The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. 1879.05.03. Beans. CUL-DAR209.5.72. 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-DAR209.5 contains materials for Darwin's book Movement in plants (1880).

[72]

May 3d /79/ F showed me 4 radicles of Beans, growing perpendicularly down in water & exposed to light, & 4 whose tips had been touched with caustic, & these 4 had radicles immensely bent to Sachs' curvature— now cause of straight, downward curve is due to geotropism, this is destroyed by sensitive apex being injured & these innate causes, not confined to apex come into play, & Sach-curvature strongly pronounced— So Black gum on apex, caused lateral curvature. Try at least 8 more with & without caustic

(over)

[72v]

Neither cauterizing tip, nor cutting them off interferes with "Sachs' curvature"

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