My dear Hooker

I am heartily glad to hear that my Lyellian notes have been of slightest use to you;² I do not think the view is exaggerated. I am also very glad to hear about M^r R. How kind you have been about it.—³

Your letter & lists have most deeply interested me.⁴ First for less important point, about hermaphrodite trees. It is enough to knock me down, yet I can hardly think that Britain, N. America & N. Zealand should all have been theoretically right by chance.⁵ Have you at Kew any Eucalyptus or Australian mimosa, which sets its seeds; if so would it be very troublesome to observe when pollen is mature, & whether the pollen-tube, enters stigma readily immediately that pollen is mature or some little time afterwards; though if pollen is not mature for some little time after flower opens, the stigma might be ready first, though according to C. C. Sprengel this is a rarer case.⁶ I wrote to Müller for chance of his being able & willing to observe this.—⁷

Your fact of greater number of European plants N.B. But do you mean greater percentage??⁸ in S. Australia than in S. America is astounding & very unpleasant to me; for from N. W. America (where nearly same flora exists as in Canada?) to T. del Fuego, there is far more continuous high-land than from Europe to Tasmania. There must have, I sh^d. think, existed some curious barrier on American High-Road; dryness of Peru; excessive damp of Panama, or some other confounded cause which either prevented immigration or has since destroyed them.— You say I may ask questions, & so I have on enclosed paper. but it will of course be a very different thing whether you will think them worth labour of answering.⁹

May I keep the lists now returned; otherwise I will have them copied?—

You said that you could give me a few cases of Australian forms & identical species going N. by Malay Archipelago-mountains to Philippines & Japan; but if these are given in your Introduction this will suffice for me.—¹⁰

Your lists seem to me wonderfully interesting.

According to my theoretical notions, I am not satisfied with what you say about local plants in S.W. corner of Australia & the seeds not readily germinating: do be cautious on this;—consider lapse of time.¹¹ It does not suit my stomach at all.— It is like Wollaston’s confined Land-snails in Porto Santo & confined to same spots since a tertiary period, being due to their slow crawling powers; & yet we know that other snail-shells have stocked a whole country, within a very few years with same breeding powers, & same crawling powers, when the conditions have been favourable to the life of the introduced species.—¹²

Hypothetically I should rather look at the case as owing to,—but as my notions are not very simple or clear & only hypothetical they are not worth inflicting on you.—

I had vowed not to mention my everlasting Abstract to you again, for I am sure I have bothered you far more than enough about it; but as you allude to its previous publication, I may say that I have chapters on Instinct & Hybridism to abstract, which may take a fortnight each; & my materials for Palæontology, Geograp. Distrib. & Affinities, being less worked up, I daresay each of these will take me 3 weeks, so that I shall not have done at soonest till April, & then my Abstract will in bulk make a small volume.¹³ I never give more than one or two instances & I pass over briefly all difficulties & yet I cannot make my abstract shorter, to be satisfactory, than I am now doing & yet it will expand to small volume.—

I have for some time thought that I have done you an ill-service, in return for the immense good, which I have reaped from you, in discussing all my notions with you; & now there is no doubt of it, as you would have arrived at the frigorific mixture independently.¹⁴ My only comfort is, that without you were prepared to give up species, you must have been greatly bothered in your conclusions, for the ranges of identical & representative species are so mixed up in this case, as hardly to be separated. And I can most truly say that I never thought that I might be interfering with your independent work. Oh that I had but health to get my everlasting work done.—

Ever yours C. Darwin

In about a months time I shall begin & have my first part of M.S. fairly copied, would it be of any use to you to read it in M.S. & refer to it if wanted, before it is printed. I should hate doing this ie reading M.S. myself, but there is no harm in offering it.—¹⁵