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Darwin Correspondence Project

To Henry Denny   [27 July – 10 August 1844]1

Down Bromley Kent


Dear Sir

I herewith send you the four little packets of Lice.—2 I remember thinking that one, though minute, was an odd form.—

I sincerely wish I could aid you in obtaining fresh materials: should I have any opportunity, I will not fail to remember to ask anyone, whom I may meet & think likely to have specimens: but I live so retired in the country, that I now see few naturalists. Have you ever applied to Dr. A. Smith, (Fort Pitt Chatham) the S. African Traveller, if you like to write to him, you can use my name & say, I was sure that he would be glad to assist every naturalist.3

I am sorry to say I shall not be at York,4 otherwise you might depend on my aid, feeble though it would be.

With my best wishes for success in your laborious pursuit.5 Pray believe me | dear Sir | yours very faithfully | C. Darwin

P.S I have kept no copy of the extract of ‘White’s Regular Gradation in Man’—a foolish book with some odd facts—published, I think, at Manchester. You wd easily find the passage to which I refer.— I think it was in the latter part of the volume.—6

The next time I write to Dr Hooker I will ask him, whether he has Lice of Penguins.—7

I find I can make the bottle safe, so will send it by Post at same time with this note.— The bottle shd be opened, as it is not quite full— the spirits are quite strong enough

C. D


The date is established by CD’s offer in this letter to write to Joseph Dalton Hooker and ask whether he had specimens of penguin lice, and by the fact that CD responded to Denny’s queries about the specimens sent with this letter in his letter to Denny of 12 August [1844] (Correspondence vol. 3). In 1844, the last Saturday before 12 August was 10 August, the latest possible date for this letter. CD wrote to Hooker mentioning Denny’s request for penguin lice in a letter originally published in Correspondence vol. 3 with the date [25 July – 29 August 1844]. The nearest extant letter from CD to Hooker before this one is dated 22 July [1844] (Correspondence vol. 3), and does not mention Denny or penguin lice. In 1844, the first Saturday after 22 July was 27 July, the earliest possible date for this letter. The letter to Hooker mentioning Denny’s request for penguin lice, which was written on a Thursday, should therefore be dated [1–29 August 1844], 1 August being the first Thursday after 27 July.
For identification of these packets see Correspondence vol. 3, letter to Henry Denny, 12 August [1844]. Denny had requested specimens of lice from CD in January 1844 (see ibid., letter to Henry Denny, 20 January [1844]), but CD was unable to send any until July, when he had sorted his collections (see ibid., letter to Henry Denny, 3 June [1844] and n. 2).
Andrew Smith was an army surgeon and an authority on South African zoology (DNB). CD had become acquainted with him in June 1836 at the Cape of Good Hope (see Correspondence vol. 1, letter to J. S. Henslow, 9 July 1836, and Appendix I).
The British Association for the Advancement of Science met in York from 26 September to 2 October 1844 (Report of the fourteenth meeting of the British Association for the Advancement of Science, held at York in September 1844, p. xxx).
Denny, at the request of the Natural History Section of the British Association for the Advancement of Science, had undertaken to investigate and illustrate exotic species of Anoplura (Report of the fourteenth meeting of the British Association for the Advancement of Science, held at York in September 1844, p. 392). He had already published an account of the British Anoplura (Denny 1842).
CD read C. White 1799 in May or June 1844 (see CD’s reading notebooks, Correspondence vol. 4, Appendix IV, 119: 14a). The book was compiled from papers read to the Literary and Philosophical Society of Manchester in 1795, and published in London. Lice are mentioned on page 79: Mr. Long takes notice of a fact, which seems to have escaped the observation of naturalists:—that the lice which infest the bodies of negroes are blacker, and generally larger, than those which are found on white people.
See Correspondence vol. 3, letter to J. D. Hooker, [25 July – 29 August 1844] (for the correction to the date of this letter, see n. 1, above).


Sends four packets of lice and suggests writing to Dr A. Smith, "the S. African traveller", for assistance.

Letter details

Letter no.
Charles Robert Darwin
Henry Denny
Sent from
Source of text
Yale University Medical Historical Library, Harvey Cushing / John Hay Whitney Medical Library (MMS)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 763F,” accessed on 23 September 2020,

Also published in The Correspondence of Charles Darwin, vol. 13 (Supplement)