My dear Hooker

Many thanks for your agreeable note.— Please keep the Geograph. M.S. till you hear from me; for I may have to beg you to send it to Murray; as through Lyells intervention I hope he will publish; but he requires first to see M.S.¹

I demur to what you say that we change climate of the world to account for “migration of bugs flies &c”,² we do nothing of sort; for we rest on scored rocks, old moraines, arctic shells & mammifers.— I have no theory whatever about cause of cold, no more than I have for cause of elevation & subsidence; & I can see no reason why I sh^d not use cold, or elevation or subsidence to explain any other phenomena, such as of distribution.— I think if I had space & time, I could make pretty good case against any great continental changes since Glacial epoch, & this has mainly led me to give up the Lyellian doctrine as insufficient to explain all mutations of climate.—

I was amused at the Brit. Mus evidence:³ I am made to give my opinion so authoritatively on botanical matters!

I shall be very glad to see your proof-sheets.— I hope to begin printing in middle of May

As for our belief in origin of species, making any difference in descriptive work, I am sure it is incorrect.—for I did all my Barnacle work under this point of view. Only I often groaned that I was not allowed simply to decide whether a difference was sufficient to deserve a name.⁴

I am glad to hear about Huxley,—a wonderful man.⁵

Ever yours affect in Haste. C. D.