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Darwin Correspondence Project

To T. H. Farrer   10 October [1869]1

Down. | Beckenham | Kent. S.E.

Oct 10

My dear Farrer

I declare I am almost as sorry as if I had been myself forestalled, indeed more so for I am used to it. It is, however, a paramount, though bothersome duty in every naturalist to try & make out all that has been done by others on his subject.

By all means publish next summer your confirmation & a summary of Delpino’s observations, with any new ones of your own.— Especially attend about the nectary exterior to the staminal tube.— This will in every way be far better than writing to Delpino.—2

It wd not be at all presumptuous in you to criticise Delpino.— I am glad you think him so clever; for so it struck me.—

Look at hind legs yourself of some Humble & Hive-bees; in former take a very big individual (if any can be found) for these are the females, the males being smaller & they have no pollen-collecting apparatus. I do not remember where it is figured, probably in Kirby & Spence,3—but actual inspection better.— That is good idea about corona of Passiflora— I remember something analogous, but exactly what I cannot call to mind.— Still better, your idea about Antirrhinum, if true4 Could you experimentise with any coloured powder?

I rather think Antirrhinum is self-fertile, when insects are excluded,— I know I have the result in my notes; & which I will attend to when I go through them in course of winter.—5

Please do not return any of my Books, until all are finished, & do not hurry.—6

I feel certain that you will make fine discoveries.—

Yours very sincerely | C. Darwin

P.S I sent paper by Post on Martha7


The year is established by the relationship between this letter and the letter from T. H. Farrer, 9 October 1869.
See letter from T. H. Farrer, 9 October 1869 and nn. 2 and 3. Farrer had been studying many of the plant species discussed in recent publications of Federico Delpino. Farrer did not publish a summary of Delpino’s observations, but did eventually publish a revised version of the paper he evidently sent to CD (see Farrer 1872, p. 478).
CD refers to Kirby and Spence 1815–26, but the illustration he refers to has not been found. The description of the absence of the corbicula or pollen-basket in males is in ibid., 2: 118.
Most of CD’s surviving notes on the self-fertility of Antirrhinum majus (the snapdragon) concern experiments with artificially pollinated specimens (DAR 51: B18–21). For CD’s published observations on the self-fertility of Antirrhinum, see Cross and self fertilisation, p. 363.
CD refers to ‘Ueber die Befruchtung der Martha (Posoqueria?) fragrans’ by Fritz Müller (F. Müller 1866), in which Müller described the mechanism by which Martha fragrans (now Posoqueria densiflora) prevented self-fertilisation. CD’s copy of the paper is in the Darwin Pamphlet Collection–CUL.


Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.

Farrer, Thomas Henry. 1872. On the fertilisation of a few common papilionaceous flowers. Nature, 10 October 1872, pp. 478–80, and 17 October 1872, pp. 498–501.


Sympathises with THF at being forestalled by Delpino, but urges him to publish confirmation.

Letter details

Letter no.
Charles Robert Darwin
Thomas Henry Farrer, 1st Baron Farrer
Sent from
Source of text
Linnean Society of London (LS Ms 299/17)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6930,” accessed on 20 October 2019,

Also published in The Correspondence of Charles Darwin, vol. 17