During the first day
(22nd) the tip travelled laterally far to the left, perhaps in consequence
of the plant having been
Fig. 117. Crinum Capense: circumnutation of dependent tip of young leaf,
traced on a bell-glass, from 10.30 P.M. May 22nd to 10.15 A.M. 25th. Figure
not greatly magnified.
disturbed; and the last dot made at 10.30 P.M. on this day is alone here
given. As we see in the figure, there can be no doubt that the apex of this
leaf circumnutated.
A glass filament with little triangles of paper was at the same time fixed
obliquely across the tip of a still younger leaf, which stood vertically up
and was as yet straight. Its movements were traced from 3 P.M. May 22nd to
10.15 A.M. 25th. The leaf was growing rapidly, so that the apex ascended
greatly during this period; as it zigzagged much it was clearly
circumnutating, and it apparently tended to form one ellipse each day. The
lines traced during the night were much more vertical than those traced
during the day; and this indicates that the tracing would have exhibited a
nocturnal rise and a diurnal fall, if the leaf had not grown so quickly.
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