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Darwin Correspondence Project

To John Scott   1 July 1876

Down, Beckenham.

July 1. 1876

My dear Sir,

I am much obliged to you for having sent me your two reports on the culture of the Poppy, & I have read them with much interest.1 Your observations seem very important and promising under a practical point of view; and I am glad to observe that you keep up that zeal which you have always showed. I have sown the seeds, from mere curiosity to see the plants; but from the spring being so cold I fear they will not do much good.2

I am now going to suggest a subject which if I had been a younger man I should certainly have investigated. No doubt you know that M. Jourdan splits up some of the species of Draba, Papaver, &c, each into more than a score of subspecies, and he asserts that they may be sown close together & never intercross, so that each keeps true to its kind by seed.3 Now if I understand rightly, the numerous vars of P. somniferum, which grow mingled in your fields, come true by seed with the exception of certain monstrous forms. How is this, and why do they not intercross, like the vars of cabbages carnations, &c in our gardens? I would suggest your castrating the unexpanded flowers of two or three vars, and by leaving them discover whether pollen is brought to them by insects. (What insects visit the flowers?). If they seed even to a moderate extent, I would then try the effects of mixing pollen of the same variety, but taken from a distinct plant (pray attend to this latter point,)4 with pollen from another variety, and then place the mixed pollen on the stigmas of the first variety without castrating the flowers. Sow the seeds and observe whether the seedlings are hybridised. If they are hybridised & yet you are able to raise pure vars from seed collected where many vars grow mingled together, then we should have evidence that forms which most botanists would certainly rank as mere varieties, are so far constituted like species, that they do not naturally intercross notwithstanding that pollen is carried from plant to plant by insects.

Wishing you all success in your valuable researches, & that you may keep your health, I remain | my dear Sir | Yours very faithfully | Charles Darwin

Footnotes

Scott was in charge of the experimental gardens at Deegah and Meetapore near Bankipore, India, and wrote annual reports on the cultivation of the opium poppy (Papaver somniferum) there. Scott had sent five copies each of the reports for the 1874 and 1875 growing seasons (Scott 1874 and 1876) to the Royal Botanic Gardens, Kew. In a letter to William Turner Thiselton-Dyer of 5 May 1876 (Directors’ Correspondence 156/1096; Royal Botanic Gardens, Kew), Scott requested that copies be sent to CD. CD’s annotated copies of the reports are in the Darwin Library–CUL.
In a letter to J. D. Hooker of 15 April 1876 (Directors’ Correspondence 156/1094–5; Royal Botanic Gardens, Kew), Scott enclosed two packages of seeds of opium poppies together with a list of the thirty-three different varieties he had sent. He asked that one package be forwarded to CD and an annotation on the letter records the package was sent to CD on 9 May 1876.
Alexis Jordan described twenty forms of Draba verna (a synonym of Erophila verna), classifying these as separate species with the genus name Erophila, in the first part of Icones ad floram Europæ novo fundamento instaurandam spectantes (Jordan and Fourreau 1866–1903). Jordan had argued that there was a group of poppies similar to Papaver dubium that ought to be classed as separate species because they bred true even when grown together for several years (Jordan 1860, pp. 467–8). In 1867, CD had experimented with seeds of some varieties sent to him from France; he recorded his results in Cross and self fertilisation, pp. 108–9 (see Correspondence vol. 15, letter to Edouard Bornet, 20 August [1867]).
In Variation 2: 131–44, CD had discussed self-sterility in plants and concluded that the condition had developed to promote crossing; he noted that a graduated series could be observed, from plants that were completely self-fertile to those whose own pollen was poisonous, and that self-sterility could develop under changed conditions. CD had found in experiments with Eschscholzia californica (California poppy) that plants fertilised with pollen from distinct plants produced significantly more seed than those that were self-fertilised (see Correspondence vol. 17, letter to Fritz Müller, 1 December [1869]).

Bibliography

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.

Jordan, Alexis. 1860. Diagnoses d’espèces nouvelles ou méconnues pour servir de matériaux à une flore de France réformée. Annales de la Société Linnéenne de Lyon 7: 373–518.

Scott, John. 1874. Report on the experimental culture of the opium poppy with observations on its drug-yielding properties, and the more prevalent and serious forms of disease and injury to which the plant is subject for the season ending 15th April 1874. Calcutta: Bengal Secretariat Press.

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

Summary

CD has read the two reports on culture of poppies with interest and has planted seeds.

Suggests an experiment for evidence on whether plants, thought merely varieties, are like species and fail to intercross, despite insect pollination.

Letter details

Letter no.
DCP-LETT-10555
From
Charles Robert Darwin
To
John Scott
Sent from
Down
Source of text
American Philosophical Society (Mss.B.D25.)
Physical description
4pp

Please cite as

Darwin Correspondence Project, “Letter no. 10555,” accessed on 20 February 2020, https://www.darwinproject.ac.uk/letter/DCP-LETT-10555.xml

Also published in The Correspondence of Charles Darwin, vol. 24

letter