190. A.R. WALLACE TO CHARLES DARWIN. Hurstpierpoint, Sussex, July 2nd, 1866…

190. A.R. WALLACE TO CHARLES DARWIN. Hurstpierpoint, Sussex, July 2nd, 1866

I have been so repeatedly struck by the utter inability of numbers of intelligent persons to see clearly, or at all, the self-acting and necessary effects of Natural Selection, that I am led to conclude that the term itself, and your mode of illustrating it, however clear and beautiful to many of us, are yet not the best adapted to impress it on the general naturalist public. The two last cases of the misunderstanding are: (1) the article on "Darwin and his Teachings" in the last "Quarterly Journal of Science," which, though very well written and on the whole appreciative, yet concludes with a charge of something like blindness, in your not seeing that Natural Selection requires the constant watching of an intelligent "chooser," like man's selection to which you so often compare it; and (2) in Janet's recent work on the "Materialism of the Present Day," reviewed in last Saturday's "Reader," by an extract from which I see that he considers your weak point to be that you do not see that "thought and direction are essential to the action of Natural Selection." The same objection has been made a score of times by your chief opponents, and I have heard it as often stated myself in conversation. Now, I think this arises almost entirely from your choice of the term "Natural Selection" and so constantly comparing it in its effects to Man's Selection, and also your so frequently personifying nature as "selecting," as "preferring," as "seeking only the good of the species," etc., etc. To the few this is as clear as daylight, and beautifully suggestive, but to many it is evidently a stumbling-block. I wish, therefore, to suggest to you the possibility of entirely avoiding this source of misconception in your great work (if not now too late), and also in any future editions of the "Origin," and I think it may be done without difficulty and very effectually by adopting Spencer's term (which he generally uses in preference to Natural Selection)--viz., "survival of the fittest."

This term is the plain expression of the fact; Natural Selection is a metaphorical expression of it, and to a certain degree indirect and incorrect, since, even personifying Nature, she does not so much select special variations as exterminate the most unfavourable ones.

Combined with the enormous multiplying powers of all organisms, and the "struggle for existence" leading to the constant destruction of by far the largest proportion--facts which no one of your opponents, as far as I am aware, has denied or misunderstood--"the survival of the fittest" rather than of those who were less fit could not possibly be denied or misunderstood. Neither would it be possible to say that to ensure the "survival of the fittest" any intelligent chooser was necessary; whereas when you say Natural Selection acts so as to choose those that are fittest, it IS misunderstood, and apparently always will be. Referring to your book, I find such expressions as "Man selects only for his own good; Nature only for that of the being which she tends." This, it seems, will always be misunderstood; but if you had said "Man selects only for his own good; Nature, by the inevitable 'survival of the fittest,' only for that of the being she tends," it would have been less liable to be so.

I find you use the term "Natural Selection" in two senses: (1) for the simple preservation of favourable and rejection of unfavourable variations, in which case it is equivalent to "survival of the fittest"; and (2) for the effect or change produced by this preservation, as when you say, "To sum up the circumstances favourable or unfavourable to Natural Selection," and again, "Isolation, also, is an important element in the process of Natural Selection." Here it is not merely "survival of the fittest," but change produced by survival of the fittest, that is meant. On looking over your fourth chapter, I find that these alterations of terms can be in most cases easily made, while in some cases the addition of "or survival of the fittest" after "Natural Selection" would be best; and in others, less likely to be misunderstood, the original term may stand alone.

I could not venture to propose to any other person so great an alteration of terms, but you, I am sure, will give it an impartial consideration, and if you really think the change will produce a better understanding of your work, will not hesitate to adopt it.

It is evidently also necessary not to personify "Nature" too much--though I am very apt to do it myself--since people will not understand that all such phrases are metaphors. Natural Selection is, when understood, so necessary and self-evident a principle, that it is a pity it should be in any way obscured; and it therefore seems to me that the free use of "survival of the fittest," which is a compact and accurate definition of it, would tend much to its being more widely accepted, and prevent it being so much misrepresented and misunderstood.

There is another objection made by Janet which is also a very common one. It is that the chances are almost infinite against the particular kind of variation required being coincident with each change of external conditions, to enable an animal to become modified by Natural Selection in harmony with such changed conditions; especially when we consider that, to have produced the almost infinite modifications of organic beings, this coincidence must have taken place an almost infinite number of times.

Now, it seems to me that you have yourself led to this objection being made, by so often stating the case too strongly against yourself. For example, at the commencement of Chapter IV. you ask if it is "improbable that useful variations should sometimes occur in the course of thousands of generations"; and a little further on you say, "unless profitable variations do occur, Natural Selection can do nothing." Now, such expressions have given your opponents the advantage of assuming that favourable variations are rare accidents, or may even for long periods never occur at all, and thus Janet's argument would appear to many to have great force. I think it would be better to do away with all such qualifying expressions, and constantly maintain (what I certainly believe to be the fact) that variations of every kind are always occurring in every part of every species, and therefore that favourable variations are always ready when wanted. You have, I am sure, abundant materials to prove this; and it is, I believe, the grand fact that renders modification and adaptation to conditions almost always possible. I would put the burthen of proof on my opponents to show that any one organ, structure, or faculty does not vary, even during one generation, among all the individuals of a species; and also to show any mode or way in which any such organ, etc., does not vary. I would ask them to give any reason for supposing that any organ, etc., is ever absolutely identical at any one time in all the individuals of a species, and if not then it is always varying, and there are always materials which, from the simple fact that "the fittest survive," will tend to the modification of the race into harmony with changed conditions.

I hope these remarks may be intelligible to you, and that you will be so kind as to let me know what you think of them.

I have not heard for some time how you are getting on. I hope you are still improving in health, and that you will now be able to get on with your great work, for which so many thousands are looking with interest.

191. TO A.R. WALLACE

(191/1. From "Life and Letters," III., page 45.)

Down, July 5th [1866].

I have been much interested by your letter, which is as clear as daylight. I fully agree with all that you say on the advantages of H. Spencer's excellent expression of "the survival of the fittest." This, however, had not occurred to me till reading your letter. It is, however, a great objection to this term that it cannot be used as a substantive governing a verb; and that this is a real objection I infer from H. Spencer continually using the words Natural Selection. I formerly thought, probably in an exaggerated degree, that it was a great advantage to bring into connection natural and artificial selection; this indeed led me to use a term in common, and I still think it some advantage. I wish I had received your letter two months ago, for I would have worked in "the survival," etc., often in the new edition of the "Origin," which is now almost printed off, and of which I will of course send you a copy. I will use the term in my next book on domestic animals, etc., from which, by the way, I plainly see that you expect MUCH too much. The term Natural Selection has now been so largely used abroad and at home that I doubt whether it could be given up, and with all its faults I should be sorry to see the attempt made. Whether it will be rejected must now depend "on the survival of the fittest." As in time the term must grow intelligible the objections to its use will grow weaker and weaker. I doubt whether the use of any term would have made the subject intelligible to some minds, clear as it is to others; for do we not see even to the present day Malthus on Population absurdly misunderstood? This reflection about Malthus has often comforted me when I have been vexed at this misstatement of my views. As for M. Janet, he is a metaphysician, and such gentlemen are so acute that I think they often misunderstand common folk. Your criticism on the double sense in which I have used Natural Selection is new to me and unanswerable; but my blunder has done no harm, for I do not believe that any one, excepting you, has ever observed it. Again, I agree that I have said too much about "favourable variations," but I am inclined to think that you put the opposite side too strongly: if every part of every being varied, I do not think we should see the same end or object gained by such wonderfully diversified means.

I hope you are enjoying the country, and are in good health, and are working hard at your "Malay Archipelago" book, for I will always put this wish in every note I write to you, as some good people always put in a text. My health keeps much the same, or rather improves, and I am able to work some hours daily.

192. TO C. LYELL. Down, October 9th [1866]

One line to say that I have received your note and the proofs safely, and will read them with the greatest pleasure; but I am certain I shall not be able to send any criticism on the astronomical chapter (192/1. "Principles of Geology," by Sir Charles Lyell; Edition X., London, 1867. Chapter XIII. deals with "Vicissitudes in Climate how far influenced by Astronomical Causes."), as I am as ignorant as a pig on this head. I shall require some days to read what has been sent. I have just read Chapter IX. (192/2. Chapter IX., "Theory of the Progressive Development of Organic Life at Successive Geological Periods."), and like it extremely; it all seems to me very clear, cautious, and sagacious. You do not allude to one very striking point enough, or at all--viz., the classes having been formerly less differentiated than they now are; and this specialisation of classes must, we may conclude, fit them for different general habits of life as well as the specialisation of particular organs.

Page 162 (192/3. On page 163 Lyell refers to the absence of Cetacea in Secondary rocks, and expresses the opinion that their absence "is a negative fact of great significance, which seems more than any other to render it highly improbable that we shall ever find air-breathers of the highest class in any of the Primary strata, or in any of the older members of the Secondary series.") I rather demur to your argument from Cetacea: as they are such greatly modified mammals, they ought to have come in rather later in the series. You will think me rather impudent, but the discussion at the end of Chapter IX. on man (192/4. Loc. cit., pages 167-73, "Introduction of Man, to what extent a Change of the System."), who thinks so much of his fine self, seems to me too long, or rather superfluous, and too orthodox, except for the beneficed clergy.

193. TO V. CARUS

(193/1. The following letter refers to the 4th edition of the "Origin," 1866, which was translated by Professor Carus, and formed the 3rd German edition. Carus continued to translate Darwin's books, and a strong bond of friendship grew up between author and translator (see "Life and Letters," III., page 48). Nageli's pamphlet was first noticed in the 5th English edition.)

Down, November 21st, 1866.

...With respect to a note on Nageli (193/2. "Entstehung und Begriff der Naturhistorischen Art," an Address given before the Royal Academy of Sciences at Munich, March 28th, 1865. See "Life and Letters," III., page 50, for Mr. Darwin's letter to the late Prof. Nageli.) I find on consideration it would be too long; for so good a pamphlet ought to be discussed at full length or not at all. He makes a mistake in supposing that I say that useful characters are always constant. His view about distinct species converging and acquiring the same identical structure is by implication answered in the discussion which I have given on the endless diversity of means for gaining the same end.

The most important point, as it seems to me, in the pamphlet is that on the morphological characters of plants, and I find I could not answer this without going into much detail.

The answer would be, as it seems to me, that important morphological characters, such as the position of the ovules and the relative position of the stamens to the ovarium (hypogynous, perigynous, etc.) are sometimes variable in the same species, as I incidentally mention when treating of the ray-florets in the Compositae and Umbelliferae; and I do not see how Nageli could maintain that differences in such characters prove an inherent tendency towards perfection. I see that I have forgotten to say that you have my fullest consent to append any discussion which you may think fit to the new edition. As for myself I cannot believe in spontaneous generation, and though I expect that at some future time the principle of life will be rendered intelligible, at present it seems to me beyond the confines of science.

194. TO T.H. HUXLEY. Down, December 22nd [1866?]

I suppose that you have received Hackel's book (194/1. "Generelle Morphologie," 1866.) some time ago, as I have done. Whenever you have had time to read through some of it, enough to judge by, I shall be very curious to hear your judgment. I have been able to read a page or two here and there, and have been interested and instructed by parts. But my vague impression is that too much space is given to methodical details, and I can find hardly any facts or detailed new views. The number of new words, to a man like myself, weak in his Greek, is something dreadful. He seems to have a passion for defining, I daresay very well, and for coining new words. From my very vague notions on the book, and from its immense size, I should fear a translation was out of the question. I see he often quotes both of us with praise. I am sure I should like the book much, if I could read it straight off instead of groaning and swearing at each sentence. I have not yet had time to read your Physiology (194/2. "Lessons in Elementary Physiology," 1866.) book, except one chapter; but I have just re-read your book on "Man's Place, etc.," and I think I admire it more this second time even than the first. I doubt whether you will ever have time, but if ever you have, do read the chapter on hybridism in the new edition of the "Origin" (194/3. Fourth Edition (1866).), for I am very anxious to make you think less seriously on that difficulty. I have improved the chapter a good deal, I think, and have come to more definite views. Asa Gray and Fritz Muller (the latter especially) think that the new facts on illegitimate offspring of dimorphic plants, throw much indirect light on the subject. Now that I have worked up domestic animals, I am convinced of the truth of the Pallasian (194/4. See Letter 80.) view of loss of sterility under domestication, and this seems to me to explain much. But I had no intention, when I began this note, of running on at such length on hybridism; but you have been Objector-General on this head.

195. TO T. RIVERS

(195/1. For another letter of Mr. Darwin's to him see "Life and Letters," III., page 57.)

Down, December 23rd [1866?].

I do not know whether you will forgive a stranger addressing you. My name may possibly be known to you. I am now writing a book on the variation of animals and plants under domestication; and there is one little piece of information which it is more likely that you could give me than any man in the world, if you can spare half an hour from your professional labours, and are inclined to be so kind. I am collecting all accounts of what some call "sports," that is, of what I shall call "bud-variations," i.e. a moss-rose suddenly appearing on a Provence rose--a nectarine on a peach, etc. Now, what I want to know, and which is not likely to be recorded in print, is whether very slight differences, too slight to be worth propagating, thus appear suddenly by buds. As every one knows, in raising seedlings you may have every gradation from individuals identical with the parent, to slight varieties, to strongly marked varieties. Now, does this occur with buds or do only rather strongly marked varieties thus appear at rare intervals of time by buds? (195/2. Mr. Rivers could not give a decided answer, but he did not remember to have seen slight bud-variations. The question is discussed in "Variation under Domestication," Edition II., Volume I., page 443.) I should be most grateful for information. I may add that if you have observed in your enormous experience any remarkable "bud-variations," and could spare time to inform me, and allow me to quote them on your authority, it would be the greatest favour. I feel sure that these "bud-variations" are most interesting to any one endeavouring to make out what little can be made out on the obscure subject of variation.

196. TO T. RIVERS. Down, January 7th [1867?]

I thank you much for your letter and the parcel of shoots. The case of the yellow plum is a treasure, and is now safely recorded on your authority in its proper place, in contrast with A. Knight's case of the yellow magnum bonum sporting into red. (196/1. See "Variation under Domestication," Edition II., Volume I., page 399.) I could see no difference in the shoots, except that those of the yellow were thicker, and I presume that this is merely accidental: as you do not mention it, I further presume that there are no further differences in leaves or flowers of the two plums. I am very glad to hear about the yellow ash, and that you yourself have seen the jessamine case. I must confess that I hardly fully believed in it; but now I do, and very surprising it is.

In an old French book, published in Amsterdam in 1786 (I think), there is an account, apparently authentic and attested by the writer as an eye-witness, of hyacinth bulbs of two colours being cut in two and grafted, and they sent up single stalks with differently coloured flowers on the two sides, and some flowers parti-coloured. I once thought of offering 5 pounds reward in the "Cottage Gardener" for such a plant; but perhaps it would seem too foolish. No instructions are given when to perform the operation; I have tried two or three times, and utterly failed. I find that I have a grand list of "bud-variations," and to-morrow shall work up such cases as I have about rose-sports, which seem very numerous, and which I see you state to occur comparatively frequently.

When a person is very good-natured he gets much pestered--a discovery which I daresay you have made, or anyhow will soon make; for I do want very much to know whether you have sown seed of any moss-roses, and whether the seedlings were moss-roses. (196/2. Moss-roses can be raised from seed ("Variation under Domestication," Edition II., Volume I., page 405.) Has a common rose produced by SEED a moss-rose?

If any light comes to you about very slight changes in the buds, pray have the kindness to illuminate me. I have cases of seven or eight varieties of the peach which have produced by "bud-variation" nectarines, and yet only one single case (in France) of a peach producing another closely similar peach (but later in ripening). How strange it is that a great change in the peach should occur not rarely and slighter changes apparently very rarely! How strange that no case seems recorded of new apples or pears or apricots by "bud-variation"! How ignorant we are! But with the many good observers now living our children's children will be less ignorant, and that is a comfort.

197. TO T.H. HUXLEY. Down, January 7th [1867]

Very many thanks for your letter, which has told me exactly what I wanted to know. I shall give up all thoughts of trying to get the book (197/1. Hackel's "Generelle Morphologie," 1866. See "Life and Letters," III., pages 67, 68.) translated, for I am well convinced that it would be hopeless without too great an outlay. I much regret this, as I should think the work would be useful, and I am sure it would be to me, as I shall never be able to wade through more than here and there a page of the original. To all people I cannot but think that the number of new terms would be a great evil. I must write to him. I suppose you know his address, but in case you do not, it is "to care of Signor Nicolaus Krohn, Madeira." I have sent the MS. of my big book (197/2. "The Variation of Animals and Plants under Domestication," 1868.), and horridly, disgustingly big it will be, to the printers, but I do not suppose it will be published, owing to Murray's idea on seasons, till next November. I am thinking of a chapter on Man, as there has lately been so much said on Natural Selection in relation to man. I have not seen the Duke's (or Dukelet's? how can you speak so of a living real Duke?) book, but must get it from Mudie, as you say he attacks us. (197/3. "The Reign of Law" (1867), by the late Duke of Argyll. See "Life and Letters," III., page 65.)

P.S.--Nature never made species mutually sterile by selection, nor will men.

197. TO E. HACKEL. Down, January 8th [1867]

I received some weeks ago your great work (198/1. "Generelle Morphologie," 1866.); I have read several parts, but I am too poor a German scholar and the book is too large for me to read it all. I cannot tell you how much I regret this, for I am sure that nearly the whole would interest me greatly, and I have already found several parts very useful, such as the discussion on cells and on the different forms of reproduction. I feel sure, after considering the subject deliberately and after consulting with Huxley, that it would be hopeless to endeavour to get a publisher to print an English translation; the work is too profound and too long for our English countrymen. The number of new terms would also, I am sure, tell much against its sale; and, indeed, I wish for my own sake that you had printed a glossary of all the new terms which you use. I fully expect that your book will be highly successful in Germany, and the manner in which you often refer to me in your text, and your dedication and the title, I shall always look at as one of the greatest honours conferred on me during my life. (198/2. As regards the dedication and title this seems a strong expression. The title is "Generelle Morphologie der Organismen. Allgemeine Grundzuge der organischen Formen-Wissenschaft mechanisch begrundet durch die von Charles Darwin reformirte Descendenz-Theorie." The dedication of the second volume is "Den Begrundern der Descendenz-Theorie, den denkenden Naturforschern, Charles Darwin, Wolfgang Goethe, Jean Lamarck widmet diese Grundzuge der Allgemeinen Entwickelungsgeschichte in vorzuglicher Verehrung, der Verfasser.")

I sincerely hope that you have had a prosperous expedition, and have met with many new and interesting animals. If you have spare time I should much like to hear what you have been doing and observing. As for myself, I have sent the MS. of my book on domestic animals, etc., to the printers. It turns out to be much too large; it will not be published, I suppose, until next November. I find that we have discussed several of the same subjects, and I think we agree on most points fairly well. I have lately heard several times from Fritz Muller, but he seems now chiefly to be working on plants. I often think of your visit to this house, which I enjoyed extremely, and it will ever be to me a real pleasure to remember our acquaintance. From what I heard in London I think you made many friends there. Shall you return through England? If so, and you can spare the time, we shall all be delighted to see you here again.

199. TO T. RIVERS. Down, January 11th [1867?]

How rich and valuable a letter you have most kindly sent me! The case of Baronne Prevost (199/1. See "Variation under Domestication," Edition II., Volume I., page 406. Mr. Rivers had a new French rose with a delicate smooth stem, pale glaucous leaves and striped flesh-coloured flowers; on branches thus characterised there appeared "the famous old rose called 'Baronne Prevost,'" with its stout thorny stem and uniform rich-coloured double flowers.), with its different shoots, foliage, spines, and flowers, will be grand to quote. I am extremely glad to hear about the seedling moss-roses. That case of a seedling like a Scotch rose, unless you are sure that no Scotch rose grew near (and it is unlikely that you can remember), must, one would think, have been a cross.

I have little compunction for being so troublesome--not more than a grand Inquisitor has in torturing a heretic--for am I not doing a real good public service in screwing crumbs of knowledge out of your wealth of information?

