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Darwin Correspondence Project

To A. S. Wilson   9 August [1878]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R. [Leith Hill Place, Surrey.]

Aug. 9th

Dear Sir

Your observations seem to me very interesting.— I remember many years ago being perplexed by Erythræa, but I do not think that I compared the pollen.—2 I wd. suggest to you to compare many specimens next year, & if you have any opportunity transplant the plants into a garden & experimentise on them & publish the results.—

Your remarks on the Wasps alighting on summit of the stems of the Scrophularia are very curious & good; but, as it seems to me, many more observations are requisite before you could safely make any generalisation on relation of colours of flowers & visits of wasps. I remember, however, speculating on the subject, but wasps visiting Tritoma upset my notions.3

I am writing away from home & am not well,4 so excuse brevity, & with hearty wishes for the success & continuation of your observations, I remain Dear Sir | Yours faithfully | Ch. Darwin


The year is established by the relationship between this letter and the letter from A. S. Wilson, 6 August 1878.
See letter from A. S. Wilson, 6 August 1878 and nn. 1 and 3. Erythraea is a synonym of Centaurium (the genus of centaury). For CD’s earlier questions about the forms of Erythraea centaurium, see Correspondence vol. 10, letter to W. E. Darwin, [24 July 1862].
In his letter of 6 August 1878, Wilson noted that he had observed wasps visiting the highest flowers first on stems of Scrophularia nodosa (woodland figwort). He pointed out that bees generally visited the lowest flowers of a plant first and speculated that this difference might explain protogyny (female sexual parts maturing before male) in flowers that were adapted for cross-fertilisation by wasps. The former plant genus name Tritoma is a synonym of Kniphofia (red-hot poker or torch lily); individual flowers of the cone-shaped inflorescences bloom in sequence from the base up.
The Darwins visited family in Surrey and Staffordshire between 7 and 22 August 1878 (CD’s ‘Journal’ (Appendix II)). This letter was written from Leith Hill Place, the home of CD’s sister, Caroline Sarah Wedgwood, and her family.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.


Responds to ASW’s information about Erythraea

and about wasps on Scrophularia.

Letter details

Letter no.
Charles Robert Darwin
Alexander Stephen Wilson
Sent from
Leith Hill Place Down letterhead
Source of text
Cambridge University Library (MS Add. 7339: 57)
Physical description
ALS 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 11646,” accessed on 23 July 2024,