To Daniel Oliver   24 July [1862]1

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

July 24th

Dear Oliver

My poor Boy rallied last night & the Doctors think he has passed the crisis & is out of danger.—2 I have had a miserable month, & many of my experiments on Dimorphism are gone to the dogs.3

I am very glad that your Lectures are nearly over, & that you will be a somewhat free man.—4 It must be very hard work. Asa Gray seems to be able to do nothing else when he is lecturing.5 He is now free & has been making some capital observations on orchids. He has got a self-fertilising Platanthera just like the Bee, with thin caudicle, but still more plainly than the Bee with adaptations for an occasional cross.6 I think, in opposition to you, that some day the Bee-ophrys will be explained; I have been speculating, against evidence, that arachnites may be the crossing form & the Bee the self-fertilising form of same species; but it won’t do.—7

Many thanks for your reference to Duchartre.8 The Vanda must be something curious.9 By the way I find that the orchid mentioned by me as Mormodes unnamed sp. is Cycnoches ventricosum:10 it is hermaphrodite & I wish much to see a dark Cynoches, of which I once received a flower from Kew, for I believe it to be a male.11 Will you ask Mr H. Gower12 whether he could spare me one, when it flowers again.

Many thanks for Bot.-Zeitung: it will be very useful.—13 Dont take trouble about the Primula; if you stumble on it, I shd. like to see it.14 Cytisus adami is a strange puzzle; I have failed in fertilising C. purpureus by pollen of common Laburnum.—15

If you can spare the time to notice my orchid Book, I have not the least doubt you will do it right well. There was capital matter in your Review of my Primula paper.—16 I am always astonished at your knowledge.

Farewell— I am tired so no more. I hope you will enjoy your holidays & be idle | Yours very sincerely | C. Darwin

If you can remember, please remember that I want any peloric plants for experiments; ie any in pots, which could be lent me from Kew.— I have been working at peloric pelargoniums; but whether I shall get any good result, I know not.17

