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Darwin Correspondence Project

To W. H. Harvey   [20–4 September 1860]1


My dear Sir

I have read your long letter with much interest & I thank you sincerely for your great liberality in sending it me.—2 But on reflexion I do not wish to attempt answering any part, except to you privately: anything said by myself in defence would have no weight; it is best to be defended by others or not at all.

Parts of your letter seem to me, if I may be permitted to say so, very acute & original; & I feel it a great compliment your giving up so much time to my book. But on the whole I am disappointed; not from your not concurring with me, for I never expected that; & indeed in your remarks on Ch. XII & XIII you go so much further with me, (though a little way) than I ever anticipated & am much pleased at the result. But on the whole I am disappointed, because it seems to me that you do not understand what I mean by Natural Selection, as shown at p. 11 of your letter & by several of your remarks.—   As my book has failed to explain my meaning it would be hopeless to attempt it in a letter. You speak in early part of your letter & at p. 9. as if I had said that Natural Selection was the sole agency of modification; whereas I have over & over again, ad nauseam, directly said & by order of precedence implied (what seems to me obvious) that selection can do nothing without previous variability. see p. 80, 108, 127, 468, 469 &c “Nothing can be effected unless favourable variations occur”. I consider Natural Selection as of such high importance, because it accumulates successive variations in any profitable direction; & thus adapts each new being to its complex conditions of life.—   The term “Selection” I see deceives many persons; though I see no more reason why it should than elective affinity, as used by the old chemists. If I had to rewrite my book, I would use “natural preservation” or “naturally preserved”. I shd. think you would as soon take an emetic as reread any part of my Book, but if you did & were to erase selection & selected & insert preservation & preserved, possibly the subject would be clearer.

As you are not singular in misunderstanding my Book, I should long before this have concluded that my brains were in a haze, had I not found by published reviews & especially by correspondence that Lyell, Hooker, Asa Gray, H. C. Watson, Huxley & Carpenter & many others perfectly comprehend what I mean.3

The upshot of your remarks at p. 11 is that my explanations &c & the whole doctrine of natural selection are mere empty words signifying the “order of nature”; as the above named clear-headed men, who do comprehend my views, all go a certain length with me & certainly do not think it all moonshine, I should venture to suggest a little further reflexion on your part. I do not mean by this to imply that the opinion of these men is worth much as showing that I am right, but merely as some evidence that I have clearer ideas, than you think; otherwise these same men must be even more muddled headed than I am; for they have no temptation to deceive themselves. In the forthcoming September nor of the American Journal of Science there is an interesting & short Theological Arcticle (by Asa Gray),4 which gives incidentally with admirable clearness the theory of Natural Selection, & therefore might be worth your reading: I think that the theological part would interest you.)

You object to all my illustrations: they are all necessarily conjectural, & may be all false; but they were the best I could give. The Bear case has been well laughed at, & disingenuously distorted by some into my saying that a bear could be converted into a whale; as it offended persons I struck it out in 2d. Edition; but I still maintain that there is no especial difficulty in a Bear’s mouth being enlarged to any degree useful to its changing habits,—no more difficulty than man has found in increasing the crop of the pigeon, by continued selection, until it is literally as big as whole rest of body. If this had not been known, how absurd it would have appeared to say that the crop of a bird might be increased till it became like a balloon.

(With respect to the ostrich, I believe that the wings have been reduced & are not in course of development, because the whole structure of a Bird is essentially formed for flight; & the Ostrich is essentially a bird. You will see at p. 182 of “Origin” a somewhat analogous discussion. At p. 450 of 2d Edit. I have pointed out the essential distinction between a nascent & rudimentary organ.—   If you prefer the more complex view that the progenitor of the Ostrich lost its wings, & that the present ostrich is regaining them, I have nothing to say in opposition.—)

(With respect to Trees on islands: I collected some cases, but took the main facts from Alph. De Candolle, & thought they might be trusted.5 My explanation may be grossly wrong; but I am not convinced it is so; & I do not see the full force of your argument of certain herbaceous orders having been developed into trees in certain rare cases on continent. The case seems to me to turn altogether on the question whether generally herbaceous orders more frequently afford trees & bushes on islands, than on continents, relatively to these areas.—)

(In p. 4. of your letter you say you give up many Book-species as separate creations; I give up all, & you infer that our difference is only in degree & not in kind. I dissent from this; for I give a distinct reason how far I go in giving up species; I look at all forms, which resemble each other homologically or embryologically as certainly descended from the same parents.)

