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Darwin Correspondence Project

From A. R. Wallace   12 July 1871

Holly House, Barking, E.

July 12th. 1871

Dear Darwin

Many thanks for giving me the opportunity to read at my leisure the very talented article of Mr C. Wright. His criticism of Mivart, though very severe, is, I think in most cases sound; but I find the larger part of the article so heavy and much of the language & argument so very obscure, that I very much doubt the utility of printing it separately.1 I do not think the readers of Mivart would ever read it in that form, and I am sure your own answers to Mivart’s arguments will be so much more clear & to the point, that the other will be unnecessary. You might extract certain portions in your own chapter such as the very ingenious suggestion as to the possible origin of mammary glands; as well as the possible use of the rattle of Rattlesnake &c.2

I cannot see the force of Mivarts objection to the theory of production long neck of Giraffe (suggested in my first Essay) & which C. Wright seems to admit, while his “watch tower” theory seems to me more difficult & unlikely as a means of origin. The argument—“why haven’t other allied animals been modified in the same way”?—seems to me the weakest of the weak.3

I must say also I do not see any great reason to complain of the “words” left out by Mivart as they do not seem to me materially to affect the meaning.4 Your expression “and tends to depart in a slight degree”, I think hardly grammatical;—a tendency to depart, cannot very well be said to be in a slight degree;—a departure can, but a tendency must be either a slight tendency or a strong tendency, the degree to which the departure may reach must depend on favourable or unfavourable causes in addition to the tendency itself. Mivart’s words “and tending to depart from the parental type” seem to me quite unobjectionable as a paraphrase of yours, because the “tending” is kept in;—and your own view undoubtedly is that the “tendency” may lead to an ultimate departure to any extent. Mivart’s error is, to suppose that your words favour the view of sudden departures, and I do not see that the expression he uses really favours his view a bit more than if he had quoted your exact words. The expression of yours he relies upon is evidently—“the whole organism seeming to have become plastic”—and he argues, no doubt erroneously, that having so become “plastic”,—any amount or a large amount of sudden variation in some direction is likely.—

Mivarts greatest error,—the confounding “individual variations” with “minute or imperceptible variations”—is well exposed by C. Wright5 & that part I should like to see reprinted,—but I always thought you laid too much stress on the slowness of the action of Nat. Select. owing to the smallness and rarity of favourable variations. In your chapter on Nat. Selectn. the expressions—“extremely slight modifications”—“every variation even the slightest”—“every shade of constitutional difference”—occur,—& these have led to errors such as Mivart’s.6 I say all this because I feel sure that Mivart would be the last to intentionally misrepresent you, and he has told me that he was sorry the word “infinitesimal”—as applied to the variations used by natural selection—got into his book, & that he would alter it, as no doubt he has done, in his second edition.7

Some of Mivart’s strongest points—the eye & ear, for instance,—are unnoticed in the Review. You will of course reply to these.8 His statement of the “missing link” argument is also forcible, & has I have no doubt much weight with the public.9 As to all his minor arguments, I feel with you, that they leave Nat. Selectn. stronger than ever,—while the two or three main arguments do leave a lingering doubt in my mind of some fundamental organic law of development of which we have as yet no notion.

Pray do not attach any weight to my opinions as to the “Review”. It is very clever,—but the writer seems a little like those critics who know an author’s or an artist’s meaning better than they do themselves.

My house is now in the hands of a contractor, but I am wall-building &c. & very busy.10 | With best wishes | Believe me Dear Darwin | Yours very faithfully | Alfred R. Wallace

CD annotations

1.1 Many … unnecessary. 1.7] crossed pencil
1.7 You might … &c. 1.9] scored pencil
2.1 I cannot … tower” 2.3] double scored blue crayon
5.1 Some … Review. 5.2] double scored blue crayon
6.1 Pray … busy. 7.2] crossed blue crayon


See letter to A. R. Wallace, 9 July [1871]. Wallace refers to Chauncey Wright’s review of St George Jackson Mivart’s Genesis of species (Wright 1871a, Mivart 1871b).
In Wright 1871a, pp. 92–3, Wright suggested that mammary glands might have originated from hypertrophied sebaceous glands, sucked on by an infant for some other reason, such as clinging on for protection. See also Origin 6th ed., pp. 189–90. In Wright 1871a, pp. 94–5, Wright suggested that the rattlesnake’s rattle, which seemed counterproductive as an aid to hunting, was used to warn predators, to fascinate victims, or to inspire the snake itself with courage, like a battle drum.
In his Contributions to the theory of natural selection (Wallace 1870), p. 42, Wallace argued that the long neck of the giraffe had been produced ‘because any varieties … with a longer neck than usual at once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the first scarcity of food were thereby enabled to outlive them.’ This was actually in the second essay in the book. Mivart had criticised the suggestion on the grounds that other Ungulata ought to have been modified the same way (Mivart 1871a, pp. 24–6). Wright had suggested that the giraffe’s neck was pre-eminently useful as a watchtower (Wright 1871a, p. 88). See also Origin 6th ed., pp. 177–9.
See Wright 1871a, p. 91.
For the quoted phrases, see Origin, pp. 83, 84, and 92.
Mivart changed most of the instances of ‘infinitesimal’ in the first edition of his Genesis of species (Mivart 1871a) to ‘insignificant’ or ‘minute’ in the second edition (Mivart 1871b).
CD added a quotation from Wallace to his remarks on the development of the eye in Origin 6th ed., p. 145, as part of his discussion of the problems for his theory of ‘Organs of extreme perfection and complication’ (ibid., pp. 143–6).
For Mivart’s remarks on the absence of transitional forms in the fossil record, see Mivart 1871a, pp. 128–36.
See letter from A. R. Wallace, 9 July [1871] and n. 8.


Origin 6th ed.: The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 6th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1872.

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.


Chauncey Wright’s article is sound, but so obscure ARW doubts utility of printing it separately.

Gives his own detailed analysis of Mivart’s attack.

Letter details

Letter no.
Alfred Russel Wallace
Charles Robert Darwin
Sent from
Source of text
DAR 106: B103–6
Physical description
8pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7861,” accessed on 2 December 2021,

Also published in The Correspondence of Charles Darwin, vol. 19