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From Charles and Francis Darwin to W. T. Thiselton-Dyer   18 February 1876

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

Feb 18. 76

My dear Dyer

Many thanks about Cinerarea: I had no idea it was a Senecio: whenever you see Mr Moore pray thank him for me.1

I will return the Pleroma in a few days by rail, and let you know by 12d card when it is dispatched.2 We have cut off the branches which straggled up to the roof, leaving some of the lower ones. By the way I have made out that pollen from the shorter stamens fertilises much fewer seeds than that from the longer stamens. Cecropia & the Acacia have arrived in good state but I am frightened at having the unique specimen of the latter.3 They are both in fine condition for Frank to investigate; and Cecropia abounds with the little eggs or pats of butter whichever they may be called.4

With respect to the glands on the leaves of the common laurel, the stipules of Vicia, the phyllodium of some acacias &c I believe they are simple excretory organs; and this seems to me probable considering that some leaves under certain climatic influences secrete a sweet juice without possessing any glands.5 Delpino argues that the glands serve in every case to attract ants as a protection; but I do not believe this & with our common laurel hive bees suck the secretion much oftener than ants.6 A German whose name I can’t recollect (Reinke) maintains that the points of all crenated leaves are furnished in the very early bud condition with glands which excrete.7

With very many thanks for all your kind assistance | Yours very sincerely | Ch. Darwin

PS I | I understood from Murie that he had nothing to do with the Edinburgh Courant, but he hinted about some botanist who thought himself very unfairly treated by not going on the Arctic expedn.8 | CD

PS II | Many thanks for the beautifully clear labels, & for the Stipa information9 | FD

LS

1
See letter from Charles and Francis Darwin to W. T. Thiselton-Dyer, 14 February [1876] and n. 2. Thiselton-Dyer sent CD a letter he received from Thomas Moore discussing the botanical name of florist’s cineraria (letter from Thomas Moore to W. T. Thiselton-Dyer, 15 February 1876). At this time, the plant was placed in the genus Senecio (ragworts and groundsels), although it had formerly been classified as Cineraria (a related genus that is now mostly restricted to South African species).
2
See letter from Charles and Francis Darwin to W. T. Thiselton-Dyer, 14 February [1876] and n. 3. Pleroma (a synonym of Tibouchina) is a neotropical plant genus of the family Melastomataceae.
3
See letter from Charles and Francis Darwin to W. T. Thiselton-Dyer, 14 February [1876] and n. 5. Acacia cornigera (bull-horn acacia) and Cecropia peltata (the embauba or trumpet-tree) were the species sent.
4
Francis Darwin wanted to analyse the nutrient composition of the food bodies produced by Cecropia peltata and Acacia cornigera (see letter from Charles and Francis Darwin to W. T. Thiselton-Dyer, 14 February [1876] and n. 4). The ‘little eggs or pats of butter’ are now called Müllerian bodies.
5
The common laurel is Prunus laurocerasus. Vicia is the genus of vetch. The phyllodium (now more commonly referred to as the phyllode) is an expanded, usually flattened petiole resembling and functioning as a leaf-blade, the true leaf-blade being absent or much reduced in size (OED).
6
Federico Delpino had argued in ‘Rapporti tra insetti i tra nettarii estranuziali in alcune piante’ (Relations between insects and extranuptual nectaries in some plants; Delpino 1875, pp. 76–7) that extrafloral (or extanuptual) nectaries were only associated with ants or wasps.
7
Johannes Reinke had made the observation in ‘Ueber die Function der Blattzähne und die morphologische Werthigkeit einiger Laubblatt-Nectarien’ (On the function of leaf teeth and the morphological significance of foliage leaf nectaries; Reinke 1873, pp. 824–5). CD added a reference to Reinke’s observation in Cross and self fertilisation, p. 403 n.
8
James Murie had visited CD in December 1875, and may have commented on an article in the Edinburgh Evening Courant, but it has not been identified (Correspondence vol. 23, letter to W. T. Thiselton-Dyer, [19 December 1875]). The Arctic expedition of 1875–6 was led by George Strong Nares; two naturalists were employed, Henry Wemyss Feilden, an army officer and naturalist who served on HMS Alert, and Henry Chichester Hart, a botanist who served on HMS Discovery (Nares 1878, 1: ix–x). The botanist mentioned has not been identified.

Please cite as “DCP-LETT-10402,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10402