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Darwin Correspondence Project

To J. D. Hooker   23 July [1874]1

Down, | Beckenham, Kent.

July 23d

My dear Hooker.

Many thanks your very interesting & nice letter. Do just what you like with any or all of my materials.2 From the oldest primeval times it has been a delight to me to tell you what I have been doing, & have always felt as if the case was then as good as published; for I care for your interest on any point more than for that of the rest of the world.— Cephalotus seems as horrid a puzzle as Utricularia:3 as soon as my month’s holiday is over I shall grapple with it again, but God knows whether I shall succeed: I have thought of many dodges too long to detail & too visionary; but if any succeed I will of course tell you. Does rain accumulate in pitchers? If I were you, I would try in despair the effect of quasi-gnawing a bit of the inside of pitcher as by an insect: (mem. the gnawing of the labellum in some of the big Orchids)4 Nepenthes will turn out a great job, if the pitchers of different sp. act differently; & this does not seem very improbable, considering vast difference of Pinguicula & Utricularia.—5

I certainly shd like to see the great Drosera; but it is impossible as I leave early on Saturday morning for a month.6 The extreme outer tentacles become torpid before the others. If you might cut off a leaf, I wd insert it in weak infusion of raw meat; or perhaps you cd. do that to a leaf on the plant. If the structure is like that of D. rotundifolia it is marvellous that the functions shd. be different: I have found very little difference in any of the species examined by me, & almost confined to the manner of inflection of the blade of the leaf.7

Hereafter I shall be very glad to hear about the seeds in Nepenthes; look to state of any seedlings which grow. Your paper on N. will manifestly be too great & long an affair for my book & will well deserve a place in Tr. R. Soc.8

Ever yours affect | C. Darwin

Have you scratched with bristle for 10m inside of pitcher of Cephalotus? to see if excites secretion.—

If you get other sp. of Utricularia, will you keep it alive for me at Kew, & in any case preserve a few bladders in alcohol—& water.


The year is established by the relationship between this letter and the letter from J. D. Hooker, 22 July 1874.
Hooker had not observed digestion in the Australian pitcher-plant, Cephalotus (see letter from J. D. Hooker, 22 July 1874). CD’s initial observations on Utricularia vulgaris (common bladderwort) were also puzzling (see letter to J. D. Hooker, 16 July 1874).
CD refers to descriptions sent to him by Hermann Crüger, who observed bees of the genus Euglossa gnawing the fleshy protuberance of the labellum (large lip petal) in flowers of the orchid Catasetum (see Correspondence vol. 12, letter from Hermann Crüger, 21 January 1864 and n. 5; see also Orchids 2d ed., pp. 205–6).
Nepenthes is a genus of tropical pitcher-plants with numerous species. Pinguicula (butterwort) and Utricularia (bladderwort) are genera in the family Lentibulariaceae. Though CD was doubtful whether Utricularia was able to digest, he believed that Pinguicula could digest not only animal matter but seeds as well (see letter to W. T. Thiselton-Dyer, 23 June 1874, and letter to J. D. Hooker, 16 July 1874).
Hooker had offered to send a plant of Drosera whittakerii (now D. whittakeri, the scented sundew) that he had on loan from the Royal Botanic Gardens, Edinburgh (see letter from J. D. Hooker, 22 July 1874 and n. 9). CD was away from home from 25 July until 24 August 1874 (see ‘Journal’ (Appendix II)).
Hooker reported that the outer hairs of Drosera whittakerii did not curve in on an insect (see letter from J. D. Hooker, 22 July 1874). Drosera rotundifolia is the common or round-leaved sundew.
See letter from J. D. Hooker, 22 July 1874 and n. 6. Hooker did not publish his results on Nepenthes in Philosophical Transactions of the Royal Society of London, but see J. D. Hooker 1874a and 1874b.


JDH should do as he likes with insectivorous plant materials.

He has always thought telling JDH what he has been doing was as good as publishing.

Cephalotus seems as horrid a puzzle as Utricularia.

Nepenthes will turn out a great job if the pitchers of different species act differently. JDH’s paper on Nepenthes [Rep. BAAS 44 (1874): 102–16] is too long for CD’s book. Well deserves a place in Philosophical Transactions.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 95: 328–31
Physical description
6pp inc

Please cite as

Darwin Correspondence Project, “Letter no. 9560,” accessed on 20 June 2019,

Also published in The Correspondence of Charles Darwin, vol. 22