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Darwin Correspondence Project

To J. D. Hooker   6 September [1861]


Sept 6th

My dear Hooker

One line to say that the magnificent Book arrived quite safe.1 I fear it will take me some little time to go through it.— Many thanks for names of Orchids. I am heartily glad to hear that Mrs Hooker is better & that you will sometime come to Down.—

If Oliver is at Kew remember me very kindly to him. Tell him I have got the Dionæas through his suggestion from Chichester & shall begin to observe tomorrow.2 By the way if Oliver is at Kew, will you ask him to be so kind as to tell me anything he can about origin or habitat of Primula ciliata & P. ciliata var. purpurata   Is it a wild var? They differ oddly in one important respect & I am very curious to know what this var. is.3

I think that you will think that I have made out the meaning of Dimorphism in Primula, satisfactorily & a very odd case it is & has caused me much labour in artificial crossing.4

Ever yours | my dear Hooker | C. Darwin

Orchids are inexhaustible in contrivances: Dendrobium chrysanthemum was given me yesterday & it has such a splendid contrivance, so that if an insect fail in removing the pollinia by the sticky matter, the pollinia are pitched right over the rostellum & always alight on the stigma, so nicely adapted is the force of the spring.5


Daniel Oliver, assistant in the herbarium of the Royal Botanic Gardens, Kew, had been helping CD with his study of the sensitivity of the leaves of Dionaea and other insectivorous plants to nitrogenous substances. CD’s observations and experiments on Dionaea are described in Insectivorous plants, pp. 286–320.
CD read his paper ‘On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations’ to the Linnean Society on 21 November 1861. See Collected papers 2: 45–63.
The pollination mechanism of Dendrobium chrysanthum is described in Orchids, pp. 172–8.


Bauer, Franz Andreas. 1830–8. Illustrations of orchidaceous plants … with notes and prefatory remarks by John Lindley. London.

Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.

Insectivorous plants. By Charles Darwin. London: John Murray. 1875.

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.


After much crossing, has worked out meaning of dimorphism in Primula.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 115: 112
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 3248,” accessed on 18 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 9