To B. D. Walsh 27 March [1865]1
Down. | Bromley. | Kent. S.E.
Mar 27.
My dear Sir
I have been much interested by your letter.2 I received your former paper on Phytophagic unity, most of which was new to me.3 I have since received your paper on willow-galls: this has been very opportune as I wanted to learn a little about galls.4 There was much in this paper which has interested me extremely, on gradations &c and on your “unity of correlation”.5 This latter subject is nearly new to me, though I collected many years ago some such cases with birds;6 but what struck me most was when a bird-genus inhabits two continents the two sections sometimes display a somewhat different type of colouring. I shd like to hear whether this does not occur with widely ranging insect-genera?
You may like to hear that Wichura has lately published a book which has quite convinced me that in Europe there is a multitude of spontaneous hybrid willows. Wd it not be very interesting to know how the gall-makers behaved with respect to these hybrids?7 Do you think it likely that the ancestor of Cecidomyia acquired its poison like Gnats. (which suck men) for no especial purpose; at least not for gall-making.?8 Such notions make me wish that some one wd try the experiments suggested in my former letter.9 Is it not probable that Guest-flies were aboriginally gall-makers, & bear the same relation to them which Apathus probably does to Bombus?10 With respect to Dimorphism you may like to hear that Dr Hooker tells me that a dioicous parasitic plant allied to Rafflesia has its 2 sexes parasitic on 2 distinct species of the same genus of plants;11 so look out for some such case in the 2 forms of Cynips.12 I have posted to you copies of my papers on Dimorphism.13 Leersia does behave in a state of nature in the provoking manner described by me.14 With respect to Wagner’s curious discovery my opinion is worth nothing:15 no doubt it is a great anomaly, but it does not appear to me nearly so incredible as to you: remember how allied forms in the Hydrozoa differ in their so-called alternate generations: I follow those naturalists who look at all such cases as forms of Gemmation;16 & a multitude of organisms have this power or traces of this power, at all ages from the germ to maturity. With respect to Agassiz’s views there were many, & there are still not a few, who believe that the same species is created on many spots.17 I wrote to Bates & he will send you his mimetic paper, & I dare say others: he is a first rate man.18
Your case of the wingless insects near the Rocky mountains is extremely curious:19 I am sure I have heard of some such case in the old world, I think on the Caucasus. Wd not my argument about wingless insular insects perhaps apply to truly Alpine insects; for wd it not be destruction to them to be blown from their proper home?20 I shd like to write on many points at greater length to you, but I have no strength to spare—
With every good wish believe me yours very sincerely | Charles Darwin
If you publish on wingless insects, kindly inform me or send, if you can, a copy.—
Footnotes
Bibliography
Agassiz, Louis. 1857–62. Contributions to the natural history of the United States of America. 4 vols. Boston, Mass.: Little, Brown & Company. London: Trübner.
Bates, Henry Walter. 1861. Contributions to an insect fauna of the Amazon valley. Lepidoptera: Heliconidæ. [Read 21 November 1861.] Transactions of the Linnean Society of London 23 (1860–2): 495–566.
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.
‘Dimorphic condition in Primula’: On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations. By Charles Darwin. [Read 21 November 1861.] Journal of the Proceedings of the Linnean Society (Botany) 6 (1862): 77–96. [Collected papers 2: 45–63.]
Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.
Notebooks: Charles Darwin’s notebooks, 1836–1844. Geology, transmutation of species, metaphysical enquiries. Transcribed and edited by Paul H. Barrett et al. Cambridge: Cambridge University Press for the British Museum (Natural History). 1987.
OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.
Origin 4th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 4th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1866.
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.
Ornithological notes: Darwin’s ornithological notes. Edited by Nora Barlow. Bulletin of the British Museum (Natural History). Historical Series 2 (1959–63): 203–78.
‘Three forms of Lythrum salicaria’: On the sexual relations of the three forms of Lythrum salicaria. By Charles Darwin. [Read 16 June 1864.] Journal of the Linnean Society (Botany) 8 (1865): 169–96. [Collected papers 2: 106–31.]
‘Two forms in species of Linum’: On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. By Charles Darwin. [Read 5 February 1863.] Journal of the Proceedings of the Linnean Society (Botany) 7 (1864): 69–83. [Collected papers 2: 93–105.]
Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.
Walsh, Benjamin Dann. 1864–5. On phytophagic varieties and phytophagic species. Proceedings of the Entomological Society of Philadelphia 3: 403–30, 5: 194–216.
Wichura, Max Ernst. 1865. Die Bastardbefruchtung im Pflanzenreich erläutert an den Bastarden der Weiden. Breslau: E. Morgenstern.
Summary
Comments on BDW’s papers ["On certain entomological speculations of the New England school of naturalists", Proc. Entomol. Soc. Philadelphia 3 (1864): 207–49; "On insects inhabiting the galls of certain species of willow", ibid. 3 (1864): 543–644]; much is new to CD.
Asks about wide-ranging insect genera,
Rocky Mt. wingless insects,
willow hybrids,
galls,
and other subjects.
Letter details
- Letter no.
- DCP-LETT-4797
- From
- Charles Robert Darwin
- To
- Benjamin Dann Walsh
- Sent from
- Down
- Source of text
- Field Musuem of Natural History, Chicago (Walsh 3)
- Physical description
- LS(A) 5pp †
Please cite as
Darwin Correspondence Project, “Letter no. 4797,” accessed on 31 October 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-4797.xml
Also published in The Correspondence of Charles Darwin, vol. 13