RECORD: Darwin, C. R. [1878.07.10-12]. Erytherina caffra. CUL-DAR209.2.34. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 5.2023. 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-DAR209.2 contains materials on circumnutation of leaves and stems for Darwin's book Movement in plants (1880).


[34]

Erythrina caffra

A plant 18 inches high with fine young leaves.— one 7 1/8 inches in length with petiole, & with terminal leaflet by itself 2 3/8 in length, its apex being 9 1/4 inches from vertical glass, under skylight— Glass filament affixed two any under g transversely across extreme [sketch] tip of terminal leaflet— Advantages & disadvantage of this method explained under Amphicarpæa. Stem secured at base of petiole— (Temp. on 10th & 11th between 17 1/2 & 18 1/2 C.—)

It was remarkable that owing to shaking or being kept for a previous previous day under dim light of skylight, the terminal leaflet hung down all day (Jun 10th) down vertically as when asleep; but it still circumnutated, as may be seen, making at least what represent 2 ellipses: during the night it moved back toward the stem.

Next day (11th) circumnutated still more plainly, making almost 4 irregular ellipses, & by 3° P.m the leaf stood horizontally: by 7° 15' P.m was asleep or hung down vertically, & still more completely so by 8° 8. P.m. but continued to move first in one direction; then in another between 7° 15' & 11° P.m. & continued had moving moved considerably by 7° 40' a.m next morning

N. B. The leaf was in such a position that when it rose it tracing moved up & to left— when it fell tracing fell & moved to right


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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 24 July, 2023