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Darwin Correspondence Project

From George Dickie   30 May 1862

Aberdeen

May 30, 1862

Dear Sir,

In accordance with your wish I procured a supply of L. cordata & made some observations on it—1 About the time of full expansion & when the pollen is matured the small hairs on the lower surface of rostellum are directed perpendicularly downwards & their points touch the central line of the labellum. I carefully—under a lense—pushed a bristle along central line of labellum towards the rostellum; it or any other small body cannot penetrate the space between rostellum & labellum without coming in contact with hairs & front margin of the former; when such contact occurs there is a sudden explosion & the whole pollen mass instantly adheres to the touching body, the rostellum at the same time spreading out & covering the stigmatic surface. After a time the rostellum becomes retracted & the stigma exposed; so that the pollen cannot possibly touch the stigma of its own flower, but when applied to another—whose pollinia are removed—fragments adhere. Small Diptera and Hymenoptera have been seen on the flowers but as yet no pollinia on them. I send you bristles with adhering pollinia, I fear however they may become detached during their long journey by post.

I have read your work with much satisfaction,2 & while subscribing to your remarks—page 28—respecting adaptations,3 I frankly confess that I cannot comprehend how they can be explained by “natural selection” or what relation they have to that view.

Truly yours | G Dickie

CD annotations

Top of letter: ‘Listerared crayon; ‘I noticed that R. was very much turned down in Mr Jamiesons specimen.—’4 ink

Footnotes

George Dickie was professor of botany at the University of Aberdeen. He had provided CD with specimens of the orchid Listera cordata in 1861 (see Correspondence vol. 9, letter to George Dickie, [5 July 1861], and letter to George Gordon, 6 July [1861]). Dickie’s assistance is acknowledged in Orchids, p. 152, where CD reported that he had requested the specimens ‘rather too late in the season’. CD incorporated the observations given here in the German edition of Orchids (Bronn trans. 1862, pp. 94–5n; see the second enclosure to the letter to H. G. Bronn, 30 June [1862]).
Dickie’s name appears on the presentation list CD drew up for Orchids (see Correspondence vol. 10, Appendix IV).
In Orchids, p. 28, CD concluded a minute account of the perfect adaptation of form to function in Orchis pyramidalis, saying: in no other plant, or indeed in hardly any animal, can adaptations of one part to another, and of the whole to other organised beings widely remote in the scale of nature, be named more perfect than those presented by this Orchis
In 1861, CD had asked the agriculturalist and geologist Thomas Francis Jamieson, who, like Dickie, resided in Aberdeenshire, to procure for him specimens of the orchid Listera cordata (see Correspondence vol. 9, letter from T. F. Jamieson, 13 June 1861). There is a note, dated 31 May 1862, in DAR 70: 77, recording observations on a specimen of this orchid supplied by Jamieson.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 26 vols to date. Cambridge: Cambridge University Press. 1985–.

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.

Summary

Reports observations on Listera cordata in accordance with CD’s wishes.

Agrees with what CD says about adaptations [in Orchids, p. 28–31], but cannot comprehend how they can be explained by natural selection.

Letter details

Letter no.
DCP-LETT-3578
From
George Dickie
To
Charles Robert Darwin
Sent from
Aberdeen
Source of text
DAR 162.2: 178
Physical description
4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 3578,” accessed on 15 December 2019, https://www.darwinproject.ac.uk/letter/DCP-LETT-3578.xml

Also published in The Correspondence of Charles Darwin, vol. 10

letter