[1]

Helianthus

Oct 21' Plant quite free & in light facing N.E. window traced on vertical glass

Left Hand Cot. stood more upright at first than the left Hand [sketch]

See diagram (1) Whole stem bent much to light, which account for decreased movement, but both Cot began had to risen at a little at 12° 3', I do not think this could be Heliotropism ceasing— The left-hand one zig-zags a good deal & it had no occasion to rise so much.

I also measured distance of point of 2 Bristles at 12° 50'; again at 5° P.m. again at 7° 30'; again at 9° 20'; again at 10° 30' & each time they were closer, so that it is certain that they rise & close, beginning to rise at about 12°. Next morning Oct 22d at 7° a.m. they were still a little close closer & formed an angle together of 34°, so that each stood 73° above horizon, & this wd form a considerable protection against radiation. It is certain that the Cots. have diurnal quotidian movement. I shd think some nutation of stem? whether of leaves quite doubtful.

(2

Helianthus

Oct 23d Seedling (same as before). Kept in dark; [sketch]

Nutation of stem traced on Horizontal glass, tracing magnified 21.3 times — Actual movement cd be calculated. Diagram 2. There can be no doubt irregular nutation, about 12° & again in evening

[calculation] 1 .04 actual distance above .1

Hel. annuus (longer

(The upper part of the Hypocot. moved in the very irregular course, during 14 45', shown in the annexed figure, (no' 21) during 14° 45' of observation. As the line rose in same direction, crossing itself several times, the movement may be considered one of circumnutation.

The extreme actual distance travelled was at least .1 of an inch. These cotyledons was behaved in a were [illeg], 2 of them on pl a plant facing a N.E window & the third was so feebly illuminated only from above that it was almost dark: [illeg] All continued sinking till about noon when they began to rise, but from 5° to 7° or 8° P.m. They either sank little or travelled moved horiz laterally & then began again to rise again. At what time in the night or early morning that changed their course & began falling or expanding I do not know. 7° a.m. on following day the cotyledons of the plants stoo close had been exposed to the light on the [prev] day, stood at an angle of 73° above horizon