skip to content

Darwin Correspondence Project

To J. D. Hooker   24 November 1873

Down, | Beckenham, Kent.

Nov. 24 1873.

My dear Hooker

I have been greatly interested by Mimosa Albida, on which I have been working hard. Whilst yr memory is pretty fresh, I want to ask a question: When this plant was most sensitive & you irritated it, did the opposite leaflets shut up quite close, as occurs during sleep, when even a lancet cd not be inserted between the leaflets? I can never cause the leaflets to come into contact, & some reasons make me doubt whether they ever do so, except during sleep; & this makes me wish much to hear from you.1 I grieve to say that tho’ plant looks more unhealthy even than it was at Kew, I have nursed it like the tenderest infant; but I was forced to cut off one leaf to try the bloom, & one was broken by the manner of packing. I have never syringed (with tepid water) more than 1 leaf per day; but if it dies, I shall feel like a murderer. I am pretty well convinced that I shall make out my case of movements as a protection against rain lodging on the leaves.2 As far as I have as yet made out M. albida is a splendid case.

I have had no time to examine more than one sp. of Eucalyptus.3 The seedlings of Lathyrus nissolia are very interesting to me;4 & there is something wonderful about them, unless seeds of 2 distinct leguminous species have got somehow mingled together. I have been thinking about Nepenthes, & about various expers which I have tried, & I cannot believe that cutting a hole in the pitcher wd prevent the Carb. of Amm. being absorbed at distant points; or the glands secreting.5 I wd certainly try again. If you have plenty of pitchers, cd you not dry one with blotting paper, & after from 6 to 18 hrs or whatever time you think best cut it longitudinally & gently open,! & surely you cd then see the points of secretion.

yours affectly | Ch. Darwin


Hooker had observed Mimosa albida at Kew, and had sent CD a specimen (letters from J. D. Hooker, [8 November 1872] and 17 [November 1873]). CD remarked on the insensitivity of the leaves to touch, and on the movement of the leaflets when the plant went to ‘sleep’ in Movement in plants, pp. 127, 380.
CD had been experimenting on the possible harmful effects of water on leaves (see letter to T. H. Farrer, 10 August [1873]). He did not include any of these observations in Movement in plants.
CD had received various specimens of Eucalyptus from Hooker (see letter to J. D. Hooker, [9 November 1873], and letter from J. D. Hooker, 17 [November 1873]).
CD described the movements of the stem of a young seedling of Lathyrus nissolia in Movement in plants, pp. 33–4.
CD had been advising Hooker on experiments on the digestive properties of Nepenthes (see letter to J. D. Hooker, 3 November [1873]).


Has been working hard on Mimosa albida. Could JDH ever make its opposite leaflets shut up close, as in sleep, when he irritated them? CD doubts they do, except in sleep. Thinks movement a protection against water.

Has examined only one specimen of Eucalyptus.

Cannot believe JDH’s results from cutting a hole in pitcher in his Nepenthes experiment.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 95: 306–7
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9158,” accessed on 20 March 2019,

Also published in The Correspondence of Charles Darwin, vol. 21