Darwin-Hooker Letters : Letter from Darwin, C. R. to Hooker, J. D. on 13 June 1850 : 1r
'Darwin, C. R.'
On Himalayan stratigraphy. Believes Hooker's observations of glacial action are the first ever done east of Urals. Barnacles and the species theory; impressed with variation. Effect of Darwin's species sketch on Hooker's view of willow systematics.