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Darwin Correspondence Project

To J. D. Hooker   8 September [1856]1

Down Bromley Kent

Sept. 8th.

My dear Hooker

I got your letter of the 1st. this morning;2 & a real good man you have been to write. Of all the things I ever heard, Mrs. Hooker’s pedestrian feats beats them. My Brother is quite right in his comparison of “as strong as a woman”,—as a type of strength.— Your letter, after what you have seen in Himalaya &c, gives me a wonderful idea of the beauty of the Alps. How I wish I was one half or one quarter as strong as Mrs. Hooker: but that is a vain hope. You must have had some very interesting work with glaciers &c.3 When will the glacier structure & motion ever be settled! When reading Tyndall’s paper it seemed to me that movement in the particles must come into play in his own doctrine of pressure;4 for he expressly states that if there be pressure on all side, there is no lamination: I suppose I cannot have understood him, for I shd. have inferred from this that there must have been movement parallel to planes of pressure. Sorby read paper to Brit. Assoc. & he comes to conclusion that Gneiss &c may be metamorphosed cleavage or strata; & I think he admits much chemical segregation along the planes of division.5 I quite subscribe to this view, & shd. have been sorry to have been so utterly wrong, as I shd. have been, if foliation was identical with stratification.6

I have been no where & seen no one & really have no news of any kind to tell you.— I have been working away as usual (floating plants in salt-water inter alia & confound them, they all sink pretty soon, but at very different rates) working hard at Pigeons &c &c By the way I have been astonished at differences in skeletons of domestic Rabbits:7 I showed some of the points to Waterhouse & asked him whether he could pretend that they were not as great as between species, & he answered “they are a great deal more”.—8 How very odd it is that no zoologist shd. ever have thought it worth while to look to the real structure of varieties.—

I most earnestly hope that at Vienna you will make particular enquiries about the pure Laburnum, which one year bore the hybrid flowers & on one sprig the C. purpureus.—9 Dr. Reissik(?) is name of man I think.— Bentham10 will not believe that it was a pure Laburnum, & it does seem quite incredible, notwithstanding the clear statements in the Flora.11 Please enquire particularly whether the hybrid or purple or pure bears seeds: I have just got the seeds of a yellow branch from the sterile hybrid to sow & see what will come up.— Really this case ought to be investigated,12 & if you, the King of Sceptics believe, all others may.—

My poor wife keeps very uncomfortable, but rather better than she was.13

With our kindest regards to Mrs Hooker. | Believe me | My dear Hooker | Ever yours | C. Darwin


Dated by the reference to Hooker’s holiday in Switzerland (see n. 3, below).
The letter has not been found.
The Hookers were on a walking holiday in Switzerland, where they by chance met Thomas Henry Huxley and John Tyndall who had gone to the Alps to investigate James David Forbes’s theory of glacial movement (L. Huxley ed. 1900, 1: 145, and Eve and Creasey 1945, p. 64).
Henry Clifton Sorby proposed that cleavage took place when metamorphosed stratified rock that had been foliated was subjected to contortion and pressure. Thus slaty cleavage could not, as CD had thought, be partially developed foliation. The problem of the origin of cleavage and foliation had been the subject of much of CD’s correspondence with Daniel Sharpe and Charles Lyell in 1854 and 1855 (see Correspondence vol. 5).
Rabbits and their skeletal variations are discussed in chapter 4 of Variation.
George Robert Waterhouse had classified wild rabbits in Waterhouse 1846–8.
CD refers to the brief account of Siegfried Reissek’s anomalous laburnum given in Hornschuch 1848, pp. 25–7. See letter to J. D. Hooker, 22 June [1856], n. 2.
Hooker wrote the following note at the end of the letter: ‘Only that one time produced red &c flowers impossible that it was a graft The same thing observed in Hungary & Bohemia in many gardens also at Schoenberg’.
Emma Darwin was in her sixth month of pregnancy. Her last child, Charles Waring Darwin, was born on 6 December 1856.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Hornschuch, Christian Friedrich. 1848. Ueber Ausartung der Pflanzen. Flora, oder allgemeine botanische Zeitung n.s. 6: 17-28, 33–44, 50–64, 66–86. [Vols. 5,6]

Sorby, Henry Clifton. 1856. On the microscopical structure of mica-schist. Report of the 26th meeting of the British Association for the Advancement of Science held at Cheltenham, Transactions of the sections, p. 78.

Tyndall, John. 1856. Comparative view of the cleavage of crystals and slate rocks. Notices of the Proceedings at the meetings of the members of the Royal Institution of Great Britain 2 (1854–8): 295–308.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Waterhouse, George Robert. 1846–8. A natural history of the Mammalia. 2 vols. London: H. Baillière.


Whether or not there should be movement of particles according to Tyndall’s theory of glacial action ["Observations on glaciers", Not. Proc. R. Inst. G. B. 2: 54–8, 441–3].

CD subscribes to H. C. Sorby’s view of gneiss [Edinburgh New Philos. J. 55 (1853): 137–50].



Significant differences in skeletons of domesticated rabbits.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 114: 176
Physical description
ALS 6pp ††

Please cite as

Darwin Correspondence Project, “Letter no. 1950,” accessed on 15 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 6