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Cassia. St. Catharina seeds F. Muller 1877

Sept 24th

Cotyledon close at night almost completely & embrace young leaflets & plumule, standing vertically.

Sept. 24 at 6° 45' in my study in window partly widely open.

At 7° 50' first dot on vertical glass, where both cots standing almost horizontally open but afterwards opened a little more stem not tied during day the Cots. become slightly oblique towards light, & young stem also bent a little to light.— The specimen observed had minute tuft of leaves in centre, hidden when cots. closed at night.

At 12° 18' was at lowest point after the morning.

At 2° 17 remained for 23' on same spot or came back to —

Between 7° 50' & 5° (ie 9° 10') went up 5 times & 5 times down.

After 4° 28' went pretty steadily upwards & at 6° 50' was beyond glass. Movements can be of no functional use.— Movements probably rather greater— & probably greater in Hot-house

Sept 25' Observed the same Plant again: morning frosty & window was accidentally left open so that plants much chilled: at 7° 10' A.m. not nearly awake continue very slowly to open & consequently the bristle to sink down till 9°: When I looked at 9° 30' had begun to rise, & so continued till 10° 24' when first downward movement commenced: (see diagram.) All movements slower & less complicated, but evidently of same general character. It is odd that the chilling cold made Cotyledons sink beneath a horizontal position & this made the first rise so late.

At 1° at lowest point. Twice remained at same point for 15' & 13'. The Cot. opened slightly to light during day & in early mornings when coming down or opening recover its former position so that lines oblique on glass & nearly parallel.— Four times down, but

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one very short & 4 times up. It looks to me as if there was some necessity for plant moving, & that 2 great up & down movement made for purpose, & in middle of day forces expended in useless up & down movements. This my theory.—