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Ceropegia Gardnerii (Apocynaceæ) July 21— 63.

Shoot projected horizontally in a inclined direction above stick. The upper internode above pair of half-formed leaves alone moved; for latter faced the same point all day. The upper internode was moving at 8°. a.m. — The apex pointed all round my room: I began to observe at 11° 22'; it completed semicircle in about 4° & circle in 6°. 33' — A second semicircle in 3°. 5'.; & the whole € was completed in 5°. 15' —(a) The movement was reverse of watch hand.— Plant stood in middle of my room. — I fastened thread to eyelet at base of uppermost minute leaves; & saw that this eyelet was first down & then up; in fact revolved like ink-marks on my garters; but it did not roll thread round the shoot; hence no twisting.

The movement is like Man whirling arm round his head in hurray.— but what an illustration which shows better;

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(a) The movements, as shown by thread went on all night. —

Climbers are described by Henslow, (I may say by Botanist), as growing spirally round their support. This is quite incorrect.

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& I give it illustration, as what occurs puzzled me, though probably self-obvious to a geometrician— is to take 3 or 4 parallel string, hold one end firmly, incline the string at say 45° & sweep a circle; & the string will not be twisted: but mark upper surface with black marks dots & these will be seen to turn round so as to be beneath after half circle completed & then up again when circle completed. But now hold a stick almost parallel to string by the fixed hand, & move the other as before; & the parallel string will be wound in a spire round the stick, & now the strings will be twisted round & round, — a twist for each turn of spire; & all this we be see with climbing stems.

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Tendrils are stems, so same movement— How are leaf-tendrils.?

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Ceropegia—

The upper moving [illeg] free internode is not twisted; but round the stick the stem is twisted, as can be seem well in Kidney beans. —??

When I turned garter round empty space, the black mark on upper surface, first above & then below, giving appearance of revolution; (& so with coloured spot on internode) but thread was not twisted round. — When a stick is held in middle opposite sides of garter come into contact & a twist is given; & so it is a spire round an aerial spire. —

July 22d I put stick in course of the many shoot of the Ceropegia, & it pressed against it, & movement at that point stopped, but the free part went

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Ceropegia

(or 4 internodes counting little apex) did wind round stick. Hence lower i

The lower internode had ceased moving. —

Aug'. 10th Put vertical stick at 15 inches from support — after touching rose as usual; owing to resolution of forces, & wound pretty well round; but then slipped off. —

Again I put stick at 21 inches distance the same resulted, the shoot [verily] turned struggled more than once to seize the stick, the elasticity & rigidness of lower internode too much— I then put stick at 26 inches distance (shoot now 31 inches long & still revolving circle of 62 inches!) & the penultimate internode seized it securely & passed nearly twice round it.— The shoot triumphed—

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Times of Ceropegia

6° 33 5° 15} study

6° 45}— Hothouse

7° —top of shoot— study

(there is case of still smaller tip in 9°?? Hot House)