Are you aware that Mr. W. Earl (Probably Mr. W. Earle's paper, Geographical Soc. Journal, 1845.) published several years ago the view of distribution of animals in the Malay Archipelago, in relation to the depth of the sea between the islands? I was much struck with this, and have been in the habit of noting all facts in distribution in that archipelago, and elsewhere, in this relation. I have been led to conclude that there has been a good deal of naturalisation in the different Malay islands, and which I have thought, to a certain extent, would account for anomalies. Timor has been my greatest puzzle. What do you say to the peculiar Felis there? I wish that you had visited Timor; it has been asserted that a fossil mastodon's or elephant's tooth (I forget which) has been found there, which would be a grand fact. I was aware that Celebes was very peculiar; but the relation to Africa is quite new to me, and marvellous, and almost passes belief. It is as anomalous as the relation of PLANTS in S.W. Australia to the Cape of Good Hope. I differ WHOLLY from you on the colonisation of oceanic islands, but you will have EVERY ONE else on your side. I quite agree with respect to all islands not situated far in the ocean. I quite agree on the little occasional intermigration between lands [islands?] when once pretty well stocked with inhabitants, but think this does not apply to rising and ill- stocked islands. Are you aware that ANNUALLY birds are blown to Madeira, the Azores (and to Bermuda from America). I wish I had given a fuller abstract of my reasons for not believing in Forbes' great continental extensions; but it is too late, for I will alter nothing--I am worn out, and must have rest. Owen, I do not doubt, will bitterly oppose us...Hooker is publishing a grand introduction to the Flora of Australia, and goes the whole length. I have seen proofs of about half. With every good wish.
Believe me, yours very sincerely, C. DARWIN.
CHARLES DARWIN TO J.D. HOOKER. Down, September 1st [1859].
...I am not surprised at your finding your Introduction very difficult. But do not grudge the labour, and do not say you "have burnt your fingers," and are "deep in the mud"; for I feel sure that the result will be well worth the labour. Unless I am a fool, I must be a judge to some extent of the value of such general essays, and I am fully convinced that yours are the must valuable ever published.
I have corrected all but the last two chapters of my book, and hope to have done revises and all in about three weeks, and then I (or we all) shall start for some months' hydropathy; my health has been very bad, and I am becoming as weak as a child, and incapable of doing anything whatever, except my three hours daily work at proof-sheets. God knows whether I shall ever be good at anything again, perhaps a long rest and hydropathy may do something.
I have not had A. Gray's Essay, and should not feel up to criticise it, even if I had the impertinence and courage. You will believe me that I speak strictly the truth when I say that your Australian Essay is EXTREMELY interesting to me, rather too much so. I enjoy reading it over, and if you think my criticisms are worth anything to you, I beg you to send the sheets (if you can give me time for good days); but unless I can render you any little, however little assistance, I would rather read the essay when published. Pray understand that I should be TRULY vexed not to read them, if you wish it for your own sake.
I had a terribly long fit of sickness yesterday, which makes the world rather extra gloomy to-day, and I have an insanely strong wish to finish my accursed book, such corrections every page has required as I never saw before. It is so weariful, killing the whole afternoon, after 12 o'clock doing nothing whatever. But I will grumble no more. So farewell, we shall meet in the winter I trust.
Farewell, my dear Hooker, your affectionate friend, C. DARWIN.
CHARLES DARWIN TO C. LYELL. Down, September 2nd [1859].