P.S. Since the above was written I have read your paper in the "Gardeners' Chronicle": it is admirable, and will, I know, be a treasure to me. I did not at all know how strictly the character of so many flowers is inherited.

On my honour, when I began this note I had no thought of troubling you with a question; but you mention one point so interesting, and which I have had occasion to notice, that I must supplicate for a few more facts to quote on your authority. You say that you have one or two seedling peaches (199/2. "On raising Peaches, Nectarines, and other Fruits from Seed." By Thomas Rivers, Sawbridgeworth.--"Gard. Chron." 1866, page 731.) approaching very nearly to thick-fleshed almonds (I know about A. Knight and the Italian hybrid cases). Now, did any almond grow near your mother peach? But especially I want to know whether you remember what shape the stone was, whether flattened like that of an almond; this, botanically, seems the most important distinction. I earnestly wish to quote this. Was the flesh at all sweet?

Forgive if you can.

Have you kept these seedling peaches? if you would give me next summer a fruit, I want to have it engraved.

200. TO I. ANDERSON-HENRY. May 22nd [1867]

You are so kind as to offer to lend me Maillet's (200/1. For De Maillet see Mr. Huxley's review on "The Origin of Species" in the "Westminster Review," 1860, reprinted in "Lay Sermons," 1870, page 314. De Maillet's evolutionary views were published after his death in 1748 under the name of Telliamed (De Maillet spelt backwards).) work, which I have often heard of, but never seen. I should like to have a look at it, and would return it to you in a short time. I am bound to read it, as my former friend and present bitter enemy Owen generally ranks me and Maillet as a pair of equal fools.

201. TO J.D. HOOKER. Down, April 4th [1867]

You have done me a very great service in sending me the pages of the "Farmer." I do not know whether you wish it returned; but I will keep it unless I hear that you want it. Old I. Anderson-Henry passes a magnificent but rather absurd eulogium on me; but the point of such extreme value in my eyes is Mr. Traill's (201/1. Mr. Traill's results are given at page 420 of "Animals and Plants," Edition II., Volume I. In the "Life and Letters of G.J. Romanes," 1896, an interesting correspondence is published with Mr. Darwin on this subject. The plan of the experiments suggested to Romanes was to raise seedlings from graft-hybrids: if the seminal offspring of plants hybridised by grafting should show the hybrid character, it would be striking evidence in favour of pangenesis. The experiment, however, did not succeed.) statement that he made a mottled mongrel by cutting eyes through and joining two kinds of potatoes. (201/2. For an account of similar experiments now in progress, see a "Note on some Grafting Experiments" by R. Biffen in the "Annals of Botany," Volume XVI., page 174, 1902.) I have written to him for full information, and then I will set to work on a similar trial. It would prove, I think, to demonstration that propagation by buds and by the sexual elements are essentially the same process, as pangenesis in the most solemn manner declares to be the case.

202. TO T.H. HUXLEY. Down, June 12th [1867?]

We come up on Saturday, the 15th, for a week. I want much to see you for a short time to talk about my youngest boy and the School of Mines. I know it is rather unreasonable, but you must let me come a little after 10 o'clock on Sunday morning, the 16th. If in any way inconvenient, send me a line to "6, Queen Anne Street W.,"; but if I do not hear, I will (stomacho volente) call, but I will not stay very long and spoil your whole morning as a holiday. Will you turn two or three times in your mind this question: what I called "pangenesis" means that each cell throws off an atom of its contents or a gemmule, and that these aggregated form the true ovule or bud, etc.? Now I want to know whether I could not invent a better word. "Cyttarogenesis" (202/1. From kuttaros, a bee's-cell: cytogenesis would be a natural form of the word from kutos.)--i.e. cell-genesis--is more true and expressive, but long. "Atomogenesis" sounds rather better, I think, but an "atom" is an object which cannot be divided; and the term might refer to the origin of atoms of inorganic matter. I believe I like "pangenesis" best, though so indefinite; and though my wife says it sounds wicked, like pantheism; but I am so familiar now with this word, that I cannot judge. I supplicate you to help me.

203. TO A.R. WALLACE. Down, October, 12th and 13th [1867]

I ordered the journal (203/1. "Quarterly Journal of Science," October, 1867, page 472. A review of the Duke of Argyll's "Reign of Law.") a long time ago, but by some oversight received it only yesterday, and read it. You will think my praise not worth having, from being so indiscriminate; but if I am to speak the truth, I must say I admire every word. You have just touched on the points which I particularly wished to see noticed. I am glad you had the courage to take up Angraecum (203/2. Angraecum sesquipedale, a Madagascan orchid, with a whiplike nectary, 11 to 12 inches in length, which, according to Darwin ("Fertilisation of Orchids," Edition II., page 163), is adapted to the visits of a moth with a proboscis of corresponding length. He points out that there is no difficulty in believing in the existence of such a moth as F. Muller has described ("Nature," 1873, page 223)--a Brazilian sphinx-moth with a trunk of 10 to 11 inches in length. Moreover, Forbes has given evidence to show that such an insect does exist in Madagascar ("Nature," VIII., 1873, page 121). The case of Angraecum was put forward by the Duke of Argyll as being necessarily due to the personal contrivance of the Deity. Mr. Wallace (page 476) shows that both proboscis and nectary might be increased in length by means of Natural Selection. It may be added that Hermann Muller has shown good grounds for believing that mutual specialisation of this kind is beneficial both to insect and plant.) after the Duke's attack; for I believe the principle in this case may be widely applied. I like the figure, but I wish the artist had drawn a better sphinx. With respect to beauty, your remarks on hideous objects and on flowers not being made beautiful except when of practical use to them, strike me as very good. On this one point of beauty I can hardly think that the Duke was quite candid. I have used in the concluding paragraph of my present book precisely the same argument as you have, even bringing in the bull-dog (203/3. "Variation of Animals and Plants," Edition I., Volume II., page 431: "Did He cause the frame and mental qualities of the dog to vary in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man's brutal sport?"), with respect to variations not having been specially ordained. Your metaphor of the river (203/4. See Wallace, op. cit., pages 477-8. He imagines an observer examining a great river-system, and finding everywhere adaptations which reveal the design of the Creator. "He would see special adaptation to the wants of man in broad, quiet, navigable rivers, through fertile alluvial plains that would support a large population, while the rocky streams and mountain torrents were confined to those sterile regions suitable only for a small population of shepherds and herdsmen.') is new to me, and admirable; but your other metaphor, in which you compare classification and complex machines, does not seem to me quite appropriate, though I cannot point out what seems deficient. The point which seems to me strong is that all naturalists admit that there is a natural classification, and it is this which descent explains. I wish you had insisted a little more against the "North British" (203/5. At page 485 Mr. Wallace deals with Fleeming Jenkin's review in the "North British Review," 1867. The review strives to show that there are strict limits to variation, since the most rigorous and long-continued selection does not indefinitely increase such a quality as the fleetness of a racehorse. On this Mr. Wallace remarks that "this argument fails to meet the real question," which is, not whether indefinite change is possible, "but whether such differences as do occur in nature could have been produced by the accumulation of variations by selection.") on the reviewer assuming that each variation which appears is a strongly marked one; though by implication you have made this very plain. Nothing in your whole article has struck me more than your view with respect to the limit of fleetness in the racehorse and other such cases: I shall try and quote you on this head in the proof of my concluding chapter. I quite missed this explanation, though in the case of wheat I hit upon something analogous. I am glad you praise the Duke's book, for I was much struck with it. The part about flight seemed to me at first very good; but as the wing is articulated by a ball-and-socket joint, I suspect the Duke would find it very difficult to give any reason against the belief that the wing strikes the air more or less obliquely. I have been very glad to see your article and the drawing of the butterfly in "Science Gossip." By the way, I cannot but think that you push protection too far in some cases, as with the stripes on the tiger. I have also this morning read an excellent abstract in the "Gardeners' Chronicle" of your paper on nests. (203/6. An abstract of a paper on "Birds' Nests and Plumage," read before the British Association: see "Gard. Chron." 1867, page 1047.) I was not by any means fully converted by your letter, but I think now I am so; and I hope it will be published somewhere in extenso. It strikes me as a capital generalisation, and appears to me even more original than it did at first...

I have finished Volume I. of my book ["Variation of Animals and Plants"], and I hope the whole will be out by the end of November. If you have the patience to read it through, which is very doubtful, you will find, I think, a large accumulation of facts which will be of service to you in future papers; and they could not be put to better use, for you certainly are a master in the noble art of reasoning.

204. TO T.H. HUXLEY. Down, October 3rd [no date]

I know you have no time for speculative correspondence; and I did not in the least expect an answer to my last. But I am very glad to have had it, for in my eclectic work the opinions of the few good men are of great value to me.

I knew, of course, of the Cuvierian view of classification (204/1. Cuvier proved that "animals cannot be arranged in a single series, but that there are several distinct plans of organisation to be observed among them, no one of which, in its highest and most complicated modification, leads to any of the others" (Huxley's "Darwiniana," page 215).); but I think that most naturalists look for something further, and search for "the natural system,"--"for the plan on which the Creator has worked," etc., etc. It is this further element which I believe to be simply genealogical.

But I should be very glad to have your answer (either when we meet or by note) to the following case, taken by itself, and not allowing yourself to look any further than to the point in question. Grant all races of man descended from one race--grant that all the structure of each race of man were perfectly known--grant that a perfect table of the descent of each race was perfectly known--grant all this, and then do you not think that most would prefer as the best classification, a genealogical one, even if it did occasionally put one race not quite so near to another, as it would have stood, if collocated by structure alone? Generally, we may safely presume, that the resemblance of races and their pedigrees would go together.

I should like to hear what you would say on this purely theoretical case.

It might be asked why is development so all-potent in classification, as I fully admit it is? I believe it is because it depends on, and best betrays, genealogical descent; but this is too large a point to enter on.

205. TO C. LYELL. Down, December 7th [1867]

I send by this post the article in the Victorian Institute with respect to frogs' spawn. If you remember in your boyhood having ever tried to take a small portion out of the water, you will remember that it is most difficult. I believe all the birds in the world might alight every day on the spawn of batrachians, and never transport a single ovum. With respect to the young of molluscs, undoubtedly if the bird to which they were attached alighted on the sea, they would be instantly killed; but a land-bird would, I should think, never alight except under dire necessity from fatigue. This, however, has been observed near Heligoland (205/1. Instances are recorded by Gatke in his "Heligoland as an Ornithological Observatory" (translated by Rudolph Rosenstock, Edinburgh, 1895) of land-birds, such as thrushes, buntings, finches, etc., resting for a short time on the surface of the water. The author describes observations made by himself about two miles west of Heligoland (page 129).); and land-birds, after resting for a time on the tranquil sea, have been seen to rise and continue their flight. I cannot give you the reference about Heligoland without much searching. This alighting on the sea may aid you in your unexpected difficulty of the too-easy diffusion of land-molluscs by the agency of birds. I much enjoyed my morning's talk with you.

206. TO F. HILDEBRAND. Down, January 5th [1868]

I thank you for your letter, which has quite delighted me. I sincerely congratulate you on your success in making a graft-hybrid (206/1. Prof. Hildebrand's paper is in the "Bot. Zeitung," 1868: the substance is given in "Variation of Animals and Plants," Edition II., Volume I., page 420.), for I believe it to be a most important observation. I trust that you will publish full details on this subject and on the direct action of pollen (206/2. See Prof. Hildebrand, "Bot. Zeitung," 1868, and "Variation of Animals and Plants," Edition II., Volume I., page 430. A yellow-grained maize was fertilised with pollen from a brown-grained one; the result was that ears were produced bearing both yellow and dark-coloured grains.): I hope that you will be so kind as to send me a copy of your paper. If I had succeeded in making a graft-hybrid of the potato, I had intended to raise seedlings from the graft-hybrid and from the two parent-forms (excluding insects) and carefully compare the offspring. This, however, would be difficult on account of the sterility and variability of the potato. When in the course of a few months you receive my second volume (206/3. This sentence may be paraphrased--"When you receive my book and read the second volume."), you will see why I think these two subjects so important. They have led me to form a hypothesis on the various forms of reproduction, development, inheritance, etc., which hypothesis, I believe, will ultimately be accepted, though how it will be now received I am very doubtful.

Once again I congratulate you on your success.

207. TO J.D. HOOKER. Down, January 6th [1868]

Many thanks about names of plants, synonyms, and male flowers--all that I wanted.

I have been glad to see Watson's letter, and am sorry he is a renegade about Natural Selection. It is, as you say, characteristic, with the final fling at you.

His difficulty about the difference between the two genera of St. Helena Umbellifers is exactly the same as what Nageli has urged in an able pamphlet (207/1. "Ueber Entstehung und Begriff der naturhist. Art." "Sitz. der K. Bayer. Akad. Der Wiss. zu Munchen," 1865. Some of Nageli's points are discussed in the "Origin," Edition V., page 151.), and who in consequence maintains that there is some unknown innate tendency to progression in all organisms. I said in a letter to him that of course I could not in the least explain such cases; but that they did not seem to me of overwhelming force, as long as we are quite ignorant of the meaning of such structures, whether they are of any service to the plants, or inevitable consequences of modifications in other parts.

I cannot understand what Watson means by the "counter-balance in nature" to divergent variation. There is the counterbalance of crossing, of which my present work daily leads me to see more and more the efficiency; but I suppose he means something very different. Further, I believe variation to be divergent solely because diversified forms can best subsist. But you will think me a bore.

I enclose half a letter from F. Muller (which please return) for the chance of your liking to see it; though I have doubted much about sending it, as you are so overworked. I imagine the Solanum-like flower is curious.

I heard yesterday to my joy that Dr. Hildebrand has been experimenting on the direct action of pollen on the mother-plant with success. He has also succeeded in making a true graft-hybrid between two varieties of potatoes, in which I failed. I look at this as splendid for pangenesis, as being strong evidence that bud-reproduction and seminal reproduction do not essentially differ.

My book is horribly delayed, owing to the accursed index-maker. (207/2. Darwin thoroughly appreciated the good work put into the index of "The Variation of Animals and Plants.") I have almost forgotten it!

208. TO T.H. HUXLEY. Down, January 30th [1868]

Most sincere thanks for your kind congratulations. I never received a note from you in my life without pleasure; but whether this will be so after you have read pangenesis (208/1. In Volume II. of "Animals and Plants, 1868.), I am very doubtful. Oh Lord, what a blowing up I may receive! I write now partly to say that you must not think of looking at my book till the summer, when I hope you will read pangenesis, for I care for your opinion on such a subject more than for that of any other man in Europe. You are so terribly sharp-sighted and so confoundedly honest! But to the day of my death I will always maintain that you have been too sharp-sighted on hybridism; and the chapter on the subject in my book I should like you to read: not that, as I fear, it will produce any good effect, and be hanged to you.

I rejoice that your children are all pretty well. Give Mrs. Huxley the enclosed (208/2. Queries on Expression.), and ask her to look out when one of her children is struggling and just going to burst out crying. A dear young lady near here plagued a very young child for my sake, till it cried, and saw the eyebrows for a second or two beautifully oblique, just before the torrent of tears began.

The sympathy of all our friends about George's success (it is the young Herald) (208/3. His son George was Second Wrangler in 1868; as a boy he was an enthusiast in heraldry.) has been a wonderful pleasure to us. George has not slaved himself, which makes his success the more satisfactory. Farewell, my dear Huxley, and do not kill yourself with work.

(209/1. The following group of letters deals with the problem of the causes of the sterility of hybrids. Mr. Darwin's final view is given in the "Origin," sixth edition (page 384, edition 1900). He acknowledges that it would be advantageous to two incipient species, if by physiological isolation due to mutual sterility, they could be kept from blending: but he continues, "After mature reflection it seems to me that this could not have been effected through Natural Selection." And finally he concludes (page 386):--

"But it would be superfluous to discuss this question in detail; for with plants we have conclusive evidence that the sterility of crossed species must be due to some principle quite independent of Natural Selection. Both Gartner and Kolreuter have proved that in genera including numerous species, a series can be formed from species which when crossed yield fewer and fewer seeds, to species which never produce a single seed, but yet are affected by the pollen of certain other species, for the germen swells. It is here manifestly impossible to select the more sterile individuals, which have already ceased to yield seeds; so that this acme of sterility, when the germen alone is affected, cannot have been gained through selection; and from the laws governing the various grades of sterility being so uniform throughout the animal and vegetable kingdoms, we may infer that the cause, whatever it may be, is the same or nearly the same in all cases."

Mr. Wallace, on the other hand, still adheres to his view: see his "Darwinism," 1889, page 174, and for a more recent statement see page 292, note 1, Letter 211, and page 299.

The discussion of 1868 began with a letter from Mr. Wallace, written towards the end of February, giving his opinion on the "Variation of Animals and Plants;" the discussion on the sterility of hybrids is at page 185, Volume II., of the first edition.)

209. A.R. WALLACE TO CHARLES DARWIN. February 1868

The only parts I have yet met with where I somewhat differ from your views, are in the chapter on the causes of variability, in which I think several of your arguments are unsound: but this is too long a subject to go into now. Also, I do not see your objection to sterility between allied species having been aided by Natural Selection. It appears to me that, given a differentiation of a species into two forms, each of which was adapted to a special sphere of existence, every slight degree of sterility would be a positive advantage, not to the individuals who were sterile, but to each form. If you work it out, and suppose the two incipient species a...b to be divided into two groups, one of which contains those which are fertile when the two are crossed, the other being slightly sterile, you will find that the latter will certainly supplant the former in the struggle for existence; remembering that you have shown that in such a cross the offspring would be more vigorous than the pure breed, and therefore would certainly soon supplant them, and as these would not be so well adapted to any special sphere of existence as the pure species a and b, they would certainly in their turn give way to a and b.

210. TO A.R. WALLACE. February 27th [1868]

I shall be very glad to hear, at some future day, your criticisms on the "causes of variability." Indeed, I feel sure that I am right about sterility and Natural Selection. Two of my grown-up children who are acute reasoners have two or three times at intervals tried to prove me wrong; and when your letter came they had another try, but ended by coming back to my side. I do not quite understand your case, and we think that a word or two is misplaced. I wish some time you would consider the case under the following point of view. If sterility is caused or accumulated through Natural Selection, then, as every degree exists up to absolute barrenness, Natural Selection must have the power of increasing it. Now take two species A and B, and assume that they are (by any means) half-sterile, i.e., produce half the full number of offspring. Now try and make (by Natural Selection) A and B absolutely sterile when crossed, and you will find how difficult it is. I grant, indeed it is certain, that the degree of the sterility of the individuals of A and B will vary; but any such extra-sterile individuals of, we will say A, if they should hereafter breed with other individuals of A, will bequeath no advantage to their progeny, by which these families will tend to increase in number over other families of A, which are not more sterile when crossed with B. But I do not know that I have made this any clearer than in the chapter in my book. It is a most difficult bit of reasoning, which I have gone over and over again on paper with diagrams. (210/1. This letter appeared in "Life and Letters," III., page 80.)

211. A.R. WALLACE TO CHARLES DARWIN. March 1st, 1868

I beg to enclose what appears to me a demonstration on your own principles, that Natural Selection could produce sterility of hybrids. If it does not convince you, I shall be glad if you will point out where the fallacy lies. I have taken the two cases of a slight sterility overcoming perfect fertility, and of a perfect sterility overcoming a partial fertility,--the beginning and end of the process. You admit that variations in fertility and sterility occur, and I think you will also admit that if I demonstrate that a considerable amount of sterility would be advantageous to a variety, that is sufficient proof that the slightest variation in that direction would be useful also, and would go on accumulating.

1. Let there be a species which has varied into two forms, each adapted to existing conditions (211/1. "Existing conditions," means of course new conditions which have now come into existence. And the "two" being both better adapted than the parent form, means that they are better adapted each to a special environment in the same area--as one to damp, another to dry places; one to woods, another to open grounds, etc., etc., as Darwin had already explained. A.R.W. (1899).) better than the parent form, which they supplant.

2. If these two forms, which are supposed to co-exist in the same district, do not intercross, Natural Selection will accumulate favourable variations, till they become sufficiently well adapted to their conditions of life and form two allied species.

