More Letters of Charles Darwin — Volume 1

Is not the similarity of plants of Kerguelen Land and southern S. America very curious? Is there any instance in the northern hemisphere of plants being similar at such great distances? With thanks for your letter and for your having undertaken my small collection of plants,

Believe me, my dear Sir, Yours very truly, C. DARWIN.

Do remember my prayer, and write as well for botanical ignoramuses as for great botanists. There is a paper of Carmichael (313/3. "Some Account of the Island of Tristan da Cunha and of its Natural Productions." — "Linn. Soc. Trans." XII., 1818, page 483.) on Tristan d'Acunha, which from the want of general remarks and comparison, I found {torn out} to me a dead letter. — I presume you will include this island in your views of the southern hemisphere.

P.S. — I have been looking at my poor miserable attempt at botanical-landscape-remarks, and I see that I state that the species of beech which is least common in T. del Fuego is common in the forest of Central Chiloe. But I will enclose for you this one page of my rough journal.

LETTER 314. TO J.D. HOOKER. Down, March 31st (1844).

I have been a shameful time in returning your documents, but I have been very busy scientifically, and unscientifically in planting. I have been exceedingly interested in the details about the Galapagos Islands. I need not say that I collected blindly, and did not attempt to make complete series, but just took everything in flower blindly. The flora of the summits and bases of the islands appear wholly different; it may aid you in observing whether the different islands have representative species filling the same places in the economy of nature, to know that I collected plants from the lower and dry region in all the islands, i.e., in the Chatham, Charles, James, and Albemarle (the least on the latter); and that I was able to ascend into the high and damp region only in James and Charles Islands; and in the former I think I got every plant then in flower. Please bear this in mind in comparing the representative species. (You know that Henslow has described a new Opuntia from the Galapagos.) Your observations on the distribution of large mundane genera have interested me much; but that was not the precise point which I was curious to ascertain; it has no necessary relation to size of genus (though perhaps your statements will show that it has). It was merely this: suppose a genus with ten or more species, inhabiting the ten main botanical regions, should you expect that all or most of these ten species would have wide ranges (i.e. were found in most parts) in their respective countries? (314/1. This point is discussed in a letter in "Life and Letters," Volume II., page 25, but not, we think in the "Origin"; for letters on large genera containing many varieties see "Life and Letters," Volume II., pages 102-7, also in the "Origin," Edition I., page 53, Edition VI., page 44. In a letter of April 5th, 1844, Sir J.D. Hooker gave his opinion: "On the whole I believe that many individual representative species of large genera have wide ranges, but I do not consider the fact as one of great value, because the proportion of such species having a wide range is not large compared with other representative species of the same genus whose limits are confined."

It may be noted that in large genera the species often have small ranges ("Origin," Edition VI., page 45), and large genera are more commonly wide-ranging than the reverse.) To give an example, the genus Felis is found in every country except Australia, and the individual species generally range over thousands of miles in their respective countries; on the other hand, no genus of monkey ranges over so large a part of the world, and the individual species in their respective countries seldom range over wide spaces. I suspect (but am not sure) that in the genus Mus (the most mundane genus of all mammifers) the individual species have not wide ranges, which is opposed to my query.

I fancy, from a paper by Don, that some genera of grasses (i.e. Juncus or Juncaceae) are widely diffused over the world, and certainly many of their species have very wide ranges — in short, it seems that my question is whether there is any relation between the ranges of genera and of individual species, without any relation to the size of the genera. It is evident a genus might be widely diffused in two ways: 1st, by many different species, each with restricted ranges; and 2nd, by many or few species with wide ranges. Any light which you could throw on this I should be very much obliged for. Thank you most kindly, also, for your offer in a former letter to consider any other points; and at some future day I shall be most grateful for a little assistance, but I will not be unmerciful.

Swainson has remarked (and Westwood contradicted) that typical genera have wide ranges: Waterhouse (without knowing these previous remarkers) made to me the same observation: I feel a laudable doubt and disinclination to believe any statement of Swainson; but now Waterhouse remarks it, I am curious on the point. There is, however, so much vague in the meaning of "typical forms," and no little ambiguity in the mere assertion of "wide ranges" (for zoologists seldom go into strict and disagreeable arithmetic, like you botanists so wisely do) that I feel very doubtful, though some considerations tempt me to believe in this remark. Here again, if you can throw any light, I shall be much obliged. After your kind remarks I will not apologise for boring you with my vague queries and remarks.

