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Darwin Correspondence Project

To Edward Blyth   23 February [1867]1

Down. | Bromley. | Kent. S.E.

Feb 23.

My dear Mr Blyth

I have been very much interested by your remarks on the “Origin”; many of which are quite new to me, such as those on mimicry.2 I knew already some few of the other facts which you mention. I am thinking of writing a short essay on Man & have consequently been much struck with your remarks on the Orang. Do you know C. Vogt’s nearly similar remarks on the origin of Man from distinct Ape-families, founded on Gratiolet’s observations on the brain? I think you cannot object to my cautiously alluding to your observation on the similarity of the Orang & Malay &c: I think the similarity must be accidental, & I would confirm this by your observation on the S. American genus with respect to the Negro.3 I do not know what to think about the almost parallel case of Bats. If I had known that you wd have cared for a copy of the new Edit. of the Origin assuredly I wd have sent you one: you will of course receive my book on “Dom. Animals &c” whenever published.4 I regret much that I did not meet you in London, but during the two last days I was unable to leave the house.5

You gave me long since two printed pages Royal 8vo with a black line round the page with notes in very small type, it contains some excellent remarks on sexual plumage of birds evidently by yourself. Please to tell me the title that I may refer to it.6

I have picked up more facts on sexual characters, even when you are not discussing the subject from your writings than from those of any one else. Thus in the last No of “Land & Water” there is a notice which I am sure must be written by you, in which you indicate that the summer plumage of Gulls, Plovers &c is nuptial plumage common to both sexes like that confined to the Drake. This is a new idea to me, if I understand you rightly.— But I presume that you admit that winter plumage, as with the Ptarmigan, may be acquired for a special end.7

How I wish that you wd always sign your name to whatever you write. Can you guide me to any papers on sexual differences, especially in colour, in Mammals? I have picked out two cases by you on Bos & Antelopes in the “Indian Field”.8

Can you tell me whether the canine teeth differ in the sexes in the true Carnivora? But I must not ask any more questions except one:—Do you still maintain the law on sexual plumage in Birds as given in the sheets above referred to? Yarrell gives a rather different law, dependent on there being an annual change in plumage.9

But I have written to you at quite unreasonable length— pray forgive me & believe me yours very sincerely— | Ch. Darwin