3. But if these two forms freely intercross with each other and produce hybrids which are also quite fertile inter se, then the formation of the two distinct races or species will be retarded or perhaps entirely prevented; for the offspring of the crossed unions will be more vigorous owing to the cross, although less adapted to their conditions of life than either of the pure breeds. (211/2. After "pure breeds," add "because less specialised." A.R.W. (1899).)

4. Now let a partial sterility of some individuals of these two forms arise when they intercross; and as this would probably be due to some special conditions of life, we may fairly suppose it to arise in some definite portion of the area occupied by the two forms.

5. The result is that in this area hybrids will not increase so rapidly as before; and as by the terms of the problem the two pure forms are better suited to the conditions of life than the hybrids, they will tend to supplant the latter altogether whenever the struggle for existence becomes severe.

6. We may fairly suppose, also, that as soon as any sterility appears under natural conditions, it will be accompanied by some disinclination to cross-unions; and this will further diminish the production of hybrids.

7. In the other part of the area, however, where hybridism occurs unchecked, hybrids of various degrees will soon far outnumber the parent or pure form.

8. The first result, then, of a partial sterility of crosses appearing in one part of the area occupied by the two forms, will be, that the GREAT MAJORITY of the individuals will there consist of the pure forms only, while in the rest of the area these will be in a minority,--which is the same as saying, that the new sterile or physiological variety of the two forms will be better suited to the conditions of existence than the remaining portion which has not varied physiologically.

9. But when the struggle for existence becomes severe, that variety which is best adapted to the conditions of existence always supplants that which is imperfectly adapted; therefore by Natural Selection the sterile varieties of the two forms will become established as the only ones.

10. Now let a fresh series of variations in the amount of sterility and in the disinclination to crossed unions occur,--also in certain parts of the area: exactly the same result must recur, and the progeny of this new physiological variety again in time occupy the whole area.

11. There is yet another consideration that supports this view. It seems probable that the variations in amount of sterility would to some extent concur with and perhaps depend upon the structural variations; so that just in proportion as the two forms diverged and became better adapted to the conditions of existence, their sterility would increase. If this were the case, then Natural Selection would act with double strength, and those varieties which were better adapted to survive both structurally and physiologically, would certainly do so. (211/3. The preceding eleven paragraphs are substantially but not verbally identical with the statement of the argument in Mr. Wallace's "Darwinism," 1889. Pages 179, 180, note 1.)

12. Let us now consider the more difficult case of two allied species A, B, in the same area, half the individuals of each (As, Bs) being absolutely sterile, the other half (Af, Bf) being partially fertile: will As, Bs ultimately exterminate Af, Bf?

13. To avoid complication, it must be granted, that between As and Bs no cross-unions take place, while between Af and Bf cross-unions are as frequent as direct unions, though much less fertile. We must also leave out of consideration crosses between As and Af, Bs and Bf, with their various approaches to sterility, as I believe they will not affect the final result, although they will greatly complicate the problem.

14. In the first generation there will result: 1st, The pure progeny of As and Bs; 2nd, The pure progeny of Af and of Bf; and 3rd, The hybrid progeny of Af, Bf.

15. Supposing that, in ordinary years, the increased constitutional vigour of the hybrids exactly counterbalances their imperfect adaptations to conditions, there will be in the second generation, besides these three classes, hybrids of the second degree between the first hybrids and Af and Bf respectively. In succeeding generations there will be hybrids of all degrees, varying between the first hybrids and the almost pure types of Af and Bf.

16. Now, if at first the number of individuals of As, Bs, Af and Bf were equal, and year after year the total number continues stationary, I think it can be proved that, while half will be the pure progeny of As and Bs, the other half will become more and more hybridised, until the whole will be hybrids of various degrees.

17. Now, this hybrid and somewhat intermediate race cannot be so well adapted to the conditions of life as the two pure species, which have been formed by the minute adaptation to conditions through Natural Selection; therefore, in a severe struggle for existence, the hybrids must succumb, especially as, by hypothesis, their fertility would not be so great as that of the two pure species.

18. If we were to take into consideration the unions of As with Af and Bs with Bf, the results would become very complicated, but it must still lead to there being a number of pure forms entirely derived from As and Bs, and of hybrid forms mainly derived from Af and Bf; and the result of the struggle of these two sets of individuals cannot be doubtful.

19. If these arguments are sound, it follows that sterility may be accumulated and increased, and finally made complete by Natural Selection, whether the sterile varieties originate together in a definite portion of the area occupied by the two species, or occur scattered over the whole area. (211/4. The first part of this discussion should be considered alone, as it is both more simple and more important. I now believe that the utility, and therefore the cause of sterility between species, is during the process of differentiation. When species are fully formed, the occasional occurrence of hybrids is of comparatively small importance, and can never be a danger to the existence of the species. A.R.W. (1899).)

P.S.--In answer to the objection as to the unequal sterility of reciprocal crosses ("Variation, etc." Volume II., page 186) I reply that, as far as it went, the sterility of one cross would be advantageous even if the other cross was fertile: and just as characters now co-ordinated may have been separately accumulated by Natural Selection, so the reciprocal crosses may have become sterile one at a time.

212. TO A.R. WALLACE. 4, Chester Place, March 17th, 1868

(212/1. Mr. Darwin had already written a short note to Mr. Wallace expressing a general dissent from his view.)

I do not feel that I shall grapple with the sterility argument till my return home; I have tried once or twice, and it has made my stomach feel as if it had been placed in a vice. Your paper has driven three of my children half mad--one sat up till 12 o'clock over it. My second son, the mathematician, thinks that you have omitted one almost inevitable deduction which apparently would modify the result. He has written out what he thinks, but I have not tried fully to understand him. I suppose that you do not care enough about the subject to like to see what he has written.

LETTER 212A. A.R. WALLACE TO CHARLES DARWIN. Hurstpierpoint, March, 24th [1868].

I return your son's notes with my notes on them. Without going into any details, is not this a strong general argument?

1. A species varies occasionally in two directions, but owing to their free intercrossing the varieties never increase.

2. A change of conditions occurs which threatens the existence of the species; but the two varieties are adapted to the changing conditions, and if accumulated will form two new species adapted to the new conditions.

3. Free crossing, however, renders this impossible, and so the species is in danger of extinction.

4. If sterility would be induced, then the pure races would increase more rapidly, and replace the old species.

5. It is admitted that partial sterility between varieties does occasionally occur. It is admitted [that] the degree of this sterility varies; is it not probable that Natural Selection can accumulate these variations, and thus save the species? If Natural Selection can NOT do this, how do species ever arise, except when a variety is isolated?

Closely allied species in distinct countries being sterile is no difficulty; for either they diverged from a common ancestor in contact, and Natural Selection increased the sterility, or they were isolated, and have varied since: in which case they have been for ages influenced by distinct conditions which may well produce sterility.

If the difficulty of grafting was as great as the difficulty of crossing, and as regular, I admit it would be a most serious objection. But it is not. I believe many distinct species can be grafted, while others less distinct cannot. The regularity with which natural species are sterile together, even when very much alike, I think is an argument in favour of the sterility having been generally produced by Natural Selection for the good of the species.

The other difficulty, of unequal sterility of reciprocal crosses, seems none to me; for it is a step to more complete sterility, and as such would be increased by selection.

213. TO A.R. WALLACE. Down, April 6th [1868]

I have been considering the terrible problem. Let me first say that no man could have more earnestly wished for the success of Natural Selection in regard to sterility than I did; and when I considered a general statement (as in your last note) I always felt sure it could be worked out, but always failed in detail. The cause being, as I believe, that Natural Selection cannot effect what is not good for the individual, including in this term a social community. It would take a volume to discuss all the points, and nothing is so humiliating to me as to agree with a man like you (or Hooker) on the premises and disagree about the result.

I agree with my son's argument and not with the rejoinder. The cause of our difference, I think, is that I look at the number of offspring as an important element (all circumstances remaining the same) in keeping up the average number of individuals within any area. I do not believe that the amount of food by any means is the sole determining cause of number. Lessened fertility is equivalent to a new source of destruction. I believe if in one district a species produced from any cause fewer young, the deficiency would be supplied from surrounding districts. This applies to your Paragraph 5. (213/1. See Letter 211.) If the species produced fewer young from any cause in every district, it would become extinct unless its fertility were augmented through Natural Selection (see H. Spencer).

I demur to probability and almost to possibility of Paragraph 1., as you start with two forms within the same area, which are not mutually sterile, and which yet have supplanted the parent-form.

(Paragraph 6.) I know of no ghost of a fact supporting belief that disinclination to cross accompanies sterility. It cannot hold with plants, or the lower fixed aquatic animals. I saw clearly what an immense aid this would be, but gave it up. Disinclination to cross seems to have been independently acquired, probably by Natural Selection; and I do not see why it would not have sufficed to have prevented incipient species from blending to have simply increased sexual disinclination to cross.

(Paragraph 11.) I demur to a certain extent to amount of sterility and structural dissimilarity necessarily going together, except indirectly and by no means strictly. Look at vars. of pigeons, fowls, and cabbages.

I overlooked the advantage of the half-sterility of reciprocal crosses; yet, perhaps from novelty, I do not feel inclined to admit probability of Natural Selection having done its work so queerly.

I will not discuss the second case of utter sterility, but your assumptions in Paragraph 13 seem to me much too complicated. I cannot believe so universal an attribute as utter sterility between remote species was acquired in so complex a manner. I do not agree with your rejoinder on grafting: I fully admit that it is not so closely restricted as crossing, but this does not seem to me to weaken the case as one of analogy. The incapacity of grafting is likewise an invariable attribute of plants sufficiently remote from each other, and sometimes of plants pretty closely allied.

The difficulty of increasing the sterility through Natural Selection of two already sterile species seems to me best brought home by considering an actual case. The cowslip and primrose are moderately sterile, yet occasionally produce hybrids. Now these hybrids, two or three or a dozen in a whole parish, occupy ground which might have been occupied by either pure species, and no doubt the latter suffer to this small extent. But can you conceive that any individual plants of the primrose and cowslip which happened to be mutually rather more sterile (i.e. which, when crossed, yielded a few less seed) than usual, would profit to such a degree as to increase in number to the ultimate exclusion of the present primrose and cowslip? I cannot.

My son, I am sorry to say, cannot see the full force of your rejoinder in regard to second head of continually augmented sterility. You speak in this rejoinder, and in Paragraph 5, of all the individuals becoming in some slight degree sterile in certain districts: if you were to admit that by continued exposure to these same conditions the sterility would inevitably increase, there would be no need of Natural Selection. But I suspect that the sterility is not caused so much by any particular conditions as by long habituation to conditions of any kind. To speak according to pangenesis, the gemmules of hybrids are not injured, for hybrids propagate freely by buds; but their reproductive organs are somehow affected, so that they cannot accumulate the proper gemmules, in nearly the same manner as the reproductive organs of a pure species become affected when exposed to unnatural conditions.

This is a very ill-expressed and ill-written letter. Do not answer it, unless the spirit urges you. Life is too short for so long a discussion. We shall, I greatly fear, never agree.

214. A.R. WALLACE TO CHARLES DARWIN. Hurstpierpoint, [April?] 8th, 1868

I am sorry you should have given yourself the trouble to answer my ideas on sterility. If you are not convinced, I have little doubt but that I am wrong; and, in fact, I was only half convinced by my own arguments, and I now think there is about an even chance that Natural Selection may or may not be able to accumulate sterility. If my first proposition is modified to the existence of a species and a variety in the same area, it will do just as well for my argument. Such certainly do exist. They are fertile together, and yet each maintains itself tolerably distinct. How can this be, if there is no disinclination to crossing?

My belief certainly is that number of offspring is not so important an element in keeping up population of a species as supply of food and other favourable conditions; because the numbers of a species constantly vary greatly in different parts of its own area, whereas the average number of offspring is not a very variable element.

However, I will say no more, but leave the problem as insoluble, only fearing that it will become a formidable weapon in the hands of the enemies of Natural Selection.

215. TO J.D. HOOKER

(215/1. The following extract from a letter to Sir Joseph Hooker (dated April 3rd, 1868) refers to his Presidential Address for the approaching meeting of the British Association at Norwich.

Some account of Sir Joseph's success is given in the "Life and Letters," III., page 100, also in Huxley's "Life," Volume I., page 297, where Huxley writes to Darwin:--

"We had a capital meeting at Norwich, and dear old Hooker came out in great force, as he always does in emergencies. The only fault was the terrible 'Darwinismus' which spread over the section and crept out when you least expected it, even in Fergusson's lecture on 'Buddhist Temples.' You will have the rare happiness to see your ideas triumphant during your lifetime.

"P.S.--I am going into opposition; I can't stand it.")

Down, April 3rd [1868].

I have been thinking over your Presidential Address; I declare I made myself quite uncomfortable by fancying I had to do it, and feeling myself utterly dumbfounded.

But I do not believe that you will find it so difficult. When you come to Down I shall be very curious to hear what your ideas are on the subject.

Could you make anything out of a history of the great steps in the progress of Botany, as representing the whole of Natural History? Heaven protect you! I suppose there are men to whom such a job would not be so awful as it appears to me...If you had time, you ought to read an article by W. Bagehot in the April number of the "Fortnightly" (215/2. "Physic and Politics," "Fortnightly Review," Volume III., page 452, 1868.), applying Natural Selection to early or prehistoric politics, and, indeed, to late politics,--this you know is your view.

216. A.R. WALLACE TO CHARLES DARWIN. 9, St. Mark's Crescent, N.W., August 16th [1868]

I ought to have written before to thank you for the copies of your papers on Primula and on "Cross-unions of Dimorphic Plants, etc." The latter is particularly interesting and the conclusion most important; but I think it makes the difficulty of how these forms, with their varying degrees of sterility, originated, greater than ever. If "natural selection" could not accumulate varying degrees of sterility for the plant's benefit, then how did sterility ever come to be associated with one cross of a trimorphic plant rather than another? The difficulty seems to be increased by the consideration that the advantage of a cross with a distinct individual is gained just as well by illegitimate as by legitimate unions. By what means, then, did illegitimate unions ever become sterile? It would seem a far simpler way for each plant's pollen to have acquired a prepotency on another individual's stigma over that of the same individual, without the extraordinary complication of three differences of structure and eighteen different unions with varying degrees of sterility!

However, the fact remains an excellent answer to the statement that sterility of hybrids proves the absolute distinctness of the parents.

I have been reading with great pleasure Mr. Bentham's last admirable address (216/1. "Proc. Linn. Soc." 1867-8, page lvii.), in which he so well replies to the gross misstatements of the "Athenaeum;" and also says award in favour of pangenesis. I think we may now congratulate you on having made a valuable convert, whose opinions on the subject, coming so late and being evidently so well considered, will have much weight.

I am going to Norwich on Tuesday to hear Dr. Hooker, who I hope will boldly promulgate "Darwinism" in his address. (216/2. Sir Joseph Hooker's Presidential Address at the British Association Meeting.) Shall we have the pleasure of seeing you there?

I am engaged in negociations about my book.

Hoping you are well and getting on with your next volumes.

(216/3. We are permitted by Mr. Wallace to append the following note as to his more recent views on the question of Natural Selection and sterility:--

"When writing my "Darwinism," and coming again to the consideration of this problem of the effect of Natural Selection in accumulating variations in the amount of sterility between varieties or incipient species twenty years later, I became more convinced, than I was when discussing with Darwin, of the substantial accuracy of my argument. Recently a correspondent who is both a naturalist and a mathematician has pointed out to me a slight error in my calculation at page 183 (which does not, however, materially affect the result), disproving the 'physiological selection' of the late Dr. Romanes, but he can see no fallacy in my argument as to the power of Natural Selection to increase sterility between incipient species, nor, so far as I am aware, has any one shown such fallacy to exist.

"On the other points on which I differed from Mr. Darwin in the foregoing discussion--the effect of high fertility on population of a species, etc.--I still hold the views I then expressed, but it would be out of place to attempt to justify them here."

A.R.W. (1899).)

217. TO C. LYELL. Down, October 4th [1867]

With respect to the points in your note, I may sometimes have expressed myself with ambiguity. At the end of Chapter XXIII., where I say that marked races are not often (you omit "often") produced by changed conditions (217/1. "Hence, although it must be admitted that new conditions of life do sometimes definitely affect organic beings, it may be doubted whether well-marked races have often been produced by the direct action of changed conditions without the aid of selection either by man or nature." ("Animals and Plants," Volume II., page 292, 1868.)), I intended to refer to the direct action of such conditions in causing variation, and not as leading to the preservation or destruction of certain forms. There is as wide a difference in these two respects as between voluntary selection by man and the causes which induce variability. I have somewhere in my book referred to the close connection between Natural Selection and the action of external conditions in the sense which you specify in your note. And in this sense all Natural Selection may be said to depend on changed conditions. In the "Origin" I think I have underrated (and from the cause which you mention) the effects of the direct action of external conditions in producing varieties; but I hope in Chapter XXIII. I have struck as fair a balance as our knowledge permits.

It is wonderful to me that you have patience to read my slips, and I cannot but regret, as they are so imperfect; they must, I think, give you a wrong impression, and had I sternly refused, you would perhaps have thought better of my book. Every single slip is greatly altered, and I hope improved.

With respect to the human ovule, I cannot find dimensions given, though I have often seen the statement. My impression is that it would be just or barely visible if placed on a clear piece of glass. Huxley could answer your question at once.

I have not been well of late, and have made slow progress, but I think my book will be finished by the middle of November.

218. A.R. WALLACE TO CHARLES DARWIN. [End of February, 1868]

I am in the second volume of your book, and I have been astonished at the immense number of interesting facts you have brought together. I read the chapter on pangenesis first, for I could not wait. I can hardly tell you how much I admire it. It is a positive comfort to me to have any feasible explanation of a difficulty that has always been haunting me, and I shall never be able to give it up till a better one supplies its place,--and that I think hardly possible. You have now fairly beaten Spencer on his own ground, for he really offered no solution of the difficulties of the problem. The incomprehensible minuteness and vast numbers of the physiological germs or atoms (which themselves must be compounded of numbers of Spencer's physiological units) is the only difficulty; but that is only on a par with the difficulties in all conceptions of matter, space, motion, force, etc.

As I understood Spencer, his physiological units were identical throughout each species, but slightly different in each different species; but no attempt was made to show how the identical form of the parent or ancestors came to be built up of such units.

219. TO A.R. WALLACE. Down, February 27th [1868]

You cannot well imagine how much I have been pleased by what you say about pangenesis. None of my friends will speak out, except to a certain extent Sir H. Holland, who found it very tough reading, but admits that some view "closely akin to it" will have to be admitted. Hooker, as far as I understand him, which I hardly do at present, seems to think that the hypothesis is little more than saying that organisms have such and such potentialities. What you say exactly and fully expresses my feelings--viz., that it is a relief to have some feasible explanation of the various facts, which can be given up as soon as any better hypothesis is found. It has certainly been an immense relief to my mind; for I have been stumbling over the subject for years, dimly seeing that some relation existed between the various classes of facts. I now hear from H. Spencer that his views quoted in my footnote refer to something quite distinct, as you seem to have perceived. (219/1. This letter is published in "Life and Letters," III., page 79.)

220. A.R. WALLACE TO CHARLES DARWIN. Hurstpierpoint, March 1st, 1868

...Sir C. Lyell spoke to me as if he has greatly admired pangenesis. I am very glad H. Spencer at once acknowledges that his view was something quite distinct from yours. Although, as you know, I am a great admirer of his, I feel how completely his view failed to go to the root of the matter, as yours does. His explained nothing, though he was evidently struggling hard to find an explanation. Yours, as far as I can see, explains everything in growth and reproduction--though, of course, the mystery of life and consciousness remains as great as ever.

Parts of the chapter on pangenesis I found hard reading, and have not quite mastered yet, and there are also throughout the discussions in Volume II. many bits of hard reading, on minute points which we, who have not worked experimentally at cultivation and crossing, as you have done, can hardly see the importance of, or their bearing on the general question.

If I am asked, I may perhaps write an article on the book for some periodical, and, if so, shall do what I can to make "Pangenesis" appreciated...

(220/1. In "Nature," May 25th, 1871, page 69, appeared a letter on pangenesis from Mr. A.C. Ranyard, dealing with the difficulty that the "sexual elements produced upon the scion" have not been shown to be affected by the stock. Mr. Darwin, in an annotated copy of this letter, disputes the accuracy of the statement, but adds: "THE BEST OBJECTION YET RAISED." He seems not to have used Mr. Ranyard's remarks in the 2nd edition of the "Variation of Animals and Plants," 1875.)

