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Darwin Correspondence Project

To T. H. Farrer   28 May [1870]1

Down. | Beckenham |Kent. S.E.

May 28th

My dear Farrer

I suppose I must have known that the stamens reversed their former position in Berberis, for I formerly tried experiments with anæsthetics, but I had forgotten the fact, & I quite agree with you that it is a sound argument that the movement is not for self-fertilisation.2 The N. American barberries (mahonia) offer a good proof to what an extent natural crossing goes on in this genus; for it now almost impossible in the country to procure a true specimen of the 2 or 3 forms originally introduced—3

I hope the seeds of Passiflora will germinate, for the turning up of the pendent flower must be full of meaning.4 I am so glad that you are able to occupy yourself a little with flowers: I am sure it is most wise in you for your own sake & children’s sake.—5

Some little time ago Delpino wrote to me praising the Swedish book on the fertilisation of plants; as my son George can read a little Swedish, I shd like to have it back for a time just to hear a little what it is about, if you wd. be so kind as to return it by book Post.—6

I am going steadily on with my experiments on the comparative growth of crossed & self fertilised plants, & am now coming to some curious anomalies & some interesting results.7 I forget whether I showed you any of them when you were here for a few hours.—8 You ought to see them; as they explain at a glance why nature has taken such extraordinary pains to ensure frequent crosses between distinct individuals.

If in the course of the summer, you shd. feel any inclination to come here for a day or two, I hope that you will propose to do so, for we shd. be delighted to see you; though, as you know, I can talk with no one except for a very short time.—

Pray believe me | yours very sincerely | Ch. Darwin

P.S | I remember years ago being surprised at observing that the pollen in the genus Hedaroma (or Darwinia)9 is almost liquid viscid, & this seemed to me deserving examination. The plant is also rather ornamental & curious.


The year is established by the relationship between this letter and the letter from T. H. Farrer, 26 May 1870.
See letter from T. H. Farrer, 26 May 1870 and n. 4. No record of the experiments CD mentions has been found.
Species of Mahonia native to western North America were introduced to Europe in the 1820s (Ross and Auge 2008, p. 22).
CD alludes to the recent death of Farrer’s wife, Frances Farrer (see letter from T. H. Farrer, 17 May 1870).
CD refers to Federico Delpino’s remarks on Johan Severin Axell’s monograph, Axell 1869 (see letter from Federico Delpino, 20 May 1870 and n. 7). CD had lent his copy to Farrer (see Correspondence vol. 17, letter to Federico Delpino, 14 October 1869 and n. 8). CD also refers to George Howard Darwin.
CD refers to his research for Cross and self fertilisation.
The last known visit by Farrer to Down House was sometime shortly before 9 October 1869 (see Correspondence vol. 17, letter from T. H. Farrer, 9 October 1869 and n. 6).
Hedaroma is now subsumed within Darwinia, a genus of Australian plants in the family Myrtaceae.


Axell, Severin. 1869. Om anordningarna för de fanerogama växternas befruktning. Stockholm: Iwar Hæggströms Boktryckeri.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.


Fertilisation of barberries.


Is continuing his experiments on the comparative growth of crossed and self-fertilised plants.

Letter details

Letter no.
Charles Robert Darwin
Thomas Henry Farrer, 1st Baron Farrer
Sent from
Source of text
Linnean Society of London (LS Ms 299/14)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7205,” accessed on 25 February 2021,

Also published in The Correspondence of Charles Darwin, vol. 18