(You hit me hard & fairly about my question (p. 483 Origin) about creation of eggs or young &c—(but not about mammals with mark of umbilical chord).6 Yet I still have an illogical sort of feeling that there is less difficulty in imagining the creation of an asexual cell, increasing by simple division.)

(Page 5 of your letter,—   I agree to every word about antiquity of World; & never saw the case put by any one more strongly or more ably. It makes, however, no more impression on me, as an objection; than does the astronomer when he puts on a few hundred-million miles to the distance of the fixed stars. To compare very small things with great,—Lingula &c remaining nearly unaltered from Silurian epoch to present day is like the dovecot pigeons still being identical with wild rock-pigeons, whereas its “fancy” offspring have been immensely modified & are still being modified by means of artificial Selection.)—)

(You put the difficulty of the first modification of the first protozoon admirably: I assure you that immediately after 1st. Edit. was published this occurred to me; & I thought of inserting it in 2d. Edit. I did not, because we know not in the least what the first germ of life was; nor have we any fact at all to guide us in our speculations on the kind of change which its offspring underwent. I dissent quite from what you say of myriads of years it would take to people world with such imagined protozoon.— In how very short a time Ehrenberg calculated that a single infusorium might make a cube of rock—7 A single cube on geometrical progression would make the solid globe in (I suppose) under a century. From what little I know I, cannot help thinking that you underrate the effect of the physical conditions of life on these low organisms. But I fully admit that I can give no sort of answer to your objection; yet I must add that it would be marvellous if any man ever could, assuming for the moment that my theory is true.—   You beg the question, I think, in saying that Protococcus would be doomed to eternal similarity:—nor can you know that the first germ resembled a Protococcus or any other now living form.—)

(Page 12 of your letter. There is nothing in my theory necessitating in each case progression of organisation; though natural selection tends in this line, & has generally thus acted. An animal if it became fitted by selection to live the life, for instance, of a parasite, will generally become degraded. I have much regretted that I did not make this part of the subject clearer; I left out this & many other subjects, which I now see ought to have been introduced. I have inserted a discussion on this subject in the foreign Editions.8 In no case will any organic being tend to retrograde unless such retrogradation be an advantage to its varying offspring; & it is difficult to see how going back to the structure of the unknown supposed original protozoon would ever be an advantage.)

(Page 13 of your letter. I have been more glad to read your discussion on “dominant” forms than any part of your letter:9 I can now see that I have not been cautious enough in confining my definition & meaning. I cannot say that you have altered my views. If Botrytis had exterminated the wild Potatoe, a low form would have conquered a high; but I cannot remember that I have ever said (I am sure I never thought) that a low form would never conquer a high. I have expressly alluded to parasites half exterminating game-animals: & to the struggle for life being sometimes between forms as different as possible, for instance between grasshoppers & herbivorous quadrupeds. Under the many conditions of life which this world affords, any group which is numerous in individuals & species & is widely distributed may properly be called dominant. I never dreamed of considering that any one group, under all conditions & throughout the world, could be pre dominant. How could Vertebrata be predominant, under the conditions of life to which parasitic worms live? What good would their perfected senses & their intellect serve under such conditions? When I have spoken of dominant forms, it has been in relation to the multiplication of new specific forms, & the dominance of any one species has been relative generally to other members of the same group, or at least to beings exposed to similar conditions & coming into competition. But I daresay that I have not in the Origin made myself clear, & space has rendered it impossible. But I thank you most sincerely for your valuable remarks, though I do not agree with them.)

(About sudden jumps;10 I have no objection to them: they would aid me in some cases: all I can say is, that I went into the subject, & found no evidence to make me believe in jumps; & a good deal pointing in the other direction.—   You will find it difficult (p. 14 of your letter) to make a marked line of separation between fertile & infertile crosses. I do not see how the apparently sudden change (for the suddenness of change in chrysalis is of course largely only apparent) in larvæ during their development throws any light on this subject.—)

I wish I could have made this letter better worth sending to you: I have had it copied to save you at least the intolerable trouble of reading my bad hand-writing. Again I thank you for your liberality & kindness in sending me your criticisms; & I heartily wish we were a little nearer in accord, but we must remain content to be as wide asunder as the poles; but without, thank God, any malice or other ill feeling.—

My dear Sir | Yours very sincerely

CD note:11

Every group of being which is great in number & widely distributed is dominant in Harveys sense & truly so, but *in relation of the multiplication of new species, [interl] I have always been referring to dominance over other members of the same group, & which in many, perhaps all [under del ‘most’] cases; implies the withstanding better the attacks of *various enemies, [interl] parasitic animals & plants & *insects too [interl] & ultimately tends [o make, in as far as' del] if many new species are produced, to make the groups thus increased by so far more dominant in the region under consideration.