221. TO J.D. HOOKER. Down, May 21st [1868]

I know that you have been overworking yourself, and that makes you think that you are doing nothing in science. If this is the case (which I do not believe), your intellect has all run to letter-writing, for I never in all my life received a pleasanter one than your last. It greatly amused us all. How dreadfully severe you are on the Duke (221/1. The late Duke of Argyll, whose "Reign of Law" Sir J.D. Hooker had been reading.): I really think too severe, but then I am no fair judge, for a Duke, in my eyes, is no common mortal, and not to be judged by common rules! I pity you from the bottom of my soul about the address (221/2. Sir Joseph was President of the British Association at Norwich in 1868: see "Life and Letters," III., page 100. The reference to "Insular Floras" is to Sir Joseph's lecture at the Nottingham meeting of the British Association in 1866: see "Life and Letters," III., page 47.): it makes my flesh creep; but when I pitied you to Huxley, he would not join at all, and would only say that you did and delivered your Insular Flora lecture so admirably in every way that he would not bestow any pity on you. He felt certain that you would keep your head high up. Nevertheless, I wish to God it was all over for your sake. I think, from several long talks, that Huxley will give an excellent and original lecture on Geograph. Distrib. of birds. I have been working very hard--too hard of late--on Sexual Selection, which turns out a gigantic subject; and almost every day new subjects turn up requiring investigation and leading to endless letters and searches through books. I am bothered, also, with heaps of foolish letters on all sorts of subjects, but I am much interested in my subject, and sometimes see gleams of light. All my other letters have prevented me indulging myself in writing to you; but I suddenly found the locust grass (221/3. No doubt the plants raised from seeds taken from locust dung sent by Mr. Weale from South Africa. The case is mentioned in the fifth edition of the "Origin," published in 1869, page 439.) yesterday in flower, and had to despatch it at once. I suppose some of your assistants will be able to make the genus out without great trouble. I have done little in experiment of late, but I find that mignonette is absolutely sterile with pollen from the same plant. Any one who saw stamen after stamen bending upwards and shedding pollen over the stigmas of the same flower would declare that the structure was an admirable contrivance for self-fertilisation. How utterly mysterious it is that there should be some difference in ovules and contents of pollen-grains (for the tubes penetrate own stigma) causing fertilisation when these are taken from any two distinct plants, and invariably leading to impotence when taken from the same plant! By Jove, even Pan. (221/4. Pangenesis.) won't explain this. It is a comfort to me to think that you will be surely haunted on your death-bed for not honouring the great god Pan. I am quite delighted at what you say about my book, and about Bentham; when writing it, I was much interested in some parts, but latterly I thought quite as poorly of it as even the "Athenaeum." It ought to be read abroad for the sake of the booksellers, for five editions have come or are coming out abroad! I am ashamed to say that I have read only the organic part of Lyell, and I admire all that I have read as much as you. It is a comfort to know that possibly when one is seventy years old one's brain may be good for work. It drives me mad, and I know it does you too, that one has no time for reading anything beyond what must be read: my room is encumbered with unread books. I agree about Wallace's wonderful cleverness, but he is not cautious enough in my opinion. I find I must (and I always distrust myself when I differ from him) separate rather widely from him all about birds' nests and protection; he is riding that hobby to death. I never read anything so miserable as Andrew Murray's criticism on Wallace in the last number of his Journal. (221/5. See "Journal of Travel and Natural History," Volume I., No. 3, page 137, London, 1868, for Andrew Murray's "Reply to Mr. Wallace's Theory of Birds' Nests," which appeared in the same volume, page 73. The "Journal" came to an end after the publication of one volume for 1867-8.) I believe this Journal will die, and I shall not cry: what a contrast with the old "Natural History Review."

222. TO J.D. HOOKER. Freshwater, Isle of Wight, July 28th [1868]

I am glad to hear that you are going (222/1. In his Presidential Address at Norwich.) to touch on the statement that the belief in Natural Selection is passing away. I do not suppose that even the "Athenaeum" would pretend that the belief in the common descent of species is passing away, and this is the more important point. This now almost universal belief in the evolution (somehow) of species, I think may be fairly attributed in large part to the "Origin." It would be well for you to look at the short Introduction of Owen's "Anat. of Invertebrates," and see how fully he admits the descent of species.

Of the "Origin," four English editions, one or two American, two French, two German, one Dutch, one Italian, and several (as I was told) Russian editions. The translations of my book on "Variation under Domestication" are the results of the "Origin;" and of these two English, one American, one German, one French, one Italian, and one Russian have appeared, or will soon appear. Ernst Hackel wrote to me a week or two ago, that new discussions and reviews of the "Origin" are continually still coming out in Germany, where the interest on the subject certainly does not diminish. I have seen some of these discussions, and they are good ones. I apprehend that the interest on the subject has not died out in North America, from observing in Professor and Mrs. Agassiz's Book on Brazil how exceedingly anxious he is to destroy me. In regard to this country, every one can judge for himself, but you would not say interest was dying out if you were to look at the last number of the "Anthropological Review," in which I am incessantly sneered at. I think Lyell's "Principles" will produce a considerable effect. I hope I have given you the sort of information which you want. My head is rather unsteady, which makes my handwriting worse than usual.

If you argue about the non-acceptance of Natural Selection, it seems to me a very striking fact that the Newtonian theory of gravitation, which seems to every one now so certain and plain, was rejected by a man so extraordinarily able as Leibnitz. The truth will not penetrate a preoccupied mind.

Wallace (222/2. Wallace, "Westminster Review," July, 1867. The article begins: "There is no more convincing proof of the truth of a comprehensive theory, than its power of absorbing and finding a place for new facts, and its capability of interpreting phenomena, which had been previously looked upon as unaccountable anomalies..." Mr. Wallace illustrates his statement that "a false theory will never stand this test," by Edward Forbes' "polarity" speculations (see page 84 of the present volume) and Macleay's "Circular" and "Quinarian System" published in his "Horae Entomologicae," 1821, and developed by Swainson in the natural history volumes of "Lardner's Cabinet Cyclopaedia." Mr. Wallace says that a "considerable number of well-known naturalists either spoke approvingly of it, or advocated similar principles, and for a good many years it was decidedly in the ascendant...yet it quite died out in a few short years, its very existence is now a matter of history, and so rapid was its fall that...Swainson, perhaps, lived to be the last man who believed in it. Such is the course of a false theory. That of a true one is very different, as may be well seen by the progress of opinion on the subject of Natural Selection."

Here, (page 3) follows a passage on the overwhelming importance of Natural Selection, underlined with apparent approval in Mr. Darwin's copy of the review.), in the "Westminster Review," in an article on Protection has a good passage, contrasting the success of Natural Selection and its growth with the comprehension of new classes of facts (222/3. This rather obscure phrase may be rendered: "its power of growth by the absorption of new facts."), with false theories, such as the Quinarian Theory, and that of Polarity, by poor Forbes, both of which were promulgated with high advantages and the first temporarily accepted.

223. TO G.H. LEWES

(223/1. The following is printed from a draft letter inscribed by Mr. Darwin "Against organs having been formed by direct action of medium in distinct organisms. Chiefly luminous and electric organs and thorns." The draft is carelessly written, and all but illegible.)

August 7th, 1868.

If you mean that in distinct animals, parts or organs, such for instance as the luminous organs of insects or the electric organs of fishes, are wholly the result of the external and internal conditions to which the organs have been subjected, in so direct and inevitable a manner that they could be developed whether of use or not to their possessor, I cannot admit [your view]. I could almost as soon admit that the whole structure of, for instance, a woodpecker, had thus originated; and that there should be so close a relation between structure and external circumstances which cannot directly affect the structure seems to me to [be] inadmissible. Such organs as those above specified seem to me much too complex and generally too well co-ordinated with the whole organisation, for the admission that they result from conditions independently of Natural Selection. The impression which I have taken, studying nature, is strong, that in all cases, if we could collect all the forms which have ever lived, we should have a close gradation from some most simple beginning. If similar conditions sufficed, without the aid of Natural Selection, to give similar parts or organs, independently of blood relationship, I doubt much whether we should have that striking harmony between the affinities, embryological development, geographical distribution, and geological succession of all allied organisms. We should be much more puzzled than we now are how to class, in a natural method, many forms. It is puzzling enough to distinguish between resemblance due to descent and to adaptation; but (fortunately for naturalists), owing to the strong power of inheritance, and to excessively complex causes and laws of variability, when the same end or object has been gained, somewhat different parts have generally been modified, and modified in a different manner, so that the resemblances due to descent and adaptation can commonly be distinguished. I should just like to add, that we may understand each other, how I suppose the luminous organs of insects, for instance, to have been developed; but I depend on conjectures, for so few luminous insects exist that we have no means of judging, by the preservation to the present day of slightly modified forms, of the probable gradations through which the organs have passed. Moreover, we do not know of what use these organs are. We see that the tissues of many animals, [as] certain centipedes in England, are liable, under unknown conditions of food, temperature, etc., to become occasionally luminous; just like the [illegible]: such luminosity having been advantageous to certain insects, the tissues, I suppose, become specialised for this purpose in an intensified degree; in certain insects in one part, in other insects in other parts of the body. Hence I believe that if all extinct insect-forms could be collected, we should have gradations from the Elateridae, with their highly and constantly luminous thoraxes, and from the Lampyridae, with their highly luminous abdomens, to some ancient insects occasionally luminous like the centipede.

I do not know, but suppose that the microscopical structure of the luminous organs in the most different insects is nearly the same; and I should attribute to inheritance from a common progenitor, the similarity of the tissues, which under similar conditions, allowed them to vary in the same manner, and thus, through Natural Selection for the same general purpose, to arrive at the same result. Mutatis mutandis, I should apply the same doctrine to the electric organs of fishes; but here I have to make, in my own mind, the violent assumption that some ancient fish was slightly electrical without having any special organs for the purpose. It has been stated on evidence, not trustworthy, that certain reptiles are electrical. It is, moreover, possible that the so-called electric organs, whilst in a condition not highly developed, may have subserved some distinct function: at least, I think, Matteucci could detect no pure electricity in certain fishes provided with the proper organs. In one of your letters you alluded to nails, claws, hoofs, etc. From their perfect coadaptation with the whole rest of the organisation, I cannot admit that they would have been formed by the direct action of the conditions of life. H. Spencer's view that they were first developed from indurated skin, the result of pressure on the extremities, seems to me probable.

In regard to thorns and spines I suppose that stunted and [illegible] hardened processes were primarily left by the abortion of various appendages, but I must believe that their extreme sharpness and hardness is the result of fluctuating variability and "the survival of the fittest." The precise form, curvature and colour of the thorns I freely admit to be the result of the laws of growth of each particular plant, or of their conditions, internal and external. It would be an astounding fact if any varying plant suddenly produced, without the aid of reversion or selection, perfect thorns. That Natural Selection would tend to produce the most formidable thorns will be admitted by every one who has observed the distribution in South America and Africa (vide Livingstone) of thorn-bearing plants, for they always appear where the bushes grow isolated and are exposed to the attacks of mammals. Even in England it has been noticed that all spine-bearing and sting-bearing plants are palatable to quadrupeds, when the thorns are crushed. With respect to the Malayan climbing Palm, what I meant to express is that the admirable hooks were perhaps not first developed for climbing; but having been developed for protection were subsequently used, and perhaps further modified for climbing.

224. TO J.D. HOOKER. Down, September 8th [1868]

About the "Pall Mall." (224/1. "Pall Mall Gazette," August 22nd, 1868. In an article headed "Dr. Hooker on Religion and Science," and referring to the British Association address, the writer objects to any supposed opposition between religion and science. "Religion," he says, "is your opinion upon one set of subjects, science your opinion upon another set of subjects." But he forgets that on one side we have opinions assumed to be revealed truths; and this is a condition which either results in the further opinion that those who bring forward irreconcilable facts are more or less wicked, or in a change of front on the religious side, by which theological opinion "shifts its ground to meet the requirements of every new fact that science establishes, and every old error that science exposes" (Dr. Hooker as quoted by the "Pall Mall"). If theologians had been in the habit of recognising that, in the words of the "Pall Mall" writer, "Science is a general name for human knowledge in its most definite and general shape, whatever may be the object of that knowledge," probably Sir Joseph Hooker's remarks would never have been made.) I do not agree that the article was at all right; it struck me as monstrous (and answered on the spot by the "Morning Advertiser") that religion did not attack science. When, however, I say not at all right, I am not sure whether it would not be wisest for scientific men quite to ignore the whole subject of religion. Goldwin Smith, who has been lunching here, coming with the Nortons (son of Professor Norton and friend of Asa Gray), who have taken for four months Keston Rectory, was strongly of opinion it was a mistake. Several persons have spoken strongly to me as very much admiring your address. For chance of you caring to see yourself in a French dress, I send a journal; also with a weak article by Agassiz on Geographical Distribution. Berkeley has sent me his address (224/2. The Rev. M.J. Berkeley was President of Section D at Norwich in 1868.), so I have had a fair excuse for writing to him. I differ from you: I could hardly bear to shake hands with the "Sugar of Lead" (224/3. "You know Mrs. Carlyle said that Owen's sweetness reminded her of sugar of lead." (Huxley to Tyndall, May 13th, 1887: Huxley's "Life," II., page 167.), which I never heard before: it is capital. I am so very glad you will come here with Asa Gray, as if I am bad he will not be dull. We shall ask the Nortons to come to dinner. On Saturday, Wallace (and probably Mrs. W.), J. Jenner Weir (a very good man), and Blyth, and I fear not Bates, are coming to stay the Sunday. The thought makes me rather nervous; but I shall enjoy it immensely if it does not kill me. How I wish it was possible for you to be here!

225. TO M.J. BERKELEY. Down, September 7th, 1868

I am very much obliged to you for having sent me your address (225/1. Address to Section D of the British Association. ("Brit. Assoc. Report," Norwich meeting, 1868, page 83.))...for I thus gain a fair excuse for troubling you with this note to thank you for your most kind and extremely honourable notice of my works.

When I tell you that ever since I was an undergraduate at Cambridge I have felt towards you the most unfeigned respect, from all that I continually heard from poor dear Henslow and others of your great knowledge and original researches, you will believe me when I say that I have rarely in my life been more gratified than by reading your address; though I feel that you speak much too strongly of what I have done. Your notice of pangenesis (225/3. "It would be unpardonable to finish these somewhat desultory remarks without adverting to one of the most interesting subjects of the day,--the Darwinian doctrine of pangenesis...Like everything which comes from the pen of a writer whom I have no hesitation, so far as my judgment goes, in considering as by far the greatest observer of our age, whatever may be thought of his theories when carried out to their extreme results, the subject demands a careful and impartial consideration." (Berkeley, page 86.)) has particularly pleased me, for it has been generally neglected or disliked by my friends; yet I fully expect that it will some day be more successful. I believe I quite agree with you in the manner in which the cast-off atoms or so-called gemmules probably act (225/4. "Assuming the general truth of the theory that molecules endowed with certain attributes are cast off by the component cells of such infinitesimal minuteness as to be capable of circulating with the fluids, and in the end to be present in the unimpregnated embryo-cell and spermatozoid...it seems to me far more probable that they should be capable under favourable circumstances of exercising an influence analogous to that which is exercised by the contents of the pollen-tube or spermatozoid on the embryo-sac or ovum, than that these particles should be themselves developed into cells" (Berkeley, page 87).): I have never supposed that they were developed into free cells, but that they penetrated other nascent cells and modified their subsequent development. This process I have actually compared with ordinary fertilisation. The cells thus modified, I suppose cast off in their turn modified gemmules, which again combine with other nascent cells, and so on. But I must not trouble you any further.

226. TO AUGUST WEISMANN. Down, October 22nd, 1868

I am very much obliged for your kind letter, and I have waited for a week before answering it in hopes of receiving the "kleine Schrift" (226/1. The "kleine Schrift" is "Ueber die Berechtigung der Darwin'schen Theorie," Leipzig, 1868. The "Anhang" is "Ueber den Einfluss der Wanderung und raumlichen Isolirung auf die Artbilding.") to which you allude; but I fear it is lost, which I am much surprised at, as I have seldom failed to receive anything sent by the post.

As I do not know the title, and cannot order a copy, I should be very much obliged if you can spare another.

I am delighted that you, with whose name I am familiar, should approve of my work. I entirely agree with what you say about each species varying according to its own peculiar laws; but at the same time it must, I think, be admitted that the variations of most species have in the lapse of ages been extremely diversified, for I do not see how it can be otherwise explained that so many forms have acquired analogous structures for the same general object, independently of descent. I am very glad to hear that you have been arguing against Nageli's law of perfectibility, which seems to me superfluous. Others hold similar views, but none of them define what this "perfection" is which cannot be gradually attained through Natural Selection. I thought M. Wagner's first pamphlet (226/2. Wagner's first essay, "Die Darwin'sche Theorie und das Migrationsgesetz," 1868, is a separately published pamphlet of 62 pages. In the preface the author states that it is a fuller version of a paper read before the Royal Academy of Science at Munich in March 1868. We are not able to say which of Wagner's writings is referred to as the second pamphlet; his second well-known essay, "Ueber den Einfluss der Geogr. Isolirung," etc., is of later date, viz., 1870.) (for I have not yet had time to read the second) very good and interesting; but I think that he greatly overrates the necessity for emigration and isolation. I doubt whether he has reflected on what must occur when his forms colonise a new country, unless they vary during the very first generation; nor does he attach, I think, sufficient weight to the cases of what I have called unconscious selection by man: in these cases races are modified by the preservation of the best and the destruction of the worst, without any isolation.

I sympathise with you most sincerely on the state of your eyesight: it is indeed the most fearful evil which can happen to any one who, like yourself, is earnestly attached to the pursuit of natural knowledge.

227. TO F. MULLER. Down, March 18th [1869]

Since I wrote a few days ago and sent off three copies of your book, I have read the English translation (227/1. "Facts and Arguments for Darwin." See "Life and Letters," III., page 37.), and cannot deny myself the pleasure of once again expressing to you my warm admiration. I might, but will not, repeat my thanks for the very honourable manner in which you often mention my name; but I can truly say that I look at the publication of your essay as one of the greatest honours ever conferred on me. Nothing can be more profound and striking than your observations on development and classification. I am very glad that you have added your justification in regard to the metamorphoses of insects; for your conclusion now seems in the highest degree probable. (227/2. See "Facts and Arguments for Darwin," page 119 (note), where F. Muller gives his reasons for the belief that the "complete metamorphosis" of insects was not a character of the form from which insects have sprung: his argument largely depends on considerations drawn from the study of the neuroptera.) I have re-read many parts, especially that on cirripedes, with the liveliest interest. I had almost forgotten your discussion on the retrograde development of the Rhizocephala. What an admirable illustration it affords of my whole doctrine! A man must indeed be a bigot in favour of separate acts of creation if he is not staggered after reading your essay; but I fear that it is too deep for English readers, except for a select few.

228. TO A.R. WALLACE. March 27th [1869]

I have lately (i.e., in new edition of the "Origin") (228/1. Fifth edition, 1869, pages 150-57.) been moderating my zeal, and attributing much more to mere useless variability. I did think I would send you the sheet, but I daresay you would not care to see it, in which I discuss Nageli's Essay on Natural Selection not affecting characters of no functional importance, and which yet are of high classificatory importance. Hooker is pretty well satisfied with what I have said on this head.

229. TO J.D. HOOKER. Caerdeon, Barmouth, North Wales, July 24th [1869]

We shall be at home this day week, taking two days on the journey, and right glad I shall be. The whole has been a failure to me, but much enjoyment to the young...My wife has ailed a good deal nearly all the time; so that I loathe the place, with all its beauty. I was glad to hear what you thought of F. Muller, and I agree wholly with you. Your letter came at the nick of time, for I was writing on the very day to Muller, and I passed on your approbation of Chaps. X. and XI. Some time I should like to borrow the "Transactions of the New Zealand Institute," so as to read Colenso's article. (229/1. Colenso, "On the Maori Races of New Zealand." "N.Z. Inst. Trans." 1868, Pt. 3.) You must read Huxley v. Comte (229/2. "The Scientific Aspects of Positivism." "Fortnightly Review," 1869, page 652, and "Lay Sermons," 1870, page 162. This was a reply to Mr. Congreve's article, "Mr. Huxley on M. Comte," published in the April number of the "Fortnightly," page 407, which had been written in criticism of Huxley's article in the February number of the "Fortnightly," page 128, "On the Physical Basis of Life."); he never wrote anything so clever before, and has smashed everybody right and left in grand style. I had a vague wish to read Comte, and so had George, but he has entirely cured us of any such vain wish.

