220 AMERICA : GEOGRAPHICAL DISTRIBUTION 



Now for yours of July 15th. I am glad to hear of the 

 Chilian types in West N. America but may retort upon 

 your proverb apropos of Greenland : ' Ponderandum non 

 numerandum, &c.' 



I deny that the Equator is the Grandfather of climate 

 it is the Grandmother the Poles are the Grandfathers ; 

 i.e. it is the alternate heating and cooling of the most extra - 

 tropical areas that ' kicks up the bobbery.' 



Assuredly you should try for an English market for 

 your Introduction to Morphology and classification. It is 

 much wanted but all the world is mad after Physiology 

 and Histology^ and Morphology pure and classifications 

 are despised on the Continent, and Britain is fast following 

 suit. 



To Charles Darwin 



October 4, 1878. 



I am very busy at Gray's and my joint paper on the 

 Botany of Colorado in relation to the rest of America, and 

 the Universe I suppose. It has I find curious relations with 

 Altai which I hope to show are not shared by the Floras of 

 either Eastern or Western America, but these comparisons 

 are very laborious. 



To the Same 



October 7, 1878. 



I am working hard at the Rocky Mountain Flora, and 

 find that it contains many Old World genera and species 

 not found in the equally lofty Sierra Nevada which runs 

 parallel to it for so many hundred miles, and I am excessively 

 interested about it. One would suppose that the migration 

 along the American meridional ridges from the North South- 

 wards and back again was the simplest thing in the world, 

 but it has not been so I am sure. The Rocky Mountain 

 Flora will stand a very fair comparison with the Altai, 

 which the Sierra Nevada will not. 



To Asa Gray 



August 2, 1879. 



What a splendid time you had of it on the Alleghanies. 

 I should indeed like to have been with you both. 



So next year you are normally due in England. Come 



