More Letters of Charles Darwin Volume I Part 24

There is another point on which I have occasionally wished to say a few words. I believe you think with Asa Gray that I have not allowed enough for the stream of variation having been guided by a higher power. I have had lately a good deal of correspondence on this head. Herschel, in his "Physical Geography" (130/2. "Physical Geography of the Globe," by Sir John F.W. Herschel, Edinburgh, 1861. On page 12 Herschel writes of the revelations of Geology pointing to successive submersions and reconstructions of the continents and fresh races of animals and plants.

He refers to a "great law of change" which has not operated either by a gradually progressing variation of species, nor by a sudden and total abolition of one race...The following footnote on page 12 of the "Physical Geography" was added in January, 1861: "This was written previous to the publication of Mr. Darwin's work on the "Origin of Species," a work which, whatever its merit or ingenuity, we cannot, however, consider as having disproved the view taken in the text. We can no more accept the principle of arbitrary and casual variation and natural selection as a sufficient account, per se, of the past and present organic world, than we can receive the Laputan method of composing books (pushed a outrance) as a sufficient one of Shakespeare and the "Principia." Equally in either case an intelligence, guided by a purpose, must be continually in action to bias the directions of the steps of change--to regulate their amount, to limit their divergence, and to continue them in a definite course. We do not believe that Mr.

Darwin means to deny the necessity of such intelligent direction. But it does not, so far as we can see, enter into the formula of this law, and without it we are unable to conceive how far the law can have led to the results. On the other hand, we do not mean to deny that such intelligence may act according to a law (that is to say, on a preconceived and definite plan). Such law, stated in words, would be no other than the actual observed law of organic succession; a one more general, taking that form when applied to our own planet, and including all the links of the chain which have disappeared. BUT THE ONE LAW IS A NECESSARY SUPPLEMENT TO THE OTHER, AND OUGHT, IN ALL LOGICAL PROPRIETY, TO FORM A PART OF ITS ENUNCIATION. Granting this, and with some demur as to the genesis of man, we are far from disposed to repudiate the view taken of this mysterious subject in Mr. Darwin's book." The sentence in italics is no doubt the one referred to in the letter to Lyell. See Letter 243.), has a sentence with respect to the "Origin," something to the effect that the higher law of Providential Arrangement should always be stated. But astronomers do not state that G.o.d directs the course of each comet and planet. The view that each variation has been providentially arranged seems to me to make Natural Selection entirely superfluous, and indeed takes the whole case of the appearance of new species out of the range of science. But what makes me most object to Asa Gray's view is the study of the extreme variability of domestic animals. He who does not suppose that each variation in the pigeon was providentially caused, by acc.u.mulating which variations, man made a Fantail, cannot, I think, logically argue that the tail of the woodp.e.c.k.e.r was formed by variations providentially ordained. It seems to me that variations in the domestic and wild conditions are due to unknown causes, and are without purpose, and in so far accidental; and that they become purposeful only when they are selected by man for his pleasure, or by what we call Natural Selection in the struggle for life, and under changing conditions. I do not wish to say that G.o.d did not foresee everything which would ensue; but here comes very nearly the same sort of wretched imbroglio as between freewill and preordained necessity. I doubt whether I have made what I think clear; but certainly A. Gray's notion of the courses of variation having been led like a stream of water by gravity, seems to me to smash the whole affair. It reminds me of a Spaniard whom I told I was trying to make out how the Cordillera was formed; and he answered me that it was useless, for "G.o.d made them." It may be said that G.o.d foresaw how they would be made.

I wonder whether Herschel would say that you ought always to give the higher providential law, and declare that G.o.d had ordered all certain changes of level, that certain mountains should arise. I must think that such views of Asa Gray and Herschel merely show that the subject in their minds is in Comte's theological stage of science...

Of course I do not want any answer to my quasi-theological discussion, but only for you to think of my notions, if you understand them.

I hope to Heaven your long and great labours on your new edition are drawing to a close.

LETTER 131. TO C. LYELL. Torquay, [August 13th, 1861].

Very many thanks for the orchids, which have proved extremely useful to me in two ways I did not antic.i.p.ate, but were too monstrous (yet of some use) for my special purpose.

