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Darwin Correspondence Project

To Isaac Anderson-Henry   20 January [1863]1

Down, Beckenham, Kent. S.E.

Jan. 20th. 1863.

Dear Sir,

I thank you cordially for your singularly kind letter.2 But your kindness leads me to overrate what I have done in Natural history.— I was much surprised at the appearance of the leaf of the hybrid strawberry;3 and was much tempted to accept your kind offer and declined only on reflection, that as my health is weak and I have many other points to attend to, I feared I should have neglected your specimen. Perhaps you will be so good as to inform me whether this hybrid produces next spring fertile seeds. If I understand right the supposed progeny from the strawberry and raspberry have not yet fruited: but if this be really a cross you will indeed have effected a prodigy, and it will be very curious if you cross Blackberry and Raspberry;4 I shall much like to hear the result. I may mention that this past spring I tried again the crosses on Primula with the same result rather more strongly marked; and I have gone on, now for three generations breeding them what I call homomorphically, with some curious results, which I shall publish whenever I have time.5 I have sent a paper on Linum to the Linnæan Society;6 when it is published I will do myself the pleasure of sending to you a copy; and it will I should think be in good time for your experiments.7 I cannot say how glad I am that you will make some experiments on the subject.

It does not absolutely follow in making a cross between distinct species, that the same rules would follow in the fertility of the pollen. I hope that you will try and mark separately (excluding insects, as you know better than I do, the necessity) the two kinds of pollen of one species on the stigma of the other; and see in making hybrids what the difference is in fertility, and in the character of the hybrid seedlings. This would be an entirely new field for observation and discovery. You will see in my paper that some species of Linum are not dimorphic, and are self-fertile; and so it is in some other genera.—8 You refer to L. rubrum; I am not a Botanist and have called one of the species on which I have experimented L. grandiflorum, which is crimson and not uncommon in flower gardens; I hope I have not made a mistake in name.—9

You most kindly permit me to mention any point on which I want information. If you are so inclined, I am curious to know from systematic experiments, whether Mr. D. Beaton’s statement that the pollen of two shortest anthers of scarlet Pelargonium produce dwarf plants, in comparison with plants produced from same mother-plants by the pollen of longer stamens from same flower.10 It would aid me much in some laborious experiments on Melastomas.11 I confess I feel a little doubtful: at least I feel pretty nearly sure that I know the meaning of short stamens in most plants. This summer (for another object) I crossed Queen of Scarlet Pelargonium with pollen of long and short stamens of Multiflora alba, and it so turns out that plants from short-stamens are the tallest; but I believe this to have been mere chance.—12 My few crosses in Pelargonium were made to get seed from the central peloric or regular flower (I have got one from peloric flower by pollen of peloric); and this leads me to suggest that it would be very interesting to test fertility of peloric flowers in three ways, own peloric pollen on peloric stigma—common pollen on peloric stigma—peloric pollen on common stigma of same species. My object is to discover whether with change of structure of flower there is any change in fertility of pollen or of female organs. This might, also, be tested by trying peloric and common pollen on stigma of a distinct species, and conversely.13 I believe there is a peloric and common variety of Tropæolum; and a peloric or upright and common variation of some species of Gloxinia.—14 And the medial peloric flowers of Pelargonium; and probably others unknown to me.—

To recur to Linum; if you cross distinct species, it would, I think be advisable to take two dimorphic species; and not one dimorphic and the other self-fertile. I have reason to suspect L. trigynum is dimorphic but it has not yet flowered with me.—15

Your kindness has led me to trespass at unreasonable length on your time, and, | I remain dear Sir, | yours truly obliged. | Ch. Darwin.

P.S. I thank you for your most kind invitation, which I fear I shall never profit by.—16

P.S. Have you any quite sterile Hybrid plant with a rather large stigma, (and of which I could procure either one or both pure parent flowers) as I very much wish to compare by dissection certain minute parts of stigma: if so, and you would have great kindness to send me by Post in a little tin box some flowers, it would be a very great favour.17


