skip to content

Darwin Correspondence Project

To Charles William Crocker   31 January [1864]1

Down. | Bromley. | Kent. S.E.

Jan. 31st

My dear Sir

Last summer you gave me hopes that you would give me information with respect to your observations on Hollyhocks.2 Will you forgive me for reminding you, that I shd. be very glad to hear the result of any of your experiments.—

I very much wish I could persuade you to try some experiments on the relative fertility, or number of seed, of some crosses between the most distinct varieties.—3 I have always wished & intended to try this myself, but I have so many “irons in the fire” that I know not when I shall have the time.—

Pray excuse me for venturing to trouble you & believe me Dear Sir | Yours very faithfully | Charles Darwin


The year is established by the relationship between this letter and the letter from C. W. Crocker, 1[–4] May 1863 (Correspondence vol. 11) (see n. 2, below).
CD refers to the letter from C. W. Crocker, 1[–4] May 1863 (Correspondence vol. 11). In his letters to C. W. Crocker of 18 May [1861] and 1 June [1861] (Correspondence vol. 9), CD detailed his interest in hollyhocks. See also Correspondence vol. 10, letters from C. W. Crocker, [before 13 March 1862] and 17 May 1862.
CD had long been keen to determine the relative fertility of different crosses of hollyhocks, and wondered why varieties often bred true even when growing next to each other (see Correspondence vol. 5, letter to J. S. Henslow, 12 November 1855; Correspondence vol. 9, letter to Journal of Horticulture, [before 14 May 1861], letter to C. W. Crocker, 18 May [1861], and letter to C. W. Crocker, 1 June [1861]; and Correspondence vol. 11, letter to Charles Turner, [1 April – 16 June 1863?] and n. 3). See also DAR 157a: 1, for CD’s notes on hollyhock experiments; Natural selection, pp. 65, 71; and Origin, p. 271. CD discussed the crossing of hollyhocks in Variation 2: 107–8.


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

Natural selection: Charles Darwin’s Natural selection: being the second part of his big species book written from 1856 to 1858. Edited by R. C. Stauffer. Cambridge: Cambridge University Press. 1975.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

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


Reminds CWC that he offered to give information with respect to his observations on hollyhocks. Wishes he could persuade CWC to undertake experiments on the fertility of some crosses between the most distinct varieties.

Letter details

Letter no.
Charles Robert Darwin
Charles William Crocker
Sent from
Source of text
Cleveland Health Sciences Library (Robert M. Stecher collection: FF8)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 3425,” accessed on 15 April 2021,

Also published in The Correspondence of Charles Darwin, vol. 12