The year is established by the relationship between this letter and the letter from Edward Blyth, 19 February 1867.
For Blyth’s remarks on the fourth edition of Origin, see the letter from Edward Blyth, 19 February 1867.
For CD’s intended publication on humans, see the letter to William Turner, 11 February [1867] and the letter to Fritz Müller, 22 February [1867] and n. 12. For Blyth’s comments on the orang-utan and on human resemblances to apes and monkeys, see the letter from Edward Blyth, 19 February 1867 and nn. 11 and 12. In Lectures on man (C. Vogt 1864, pp. 464–6), Carl Vogt discussed the three ‘ape-types’, the orang-utan, chimpanzee, and gorilla, and ways in which their features approached human features; in making these comparisons, he quoted Louis Pierre Gratiolet’s studies of cerebral structure. CD discussed Vogt’s idea in Descent 1: 230; he cited C. Vogt 1864 and referred to Gratiolet’s conclusions without citing their source, Gratiolet [1854]; CD did not allude to Blyth’s views. CD viewed the conclusions of Vogt and Gratiolet as unlikely (see Descent 1: 230–1). An annotated copy of C. Vogt 1864 is in the Darwin Library–CUL (see Marginalia 1: 824).
In his letter of 19 February 1867, Blyth sent comments on the fourth edition of Origin, and discussed resemblances between particular bat genera and primate groups. CD also refers to Variation, which was published in January 1868.
CD stayed at Erasmus Alvey Darwin’s home in London from 13 to 21 February 1867 (see letter to J. D. Hooker, 8 February [1867], n. 21); before falling ill, he had hoped to walk with Blyth in the Zoological Gardens, Regent Park (see letters to Edward Blyth, [18 February 1867] and [19 February 1867]).
CD also referred to these pages in his letter to Blyth of [18 February 1867]. They were galley proofs of a portion of Cuvier’s animal kingdom translated from Georges Cuvier’s Règne animal by Blyth (Cuvier 1840 or 1849 (new edition), pp. 158–9; these are pages 146 and 147 in Cuvier 1859 (reprint of the new edition)). The pages, annotated by both CD and Blyth, are in DAR 84.1: 179–80.
CD marked a passage mentioning the nuptial plumage of plovers, sandpipers, and some gulls and terns in the 16 February 1867 issue of Land and Water, p. 84; the annotated clipping entitled ‘Arrivals in the zoological gardens’ is in DAR 84.1: 182 and is not signed. CD wrote ‘Blyth’ at the bottom. He cited the article in Descent 2: 84 n. 77. CD discussed birds with similar plumage in both genders, even when moulting twice a year, in Descent 2: 80–6, with references to plovers, birds closely related to sandpipers, and the ptarmigan; see also ibid., pp. 180, 208–19.
CD made a general reference to Blyth’s observations of feral humped cattle (Bos indicus) in the Indian Field 1858, in Variation 1: 79 n. 33. CD cited Blyth, but not an article in the Indian Field, on colour differences in antelopes, in Descent 2: 288.
See n. 6 above. Blyth added editorial notes describing various sexual plumages according to different groups of species in Cuvier 1840 and 1849, pp. 158–9; in the last paragraph of the note on p. 159, he discussed the juvenile plumage in birds that undergo a double moult. In DAR 84.2: 2, CD listed ‘Blyths Laws (corrected)’; these include three laws of the plumage of juvenile birds in relation to the plumage of the adults. CD also refers to the third of three laws listed in William Yarrell’s A history of British birds (Yarrell 1843, 1: 159); this states that when adult birds assume breeding plumage different from winter plumage, the young birds’ plumage is intermediate ‘in the general tone of its colour’ between the winter and breeding plumage of the parent birds; his first two laws are on juvenile plumage in relation to sexual adult plumage. The first volume of Yarrell 1843 is in the Darwin Library–CUL and is heavily annotated, including the pages on sexual plumage (see Marginalia 1: 883–5). CD also wrote out six laws of plumage in his notes (see DAR 84.2: 3–4). In Descent 2: 186–223, CD listed the ‘classes of cases or rules under which the differences and resemblances, between the plumage of the young and the old, of both sexes or of one sex alone, may be grouped’.


Cuvier, Georges. 1840. Cuvier’s animal kingdom: arranged according to its organisation. Mammalia, birds, and reptiles by Edward Blyth. The fishes and radiata by Robert Mudie. The molluscous animals by George Johnston. The articulated animals by J. O. Westwood. London: Wm. S. Orr and Co.

Cuvier, Georges. 1859. The animal kingdom, arranged after its organisation … by the late Baron Georges Cuvier. Translated and adapted to the present state of science. Mammalia, birds, and reptiles by Edward Blyth. The fishes and radiata by Robert Mudie. The molluscous animals by George Johnston. The articulated animals by J. O. Westwood. A new edition with additions by W. B. Carpenter and J. O. Westwood. London and Edinburgh: A. Fullerton & Co. [Reprint of Cuvier 1849, with added plates.]

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

Gratiolet, Louis Pierre. [1854.] Mémoire sur les plis cérébraux de l’homme et des primatès. Paris: Arthus Bertrand.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

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.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Vogt, Carl. 1864. Lectures on man: his place in creation, and in the history of the earth. Edited by James Hunt. London: Longman, Green, Longman, and Roberts.


Many of EB’s remarks about Origin [4th ed. (1866)] are new to CD.

Thinks of writing a short essay on man.

Struck by EB’s remarks about orang. They are similar to Carl Vogt’s remarks on origin of man from distinct ape families.

Thinks similarity of orang to Malay must be accidental.

Will send Variation when it is published.

Letter details

Letter no.
Charles Robert Darwin
Edward Blyth
Sent from
Source of text
McGill University Library, Department of Rare Books
Physical description
LS(A) 7pp

Please cite as

Darwin Correspondence Project, “Letter no. 5413,” accessed on 1 June 2023,

Also published in The Correspondence of Charles Darwin, vol. 15