INVITATION TO HEIDELBERG. 211 



lively, clear, and attractive method of teach- 

 ing awakened their own powers of observa- 

 tion in his little pupils, and to some at least 

 opened permanent sources of enjoyment. 



His instructions to his older pupils were 

 based on the same methods, and were no less 

 acceptable to them than to the children. In 

 winter his professional courses to the students 

 were chiefly upon zoology and kindred topics ; 

 in the summer he taught them botany and 

 geology, availing himself of the fine days for 

 excursions and practical instruction in the 

 field. Professor Louis Favre, speaking of 

 these excursions, which led them sometimes 

 into the gorges of the Seyon, sometimes into 

 the forests of Chaumont, says : " They were 

 fete days for the young people, who found in 

 their professor an active companion, full of 

 spirits, vigor, and gayety, whose enthusiasm 

 kindled in them the sacred fire of science." 



It was not long before his growing reputa- 

 tion brought him invitations from elsewhere. 

 One of the first of these was from Heidelberg. 



PROFESSOR TIEDEMANN TO LOUIS AGASSIZ. 



HEIDELBERG, December 4, 1832. 

 . . . Last autumn, when I had the pleasure 

 of meeting you in Carlsruhe, I proposed to 