1
The year is established by the references to Leonard Darwin’s illness (see n. 2, below) and to [Oliver] 1862c.
3
In his ‘Journal’ (see Correspondence vol. 10, Appendix II), CD wrote, ‘Much time wasted June & July from Leonards illness’. On CD’s experiments, see, for instance, the letters to J. D. Hooker, 30 May [1862] and n. 7, and 23 June [1862] and n. 4, the letter to Alphonse de Candolle, 17 June [1862] and n. 2, and the letter to M. T. Masters, 8 July [1862] and n. 3.
4
Oliver was professor of botany at University College London.
5
See letters from Asa Gray, [2 June 1862], [late June 1862], and 2–3 July 1862. Gray was Fisher Professor of natural history at Harvard University and lectured at the Lawrence Scientific School (Dupree 1959).
6
Gray sent CD notes on this subject with the letter from Asa Gray, 2–3 July 1862; the notes have not been found, but see the letter to Asa Gray, 23[–4] July [1862] and nn. 23–4.
8
Duchartre 1862. Oliver’s letter has not been found; however, there is a note in CD’s hand, recording this reference, in DAR 70: 161. The note is pasted on a second piece of paper, which bears the annotation: ‘M. D— has given a full historical account of the form of Catasetums | (I doubt whether worth geting)’. CD cited this paper in Orchids 2d ed., p. 196 n.
9
Pierre Etienne Simon Duchartre’s paper, which discussed the different kinds of polymorphism in orchids, included an account of Vanda Lowei, a Sumatran orchid in which the flowers at the base of each spike are consistently different in colour and form from the rest of the flowers on the spike (Duchartre 1862, pp. 118–22). Duchartre suggested that this phenomenon might be explained by supposing V. Lowei to be a wild hybrid, with the two sorts of flowers representing another example of the dissociation of parental types well documented in Cytisus Adami (see n. 15, below). On Vanda Lowei, see also the letter from J. D. Hooker, 20 August 1862 and n. 12.
10
CD had described an unnamed species of Mormodes, sent to him by James Veitch Jr, in Orchids, pp. 265–9. Veitch subsequently sent CD further flowers from the same plant, which CD described in notes dated 9 July 1862 (DAR 70: 103–4); these notes were headed ‘Cycnoches Ventricosum | named by Lindley’. See also letter to H. G. Bronn, 11 July 1862, and ‘Fertilization of orchids’, p. 155 (Collected papers 2: 151–2).
11
CD acknowledged receipt of a specimen of Cycnoches from the Royal Botanic Gardens, Kew, in the letter to J. D. Hooker, 6–7 October [1861] (Correspondence vol. 9). In his notes on C. ventricosum, dated 9 July 1862 (DAR 70: 103–4), CD described the observations that led him to conclude that the specimen he had received from Veitch (see n. 10, above) was hermaphroditic. He then noted: ‘See reference to Mr Bateman. C. Egertonianum must be male or female—’. The reference is to CD’s notes (DAR 70: 152) on Bateman [1843], recording that: Cycnoches Egertonianum … in Guatemala produced & once in England a scape dark purple & totally different species of Cycnoches, but generally in England scapes of the common Cycnoches ventricosum yellow & much larger— … It wd appear as if in this country it reverted to C. ventricosum. CD had originally noted: ‘C. ventricosum seeds itself, so not sexual distinction’, but in Orchids 2d ed., p. 224, he reported that he was inclined to believe, by analogy with Catasetum tridentatum (a synonym of C. macrocarpum, the jumping orchid), that the various forms were to be explained by the existence of ‘male, female, and hermaphrodite forms of the same species of Cycnoches.’
12
William Hugh Gower was a foreman at the Royal Botanic Gardens, Kew.
13
Oliver had sent CD a copy of Müller 1857 (see letter to Daniel Oliver, [before 11 June 1862] and n. 2, and letter to J. D. Hooker, 11 June [1862]).
14
CD probably refers to the bird’s-eye primrose, Primula farinosa; having failed to supply CD with specimens of this species during the previous season (see Correspondence vol. 9), Oliver had expressed a hope in April 1862 that he would be able to do so in the coming season, and had promised to write to let CD know (see letters from Daniel Oliver, 10 April 1862 and 14 April 1862; see also letter to Daniel Oliver, 12 [April 1862]). P. farinosa flowers in Britain in June and July (Lindley 1859, p. 184).
15
CD had for many years been interested in the origin of the hybrid laburnum, Cytisus Adami, branches of which had reportedly been found to bear the leaves and flowers of both the parent species (C. purpureus, a synonym of Chamaecytisus purpureus, purple broom, and C. laburnum, a synonym of Laburnum anagyroides, common laburnum) in addition to those of the hybrid form (see Correspondence vols. 4–6). In Variation 1: 387–97, CD discussed at length the evidence for and against the different theories that had been advanced to account for the hybrid form, dwelling particularly on the possibility that it was either an ordinary hybrid, formed by seed, or that it was what he called a ‘graft-hybrid’. In regard to the former he noted that he had ‘tried in vain to cross C. laburnum and purpureus’ (p. 389), continuing: ‘when I fertilised the former with pollen of the latter, I had the nearest approach to success, for pods were formed, but in sixteen days after the withering of the flowers they fell off.’
16
[Oliver] 1862c. At the end of his review of ‘Dimorphic condition in Primula’ in the Natural History Review, Oliver expressed his hope to be able to discuss dimorphism in the Orchidaceae ‘in connection with Mr. Darwin’s new work on the ’Fertilisation of Orchidaceae‘ in a future number.’ In the event, Joseph Dalton Hooker wrote the review of Orchids for the Natural History Review (see letter from J. D. Hooker, 7 November 1862).

Please cite as “DCP-LETT-3664,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-3664