To W. T. Thiselton-Dyer   14 May 1878

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

May 14th. 1878

My dear Dyer.

I am particularly obliged for your letter, though I can assure you that I had no intention whatever of asking you to write.—1 What you say about Heliotropism is very satisfactory to me, & very different from the impression which I received (perhaps falsely) from the Report.2 It shows how Heliotropism may have originated. I find that if respiration is stopped by thick layer of blackened greasy matter along one side of stem, the opposite side goes on growing & a curvature follows directed towards the blackened side like that from Heliotropism.— But I am sure that there is much yet to make out by Heliotropism.— One part of stem when shut off from light acts on or transmits an effect to other & distant parts.

I will soon return several plants to Kew, but must first observe one little point.

Do you care to have at Kew Drosera Whittakerii:3 it is finely in flower with me, & I do not want the plants? If you do wish for it, send me a Post-card: if I do not hear, I shall understand you do not want them.

Would it be possible to send me 2 or 3 corms of Colchicum autumnale; I want to see how flowers break through the soil.—4

I noticed hurriedly in Athenæum & hope to see further notice in “Nature”, that Mr Lynch has described some plant (name forgotten) which has one cotyledon rudimentary:5 I have lately been observing a strictly analogous case & there are 2 or 3 points which I shd like to see in Mr. Lynch’s plant,—if by any chance you have any seeds left; but I shd require to know what heat to subject them to.—

Ever yours very sincerely | Ch. Darwin

Lo & behold, I believe one of my Cycas seeds is trying to germinate!6

(Your letter to Frank has been forwarded | He returns on or about the 23d.)7

2
See letter to W. T. Thiselton-Dyer, 9 May [1878] and n. 7. In his letter of 11 May 1878, Thiselton-Dyer sought to correct the impression CD had after reading an article in The Times that he had argued that plants did not turn to light ‘for their profit’.
3
Drosera whittakerii (the name is an orthographic variant of D. whittakeri, scented sundew) is a native Australian species of sundew. Joseph Dalton Hooker had described a specimen borrowed from the Royal Botanic Gardens, Edinburgh, in Curtis’s Botanical Magazine 30 (1874): tab. 6121; he had then offered to lend it to CD (see Correspondence vol. 22, letter from J. D. Hooker, 22 July 1874). CD did not refer to this species in Insectivorous plants.
4
Colchicum autumnale is the autumn crocus, a member of the family Colchicaceae, and unrelated to true crocuses. Its leaves appear in spring and die back in summer, and flowers appear in autumn.
5
A report in the Athenaeum, 11 May 1878, p. 606, noted that Richard Irwin Lynch’s paper on the seed structure and germination of a species of Pachira was read before the Linnean Society on 2 May 1878 (Lynch 1878). Lynch described the germination of Pachira aquatica (Guiana-chestnut or provision tree), noting that one cotyledon or seed-leaf was large and fleshy while the second was reduced in size and not fleshy. The summary of the paper that appeared in Nature, 23 May 1878, p. 110, described the unequal cotyledons and the fact that the larger one persisted for six months while the smaller one seemed functionless.
6
CD had been trying to germinate seeds of Cycas, the only extant genus of the family Cycadaceae, a very ancient group of trees (see letter to W. T. Thiselton-Dyer, 9 May [1878] and n. 4).
7
Francis Darwin had taken his son, Bernard, to Pantlludw, Wales, to visit the family of his late wife, Amy Darwin; according to Emma Darwin’s diary (DAR 242), he returned to Down on 27 May 1878.

Manuscript Alterations and Comments

1.3 (perhaps falsely) 1.4] interl
1.5 blackened] interl
1.7 from] above del ‘of’
1.9 on] interl
1.9 & distant] interl
2.1 will] after del ‘wll’
3.2 if … them. 3.3] added
4.1 corms] above del ‘bulbs’
5.1 that] interl
5.2 has described] above del ‘on’
5.2 (name forgotten)] interl
5.3 strictly] interl
5.5 require] above del illeg

Please cite as “DCP-LETT-11508,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11508