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Darwin Correspondence Project

DCP-LETT-2939

To Daniel Oliver   5 October [1860]1

15 Marine Parade | Eastbourne

Oct. 5th

My dear Sir

I thank you for two notes.2 It was a capital thought your sending me the gum itself (so ingeniously bottled or quilled); I tried it on 3 leaves, & it produced no effect; & I tried thicker gum on 5 other leaves with no effect, & I subsequently proved that these leaves were good ones.3 If a leaf is feeble & does not secrete copiously, the gum dries & draws together all the hairs which it has touched; & this, I imagine, must have been cause of the apparent inflection in your case. At last I have come to a puzzler, for I find Carb. of Soda causes inflection;4 but I have sent to London for pure C. of soda, & as that sold by Druggists is not pure. But I strongly suspect I have come across a poser. I am, however, trying my experiments in another fashion, which may throw light on subject.—   I find the glands at end of Hairs are absorbers as well as secreters. The change which takes place in the Hairs after inflection is very curious. The currents & movements in the cells strike me in my ignorance as marvellous.—

You are very kind in your second note to say that I must not apologise for all the trouble which I have caused; but pray thank Mr Croker for enquiring about the Dionæa.—5 Also please give my best thanks to Sir William for his wish to oblige me;6 I shall be intensely curious to examine the leaves; if I cannot get a plant. If the Dionæa commonly catches only small fry, I shd. not be surprised at a fat fly being too much for its digestion; at least I have found bits of raw meat often, indeed I think generally, kill the leaf of the Drosera. I shd like to hear whether Croker is pretty certain of this fact.—

I am very glad to hear that you are experimentising on the leaves in water. I have long thought that naturalists make far too few experiments.—

My dear Sir | Yours very sincerely | C. Darwin

Do you possess a copy of my “Origin of Species”; if you do not, I should much like to have the pleasure of sending you one.—7

Footnotes

1
Dated by the relationship to the letters from Daniel Oliver, 19 September 1860 and 25 September 1860.
2
The notes from Oliver have not been found.
3
See letter from Daniel Oliver, 25 September 1860, and letter to Daniel Oliver, 27 [September 1860]. CD’s notes on his experiments are in DAR 60.1: 110.
4
CD’s first experiments on Drosera had led him to expect to find that only nitrogenous substances would stimulate inflection of the leaf-hairs.
5
Charles William Crocker was foreman of the propagating department at the Royal Botanic Gardens, Kew. See letter to Daniel Oliver, 15 [September 1860].
6
William Jackson Hooker was the director of the Royal Botanic Gardens, Kew. See letter to Daniel Oliver, [29 September 1860].
7
According to a note by Francis Wall Oliver (Daniel Oliver’s son) added to the typed copy he made of this letter, CD subsequently sent Oliver a copy of the first edition of Origin with a ‘letter of dedication’. However, this would appear to be in error: see second letter to Daniel Oliver, 12 [October 1860], and Appendix III. The letter of dedication recalled by F. W. Oliver may relate to the copy of Journal of researches that CD sent Oliver later in October.

Summary

A poser: carbonate of soda produces inflection rather than contraction in Drosera. Possible solution: glands at end of hairs absorb as well as secrete. Fascinated by currents in cells after inflection.

Letter details

Letter no.
DCP-LETT-2939
From
Darwin, C. R.
To
Oliver, Daniel
Sent from
Eastbourne
Source of text
Down House (MS 10: 14)
Physical description
5pp

Please cite as

Darwin Correspondence Project, “Letter no. 2939,” accessed on 25 August 2016, http://www.darwinproject.ac.uk/DCP-LETT-2939

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