Ɛpsilon

To W. T. Thiselton-Dyer   5 September [1877]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Sept 5th

My dear Dyer

One word to thank you. I declare had it not been for your kindness, we shd. have broken down.— As it is we have made out clearly that with some plants (chiefly succulent) the bloom checks evaporation.— with some certainly prevents attacks of insects— with some sea-shore plants prevents injury from salt-water—& I believe with a few prevents injury from pure water resting on leaves— This latter is as yet the most doubtful & the most interesting point in relation to the movement of plants.—2

I daresay what you say about Scitamineæ & Sachs is right.—3 I already know that Thalia dealbata (which we owe to you) sleeps magnificently; & we are now tracing the movements during the 24 hours.—4

Hearty thanks | Ch. Darwin

1
The year is established by the relationship between this letter and the letter to W. T. Thiselton-Dyer, 31 August [1877].
2
Thiselton-Dyer had provided CD with specimens relating to and information on bloom (see, for example, letter to W. T. Thiselton-Dyer, 22 July [1877]). For CD’s interest in bloom, see the letter to Fritz Müller, 14 May 1877 and n. 2. CD and Francis studied bloom in tandem with work on movement in plants; their experiment notes from 1877 and 1878 are in DAR 66 and DAR 68: 1–22.
3
See letter to W. T. Thiselton-Dyer, 31 August [1877] and n. 10. No reply from Thiselton-Dyer on Julius von Sachs’s description of sleeping and waking in the Scitamineae has been found.
4
CD published his observations on the diurnal movement of the leaves of Thalia dealbata (powdery alligator-flag) in Movement in plants, p. 389. Specimens of T. dealbata had been sent from Kew on 3 July 1877 (see letter to W. T. Thiselton-Dyer, 9 July [1877] and n. 2), and there is a brief note, dated 8 September 1877, on the effects of shaking the plant and beating the growing tip in DAR 67: 7r. See also letter to Fritz Müller, 14 May 1877 and n. 2.

Manuscript Alterations and Comments

1.2 chiefly] interl after interl & del ‘chi’

Please cite as “DCP-LETT-11128,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11128