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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 6º 45' in my study in window partly widely open.

At 7º 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 12º 18' was at lowest point after the morning.

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

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

After 4º 28' went pretty steadily upwards & at 6º 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 7º 10' A.m. not nearly awake continue very slowly to open & consequently the bristle to sink down till 9º: When I looked at 9º 30' had begun to rise, & so continued till 10º 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 1º 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.—