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Darwin Correspondence Project


To B. D. Walsh   9 July [1865]

Down Bromley | Kent

July 9

My dear Sir

I must send you a line to thank you for your interesting letter of May 29th.1

I have been ill during the last two months & have done no scientific work.

Many thanks for the case of Panagæus; this genus is almost sacred to me from old Cambridge recollections.2

Thanks also for the extract from Gen. Paez’ work.3 With respect to Daphnia it is a common genus of Entomostracan crustaceans4 & the facts to which you allude are well known, excepting the case, if true, of the males producing one form of eggs, which must I think have been discovered since I attended to the Genus.5

I sent you a few weeks ago a paper by me on climbing plants;6 but I doubt whether you will find it worth reading.

I am very much pleased that you like Bates’ paper.7 Pray read his Travels.8

Believe me | my dear Sir | yours very sincerely | Ch. Darwin


See letter from B. D. Walsh, 29 May 1865.
In his letter of 29 May 1865, Walsh told CD about two North American Panagaeus species with the same coloration as the Panagaeus crux-major that CD knew in Britain. CD often referred nostalgically to this particular beetle, especially in connection with an incident from his student days at Cambridge. He had spotted a P. crux-major while holding two other beetles, put one of the others in his mouth so that he could catch the P. crux-major, and ended up losing all three when the beetle in his mouth squirted acid down his throat (Correspondence vol. 3, letter to Leonard Jenyns, 17 October [1846], and Autobiography, pp. 62–3).
The reference is to Paez 1863. See letter from B. D. Walsh, 29 May 1865 and n. 18.
Walsh had asked CD what class Daphnia belonged to (see letter from B. D. Walsh, 29 May 1865). Entomostraca was the name used to refer to all crustaceans other than Malacostraca (Leftwich 1973). In modern classification Daphnia is in the class Branchiopoda, order Diplostraca, sub-order Cladocera.
See letter from B. D. Walsh, 29 May 1865 and n. 14. CD had last discussed the genus when John Lubbock sent him the manuscript of a paper on reproduction in Daphnia (Lubbock 1857) for comment (see Correspondence vol. 6, letter to John Lubbock, 27 October [1856]). CD did not publish on the genus.
The reference is to ‘Climbing plants’. No presentation list has been found.
The reference is to Bates 1861 (see letter from B. D. Walsh, 1 March 1865 and n. 30). Walsh’s comments on Bates 1861 must have been in one of the missing parts of his letter of 29 May 1865.
The reference is to The naturalist on the river Amazons (Bates 1863), which CD had encouraged Henry Walter Bates to write (see Correspondence vols. 9 and 10, and Bates 1863, 1: iv). CD was very enthusiastic about this work (see Correspondence vol. 11, letter to H. W. Bates, 30 April [1863]). CD’s annotated copy of Bates 1863 is in the Darwin Library–CUL (see Marginalia 1: 35–7).


Thanks BDW for his interesting letter [4839] and for the case of Panagaeus, a genus almost sacred to him since Cambridge days.

Letter details

Letter no.
Darwin, C. R.
Walsh, B. D.
Sent from
Source of text
Field Museum of Natural History, Chicago (Walsh 4)
Physical description
4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 4867,” accessed on 24 October 2016,