RECORD: Darwin, C. R. [1874?].09.19-27. U. montana. CUL-DAR59.1.131-134. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2022. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volumes CUL-DAR 54-61 contain material for Darwin's book Insectivorous plants (1875).

Utricularia is a genus of carnivorous plants known as bladderworts. These notes are for Darwin, C. R. 1875. Insectivorous plants. London: John Murray. (F1217)

"The social breadth of the network that Darwin drew on in his work on insectivorous plants was remarkable. The aristocratic horticulturist Dorothy Nevill hugely admired Darwin and was always eager to help by sending specimens from her well-stocked garden. ...[She] supplied Darwin with a specimen of Utricularia montana to work on. At first, Darwin mistook the empty stem tubers for bladders; when he found that the real bladders, which were very small and transparent and on the roots, captured prey, he exclaimed: 'I have hardly ever enjoyed a day more in my life than this day's work' (letter to D. F. Nevill, 18 September [1874]). Francis's new wife, Amy, drew the plant (letter to Francis Darwin, [17 September 1874])…Utricularia montana is an epiphytic species of bladderwort, native to the Antilles and northern South America. [It] is a synonym of U. alpina." Correspondence vol. 22, pp. xxviii, 447.


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U. montana.

The overarching base of antennæ & antennæ & their close proximity to footstalk makes a perfect roof to depression leading to opening excellent adaptation —

(The bisected tuber from which slice made gives out a Tuber little branch on one side bearing a bladder.)) (see Back)

Sept 19th Stomata on lower surface of ordinary Leaves a few papillæ on upper surface & a few papillæ, enlarged on upper surface — Broader than those on rhizomes

Glands extremely brown & granular

3d Another bladder with a decayed organism, which must have been spinose. — quadrifids not much affected, except that nuclei of different size & some very large nuclei & some with 2 spheres.

4' Another bladder with certainly an organism for I saw the hook at end of limb did not examine quadrifids bit not much affected.

[7v]

One Tuber on surface was greenish, (The development seen as in U. vulgaris.)

8

Proportion of Bladder with prey very small in this country, wd get more when bladders inserted amid decaying bark & moss & the rubbish which thickly covers Tropical Trees.

Another bladder on a Branch 1 1/2 inch deep

(5th Had decayed ani apparently animal matter & the quadrifids with numerous spheres of matter.)

Besides 2 lateral orifices the pit formed by valve & rim, there is a narrow one between the antennæ: the part supporting antennæ is not bowed, but then bow immediately & so much & one so close, that they protect the pit— good adaptation. Antenna sometimes lie even down or over & along valves surface

This little bladder (besides several tubers) must have born many hundreds perhaps some thousand true bladders, for a short branch had 32, & a branch about 2 inches long, carelessly removed with end & some side branchlets lost, bore 73 bladders, & the soil seemed filled with rhizomes as they must be from Homology of bladders

[8v]

Sept 24. Examined thin slice of Tuber wh which had been in alcohol for several days— only the minutest atoms deposited in walls— More large granules in rhizome & bladders—

Tuber can hardly serve as reservoir for food — The papillæ outside tubers have utricular lining contracted.

(The vessels are not true spirals, for the line is not continuous all round —)

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Sept. 26th Peristoma posteriorly semi-circularsp valve with about 12 transversely much elongated glands, on borders with very short footstalks — With Hartnack 8. tuber drawn out length of division of micrometer.

Spec had been kept for 24 in sol. of Urea (1 gr to 1 oz) — These trichome now continued generally towards centre several spheres of very translucent matter with tinge of yellow — there was in many from 6 to 8 of these spheres, & these ca very slowly changed position & forms & sometimes disappeared — Partly adapted for absorption from oozing out of water from bladders— The cavity in which valve lies very deep.

The bladder had been punctured, & quadrifids & bifids much affected — There were some with utricular layer, much shrunk, but I think these had been injured by the puncture. But in spines which had

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not u. Layer much or at all shrunk, these were in some 2 large balls of yellow translucent matter —

In many others there were all sorts of gradation between 2 balls more or less united, as if coalescing — some balls with merely a trace of a projection — In others there were odd shapes specks specks of same on utricular layer— many of these very odd shapes [sketches]

It is an evident that matter had been formed within & hardly coalesced — in some into many single large ball.—

This matter seems to aggregate round nucleus, or into independent balls. — I could see no change of form in these odd-shaped mass as long as I watched them.

Some nuclei had become granular & quite irregular in shape — Bifids similarly affected.

[10v]

The papillæ apparently also affected — Brown granular matter at bases — I observed chiefly those on petioles of bladders. — The papilla in water specn. also granular. —

I believe the Transverse glands are as big as in U. vulgaris

Sept 27' Kew spec. in one bladder apparently a [illeg] not digested & a linear organism utterly digested. Here much of the quadrifids with 2 spherical masses instead of one. — also insects grain of quartz in bladders—

6th


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

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