To J. D. Hooker 24 December 1
Down Bromley Kent
My dear Hooker
Your news about you unsollicited Salary & House is jolly & creditable to the government.— My room (28 x 19) with divided room above with all fixtures (& painted) not furniture & plaistered outside cost about £500.—2 I am heartily glad of this news.—
Your facts about distribution are indeed very striking. I remember well that none of your many wonderful facts in your several works perplexed me for years more than the migration having been mainly from N. to S & not in the reverse direction. I have now at last satisfied myself (but that is very different from satisfying others) on this head; but it wd. take a little volume to fully explain myself.—3 I did not for long see the bearing of a conclusion, at which I had arrived, with respect to this subject. It is that species inhabiting a very large area, & therefore existing in large numbers & which have been subjected to the severest competition with many other forms, will have arrived through natural selection, at a higher stage of perfection than the inhabitants of a small area.— Thus I explain the fact of so many anomalous or what may be called “living fossils” inhabiting now only fresh-water, having been beaten out & exterminated in the sea by more improved forms; thus all existing Ganoid fishes are fresh-water as is Lepidosiren & Ornithorhynchus &c.— The plants of Europe with Asia as being largest territory I look at as the most “improved”, & therefore as being able to withstand the less perfected Australian plants; though these could not resist the Indian.— See how all the productions of N. Zealand yield to those of Europe.—
I daresay you will think all is utter bosh; but I believe it to be solid truth!4 You will, I think, admit that Australian plants flourishing so in India is no argument that they could hold their own against the ten thousand natural contingencies of other plants, insects, animals &c &c.— With respect to S.W Australia & the Cape, I am shut up, & can only d—n the whole case.—5
I do not see that your Indian migration & the Glacial need have any con-nection; I shd think (??) the Indian prior during a pliocene age, when from evidence from Mammals, no doubt there was continuous land connecting Malay Sumatra, Java, Borneo as far probably as Timor or even further, but not actually continuous with Australia. Perhaps land remained continuous to Glacial epoch; if so Mammals become changed quickly?? You say you shd like to see my M.S. but you did read & approved of my long Glacial chapter, & I have not yet written my abstract on whole geographical Distribution, nor shall begin it for 2 or 3 weeks. But either abstract or the old M.S, I shd be delighted to send you especially the Abstract chapter But I have not in the old M.S. discussed migration from N. to S. & not reversely.6
I cannot answer about Australia palæozoic plants; I have seen long lists of coal plants, but I shd quite doubt the identifications: I believe that there are wide geological gaps in Australia. Nor can I answer about Chobham sands: I cannot remember what precise stage they occupy in lower Eocenes; I had not heard of Banksian wood, how very curious!!
When you write next please tell me, whether I understand in your list rightly, that all the Fuegian plants which are common to Europe are likewise common to N. America; for years I have been curious to know this.7 Also can you guess, what plant Audubon means by “our great Water Lily in the Southern U. States” & what sized seeds it has? He found its seeds in stomach of Heron. [reverse question mark] from digested Fish.?-?.?-?.8
I have now written 330 folio pages of my abstract & it will require another 150–200; so that it will make a printed volume of 400 pages, & must be printed
separately, which I think will be better in many respects. The subject really seems to me too large for discussion at any Society, & I believe Religion would be brought in by men, whom I know.—
I am thinking of a 12mo volume, like Lyells 4th or 5th Edition of Principles.—9
I have had nice friendly note from A. Gray: he approves of my crossing notions in regard to Leguminosæ.10 Did you think that my facts upheld my notions?—
I have written you a scandalously long note. So good Bye | My dear Hooker | Ever yours | C. Darwin
I was so sorry not to meet you at Phil. Club.—11
The connection of Floras of Timor & Mauritius, according to Decaisne, has always struck me as particularly perplexing.12 I often look at Maldiva atolls & fancy a long chain of islands. Your connexion of India & N. Australia seems to bear on this.—
P.S. I have found my little Review of Waterhouse in Annals of Nat. Hist. Vol. 19 1847 p. 53.13 I have never till just now looked at it since I wrote it. I doubt whether it is worth your glancing at,—S. Australia seems to have very little peculiar.— I have no idea when Jukes wrote on subject. I am surprised that I did not quote him, for I now remember having read something on subject.— But perhaps I wrote before he did.—14
what an important datum, it would be if one knew average comparative rate of specific change in Mammals & plants.—
Wide-ranging species more "improved" than relics in small areas because they exist in large numbers and thus are subject to intense competition.
His abstract is 330 folio pages long so far.