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Darwin Correspondence Project

To J. J. Weir   4 April [1868]

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

April 4th

My dear Sir

I read over your last ten(!) letters this morning & made an index of their contents for easy reference; & what a mine of wealth you have bestowed on me.—1 I am glad you will publish yourself on gay-coloured caterpillars & Birds: it seems to me much the best plan: therefore I will not forward your letter to Mr Wallace.2

I was much in Zoolog. Gardens during my month in London & picked up what scraps of knowledge I could: without my having mentioned your most interesting observations on the display of the Fringillidæ, Mr. Bartlett told me how the Gold Pheasant erects his collar & turns from side to side displaying it to the hen.3 He has offered to give me notes on the display of all Gallinaceæ with which he is acquainted; but he is so busy a man that I rather doubt whether he will ever do so.—4

I received about a week ago a remarkably kind letter from your Brother; & I am sorry to hear that he suffers much in health: he gave me some fine facts about a Dun Hen Carrier which would never pair with a Bird of any other colour. He told me, also, of some one at Lewes who paints his dog! & will enquire about it.5

By the way Mr Trimen tells me that as a Boy he used to paint Butterflies, & that they long haunted the same place; but he made no further observations on them.6

As far as colour is concerned, I see I shall have to trust to mere inference from the males displaying their plumage & other analogous facts.— I shall get no direct evidence of the preference of the hens.—

Mr Hewitt of Birmingham tells me that the common hen prefers a salacious cock, but is quite indifferent to colour.—7

Will you consider & kindly give me your opinion on the two following points. Do very vigorous & well nourished hens receive the male earlier in the Spring than weaker or poorer hens? I suppose that they do.—

Secondly, do you suppose that the birds which pair first in the season have any advantage in rearing numerous & healthy offspring over those which pair later in the season?

With respect to the mysterious cases, of which you have given me so many in addition to those previously collected, of when one bird of a pair is shot, another immediately supplying its place, I was drawing to the conclusion that there must be in each district several unpaired birds; yet this seems very improbable.— You allude, also, to the unknown causes which keep down the numbers of Birds; & often & often have I marvelled over this subject with respect to many animals.8

With sincere thanks | My dear Sir | Yours very faithfully | Charles Darwin


CD refers to ten letters from Weir dated between [after 27 February] 1868 and 31 March 1868.
Alfred Russel Wallace had asked Weir to carry out experiments to test Wallace’s theory that brightly coloured caterpillars would be refused by birds (see Correspondence vol. 15, letter from A. R. Wallace, 24 February [1867] and n. 4). After receiving Weir’s preliminary results (letter from J. J. Weir, 24 March 1868), CD had asked whether he should forward Weir’s letter to Wallace, but Weir replied that he planned to do further experiments and publish the results (see letter to J. J. Weir, 27 March [1868], and letter from J. J. Weir, 31 March 1868 and n. 4). In Descent 1: 417, CD reported Weir’s experiments and cited his first paper on the subject (Weir 1869).
CD was in London from 3 March to 1 April 1868 (see ‘Journal’ (Correspondence vol. 16, Appendix II)). In a note dated 28 March, CD cited Abraham Dee Bartlett of the Zoological Gardens, Regent’s Park: ‘Mr Bartlett … instanced the Gold pheasant which exhibits his splendid frill & turns from side to side before female bird.’ (DAR 84:2: 198.) For Weir’s description of display in members of the Fringillidae, see the letter from J. J. Weir, 11 March 1868.
The order Gallinaceae included fowls, pheasants, and quail, and was roughly equivalent to the modern order Galliformes. In Descent 2: 89 and 93, CD included information from Bartlett on display in the gallinaceous genus Polyplectron and on the absence of male display in some dull-coloured pheasant species.
See letter from H. W. Weir, 28 March 1868. Dun Hen Carrier: a female dun-coloured pigeon. The information on the pigeon is cited in Descent 2: 118.
Roland Trimen visited CD in London on 25 March 1868 (see letter to Roland Trimen, [21 March 1868]).
See letter from Edward Hewitt, 28 March 1868. In Descent 2: 117, CD cited Hewitt on the indifference of female birds to the beauty of male plumage.
See letters from J. J. Weir, 7 March 1868, 23 March 1868, and 31 March 1868.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

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

Weir, John Jenner. 1869. On insects and insectivorous birds; and especially on the relation between the colour and the edibility of Lepidoptera and their larvae. [Read 1 March 1869.] Transactions of the Entomological Society of London (1869): 21–6.


CD thanks JJW for the mine of information his last "ten!" letters contain. Comments on sexual display of pheasants and colour preferences of pigeons.

Asks about hens that pair earliest in spring and about possible existence of unpaired birds.

Letter details

Letter no.
Charles Robert Darwin
John Jenner Weir
Sent from
AP 5 68
Source of text
American Philosophical Society (Mss.B.D25.)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6090,” accessed on 6 December 2021,

Also published in The Correspondence of Charles Darwin, vol. 16