RECORD: Darwin, C. R. 1877.10.29. Oxalis acetosella. CUL-DAR209.14.75. Edited by John van Wyhe (Darwin Online,

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 7.2023. 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-DAR209.14 contains material for Darwin's book Movement in plants (1880).


Oct. 29' 1877

Oxalis acetosella observed at night

(Plant had been Kept in pot in greenhouse)

Secured petioles of 2 nice youngis[h] leaves, close under leaflets to little sticks; with long bristles affixed longitudinally to central leaflets & marked a mark behind, traced on vertical glass.—

Diagram A shows that lea this leaflet after going to sleep moved a little laterally from side to side between 7° & 10° 40' P.m, going thrice in one direction & twice in nearly opposite one; after 9° 32 the leaflet rose a little: it did not do not become so closely inflicted as is natural during sleep, owing to interference of stick to which the top of petiole was tied, as was also shown next morning 6° 50' a.m for though though the leaf with bristle became horizontal & awake the lateral leaflets were not able fully to do so.

Diagram B. shows movement of leaflet viewed laterally, so that only the movement of leaflet toward petiole cd be shown; until 8°. 50' it continued moving to go more asleep; it appears, however, that leaflet began to rise rose a little towards end of observation & then fell again.

We may conclude that it nutates the leaflets nutate during early part of night. Quite awake at 6° 50' next morning. —

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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (

File last updated 17 August, 2023