There is another article (229/3. "North British Review," Volume 50, 1869: "Geological Time," page 406. The papers reviewed are Sir William Thomson, "Trans. R. Soc. Edin." 1862; "Phil. Mag." 1863; Thomson and Tait, "Natural Philosophy," Volume I., App. D; Sir W. Thomson, "Proc. R. Soc. Edin." 1865; "Trans. Geol. Soc. Glasgow," 1868 and 1869; "Macmillan's Mag." 1862; Prof. Huxley, Presidential Address, "Geol. Soc. London," February, 1869; Dr. Hooker, Presidential Address, "Brit. Assoc." Norwich, 1868. Also the review on the "Origin" in the "North British Review," 1867, by Fleeming Jenkin, and an article in the "Pall Mall Gazette," May 3rd, 1869. The author treats the last-named with contempt as the work of an anonymous journalist, apparently unconscious of his own similar position.) just come out in last "North British," by some great mathematician, which is admirably done; he has a severe fling at you (229/4. The author of the "North British" article appears to us, at page 408, to misunderstand or misinterpret Sir J.D. Hooker's parable on "underpinning." See "Life and Letters," III., page 101 (note). Sir Joseph is attacked with quite unnecessary vehemence on another point at page 413.), but the article is directed against Huxley and for Thomson. This review shows me--not that I required being shown--how devilish a clever fellow Huxley is, for the reviewer cannot help admiring his abilities. There are some good specimens of mathematical arrogance in the review, and incidentally he shows how often astronomers have arrived at conclusions which are now seen to be mistaken; so that geologists might truly answer that we must be slow in admitting your conclusions. Nevertheless, all uniformitarians had better at once cry "peccavi,"--not but what I feel a conviction that the world will be found rather older than Thomson makes it, and far older than the reviewer makes it. I am glad I have faced and admitted the difficulty in the last edition of the "Origin," of which I suppose you received, according to order, a copy.

230. TO J.D. HOOKER. Down, August 7th [1869]

There never was such a good man as you for telling me things which I like to hear. I am not at all surprised that Hallett has found some varieties of wheat could not be improved in certain desirable qualities as quickly as at first. All experience shows this with animals; but it would, I think, be rash to assume, judging from actual experience, that a little more improvement could not be got in the course of a century, and theoretically very improbable that after a few thousands [of years] rest there would not be a start in the same line of variation. What astonishes me as against experience, and what I cannot believe, is that varieties already improved or modified do not vary in other respects. I think he must have generalised from two or three spontaneously fixed varieties. Even in seedlings from the same capsule some vary much more than others; so it is with sub-varieties and varieties. (230/1. In a letter of August 13th, 1869, Sir J.D. Hooker wrote correcting Mr. Darwin's impression: "I did not mean to imply that Hallett affirmed that all variation stopped--far from it: he maintained the contrary, but if I understand him aright, he soon arrives at a point beyond which any further accumulation in the direction sought is so small and so slow that practically a fixity of type (not absolute fixity, however) is the result.")

It is a grand fact about Anoplotherium (230/2. This perhaps refers to the existence of Anoplotherium in the S. American Eocene formation: it is one of the points in which the fauna of S. America resembles Europe rather than N. America. (See Wallace "Geographical Distribution," I., page 148.)), and shows how even terrestrial quadrupeds had time formerly to spread to very distinct regions. At each epoch the world tends to get peopled pretty uniformly, which is a blessing for Geology.

The article in "N. British Review" (230/3. See Letter 229.) is well worth reading scientifically; George D. and Erasmus were delighted with it. How the author does hit! It was a euphuism to speak of a fling at you: it was a kick. He is very unfair to Huxley, and accuses him of "quibbling," etc.; yet the author cannot help admiring him extremely. I know I felt very small when I finished the article. You will be amused to observe that geologists have all been misled by Playfair, who was misled by two of the greatest mathematicians! And there are other such cases; so we could turn round and show your reviewer how cautious geologists ought to be in trusting mathematicians.

There is another excellent original article, I feel sure by McClennan, on Primeval Man, well worth reading.

I do not quite agree about Sabine: he is unlike every other soldier or sailor I ever heard of if he would not put his second leg into the tomb with more satisfaction as K.C.B. than as a simple man. I quite agree that the Government ought to have made him long ago, but what does the Government know or care for Science? So much for your splenditious letter.

231. TO J.D. HOOKER. Down, August 14th [1869?]

I write one line to tell you that you are a real good man to propose coming here for a Sunday after Exeter. Do keep to this good intention...I am sure Exeter and your other visit will do you good. I often wonder how you stand all your multifarious work.

I quite agree about the folly of the endless subscriptions for dead men; but Faraday is an exception, and if you will pay three guineas for me, it will save me some trouble; but it will be best to enclose a cheque, which, as you will see, must be endorsed. If you read the "North British Review," you will like to know that George has convinced me, from correspondence in style, and spirit, that the article is by Tait, the co-worker with Thomson.

I was much surprised at the leaves of Drosophyllum being always rolled backwards at their tips, but did not know that it was a unique character.

(PLATE: SIR J.D. HOOKER, 1870? From a photograph by Wallich.)

232. TO J.D. HOOKER. Down, November 13th [1869]

I heard yesterday from a relation who had seen in a newspaper that you were C.B. I must write one line to say "Hurrah," though I wish it had been K.C.B., as it assuredly ought to have been; but I suppose they look at K.C.B. before C.B. as a dukedom before an earldom.

We had a very successful week in London, and I was unusually well and saw a good many persons, which, when well, is a great pleasure to me. I had a jolly talk with Huxley, amongst others. And now I am at the same work as before, and shall be for another two months--namely, putting ugly sentences rather straighter; and I am sick of the work, and, as the subject is all on sexual selection, I am weary of everlasting males and females, cocks and hens.

It is a shame to bother you, but I should like some time to hear about the C.B. affair.

I have read one or two interesting brochures lately--viz., Stirling the Hegelian versus Huxley and protoplasm; Tylor in "Journal of Royal Institute" on the survivals of old thought in modern civilisation.

Farewell. I am as dull as a duck, both male and female.

To Dr. Hooker, C.B., F.R.S.

Dr. Hooker, K.C.B. (This looks better).

P.S. I hear a good account of Bentham's last address (232/1. Presidential Address, chiefly on Geographical Distribution, delivered before the "Linn. Soc." May 24th, 1869.), which I am now going to read.

I find that I have blundered about Bentham's address. Lyell was speaking about one that I read some months ago; but I read half of it again last night, and shall finish it. Some passages are either new or were not studied enough by me before. It strikes me as admirable, as it did on the first reading, though I differ in some few points.

Such an address is worth its weight in gold, I should think, in making converts to our views. Lyell tells me that Bunbury has been wonderfully impressed with it, and he never before thought anything of our views on evolution.

P.S. (2). I have just read, and like very much, your review of Schimper. (232/2. A review of Schimper's "Traite de Paleontologie Vegetale," the first portion of which was published in 1869. "Nature," November 11th, 1869, page 48.)

233. TO J.D. HOOKER. Down, November 19th [1869]

Thank you much for telling me all about the C.B., for I much wished to hear. It pleases me extremely that the Government have done this much; and as the K.C.B.'s are limited in number (which I did not know), I excuse it. I will not mention what you have told me to any one, as it would be Murchisonian. But what a shame it is to use this expression, for I fully believe that Murchison would take any trouble to get any token of honour for any man of science.

I like all scientific periodicals, including poor "Scientific Opinion," and I think higher than you do of "Nature." Lord, what a rhapsody that was of Goethe, but how well translated; it seemed to me, as I told Huxley, as if written by the maddest English scholar. It is poetry, and can I say anything more severe? The last number of the "Academy" was splendid, and I hope it will soon come out fortnightly. I wish "Nature" would search more carefully all foreign journals and transactions.

I am now reading a German thick pamphlet (233/1. "Die Abhangigheit der Pflanzengestalt von Klima und Boden. Ein Beitrag zur Lehre von der Enstehung und Verbreitung der Arten, etc." Festschrift zur 43 Versammlung Deutscher Naturforscher und Aertze in Innsbruck (Innsbruck, 1869).) by Kerner on Tubocytisus; if you come across it, look at the map of the distribution of the eighteen quasi-species, and at the genealogical tree. If the latter, as the author says, was constructed solely from the affinities of the forms, then the distribution is wonderfully interesting; we may see the very steps of the formation of a species. If you study the genealogical tree and map, you will almost understand the book. The two old parent connecting links just keep alive in two or three areas; then we have four widely extended species, their descendants; and from them little groups of newer descendants inhabiting rather small areas...

234. TO CAMILLE DARESTE. Down, November 20th, 1869

Dear Sir,

I am glad that you are a candidate for the Chair of Physiology in Paris. As you are aware from my published works, I have always considered your investigations on the production of monstrosities as full of interest. No subject is at the present time more important, as far as my judgment goes, than the ascertaining by experiment how far structure can be modified by the direct action of changed conditions; and you have thrown much light on this subject.

I observe that several naturalists in various parts of Europe have lately maintained that it is now of the highest interest for science to endeavour to lessen, as far as possible, our profound ignorance on the cause of each individual variation; and, as Is. Geoffroy St. Hilaire long ago remarked, monstrosities cannot be separated by any distinct line from slighter variations.

With my best wishes for your success in obtaining the Professorship, and with sincere respect.

I have the honour to remain, dear sir, Yours faithfully, CHARLES DARWIN.

235. TO J. JENNER WEIR. Down, March 17th [1870]

It is my decided opinion that you ought to send an account to some scientific society, and I think to the Royal Society. (235/1. Mr. Jenner Weir's case is given in "Animals and Plants," Edition II., Volume I., page 435, and does not appear to have been published elsewhere. The facts are briefly that a horse, the offspring of a mare of Lord Mostyn's, which had previously borne a foal by a quagga, showed a number of quagga-like characters, such as stripes, low-growing mane, and elongated hoofs. The passage in "Animals and Plants," to which he directs Mr. Weir's attention in reference to Carpenter's objection, is in Edition I., Volume I., page 405: "It is a most improbable hypothesis that the mere blood of one individual should affect the reproductive organs of another individual in such a manner as to modify the subsequent offspring. The analogy from the direct action of foreign pollen on the ovarium and seed-coats of the mother plant strongly supports the belief that the male element acts directly on the reproductive organs of the female, wonderful as is this action, and not through the intervention of the crossed embryo." For references to Mr. Galton's experiments on transfusion of blood, see Letter 273.) I would communicate it if you so decide. You might give as a preliminary reason the publication in the "Transactions" of the celebrated Morton case and the pig case by Mr. Giles. You might also allude to the evident physiological importance of such facts as bearing on the theory of generation. Whether it would be prudent to allude to despised pangenesis I cannot say, but I fully believe pangenesis will have its successful day. Pray ascertain carefully the colour of the dam and sire. See about duns in my book ["Animals and Plants"], Volume I., page 55. The extension of the mane and form of hoofs are grand new facts. Is the hair of your horse at all curly? for [an] observed case [is] given by me (Volume II., page 325) from Azara of correlation of forms of hoof with curly hairs. See also in my book (Volume I., page 55; Volume II., page 41) how exceedingly rare stripes are on the faces of horses in England. Give the age of your horse.

You are aware that Dr. Carpenter and others have tried to account for the effects of a first impregnation from the influence of the blood of the crossed embryo; but with physiologists who believe that the reproductive elements are actually formed by the reproductive glands, this view is inconsistent. Pray look at what I have said in "Domestic Animals" (Volume I., pages 402-5) against this doctrine. It seems to me more probable that the gemmules affect the ovaria alone. I remember formerly speculating, like you, on the assertion that wives grow like their husbands; but how impossible to eliminate effects of imitation and same habits of life, etc. Your letter has interested me profoundly.

P.S.--Since publishing I have heard of additional cases--a very good one in regard to Westphalian pigs crossed by English boar, and all subsequent offspring affected, given in "Illust. Landwirth-Zeitung," 1868, page 143.

I have shown that mules are often striped, though neither parent may be striped,--due to ancient reversion. Now, Fritz Muller writes to me from S. Brazil: "I have been assured, by persons who certainly never had heard of Lord Morton's mare, that mares which have borne hybrids to an ass are particularly liable to produce afterwards striped ass-colts." So a previous fertilisation apparently gives to the subsequent offspring a tendency to certain characters, as well as characters actually possessed by the first male.

In the reprint (not called a second edition) of my "Domestic Animals" I give a good additional case of subsequent progeny of hairless dog being hairy from effects of first impregnation.

P.S. 2nd. The suggestion, no doubt, is superfluous, but you ought, I think, to measure extension of mane beyond a line joining front or back of ears, and compare with horse. Also the measure (and give comparison with horse), length, breadth, and depth of hoofs.

236. TO J.D. HOOKER. Down, July 12th [1870]

Your conclusion that all speculation about preordination is idle waste of time is the only wise one; but how difficult it is not to speculate! My theology is a simple muddle; I cannot look at the universe as the result of blind chance, yet I can see no evidence of beneficent design or indeed of design of any kind, in the details. As for each variation that has ever occurred having been preordained for a special end, I can no more believe in it than that the spot on which each drop of rain falls has been specially ordained.

Spontaneous generation seems almost as great a puzzle as preordination. I cannot persuade myself that such a multiplicity of organisms can have been produced, like crystals, in Bastian's (236/1. On September 2nd, 1872, Mr. Darwin wrote to Mr. Wallace, in reference to the latter's review of "The Beginnings of Life," by H.C. Bastian (1872), in "Nature," 1872, pages 284-99: "At present I should prefer any mad hypothesis, such as that every disintegrated molecule of the lowest forms can reproduce the parent-form; and that these molecules are universally distributed, and that they do not lose their vital power until heated to such a temperature that they decompose like dead organic particles.") solutions of the same kind. I am astonished that, as yet, I have met with no allusion to Wyman's positive statement (236/2. "Observations and Experiments on Living Organisms in Heated Water," by Jeffries Wyman, Prof. of Anatomy, Harvard Coll. ("Amer. Journ. Sci." XLIV., 1867, page 152.) Solutions of organic matter in hermetically sealed flasks were immersed in boiling water for various periods. "No infusoria of any kind appeared if the boiling was prolonged beyond a period of five hours.") that if the solutions are boiled for five hours no organisms appear; yet, if my memory serves me, the solutions when opened to air immediately became stocked. Against all evidence, I cannot avoid suspecting that organic particles (my "gemmules" from the separate cells of the lower creatures!) will keep alive and afterwards multiply under proper conditions.

What an interesting problem it is.

237. TO W.B. TEGETMEIER. Down, July 15th [1870]

It is very long since I have heard from you, and I am much obliged for your letter. It is good news that you are going to bring out a new edition of your Poultry book (237/1. "The Poultry Book," 1872.), and you are quite at liberty to use all my materials. Thanks for the curious case of the wild duck variation: I have heard of other instances of a tendency to vary in one out of a large litter or family. I have too many things in hand at present to profit by your offer of the loan of the American Poultry book.

Pray keep firm to your idea of working out the subject of analogous variations (237/2. "By this term I mean that similar characters occasionally make their appearance in the several varieties or races descended from the same species, and more rarely in the offspring of widely distinct species" ("Animals and Plants," II., Edition II., page 340).) with pigeons; I really think you might thus make a novel and valuable contribution to science. I can, however, quite understand how much your time must be occupied with the never-ending, always-beginning editorial cares.

I keep much as usual, and crawl on with my work.

238. TO J.D. HOOKER. Down, September 27th [1870]

Yours was a splendid letter, and I was very curious to hear something about the Liverpool meeting (238/1. Mr. Huxley was President of the British Association at Liverpool in 1870. His Presidential Address on "Biogenesis and Abiogenesis" is reprinted in his collected Essays, VIII., page 229. Some account of the meeting is given in Huxley's "Life and Letters," Volume I., pages 332, 336.), which I much wished to be successful for Huxley's sake. I am surprised that you think his address would not have been clear to the public; it seemed to me as clear as water. The general line of his argument might have been answered by the case of spontaneous combustion: tens of thousands of cases of things having been seen to be set on fire would be no true argument against any one who maintained that flames sometimes spontaneously burst forth. I am delighted at the apotheosis of Sir Roderick; I can fancy what neat and appropriate speeches he would make to each nobleman as he entered the gates of heaven. You ask what I think about Tyndall's lecture (238/2. Tyndall's lecture was "On the Scientific Uses of the Imagination."): it seemed to me grand and very interesting, though I could not from ignorance quite follow some parts, and I longed to tell him how immensely it would have been improved if all the first part had been made very much less egotistical. George independently arrived at the same conclusion, and liked all the latter part extremely. He thought the first part not only egotistical, but rather clap-trap.

How well Tyndall puts the "as if" manner of philosophising, and shows that it is justifiable. Some of those confounded Frenchmen have lately been pitching into me for using this form of proof or argument.

I have just read Rolleston's address in "Nature" (238/3. Presidential Address to the Biological Section, British Association, 1870. "Nature," September 22nd, 1870, page 423. Rolleston referred to the vitality of seeds in soil, a subject on which Darwin made occasional observations. See "Life and Letters," II., page 65.): his style is quite unparalleled! I see he quotes you about seed, so yesterday I went and observed more carefully the case given in the enclosed paper, which perhaps you might like to read and burn.

How true and good what you say about Lyell. He is always the same; Dohrn was here yesterday, and was remarking that no one stood higher in the public estimation of Germany than Lyell.

I am truly and profoundly glad that you are thinking of some general work on Geographical Distribution, or so forth; I hope to God that your incessant occupations may not interrupt this intention. As for my book, I shall not have done the accursed proofs till the end of November (238/4. The proofs of the "Descent of Man" were finished on January 15th, 1871.): good Lord, what a muddled head I have got on my wretched old shoulders.

239. TO H. SETTEGAST. Down, September 29th, 1870

I am very much obliged for your kind letter and present of your beautiful volume. (239/1. "Die Thierzucht," 1868.) Your work is not new to me, for I heard it so highly spoken of that I procured a copy of the first edition. It was a great gratification to me to find a man who had long studied with a philosophical spirit our domesticated animals, and who was highly competent to judge, agreeing to a large extent with my views. I regretted much that I had not known your work when I published my last volumes.

I am surprised and pleased to hear that science is not quite forgotten under the present exciting state of affairs. Every one whom I know in England is an enthusiastic wisher for the full and complete success of Germany.

P.S. I will give one of my two copies of your work to some public scientific library in London.

240. TO THE EDITOR OF THE "PALL MALL GAZETTE." Down, March 24th [1871]

Mr. Darwin presents his compliments to the Editor, and would be greatly obliged if he would address and post the enclosed letter to the author of the two admirable reviews of the "Descent of Man." (240/1. The notices of the "Descent of Man," published in the "Pall Mall Gazette" of March 20th and 21st, 1871, were by Mr. John Morley. We are indebted to the Editor of the "Pall Mall Gazette" for kindly allowing us to consult his file of the journal.)

241. TO JOHN MORLEY. Down, March 24th, 1871

From the spirit of your review in the "Pall Mall Gazette" of my last book, which has given me great pleasure, I have thought that you would perhaps inform me on one point, withholding, if you please, your name.

