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Darwin Correspondence Project

To J. D. Hooker   13 June [1864]

Down Bromley Kent

June 13

My dear Hooker

Many thanks for yr photograph which we were both glad to get.1 It is an excellent one & to my mind gives your character better than any one I have seen. I enclose 2 more of mine for Oliver & Thwaites.2 Funnily enough the boys declared it was like Moses.3 I return Harveys letter as I suppose you mean to keep it otherwise I would.4 Stir him up to publish on this & Dandelion—;5 Ovules of latter differ.

If I can lay my hands on a specimen I will enclose a head. With respect to Oxlip I strongly suspect that the uniform P. elatior is really a distinct species but I will try next spring & perhaps publish a little paper on the subject.6

Many thanks for offer about ship for Scott.7 He has just sent a curious paper on sterility of Passiflora;8 it will ultimately prove that nothing is so variable as the reproductive function. You told me Decaisne said that Delphinium is not crossed.—9 I have now found that the flowers of D. consolida artificially fertilised under a net produce twice as many seed as the untouched flowers under the same net.

You are a real good man to talk of coming here soon10

yours affectionately | C Darwin

I doubt whether I shall get a young Vanilla from Veitch:11 if you can lend or give me a growing one it will be a priceless treasure

Can the Dandelion case have any relation to the difference of achenia in certain genera in ray & central florets?12


Hooker probably sent the photograph that appears in Correspondence vol. 7, facing page 90. The photograph has not been found in the Darwin Archive–CUL.
Daniel Oliver and George Henry Kendrick Thwaites. See letter from J. D. Hooker, [11 June 1864].
Hooker had enclosed a letter from William Henry Harvey in his letter of [11 June 1864].
See letter from W. H. Harvey, 19 May 1864 and n. 4, letter to J. D. Hooker, 10 June [1864] and n. 14, and enclosure to letter from J. D. Hooker, [11 June 1864].
See letter to J. D. Hooker, 10 June [1864] and n. 17. Henry Doubleday had first called CD’s attention to the existence of a form of oxlip (Primula elatior) distinct from the common oxlip in 1860, and had supplied him with seedlings (see Correspondence vol. 8, letter from Henry Doubleday, 3 May 1860, CD’s notes in DAR 108: 32, and ‘Specific difference in Primula, p. 449). This form was named the Bardfield oxlip (P. elatior) after its discovery in swampy meadows in Bardfield, Essex, and its range was restricted to two or three eastern counties of England. CD’s crossing experiments established that P. elatior was a distinct species and not a hybrid form (see ‘Specific difference in Primula, pp. 449–51, and Forms of flowers, pp. 32–4, 72–3). There are notes on the Bardfield oxlip, dated 1865 and 1866, in DAR 108: 8–10 and 32 v.
CD refers to John Scott. See letter from J. D. Hooker, [11 June 1864].
Scott 1864d. See first letter from John Scott, 10 June [1864] and n. 2.
CD refers to Joseph Decaisne. Hooker had informed CD of Decaisne’s view, presented in Decaisne 1863, pp. 10–11, that the flowers of Delphinium, or larkspur, self-pollinate in the bud, and do not normally intercross (see Correspondence vol. 11, letter from J. D. Hooker, [31 July 1863]). CD disputed this point in his letter to Hooker of 12–13 August [1863] (Correspondence vol. 11). In Variation 2: 21, he reported his experiments with D. consolida that indicated that the plant was more fertile when crossed. He documented subsequent observations in Cross and self fertilisation, pp. 129–30, noting that Delphinium flowers were frequently visited by humble-bees, and were structurally adapted for cross-pollination by insects.
CD refers to James Veitch (1815–69), who owned a nursery in Chelsea. See letter to J. D. Hooker, 10 June [1864].
See letter from W. H. Harvey, 19 May 1864 and n. 4.


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

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

Decaisne, Joseph. 1863. De la variabilité dans l’espèce du poirier; résultat d’expériences faites au Muséum d’histoire naturelle de 1853 à 1862 inclusivement. Comptes rendus hebdomadaires des séances de l’Académie des sciences 57: 6–17. [Reprinted in Annales des sciences naturelles (botanique) 4th ser. 20: 188–200.]

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

‘Specific difference in Primula’: On the specific difference between Primula veris, Brit. Fl. (var. officinalis of Linn.), P. vulgaris, Brit. Fl. (var. acaulis, Linn.), and P. elatior, Jacq.; and on the hybrid nature of the common oxlip. With supplementary remarks on naturally produced hybrids in the genus Verbascum. By Charles Darwin. [Read 19 March 1868.] Journal of the Linnean Society (Botany) 10 (1869): 437–54.

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


W. H. Harvey’s dandelion case worth publishing.

Suspects the uniform Primula elatior JDH referred to is a distinct species.

Scott’s paper on Passiflora shows variability of reproductive systems.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 115: 239
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 4531,” accessed on 19 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 12