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Darwin Correspondence Project

To Daniel Oliver [17 September 1862]1

Cliff Cottage | Bournemouth

Wednesday Evening

Dear Oliver

I am sorry you had trouble of writing two notes,2 but I thank you sincerely for the flowers of Lythrum, which I shall carefully examine with great interest.3 Unless L. hyssopifolium presents 2 or 3 forms (which I do not believe) I am astounded at D. C. speaking of L. Graefferi as possibly the same as L. hyssop.4 They are totally unlike!— I am truly obliged for the specimens, for I feel a strange interest in this case. As you say it will be laborious to prove the case;5 but before I left home, I castrated marked, & fertilised in 18 methods above a hundred flowers, & protected them from insects.—6

I am much obliged for your Photograph.;7 I have none to match of myself, but I have one made by my son, which I will send when at home if you care to have it.8 Thanks, also, for diagram of Compositæ, in which the “&c.” means I fear that all cases are not represented.9 By chance the day before I was looking at the marygold & was puzzled by the apparently different stigma of the ray florets which, do not seem to produce seed.— But a man must be a Botanist to think about so gigantic an order: moreover it would be hardly possible to experiment by crossing.

Thanks again about Bolle or Rolle; which I will ascertain, when I get my copy from Lyell:10 I fancied from some remarks that he might be a Botanist; but my wife11 read it Rolle as well as I did.—

Having nothing on earth to do here, I have been working a little bit at the never-ending Drosera: as the glands absorb so readily & the Hairs move so rapidly under certain stimulants, it seemed a good opportunity to test how far this plant was sensitive to various vegetable substances, which are known to act energetically on the nervous system of animals.12 As yet I can make out no sort of rule; but the difference in action is very great. Thus, strychnine produces no effect; belladonna causes movement, as does veratrine; Henbane does not cause movement, but does not in the least check subsequent & immediate action of meat.— Opium on the other hand, does not cause movement, but afterwards meat instead of causing movement in less than one minute, does not act for 2, or 3 or 4 hours—it puts the plant to sleep! I wonder whether analogous experiments have been tried on other plants; but anyhow I shall go on, as it amuses me & passes the time.

But why do I waste your time?— I suppose for same reason it amuses me & passes the time, so forgive me & believe me, Yours very sincerely | C. Darwin


The date is established by the relationship to the letter from Daniel Oliver, 13 September 1862; the Wednesday following 13 September 1862 was 17 September.
Only one of the two letters referred to has been found (letter from Daniel Oliver, 13 September 1862). However, there is in DAR 142 an envelope addressed to CD in Oliver’s hand, which is postmarked ‘SP 16 62’ (London) and ‘SP 17 62’ (Poole and Bournemouth) (Calendar no. 13891f). This probably contained a letter and specimens sent in response to CD’s letter of 14 September [1862] (see n. 4, below); CD’s letter and Oliver’s letter of 13 September 1862 had apparently crossed in the post.
With his letter to Oliver of 14 September [1862], CD sent a dried specimen of the genus Lythrum for identification, and requested further dried specimens of the flower buds of that species. In a note in DAR 27.2 (ser. 2): 14, CD recorded that the specimen had been identified at the Royal Botanic Gardens, Kew, as L. Graefferi. The envelope of Oliver’s missing letter of 16 September 1862 (Calendar no. 13891f; see n. 2, above) is annotated in CD’s hand ‘Lythrum Graefferi’, and was preserved as a receptacle for several dried specimens of L. Graefferi, including that originally sent to Oliver by CD; the descriptions on the wrappers of most of the remaining thirteen specimens are in Oliver’s hand. However, since Oliver sent further specimens of the flowers of L. Graefferi in October (see letter to J. D. Hooker, 6 October [1862], and letter to Daniel Oliver, 13 October [1862]), it is impossible to identify which of the specimens were sent on this occasion. CD’s notes on the first set of specimens sent by Oliver are in DAR 27.2 (ser. 2): 15.
Candolle and Candolle 1824–73, 3: 82. Having learned that the Swiss botanist, Jean Pierre Etienne Vaucher considered Lythrum hyssopifolia to be dimorphic, CD had sought specimens of the plant from a number of correspondents (see letter to C. C. Babington, 2 September [1862]), obtaining fresh specimens from Oliver and dried specimens from Sarah Elizabeth Wedgwood early in September 1862 (see letter to Daniel Oliver, 14 September [1862] and nn. 2 and 3).
See letter from Daniel Oliver, 13 September 1862.
See letter to Daniel Oliver, 29 [July 1862] and n. 6.
The photograph of Oliver has not been found. The photograph may have been the same as the carte-de-visite by Maull & Polyblank that is reproduced in this volume; that photograph has been dated to the years 1856–65 by reference to the period during which Maull & Polyblank were in partnership.
William Erasmus Darwin’s portrait of CD is reproduced as the frontispiece to Correspondence vol. 9.
See letter from Daniel Oliver, 13 September 1862.
CD had apparently asked Oliver whether he had heard of the German geologist and palaeontologist, Friedrich Rolle; Oliver replied in his letter of 13 September 1862 that he had not, but wondered whether CD was referring to the German dendrologist and ornithologist, Carl August Bolle. CD’s question was probably prompted by his having received a copy of the first part of Rolle 1863, which he had subsequently lent to Charles Lyell (see letter to Charles Lyell, 1 October [1862] and n. 2).
Emma Darwin.
CD began to observe the effects of various substances on the insectivorous plant, Drosera rotundifolia, in 1860 (see Correspondence vol. 8). He had hoped to continue and complete the experiments in the summer of 1861, but subsequently decided to postpone them (see Correspondence vol. 9, letter to J. D. Hooker, 4 February [1861], and letter to Daniel Oliver, 11 September [1861]); he carried out a small number of experiments in May 1862 (see the observational notes dated 18 and 21 May 1862 in DAR 54: 74–5). There are notes detailing his extensive experiments with the species between 14 and 26 September 1862 in DAR 54: 29–49; on 17 September, CD carried out a set of experiments with the substances described in this letter. See also letter to J. D. Hooker, 26 September [1862]. CD’s work on this subject was not published until 1875 (Insectivorous plants).


Performed a large number of Lythrum crosses before leaving home.

Working on Drosera for amusement. Has tried effect on plants of vegetable substances active on animal nervous systems, e.g., opium; makes Drosera inactive for hours.

Letter details

Letter no.
Charles Robert Darwin
Daniel Oliver
Sent from
Source of text
DAR 261 (DH/MS 10: 36)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 3709,” accessed on 27 April 2017,

Also published in The Correspondence of Charles Darwin, vol. 10