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Darwin Correspondence Project

From Asa Gray   [2 June 1862]1

Long-styled Houstonia has shorter, stouter, & far more hispid stigmas—smaller anthers, & smaller pollen than short styled,—evidently a step towards the separation of the sexes.2

I am kept very hard at work all this month in College, &c— But after 6th. July, I can do something.3

Viola (V. cucullata, & V. lanceolata) is very pretty for cross-fertilizing.

Ever Yours | A. Gray

Do I bore you, with these scattering notes?

I jot things down here—keeping no other records, & send them off to you.

I enclose some flower-buds of Arethusa—.4 You can soak them.

CD annotations

2.1 I am … to you. 6.1] crossed red crayon
4.1 Ever … Gray] ‘June 2d 62’ added in margin, ink; circled ink
5.1 Do I … them. 7.1] crossed ink


Dated by CD’s annotation.
While preparing his paper, ‘Dimorphic condition in Primula, CD had asked Gray for information on analogous cases (see Correspondence vol. 9, letter to Asa Gray, 16 September [1861]). In response, Gray mentioned, among other things, dimorphism in Houstonia, stating his intention to observe the differences in the pollen of the two forms the following spring, and his unsuccessful attempts to procure seedlings of H. carerulea to send to CD (see Correspondence vol. 9, letters from Asa Gray, 11 October 1861 and 9 November 1861). In addition, Gray had encouraged his pupil, Joseph Trimble Rothrock, to carry out further observations and crossing experiments on the two forms (see letters from Asa Gray, 2–3 July 1862 and 4 August 1862). CD mentioned the possibility that dimorphism might in some cases represent a stage in the development of dioeciousness in ‘Dimorphic condition in Primula, p. 95 (Collected papers 2: 62).
Gray was Fisher Professor of natural history at Harvard University and lectured at the Lawrence Scientific School (Dupree 1959).
In July 1861, Gray had recommended this orchid genus (or any other member of the Arethuseae) to CD’s attention (see Correspondence vol. 9, letter to J. D. Hooker, 17 [July 1861]). However, although CD made repeated requests for specimens from his botanical correspondents (see Correspondence vol. 9, and this volume), he was unable to see any ‘living flowers’ of the Arethuseae before the publication of his study (see Orchids, pp. 269–70).


Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

‘Dimorphic condition in Primula’: On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations. By Charles Darwin. [Read 21 November 1861.] Journal of the Proceedings of the Linnean Society (Botany) 6 (1862): 77–96. [Collected papers 2: 45–63.]

Dupree, Anderson Hunter. 1959. Asa Gray, 1810–1888. Cambridge, Mass.: Belknap Press of Harvard University.

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.


Discusses heterostyly in Houstonia.

Letter details

Letter no.
Asa Gray
Charles Robert Darwin
Sent from
Source of text
DAR 110 (ser. 2): 66
Physical description
ALS 1p inc †

Please cite as

Darwin Correspondence Project, “Letter no. 3588,” accessed on 3 February 2023,

Also published in The Correspondence of Charles Darwin, vol. 10