RECORD: Darwin, C. R. [1879?].10.18-21. Oxalis corniculata. CUL-DAR209.9.49. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 7.2022. 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 volume CUL-DAR209.9 contains materials for Darwin's book Movement in plants (1880).


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Oxalis corniculata

(I think of no use)

A seedling about 48° old had filament affixed to one cotyledon, with the hypocotyl secured & its movement traced on a vertical glass, being feebly illuminated only from above. During the first day (Oct 18th), it moved from 8° 15' a.m downwards with two little rises in the course of the day; but in the evening it travelled to one side, owing apparently to the bowing & twisting of the growing hypocotyl. Next day 19th See Fr the hypocotyl was readjusted & now from 7° a.m to about 1° it again moved downwards afterwards upwards, in a zig-zag course till 6° P.m, when it fell, at first slightly & then greatly till 9° 40' after which it rose till 10° 30'.— During night moved to one side, & next morning from 6° 45' a.m. to 10° 15' rose, then fell slightly & afterwards greatly till 5° 45' after which rose till 10° 40' P.m. During the night & next morning till 8° a.m fell.

[in margin:] This wd be sufficient But it must be ascertained— whether everything false for want of illuminations False for want of illumination

From these observations it is evident that the cotyledon of this species, whilst from 2 to 5 days old circumnutate in a simple manner, & that the periods of circumnutation are not regulated by the alternation of day & night; ?? for on 2 evening did not rise till latest at night, & on one morning rose & on 2 other fell in the early morning. Moreover it shd →

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be especially observed that 2 seedlings of the above ages had not their cotyledons raised to angle of about 45° as occurs with older seedlings every night. Can structure & movements be a vestige of former condition when species slept well — I think not for if so then structure & movement wd have been best marked during the few first days of life. — More like incipient structure. But I do not positively know that they do not rise when very young if sufficiently illuminated.

Frank has described structure of the petiole at successive periods.—

I think that I traced movement of first day??

N. B This not rising at night may be due to insufficient illumination.—

N. B. Make statement about O. floribunda Cots. going to sleep by depression

Oxalis


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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 25 September, 2022