# To Daniel Oliver   7 November [1860]1

15 Marine Parade | Eastbourne

Nov 7th

(We leave, I hope & think on Saturday.)2

My dear Mr Oliver

I am heartily glad to hear that the Professorship is properly decided.—3

I have been glad to see the slide, but I am sorry to say the glass arrived cracked. I do not think that the structure is so plain as when I made fresh slices. I shall be some time curious to know what you see so remarkable in the sensitive Hairs.—   I hope some day you will study the Dionæa & publish on it. I shall make only a few remarks in comparison with Drosera.4 I can see nothing in Sensitive Hairs more than I saw before, viz elongated cells arranged spirally with a bifid point, with no spiral vessel or stomata.— There is a short footstalk making change of structure in cells & that is all I can see! I conjecture that the sensitive Hairs are homologous with the tortoise-shells or buttons, in a much elongated condition.—   I cannot help fancying that by holding footstalk of living leaf & retarding the movement by your thumb with good lens, you could see whether the sensitive Hair became mottled in colour by touching it with needle. (I can tell with Lens whether Hairs of Drosera are mottled.) It ought to do so!!—   I shall be intensely curious to hear about C. of Ammonia & Dionæa.—5

I have tried several salts on the Hairs & Roots of Drosera & on other plants.6 But I know well I have not tried enough; nor intend to do so for the work is quite out of my line; & though I have enjoyed it very much, I have been exceedingly foolish to attempt it. I still think the action of the Carbonate & some other salts of Ammonia remarkable. & worth any one’s following out.—   I shall briefly give the facts in my paper.— I put all the roots of a little plant of Euphorbia in water with $\frac{1}{8}$ th of grain of C. of Ammonia, & it was curious how it wholly altered the appearance of every cell in all the roots.—7 The action is so rapid, that you cannot put the root under the microscope, before clouds of granules have shot some way up the roots.—

Now I am going to beg a little favour of you—   Does not Mr Fitch work at Kew?8 And will he draw for anyone for payment? If he will be so good as to make 2 or 3 drawings for me, I shd be very much obliged & I could repay by P. order.

First, a leaf of Drosera with all the Hairs fully expanded. It is for woodcut for any reader who is not a Botanist. It ought to be 3 or 4 times natural size. Mr F. could judge this. It ought to be done neatly.— The extreme marginal Hairs are long-headed; whether on this scale the difference could be represented, I know not.—

Secondly would you put little fly on exact middle of leaf, & after Hairs are well clasped get a drawing made on same scale.

Thirdly, perhaps, sketch of leaf of Dionæa, just to interest Reders.9 I shall have copied from Trécul the minute structure of Hairs.—10

My dear Sir | Yours very sincerely | C. Darwin

## Footnotes

The year is given by the reference to Oliver’s appointment as professor at University College London (see n. 3, below).
The Darwins left Eastbourne for Down on Saturday, 10 November 1860 (‘Journal’; Appendix II).
Oliver had applied for the professorship of botany at University College London previously held by John Lindley. CD wrote a letter of recommendation for him (see letter to William Sharpey, 28 October [1860]). Oliver’s appointment was announced in the Athenæum, 10 November 1860, p. 633.
CD refers to the paper on Drosera he was preparing. He read it at a meeting of the Philosophical Club of the Royal Society in February 1861 (Bonney 1919, p. 154). He compared the structure of Dionaea and Drosera in Insectivorous plants, pp. 286–320.
There is a sheet summarising the results of CD’s experiments on the effects of various salts on plant cells in DAR 60.2: 89.
See letter to Daniel Oliver, 3 November [1860]. The results of CD’s experiments are described in Insectivorous plants, pp. 63–5.
Walter Hood Fitch was employed as botanical draughtsman at the Royal Botanic Gardens, Kew, where Oliver also worked.
In fact, Fitch did not supply the drawings for Insectivorous plants. All of the figures of Dionaea and Drosera were drawn by George Howard Darwin, and those of Aldrovanda and Utricularia by Francis Darwin (Insectivorous plants, p. 3 n.). Fitch may have illustrated the manuscript CD was preparing on Drosera (see n. 4, above); he prepared the drawings for CD’s 1862 paper on Primula (see Correspondence vol. 9, letter to Daniel Oliver, 23 March [1861]).
Although CD discussed Trécul 1855 in Insectivorous plants, he did not use any illustrations from this work.

## Summary

Congratulations on Professorship.

Homologies between Drosera and Dionaea. Carbonate of ammonia on roots. Wants W. H. Fitch to make drawings of Dionaea. Will copy minute structure of hairs from Trécul [see 2965].

## Letter details

Letter no.
DCP-LETT-2977
From
Charles Robert Darwin
To
Daniel Oliver
Sent from
Eastbourne
Source of text
Down House (MS 10: 25)
Physical description
4pp

## Please cite as

Darwin Correspondence Project, “Letter no. 2977,” accessed on 22 October 2017, http://www.darwinproject.ac.uk/DCP-LETT-2977

Also published in The Correspondence of Charles Darwin, vol. 8

letter