More Letters of Charles Darwin Volume I [227]
than the whole distance between Port Jackson and Concepcion in Chile; and again, that Campbell Island and Fuegia are only one-fifth nearer than the east point of North New Zealand and Concepcion. Now do you think in such immense distances, both over open oceans, that one-fifth less distance, say 4,000 miles instead of 5,000, 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? and is it not very surprising that New Zealand, so much nearer to Australia than South America, should 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 South America--namely, when you seem (bottom of page 7 of your letter) to say that genera in common indicate only that the external circumstances for their life are suitable and similar. (315/2. On December 30th, 1844, Sir J.D. Hooker replied, "Nothing was further from my intention than to have written anything which would lead one to suppose that genera common to two places indicate a similarity in the external circumstances under which they are developed, though I see I have given you excellent grounds for supposing that such were my opinions.") Surely, cannot 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 and 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 their external conditions in common, causing them to be pre- eminently suitable to marsupials; and so on in a thousand instances. Though each species, and consequently genus, must be adapted to its country, surely adaptation is manifestly not the governing law in geographical distribution. Is this not so? and if I understand you rightly, you lessen your own means of comparison--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, and 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 and 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: perhaps Ross will give some information...
Watson's paper on the Azores (315/3. H.C. Watson, "London Journal of Botany," 1843-44.) has surprised me much; do you not think it odd, the fewness of peculiar species, and their rarity on the alpine heights? I wish he had tabulated his results; could you not suggest to him to draw up a paper of such results, comparing these Islands 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, and Canary Islands, would be, I should 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...Any time that you can put me in the way of reading about alpine floras, I shall feel it 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 islands are polymorphous (i.e., I suppose, variable?) is quite gratuitous. Farewell, my dear Hooker. This letter is infamously unclear, and I fear can be of no use, except giving you the impression of a botanical ignoramus.
LETTER 316. TO J.D. HOOKER.
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? and is it not very surprising that New Zealand, so much nearer to Australia than South America, should 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 South America--namely, when you seem (bottom of page 7 of your letter) to say that genera in common indicate only that the external circumstances for their life are suitable and similar. (315/2. On December 30th, 1844, Sir J.D. Hooker replied, "Nothing was further from my intention than to have written anything which would lead one to suppose that genera common to two places indicate a similarity in the external circumstances under which they are developed, though I see I have given you excellent grounds for supposing that such were my opinions.") Surely, cannot 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 and 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 their external conditions in common, causing them to be pre- eminently suitable to marsupials; and so on in a thousand instances. Though each species, and consequently genus, must be adapted to its country, surely adaptation is manifestly not the governing law in geographical distribution. Is this not so? and if I understand you rightly, you lessen your own means of comparison--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, and 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 and 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: perhaps Ross will give some information...
Watson's paper on the Azores (315/3. H.C. Watson, "London Journal of Botany," 1843-44.) has surprised me much; do you not think it odd, the fewness of peculiar species, and their rarity on the alpine heights? I wish he had tabulated his results; could you not suggest to him to draw up a paper of such results, comparing these Islands 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, and Canary Islands, would be, I should 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...Any time that you can put me in the way of reading about alpine floras, I shall feel it 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 islands are polymorphous (i.e., I suppose, variable?) is quite gratuitous. Farewell, my dear Hooker. This letter is infamously unclear, and I fear can be of no use, except giving you the impression of a botanical ignoramus.
LETTER 316. TO J.D. HOOKER.