When you come to "Deification" (131/1. See Letter 105, note.), ask yourself honestly whether what you are thinking applies to the endless variations of domestic productions, which man acc.u.mulates for his mere fancy or use. No doubt these are all caused by some unknown law, but I cannot believe they were ordained for any purpose, and if not so ordained under domesticity, I can see no reason to believe that they were ordained in a state of nature. Of course it may be said, when you kick a stone, or a leaf falls from a tree, that it was ordained, before the foundations of the world were laid, exactly where that stone or leaf should lie. In this sense the subject has no interest for me.

Once again, many thanks for the orchids; you must let me repay you what you paid the collector.

LETTER 132. TO C. LYELL.

(132/1. The first paragraph probably refers to the proof-sheets of Lyell's "Antiquity of Man," but the pa.s.sage referred to seems not to occur in the book.)

Torquay, August 21st [1861].

...I have really no criticism, except a trifling one in pencil near the end, which I have inserted on account of dominant and important species generally varying most. You speak of "their views" rather as if you were a thousand miles away from such wretches, but your concluding paragraph shows that you are one of the wretches.

I am pleased that you approve of Hutton's review. (132/2. "Some Remarks on Mr. Darwin's Theory," by F.W. Hutton. "Geologist," Volume IV., page 132 (1861). See Letter 124.) It seemed to me to take a more philosophical view of the manner of judging the question than any other review. The sentence you quote from it seems very true, but I do not agree with the theological conclusion. I think he quotes from Asa Gray, certainly not from me; but I have neither A. Gray nor "Origin" with me.

Indeed, I have over and over again said in the "Origin" that Natural Selection does nothing without variability; I have given a whole chapter on laws, and used the strongest language how ignorant we are on these laws. But I agree that I have somehow (Hooker says it is owing to my t.i.tle) not made the great and manifest importance of previous variability plain enough. Breeders constantly speak of Selection as the one great means of improvement; but of course they imply individual differences, and this I should have thought would have been obvious to all in Natural Selection; but it has not been so.

I have just said that I cannot agree with "which variations are the effects of an unknown law, ordained and guided without doubt by an intelligent cause on a preconceived and definite plan." Will you honestly tell me (and I should be really much obliged) whether you believe that the shape of my nose (eheu!) was ordained and "guided by an intelligent cause?" (132/3. It should be remembered that the shape of his nose nearly determined Fitz-Roy to reject Darwin as naturalist to H.M.S. "Beagle" ("Life and Letters," I., page 60).) By the selection of a.n.a.logous and less differences fanciers make almost generic differences in their pigeons; and can you see any good reason why the Natural Selection of a.n.a.logous individual differences should not make new species? If you say that G.o.d ordained that at some time and place a dozen slight variations should arise, and that one of them alone should be preserved in the struggle for life and the other eleven should perish in the first or few first generations, then the saying seems to me mere verbiage. It comes to merely saying that everything that is, is ordained.

Let me add another sentence. Why should you or I speak of variation as having been ordained and guided, more than does an astronomer, in discussing the fall of a meteoric stone? He would simply say that it was drawn to our earth by the attraction of gravity, having been displaced in its course by the action of some quite unknown laws. Would you have him say that its fall at some particular place and time was "ordained and guided without doubt by an intelligent cause on a preconceived and definite plan"? Would you not call this theological pedantry or display?

I believe it is not pedantry in the case of species, simply because their formation has. .h.i.therto been viewed as beyond law; in fact, this branch of science is still with most people under its theological phase of development. The conclusion which I always come to after thinking of such questions is that they are beyond the human intellect; and the less one thinks on them the better. You may say, Then why trouble me? But I should very much like to know clearly what you think.

LETTER 133. TO HENRY FAWCETT.

(133/1. The following letter was published in the "Life" of Mr. Fawcett (1885); we are indebted to Mrs. Fawcett and Messrs. Smith & Elder for permission to reprint it. See Letter 129.)

September 18th [1861].

