From W. F. Kirby 8 September [1863]
29 Nelson Terrace | New Hampstead Road | NW
Sept 8
Dear Sir
I must apologize for not answering your letter of July 9th long before, but I was unable to attend the August meeting of the Entomological Society, and consequently never received it till yesterday.1 I am very glad you approve of my paper, but it is a very imperfect sketch for want of more extensive materials.2 There is a slight error in my remarks on the genus Papilio, as the number of described species is (in round numbers) not 300 but 400.3 I think Mr Wallace once remarked to me that the depth of the sea between Corsica and Sardinia and the main land of Italy proved that they had long been separated.4 Mr Doubleday5 tells me that Coenonympha Typhon (which I regard as a distinct species from C. Davus, though he does not) gradually becomes paler and paler as it advances north till in Scandinavia and the northern islands of Scotland it is almost white and immaculate forming the variety Isis of Thunberg.6 And there is a whitish Coenonympha nearly related to this in the British Museum from California. C Davus (or rather C Typhon I imagine, which is the commoner form) occurs in Amoorland.
On referring to Menetries I find that two or three forms of Isis occur in Amoorland, and after examining a large number of specimens, he is of opinion that it is only a northern form of Davus (Typhon)7 I think Mr Doubleday once told me that Isis occurred in Iceland, but I am not certain. The most perplexing question in the geographical distribution of butterflies is how to account for that of Pyrameis Atalanta and Callirhoe. I suppose that while Atalanta, a species of gigantic power like all of its genus was establishing itself on the continent of Europe and Africa, the Canaries were separated from the mainland so as to prevent its crossing over and crushing out Callirhoe. I had suggested this in my paper, but struck it out at the suggestion of Mr Bates who kindly looked it over before I read it, and thought the hypothesis too fanciful.8 Still this would not account for the occurrence of Atalanta in North America, as I have no evidence of its having occurred east of Asia Minor, and if it occurred in Siberia, such a conspicuous insect must have found its way into some of the excellent Russian works on the Lepidoptera of Northern Asia. To be sure Cramer says that it occurs in China,9 but if it occurs in Northern Asia at all, it must be very rare, and no dependence whatever can be placed in localities given for insects by the old authors, some of whom used the phrase “ab Indiis” as equivalent to “exotic”10
With every wish for the success of your series of works on species,11 | Believe me, dear Sir | Yours very truly | W. F. Kirby
PS Mr F. Smith12 will tell you there is a humble-bee (Bombus Smithianus) peculiar to the northern Islands of Scotland I forget which
CD annotations
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Index animalium: Index animalium sive index nominum quae ab @A.D. MDCCLVIII@generibus et speciebus animalium imposita sunt. By Charles Davies Sherborn. 10 vols. Cambridge: Cambridge University Press. London: British Museum. 1902–32. [Vols. 10,11]
Kirby, William Forsell. 1863. On the geographical distribution of European Rhopalocera. [Read 5 January 1863.] Transactions of the Entomological Society of London 3d ser. 1 (1862–4): 481–91.
Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.
Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.
Summary
Describes some cases of geographical distribution of butterflies. Raises the perplexing question of the distribution of Pyrameis atalanta in Europe and P. calliroe in the Canaries.
Letter details
- Letter no.
- DCP-LETT-4297
- From
- William Forsell Kirby
- To
- Charles Robert Darwin
- Sent from
- London, New Hampstead Rd
- Postmark
- London. W.C. 6 SP 9 63
- Source of text
- DAR 205.3 (Letters): 280
- Physical description
- ALS 5pp †
Please cite as
Darwin Correspondence Project, “Letter no. 4297,” accessed on 26 November 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-4297.xml
Also published in The Correspondence of Charles Darwin, vol. 11