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LETTER 354. TO J.D. HOOKER. Down, February 25th [1862].

I have almost finished your Arctic paper, and I must tell you how I
admire it. (354/1. "Outlines of the Distribution of Arctic Plants"
[Read June 21st, 1860], "Linn. Soc. Trans." XXIII., 1862, page 251. The
author's remarks on Mr. Darwin's theories of Geographical Distribution
are given at page 255: they are written in a characteristically
generous spirit.) The subject, treated as you have treated it, is really
magnificent. Good Heaven, what labour it must have cost you! And what a
grand prospect there is for the future. I need not say how much pleased
I am at your notice of my work; for you know that I regard your opinion
more than that of all others. Such papers are the real engine to compel
people to reflect on modification of species; any one with an enquiring
mind could hardly fail to wish to consider the whole subject after
reading your paper. By Jove! you will be driven, nolens volens, to a
cooled globe. Think of your own case of Abyssinia and Fernando Po, and
South Africa, and of your Lebanon case (354/2. See "Origin," Edition
VI., page 337.); grant that there are highlands to favour migration, but
surely the lowlands must have been somewhat cooled. What a splendid new
and original evidence and case is that of Greenland: I cannot see how,
even by granting bridges of continuous land, one can understand the
existing flora. I should think from the state of Scotland and America,
and from isothermals, that during the coldest part of Glacial period,
Greenland must have been quite depopulated. Like a dog to his vomit, I
cannot help going back and leaning to accidental means of transport
by ice and currents. How curious also is the case of Iceland. What a
splendid paper you have made of the subject. When we meet I must ask you
how much you attribute richness of flora of Lapland to mere climate; it
seems to me very marvellous that this point should have been a sort of
focus of radiation; if, however, it is unnaturally rich, i.e. contains
more species than it ought to do for its latitude, in comparison with
the other Arctic regions, would it not thus falsely seem a focus of
radiation? But I shall hereafter have to go over and over again your
paper; at present I am quite muddy on the subject. How very odd, on any
view, the relation of Greenland to the mountains of E. N. America; this
looks as if there had been wholesale extinction in E. N. America. But I
must n