I wondered who had so kindly sent me the newspaper (133/2. The newspaper sent was the "Manchester Examiner" for September 9th, 1861, containing a report of Mr. Fawcett's address given before Section D of the British a.s.sociation, "On the method of Mr. Darwin in his treatise on the origin of species," in which the speaker showed that the "method of investigation pursued by Mr. Darwin in his treatise on the origin of species is in strict accordance with the principles of logic." The "A"

of the letter (as published in Fawcett's Life) is the late Professor Williamson, who is reported to have said that "while he would not say that Mr. Darwin's book had caused him a loss of reputation, he was sure that it had not caused a gain." The reference to "B" is explained by the report of the late Dr. Lankester's speech in which he said, "The facts brought forward in support of the hypothesis had a very different value indeed from that of the hypothesis...A great naturalist, who was still a friend of Mr. Darwin, once said to him (Dr. Lankester), 'The mistake is, that Darwin has dealt with origin. Why did he not put his facts before us, and let them rest?'" Another speaker, the Rt. Hon. J.R. Napier, remarked: "I am going to speak closely to the question. If the hypothesis is put forward to contradict facts, and the averments are contrary to the Word of G.o.d, I say that it is not a logical argument."

At this point the chairman, Professor Babington, wisely interfered, on the ground that the meeting was a scientific one.), which I was very glad to see; and now I have to thank you sincerely for allowing me to see your MS. It seems to me very good and sound; though I am certainly not an impartial judge. You will have done good service in calling the attention of scientific men to means and laws of philosophising. As far as I could judge by the papers, your opponents were unworthy of you. How miserably A. talked of my reputation, as if that had anything to do with it!...How profoundly ignorant B must be of the very soul of observation!

About thirty years ago there was much talk that geologists ought only to observe and not theorise; and I well remember some one saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colours. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!

I have returned only lately from a two months' visit to Torquay, which did my health at the time good; but I am one of those miserable creatures who are never comfortable for twenty-four hours; and it is clear to me that I ought to be exterminated. I have been rather idle of late, or, speaking more strictly, working at some miscellaneous papers, which, however, have some direct bearing on the subject of species; yet I feel guilty at having neglected my larger book. But, to me, observing is much better sport than writing. I fear that I shall have wearied you with this long note.

Pray believe that I feel sincerely grateful that you have taken up the cudgels in defence of the line of argument in the "Origin;" you will have benefited the subject.

Many are so fearful of speaking out. A German naturalist came here the other day; and he tells me that there are many in Germany on our side, but that all seem fearful of speaking out, and waiting for some one to speak, and then many will follow. The naturalists seem as timid as young ladies should be, about their scientific reputation. There is much discussion on the subject on the Continent, even in quiet Holland; and I had a pamphlet from Moscow the other day by a man who sticks up famously for the imperfection of the "Geological Record," but complains that I have sadly understated the variability of the old fossilised animals!

But I must not run on.

LETTER 134. TO H.W. BATES. Down, September 25th [1861].

Now for a few words on science. Many thanks for facts on neuters. You cannot tell how I rejoice that you do not think what I have said on the subject absurd. Only two persons have even noticed it to me--viz., the bitter sneer of Owen in the "Edinburgh Review" (134/1. "Edinburgh Review," April, 1860, page 525.), and my good friend and supporter, Sir C. Lyell, who could only screw up courage to say, "Well, you have manfully faced the difficulty."

What a wonderful case of Volucella of which I had never heard. (134/2.

Volucella is a fly--one of the Syrphidae--supposed to supply a case of mimicry; this was doubtless the point of interest with Bates. Dr. Sharp says ["Insects," Part II. (in the Camb. Nat. Hist. series), 1899, page 500]: "It was formerly a.s.sumed that the Volucella larvae lived on the larvae of the bees, and that the parent flies were providentially endowed with a bee-like appearance that they might obtain entrance into the bees' nests without being detected." Dr. Sharp goes on to say that what little is known on the subject supports the belief that the "presence of the Volucella in the nests is advantageous to both fly and bee.") I had no idea such a case occurred in nature; I must get and see specimens in British Museum. I hope and suppose you will give a good deal of Natural History in your Travels; every one cares about ants--more notice has been taken about slave-ants in the "Origin" than of any other pa.s.sage.

I fully expect to delight in your Travels. Keep to simple style, as in your excellent letters,--but I beg pardon, I am again advising.

