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Darwin Correspondence Project

To Mary Treat   1 June 1876

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R. [Hopedene, Surrey.]

June 1st 76

My dear Madam

I have received your kind letter & the article which I have read with the greatest interest. It certainly appears from your excellent observations that the valve was sensitive, & I hope it may be so from homologising with Pinguicula; but I cannot understand why I could never with all my pains excite any movement. It is pretty clear I am quite wrong about the head acting like a wedge.—1 The indraught of the living larvæ is astonishing.— I do not at all understand the German account of the development of the utricles & I suspect that these Germans did not look to young enough utricles.2

I am not well & am staying away from my home for rest, so pray excuse brevity.3 Wishing you success of every kind in your admirable work

I remain | Dear Madam | Yours very faithfully | Ch. Darwin


Thanks MT for her article ["Is the valve of Utricularia sensitive?", Harper’s New Mon. Mag. 52 (1875): 382–7]. Does not understand why he failed to detect movement [in Utricularia], but it appears from her observations that the valve is sensitive.

Letter details

Letter no.
Charles Robert Darwin
Mary Lua Adelia (Mary) Treat
Sent from
Hopedene Down letterhead
Source of text
Amy Nagashima (private collection)
Physical description
3pp (photocopy)

Please cite as

Darwin Correspondence Project, “Letter no. 10523,” accessed on 18 November 2019,

Also published in The Correspondence of Charles Darwin, vol. 24