The text of the letter is taken from a copy commissioned by Francis Darwin for his editions of CD’s letters; part of the letter was published in ML 2: 297–8. The copyist dated the letter 20 January 1863; however, when Francis edited the transcription he added pencil brackets to indicate that the year had been added by the copyist and was not present in the original letter. The year is confirmed by the relationship between this letter and the letter from Isaac Anderson-Henry, 17 January 1863.
In his letter of 17 January 1863, Anderson-Henry informed CD that he had hybridised the raspberry and strawberry, resulting in ‘one brood of plants with wiry foliage some having 4 divisions in the leaf’.
In his letter of 17 January 1863, Anderson-Henry informed CD that this ‘coming Season’ he planned to attempt a cross between ‘the Bramble & raspberry’.
CD first published an account of Primula in 1862 (‘Dimorphic condition in Primula). CD’s subsequent experimental results on homomorphic crosses in Primula (that is, crosses between plants of the same species with the same flower forms) were discussed in ‘Illegitimate offspring of dimorphic and trimorphic plants’. His notes on these experiments are preserved in DAR 108, 110, and 111. CD also suggested additional Primula experiments to John Scott, encouraging him to publish the results (see, for instance, Correspondence vol. 10, letter to John Scott, 3 December [1862], and Scott 1864a).
See letter from Isaac Anderson-Henry, 17 January 1863. Anderson-Henry’s name appears on CD’s presentation list for ‘Two forms in species of Linum (see Correspondence vol. 11, Appendix IV).
Linum grandiflorum is the name CD used for this plant both in ‘Two forms in species of Linum and in Forms of flowers.
Donald Beaton was a regular contributor to the Journal of Horticulture; the reference is to Beaton 1861, pp. 312–13. See also Beaton 1860, pp. 254–5, and Correspondence vol. 9, letters to Journal of Horticulture, [17 May 1861] and [before 9 July 1861], and letters to J. D. Hooker, 14 May [1861] and 18 [May 1861]. See Appendix V for Beaton’s responses to CD in the Journal of Horticulture in 1863.
CD continued his study of the Melastomataceae, begun in 1861, in January 1863 (see letter to Hugh Falconer, 5 [and 6] January [1863] and n. 22).
CD conducted a series of crosses with different varieties of Pelargonium in May 1862 (see Correspondence vol. 10, letter to Daniel Oliver, 8 June [1862], and letter to Asa Gray, 1 July [1862]). CD’s notes on these experimental crosses are preserved in DAR 51: B4–13. See also the annotated article on pelargoniums in CD’s copy of the Gardeners’ Chronicle, 15 February 1862, pp. 139–40, which is in the Cory Library, Cambridge Botanic Garden.
These experiments on regular (peloric) flowers found on the same plant with primarily irregular flowers, were discussed in Variation under the subheading ‘Monstrosities as a cause of sterility’ (Variation 2: 167).
CD also discussed the peloric Tropaeolum with Charles William Crocker, a former gardener at the Royal Botanic Gardens, Kew (see Correspondence vol. 10, letter from C. W. Crocker, 24 November 1862 and n. 4). The Gloxinia referred to was G. speciosa (Variation 1: 365 and 2: 167). See also Correspondence vol. 10, letter to John Scott, 19 December [1862].
CD discussed the crossing of dimorphic Linum species in Forms of flowers, pp. 81–101. See ibid., p. 100, for a discussion of L. trigynum.
Anderson-Henry invited CD to pay him a visit if he ever came to Scotland (see letter from Isaac Anderson-Henry, 17 January 1863).
In his letter to John Scott of 21 January [1863], CD stated that he wished to observe the state of the tissues of the stigma of a sterile hybrid for comparison with ‘the same in fertile parent-species’, in order to show the ‘difference in female organs of hybrid and pure species’.


Beaton, Donald. 1860. Crossing flowers. Cottage Gardener 24: 253–5.

Beaton, Donald. 1861. Fertilisation of wheat. Journal of Horticulture n.s. 1: 311–13.

Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

‘Dimorphic condition in Primula’: On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations. By Charles Darwin. [Read 21 November 1861.] Journal of the Proceedings of the Linnean Society (Botany) 6 (1862): 77–96. [Collected papers 2: 45–63.]

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

‘Illegitimate offspring of dimorphic and trimorphic plants’: On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. By Charles Darwin. [Read 20 February 1868.] Journal of the Linnean Society of London (Botany) 10 (1869): 393–437.

ML: More letters of Charles Darwin: a record of his work in a series of hitherto unpublished letters. Edited by Francis Darwin and Albert Charles Seward. 2 vols. London: John Murray. 1903.

‘Two forms in species of Linum’: On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. By Charles Darwin. [Read 5 February 1863.] Journal of the Proceedings of the Linnean Society (Botany) 7 (1864): 69–83. [Collected papers 2: 93–105.]

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Discusses hybrid strawberry–raspberry

and his research on Primula and Linum.

Suggests breeding experiments.

Doubtful about Donald Beaton’s statement about Pelargonium.

Mentions experiments on peloric flowers.

Letter details

Letter no.
Charles Robert Darwin
Isaac Anderson/Isaac Anderson Henry
Sent from
Source of text
DAR 145: 1
Physical description
C 6pp

Please cite as

Darwin Correspondence Project, “Letter no. 3929,” accessed on 5 February 2023,

Also published in The Correspondence of Charles Darwin, vol. 11