surface most materially in places where the climate 

 no longer permits of such action. The discoveries of 

 Agassiz also gave an explanation for the existence 

 of boulders or large water-worn stones, in positions 

 far above the reach, nowadays, of the agencies to 

 which they must have been at one time subjected. 



From 1846 the biography of Agassiz belongs to 

 the natural history of the United States. At the 

 suggestion of Mr. (afterwards Sir) Chas. Lyell, Mr. 

 (now Hon.) John A. Lowell had, in 1845, invited 

 Professor Agassiz to Boston, to deliver a course of 

 lectures before the Lowell Institute. The Bostonians 

 claim, and with reason, to represent the best of American 

 intellectual life, so that this was no slight compliment. 

 About the same time that the invitation reached 

 Agassiz, the King of Prussia, through the ever- 

 thoughtful mediation of Humboldt, had presented 

 him with a sum of money in aid of a scientific 

 mission to America. Thus encouraged by invitation 

 and by pecuniary aid, he crossed the Atlantic in the 

 autumn of 1846, and made his debut in the United 

 States as a lecturer. His first lectures were on the 

 subject of Comparative Embryology, and they were 

 listened to by audiences of from 1,500 to 2,000, 

 embracing all that was most cultivated in science and 