You say that my phraseology on beauty is "loose scientifically, and philosophically most misleading." (241/1. "Mr. Darwin's work is one of those rare and capital achievements of intellect which effect a grave modification throughout all the highest departments of the realm of opinion...There is throughout the description and examination of Sexual Selection a way of speaking of beauty, which seems to us to be highly unphilosophical, because it assumes a certain theory of beauty, which the most competent modern thinkers are too far from accepting, to allow its assumption to be quite judicious...Why should we only find the aesthetic quality in birds wonderful, when it happens to coincide with our own? In other words, why attribute to them conscious aesthetic qualities at all? There is no more positive reason for attributing aesthetic consciousness to the Argus pheasant than there is for attributing to bees geometric consciousness of the hexagonal prisms and rhombic plates of the hive which they so marvellously construct. Hence the phraseology which Mr. Darwin employs in this part of the subject, though not affecting the degree of probability which may belong to this theory, seems to us to be very loose scientifically, and philosophically most misleading."--"Pall Mall Gazette.") This is not at all improbable, as it is almost a lifetime since I attended to the philosophy of aesthetics, and did not then think that I should ever make use of my conclusions. Can you refer me to any one or two books (for my power of reading is not great) which would illumine me? or can you explain in one or two sentences how I err? Perhaps it would be best for me to explain what I mean by the sense of beauty in its lowest stage of development, and which can only apply to animals. When an intense colour, or two tints in harmony, or a recurrent and symmetrical figure please the eye, or a single sweet note pleases the ear, I call this a sense of beauty; and with this meaning I have spoken (though I now see in not a sufficiently guarded manner) of a taste for the beautiful being the same in mankind (for all savages admire bits of bright cloth, beads, plumes, etc.) and in the lower animals. If the blue and yellow plumage of a macaw (241/2. "What man deems the horrible contrasts of yellow and blue attract the macaw, while ball-and-socket-plumage attracts the Argus pheasant"--"Pall Mall Gazette," March 21st, 1871, page 1075.) pleases the eye of this bird, I should say that it had a sense of beauty, although its taste was bad according to our standard. Now, will you have the kindness to tell me how I can learn to see the error of my ways? Of course I recognise, as indeed I have remarked in my book, that the sense of beauty in the case of scenery, pictures, etc., is something infinitely complex, depending on varied associations and culture of the mind. From a very interesting review in the "Spectator," and from your and Wallace's review, I perceive that I have made a great oversight in not having said what little I could on the acquisition of the sense for the beautiful by man and the lower animals. It would indeed be an immense advantage to an author if he could read such criticisms as yours before publishing. At page 11 of your review you accidentally misquote my words placed by you within inverted commas, from my Volume II., page 354: I say that "man cannot endure any great change," and the omitted words "any great" make all the difference in the discussion. (241/3. "Mr. Darwin tells us, and gives us excellent reasons for thinking, that 'the men of each race prefer what they are accustomed to behold; they cannot endure change.' Yet is there not an inconsistency between this fact and the other that one race differs from another exactly because novelties presented themselves, and were eagerly seized and propagated?")

Permit me to add a few other remarks. I believe your criticism is quite just about my deficient historic spirit, for I am aware of my ignorance in this line. (241/4. "In the historic spirit, however, Mr. Darwin must fairly be pronounced deficient. When, for instance, he speaks of the 'great sin of slavery' having been general among primitive nations, he forgets that, though to hold a slave would be a sinful degradation to a European to-day, the practice of turning prisoners of war into slaves, instead of butchering them, was not a sin at all, but marked a decided improvement in human manners.") On the other hand, if you should ever be led to read again Chapter III., and especially Chapter V., I think you will find that I am not amenable to all your strictures; though I felt that I was walking on a path unknown to me and full of pitfalls; but I had the advantage of previous discussions by able men. I tried to say most emphatically that a great philosopher, law-giver, etc., did far more for the progress of mankind by his writings or his example than by leaving a numerous offspring. I have endeavoured to show how the struggle for existence between tribe and tribe depends on an advance in the moral and intellectual qualities of the members, and not merely on their capacity of obtaining food. When I speak of the necessity of a struggle for existence in order that mankind should advance still higher in the scale, I do not refer to the MOST, but "to the MORE highly gifted men" being successful in the battle for life; I referred to my supposition of the men in any country being divided into two equal bodies--viz., the more and the less highly gifted, and to the former on an average succeeding best.

But I have much cause to apologise for the length of this ill-expressed letter. My sole excuse is the extraordinary interest which I have felt in your review, and the pleasure which I have experienced in observing the points which have attracted your attention. I must say one word more. Having kept the subject of sexual selection in my mind for very many years, and having become more and more satisfied with it, I feel great confidence that as soon as the notion is rendered familiar to others, it will be accepted, at least to a much greater extent than at present. With sincere respect and thanks...

242. TO JOHN MORLEY. Down, April 14th [1871]

As this note requires no answer, I do not scruple to write a few lines to say how faithful and full a resume you have given of my notions on the moral sense in the "Pall Mall," and to make a few extenuating or explanatory remarks. (242/1. "What is called the question of the moral sense is really two: how the moral faculty is acquired, and how it is regulated. Why do we obey conscience or feel pain in disobeying it? And why does conscience prescribe one kind of action and condemn another kind? To put it more technically, there is the question of the subjective existence of conscience, and there is the question of its objective prescriptions. First, why do I think it obligatory to do my duty? Second, why do I think it my duty to do this and not do that? Although, however, the second question ought to be treated independently, for reasons which we shall presently suggest, the historical answer to it, or the various grounds on which men have identified certain sorts of conduct with duty, rather than conduct of the opposite sorts, throws light on the other question of the conditions of growth of the idea of duty as a sovereign and imperial director. Mr. Darwin seems to us not to have perfectly recognised the logical separation between the two sides of the moral sense question. For example, he says (i. 97) that 'philosophers of the derivative school of morals formerly assumed that the foundation of morality lay in a form of Selfishness; but more recently in the Greatest Happiness principle.' But Mr. Mill, to whom Mr. Darwin refers, has expressly shown that the Greatest Happiness principle is a STANDARD, and not a FOUNDATION, and that its validity as a standard of right and wrong action is just as tenable by one who believes the moral sense to be innate, as by one who holds that it is acquired. He says distinctly that the social feelings of mankind form 'the natural basis of sentiment for utilitarian morality.' So far from holding the Greatest Happiness principle to be the foundation of morality, he would describe it as the forming principle of the superstructure of which the social feelings of mankind are the foundation. Between Mr. Darwin and utilitarians, as utilitarians, there is no such quarrel as he would appear to suppose. The narrowest utilitarian could say little more than Mr. Darwin says (ii. 393): 'As all men desire their own happiness, praise or blame is bestowed on actions and motives according as they tend to this end; and, as happiness is an essential part of the general good, the Greatest Happiness principle INDIRECTLY serves as a NEARLY safe standard of right and wrong.' It is perhaps not impertinent to suspect that the faltering adverbs which we have printed in italics indicate no more than the reluctance of a half-conscious convert to pure utilitarianism. In another place (i. 98) he admits that 'as all wish for happiness, the Greatest Happiness principle will have become a most important secondary guide and object, the social instincts, including sympathy, always serving as the primary impulse and guide.' This is just what Mr. Mill says, only instead of calling the principle a secondary guide, he would call it a standard, to distinguish it from the social impulse, in which, as much as Mr. Darwin, he recognises the base and foundation."--"Pall Mall Gazette," April 12th, 1871.) How the mistake which I have made in speaking of greatest happiness as the foundation of morals arose, is utterly unintelligible to me: any time during the last several years I should have laughed such an idea to scorn. Mr. Lecky never made a greater blunder, and your kindness has made you let me off too easily. (242/2. In the first edition of the "Descent of Man," I., page 97, Mr. Lecky is quoted as one of those who assumed that the "foundation of morality lay in a form of selfishness; but more recently in the 'greatest happiness' principle." Mr. Lecky's name is omitted in this connection in the second edition, page 120. In this edition Mr. Darwin makes it clearer that he attaches most importance to the social instinct as the "primary impulse and guide.") With respect to Mr. Mill, nothing would have pleased me more than to have relied on his great authority with respect to the social instincts, but the sentence which I quote at [Volume I.] page 71 ("if, as is my own belief, the moral feelings are not innate, but acquired, they are not for that reason less natural") seems to me somewhat contradictory with the other words which I quote, so that I did not know what to think; more especially as he says so very little about the social instincts. When I speak of intellectual activity as the secondary basis of conscience, I meant in my own mind secondary in period of development; but no one could be expected to understand so great an ellipse. With reference to your last sentence, do you not think that man might have retrograded in his parental, marriage, and other instincts without having retrograded in his social instincts? and I do not think that there is any evidence that man ever existed as a non-social animal. I must add that I have been very glad to read your remarks on the supposed case of the hive-bee: it affords an amusing contrast with what Miss Cobbe has written in the "Theological Review." (242/3. Mr. Darwin says ("Descent of Man" Edition I., Volume I., page 73; Edition II., page 99), "that if men lived like bees our unmarried females would think it a sacred duty to kill their brothers." Miss Cobbe remarks on this "that the principles of social duty would be reversed" ("Theological Review," April 1872). Mr. Morley, on the other hand, says of Darwin's assertion, that it is "as reassuring as the most absolute of moralists could desire. For it is tantamount to saying that the foundations of morality, the distinctions of right and wrong, are deeply laid in the very conditions of social existence; that there is in face of these conditions a positive and definite difference between the moral and the immoral, the virtuous and the vicious, the right and the wrong, in the actions of individuals partaking of that social existence.") Undoubtedly the great principle of acting for the good of all the members of the same community, and therefore the good of the species, would still have held sovereign sway.

243. TO J.D. HOOKER

(243/1. Sir Joseph Hooker wrote (August 5th, 1871) to Darwin about Lord Kelvin's Presidential Address at the Edinburgh meeting of the British Association: "It seems to me to be very able indeed; and what a good notion it gives of the gigantic achievement of mathematicians and physicists!--it really made one giddy to read of them. I do not think Huxley will thank him for his reference to him as a positive unbeliever in spontaneous generation--these mathematicians do not seem to me to distinguish between un-belief and a-belief. I know no other name for the state of mind that is produced under the term scepticism. I had no idea before that pure Mathematics had achieved such wonders in practical science. The total absence of any allusion to Tyndall's labours, even when comets are his theme, seems strange to me.")

Haredene, Albury, Guildford, August 6th [1871].

I have read with greatest interest Thomson's address; but you say so EXACTLY AND FULLY all that I think, that you have taken all the words from my mouth; even about Tyndall. It is a gain that so wonderful a man, though no naturalist, should become a convert to evolution; Huxley, it seems, remarked in his speech to this effect. I should like to know what he means about design,--I cannot in the least understand, for I presume he does not believe in special interpositions. (243/2. See "British Association Report," page cv. Lord Kelvin speaks very doubtfully of evolution. After quoting the concluding passage of the "Origin," he goes on, "I have omitted two sentences...describing briefly the hypothesis of 'the origin of species by Natural Selection,' because I have always felt that this hypothesis does not contain the true theory of evolution, IF EVOLUTION THERE HAS BEEN in biology" (the italics are not in the original). Lord Kelvin then describes as a "most valuable and instructive criticism," Sir John Herschel's remark that the doctrine of Natural Selection is "too like the Laputan method of making books, and that it did not sufficiently take into account a continually guiding and controlling intelligence." But it should be remembered that it was in this address of Lord Kelvin's that he suggested the possibility of "seed-bearing meteoric stones moving about through space" inoculating the earth with living organisms; and if he assumes that the whole population of the globe is to be traced back to these "moss-grown fragments from the ruins of another world," it is obvious that he believes in a form of evolution, and one in which a controlling intelligence is not very obvious, at all events not in the initial and all-important stage.) Herschel's was a good sneer. It made me put in the simile about Raphael's Madonna, when describing in the "Descent of Man" the manner of formation of the wondrous ball-and-socket ornaments, and I will swear to the truth of this case. (243/3. See "Descent of Man," II., page 141. Darwin says that no one will attribute the shading of the "eyes" on the wings of the Argus pheasant to the "fortuitous concourse of atoms of colouring-matter." He goes on to say that the development of the ball-and-socket effect by means of Natural Selection seems at first as incredible as that "one of Raphael's Madonnas should have been formed by the selection of chance daubs of paint." The remark of Herschel's, quoted in "Life and Letters," II., page 241, that the "Origin" illustrates the "law of higgledy-piggledy," is probably a conversational variant of the Laputan comparison which gave rise to the passage in the "Descent of Man" (see Letter 130).)

You know the oak-leaved variety of the common honeysuckle; I could not persuade a lady that this was not the result of the honeysuckle climbing up a young oak tree! Is this not like the Viola case?

244. TO JOHN LUBBOCK (LORD AVEBURY). Haredene, Albury, Guildford, August 12th [1871]

I hope the proof-sheets having been sent here will not inconvenience you. I have read them with infinite satisfaction, and the whole discussion strikes me as admirable. I have no books here, and wish much I could see a plate of Campodea. (244/1. "On the Origin of Insects." By Sir John Lubbock, Bart. "Journ. Linn. Soc. (Zoology)," Volume XI., 1873, pages 422-6. (Read November 2nd, 1871.) In the concluding paragraph the author writes, "If these views are correct the genus Campodea [a beetle] must be regarded as a form of remarkable interest, since it is the living representative of a primaeval type from which not only the Collembola and Thysanura, but the other great orders of insects, have all derived their origin." (See also "Brit. Assoc. Report," 1872, page 125--Address by Sir John Lubbock; and for a figure of Campodea see "Nature," Volume VII., 1873, page 447.) I never reflected much on the difficulty which you indicate, and on which you throw so much light. (244/2. The difficulty alluded to is explained by the first sentence of Lord Avebury's paper. "The Metamorphoses of this group (Insects) have always seemed to me one of the greatest difficulties of the Darwinian theory...I feel great difficulty in conceiving by what natural process an insect with a suctorial mouth, like that of a gnat or butterfly, could be developed from a powerfully mandibulate type like the orthoptera, or even from the neuroptera...A clue to the difficulty may, I think, be found in the distinction between the developmental and adaptive changes to which I called the attention of the Society in a previous memoir."

The distinction between developmental and adaptive changes is mentioned, but not discussed, in the paper "On the Origin of Insects" (loc. cit., page 422); in a former paper, "On the Development of Chloeon (Ephemera) dimidiatum ("Trans. Linn. Soc." XXV. page 477, 1866), this question is dealt with at length.) I have only a few trifling remarks to make. At page 44 I wish you had enlarged a little on what you have said of the distinction between developmental and adaptive changes; for I cannot quite remember the point, and others will perhaps be in the same predicament. I think I always saw that the larva and the adult might be separately modified to any extent. Bearing in mind what strange changes of function parts undergo, with the intermediate state of use (244/3. This slightly obscure phrase may be paraphrased, "the gradational stages being of service to the organism."), it seems to me that you speak rather too boldly on the impossibility of a mandibulate insect being converted into a sucking insect (244/4. "There are, however, peculiar difficulties in those cases in which, as among the lepidoptera, the same species is mandibulate as a larva and suctorial as an embryo" (Lubbock, "Origin of Insects," page 423).); not that I in the least doubt the value of your explanation.

Cirripedes passing through what I have called a pupal state (244/5. "Hence, the larva in this, its last stage, cannot eat; it may be called a "locomotive Pupa;" its whole organisation is apparently adapted for the one great end of finding a proper site for its attachment and final metamorphosis." ("A Monograph on the Sub-Class Cirripedia." By Charles Darwin. London, Ray Soc., 1851.)) so far as their mouths are concerned, rather supports what you say at page 52.

At page 40 your remarks on the Argus pheasant (244/6. There is no mention of the Argus pheasant in the published paper.) (though I have not the least objection to them) do not seem to me very appropriate as being related to the mental faculties. If you can spare me these proof-sheets when done with, I shall be obliged, as I shall be correcting a new edition of the "Origin" when I return home, though this subject is too large for me to enter on. I thank you sincerely for the great interest which your discussion has given me.

245. TO J.D. HOOKER

(245/1. The following letter refers to Mivart's "Genesis of Species.")

Down, September 16th [1871].

I am preparing a new and cheap edition of the "Origin," and shall introduce a new chapter on gradation, and on the uses of initial commencements of useful structures; for this, I observe, has produced the greatest effect on most persons. Every one of his [Mivart's] cases, as it seems to me, can be answered in a fairly satisfactory manner. He is very unfair, and never says what he must have known could be said on my side. He ignores the effect of use, and what I have said in all my later books and editions on the direct effects of the conditions of life and so-called spontaneous variation. I send you by this post a very clever, but ill-written review from N. America by a friend of Asa Gray, which I have republished. (245/2. Chauncey Wright in the "North American Review," Volume CXIII., reprinted by Darwin and published as a pamphlet (see "Life and Letters," III., page 145).)

I am glad to hear about Huxley. You never read such strong letters Mivart wrote to me about respect towards me, begging that I would call on him, etc., etc.; yet in the "Q. Review" (245/3. See "Quarterly Review," July 1871; also "Life and Letters," III., page 147.) he shows the greatest scorn and animosity towards me, and with uncommon cleverness says all that is most disagreeable. He makes me the most arrogant, odious beast that ever lived. I cannot understand him; I suppose that accursed religious bigotry is at the root of it. Of course he is quite at liberty to scorn and hate me, but why take such trouble to express something more than friendship? It has mortified me a good deal.

246. TO J.D. HOOKER. Down, October 4th [1871]

I am quite delighted that you think so highly of Huxley's article. (246/1. A review of Wallace's "Natural Selection," of Mivart's "Genesis of Species," and of the "Quarterly Review" article on the "Descent of Man" (July, 1871), published in the "Contemporary Review" (1871), and in Huxley's "Collected Essays," II., page 120.) I was afraid of saying all I thought about it, as nothing is so likely as to make anything appear flat. I thought of, and quite agreed with, your former saying that Huxley makes one feel quite infantile in intellect. He always thus acts on me. I exactly agree with what you say on the several points in the article, and I piled climax on climax of admiration in my letter to him. I am not so good a Christian as you think me, for I did enjoy my revenge on Mivart. He (i.e. Mivart) has just written to me as cool as a cucumber, hoping my health is better, etc. My head, by the way, plagues me terribly, and I have it light and rocking half the day. Farewell, dear old friend--my best of friends.

247. TO JOHN FISKE

(247/1. Mr. Fiske, who is perhaps best known in England as the author of "Outlines of Cosmic Philosophy," had sent to Mr. Darwin some reports of the lectures given at Harvard University. The point referred to in the postscript in Mr. Darwin's letter is explained by the following extract from Mr. Fiske's work: "I have endeavoured to show that the transition from animality (or bestiality, stripping the word of its bad connotations) to humanity must have been mainly determined by the prolongation of infancy or immaturity which is consequent upon a high development of intelligence, and which must have necessitated the gradual grouping together of pithecoid men into more or less definite families." (See "Descent," I., page 13, on the prolonged infancy of the anthropoid apes.))

Down, November 9th, 1871.

I am greatly obliged to you for having sent me, through my son, your lectures, and for the very honourable manner in which you allude to my works. The lectures seem to me to be written with much force, clearness, and originality. You show also a truly extraordinary amount of knowledge of all that has been published on the subject. The type in many parts is so small that, except to young eyes, it is very difficult to read. Therefore I wish that you would reflect on their separate publication, though so much has been published on the subject that the public may possibly have had enough. I hope that this may be your intention, for I do not think I have ever seen the general argument more forcibly put so as to convert unbelievers.

It has surprised and pleased me to see that you and others have detected the falseness of much of Mr. Mivart's reasoning. I wish I had read your lectures a month or two ago, as I have been preparing a new edition of the "Origin," in which I answer some special points, and I believe I should have found your lectures useful; but my MS. is now in the printer's hands, and I have not strength or time to make any more additions.

P.S.--By an odd coincidence, since the above was written I have received your very obliging letter of October 23rd. I did notice the point to which you refer, and will hereafter reflect more over it. I was indeed on the point of putting in a sentence to somewhat of the same effect in the new edition of the "Origin," in relation to the query--Why have not apes advanced in intellect as much as man? but I omitted it on account of the asserted prolonged infancy of the orang. I am also a little doubtful about the distinction between gregariousness and sociability.

...When you come to England I shall have much pleasure in making your acquaintance; but my health is habitually so weak that I have very small power of conversing with my friends as much as I wish. Let me again thank you for your letter. To believe that I have at all influenced the minds of able men is the greatest satisfaction I am capable of receiving.

248. TO E. HACKEL. Down, December 27th, 1871

I thank you for your very interesting letter, which it has given me much pleasure to receive. I never heard of anything so odd as the Prior in the Holy Catholic Church believing in our ape-like progenitors. I much hope that the Jesuits will not dislodge him.

