ROCKY MOUNTAIN AND ALTAI BOTANY 221 



then ! l I have thought much of my next trip to America, 

 and of my great obstacle, which is Bentham. If I do not 

 go, and he continues as active as now (and I really see no 

 dimming of intellect or cessation of power of work), we 

 really should get on well with Monocots. Except yourself 

 there is no one who can work like him. I have been closely 

 observing all he has been doing with the genera of Coniferae 

 and can only marvel. Now that I am rid of R.S. we see 

 more of one another, and I of his work and he of mine. 

 With the Gen. Plant, on hand I cannot think I ought to 

 leave him. 



We are dreadfully impatient for the continuation of 

 Watson's Bibliography. Nothing short of it will mitigate 

 the curse that hangs over American Botanists. You can 

 have no idea of the labor you cost all hands at the Herbarium 

 when we revise a sheet of Gen. Plant, for checking the 

 references. 



To Charles Darwin 



November 29, 1879. 



We are still thinking over our conjoint work on the 

 Geographical Distribution of American Flora. I have sent 

 him (Asa Gray) a comparison between the Eocky Mt. Flora 

 and that of Altai, which present many curious points of 

 affinity, as in rarity or absence of Oaks, Nuts and other 

 cupulifera which abound all round both areas. He now 

 wants my Lecture to Royal Institution in a modified form, 

 and a comparison of the European and Asiatic Floras, which 

 might be very interesting in reference to America. I have 

 a notion that the E. Asiatic and W. European Temperate 

 and Subtropical Floras are very distinct, but not so distinct 

 as both are from the intermediate Area, and that the Himalaya 

 is the bridge between them, crossing the intermediate area. 



Further the Himalaya contains a mingling of European 

 types with others ' typical of both Eastern and Western 

 America. 



Three years later, at the York meeting of the British 

 Association in 1881, he delivered before the Geographical Sec- 

 tion an address ' On Geographical Distribution/ a survey of 



1 Gray duly came in 1880, and when he left Hooker wrote (October 19, 

 1880) : ' We missed you awfully for a full week, and then put off mourning.' 