What a capital paper yours will be on mimetic resemblances! You will make quite a new subject of it. I had thought of such cases as a difficulty; and once, when corresponding with Dr. Collingwood, I thought of your explanation; but I drove it from my mind, for I felt that I had not knowledge to judge one way or the other. Dr C., I think, states that the mimetic forms inhabit the same country, but I did not know whether to believe him. What wonderful cases yours seem to be! Could you not give a few woodcuts in your Travels to ill.u.s.trate this? I am tired with a hard day's work, so no more, except to give my sincere thanks and hearty wishes for the success of your Travels.

LETTER 135. TO J.D. HOOKER. Down, March 18th [1862].

Your letter discusses lots of interesting subjects, and I am very glad you have sent for your letter to Bates. (135/1. Published in Mr. Clodd's memoir of Bates in the "Naturalist on the Amazons," 1892, page l.) What do you mean by "individual plants"? (135/2. In a letter to Mr. Darwin dated March 17th, 1862, Sir J.D. Hooker had discussed a supposed difference between animals and plants, "inasmuch as the individual animal is certainly changed materially by external conditions, the latter (I think) never, except in such a coa.r.s.e way as stunting or enlarging--e.g. no increase of cold on the spot, or change of individual plant from hot to cold, will induce said individual plant to get more woolly covering; but I suppose a series of cold seasons would bring about such a change in an individual quadruped, just as rowing will harden hands, etc.") I fancied a bud lived only a year, and you could hardly expect any change in that time; but if you call a tree or plant an individual, you have sporting buds. Perhaps you mean that the whole tree does not change. Tulips, in "breaking," change. Fruit seems certainly affected by the stock. I think I have (135/3. See note, Letter 16.) got cases of slight change in alpine plants transplanted. All these subjects have rather gone out of my head owing to orchids, but I shall soon have to enter on them in earnest when I come again to my volume on variation under domestication.

...In the lifetime of an animal you would, I think, find it very difficult to show effects of external condition on animals more than shade and light, good and bad soil, produce on a plant.

You speak of "an inherent tendency to vary wholly independent of physical conditions"! This is a very simple way of putting the case (as Dr. Prosper Lucas also puts it) (135/4. Prosper Lucas, the author of "Traite philosophique et physiologique de l'heredite naturelle dans les etats de sante et de maladie du systeme nerveux": 2 volumes, Paris, 1847-50.): but two great cla.s.ses of facts make me think that all variability is due to change in the conditions of life: firstly, that there is more variability and more monstrosities (and these graduate into each other) under unnatural domestic conditions than under nature; and, secondly, that changed conditions affect in an especial manner the reproductive organs--those organs which are to produce a new being. But why one seedling out of thousands presents some new character transcends the wildest powers of conjecture. It was in this sense that I spoke of "climate," etc., possibly producing without selection a hooked seed, or any not great variation. (135/5. This statement probably occurs in a letter, and not in Darwin's published works.)

I have for years and years been fighting with myself not to attribute too much to Natural Selection--to attribute something to direct action of conditions; and perhaps I have too much conquered my tendency to lay hardly any stress on conditions of life.

I am not shaken about "saltus" (135/6. Sir Joseph had written, March 17th, 1862: "Huxley is rather disposed to think you have overlooked saltus, but I am not sure that he is right--saltus quoad individuals is not saltus quoad species--as I pointed out in the Begonia case, though perhaps that was rather special pleading in the present state of science." For the Begonia case, see "Life and Letters," II., page 275, also letter 110, page 166.), I did not write without going pretty carefully into all the cases of normal structure in animals resembling monstrosities which appear per saltus.

LETTER 136. TO J.D. HOOKER. 26th [March, 1862].

Thanks also for your own (136/1. See note in Letter 135.) and Bates'

letter now returned. They are both excellent; you have, I think, said all that can be said against direct effects of conditions, and capitally put. But I still stick to my own and Bates' side. Nevertheless I am pleased to attribute little to conditions, and I wish I had done what you suggest--started on the fundamental principle of variation being an innate principle, and afterwards made a few remarks showing that hereafter, perhaps, this principle would be explicable. Whenever my book on poultry, pigeons, ducks, and rabbits is published, with all the measurements and weighings of bones, I think you will see that "use and disuse" at least have some effect. I do not believe in perfect reversion. I rather demur to your doctrine of "centrifugal variation."

