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Oct 14th 1878

Phalaris— Glass-Pipes blackened with narrow stripe cleaned of Paint

Heliotropism.— S.W. window

Pipes extending down upper half of seedlings.

Six seedlings thus tried, too young— & the free one were not well inflected to Light ei there sun too hot or sand too dry.— The free ones were all, though not very greatly inflected, & were all most strictly parallel & directed to Light.

(1) & (2) with stripe directed at angle of 2 at 52° from chief source of light & certainly their basal parts halves was bowed in the same direction with their upper parts. &—, that is in the direction of the cleaned stripe.

(3) di with stripe now directed (for I believe had moved) only 18° from source of light & basal part curved in this same direction.

Therefore basal part, though illuminated whole day (from 9° a.m to 4° 30' P.m by bright sky & sun-shine) had not in these 3 cases curved curved to directly to light, but to side on which upper half was illuminated through narrow stripe & we thus clearly see, not only force impulse, but directive impulse transmitted from upper half.—

((4) Vertical, stripe was turned almost directly from light — at so great an angle from source of light that none could have entered at gre in a direct line.

((5) stripe had curved turned round, pipes being lose so as to free from light.— & basal part quite vertical. I suppose that the change of position of the stripes due to growth of cotyledon.

(6) curved from light, but with basal part upright though stripe still directed at angle of 50° from line of light— Weight of Pipe I do not understand this case— stripe ra there broad broad & perhaps somehow obliquely Cot: was somehow obliquely illuminated. on the concave side.

[sketch of finger pointing right] Measure stripe of the 3 with pins

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Oct 15. The cleaned stripes on the 3 which acted well were 5-6/500 = a little over 1/100 of inch wide: 10-13/500 = from 1/50th to little more of inch: & 10/500 = 1/50, but with places b considerably broader

These poor seedlings which grew to very irregular height, were placed behind brown paper behind book-screen & must have been very nearly, if not quite in dark & it is an extraordinary fact that this morning all were found pointing to place whence light had yesterday come shat apogeotropism had down little & what is wonderful, those with black caps & stripes had all changed their positions & now pointed to same source of light, as if the illumination of the basal part during the night had now acted on the basal part & caused them to bend to source of light during the day.— Even if some light had come in during the early morning— room not opened till 6° 15' a.m., it is scarcely credible that those with black caps on shd have been so soon affected for they were looked at about 9°.— It must, I think, be attributed to a strange kind of Nachwirkung of light during day & to the seedlings not being very sensitive to apogeotropism

Left Hand 10-13/500 R 5-6/500 10/500 but with wide places

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Oct 16' 1878 Phalaris with blackened glass pipes on upper half with narrow stripe cleaned on one side of considerable angle to direction of light — Pots not enclosed in Box, before SW. Window— Blind half-down Hazy day.— In 3 Pots; exposed at 9°, 9° 15, 9° 30'.— Examined at. 4° 30 Pot I

Pot I — with Black discs round each seedlings on sand to prevent upwards reflected light, as some of pipes did not fit close.

(1) quite vertical ∠° of stripe of cleaned stripe 84° 62° from line of main light or face of window

(2) quite vertical, angle 50°

(3) quite vertical about 50°

Pot II— little discs of Black paper not put on sand.— Examined 4° 45'

Angles in this pot of direction of the cleaned stripe

(4) angle 50°-60° — inclined so much from light: i.e the seedlings pointed this much from chief source of light— This was certainly & conspicuously the case, as a pins had been laid on surface, showing direction of the cleaned stripe & they all pointed over pins & the contrast most striking between these 3 4 seedlings & all the others in the pot, which were all directed in the straightest & parallel lines to the window & source.

(One of cleaned strips 5—6/500 — The other about 10/500)

(5) like (4)

(6) like (4)

(7) like 4 — All other in Pot 2. arched truly to Light, except 2 or 3 (all ones pulled up.

Pot III With Black paper discs on sand, surrounding seedlings

(8) (9) (10) (11) (12) all these quite vertical!! It is clear that reflection from sand comes into play. — (Angle of deflection of stripe about the same as in 2 other case pots.—) In my former trial no discs were put on sand (sand re yellowish-red colour.) & there was then deflection as in Pot II. in most cases).

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It appears as if the narrow zone of light admitted through stripe to one side of upper part had not power to cause deflection of basal part, unless the upper part be stimulated by a little reflected light coming up on all sides round base of glass-pipe.

All 3 Pots placed in completely dark cupboard

Oct 17th. 8° a.m (1) & (2) Pot I with Black discs had become vertical (3) bowed down at right angle apparently owing to weight

Pot II. no black discs all 4 have become through apogeotropism more upright, but still are directed on same oblique direction, with respect to light—

(Oct 17th 8° 20' Reversed Pot & put before S.W. window) 5° P.m tells nothing for Cots, grown so tall, all curved to light.)

Pot III. with Black discs— 3 of these which had basal part absolutely vertical last night— are now inclined in line of Pins ie at angle with light— — One is vertical & the 5th is bowed from light owing apparently to weight of cap— A very curious case of Nachwirkung

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Oct 17. 1878

Phalaris blackened Glass tubes with cleaned stripe down one side. —

 before S.W. window— Day Hazy

Exposed at 9° 30' — examined at 4° .30' P.m

One Fresh Pot. — Seedlings about high.

Pot not in Box — Blind 1/2 down.

(1) with black disc on sand

(2) do. do

(3) do. do.

(4) bare yellowish sand [*]

(5) do do

(6) do— do.— }All 6 deflected to a point between the line of the stripe & chief source of light.—  there can be no shadow of doubt that the light admitted through the stripes has affected the basal half— The free ones all point to light most truly, when pot viewed from behind, whereas all six with tubes as show their sides owing to deflection—

[*] {Very little difference between those with discs & those with bare sand, yet the latter are a little more curved, & Frank agrees. Angle of divergence of the stripe with most 5 of them 62°— in one only 36°

Angle at which seedling pointed 45° from light

Oct 18th 8° 30' after kept in dark in same position— still directed in same intermediate position— so that the screwing round during night all an illusion

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Oct 18' 1878

Phalaris Glass-pipes painted, with little square window. unpainted, placed obliquely to direction of Light.— Day bright light clouds.— Placed not in Box, in front of S.W. window — Blind half-down.—

Exposed at 9° a.m. ie aft 7°. 40'

(1) 4. 40' quite vertical .63 High, including of course basal part

(2) do. do do

(3) do do .45 high) did not act allude in text—

(4) do do .45 high

(5) basal part curved to light, for window in tube almost faced light (Big Pin) Height .64. Size of window

square window) Has this been used

(6) in all respects like (5) Size of window

Oct 19th I have now measured with micrometer (& tested by looking up to sky) & the "window" was in one 8/500 long & 2/500 wide; in the other 30/500 long & 4/500 wide, & this small amount of light to upper part caused basal part to bend to light.— very good — The 4 others which did not bend (& these & others might be added to list of plain blackened tubes on upper half) had windows about as large as the larger above one, but these were directed at angle between 40° & 60° from chief source of light, & were not sufficient to cause oblique curvature.—

Measure [illeg] window [few words illeg] no movement