(1

Sida corolifolia

Young plant 9 1/2 inches high.— Glass filament with 2 triangle of paper fixed to 3d leaf from apex, nearly fully-grown 2 3/8 inches long, traced on vertical glass— under skylight. But day rather cold 15°—16° cent. & poor illumination & the leaves did not rise so vertically as in Hot-House. Tracing A shows that leaf circumnutated for did not ascend & descend on same line.—

On the 25th descended but only for short distance from 9° 15' am till 5°. 15' P.m, for by 5° 55' had risen a little & had travelled laterally. Between 6° P.m & 10. 50' P.m. rose rapidly & greatly. Next day between 6° 40 & 9° fell rapidly & greatly & stood nary in same position as yesterday, & then behaved like yesterday, zig-zagging between 2° & 5° & by 6° 5' had risen, & then rose rapidly but not so high as previous night probably owing to cold.

Stem was secured to stick close beneath base of petiole of leaf Apex of leaf 5 5/8 from vertical glass

May 30th. Seeing how complex the movement were at time & point when the descending movement in evening changed into nocturnal, I resolved to observe more frequently the movements of same leaf with same filament in same position, except that the Tracing was more magnified, as the pot was withdraw so that apex of leaf was 9 inches from vertical glass— A dot

(2

Sida

was made every 1/2 hours from 4° P.m to 10° 30' P.m. & the tracing was continued next day to nearly noon.

We see close resemblance between this tracing B & that of A. The zig-zagging is strikingly like Heliotropism when light is weak or fails for a time — This case seem good evidence of circumnutation modified into Sleep movement.