To G. H. K. Thwaites 15 June [1862]1
Down. | Bromley. | Kent. S.E.
June 15th
My dear Mr Thwaites
If you see Linn. Journal, I hope that you will read my paper on the fertilisation of Primula.2 Why I hope that you will do this, is because I have been told that Dr. Weddell states that Cinchona presents the same case of some individual trees with long pistils & some with short.3 Now if this be the case, it is almost certain that in order to get good seed & good seedlings there must be reciprocal fertilisation between the two forms. It is quite likely, but by no means certain, that Ceylon insects may do this work effectually; but the subject, I am sure, is worth your attention.
If there be any difficulty in getting seed in Ceylon, or in raising strong plants from Ceylon seed, do I beg you, try artificial fertilisation on a few dozen flowers, making the cross between the two forms.— There is no need of castration The growth of Cinchona is so important for mankind, that I am sure you will excuse my making this suggestion.4 It is a subject I am still working at.5 This form of dimorphism seems common with the Rubiaceæ;6 & if you have observed any analogous facts I shd. be grateful for information.—
I sincerely hope that you are well & in all ways prosperous.—
Pray believe me | Yours very sincerely | Ch. Darwin
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
‘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.]
EB: The Encyclopædia Britannica. A dictionary of arts, sciences, literature and general information. 11th edition. 29 vols. Cambridge: Cambridge University Press. 1910–11.
General index to the Journal of the Linnean Society: General index to the first twenty volumes of the Journal (Botany), and the botanical portion of the Proceedings, November 1838 to June 1886, of the Linnean Society. London: Linnean Society of London. 1888.
Weddell, Hugh Algernon. 1849. Histoire naturelle des quinquinas ou monographie du genre Cinchonasuivie d’une description du genre Cascarillaet de quelques autres plantes de la même tribu. Paris: V. Masson.
Summary
Refers to his Primula paper [Collected papers 2: 45–63]. Asks GHKT to investigate a similar case in Cinchona.
Letter details
- Letter no.
- DCP-LETT-3606
- From
- Charles Robert Darwin
- To
- George Henry Kendrick Thwaites
- Sent from
- Down
- Source of text
- American Philosophical Society (Mss.B.D25.278)
- Physical description
- ALS 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 3606,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-3606.xml
Also published in The Correspondence of Charles Darwin, vol. 10