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Darwin Correspondence Project

To J. D. Hooker   7 April [1855]


Ap. 7th.

My dear Hooker

I wrote this morning to thank for the Rhododendrums.—

I have begun my seed-salting experiments,1 & I shd. be extremely much obliged if you would tell me what kinds you would expect to be most easily killed by sea-water besides the Cruciferæ, which I had thought wd. be so, & which you confirmed; I had meant to have asked, but quite forgot, when I last saw you.—2

If you can mention any that are easily procured, as Agricultural or Garden or flower seeds,—please enumerate Just a few.— Secondly will you tell me, at a guess, how long an immersion in sea-water you shd. imagine wd. kill the more susceptible seeds? Should you expect a week’s fair immersion wd. destroy any of them?

I have looked in Lindleys Vegetable K. & understand what is meant.3

Will you be so kind as to send me a brief note in answer, as I may thus be sooner put out of my pain, & end my experiments, which I daresay you think as foolish, as my splendid idea, that the Coal-plants lived in salt-water like mangroves which made you so savage4

Adios | C. Darwin

My notions sometimes bring good; Dr. Davy5 has been experimenting at my request, (in order to see how fishes’ ova might get transported) on the retention of vitality; & he found that salmon’s ova, exposed for 3 whole days to open air, & even some sun-shine, & they produced fine young fish. Dr. D. has sent a paper to Royal Soc. on the subject.— N.B. Remember to ask about my distinct case of “a lady in N. America” who saw fishes’ spawn adhering to a Ditiscus.6


CD’s notes on his seed-salting experiments are in DAR 27.1 (ser.7): 1–23. Experiments were begun on 30 March 1855 (f. 7v.). Some notes dated 15 March 1855 and headed ‘Casual notes on my collection of seeds.’ are in DAR 46.2: 3–4.
CD had visited Hooker at Kew during his four-day visit to London, 20 to 24 March 1855 (letter to C. J. F. Bunbury, [20 March 1855], n. 1, and letter to Miles Joseph Berkeley, 7 April [1855]).
This sentence follows a deleted passage in which CD said that he did not know which seeds were albuminous (see Manuscript alterations and comments). John Lindley’s Vegetable kingdom divided dicotyledonous plants (exogens) into those orders whose embryos are furnished with abundant albumen and those with none or only a moderate amount (Lindley 1846, p. 246). Lindley believed the distinction to be as fundamental as that between oviparous and viviparous animals. To CD, the embryos with abundant albumen would be those most likely to last the longest under adverse conditions.
The origin of coal was the subject of heated correspondence with Hooker in May 1847. See Correspondence vol. 4, letters to J. D. Hooker, [1 May 1847] and [6 May 1847]. CD’s seed-salting experiments were in part prompted by a statement in J. D. Hooker 1853–5, 1: xx: ‘I cannot think that those who, arguing for unlimited powers of migration in plants, think existing means ample for ubiquitous dispersion, sufficiently appreciate the difficulties in the way of the necessary transport.’ Hooker recorded how he was then led to speculate on the possibility of a former landmass connecting, at various times and places, New Zealand with Chile, Australia, the Antarctic, and the several neighbouring Pacific islands. CD, on the other hand, entertained the possibility that seeds and young plants and the ova of fish could be transported by a number of means, including birds and other animals, by the air, by ice, and by floating in sea-water.
See letters to John Davy, 25 March [1855] and 26 March [1855].
CD had received an account of a water-beetle carrying the ova of fish on its legs through Richard Chandler Alexander, a botanist and acquaintance of the Hooker family. See letter from M. H. Morris to R. C. Alexander, 17 June 1855.


CD has begun seed-salting experiments. Wants JDH to write which seeds he expects to be easily killed [in salt water].

CD’s idea that coal-plants lived in salt water like mangroves made JDH savage.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 114: 127
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1661,” accessed on 23 June 2017,

Also published in The Correspondence of Charles Darwin, vol. 5