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Darwin Correspondence Project

To Asa Gray   3 January 1877

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

Jan 3. 1877

My dear Gray,

I have just received your letter of Dec 22nd. It is very good of you to be willing to send me such rare specimens; but I could not in any case think of accepting your offer on the mere chance of making out whether the plants are heterostyled.1 The chance moreover would be very small without better specimens, as with dead plants no evidence I think is sufficient except difference in size of pollen-grains. I have lately given Kew so much trouble that I have vowed I would give no more for some time; but hereafter I will find out whether they can spare me any of the plants in question.2

I am very glad of the notice about the black pigs: my faith in Wyman is so great that I have not been shaken by Wallace, who founds his speculation on a very feeble basis.3

With hearty thanks | Yours very sincerely | Ch. Darwin

P.S. | Whenever you write again, can you tell me whether Primula Mistassinica, Linum virginianum & Bootii are dimorphic?4

P.S. I fear that Rhamnus lanceolatus will prove only sub-dioious; but if it is truly heterostyled it will a real treasure as explaining structure of R. catharticus.5


In his letter of 22 December 1876 (Correspondence vol. 24), Gray had offered to send two flowers of Leucosmia burnettiana. Leucosmia burnettiana is a synonym of Phaleria disperma, a tropical plant in the daphne family (Thymelaeaceae).
CD had received specimens of heterostyled plants from both Joseph Dalton Hooker and George Bentham, together with information on dioecy and identification of some species (see, for example, Correspondence vol. 24, letter from J. D. Hooker, 8 December 1876, and letter to George Bentham, 12 December 1876). CD described heterostyled flowers of Leucosmia burnettiana, received from Hooker, in Forms of flowers, pp. 114–15.
Jeffries Wyman had informed CD that black pigs in Florida were able to withstand a toxin in paint root (Lachnanthes caroliniana, now known as Carolina redroot) that caused the hooves of other pigs to drop off (see Correspondence vol. 8, letter from Jeffries Wyman, [c. 15] September 1860). CD had added the information to Origin 3d ed., p. 12. Alfred Russel Wallace, in his address to the biological section of the meeting of the British Association for the Advancement of Science in September 1876, had mentioned CD’s account of the pigs, but suggested that black pigs avoided the poisonous root, while white pigs, who Wallace supposed had an inferior sense of smell, consumed it (A. R. Wallace 1876, p. 105).
Primula mistassinica is the bird’s-eye primrose. Linum virginianum is woodland flax; L. bootii (a synonym of L. sulcatum var. sulcatum) is grooved yellow flax.
Subdioecious species are those with male, female, or hermaphrodite individuals in natural populations. In Forms of flowers, pp. 295–6, CD described Rhamnus lanceolatus (a synonym of R. lanceolata, lanceleaf buckthorn) as heterostyled with two hermaphrodite forms that resembled the two male forms of R. catharticus (a synonym of R. cathartica, common buckthorn).


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

Origin 3d ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 3d edition, with additions and corrections. By Charles Darwin. London: John Murray. 1861.


Asks AG not to send his rare specimens [of Leucosmia].

Is glad of the notice about black pigs.

Has great faith in Jeffries Wyman;

thinks A. R. Wallace founds his speculation on a feeble basis.

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
Gray Herbarium of Harvard University (118)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10768,” accessed on 22 September 2021,