(136/2. The "doctrine of centrifugal variation" is given in Sir J.D.

Hooker's "Introductory Essay to the Flora of Tasmania" (Part III. of the Botany of the Antarctic Expedition), 1859, page viii. In paragraph 10 the author writes: "The tendency of varieties, both in nature and under cultivation...is rather to depart more and more widely from the original type than to revert to it." In Sir Joseph's letter to Bates (loc. cit., page lii) he wrote: "Darwin also believes in some reversion to type which is opposed to my view of variation." It may be noted in this connection that Mr. Galton has shown reason to believe in a centripetal tendency in variation (to use Hooker's phraseology) which is not identical with the reversion of cultivated plants to their ancestors, the case to which Hooker apparently refers. See "Natural Inheritance,"

by F. Galton, 1889.) I suppose you do not agree with or do not remember my doctrine of the good of diversification (136/3. Darwin usually used the word "divergence" in this connection.); this seems to me amply to account for variation being centrifugal--if you forget it, look at this discussion (page 117 of 3rd edition), it was the best point which, according to my notions, I made out, and it has always pleased me. It is really curiously satisfactory to me to see so able a man as Bates (and yourself) believing more fully in Natural Selection than I think I even do myself. (136/4. This refers to a very interesting pa.s.sage in Hooker's letter to Bates (loc. cit., page liii): "I am sure that with you, as with me, the more you think the less occasion you will see for anything but time and natural selection to effect change; and that this view is the simplest and clearest in the present state of science is one advantage, at any rate. Indeed, I think that it is, in the present state of the inquiry, the legitimate position to take up; it is time enough to bother our heads with the secondary cause when there is some evidence of it or some demand for it--at present I do not see one or the other, and so feel inclined to renounce any other for the present.") By the way, I always boast to you, and so I think Owen will be wrong that my book will be forgotten in ten years, for a French edition is now going through the press and a second German edition wanted. Your long letter to Bates has set my head working, and makes me repent of the nine months spent on orchids; though I know not why I should not have amused myself on them as well as slaving on bones of ducks and pigeons, etc. The orchids have been splendid sport, though at present I am fearfully sick of them.

I enclose a waste copy of woodcut of Mormodes ignea; I wish you had a plant at Kew, for I am sure its wonderful mechanism and structure would amuse you. Is it not curious the way the labellum sits on the top of the column?--here insects alight and are beautifully shot, when they touch a certain sensitive point, by the pollinia.

How kindly you have helped me in my work! Farewell, my dear old fellow.

LETTER 137. TO H.W. BATES. Down, May 4th [1862].

Hearty thanks for your most interesting letter and three very valuable extracts. I am very glad that you have been looking at the South Temperate insects. I wish that the materials in the British Museum had been richer; but I should think the case of the South American Carabi, supported by some other case, would be worth a paper. To us who theorise I am sure the case is very important. Do the South American Carabi differ more from the other species than do, for instance, the Siberian and European and North American and Himalayan (if the genus exists there)? If they do, I entirely agree with you that the difference would be too great to account for by the recent Glacial period. I agree, also, with you in utterly rejecting an independent origin for these Carabi.

There is a difficulty, as far as I know, in our ignorance whether insects change quickly in time; you could judge of this by knowing how far closely allied coleoptera generally have much restricted ranges, for this almost implies rapid change. What a curious case is offered by land-sh.e.l.ls, which become modified in every sub-district, and have yet retained the same general structure from very remote geological periods!

When working at the Glacial period, I remember feeling much surprised how few birds, no mammals, and very few sea-mollusca seemed to have crossed, or deeply entered, the inter-tropical regions during the cold period. Insects, from all you say, seem to come under the same category.

Plants seem to migrate more readily than animals. Do not underrate the length of Glacial period: Forbes used to argue that it was equivalent to the whole of the Pleistocene period in the warmer lat.i.tudes. I believe, with you, that we shall be driven to an older Glacial period.