(5X

(Ceropegia)

on curving round stick, after one hour, I marked point toward which shoot pointed— The 2 lower leaves were moved a little by force of apex curling but came back to original place. I think it performed semicircle in 4°. 20'; when it had performed nearly rather more than semicircle in 6°, the shoots ceased to move laterally but mounted upwards & in 1°. 40' slipped off stick & assumed its original position & began to revolve again as if to attempt to catch wind round stick—The stick had been placed too near tip as plant apparently makes very open spire. — N.B. stick was inclined.

I set inclined stick to base of upper internode.— but again in course of the night it slipped off.—

July 23 put stick perpendicular at 11°. 30' A.m.

(6X

By 9°. (ie in 9° 30',) the shoot in open spire had elegantly clasped stick.; so that it is clear that movement retarded (when shoot free it took 6°. 30' & 5° 15' to perform circle) & there is no need of any irritability. The whole simple result of the movement.— I think thread now wound round shoot. for it always depended. — During the night the shoot to extremest tip clasped stick, & thread was wound up as if in reversed direction to that which shoot itself must have twisted owing to going round stick. 24th At 9° A.m, I removed stick; in course of day the shoot straightened, itself; the upper 2 1/2 inches of internode began at once revolving & completed € in 7°; but the lower part of the internode hardly moved at all; so separation of movement in upper third of internode I put stick to lower internode all day but produced no effect.—

[6Xv]

July 26th I now find that thread is wound round shoot of Ceropegia by its revolution whilst free, & so a perpendicular thread with weight is round Garter; but this Does not imply twisting. It passed 3 times round shoot in 24°, but I suspect once or twice it slipped off, from shoot being too upright.—

In the plants round stick, I at times was perplexed by thread being apparently too much wound up, which would result, as both causes would act.—

(6 bis X

Aug 1st.

Ceropegia

The internode which I watched has now grown to length of 10 inches & is surmounted by one of 8 & this by small bent young internode. The whole of 10 inch internode has recovered power of movements & sweeps a great circle reverse of watch: I put vertical stick (N.B inclined would not have done) at 17 inches distance & it was caught by upper portion & wound round: But it must not be supposed that it sweeps twice 17 inches; for on opposite side it rises in sweeping to more upright position— Wonderful has not been observed. —

(6 tres X

Ceropegia

Aug. 7th. The shoot has now 3 long internodes surmounted by 2 little ones an inch or two long — It now sweeps a circle 4 ft by measure in diameter; the shoot extending nearly horizontally; & top of older internode is bent by weight.— Sometimes shoot becomes more upright.

I have positively ascertained that all these 3 internodes move, (contrast with Roxburghia & Sphærostema). It is a wonderful sight to watch the movement— It sweep a circle of 12ft

I have just found that it in Hothouse performed the circle in

Therefore the tip travelled at

Aug 7th In Hot-house made circuit, not complete in 5°. 30' probably wd have taken 1° more.—

[6 tres Xv]

Circumference = diameter x 3 + 1/7 of diameter.

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Therefore end of shoot travelled at rate of 25 inches per hour.

(6(4)X

Ceropegia

Aug 8th I have now ascertained € complete in 6°. 3/4. The tip travelled 12.6 in this time, not quicker in Hothouse than in my room.—

Aug 9th. The shoot now extends horizontally 29 inches, but as tip often curled in say 27 inches.— ∴ circle of 4 ft 6 was swept— I put today vertical stick; shoot hardly moved for 2 hours & this seemed clearly connected with curling its tip in right direction; it then started & curled above 90°, rising as it curled & met resistance; this always occur when motion arrested. But elasticity of lower long, straight internodes was too much & it suddenly swung back & slowly began movement again.

6(5) X

Ceropegia.

Under nature there would not be vertical stick on old line & a swinging shoot would meet with stick at some upper direction, where less rigid upper internodes would climb it.

Hence movement continues longer than flexibility.

(With allied Cryptostegia case is rather different:— I allowed shoot to grow 31 inches above supporting stick, but the lower internode became gradually straight & upright & stiff enough to support the remaining internodes: now when I put vertical stick along side former stick the 3 lower internodes 14 inches in length did not wind round it, except a mere touch towards upper end,; but the 3 short upper internodes

[6(5) Xv]

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