To J. D. Hooker 25 December 
Down Bromley Kent
Dec. 25th Happy Christmas to you—
My dear Hooker
I must thank you once again for all your documents which have me interested me very greatly & surprised me. I found it very difficult to charge my head with all your tabulated results, but this I perfectly well know is in main part due to that head not being a Botanical one, aided by the tables being in M.S.1 I think, however, to an ignoramus, they might be made clearer; but pray mind, that this is very different from saying that I think Botanists ought to arrange their highest results for non-botanists to understand easily. I will tell you, how for my individual self, I shd like to see the results worked out, & then you can judge, whether this be adviseable for the Botanical world.
Looking at the Globe, the Auckland, Campbell I, New Zealand & Van Diemens so evidently are geographically related, that I shd wish, before any comparison was made with far more distant countries, to understand their floras, in relation to each other; & the southern ones to the northern temperate hemisphere, which I presume is to everyone an almost involuntary standard of Comparison. To understand the relations of the Floras of these islands, I shd like to see the group divided into a northern & southern half, & to know how many species exist in the latter 1 belonging to genera confined to Australia Van Diemens land & North New Zealand 2 ——— found only on the mountains of do. (⸮) — 3. ——— of distribution in many parts of the world. (ie. which tell no particular story.) 4. ——— found in the northern hemisphere & not in the Tropics; or only on mountains in the Tropics
I daresay all this (as far as present materials serve) cd be extracted from your tables, as they stand; but to anyone not familiar with the names of plants, this wd be difficult. I felt particularly the want of not knowing, which of the genera are found in the lowland Tropics, in understanding the relation of the antarctic with the artic Floras.
If the Fuegian Flora was treated in the analogous way, (& this would incidentally show how far the Cordillera are a high-road of genera.) I shd then be prepared far more easily & satisfactorily to understand the relations of Fuegia with the Auckland Isd &c; & consequently with the mountains of Van Diemens Land. Moreover, the marvellous fact of their intimate Botanical relation between Fuegia & the Auckland Isd &c would stand out more prominently, after the Auckland Isd had been first treated of under the purely geographical relation of position. A triple division such as yours, wd lead me to suppose that the three places were somewhat equally distant, & not so greatly different in size: the relation of Van Diemen’s land seems so comparatively small, & that relation being in its alpine plants, makes me feel that it ought only to be treated of as a subdivision of the large group, including Auckland, Campbell, New Zealand.
In Art VII—does the expression “more remarkable genera” (& sub-sections of genera) mean those confined to the stated countries?— Art VI does not appear to me clear, though I now understand it.
I think a list of the genera, common to Fuegia, on the one hand & on the other to Campbell &c & to the mountains of Van Diemens Land or New Zealand, (but not found in the lowland temperate, & S. tropical parts of S. America & Australia, or New Zealand), would prominently bring out, at the same time, the relation between these antarctic points one with another, & with the northern or arctic regions.
In Art III. Is it meant to be expressed, or might it not be understood by this article, that the similarity of the distant points in antarctic regions was as close as between distant points in the Arctic regions? I gather this is not so.— You speak of the southern points of America & Australia &c being “materially approximated” & this closer proximity being corelative with a greater similarity of their plants: I find on the globe, that Van Diemen’s Land & Fuegia are only about nearer than the whole distance between Port Jackson & Concepcion in chile;—and again that Campbell Isld & Fuegia are only nearer than the East point of North N. Zealand & Concepcion: now do you think in such immense distances both over open oceans, that one fifth, less distance say 4000 thousand miles, instead of 5000, can explain or throw much light on a material difference in the degree of similarity in the Floras of the two regions.—
I trust you will work out the New Zealand Flora, as you have commenced at end of letter: is it not quite an original plan?— & is it not very surprising that N. Zealand, so much nearer to Australia than to S. America, shd have an intermediate flora; I had fancied that nearly all the species there, were peculiar to it.— I cannot but think you make one gratuitous difficulty in ascertaining whether New Zealand ought to be classed by itself, or with Australia or S. America,—namely when you seem (bottom of p. 7. of your letter) to say that genera in common, indicate only that the external circumstances for their life are suitable & similar. Surely can not an overwhelming mass of facts be brought against such a proposition: distant parts of Australia possess quite distinct species of Marsupials, but surely this fact of their having the same marsupial genera, is the strongest tie & plainest mark of an original, (so called) creative affinity over the whole of Australia; no one, now, will (or ought) to say that the different parts of Australia have something in the external conditions in common, causing them to be preeminently suitable to Marsupials; & so on in a thousand instances. Though each species, & consequently genus, must be adapted to its country, surely adaptation is manifestly not the governing law in geographical distribution.— Is this not so? & if I understand you rightly, you lessen your own means of comparison by attributing the presence of the same genera to similarity of conditions.
