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Sept 14. 1878 Heliotropism with very obscure light of Hypocotyls of Celery

Sept. 14' in Study — Pot 42 inches from win N.E. window with ordinary linen & two muslin blinds during whole trial.— From 10° 15' to 1.32 a towel also put over plant.— Muslin removed at 3°. 53' P.m. Sides black— open [sketch] at back to room 2 windows. See Tracings — Fig I more interesting, as after moving straight to light made 1 circumnutation, & then continued to bend greatly to light, so as to be off glass, but was not traced on vertical glass. The 1 circumnutation was not caused by towel temporarily put on, as it did not occur till 2° afterwards

Fig 2. show how straight the seedling bent to this by obscure light; & began to return after 4° 30'

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Sept 16 1878.

Celery

Heliotropism with Obscure light

Study window; pot 42 inches from window.— sides of box. p blackened — roof [sketch] — above — open behind to room, — Window & muslin blind down.— Over the case 2 muslin blinds, (Traced on Horizontal glass) & until 10° 48' a towel, this was then removed & an additional muslin blind put over the case.— So that light now came in through linen linen blind & 4 muslin blinds.— Day in early morning bright, but soon became lightly cloudy Before At 10° 48', a pencil threw no shadow, & the 2 seedlings did not move not move to light & only began to circumnutate irregularly. After 10°. 48 with towel removed pencil cast a br very slight shadow & both seedlings moved to light. See Tracing A & B. — Lines zig-zag with one distinct circumnutation in middle of day. At 4° 28,' as evening beginning to darken one window- muslin-blind removed. At 5° 53' removed 1 muslin blind over case, so that now only window linen blind & 2 muslin.— The zigzagging after 5° 53' evidently evidently due to dim little dull evening light—: returned during night through apogeotropism to about 1/2 way wence whence started. these 2 tracing very [illeg] compared with the 2 on the 14th.

Height of Hypoctyl of left Hand seedling .55 of inch

—— of Right Hand —.5 of inch.