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Darwin Correspondence Project

To G. H. K. Thwaites   19 May [1868]1

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

May 19th

My dear Thwaites

Many thanks for your note of April 1st— I see that the case of the monkeys is hopeless; & you must not take any more trouble about human expression.—2 About a month after writing to you I heard that the keepers at Zoolog. Gs. could make the Elephants trumpet; & whenever they did so loudly invariably they contracted the orbicularis palpebrarum. Moreover the keepers positively affirmed that they had several times seen tears running down cheeks when in distress. So I am well answered; but if you shd. receive any details I shd of course like to hear them.—3

And now I have another favour to beg, & I really will not trouble you again. Layard describes a breed of fowls in Ceylon, which offers the unique case of the Hens alone, being coloured as if “a white fowl had been drawn down a sooty chimney”. the roof of mouth, wattles &c deep-leaden blue & periosteum black.— The males have not these peculiarities.—4 Now it is of very great interest to me to know the characters of the young hens & cocks, in their first plumage, after they have shed the down. Are the hens in the first plumage sooty & have they black roofs to mouth & dark wattles? & what colour are the cocks in their first plumage?— Unless they differ from all other fowls, the first plumage will differ from the adult plumage, & as the hen here differs, it is of the greatest interest to me to understand the law of change.— Perhaps the breed is normally sooty & the cock alone becomes pure white in its adult state. Or does the hen change & become sooty when adult.—

I beg you to help me, if you can, & to forgive me if you can.—

Yours very sincerely | C. Darwin


The year is established by the relationship between this letter and the letter from G. H. K. Thwaites, 1 April 1868.
See letter from G. H. K. Thwaites, 1 April 1868. CD had asked Thwaites to observe whether monkeys that fought in confinement were protected by their manes and beards, and had sent him lists of queries about human expression to distribute (letters to G. H. K. Thwaites, 31 January [1868] and 13 February [1868]).
In his letter to Thwaites of 31 January [1868], CD had asked him to have someone observe whether violently screaming elephants contracted the muscles around the eye. See also letter to WEDarwin, [15 March 1868], and Expression, pp. 167–8. CD refers to the Zoological Gardens in Regent’s Park, London.
CD also mentioned Edgar Leopold Layard’s description of the Ceylon (Sri Lanka) fowl in Variation 1: 256, citing E. L. Layard 1853–4.


Expression: The expression of the emotions in man and animals. By Charles Darwin. London: John Murray. 1872.

Layard, Edgar Leopold. 1853–4. Notes on the ornithology of Ceylon, collected during an eight years’ residence in the island. Annals and Magazine of Natural History 2d ser. 12: 97–107, 165–76, 262–72; 13: 123–31, 212–18, 257–64, 446–53; 14: 57–64, 105–15, 264–72.

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


GHKT should not take more trouble about human expression. Discusses contraction of orbicular muscles in elephants.

Asks about colour of first plumage of breeds of Ceylon fowls in which hens alone are coloured.

Letter details

Letter no.
Charles Robert Darwin
George Henry Kendrick Thwaites
Sent from
Source of text
American Philosophical Society (Mss.B.D25.342)
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 6184,” accessed on 21 July 2024,

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