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Darwin Correspondence Project

To Asa Gray   8 August [1867]1

Down, Bromley, Kent,

August 8.

My dear Gray,—

I have been glad to see Mr. Canby’s interesting letter on Dionæa, and I thank you for sending it; but unfortunately the facts are not new to me.2 Several years ago I observed the secretion of the “gastric juices” and the close adhesion of the two sides of the leaf when a fly was caught. I keep my notes in such an odd fashion that it would take me some time to find them. I am almost sure I ascertained the acid reaction of the secretion and its antiseptic power, but I cannot remember whether in this, or in analogous cases, I found its subsequent reabsorption.3 This letter fires me up to complete and publish on Drosera, Dionæa, etc., but when I shall get time I know not. I am working like a slave to complete my book.4


The year is established by the relationship between this letter and the letter from Asa Gray to J. D. Hooker, [after 6 July 1867].
CD refers to a letter from William Marriott Canby to Asa Gray of 6 July 1867, in which Canby described his experiments with the insectivorous plant Dionaea (see enclosure to letter from Asa Gray to J. D. Hooker, [after 6 July 1867]).
See Insectivorous plants, p. 296. Most of CD’s extant notes on his experiments with insectivorous plants, dated between 1860 and 1875, are in DAR 54 to 61. Notes made in September 1861 on the application of various substances to the leaves of Dionaea are in DAR 54: 50–61. See also Correspondence vol. 8.
CD was working on the proof-sheets of Variation.


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

Insectivorous plants. By Charles Darwin. London: John Murray. 1875.


Thanks AG for sending W. M. Canby’s letter on Dionaea. Although already familiar with the facts concerning the secretions, the letter "fires me up to complete and publish on Drosera, Dionæa, etc."

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
J. L. Gray ed. 1893, 2: 557
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5602A,” accessed on 31 July 2021,

Also published in The Correspondence of Charles Darwin, vol. 15