What a wonderfully active man you are! and I rejoice that you have been so successful in your work on sponges. (248/1. "Die Kalkschwamme: eine Monographie; 3 volumes: Berlin, 1872. H.J. Clark published a paper "On the Spongiae Ciliatae as Infusoria flagellata" in the "Mem. Boston Nat. Hist. Soc." Volume I., Part iii., 1866. See Hackel, op. cit., Volume I., page 24.) Your book with sixty plates will be magnificent. I shall be glad to learn what you think of Clark's view of sponges being flagellate infusorians; some observers in this country believe in him. I am glad you are going fully to consider inheritance, which is an all-important subject for us. I do not know whether you have ever read my chapter on pangenesis. My ideas have been almost universally despised, and I suppose that I was foolish to publish them; yet I must still think that there is some truth in them. Anyhow, they have aided me much in making me clearly understand the facts of inheritance.

I have had bad health this last summer, and during two months was able to do nothing; but I have now almost finished a next edition of the "Origin," which Victor Carus is translating. (248/2. See "Life and Letters," III., page 49.) There is not much new in it, except one chapter in which I have answered, I hope satisfactorily, Mr. Mivart's supposed difficulty on the incipient development of useful structures. I have also given my reasons for quite disbelieving in great and sudden modifications. I am preparing an essay on expression in man and the lower animals. It has little importance, but has interested me. I doubt whether my strength will last for much more serious work. I hope, however, to publish next summer the results of my long-continued experiments on the wonderful advantages derived from crossing. I shall continue to work as long as I can, but it does not much signify when I stop, as there are so many good men fully as capable, perhaps more capable, than myself of carrying on our work; and of these you rank as the first.

With cordial good wishes for your success in all your work and for your happiness.

249. TO E. RAY LANKESTER. Down, April 15th [1872]

Very many thanks for your kind consideration. The correspondence was in the "Athenaeum." I got some mathematician to make the calculation, and he blundered and caused me much shame. I send scrap of proofs from last edition of the "Origin," with the calculation corrected. What grand work you did at Naples! I can clearly see that you will some day become our first star in Natural History.

(249/1. Here follows the extract from the "Origin," sixth edition, page 51: "The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase. It will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old; if this be so, after a period of from 740 to 750 years, there would be nearly nineteen million elephants alive, descended from the first pair." In the fifth edition, page 75, the passage runs: "If this be so, at the end of the fifth century, there would be alive fifteen million elephants, descended from the first pair" (see "Athenaeum," June 5, July 3, 17, 24, 1869).)

250. TO C. LYELL. Down, May 10th [1872]

I received yesterday morning your present of that work to which I, for one, as well as so many others, owe a debt of gratitude never to be forgotten. I have read with the greatest interest all the special additions; and I wish with all my heart that I had the strength and time to read again every word of the whole book. (250/1. "Principles of Geology," Edition XII., 1875.) I do not agree with all your criticisms on Natural Selection, nor do I suppose that you would expect me to do so. We must be content to differ on several points. I differ must about your difficulty (page 496) (250/2. In Chapter XLIII. Lyell treats of "Man considered with reference to his Origin and Geographical Distribution." He criticizes the view that Natural Selection is capable of bringing about any amount of change provided a series of minute transitional steps can be pointed out. "But in reality," he writes, "it cannot be said that we obtain any insight into the nature of the forces by which a higher grade of organisation or instinct is evolved out of a lower one by becoming acquainted with a series of gradational forms or states, each having a very close affinity with the other."..."It is when there is a change from an inferior being to one of superior grade, from a humbler organism to one endowed with new and more exalted attributes, that we are made to feel that, to explain the difficulty, we must obtain some knowledge of those laws of variation of which Mr. Darwin grants that we are at present profoundly ignorant" (op. cit., pages 496-97).) on a higher grade of organisation being evolved out of lower ones. Is not a very clever man a grade above a very dull one? and would not the accumulation of a large number of slight differences of this kind lead to a great difference in the grade of organisation? And I suppose that you will admit that the difference in the brain of a clever and dull man is not much more wonderful than the difference in the length of the nose of any two men. Of course, there remains the impossibility of explaining at present why one man has a longer nose than another. But it is foolish of me to trouble you with these remarks, which have probably often passed through your mind. The end of this chapter (XLIII.) strikes me as admirably and grandly written. I wish you joy at having completed your gigantic undertaking, and remain, my dear Lyell,

Your ever faithful and now very old pupil, CHARLES DARWIN.

251. TO J. TRAHERNE MOGGRIDGE. Sevenoaks, October 9th [1872]

I have just received your note, forwarded to me from my home. I thank you very truly for your intended present, and I am sure that your book will interest me greatly. I am delighted that you have taken up the very difficult and most interesting subject of the habits of insects, on which Englishmen have done so little. How incomparably more valuable are such researches than the mere description of a thousand species! I daresay you have thought of experimenting on the mental powers of the spiders by fixing their trap-doors open in different ways and at different angles, and observing what they will do.

We have been here some days, and intend staying some weeks; for I was quite worn out with work, and cannot be idle at home.

I sincerely hope that your health is not worse.

252. TO A. HYATT

(252/1. The correspondence with Professor Hyatt, of Boston, U.S., originated in the reference to his and Professor Cope's theories of acceleration and retardation, inserted in the sixth edition of the "Origin," page 149.

Mr. Darwin, on receiving from Mr. Hyatt a copy of his "Fossil Cephalopods of the Museum of Comparative Zoology. Embryology," from the "Bull. Mus. Comp. Zool." Harvard, Volume III., 1872, wrote as follows (252/2. Part of this letter was published in "Life and Letters," III., page 154.):--)

October 10th, 1872.

I am very much obliged to you for your kindness in having sent me your valuable memoir on the embryology of the extinct cephalopods. The work must have been one of immense labour, and the results are extremely interesting. Permit me to take this opportunity to express my sincere regret at having committed two grave errors in the last edition of my "Origin of Species," in my allusion to yours and Professor Cope's views on acceleration and retardation of development. I had thought that Professor Cope had preceded you; but I now well remember having formerly read with lively interest, and marked, a paper by you somewhere in my library, on fossil cephalopods, with remarks on the subject. (252/3. The paper seems to be "On the Parallelism between the Different Stages of Life in the Individual and those in the Entire Group of the Molluscous Order Tetrabranchiata," from the "Boston. Soc. Nat. Hist. Mem." I., 1866-69, page 193. On the back of the paper is written, "I cannot avoid thinking this paper fanciful.") It seems also that I have quite misrepresented your joint view; this has vexed me much. I confess that I have never been able to grasp fully what you wish to show, and I presume that this must be owing to some dulness on my part...As the case stands, the law of acceleration and retardation seems to me to be a simple [?] statement of facts; but the statement, if fully established, would no doubt be an important step in our knowledge. But I had better say nothing more on the subject, otherwise I shall perhaps blunder again. I assure you that I regret much that I have fallen into two such grave errors.

253. A. HYATT TO CHARLES DARWIN

(253/1. Mr. Hyatt replied in a long letter, of which only a small part is here given.

Cannstadt bei Stuttgart, November 1872.

The letter with which you have honoured me, bearing the date of October 10th, has just reached here after a voyage to America and back.

I have long had it in mind to write you upon the subject of which you speak, but have been prevented by a very natural feeling of distrust in the worthiness and truth of the views which I had to present.

There is certainly no occasion to apologise for not having quoted my paper. The law of acceleration and retardation of development was therein used to explain the appearance of other phenomena, and might, as it did in nearly all cases, easily escape notice.

My relations with Prof. Cope are of the most friendly character; and although fortunate in publishing a few months ahead, I consider that this gives me no right to claim anything beyond such an amount of participation in the discovery, if it may be so called, as the thoroughness and worth of my work entitles me to...

The collections which I have studied, it will be remembered, are fossils collected without special reference to the very minute subdivisions, such as the subdivisions of the Lower or Middle Lias as made by the German authors, especially Quenstedt and Oppel, but pretty well defined for the larger divisions in which the species are also well defined. The condition of the collections as regards names, etc., was chaotic, localities alone, with some few exceptions, accurate. To put this in order they were first arranged according to their adult characteristics. This proving unsatisfactory, I determined to test thoroughly the theory of evolution by following out the developmental history of each species and placing them within their formations, Middle or Upper Lias, Oolite or so, according to the extent to which they represented each other's characteristics. Thus an adult of simple structure being taken as the starting-point which we will call a, another species which was a in its young stage and became b in the adult was placed above it in the zoological series. By this process I presently found that a, then a b and a b c, c representing the adult stage, were very often found; but that practically after passing these two or three stages it did not often happen that a species was found which was a b c in the young and then became d in the adult. But on the other hand I very frequently found one which, while it was a in the young, skipped the stages b and c and became d while still quite young. Then sometimes, though more rarely, a species would be found belonging to the same series, which would be a in the young and with a very faint and fleeting resemblance to d at a later stage, pass immediately while still quite young to the more advanced characteristics represented by e, and hold these as its specific characteristics until old age destroyed them. This skipping is the highest exemplification, or rather manifestation, of acceleration in development. In alluding to the history of diseases and inheritance of characteristics, you in your "Origin of Species" allude to the ordinary manifestation of acceleration, when you speak of the tendency of diseases or characteristics to appear at younger periods in the life of the child than of its parents. This, according to my observations, is a law, or rather mode, of development, which is applicable to all characteristics, and in this way it is possible to explain why the young of later-occurring animals are like the adult stages of those which preceded them in time. If I am not mistaken you have intimated something of this sort also in your first edition, but I have not been able to find it lately. Of course this is a very normal condition of affairs when a series can be followed in this way, beginning with species a, then going through species a b to a b c, then a b d or a c d, and then a d e or simply a e, as it sometimes comes. Very often the acceleration takes place in two closely connected series, thus:

a--ab--abd--ae---ad

in which one series goes on very regularly, while another lateral offshoot of a becomes d in the adult. This is an actual case which can be plainly shown with the specimens in hand, and has been verified in the collections here. Retardation is entirely Prof. Cope's idea, but I think also easily traceable. It is the opponent of acceleration, so to speak, or the opposite or negative of that mode of development. Thus series may occur in which, either in size or characteristics, they return to former characteristics; but a better discussion of this point you will find in the little treatise which I send by the same mail as this letter, "On Reversions among the Ammonites."

254. TO A. HYATT. Down, December 4th, 1872

I thank you sincerely for your most interesting letter. You refer much too modestly to your own knowledge and judgment, as you are much better fitted to throw light on your own difficult problems than I am.

It has quite annoyed me that I do not clearly understand yours and Prof. Cope's views (254/1. Prof. Cope's views may be gathered from his "Origin of the Fittest" 1887; in this book (page 41) is reprinted his "Origin of Genera" from the "Proc. Philadelph. Acad. Nat. Soc." 1868, which was published separately by the author in 1869, and which we believe to be his first publication on the subject. In the preface to the "Origin of the Fittest," page vi, he sums up the chief points in the "Origin of Genera" under seven heads, of which the following are the most important:--"First, that development of new characters has been accomplished by an ACCELERATION or RETARDATION in the growth of the parts changed...Second, that of EXACT PARALLELISM between the adult of one individual or set of individuals, and a transitional stage of one or more other individuals. This doctrine is distinct from that of an exact parallelism, which had already been stated by von Baer." The last point is less definitely stated by Hyatt in his letter of December 4th, 1872. "I am thus perpetually led to look upon a series very much as upon an individual, and think that I have found that in many instances these afford parallel changes." See also "Lamarck the Founder of Evolution, by A.S. Packard: New York, 1901.) and the fault lies in some slight degree, I think, with Prof. Cope, who does not write very clearly. I think I now understand the terms "acceleration" and "retardation"; but will you grudge the trouble of telling me, by the aid of the following illustration, whether I do understand rightly? When a fresh-water decapod crustacean is born with an almost mature structure, and therefore does not pass, like other decapods, through the Zoea stage, is this not a case of acceleration? Again, if an imaginary decapod retained, when adult, many Zoea characters, would this not be a case of retardation? If these illustrations are correct, I can perceive why I have been so dull in understanding your views. I looked for something else, being familiar with such cases, and classing them in my own mind as simply due to the obliteration of certain larval or embryonic stages. This obliteration I imagined resulted sometimes entirely from that law of inheritance to which you allude; but that it in many cases was aided by Natural Selection, as I inferred from such cases occurring so frequently in terrestrial and fresh-water members of groups, which retain their several embryonic stages in the sea, as long as fitting conditions are present.

Another cause of my misunderstanding was the assumption that in your series

a--ab--abd--ae,--------ad

the differences between the successive species, expressed by the terminal letter, was due to acceleration: now, if I understand rightly, this is not the case; and such characters must have been independently acquired by some means.

The two newest and most interesting points in your letter (and in, as far as I think, your former paper) seem to me to be about senile characteristics in one species appearing in succeeding species during maturity; and secondly about certain degraded characters appearing in the last species of a series. You ask for my opinion: I can only send the conjectured impressions which have occurred to me and which are not worth writing. (It ought to be known whether the senile character appears before or after the period of active reproduction.) I should be inclined to attribute the character in both your cases to the laws of growth and descent, secondarily to Natural Selection. It has been an error on my part, and a misfortune to me, that I did not largely discuss what I mean by laws of growth at an early period in some of my books. I have said something on this head in two new chapters in the last edition of the "Origin." I should be happy to send you a copy of this edition, if you do not possess it and care to have it. A man in extreme old age differs much from a young man, and I presume every one would account for this by failing powers of growth. On the other hand the skulls of some mammals go on altering during maturity into advancing years; as do the horns of the stag, the tail-feathers of some birds, the size of fishes etc.; and all such differences I should attribute simply to the laws of growth, as long as full vigour was retained. Endless other changes of structure in successive species may, I believe, be accounted for by various complex laws of growth. Now, any change of character thus induced with advancing years in the individual might easily be inherited at an earlier age than that at which it first supervened, and thus become characteristic of the mature species; or again, such changes would be apt to follow from variation, independently of inheritance, under proper conditions. Therefore I should expect that characters of this kind would often appear in later-formed species without the aid of Natural Selection, or with its aid if the characters were of any advantage. The longer I live, the more I become convinced how ignorant we are of the extent to which all sorts of structures are serviceable to each species. But that characters supervening during maturity in one species should appear so regularly, as you state to be the case, in succeeding species, seems to me very surprising and inexplicable.

With respect to degradation in species towards the close of a series, I have nothing to say, except that before I arrived at the end of your letter, it occurred to me that the earlier and simpler ammonites must have been well adapted to their conditions, and that when the species were verging towards extinction (owing probably to the presence of some more successful competitors) they would naturally become re-adapted to simpler conditions. Before I had read your final remarks I thought also that unfavourable conditions might cause, through the law of growth, aided perhaps by reversion, degradation of character. No doubt many new laws remain to be discovered. Permit me to add that I have never been so foolish as to imagine that I have succeeded in doing more than to lay down some of the broad outlines of the origin of species.

After long reflection I cannot avoid the conviction that no innate tendency to progressive development exists, as is now held by so many able naturalists, and perhaps by yourself. It is curious how seldom writers define what they mean by progressive development; but this is a point which I have briefly discussed in the "Origin." I earnestly hope that you may visit Hilgendorf's famous deposit. Have you seen Weismann's pamphlet "Einfluss der Isolirung," Leipzig, 1872? He makes splendid use of Hilgendorf's admirable observations. (254/2. Hilgendorf, "Monatsb. K. Akad." Berlin, 1866. For a semi-popular account of Hilgendorf's and Hyatt's work on this subject, see Romanes' "Darwin and after Darwin," I., page 201.) I have no strength to spare, being much out of health; otherwise I would have endeavoured to have made this letter better worth sending. I most sincerely wish you success in your valuable and difficult researches.

I have received, and thank you, for your three pamphlets. As far as I can judge, your views seem very probable; but what a fearfully intricate subject is this of the succession of ammonites. (254/3. See various papers in the publications of the "Boston Soc. Nat. Hist." and in the "Bulletin of the Harvard Museum of Comp. Zoology.")

255. A. HYATT TO CHARLES DARWIN. Cannstadt bei Stuttgart, December 8th, 1872

The quickness and earnestness of your reply to my letter gives me the greatest encouragement, and I am much delighted at the unexpected interest which your questions and comments display. What you say about Prof. Cope's style has been often before said to me, and I have remarked in his writings an unsatisfactory treatment of our common theory. This, I think, perhaps is largely due to the complete absorption of his mind in the contemplation of his subject: this seems to lead him to be careless about the methods in which it may be best explained. He has, however, a more extended knowledge than I have, and has in many ways a more powerful grasp of the subject, and for that very reason, perhaps, is liable to run into extremes. You ask about the skipping of the Zoea stage in fresh-water decapods: is this an illustration of acceleration? It most assuredly is, if acceleration means anything at all. Again, another and more general illustration would be, if, among the marine decapods, a series could be formed in which the Zoea stage became less and less important in the development, and was relegated to younger and younger stages of the development, and finally disappeared in those to which you refer. This is the usual way in which the accelerated mode of development manifests itself; though near the lowest or earliest occurring species it is also to be looked for. Perhaps this to which you allude is an illustration somewhat similar to the one which I have spoken of in my series,

a--ab--abc--ae--------ad,

which like "a d" comes from the earliest of a series, though I should think from the entire skipping of the Zoea stage that it must be, like "a e," the result of a long line of ancestors. In fact, the essential point of our theory is, that characteristics are ever inherited by the young at earlier periods than they are assumed in due course of growth by the parents, and that this must eventually lead to the extinction or skipping of these characteristics altogether...

Such considerations as these and the fact that near the heads of series or near the latest members of series, and not at the beginning, were usually found the accelerated types, which skipped lower characteristics and developed very suddenly to a higher and more complex standpoint in structure, led both Cope and [myself] into what may be a great error. I see that it has led you at least into the difficulty of which you very rightly complain, and which, I am sorry to see, has cost you some of your valuable time. We presumed that because characteristics were perpetually inherited at earlier stages, that this very concentration of the developed characteristics made room for the production of differences in the adult descendants of any given pair. Further, that in the room thus made other different characteristics must be produced, and that these would necessarily appear earlier in proportion as the species was more or less accelerated, and be greater or less in the same proportion. Finally, that in the most accelerated, such as "a c" or "a d," the difference would be so great as to constitute distinct genera. Cope and I have differed very much, while he acknowledged the action of the accumulated mode of development only when generic characteristics or greater differences were produced, I saw the same mode of development to be applicable in all cases and to all characteristics, even to diseases. So far the facts bore us out, but when we assumed that the adult differences were the result of the accelerated mode of development, we were perhaps upon rather insecure ground. It is evidently this assumption which has led you to misunderstand the theory. Cope founded his belief, that the adult characteristics were also the result of acceleration, if I rightly remember it, mainly upon the class of facts spoken of above in man where a sudden change into two organs may produce entirely new and unexpected differences in the whole organisation, and upon the changes which acceleration appeared to produce in the development of each succeeding species. Your difficulty in understanding the theory and the observations you have made show me at once what my own difficulties have been, but of these I will not speak at present, as my letter is spinning itself out to a fearful length.

(255/1. After speaking of Cope's comparison of acceleration and retardation in evolution to the force of gravity in physical matters Mr. Hyatt goes on:--)

Now it [acceleration] seems to me to explain less and less the origin of adult progressive characteristics or simply differences, and perhaps now I shall get on faster with my work.

256. TO A. HYATT. Down, December 14th [1872]

(256/1. In reply to the above letter (255) from Mr. Hyatt.)

Notwithstanding the kind consideration shown in your last sentence, I must thank you for your interesting and clearly expressed letter. I have directed my publisher to send you a copy of the last edition of the "Origin," and you can, if you like, paste in the "From the Author" on next page. In relation to yours and Professor Cope's view on "acceleration" causing a development of new characters, it would, I think, be well if you were to compare the decapods which pass and do not pass through the Zoea stage, and the one group which does (according to Fritz Muller) pass through to the still earlier Nauplius stages, and see if they present any marked differences. You will, I believe, find that this is not the case. I wish it were, for I have often been perplexed at the omission of embryonic stages as well as the acquirement of peculiar stages appearing to produce no special result in the mature form.

