RECORD: Darwin, C. R. n.d. Abstract of Pfeffer, Die Periodischen Bewegungen der Blattorgane. CUL-DAR209.7.154. 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. 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).
[154]
Pfeffer shows that the half of a joint pulvinus which is which is exposed to a strong light expands less quickly than the other & & less exposed half. * (*Pfeffer, Die Die Period. Bewegungen &c p. 7, 123 &c.)
[Movement in plants, p. 485: "But Pfeffer has shown that a difference in the turgescence on the two sides of a pulvinus,—that is, an aggregate of small cells which have ceased to grow at an early age,—is excited by a difference in the amount of light received by the two sides; and that movement is thus caused without being followed by increased growth on the more turgescent side.† † 'Die Periodischen Bewegungen der Blattorgane,' 1875, pp. 7, 63, 123, etc."]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022