To Friedrich Hildebrand   25 June [1864]1

Down. | Bromley. | Kent. S.E.

June 25

Dear Sir

I am much obliged for your letter & for your great kindness in sending me the Orchids. They closely resemble English specimens & the 2 stigmas still appear to me distinct tho’ so close.2 I will with the greatest pleasure send you any papers I may publish.3 But I am now only slowly recovering my strength after a nine month’s illness & have only just recently begun to write. I have seen no one for very many months & therefore had not heard of the death of Prof. Treviranus4

I have written a paper on Lythrum which when printed will I think interest you.5 When you publish on Pulmonaria officinalis, I hope you will send me a copy or inform me where it is published; for this genus interests me much.6 You will be surprized to hear that I have some long-styled seedlings with no other form & these tho’ protected from insects have produced a very few seeds.7 I have made many experiments on Pulmonaria angustifolia with well-marked, but rather complex, results; but perhaps I shall not publish till my experiments are repeated next year.8

I believe I know to what you refer about Salvia & there is not a more curious contrivance, I think, in the vegetable kingdom; it is well worth describing, not that I intend to do so.9

With sincere thanks & respect believe me Dear Sir | yours very faithfully | Charles Darwin

LS

1
The year is established by the reference to the letter from Friedrich Hildebrand, 21 June 1864.
2
See letter from Friedrich Hildebrand, 21 June 1864 and nn. 2 and 3. In his review of Orchids, Hildebrand’s colleague Ludolph Christian Treviranus had claimed that the stigmas of Orchis pyramidalis were joined together, rather than separated as in CD’s diagram (see Orchids, p. 22, and Treviranus 1863c, p. 243; see also ‘Fertilization of orchids’, p. 141 (Collected papers 2: 139), and Orchids 2d ed., p. 24 n.).
3
Hildebrand’s name is on the presentation lists for ‘Three forms of Lythrum salicaria’, Variation, ‘Illegitimate offspring of dimorphic and trimorphic plants’, Cross and self fertilisation, Insectivorous plants, and Movement in plants (see Correspondence vol. 12, Appendix III and DAR 210.11: 23, 28, 29, 33).
5
CD refers to ‘Three forms of Lythrum salicaria’. See letter from Friedrich Hildebrand, 21 June 1864 and n. 7.
6
See letter from Friedrich Hildebrand, 21 June 1864 and n. 11. Hildebrand’s observations on Pulmonaria officinalis were published in Hildebrand 1865, pp. 13–15. An annotated copy of the paper is in the Darwin Pamphlet Collection–CUL. See also letter to J. D. Hooker, 10 December [1864] and n. 19.
7
See letter from L. C. Wedgwood, [6 June 1864] and n. 5, and letter from Friedrich Hildebrand, 21 June 1864 and n. 11. Hildebrand’s observations of Pulmonaria officinalis indicated that the long-styled form was self-sterile; however, CD’s observations suggested that the plant was self-fertile. CD continued his observations of P. officinalis for several years, and reported his conclusions in Forms of flowers, pp. 101–4 (see also his notes in DAR 110: A44 v., A55). In ‘Illegitimate offspring of dimorphic and trimorphic plants’, pp. 430–1, CD expressed doubt whether his specimens of P. officinalis were of the same species as those described by Hildebrand.
8
CD began crossing different forms of Pulmonaria angustifolia in June 1864, and by July had concluded that the long-styled form was self-sterile (see DAR 110: A48, A54, ‘Illegitimate offspring of dimorphic and trimorphic plants’, pp. 430–1, and Forms of flowers, pp. 107–10). For CD’s preliminary investigations of P. angustifolia, see, for example, letter from W. E. Darwin, 14 April [1864] and n. 1, and letter to W. E. Darwin, 14 May [1864].
9
See letter from Friedrich Hildebrand, 21 June 1864 and n. 9. In Hildebrand 1866, Hildebrand described variable mechanisms in different Salvia species that facilitated pollination; these involved movements of the anthers and sometimes of the pistil caused by insects landing on the flowers; see especially CD’s annotations on pp. 15 and 16 of his heavily annotated copy of Hildebrand 1866 in the Darwin Pamphlet Collection–CUL. CD referred to the ‘admirable mechanical adaptations in this genus for favouring or ensuring cross-fertilisation’ in Cross and self fertilisation, p. 93 n., citing the work of Hildebrand and others. See also letter to Friedrich Hildebrand, 16 May [1866], Calendar no. 5092.

Please cite as “DCP-LETT-4545,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-4545