RECORD: Darwin, C. R. & Francis Darwin. [1877?].09.19 Mimosa. CUL-DAR209.2.113-117. 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-DAR209.2 contains materials on circumnutation of leaves and stems for Darwin's book Movement in plants (1880).
[113]
Sep 19
Mimosa angle between 2r.y petioles
From 12.23 pm to 4.14 pm the angle between the lea petioles changes from 61° [-] 54 [=] 7° to 54°; during this interval 3 of 3hrs 51 m ten observations were made which show that the angle sometimes diminishes & then increases again & so on.
The 10 observations are [data not transcribed]
From 4.14 to 6.45 the angle diminished & at 6.45 it was only 2°; this diminution was apparently steady as the angle was always smaller & smaller & never got big again {except once when it increased by 2° which may be an observation error}
The observations were not so more numerous in the evening as by 10 10 being made from 4.25 to 6.45 ie in 2 hrs 20mn
Temperature 20° to 23°C
On the following day observations f not so frequent but the angle was certainly more constant which may have to do with slightly lower temperature
[calculations not transcribed]
[114]
Nutation of primary petiole
Mimosa pudica No 1 Sep 28
Grass stalk which is the index projecting 75mm beyond fork of 2ndy petioles; looking & points to the main light – vertical glass – Sun & clouds – Thermometer hung close by. No fixing wanted to plant decimals of estimated old 110.0
[data not transcribed]
From glass to joint of Mim 125 mm about main petiole
[114v]
S
S 19
M 20
TU 21
W – 22
Th 3
F 4
S 5
[115]
Dr H Sep 28 Mimosa
[data not transcribed]
[116]
Mimosa Hot case (2) Sep 28 grass quite square to glass leaflets shut but not so the 2ndy petioles
[data not transcribed]
[117]
Mimosa ‒ main petiole (traced by foreshortening a grass index, on vertical glass
Hot case No 3, I found the leaf weight down & cut off some of the grass & moved plant nearer light glass. Fork of 2ndy petioles to tip of grass = 92mm
Joint of movement of main petl to ditto 150
Joint to fork ie (real moving arm) 58
Joint to glass when petiole Horizontal 226
when horizontal it multiplies 226 [÷] 58 times; about 4 times
[data not transcribed]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 24 July, 2023