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Darwin Correspondence Project

To Lawson Tait   20 July [1875]1

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

July 20th

My dear Sir

I despatched of course your article.—2 I read it rather hurriedly to catch morning post. I will read it deliberately when published.— If you have succeeded in separating the ferment the fact is manifestly most important.3 Did you try whether the fluid from pitchers with no animal matter could digest? This, I think, ought to have been done to prove that there was ferment in the fluid.4 Glad to hear about the passage for guiding insects, as I speculated & told Hooker I guessed that this was the case.—5

Yours sincerely | Ch. Darwin


The year is established by the reference to Tait’s note in Nature (see n. 2, below).
Tait had sent a note on insectivorous plants with his letter to CD of 19 July [1875]; it appeared in Nature, 29 July 1875, pp. 251–2.
Tait claimed to have separated a substance closely resembling pepsin from the secretions of Drosera dichotoma (now D. binata, forked-leaf sundew) and various tropical pitcher-plants (Nepenthes). See letter from Lawson Tait, 15 July [1875] and n. 5.
CD had given this advice in his letter to Lawson Tait, 17 [July 1875].
Tait described a channel on the back of the pitcher in Nepenthes that served as a guide for insects to enter the fluid-filled reservoir (Nature, 29 July 1875, p. 252). Joseph Dalton Hooker was working on the digestive properties of Nepenthes (Correspondence vol. 21).


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


CD returns MS of a paper by RLT. "If you have succeeded in separating the ferment, the fact is manifestly important." Asks whether RLT tested the digestive ability of fluid from pitchers without animal matter. This would be necessary to prove that there was ferment in the fluid. CD is glad to hear about the [passage?] for guiding insects; he had guessed this to be the case.

Letter details

Letter no.
Charles Robert Darwin
Robert Lawson (Lawson) Tait
Sent from
Source of text
DAR 221.5: 28
Physical description
2pp (Photocopy)

Please cite as

Darwin Correspondence Project, “Letter no. 10080,” accessed on 4 March 2021,

Also published in The Correspondence of Charles Darwin, vol. 23