LETTER 315. TO J.D. HOOKER. Down, December 25th {1844}. Happy Christmas to you.

(315/1. The following letter refers to notes by Sir J.D. Hooker which we have not seen. Though we are therefore unable to make clear many points referred to, the letter seems to us on the whole so interesting that it is printed with the omission of only one unimportant sentence.

The subjects dealt with in the letter are those which were occupying Hooker's attention in relation to his "Flora Antarctica" (1844).)

I must thank you once again for all your documents, which have interested me very greatly and 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 MS.; 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 should like to see the results worked out, and then you can judge, whether this be advisable for the botanical world.

Looking at the globe, the Auckland and Campbell I., New Zealand, and Van Diemen's Land so evidently are geographically related, that I should wish, before any comparison was made with far more distant countries, to understand their floras, in relation to each other; and the southern ones to the northern temperate hemisphere, which I presume is to every one an almost involuntary standard of comparison. To understand the relation of the floras of these islands, I should like to see the group divided into a northern and southern half, and to know how many species exist in the latter —

1. Belonging to genera confined to Australia, Van Diemen's Land and north New Zealand.

2. Belonging to genera found only on the mountains of Australia, Van Diemen's Land, and north New Zealand.

3. Belonging to genera of distribution in many parts of the world (i.e., which tell no particular story).

4. Belonging to genera found in the northern hemisphere and not in the tropics; or only on mountains in the tropics.

I daresay all this (as far as present materials serve) could be extracted from your tables, as they stand; but to any one not familiar with the names of plants, this would 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 Arctic floras.

If the Fuegian flora was treated in the analogous way (and this would incidentally show how far the Cordillera are a high-road of genera), I should then be prepared far more easily and satisfactorily to understand the relations of Fuegia with the Auckland Islands, and consequently with the mountains of Van Diemen's Land. Moreover, the marvellous facts of their intimate botanical relation (between Fuegia and the Auckland Islands, etc.) would stand out more prominently, after the Auckland Islands had been first treated of under the purely geographical relation of position. A triple division such as yours would lead me to suppose that the three places were somewhat equally distant, and not so greatly different in size: the relation of Van Diemen's Land seems so comparatively small, and 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...

I think a list of the genera, common to Fuegia on the one hand and on the other to Campbell, etc., and to the mountains of Van Diemen's Land or New Zealand (but not found in the lowland temperate, and southern tropical parts of South America and Australia, or New Zealand), would prominently bring out, at the same time, the relation between these Antarctic points one with another, and with the northern or Arctic regions.

In Article III. is it meant to be expressed, or might it not be understood by this article, that the similarity of the distant points in the 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 and Australia, etc., being "materially approximated," and this closer proximity being correlative with a greater similarity of their plants: I find on the globe, that Van Diemen's Land and Fuegia are only about one-fifth nearer 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. Down, March 19th {1845}.

...I was very glad to hear Humboldt's views on migrations and double creations. It is very presumptuous, but I feel sure that though one cannot prove extensive migration, the leading considerations, proper to the subject, are omitted, and I will venture to say even by Humboldt. I should like some time to put the case, like a lawyer, for your consideration, in the point of view under which, I think, it ought to be viewed. The conclusion which I come to is, that we cannot pretend, with our present knowledge, to put any limit to the possible, and even probable, migration of plants. If you can show that many of the Fuegian plants, common to Europe, are found in intermediate points, it will be a grand argument in favour of the actuality of migration; but not finding them will not, in my eyes, much diminish the probability of their having thus migrated. My pen always runs away, in writing to you; and a most unsteady, vilely bad pace it goes. What would I not give to write simple English, without having to rewrite and rewrite every sentence.

LETTER 317. TO J.D. HOOKER. Friday {June 29th, 1845}.

