Ɛpsilon

To J. J. Weir   19 October 1871

Down, Beckenham, Kent.

Oct. 19, 1871.

My dear Sir

I am obliged for your interesting fact.1 I have heard of analogous cases, especially of a striking one in Ceylon.2 Like you I have often wondered at the different food of the old and young, as with graminivorous birds feeding their young with insects. I imagine we must look back to primeval times when the young and old lived on the same food. Sir J. Lubbock in his forthcoming Vol. in the Ray Soc. will give some valuable remarks on the means of transition between the mandibulata and haustellata.3 I think the Gonepteryx must feed on some plants besides the Rhamnus, for I believe this bush in many districts is absent, whilst the butterfly is common.4

With many thanks for your note believe me | Yours very sincerely | Ch. Darwin.

Copy

1
Weir’s letter to CD has not been found.
2
Ceylon is now Sri Lanka.
3
CD had read the proof-sheets of Lubbock 1873 in August 1871 (see letter to John Lubbock, 12 August [1871]). In Lubbock 1873, pp. 50–2, Lubbock discussed the development of mandibulate insects (those that fed by chewing) and suctorial or haustellate insects (those that fed by puncturing and sucking), including insects that fed by different methods at different life-stages.
4
Weir’s letter may have concerned his observations of caterpillars of Gonepteryx rhamni (the common brimstone butterfly) on Rhamnus alaternus (Italian buckthorn), a species not native to the British Isles (see note in Entomologist 8 (1875): 160–1).

Please cite as “DCP-LETT-8018,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-8018