(256/2. The remainder of this letter is missing, and the whole of the last sentence is somewhat uncertainly deciphered. (Note by Mr. Hyatt.))

257. TO A. HYATT. Down, February 13th, 1877

I thank you for your very kind, long, and interesting letter. The case is so wonderful and difficult that I dare not express any opinion on it. Of course, I regret that Hilgendorf has been proved to be so greatly in error (257/1. This refers to a controversy with Sandberger, who had attacked Hilgendorf in the "Verh. der phys.-med. Ges. zu Wurzburg," Bd. V., and in the "Jahrb. der Malakol. Ges." Bd. I., to which Hilgendorf replied in the "Zeitschr. d. Deutschen geolog. Ges." Jahrb. 1877. Hyatt's name occurs in Hilgendorf's pages, but we find no reference to any paper of this date; his well-known paper is in the "Boston. Soc. Nat. Hist." 1880. In a letter to Darwin (May 23rd, 1881) Hyatt regrets that he had no opportunity of a third visit to Steinheim, and goes on: "I should then have done greater justice to Hilgendorf, for whom I have such a high respect."), but it is some selfish comfort to me that I always felt so much misgiving that I never quoted his paper. (257/2. In the fifth edition of the "Origin" (page 362), however, Darwin speaks of the graduated forms of Planorbis multiformis, described by Hilgendorf from certain beds in Switzerland, by which we presume he meant the Steinheim beds in Wurtemberg.) The variability of these shells is quite astonishing, and seems to exceed that of Rubus or Hieracium amongst plants. The result which surprises me most is that the same form should be developed from various and different progenitors. This seems to show how potent are the conditions of life, irrespectively of the variations being in any way beneficial.

The production of a species out of a chaos of varying forms reminds me of Nageli's conclusion, as deduced from the study of Hieracium, that this is the common mode in which species arise. But I still continue to doubt much on this head, and cling to the belief expressed in the first edition of the "Origin," that protean or polymorphic species are those which are now varying in such a manner that the variations are neither advantageous nor disadvantageous. I am glad to hear of the Brunswick deposit, as I feel sure that the careful study of such cases is highly important. I hope that the Smithsonian Institution will publish your memoir.

258. TO A. DE CANDOLLE. Down, January 18th [1873]

It was very good of you to give up so much of your time to write to me your last interesting letter. The evidence seems good about the tameness of the alpine butterflies, and the fact seems to me very surprising, for each butterfly can hardly have acquired its experience during its own short life. Will you be so good as to thank M. Humbert for his note, which I have been glad to read. I formerly received from a man, not a naturalist, staying at Cannes a similar account, but doubted about believing it. The case, however, does not answer my query--viz., whether butterflies are attracted by bright colours, independently of the supposed presence of nectar?

I must own that I have great difficulty in believing that any temporary condition of the parents can affect the offspring. If it last long enough to affect the health or structure of the parents, I can quite believe the offspring would be modified. But how mysterious a subject is that of generation! Although my hypothesis of pangenesis has been reviled on all sides, yet I must still look at generation under this point of view; and it makes me very averse to believe in an emotion having any effect on the offspring. Allow me to add one word about blushing and shyness: I intended only to say the habit was primordially acquired by attention to the face, and not that each shy man now attended to his personal appearance.

259. TO J.D. HOOKER. Down, June 28th, 1873

I write a line to wish you good-bye, as I hear you are off on Wednesday, and to thank you for the Dionoea, but I cannot make the little creature grow well. I have this day read Bentham's last address, and must express my admiration of it. (259/1. Presidential address to the Linnean Society, read May 24th, 1873.) Perhaps I ought not to do so, as he fairly crushes me with honour.

I am delighted to see how exactly I agree with him on affinities, and especially on extinct forms as illustrated by his flat-topped tree. (259/2. See page 15 of separate copy: "We should then have the present races represented by the countless branchlets forming the flat-topped summit" of a genealogical tree, in which "all we can do is to map out the summit as it were from a bird's-eye view, and under each cluster, or cluster of clusters, to place as the common trunk an imaginary type of a genus, order, or class according to the depth to which we would go.") My recent work leads me to differ from him on one point--viz., on the separation of the sexes. (259/3. On the question of sexuality, see page 10 of Bentham's address. On the back of Mr. Darwin's copy he has written: "As long as lowest organisms free--sexes separated: as soon as they become attached, to prevent sterility sexes united--reseparated as means of fertilisation, adapted [?] for distant [?] organisms,--in the case of animals by their senses and voluntary movements,--with plants the aid of insects and wind, the latter always existed, and long retained." The two words marked [?] are doubtful. The introduction of freedom or attachedness, as a factor in the problem also occurs in "Cross and Self-fertilisation," page 462. I strongly suspect that sexes were primordially in distinct individuals; then became commonly united in the same individual, and then in a host of animals and some few plants became again separated. Do ask Bentham to send a copy of his address to "Dr. H. Muller, Lippstadt, Prussia," as I am sure it will please him GREATLY.

...When in France write me a line and tell me how you get on, and how Huxley is; but do not do so if you feel idle, and writing bothers you.

260. TO R. MELDOLA

(260/1. This letter, with others from Darwin to Meldola, is published in "Charles Darwin and the Theory of Natural Selection," by E.B. Poulton, pages 199 et seq., London, 1896.)

Southampton, August 13th, 1873.

I am much obliged for your present, which no doubt I shall find at Down on my return home. I am sorry to say that I cannot answer your question; nor do I believe that you could find it anywhere even approximately answered. It is very difficult or impossible to define what is meant by a large variation. Such graduate into monstrosities or generally injurious variations. I do not myself believe that these are often or ever taken advantage of under nature. It is a common occurrence that abrupt and considerable variations are transmitted in an unaltered state, or not at all transmitted, to the offspring, or to some of them. So it is with tailless or hornless animals, and with sudden and great changes of colour in flowers. I wish I could have given you any answer.

261. TO E.S. MORSE. [Undated.]

I must have the pleasure of thanking you for your kindness in sending me your essay on the Brachiopoda. (261/1. "The Brachiopoda, a Division of Annelida," "Amer. Assoc. Proc." Volume XIX., page 272, 1870, and "Annals and Mag. Nat. Hist." Volume VI., page 267, 1870.) I have just read it with the greatest interest, and you seem to me (though I am not a competent judge) to make out with remarkable clearness an extremely strong case. What a wonderful change it is to an old naturalist to have to look at these "shells" as "worms"; but, as you truly say, as far as external appearance is concerned, the case is not more wonderful than that of cirripedes. I have also been particularly interested by your remarks on the Geological Record, and on the lower and older forms in each great class not having been probably protected by calcareous valves or a shell.

P.S.--Your woodcut of Lingula is most skilfully introduced to compel one to see its likeness to an annelid.

262. TO H. SPENCER

(262/1. Mr. Spencer's book "The Study of Sociology," 1873, was published in the "Contemporary Review" in instalments between May 1872 and October 1873.)

October 31st [1873].

I am glad to receive to-day an advertisement of your book. I have been wonderfully interested by the articles in the "Contemporary." Those were splendid hits about the Prince of Wales and Gladstone. (262/2. See "The Study of Sociology," page 392. Mr. Gladstone, in protest against some words of Mr. Spencer, had said that the appearance of great men "in great crises of human history" were events so striking "that men would be liable to term them providential in a pre-scientific age." On this Mr. Spencer remarks that "in common with the ancient Greek Mr. Gladstone regards as irreligious any explanation of Nature which dispenses with immediate Divine superintendence." And as an instance of the partnership "between the ideas of natural causation and of providential interference," he instances a case where a prince "gained popularity by outliving certain abnormal changes in his blood," and where "on the occasion of his recovery providential aid and natural causation were unitedly recognised by a thanksgiving to God and a baronetcy to the doctor." The passage on Toryism is on page 395, where Mr. Spencer, with his accustomed tolerance, writes: "The desirable thing is that a growth of ideas and feelings tending to produce modification shall be joined with a continuance of ideas and feelings tending to preserve stability." And from this point of view he concludes it to be very desirable that "one in Mr. Gladstone's position should think as he does." The matter is further discussed in the notes to Chapter XVI., page 423.) I never before read a good defence of Toryism. In one place (but I cannot for the life of me recollect where or what it exactly was) I thought that you would have profited by my principle (i.e. if you do not reject it) given in my "Descent of Man," that new characters which appear late in life are those which are transmitted to the same sex alone. I have advanced some pretty strong evidence, and the principle is of great importance in relation to secondary sexual likenesses. (262/3. This refers to Mr. Spencer's discussion of the evolution of the mental traits characteristic of women. At page 377 he points out the importance of the limitation of heredity by sex in this relation. A striking generalisation on this question is given in the "Descent of Man," Edition I., Volume II., page 285: that when the adult male differs from the adult female, he differs in the same way from the young of both sexes. Can this law be applied in the case in which the adult female possesses characters not possessed by the male: for instance, the high degree of intuitive power of reading the mental states of others and of concealing her own--characters which Mr. Spencer shows to be accounted for by the relations between the husband and wife in a state of savagery. If so, the man should resemble "the young of both sexes" in the absence of these special qualities. This seems to be the case with some masculine characteristics, and childishness of man is not without recognition among women: for instance, by Dolly Winthrop in "Silas Marner," who is content with bread for herself, but bakes cake for children and men, whose "stomichs are made so comical, they want a change--they do, I know, God help 'em.") I have applied it to man and woman, and possibly it was here that I thought that you would have profited by the doctrine. I fear that this note will be almost illegible, but I am very tired.

263. G.J. ROMANES TO CHARLES DARWIN

(263/1. This is, we believe, the first letter addressed by the late Mr. Romanes to Mr. Darwin. It was put away with another on the same subject, and inscribed "Romanes on Abortion, with my answer (very important)." Mr. Darwin's answer given below is printed from his rough draft, which is in places barely decipherable. On the subject of these letters consult Romanes, "Darwin and after Darwin," Volume II., page 99, 1895.)

Dunskaith, Parkhill, Ross-shire, July 10th, 1874.

Knowing that you do not dissuade the more attentive of your readers from communicating directly to yourself any ideas they may have upon subjects connected with your writings, I take the liberty of sending the enclosed copy of a letter, which I have recently addressed to Mr. Herbert Spencer. You will perceive that the subject dealt with is the same as that to which a letter of mine in last week's "Nature" [July 2nd, page 164] refers--viz., "Disuse as a Reducing Cause in Species." In submitting this more detailed exposition of my views to your consideration, I should like to state again what I stated in "Nature" some weeks ago, viz., that in propounding the cessation of selection as a reducing cause, I do not suppose that I am suggesting anything which has not occurred to you already. Not only is this principle embodied in the theory set forth in the article on Rudimentary Organs ("Nature," Volume IX.); but it is more than once hinted at in the "Origin," in the passages where rudimentary organs are said to be more variable than others, because no longer under the restraining influence of Natural Selection. And still more distinctly is this principle recognised in page 120.

Thus, in sending you the enclosed letter, I do not imagine that I am bringing any novel suggestions under your notice. As I see that you have already applied the principle in question to the case of artificially-bred structures, I cannot but infer that you have pondered it in connection with naturally-bred structures. What objection, however, you can have seen to this principle in this latter connection, I am unable to divine; and so I think the best course for me to pursue is the one I adopt--viz., to send you my considerations in full.

In the absence of express information, the most natural inference is that the reason you refuse to entertain the principle in question, is because you show the backward tendency of indiscriminate variability [to be] inadequate to contend with the conservative tendency of long inheritance. The converse of this is expressed in the words "That the struggle between Natural Selection on the one hand, and the tendency to reversion and variability on the other hand, will in the course of time cease; and that the most abnormally developed organs may be made constant, I see no reason to doubt" ("Origin," page 121). Certainly not, if, as I doubt not, the word "constant" is intended to bear a relative signification; but to say that constancy can ever become absolute--i.e., that any term of inheritance could secure to an organ a total immunity from the smallest amount of spontaneous variability--to say this would be unwarrantable. Suppose, for instance, that for some reason or other a further increase in the size of a bat's wing should now suddenly become highly beneficial to that animal: we can scarcely suppose that variations would not be forthcoming for Natural Selection to seize upon (unless the limit of possible size has now been reached, which is an altogether distinct matter). And if we suppose that minute variations on the side of increase are thus even now occasionally taking place, much more is it probable that similar variations on the side of decrease are now taking place--i.e., that if the conservative influence of Natural Selection were removed for a long period of time, more variations would ensue below the present size of bat's wings, than above it. To this it may be added, that when the influence of "speedy selection" is removed, it seems in itself highly probable that the structure would, for this reason, become more variable, for the only reason why it ever ceased to be variable (i.e., after attaining its maximum size), was because of the influence of selection constantly destroying those individuals in which a tendency to vary occurred. When, therefore, this force antagonistic to variability was removed, it seems highly probable that the latter principle would again begin to assert itself, and this in a cumulative manner. Those individuals in which a tendency to vary occurred being no longer cut off, they would have as good a chance of leaving progeny to inherit their fluctuating disposition as would their more inflexible companions.

264. TO G.J. ROMANES. July 16th, 1874

I am much obliged for your kind and long communication, which I have read with great interest, as well as your articles in "Nature." The subject seems to me as important and interesting as it is difficult. I am much out of health, and working very hard on a very different subject, so thus I cannot give your remarks the attention which they deserve. I will, however, keep your letter for some later time, when I may again take up the subject. Your letter makes it clearer to me than it ever was before, how a part or organ which has already begun from any cause to decrease, will go on decreasing through so-called spontaneous variability, with intercrossing; for under such circumstances it is very unlikely that there should be variation in the direction of increase beyond the average size, and no reason why there should not be variations of decrease. I think this expresses your view. I had intended this summer subjecting plants to [illegible] conditions, and observing the effects on variation; but the work would be very laborious, yet I am inclined to think it will be hereafter worth the labour.

265. TO T. MEEHAN. Down, October 9th, 1874

I am glad that you are attending to the colours of dioecious flowers; but it is well to remember that their colours may be as unimportant to them as those of a gall, or, indeed, as the colour of an amethyst or ruby is to these gems. Some thirty years ago I began to investigate the little purple flowers in the centre of the umbels of the carrot. I suppose my memory is wrong, but it tells me that these flowers are female, and I think that I once got a seed from one of them; but my memory may be quite wrong. I hope that you will continue your interesting researches.

266. TO G. JAGER. Down, February 3rd, 1875

I received this morning a copy of your work "Contra Wigand," either from yourself or from your publisher, and I am greatly obliged for it. (266/1. Jager's "In Sachen Darwins insbesondere contra Wigand" (Stuttgart, 1874) is directed against A. Wigand's "Der Darwinismus und die Naturforschung Newtons und Cuviers" (Brunswick, 1874).) I had, however, before bought a copy, and have sent the new one to our best library, that of the Royal Society. As I am a very poor german scholar, I have as yet read only about forty pages; but these have interested me in the highest degree. Your remarks on fixed and variable species deserve the greatest attention; but I am not at present quite convinced that there are such independent of the conditions to which they are subjected. I think you have done great service to the principle of evolution, which we both support, by publishing this work. I am the more glad to read it as I had not time to read Wigand's great and tedious volume.

267. TO CHAUNCEY WRIGHT. Down, March 13th, 1875

I write to-day so that there shall be no delay this time in thanking you for your interesting and long letter received this morning. I am sure that you will excuse brevity when I tell you that I am half-killing myself in trying to get a book ready for the press. (267/1. The MS. of "Insectivorous Plants" was got ready for press in March, 1875. Darwin seems to have been more than usually oppressed by the work.) I quite agree with what you say about advantages of various degrees of importance being co-selected (267/2. Mr. Chauncey Wright wrote (February 24th, 1875): "The inquiry as to which of several real uses is the one through which Natural Selection has acted...has for several years seemed to me a somewhat less important question than it seemed formerly, and still appears to most thinkers on the subject...The uses of the rattling of the rattlesnake as a protection by warning its enemies and as a sexual call are not rival uses; neither are the high-reaching and the far-seeing uses of the giraffe's neck 'rivals.'"), and aided by the effects of use, etc. The subject seems to me well worth further development. I do not think I have anywhere noticed the use of the eyebrows, but have long known that they protected the eyes from sweat. During the voyage of the "Beagle" one of the men ascended a lofty hill during a very hot day. He had small eyebrows, and his eyes became fearfully inflamed from the sweat running into them. The Portuguese inhabitants were familiar with this evil. I think you allude to the transverse furrows on the forehead as a protection against sweat; but remember that these incessantly appear on the foreheads of baboons.

P.S.--I have been greatly pleased by the notices in the "Nation."

268. TO A. WEISMANN. Down, May 1st, 1875

I did not receive your essay for some days after your very kind letter, and I read german so slowly that I have only just finished it. (268/1. "Studien zur Descendenz-Theorie" I. "Ueber den Saison-Dimorphismus," 1875. The fact was previously known that two forms of the genus Vanessa which had been considered to be distinct species are only SEASONAL forms of the same species--one appearing in spring, the other in summer. This remarkable relationship forms the subject of the essay.) Your work has interested me greatly, and your conclusions seem well established. I have long felt much curiosity about season-dimorphism, but never could form any theory on the subject. Undoubtedly your view is very important, as bearing on the general question of variability. When I wrote the "Origin" I could not find any facts which proved the direct action of climate and other external conditions. I long ago thought that the time would soon come when the causes of variation would be fully discussed, and no one has done so much as you in this important subject. The recent evidence of the difference between birds of the same species in the N. and S. United States well shows the power of climate. The two sexes of some few birds are there differently modified by climate, and I have introduced this fact in the last edition of my "Descent of Man." (268/2. "Descent of Man," Edition II. (in one volume), page 423. Allen showed that many species of birds are more strongly coloured in the south of the United States, and that sometimes one sex is more affected than the other. It is this last point that bears on Weismann's remarks (loc. cit., pages 44, 45) on Pieris napi. The males of the alpine-boreal form bryoniae hardly differ from those of the German form (var. vernalis), while the females are strikingly different. Thus the character of secondary sexual differences is determined by climate.) I am, therefore, fully prepared to admit the justness of your criticism on sexual selection of lepidoptera; but considering the display of their beauty, I am not yet inclined to think that I am altogether in error.

What you say about reversion (268/3. For instance, the fact that reversion to the primary winter-form may be produced by the disturbing effect of high temperature (page 7).) being excited by various causes, agrees with what I concluded with respect to the remarkable effects of crossing two breeds: namely, that anything which disturbs the constitution leads to reversion, or, as I put the case under my hypothesis of pangenesis, gives a good chance of latent gemmules developing. Your essay, in my opinion, is an admirable one, and I thank you for the interest which it has afforded me.

P.S. I find that there are several points, which I have forgotten. Mr. Jenner Weir has not published anything more about caterpillars, but I have written to him, asking him whether he has tried any more experiments, and will keep back this letter till I receive his answer. Mr. Riley of the United States supports Mr. Weir, and you will find reference to him and other papers at page 426 of the new and much-corrected edition of my "Descent of Man." As I have a duplicate copy of Volume I. (I believe Volume II. is not yet published in german) I send it to you by this post. Mr. Belt, in his travels in Nicaragua, gives several striking cases of conspicuously coloured animals (but not caterpillars) which are distasteful to birds of prey: he is an excellent observer, and his book, "The Naturalist in Nicaragua," very interesting.

I am very much obliged for your photograph, which I am particularly glad to possess, and I send mine in return.

I see you allude to Hilgendorf's statements, which I was sorry to see disputed by some good German observer. Mr. Hyatt, an excellent palaeontologist of the United States, visited the place, and likewise assured me that Hilgendorf was quite mistaken. (268/4. See Letters 252-7.)

I am grieved to hear that your eyesight still continues bad, but anyhow it has forced your excellent work in your last essay.

May 4th. Here is what Mr. Weir says:--

"In reply to your inquiry of Saturday, I regret that I have little to add to my two communications to the 'Entomological Society Transactions.'

"I repeated the experiments with gaudy caterpillars for years, and always with the same results: not on a single occasion did I find richly coloured, conspicuous larvae eaten by birds. It was more remarkable to observe that the birds paid not the slightest attention to gaudy caterpillars, not even when in motion,--the experiments so thoroughly satisfied my mind that I have now given up making them."