I have been an ungrateful dog for not having answered your letter sooner, but I have been so hard at work correcting proofs (317/1. The second edition of the "Journal."), together with some unwellness, that I have not had one quarter of an hour to spare. I finally corrected the first third of the old volume, which will appear on July 1st. I hope and think I have somewhat improved it. Very many thanks for your remarks; some of them came too late to make me put some of my remarks more cautiously. I feel, however, still inclined to abide by my evaporation notion to account for the clouds of steam, which rise from the wooded valleys after rain. Again, I am so obstinate that I should require very good evidence to make me believe that there are two species of Polyborus (317/2. Polyborus Novae Zelandiae, a carrion hawk mentioned as very common in the Falklands.) in the Falkland Islands. Do the Gauchos there admit it? Much as I talked to them, they never alluded to such a fact. In the Zoology I have discussed the sexual and immature plumage, which differ much.

I return the enclosed agreeable letter with many thanks. I am extremely glad of the plants collected at St. Paul's, and shall be particularly curious whenever they arrive to hear what they are. I dined the other day at Sir J. Lubbock's, and met R. Brown, and we had much laudatory talk about you. He spoke very nicely about your motives in now going to Edinburgh. He did not seem to know, and was much surprised at what I stated (I believe correctly) on the close relation between the Kerguelen and T. del Fuego floras. Forbes is doing apparently very good work about the introduction and distribution of plants. He has forestalled me in what I had hoped would have been an interesting discussion — viz., on the relation between the present alpine and Arctic floras, with connection to the last change of climate from Arctic to temperate, when the then Arctic lowland plants must have been driven up the mountains. (317/3. Forbes' Essay "On the Connection between the Distribution of the Existing Fauna and Flora of the British Isles and the Geological Changes which have affected their Area," was published in 1846. See note, Letter 20.)

I am much pleased to hear of the pleasant reception you received at Edinburgh. (317/4. Sir J.D. Hooker was a candidate for the Chair of Botany at Edinburgh. See "Life and Letters," I., pages 335, 342.) I hope your impressions will continue agreeable; my associations with auld Reekie are very friendly. Do you ever see Dr. Coldstream? If you do, would you give him my kind remembrances? You ask about amber. I believe all the species are extinct (i.e. without the amber has been doctored), and certainly the greater number are. (317/5. For an account of plants in amber see Goeppert and Berendt, "Der Bernstein und die in ihm befindlichen Pflanzenreste der Vorwelt," Berlin, 1845; Goeppert, "Coniferen des Bernstein," Danzig, 1883; Conwentz, "Monographie der Baltischen Bernsteinbaume," Danzig, 1890.)

If you have any other corrections ready, will you send them soon, for I shall go to press with second Part in less than a week. I have been so busy that I have not yet begun d'Urville, and have read only first chapter of Canary Islands! I am most particularly obliged to you for having lent me the latter, for I know not where else I could have ever borrowed it. There is the "Kosmos" to read, and Lyell's "Travels in North America." It is awful to think of how much there is to read. What makes H. Watson a renegade? I had a talk with Captain Beaufort the other day, and he charged me to keep a book and enter anything which occurred to me, which deserved examination or collection in any part of the world, and he would sooner or later get it in the instructions to some ship. If anything occurs to you let me hear, for in the course of a month or two I must write out something. I mean to urge collections of all kinds on any isolated islands. I suspect that there are several in the northern half of the Pacific, which have never been visited by a collector. This is a dull, untidy letter. Farewell.

As you care so much for insular floras, are you aware that I collected all in flower on the Abrolhos Islands? but they are very near the coast of Brazil. Nevertheless, I think they ought to be just looked at, under a geographical point of view.

LETTER 318. TO J.D. HOOKER. Down, November {1845}.

