RECORD: Darwin, C. R. [ny].08.12-30. Nelumbium esculentum. CUL-DAR68.131. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 4.2023. 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 volume CUL-DAR68 contains notes on 'bloom'. Francis Darwin explained: "His researches into the meaning of the 'bloom,' or waxy coating found on many leaves, was one of those inquiries which remained unfinished at the time of his death. He amassed a quantity of notes on the subject". LL3: 339. See an Introduction to these folders by Christine Chua & John van Wyhe.


[131]

Aug. 12th morning 9° Nelumbium esculentum

A str little stream of water at 90° makes a temporary cloud. — clean whole 1/2 leaf & fixed leaf so that water rest in middle alone on part of cleaned & uncleaned side.

Also cleaned 1/2 of 2 other leaves with cracked petioles & left dry marked with black wool. the side with Blue.

14th Augt (examined surface of leaf, covered with closely packed conical very minute points, which are projection of epidermic cells, but cd see no difference between surface washed with ether & not so. It is surprising how quickly Ether acts, I had bit of leaf with water under covering glass & put a few drops of ether to one corner & instantly silver margin disappeared & water adhered to the points. These must be some (a) on Back waxy varnish.

Alcohol & Oil of Cloves removes; but acetic acid no effect)

Aug. 15' 9° the half leaves black wool; I think a little yellowish on margin

Aug. 26 The leaf with water has several brown sparkles & a space where water lay yellowish: no difference in the halves of black-wool. —

Aug 30' do about black wool.

[131v]

((a) Aug 16.— I have been looking again & with 2d object-glass the tapering conical projections look slightly rough & more opake, (though I can see no distinct projections on them) & when washed with ether the conical projections have sharp outline & look more transparent. — With highest object glass, I can indistinctly see granules on the conical projections.)


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

File last updated 13 July, 2023