[83]

Aug. 27th 1878 Canary grass Light. Painted useless

Cloudy & Sun-shine alternately

3 with upper half & 3 with lower half (beneath earth); Halves not measured; painted with thick Indian ink & placed before S.W window—very dark rainy day all morning; afternoon some sun: placed in box at 8°. 45'

4° 35' P.m .3 of which tips upper half painted are quite straight relatively to light, but they have retained slight curvature, which they had before being painted.

4°. 35 P.m. 3 of which lower half painted are straight relatively to light, with the upper half slightly curved towards light—

It appears from these observations that when upper part is painted this stops the lower uncurved unpainted part from bending at all; whereas basal part being painted only stops this basal part bending, the upper part becoming curved; yet it is the basal part which curves most. This, however, may be due to upper half, as it seems being fo directed towards light so that its surface is exposed only obliquely, whereas lower part, being held by ground continues exposed

(I must study how a free plant curves whether tip or base curves first for ultimately whole upper part curved used to become straight.)

Aug 28th 8° 30' Painted in same manner 2 upper Half— & 2 lower half (measured) (lower Half beneath earth) & exposed in same manner in blackened box — deeper than yesterday S.W. window morning bright.

(1) 4° 50' (1) upper half painted, as much curved to light as any, but paint has is removed from one side not that facing light & blades or true leaves have come out of apex — Paints stretches owing to protrusion of young leaves.

(2) painted like (1) almost quite upright & differs conspicuously from all other seedlings— paint broken on side from light— the paint is also cracked close to apex on side to light, & apex is curved a little to light.

(3) 5° P.m upper Half— as much curved as any: basal half almost perpendicular & less bowed than most others of same height & age.— doubtful

(4) 5° P.m. Bowed laterally & not to light. I do not understand this case

[84]

Sept 1. 1878 Canary-grass—seedlings Light

Painted Useless

8° 30' a.m. painted upper (by eye) half of 5 & lower half of 5 seedlings— raised in dark- cupboards & exposed in blackened box before S.W. window — day dull

(10° 20' uppermost part of all uncoloured ones plainly curved to light; also tips of those whose basal parts are coloured.)

(11° 30' . The upper part of uncoloured seedlings much curved to light— lower part not yet curved— marked 3 with pins in this state. One of those painted in upper half— had become a little bare on side to light repainted— Pin on soil. —

Those painted at base had tips curved considerably— Those with upper half— painted quite straight.

(Can whole case be that lower part less sensitive & requires longer exposure to light to be acted on?? or is effect propagated downwards??)

(12.°. 45'. nearly same state, but curvature has now descended lower down the in the unpainted ones & the upper part which was arched is becoming straight—Those with bases painted have still upper unpainted parts arched.)

(2° 20' nearly same state, all characters more marked— some of young seedlings quite prostrate.)

(Examined at 4° 45' P.m. of the 5 with upper half painted all may be said roughly & in contrast with the unpainted ones, to be straight; but 2 of the 5 when examined critically were a trace curved yet as nothing in comparison with the unpainted.

Of the 5 with basal halves painted; the basal part of all straight, whereas the upper unpainted portion in 4 of them curved to the light in plainest manner. Therefore certainly an effect is transmitted from upper part to basal part & not reversely.— By actual measurement, the with those

(over)

[84v]

Canary-grass—

having upper half painted the basal part was quite straight at distance above ground whereas the unpainted ones were greatly & often rectangularly bent.

N. B. There is great variability in degree to which the seedlings are acted on — some have whole upper part horizontal & then have become in this part straight ie have lost their curvature in morning. — Others are curved in various degrees. Two seedlings rather tall ones, had a basal part to length of .25 & .35 of inch not curved! so that variability in part which curves are sensitive or which curve.

(5° 10' P.m Both pots laid horizontally (to see whether blackened parts will turn up.—