I have just got as far as Lycopodium in your Flora, and, in truth, cannot say enough how much I have been interested in all your scattered remarks. I am delighted to have in print many of the statements which you made in your letters to me, when we were discussing some of the geographical points. I can never cease marvelling at the similarity of the Antarctic floras: it is wonderful. I hope you will tabulate all your results, and put prominently what you allude to (and what is pre-eminently wanted by non-botanists like myself), which of the genera are, and which not, found in the lowland or in the highland Tropics, as far as known. Out of the very many new observations to me, nothing has surprised me more than the absence of Alpine floras in the S{outh} Islands. (318/1. See "Flora Antarctica," I., page 79, where the author says that "in the South...on ascending the mountains, few or no new forms occur." With regard to the Sandwich Islands, Sir Joseph wrote (page 75) that "though the volcanic islands of the Sandwich group attain a greater elevation than this {10,000 feet}, there is no such development of new species at the upper level." More recent statements to the same effect occur in Grisebach, "Vegetation der Erde," Volume II., page 530. See also Wallace, "Island Life," page 307.) It strikes me as most inexplicable. Do you feel sure about the similar absence in the Sandwich group? Is it not opposed quite to the case of Teneriffe and Madeira, and Mediterranean Islands? I had fancied that T. del Fuego had possessed a large alpine flora! I should much like to know whether the climate of north New Zealand is much more insular than Tasmania. I should doubt it from general appearance of places, and yet I presume the flora of the former is far more scanty than of Tasmania. Do tell me what you think on this point. I have also been particularly interested by all your remarks on variation, affinities, etc.: in short, your book has been to me a most valuable one, and I must have purchased it had you not most kindly given it, and so rendered it even far more valuable to me. When you compare a species to another, you sometimes do not mention the station of the latter (it being, I presume, well-known), but to non-botanists such words of explanation would add greatly to the interest — not that non-botanists have any claim at all for such explanations in professedly botanical works. There is one expression which you botanists often use (though, I think, not you individually often), which puts me in a passion — viz., calling polleniferous flowers "sterile," as non-seed-bearing. (318/2. See Letter 16.) Are the plates from your own drawings? They strike me as excellent. So now you have had my presumptuous commendations on your great work.

LETTER 319. TO J.D. HOOKER. Down, Friday {1845-6}.

It is quite curious how our opinions agree about Forbes' views. (319/1. See Letter 20.) I was very glad to have your last letter, which was even more valuable to me than most of yours are, and that is saying, I assure you, a great deal. I had written to Forbes to object about the Azores (319/2. Edward Forbes supposed that the Azores, the Madeiras, and Canaries "are the last remaining fragments" of a continent which once connected them with Western Europe and Northern Spain. Lyell's "Principles," Edition XI., Volume II., page 410. See Forbes, op. cit.) on the same grounds as you had, and he made some answer, which partially satisfied me, but really I am so stupid I cannot remember it. He insisted strongly on the fewness of the species absolutely peculiar to the Azores — most of the non-European species being common to Madeira. I had thought that a good sprinkling were absolutely peculiar. Till I saw him last Wednesday I thought he had not a leg to stand on in his geology about his post-Miocene land; and his reasons, upon reflection, seem rather weak: the main one is that there are no deposits (more recent than the Miocene age) on the Miocene strata of Malta, etc., but I feel pretty sure that this cannot be trusted as evidence that Malta must have been above water during all the post-Miocene period. He had one other reason, to my mind still less trustworthy. I had also written to Forbes, before your letter, objecting to the Sargassum (319/3. Edward Forbes supposed that the Sargassum or Gulf-weed represents the littoral sea-weeds of a now submerged continent. "Mem. Geol. Survey Great Britain," Volume I., 1846, page 349. See Lyell's "Principles," II., page 396, Edition XI.), but apparently on wrong grounds, for I could see no reason, on the common view of absolute creations, why one Fucus should not have been created for the ocean, as well as several Confervae for the same end. It is really a pity that Forbes is quite so speculative: he will injure his reputation, anyhow, on the Continent; and thus will do less good. I find this is the opinion of Falconer, who was with us on Sunday, and was extremely agreeable. It is wonderful how much heterogeneous information he has about all sorts of things. I the more regret Forbes cannot more satisfactorily prove his views, as I heartily wish they were established, and to a limited extent I fully believe they are true; but his boldness is astounding. Do I understand your letter right, that West Africa (319/4. This is of course a misunderstanding.) and Java belong to the same botanical region — i.e., that they have many non-littoral species in common? If so, it is a sickening fact: think of the distance with the Indian Ocean interposed! Do some time answer me this. With respect to polymorphism, which you have been so very kind as to give me so much information on, I am quite convinced it must be given up in the sense you have discussed it in; but from such cases as the Galapagos birds and from hypothetical notions on variation, I should be very glad to know whether it must be given up in a slightly different point of view; that is, whether the peculiar insular species are generally well and strongly distinguishable from the species on the nearest continent (when there is a continent near); the Galapagos, Canary Islands, and Madeira ought to answer this. I should have hypothetically expected that a good many species would have been fine ones, like some of the Galapagos birds, and still more so on the different islands of such groups.