[92]

1878. Action of different degrees of Light at different distances.

Phalaris— too old seedlings

Sept 21'— Hall-lamp — in Frank's room darkened completely.

Pot (1) 2 ft from middle of lamp. Pot (2) 4 ft. Pot (3) (too bad seedlings to trust) (6 ft) — Proved by Plumb-line that stems of 2 seedlings in each pot, vertical, Started at 9° 7' a.m — after 1° certainly no effect— Possibly in 1° 27' the 2 in Pot (1) slight curvature. After 1° 50' the 2 seedlings in (1) almost certainly curved & the right younger Seedling in (2) — Aft 2° 13' no doubt that both in (1) & both I believe, (certainly one) in (2) curved — After 2° 41' one can see without aid of plumb that tips of all 4 seedlings in (1) & (2) curved yet those in (2) received only 1/4 of light of those in pot (1).— After 5° no doubt that seedlings in (1) more curved than in (2) & no doubt from former experiments that plant seedlings in (1) wd. havebeen very much more curved, if they hadbeen exposed to bright light.— no effect in Pot. 3 but these seedlings bad. At 3° P.m. after 5° 45' same state of things, but when I looked after addition 1° 30', (i.e at 4° 30') lamp gone out.— & I believe apogeotropism had made seedlings more upright. in Pot (1) angle of chord

20° from perpendicular 11° —} mean 15 1/2°

In Pot (2 — 14 1/2 4°} mean 9 1/4