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Darwin Correspondence Project

To H. W. Bates   20 November [1862]1

Down Bromley Kent

Nov. 20th

Dear Bates

I have just finished after several reads your Paper.2 In my opinion it is one of the most remarkable & admirable papers I ever read in my life. The mimetic cases are truly marvellous & you connect excellently a host of analogous facts. The illustrations are beautiful & seem very well chosen; but it would have saved the reader not a little trouble, if the name of each had been engraved below each separate figure;3 no doubt this would have put the engraver4 into fits, as it would have destroyed beauty of Plate. I am not at all surprised at such a paper having consumed much time. I rejoice that I passed over whole subject in the Origin, for I shd. have made a precious mess of it.5 You have most clearly stated & solved a wonderful problem.—

No doubt with most people this will be the cream of the paper; but I am not sure that all your facts & reasoning on variation & on the segregation of complete & semi-complete species is not really more, or at least as valuable a part.—6 I never conceived the process nearly so clearly before; one feels present at the creation of new forms.— I wish, however, you had enlarged a little more on the pairing of similar varieties; a rather more numerous body of facts seems here wanted.7

Then again what a host of curious miscellaneous observations there are,—as on related sexual & individual variability you give; these will some day, if I live, be a treasure to me.—8

With respect to mimetic resemblance being so common with insects; do you not think it may be connected with their small size; they cannot defend themselves;— they cannot escape by flight at least from Birds; therefore they escape by trickery & deception?9

I have one serious criticism to make & that is about title of paper; I cannot but think that you ought to have called prominent attention in it to the mimetic resemblances.—10 Your paper is too good to be largely appreciated by the mob of naturalists without souls; but rely on it, that it will have lasting value, & I cordially congratulate you on your first great work. You will find, I shd. think, that Wallace will fully appreciate it.—11

How gets on your Book?—12 Keep your spirits up. A Book is no light labour. I have been better lately & working hard; but my health is very indifferent. How is your health?

Believe me Dear Bates | Yours very sincerely | Ch. Darwin

Excuse my poor M.S. paper.—


The year is established by the relationship to the letter from H. W. Bates, 24 November 1862.
Bates 1862a appeared in the third part of volume 23 of the Transactions of the Linnean Society of London, which was published on 13 November 1862 (Raphael 1970); there is a copy of this part of the journal in the Darwin Library–CUL, in which Bates’s paper is heavily annotated.
The two colour plates of Amazonian mimetic butterflies published in Bates 1862a (plates LV and LVI), were keyed by numbers to identifications and descriptions at the end of the paper (pp. 564–6). CD added the species names to the figures in his copy of the paper.
The plates were drawn and engraved by Edward W. Robinson, a noted entomological artist.
In his paper, Bates invoked the theory of natural selection to account for the phenomenon of mimicry in Amazonian butterflies, arguing that the case offered ‘a most beautiful proof of the truth of the theory’ (Bates 1862a, p. 513). CD included a summary of Bates’s findings in the fourth edition of Origin, published in 1866 (Origin 4th ed., pp. 502–6).
In the introduction to his paper, Bates argued that ‘many of the now distinct species of Heliconidæ have arisen from local varieties, segregated from the variations of preexisting widely disseminated species’ (Bates 1862a, p. 501). In particular, he noted that in some species the varieties presented ‘all the different grades between simple individual differences and well-marked local varieties or races, which latter cannot be distinguished from true species, when two or more of them are found coexisting in the same locality without intercrossing’. For the details of these cases, Bates referred the reader to his systematic descriptions of the various species (pp. 515–64). See also letter to J. D. Hooker, 18 [November 1862] and n. 11.
In Bates 1862a, p. 501, Bates stated: The process of the creation of a new species I believe to be accelerated in the Ithomiæ and allied genera by the strong tendency of the insects, when pairing, to select none but their exact counterparts: this also enables a number of very closely allied ones to exist together, or the representative forms to live side by side on the confines of their areas, without amalgamating. In his copy of the paper, CD wrote at this point ‘What proof?’, but added ‘See further on’. Bates’s reply has not been found, but see the letter to H. W. Bates, 15 December [1862].
See, for example, Bates 1862a, p. 502. CD frequently cited Bates’s work in his account of sexual selection in insects in Descent 1: 309–15 and 341–423; however, he did not cite this paper.
In Bates 1862a, p. 507, Bates noted: It may be asked, why are mimetic analogies so numerous and amazingly exact in insects, whilst so rare and vague in the higher animals? The only answer that I can suggest is, that insects have perhaps attained a higher degree of specialization, after their type, than most other classes: this seems to be shown by the perfection of their adaptive structures and instincts. In Origin 4th ed., p. 506, following his discussion of Bates’s work on mimicry, CD suggested that the ‘much greater frequency of mockery with insects than with other animals’ was ‘probably the consequence of their small size’, and continued: insects cannot defend themselves, excepting indeed the kinds that sting, and I have never heard of an instance of these mocking other insects, though they are mocked: insects cannot escape by flight from the larger animals; hence they are reduced, like most weak creatures, to trickery and dissimulation.
Bates’s paper was entitled: ‘Contributions to an insect fauna of the Amazon Valley. Lepidoptera: Heliconidæ.’ See also letter to J. D. Hooker, 18 [November 1862] and n. 12.
Bates and Alfred Russel Wallace were close friends, and had travelled together to South America in 1848 (see, for example, Wallace 1905). In his paper, Bates cited an instance of bird mimicry communicated to him by Wallace (Bates 1862a, p. 507 n.).


Bates, Henry Walter. 1862. Contributions to an insect fauna of the Amazon valley. Coleoptera: Longicornes. Annals and Magazine of Natural History 3d ser. 9: 117–24, 396–405, 446–58.

Bates, Henry Walter. 1863. The naturalist on the River Amazons. A record of adventures, habits of animals, sketches of Brazilian and Indian life, and aspects of nature under the equator, during eleven years of travel. 2 vols. London: John Murray.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

Origin 4th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 4th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1866.

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.

Raphael, Sandra. 1970. The publication dates of the Transactions of the Linnean Society of London, series 1, 1791–1875. Biological Journal of the Linnean Society 2: 61–76. [Vols. 10,11]

Wallace, Alfred Russel. 1905. My life: a record of events and opinions. 2 vols. London: Chapman & Hall.


Just finished HWB’s paper ["Contributions to an insect fauna of the Amazon valley", Trans. Linn. Soc. Lond. 23 (1862): 495–566], one of the most remarkable he has ever read. Found mimetic cases and connection of facts marvellous. Finds equally important the facts on variation and segregation of complete and semi-complete species. Questions whether insect mimicry is not due to small size and defencelessness. Criticises title of paper. Mentions that Wallace will appreciate it.

Letter details

Letter no.
Charles Robert Darwin
Henry Walter Bates
Sent from
Source of text
Cleveland Health Sciences Library (Robert M. Stecher collection)
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 3816,” accessed on 17 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 10