RECORD: Darwin, C. R. [ny].10.19-21. Tomato (Solanum lycopersicum). CUL-DAR209.7.118. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 8.2022. 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 volumes CUL-DAR209.7-8 contain notes on heliotropism (phototropism) for Darwin's book Movement in plants (1880).
(2
Tomato
(Solanum lycopersicum)
(Used)
Oct 19th Secured stem & fastened bristle longitudinally to one cot. & then covered up pot in brown-paper cot. First dot at 9º 15' but by 1º no vestige of movement. Thus it is clear that without excitement of light, Cots. do not move.
(10º 30' P.m The younger plants now have leaflets almost closed.
(Oct. 20 I fastened bristles to 1 cot. on 2 plants & placed them facing light, the stems having been secured, but tops of stems grew rapidly & the 2 cots. bowed towards light & quite spoiled trial. The Cots. were also I think overpowered by weight of Bristles. All failed.)
Oct 21. In the morning the plantlets bent at ∠ to light in study. At 1º put them in window of dining room in reversed position & they were at 5º bent at right angle in opposite direction, so that they had moved during day through angle of 180º. +9º At night the Cots. did not go to sleep was this result of so much movement?
Light
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 29 August, 2025