It wd be more correct to speak of parasites as enemies, or as unfavourable conditions like cold or heat rather than as competitors or as concerned in struggle for life.— The competition is rather between allied forms which can best withstand such enemies.—


The text has been taken from a draft of the letter in DAR 98 (ser. 2): 45–53. The draft was probably composed over several days. The earliest possible date on which it could have been written was 20 September 1860, when CD composed lengthy notes pertaining to Harvey’s letter (see letter from W. H. Harvey, 24 August 1860, CD notes). It was completed by 24 September, for on that day he sent the manuscript to his copyist Ebenezer Norman with instructions to make a clean copy (see letter to Ebenezer Norman, [24 September 1860]).
At this point in the draft, CD wrote and then deleted: ‘These men who are clear-headed men, all go to some length with me; & I would ask you to pause before’.
CD refers to [Gray] 1860c.
In Origin, p. 392, CD cited Alphonse de Candolle as the authority for his statement that trees had restricted geographical ranges. CD postulated that trees would not be likely to colonise isolated islands and that those found on islands were usually arborescent forms of herbaceous orders. The reference was taken from A. de Candolle 1855, 1: 527–32. CD’s annotated copy of the work is in the Darwin Library–CUL.
In Origin, p. 483, CD asked of those who believed in miraculous acts of creation: ‘Do they believe that at each supposed act of creation one individual or many were produced? Were all the infinitely numerous kinds of animals and plants created as eggs or seed, or as full grown? and in the case of mammals, were they created bearing the false marks of nourishment from the mother’s womb?’
Ehrenberg 1854–6, pp. viii–ix. Christian Gottfried Ehrenberg, the founder of micropalaeontology in Germany, had corresponded with CD from 1844 to 1846 concerning samples of earth CD had taken from various countries visited on the Beagle voyage. Ehrenberg described the protozoa he found in these samples in Ehrenberg 1854–6, pp. 289–95.
The discussion was included in the revised American edition of Origin (pp. 116*–21*) and in the German translation (Bronn trans. 1860, pp. 133–7). See letters to Asa Gray, 28 January [1860], and to H. G. Bronn, 14 February [1860]. See also Appendix IV.
See CD’s note, above.
The note is in DAR 98 (ser. 2): 44. CD marked it in brown crayon: ‘Ch IV    Keep—’. He refers to chapter 4, on ‘Variation under nature’, of his ‘big book’ on species (Natural selection, pp. 95–171). CD also wrote in ink: ‘& p. 8 of my letter to Harvey’. He marked the first paragraph with square brackets in brown crayon. The page of Harvey’s letter to which CD refers discusses the problem of ‘dominant’ forms.


Candolle, Alphonse de. 1855. Géographie botanique raisonnée ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle. 2 vols. Paris: Victor Mason. Geneva: J. Kessmann.

Natural selection: Charles Darwin’s Natural selection: being the second part of his big species book written from 1856 to 1858. Edited by R. C. Stauffer. Cambridge: Cambridge University Press. 1975.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.


Replies to WHH’s criticisms of the Origin. Is disappointed that WHH does not understand what CD means by natural selection. CD has said "ad nauseam" that selection can do nothing without previous variability. Natural selection accumulates successive variations in any profitable direction. If CD had to rewrite his book he would use "natural preservation" rather than selection. Defends his necessarily conjectural illustrations. Agrees with what WHH says on the antiquity of the world, but it makes no impression on him. Considers the difficulty of the first modification of the first protozoan. Emphasises that there is nothing in his theory "necessitating in each case progression of acquisition", nor is it the case that "a low form would never conquer a high" in the struggle for life. Attempts to explain what he means by a "dominant" group; dominance is always relative, and he does not believe any one group could be predominant. He has no objections to "sudden jumps"; they would aid him in some cases, but he has found no evidence to make him believe in them and a good deal pointing the other way.

Letter details

Letter no.
Charles Robert Darwin
William Henry Harvey
Sent from
Source of text
DAR 98 (ser. 2): 45–53
Physical description
ADraft 10pp

Please cite as

Darwin Correspondence Project, “Letter no. 2922,” accessed on 20 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 8