RECORD: Darwin, C. R. [1878?].12.27-[1879?].01.02. Asparagus Seedlings. CUL-DAR209.8.3. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 7.2022. 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).


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Asparagus Seedlings.

Dec. 29' same plants exposed from 8° 15 to 5° P.m paraffin Lamp.— repainted them all in the morning (See result bottom of last Page

Lamp— 9° 30'— removed 4°. 45'

[Counting of illeg alone]

Jan 2d Same plants grown rather taller

A with Cap .5 deep ie. 1/2 inch— (Plant 1.4 tall) upper part all quite straight

B Cap .35 deep. (Plant ( 2.7 tall) whole summit for 1 inch curved to light

C cap .3 deep. (Plant 1.5 tall) curved for .8 of inch—

Plants from 1 to 2.7 [inch] in length— — Caps of [3 words illeg] from .3 to .5 in depth.—

B D Painted down .3 from apex (Plants 1.1 inch tall) curved for .5 of inch

E Painted down .3 from apex (Plant 1.5 tall) good piece curved to light

5 Plan—

F Painted down .2 from apex (Plant 1.8 tall) curved for .65

In all the other unpainted plant similarly curved— neither caps nor paint seemed to make any difference— Probably whole surface which bends sensitive & upper & younger more sensitive than lower & older part— whole lower part in all straight or vertical

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Dec 27'

Asparagus

 exposed to lamp at 9°. 5' removed at 5° P.m

(1) 7 1/2 /12 inch High — Cap .2 deep— As much curved as any of the free Plant

Dec 29 2 'D' See back. This tallest Plant curved to light

(2) Plant 3/10 high cap .17 deep— as much curved as any of free Plants

Dec. 29th quite e vertical Useless

(3) Plant .37 high — terminal bud 4 1/2 /100 of inch cut off on micrometer

Dec 29' quite vertical nearly as much curved as any

Seedling just under .2 high curved to light.

N.B Consisted of Cot. & bud on fresh internode. This may be cause of no curvature. The cotyledon comes out of a sheath beneath the soil close to seed— so case not parallel with Phalaris & Avena.—

Dec. 28th. 11° a.m

(4 Plants young painted Painted from apex down for .25 of inch all vertical (All the Plants exposed in S.W window Bright day from 11° to 9° 30 & not one of the unpainted plants bent I suppose too cold— close to window & a Frost)

Dec 29' these 4 plants vertical after having been exposed next day to Lamp for whole day.

(Dec 29th There were 9 plants to which nothing had been done & these were all curved to light. The curved part almost horizontal with lower part vertical, so bending does not extend beneath ground so does not only about .15 in length in case of seedlings only .3 to .4 .35 high. With seedling .7 high, curved part exactly half in length a plant only .1 High not curved

Dec 29th

3 Plants with pins (2 taller) painted down from apex for .3 of inch. The tallest of them curved to light, the other 2 vertical.

Next morning (Dec. 30') the 9 unpainted plants had become quite vertical

No evidence of Transmission Try taller plants— depends probably on the stems not being the Cotyledons. I believe that the parts exposed to light alone bend

(over)


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

File last updated 25 September, 2022