To B. D. Walsh   21 September 1868

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

Sep 21 1868

My dear Sir

I am very sorry that my book has never reached you, & so is Mr Murray, & he has proved his sorrow by sending off at his own cost by post this day another copy.1

I have much to thank you for: I have been glad to see Dr Scudder’s pamphlet (returned by this post) though it does not contain much.2

Judge Caton’s pamphlet is really admirable, & I have found in it much useful for my work.3

Pray thank Mr Riley for the extract about the peach trees. I have much pleasure in enclosing my photograph for him; but I do not like to take the liberty of applying to Prof. Westwood for his photograph.4

I am particularly obliged for your information about the stridulating organs; these certainly sometimes differ in the two sexes, but how far this is general I am unable to say.5

Your investigation about the Cicadas possesses extraordinary interest & the map will be a curiosity. How odd it is that individuals do not migrate from one area into another, & thus cause apparent confusion in the periods.6

I see that Scudder states that the Orthoptera stridulate differently by night & day; may not the “forced” Cicadas be dumb from coming out when the average temperature is too low;7 it wd be curious to ascertain whether the dumb individuals can breed.

With most sincere thanks for all your kindness— Believe me yours very truly | Ch. Darwin

LS(A)

2
CD refers to a work by Samuel Hubbard Scudder on the stridulating organs of Orthoptera (Scudder 1867; see letter from B. D. Walsh, 29 August 1868 and n. 14). CD used information from Scudder’s paper in Descent 1: 353, 356, and 2: 331; CD mistakenly cited it as being from the April 1868 issue of the periodical, rather than from the October 1867 number (see Scudder 1867).
3
For CD’s use of Caton 1868, sent to him by Walsh, see the letter to J. D. Caton, 18 September 1868 and nn. 2–5.
4
For Charles Valentine Riley’s article on peach trees, see the enclosure to the letter from B. D. Walsh, 29 August 1868; Walsh had also asked whether CD could send Riley both his photograph and John Obadiah Westwood’s.
5
See letter from B. D. Walsh, 29 August 1868. For more on CD’s recent investigations into stridulating organs, see the letter to A. R. Wallace, 16 September [1868] and nn. 2 and 3.
7
Scudder wrote that the day and night songs were different only in some species; see Scudder 1867, pp. 309–10, for the differing songs. On the ‘forced’ cicadas, see the letter from B. D. Walsh, 29 August 1868.

Manuscript Alterations and Comments

7.3 dumb … Darwin 8.2] in CD’s hand

Please cite as “DCP-LETT-6382,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-6382