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Darwin Correspondence Project

From T. L. Marshall   16 July [1874]1

Derwent Island | Keswick.

July 16.

Dear Sir—

I have so much to say that I hope you will excuse my writing instead of or in addition to my father—2 We have only just come back here & the day being hot, waited so late for the 1. mile row—do. walk by the Pinguiculas, on wh we were bent. that we came in 12 hr. after post went—& 2 hrs. later I found all our nice specimens dry & pale—& sticking to the tin— I have floated them in water—but many corpses already float off! light & empty as they are   I counted 20 to 24 distinct remains of insects on many leaves— 1 live spider & one “hopper”3—a


shaped animal—of great vigor & restlessness, have given me most amusement, among the 12 caught. What makes them stay? for plainly the hopper cd. go—but he only crawls from one leaf or stalk to another. The spider is free—whether by our jolting stimulating his nervous energy, I cant guess— Thursday he is dead now.4 It was nice to watch him—greedily drinking off his trunk what I suppose comes off the leaf   Then he cleaned 1 fore ft. with the leathery tool— then sucked it again— then the other— His action, when he tried to walk, was like a very high stepping horse angry at the curb—I shd. say from the stickiness. But I want to know if it is sweet & opiate? as so many flower honeys are—& if he likes it. I hope he will be silly by morn—that I may see & I cannot else account for the [lazy] hopper.

A beetle was fresh enough to seem quite undigested to me—but he begins to look gummy—


One of those whose bodies & heads are this shape.


I want to know if azaleas5 & others wh are called fly catchers by gardeners—tho they never close—but stick flies to the outside of their flowers—till they die & evaporate? or are absorbed—have any motive in so disfiguring all their throats     Why shd. they not keep all the honey inside the same & not be sticky out, unless they too want animal food? I do not know what others have found out abt this—

Drosera6 is far more sticky from every drop, at end of every hair, than this Pinguicula— Have you any suspicion of those glaucous sort of mosses wh grow flat & sticky in damp places shady waterfalls etc—hairs roughly so—


I shall be glad to get anything you wd. care to see—& probably this is a good region. Its only a pity you dont come. I hope yr. son Horace is stronger than when he was here?7 I thought he might grow up strong enough—with judicious care, & cheerful bullying—mixed—

I counted 20 or 24 remains on various leaves, up to moths & active beetles—& good big spiders—& ants—(if our friend gets away—) The best were always in exposed places—on the edge of bank 4 ft. above road—not in marshy hollows— I suppose we saw 200 plants—in 12 mile stroll—

I hope they will recover & be posted when this goes—tomorrow— It is awfully nice for us (Father & me) to have anything to look out for—or that we can observe & we are very hard upon each others ideas—tho respecting each others facts sufficiently—not implicitly—so do set us some more, if you can—of anything I can observe

Have not yr Pinguiculas caught any flies, since they do so well?

I am not sure of any seeds,8 but think I found several—& ends of Free flowers stick there— I’m not sure of seed, 12 seeds & remains will be washed off but will gladly send another lot—if it wd. be of any use to you—or satisfaction.

Do you suppose the plant wants to eat the seeds? or that these survive its decay—& grow? I enclose one seed pod of its own— Grass seed I found fixed by position—if no suction had been there—

Please excuse so long & ill written a letter—

Old Sir G Airey has been in—full of Venus’ transit & his 9 stations—9

Hoping the leaves will arrive well & that you’ll give us further commissions

I am yrs. truly | Theodosia Marshall


CD annotations

1.1 I have … off! 1.6] crossed blue crayon
1.6 I counted … distinct] underl blue crayon
1.6 I counted … leaves— 1.7] double scored red crayon
1.11 dead now] underl blue crayon
3.1 I want … disfiguring 3.4] scored blue crayon
3.3 Why … this— 3.5] crossed blue crayon
4.1 Drosera … mixed— 4.7] crossed blue crayon
Top of second page] ‘2’ blue crayon underl blue crayon
Top of fourth page] ‘3’ blue crayon underl blue crayon


The year is established by the reference to observations on Pinguicula (butterwort); CD had recently begun to study the digestive ability of this genus for his work on Insectivorous plants, published in July 1875 (Freeman 1977; see letter to Asa Gray, 3 June [1874]).
No letters to or from Henry Cowper Marshall have been found in the Darwin Archive–CUL.
Hoppers are true bugs of the suborder Auchenorrhyncha, but were formerly classified in the now invalid order Homoptera.
In 1874, 16 July was a Thursday. ‘Thursday . . . now’ is interlined.
Azalea is the name given to smaller deciduous shrubs of the genus Rhododendron, many of which have hairy, sometimes sticky leaves.
Drosera is the genus of sundews; most of CD’s experimental work for Insectivorous plants was done on this genus.
Horace Darwin was a friend of Marshall’s brother, William Cecil Marshall. The two were students at Trinity College, Cambridge, at the same time (Freeman 1978). The dates of his visit to the Marshalls are unknown.
CD suspected that Pinguicula could digest seeds as well as animal matter (see letter to W. T. Thiselton-Dyer, 9 June 1874).
George Biddell Airy, the astronomer royal, was in charge of the British expeditions made to observe the transit of Venus at the Hawaiian Islands, Egypt, Rodriguez Island, Kerguelen Island, and New Zealand (for an account of the observations, see G. B. Airy ed. 1881). Leonard Darwin took part in the expedition to New Zealand (see letter to W. D. Fox, 11 May [1874] and n. 12).


Freeman, Richard Broke. 1977. The works of Charles Darwin: an annotated bibliographical handlist. 2d edition. Folkestone, Kent: William Dawson & Sons. Hamden, Conn.: Archon Books, Shoe String Press.

Freeman, Richard Broke. 1978. Charles Darwin: a companion. Folkestone, Kent: William Dawson & Sons. Hamden, Conn.: Archon Books, Shoe String Press.

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


She and her father have been counting insect remains on Pinguicula hairs.

Letter details

Letter no.
Theodosia Louisa Marshall
Charles Robert Darwin
Sent from
Source of text
DAR 58.1: 123–4, 127
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9551,” accessed on 19 January 2021,

Also published in The Correspondence of Charles Darwin, vol. 22