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Darwin Correspondence Project

From Charles James Fox Bunbury   7 February 1856


February 7. 1856

My dear Darwin,

As I know you are much interested in the questions relating to varieties & species among plants as well as 〈an〉imals, I will mention to you a 〈c〉ase which has excited my curiosity a good deal. In the Journal of the Horticultural Society, a few years ago, (5th vol. p. 31 & 32,) Lindley described & figured what he believed to be a very extraordinary variety of Colletia spinosa (a South American shrub),1 said to have been raised from seed of that species in Lady Rolle’s garden in Devonshire.2 The deviation from the original type, as shortly as I can state it, is mainly this: that 〈    〉 spines, or spiny-pointed branches 〈in〉stead of being nearly cylindrical, are so excessively dilated vertically, as to form nearly right-angled triangles, with 〈    〉 base (along the branch) often equal to the perpendicular. And this is a real extension of the wood, not merely of the cellular substance.3 Now 〈the〉 curious thing is, that this same variety (if such it be) grows wild in South America. Lindley’s description & figure agree perfectly (tho’ he seems to have quite overlooked this,) with those which Sir W. Hooker gives, in the first volume of the Botanical Miscellany, of his Colletia cruciata,4 found by Dr Gillies on sand hills near Maldonado.5 I find in Mr Fox’s collection, several fine dried specimens of the same, gathered also at Maldonado.6

I wonder whether you met with it there? If the origin of this plant in cultivation from seeds of Colletia spinosa be really certain, it is a very curious case of a seminal variety having 〈    〉 the appearance of a distinct species, & occurring in the wild state as well as in cultivation but I confess the evidence as to its origin does not appear to me quite satisfactory.7 You probably have the means of referring to the Journal of the Hort. Soc.,—I wish you would tell me what you think.

I was told last summer that you were becoming a believer in the unlimited mutability of species,—almost to the extent of the “Vestiges of Creation.”8 I suspect this is not strictly correct. I should be very glad to hear any thing you may think fit to tell me about your researches into the laws of species, a subject on which I hope you will one day enlighten us very much; also I should like to know whether you have obtained any further results as to the germination of seeds ex〈pos〉ed to salt water.9 I am afraid I have not yet any remarkable facts to send you in reference to Cape plants. 10 I forget whether I mentioned Frankenia to you as one of those genera which have their headquarters in Europe, but which have some truly indigenous species at the Cape of Good Hope. One species indeed, Frankenia lævis, appears to be common to Europe & the Cape; whether it is found in any intermediate country I do not know; but there are one or two peculiar to the Cape, with a very strong likeness certainly to those of the northern hemisphere, but distinct, as specific distinctness is generally understood. Dianthus I think I mentioned to you before: it is an interesting case, because I believe the genus exists nowhere in the southern hemisphere except at the Cape, & the genus is a peculiarly natural & well-marked one. 11 We have a vast deal yet to learn with respect to the limits of species; the excessive differences in the views of different 〈na〉turalists on this point intro〈duces〉 c〈onf〉usion & uncertainty into 〈    〉 reasonings on the geogra〈phy of〉 plants & animals. When 〈    〉 that what according to Duval’s views are nearly 50 different species of Solanum,12 are considered by Bentham as all referable to the one Solanum nigrum; & that another botanist has made 12 species out of our common White Water-lily; it is rather bewildering. I am myself quite ready to believe that the range of variation of species may be greater than even the most cautious botanists at present allow for; but I should be slow to believe that it is unlimited.

Ever yours very sincerely | C J F Bunbury

CD annotations

crossed pencil
‘20’added brown crayon; ‘Bunbury’added pencil 13
crossed pencil
Top of first page: ‘1’brown crayon, del brown crayon; ‘3’brown crayon


Bunbury refers to Lindley 1850.
Louisa Barbara Rolle of Bicton House, Devonshire. Her gardener, James Barnes, provided John Lindley with an account of the Colletia (Lindley 1850, p. 29).
Lindley considered this a case of transmutation without parallel, which threw ‘greatest doubt upon the original distinction of numerous plants now admitted into books as species’ (Lindley 1850, p. 32).
[W. J. Hooker] 1830a, pp. 152–3.
John Gillies, a naval surgeon, had collected plants in South America.
Henry Stephen Fox was Bunbury’s uncle. He had collected plants while British minister in Buenos Aires and Rio de Janeiro, 1831–3. On his death in 1846, Bunbury inherited his herbarium (R. Desmond 1977).
Lindley’s informant, James Barnes (see n. 2, above), had not at first been certain that the plant had been raised from seed (Lindley 1850, p. 29).
CD had told Bunbury as early as November 1845 that he was ‘to some extent’ a transmutationist (see Correspondence vol. 3, letter from Charles Lyell, [after 2 August 1845], n. 5). Bunbury refers to the anonymous evolutionary work Vestiges of the natural history of creation ([Chambers] 1844).
CD was nearing the end of a series of experiments begun in 1855 to test the vitality of seeds after submersion in salt water. See letter to M. J. Berkeley, 29 February [1856], and n. 1.
CD had previously written to Bunbury requesting information on Cape Colony plants (Correspondence vol. 5, letter from C. J. F. Bunbury, 10 April 1855).
CD included this information in Natural selection, p. 552 n. 3: ‘Mr. Bunbury thinks that the genera Dianthus, Franklinia Statice are the most striking cases of northern genera having representative species at the Cape.’ ‘Franklinia’ was a mistake for ‘Frankenia’.
A reference to the French gardener known only as jardinier Duval. CD had read three of his works in July 1854 (see Correspondence vol. 4, Appendix IV, 128: 8). Bunbury’s particular reference is to Duval 1852, a treatise on the potato family. There is an extract from this work in the Darwin Library–CUL.
CD cut the letter into two pieces. These annotations were to label the portion placed in portfolio 20, which contained CD’s notes on the geographical distribution of plants. The ‘3’ on the remainder was used for notes on marked varieties.


Has heard CD is much interested in questions relating to varieties and species. Mentions a case of a seminal variety of Colletia spinosa, described by John Lindley, which appears identical with another wild species of Colletia from S. America. Hopes CD will one day "enlighten us very much" on "the laws of species". There are many different views on the limits of species; M. F. Dunal made 50 species of Solanum which George Bentham considers are all varieties of S. nigrum.

Letter details

Letter no.
Charles James Fox Bunbury (8th baronet)
Charles Robert Darwin
Sent from
Physical description
6pp damaged †

Please cite as

Darwin Correspondence Project, “Letter no. 1830,” accessed on 27 April 2017,

Also published in The Correspondence of Charles Darwin, vol. 6