CORRESPONDENCE WITH BRA UN. 39 



BRAUN TO AGASSIZ. 



CARLSRUHE, Whitsuntide, Monday, 1827. 



... I am in Carlsruhe, and as the pack- 

 age has not gone yet, I add a note. I have 

 been analyzing and comparing all sorts of 

 plants in our garden to-day, and I wish you 

 had been with me. On my last sheet I send 

 some nuts for you to pick, some wholly, some 

 half, others not at all, cracked. Schimper is 

 lost in the great impenetrable world of suns, 

 with their planets, moons, and comets ; he 

 soars even into the region of the double stars, 

 the milky way, and the nebulae. 



On a loose sheet come the " nuts to pick." 

 It contains a long list of mooted questions, a 

 few of which are given here to show the ex- 

 change of thought between Agassiz and his 

 friend, the one propounding zoological, the 

 other botanical, puzzles. Although most of 

 the problems were solved long ago, it is not 

 uninteresting to follow these young minds in 

 their search after the laws of structure and 

 growth, dimly perceived at first, but becoming 

 gradually clearer as they go on. The very 

 first questions hint at the law of Phyllotaxis, 

 then wholly unknown, though now it makes 



