To Daniel Oliver 16 November [1860]1
Down Bromley Kent
Nov 16th
My dear Mr Oliver
In writing out my paper yesterday I was so astounded at my results that I have got fairly frightened, & have determined to finish my paper, but to publish nothing until next summer2 I shall have retested my results & tried some of them in another way: so that there is no hurry about the Drawings.3 If there are good specimens, I shd be glad for Mr Fitch to complete them; otherwise will you ask him to wait till next spring or summer.—
Most heartily do I thank you for your most kind & valuable assistance.— If I could get one or two plants of Dionæa I would experimentise on them; but I shall not of course attempt the anatomy; & if you thought you would undertake the subject, I would not interfere in any way, except by bare allusions to what I have seen; but it is so important to me about the mottling or segregation of colour, that I shd. extremely much wish to ascertain that point, if in the Spring, by the aid of Mr Croker I could purchase (at almost any price) one or two or three of the young plants which he saw.—4
I have been corresponding with some of the chemical physiologists & as far as I can find out the curious action of the C. of Ammonia on the roots of plants has not been observed.—
With cordial thanks for all your kindness | My dear Mr Oliver | Yours very sincerely | C. Darwin
P.S. | Can you tell me name of Plant, which grew out of doors in my Fathers garden, 2 to 4 ft high—considerably branched, died down (I think) in winter, bore many minute almost white or very pale pink flowers, & which flowers caught a multitude of flies by their probosces.—5 I shd. like to get a plant to try to make out final cause of the catching.—
P.S. 2d. | Perhaps you would like to hear following extraordinary fact.— I have placed over & over again minute atoms of paper, stick, cinders meat flies &c on glands of single hairs of Drosera & they always became inflected; so I thought I would test how minute an atom would cause movement: I measured with micrometer several bits of woman’s Hair (& thread) which caused movement & found that under th of inch amply sufficed. Of same hair I sent 6 inches to be weighed in London by best balance, & it weighed under of grain, which shows that 1/30,000 of a grain suffices!!6
Prolonged pressure alone causes movement.
Footnotes
Bibliography
Bonney, T. G. 1919. Annals of the Philosophical Club of the Royal Society written from its minute books. London: Macmillan.
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Insectivorous plants. By Charles Darwin. London: John Murray. 1875.
Summary
One thirty-thousandth of a grain of human hair inflects a single Drosera hair. Astonished by his results so he is not publishing until next summer. [Not published until 1875, Insectivorous plants. See ch. 2 for observations on inflection.]
Wants to study effects of acids on live Dionaea. Oliver should do their anatomy. Corresponding with chemical physiologists about carbonate of ammonia on roots.
Letter details
- Letter no.
- DCP-LETT-2985
- From
- Charles Robert Darwin
- To
- Daniel Oliver
- Sent from
- Down
- Source of text
- DAR 261.10: 26 (EH 88206010)
- Physical description
- ALS 6pp
Please cite as
Darwin Correspondence Project, “Letter no. 2985,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-2985.xml
Also published in The Correspondence of Charles Darwin, vol. 8