RECORD: Darwin, C. R. 1864.07.28-08.04. Passiflora gracilis. CUL-DAR157.2.71-72. 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 volumes CUL-DAR157.1-2 contain notes, abstracts etc. for Darwin's long paper and later book Climbing plants (1865). It was also commercially available as a softbound offprint, F834, F834a. See R. B. Freeman's bibliographical introduction. Items CUL-DAR157.11-60 were in a folder marked "Twiners". Items CUL-DAR157.61-112 were in a folder marked "Leaf-climbers" and items CUL-DAR157.114-147 were in a folder marked "Tendrils". Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.


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Passiflora gracilis. July 28 — 64.

Tendrils rubbed 2 or 3 times lightly, far so flexible cannot be rubbed hard, perceptibly curved in 1° much curled into open helix in 2°.— Half-grown tendril not sensitive —

"This elegant & delicate annual species differs from the foregoing other four members of the Family observed by me in the internodes revolving, & they revolve at a quicker rate than in any other known case. — On a hot day, "July 29th the internode moved made six large revolutions following the sun, at average (each differing but little from each other) of in 6° 5', — but the 3 first circles were made at average of 1°. 4; so that 3 last must have been in

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under hour. — The axes were inclined in rather different directions, & sometimes narrow & sometimes broad— mark was fixed to uppermost internode, which must have been carried by that below & probably by one still lower. — — Tendril revolves at about same rate — (The 2 upper internodes do not move — it is the 3d from summit which carries & move the revolving tendril. —

Tendril 7 inches long. — ie. long & thin —

[calculations not transcribed]

Jogging movement— How many internodes move?

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Passiflora gracilis

July 30' seized tendril with one hand rubbed lightly twice & recorded time— held t. close to flat surface & with lens watched movement— began once in 25"— a second time in 31'— This latter tendril had been touched & curled into helix 2 hour previously & had unrolled—

(July 31. t. moved in 32", 31", in 28" & I believe in 20".)

(Aug 1' (1 1/4 inch of thread 1/32' of grain) caused 2 tendrils to certainly move, but then there was some wind in Stove.)

(Aug 1'. Under bell glass the above 1 1/4 of thread clearly acted & caused tip to become fairly hooked. —)

(Aug 2' 1/50 of gr. Platina wire caused 2 tendrils under Bell G. to be more well hooked.) But this did not suffice for permanent curvature. /over

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(Passiflora gracilis)

Try 1 1/4 of Thread— & then pair at tip?

Period of after touch — does it? not move by jerks? How soon gets straight?

Repeated flicking from brush of drops of water no effect. Flicked hard so as to be plainly felt on hand & no one cd feel 1/50' of a grain —

Tendril 8 1/2 inches long.— say from 7 to above 8 inches long —

(Aug 4' Tendril moved in 30". 31" & 39"— say 1/2 minute one in 25'. —)

Spontan (Tendrils sweeping over each other no effect— do not catch each other—)

cannot climb— even when tendrils cut off.


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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 21 July, 2023