RECORD: Darwin, C. R. 1880.01.17. Epinasty brings leaves down into proper position. CUL-DAR209.7.140. Edited by John van Wyhe (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. "In his experiments, DE VRIES eliminated the influence of gravity (geotropy) and light (heliotropy) and so doing found a third agent which influences the curvature of plant parts; a natural tendency of one side of a plant organ to grow faster than the other side. If this growth was fastest at the ventral side, DE VRIES called it epinasty; if the reverse was true, hyponasty." Peter W. van der Pas. The correspondence of Hugo de Vries and Charles Darwin. Janus 57: 173-213, p. 176. (F2106)
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).
[140]
Jan 17 /80/ Epinasty brings leaves down into proper position & thus, we know is a modification of circumnutation. But the question is why do leaves when, the branch which bears them is placed in a different position or reversed rearrange themselves in a horizontal position with the upper surface upwards. This seems to me strong— as we know that leaves exposed to a lateral many again, bend towards as light bend so as to place themselves at right angle to it. light leaves illuminated on one side more than another bend toward the light.— Frank's view.
[140v]
[illeg] that leaves of plants in window Window or [illeg] against a wall arrange themselves so as to face the light—
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022