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Darwin Correspondence Project

To J. D. Hooker   25 March [1874]1

Down, | Beckenham, Kent.

March 25

My dear Hooker

I am glad to hear about the Hedychium, & how soon you have got an answer!2 I hope that the wings of the Sphinx will hereafter prove to be bedawbed with pollen, for the case will then prove a fine bit of prophecy from the structure of a flower to special & new means of fertilisation.3 By the way I suppose you have noticed what a grand appearance the plant makes when the green capsules open, & display the orange & crimson seeds & interior, so as to attract birds, like the pale buff flowers to attract dusk-flying Lepidoptera. I presume you do not want seeds of this plant, as I have plenty from artificial fertilisation.—

I have been working so hard at that accursed Descent of Man,4 that I have done nothing & read nothing,—not even H. Spencer’s answer. George says that he does not think that H. S. has answered all Molton’s objection on physical grounds, & he cannot judge on other points.5 I have not yet read Croll, & have heard nothing about Carter & the Eoozoon.6 I infer that Eoozoon is done for: good Heavens how difficult it is to know what to believe! Belt I have read, & I am delighted that you like it so much.7 It appears to me the best of all the Nat. Hist. Journals which have ever been published. I have written to Fritz Müller to tell him to observe the leaf-carrying ants, & the mould generated on the chopped leaves: by opening the stomachs of the larvæ, he could soon make out the nature of their food.8

I hope to finish Descent in about ten days & then after a little rest I hope to resume Drosera & glaucous leaves.—9 I am now trying a lot of plants, divided into 2 lots; one of which I am feeding with meat & the other not. Half a century ago the nurseryman Knight said the same thing as Lady Dorothy’s gardener about Dionæa.10 B. Sanderson is going to lecture about Dionæa at R. Institution in May, & I have sent him my M.S, for him to be able to say a little about the general habits of the plants.—11 I fear you cannot possibly do anything about Nepenthes; but I hope Dyer does.12

I am so weary of correcting & adding to old work, that I long to be at new work.13

You give a wretched account of all your belongings; those infectious complaints are most bothersome; & I am very sorry to hear about your sister.14 We have here a poor household,— George & Horace in a poor state of health & can do nothing.15

There are many troubles in this life.—

If you can conveniently, do come here for a Sunday—

Dear old friend | Yours affecty. | Ch. Darwin

Your letter, as usual, told me lots of news.—


The year is established by the relationship between this letter and the letter from J. D. Hooker, 24 March 1874.
Sphinx or hawk-moths are essential for fertilising the Asian lilies in the genus Hedychium, which are almost sterile without the aid of insects (see Cross and self fertilisation, p. 364). CD conjectured that the extremely exserted stamens of the flowers of Hedychium would allow the pollen to come into easy contact with the wings of moths. His conjecture was later confirmed (Zomlefer 1994).
CD had been working on the second edition of Descent since the end of November 1873 (see Correspondence vol. 21, Appendix II).
See letter from J. D. Hooker, 24 March 1874 and n. 14. George Howard Darwin was commenting on Herbert Spencer’s defence of his claim to have given a priori proof of the laws of motion (Spencer 1873). John Fletcher Moulton, in an anonymous review, had contested Spencer’s view that the laws of motion could be arrived at without experimental evidence ([Moulton] 1873). Spencer discussed ‘physical truths’ in Spencer 1873c, pp. 736–9.
For the papers by James Croll and Henry John Carter, see the letter from J. D. Hooker, 24 March 1874 and nn. 12 and 13. CD had accepted that Eozoon canadense was a fossil foraminifer (see Origin 4th ed., p. 371), although disputes about its nature led him to modify his statement in Origin 6th ed., p. 287. The inorganic nature of Eozoon canadense was not conclusively established until the 1890s (see O’Brien 1970).
CD refers to Thomas Belt’s The naturalist in Nicaragua (Belt 1874).
See letter to Fritz Müller, 1 January 1874, in which CD made this request and informed Müller that he was sending him a copy of Belt 1874. Belt discussed leaf-carrying ants in Belt 1874, pp. 80–1.
CD finished working on Descent 2d ed. in early April (see letter to R. F. Cooke, 8 April 1874 and n. 1), and by 12 April he was again carrying out experiments on the digestion of Drosera (sundews; see letter to Edward Frankland, 12 April 1874). CD had begun studying the effects of water on plants with glaucous leaves (those covered in a waxy substance called bloom) in August 1873 (see Correspondence vol. 21, letter to J. D. Hooker, 13 August 1873 and n. 2). He carried out experiments to compare the effects of water on berries and leaves with the bloom left on and on those that had the bloom removed (see DAR 66: 8, 24).
Dorothy Fanny Nevill’s gardener had observed that Dionaea (Venus fly trap) plants fed with meat were superior to those not fed in this manner (see letter from J. D. Hooker, 24 March 1874 and n. 16). In Insectivorous plants, p. 301 n., CD noted that a similar experiment had been made before 1818 by the nurseryman Joseph Knight.
Hooker and William Turner Thiselton-Dyer were carrying out experiments for CD on the digestion of Nepenthes (the tropical pitcher-plant), but had come to a halt in November 1873 owing to shortage of time (see Correspondence vol. 21, letter from J. D. Hooker, 25 November 1873 and n. 4).
CD had spent the first three months of 1874 working on Descent 2d ed. (‘Journal’ (Appendix II)) and Coral reefs 2d ed. (see letter to Smith, Elder & Co, 8 January 1874, and letter to J. D. Hooker, 27 [March 1874]).
Hooker’s youngest children were suffering from whooping cough and an older son had measles; his sister Elizabeth Evans-Lombe had been an invalid for many years (see letter from J. D. Hooker, 24 March 1874 and nn. 3, 5, and 6).
George Howard Darwin’s ill health had forced him to give up his plans to practise as a barrister (see ODNB; his decision is recorded in the letter from Emma Darwin to H. E. Litchfield, [24] April 1873 (DAR 219.9: 101), and the letter from Emma Darwin to Horace Darwin, [25 April 1873] (DAR 258: 574)). CD also refers to Horace Darwin.


Thanks for information about Hedychium. Hopes wings of Sphinx will be found covered with pollen for that will be a fine bit of prophecy from the structure of a flower to special and new means of fertilisation.

Has been at Descent so hard he has done nothing, not even H. Spencer’s answer.

Has not yet read Croll ["Ocean currents", London Edinburgh & Dublin Philos. Mag. 47 (1874): 94–122, 168–90].

Has heard nothing about Carter and Eozoon. Eozoon, he infers, is done for.

Has read Belt [The naturalist in Nicaragua (1874)]: best of all natural history travel books.

Has written to Fritz Müller about leaf-carrying ants.

Hopes to resume work on Drosera.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 95: 317–19
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9372,” accessed on 24 March 2019,

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