You will groan over my very full compliance with your request to write all I could on your tables, & I have done it with a vengeance: I can hardly say how valuable I must think your results will be, when worked out, as far as the present knowledge & collections serve.
Now for some miscellaneous remarks on your letter: thanks for the offer to let me see specimens of boulders from Cockburn island; but I care only for boulders, as an indication of former climate:2 perhaps Ross will give some information: I hope you will write to N. Zealand on this subject. I see that there are cases in Van Diemen Land, which ought to be explored.—3 Lieut: Britton speaks of a Fern above the coal of V. Diemen’s Land, as being allied to recent Ferns of Tasmania:4 did you collect any of the Coal-Plants there; I shd like to know something about them. Many thanks for your message to Dieffenbach.
I shall have done with the lent Books in about a week or 10 days & will return them by Deliverance company. They have interested me much, & I have ordered two of the numbers of the Journ of Bot, so that I shall return the new uncut copies. I was also very glad to see Silliman, as one or two Papers bore on my present geological writing. Thank you kindly for your offer of letting me see Silliman regularly; but I will not accept it; as I prefer reading each Journal in volumes, bound. I called on Bailliere5 & he tells me the old series of Ann: des Sci. Nat: wd cost 10£, & the new 20£: this is more than I can afford, though I shd much like to have them; so that shd you ever hear of a cheaper set, I shd be greatly obliged if you wd inform me.— It will be extravagant to buy Flinders, without it be very cheap, as, upon reflection, I remember it is so easily borrowed from Public Librarys.—
Watson’s Paper on Azores has surprised me much;6 do you not think it odd, the fewness of peculiar species, & their rarity on the alpine heights: I wish he had tabulated his results: cd you not suggest to him to draw up a paper of such results, comparing these isld with Madeira; surely does not Madeira abound with peculiar forms? A discussion on the relations of the Floras, especially the alpine ones, of Azores, Madeira & Canary Isd would be, I shd think, of general interest:— How curious the several doubtful species, which are referred to by Watson, at the end of his Paper; just as happens with birds at the Galapagos.—7 By the way, I see Pœppig states on the authority of Bertero, that Juan Fernandez has not (ie is not related to) a Chilian Flora, but a South Sea one:8 surely this must be an error.— What a proser Pœppig is!— I have half read through, with pleasure, the Norway tour;9 how pleasantly it is written.
Any time that you can put me in the way of reading about Alpine Flora, I shall feel as the greatest kindness: I grieve there is no better authority for Bourbon, than that stupid Bory: I presume his remark that plants, on isolated Volcanic islds are polymorphous (ie, I suppose, variable?) is quite gratuitous.10
Farewell, my dear Hooker. This letter is infamously unclear, & I fear can be of no use, except giving you the impression of a Botanical ignoramus.— Ever yours | C. Darwin
Questions on JDH’s sketch comparing floras of Australia, New Zealand, and western S. America; wishes to know botanical relations between other southern islands. Botanico-geographical discussions and comments on books sent by JDH.
Please cite as
Darwin Correspondence Project, “Letter no. 803,” accessed on 24 April 2017, http://www.darwinproject.ac.uk/DCP-LETT-803