(1

Cassia floribunda

Nov 7' Nov 29. 1873.

(See Linneus on sleep). The leaflets during the day are horizontal, but as the main petiole of the younger leaves generally slopes a little upwards, the front margin of the leaflets is a little depressed, so that the blade may be horizontal. In some of the older leaves which droop a little downwards the front margin is a little raised for the same purpose. At 4. p.m. the leaflets & midribs were nearly horizontal (see whether not judging from position on the 30th at 4° 15' P.m in Hot-House a little inclined downwards)

[1v]

[calculation not transcribed]

(2

the very short sub-petioles had twisted round 90°, so that all the leaflets on the old & young leaves stood vertically like Eucalypti. By 4. 50' the leaflets had become so much twisted round that the lower bloom-coloured surface looked directly upwards, & hence the very short peduncle must have been twisted 180° & at the same time the leaflets had become so much depressed that the 2 opposite ones instead of going in a horizontal plane, formed with each other an angle of only 54°.

Therefore each leaflet was 27° from the perpendicular & had moved downward through 63° & stood at 63° to the horizon. But this movement occurred only in the younger leaves at the summit of the shoots; the older leaves remaining vertical all night. We see that in my study the upper & inverted surfaces