After the leaflet was asleep at 6 P.M., and whilst the glass filament hung
[page 373]
perpendicularly down, the movement of its apex was traced until 10.30 P.M.;
and during this whole time it swayed from side to side, completing more
than one ellipse.
Fig 156. Cassia floribunda: circumnutation and nyctitropic movement of a
terminal leaflet (1 5/6 inch in length) traced from 8.30 A.M. to same hour
on following morning. Apex of leaflet 5 ? inches from the vertical glass.
Main petiole 3 3/4 inches long. Temp. 16o - 17 1/2o C. Figure reduced to
one-half of the original scale.
Bauhinia (Tribe 15).--The nyctitropic movements of four species were alike,
and were highly peculiar. A plant raised from seed sent us from South
Brazil by Fritz M?ller, was more especially observed. The leaves are large
and deeply notched at their ends. At night the two halves rise up and close
completely together, like the opposite leaflets of many Leguminosae. With
very young plants the petioles rise considerably at the same time; one,
which was inclined at noon 45o above the horizon, at night stood at 75o; it
thus rose 30o; another rose 34o.
Pages:
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626