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Darwin Correspondence Project

From John Scott   16 May [1864]1


May 16th.


I am glad to find by your note of the 8th.2 that you are interested with my paper and have thought it worth communicating to the Linn. Soc.3 The knowledge that the importance of such subject is not as yet generally recognised does not at all dishearten me: were I again in a position for following out such I would avail myself of it with increased interest.

I am surprised to hear that your seedlings of non-dimorphic cowslip present similar characteristics. I had thought from the extreme rarity of such forms, that inheritance would be an exceptional occurrence. It will be a most interesting note for my paper on Primulas.4 I have not yet had proofs. I thought the “Journal” had been issued quarterly!5

The seeds sent of the red Primrose are the produce of long-styled homomorphic unions.6

From the inveterate sterility (i.e. so far as my experience goes) of unions between the red & common yellow primroses, I had an idea that the former would truly reproduce itself from seed: prove at least a perfectly established variety. I am surprised to find that this is not the case: but that seedlings revert to wild form.7 The fact, however, of reversion gives an increased value to my observations on sterility of crosses. I unfortunately cannot—as I would have liked—continue experiments for this season at least, as I have not a single red primrose in our garden, & I had no thought when I came of being here so long, otherwise I would have brought some from Edinburgh with me.8

It occurs to me from difference in results of crosses between white and yellow; and yellow and red primroses and from similar though less marked relations being manifested between the differently coloured varieties of Verbascums (e.g. V. phœniceum yield more seed with the variety roseum than with album, and so with the reciprocal crosses of these) that the sterility thereby induced is definitely related and finds an exponent in colour nomenclature.9 Thus we may suppose that a greater change must take place in the minute anatomy of a purple flower to give the impression of whiteness than that of redness (as in above Verbascum cases—and so in red, yellow, and white primroses) and that consequently the degree of sterility of unions between differently coloured varieties of a species may be inversely proportionate to their colour affinities.

Might I remark on this in giving Verbascum experiments??10

The smallness of flowers sent of equal-styled primrose was due to their being produced in a close-room. Those flowers borne upon the plant when I found it in the neighbouring woods were much larger. I have carefully examined it however, & have no doubts as to its being other than pure primrose.

I can only again express my sincere thanks for your continued offers to assist me:11 would that my hopes were at all sufficient to permit of my availing myself of your generosity; but it is otherwise & I can only look into life’s future with a strange presentiment— — I have not one here to whom I can look for assistance in the getting a situation.

I remain | Sir | Yours respectfully & obliged | J. Scott.

CD annotations

2.4 I thought … quarterly! 2.5] scored pencil
3.1 seeds … unions. 3.2] scored pencil


The year is established by the relationship between this letter and the letter to Richard Kippist, 6 May [1864].
CD’s letter has not been found.
Scott refers to the manuscript of his paper ‘On the individual sterility and cross-impregnation of certain species of Oncidium’ (Scott 1864b; see letter to Richard Kippist, 6 May [1864] and n. 1).
Scott discussed a non-dimorphic red variety of cowslip (Primula veris) in Scott 1864a, pp. 105–8, but did not mention CD’s seedlings; presumably this was because of CD’s modified statement about them in his letter to Scott of 20 May [1864]. For William’s sketches of the pollen of the non-dimorphic red cowslip, see memorandums from W. E. Darwin, [30 April 1864] and [after 19 May 1864]. See also letter to W. E. Darwin, [14–17 May 1864] and n. 2. CD’s notes on non-dimorphic red cowslips, which he raised from self-pollinated seed sent by Scott, are in DAR 108, including a summary of crossing experiments made in 1864 with observations on inheritance (see DAR 108: 120). CD published his observations in ‘Illegitimate offspring of dimorphic and trimorphic plants’, pp. 426–30, and Forms of flowers, pp. 234–8.
The Journal of the Linnean Society (Botany) was published in parts, the dates of publication varying from year to year; in 1864 parts were issued in April and September (General index to the Journal of the Linnean Society, p. vi).
Scott had sent CD seeds of a red variety of primrose (Primula vulgaris var. rubra) with his letter of [26 July – 2 August 1863] (Correspondence vol. 11). Scott had performed a number of crossing experiments with this variety and a white variety of primrose (see Scott 1864a, pp. 97–103).
CD discussed Scott’s experiments (Scott 1864a, p. 98) with the red variety of primrose and the common primrose, a case of apparent intra-specific sterility, in Variation 2: 109 n., and in ‘Illegitimate offspring of dimorphic and trimorphic plants’, p. 420. CD repeated the experiments with Primula vulgaris var. rubra in 1865 and 1866 using the seeds sent by Scott, but was unable to confirm Scott’s observations. CD’s notes on these experiments are in DAR 108: 89b–98 and DAR 110: A2–4. See also Forms of flowers, pp. 224–8.
Scott had been employed at the Royal Botanic Garden, Edinburgh, until March 1864 (see letter from John Scott, 10 March 1864).
At CD’s suggestion, Scott had embarked on a series of crossing experiments with Verbascum in 1863 (see letter from John Scott, 7 January [1864] and nn. 17 and 18). Scott’s experiments with differently coloured varieties of Verbascum were summarised by CD in Variation 2: 106–7, using information that Scott sent him in January 1865 (see Correspondence vol. 13, letter from John Scott, 20 January 1865). Scott later published his results in Scott 1867. For a discussion of the significance of these experiments, see letter to John Scott, 20 May [1864] and n. 5.
Scott discussed his hypothesis respecting the relationship between colour affinities and degrees of sterility in Verbascum crosses in Scott 1867, pp. 164–72.
See letter from John Scott, 5 May [1864] and n. 9.


Thanks for communicating Oncidium sterility paper [see 4485] to Linnean Society.

Surprised that CD’s seedlings of non-dimorphic cowslip breed true.

Surprised also that the red primrose he sent reverts to wild form. He had reasoned from red’s infertility with yellow that it was an established variety. Tries to correlate inheritance of colour and sterility between varieties.

Letter details

Letter no.
Scott, John
Darwin, C. R.
Sent from
Source of text
DAR 177: 106
Physical description
4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 4498,” accessed on 18 January 2017,