The
latter part of the course on July 2nd is alone given in the following
figure (Fig. 100). On the next day (July 3rd) the leaf again fell in the
morning, then circumnutated in a conspicuous manner, and rose till late at
night; but the movement was not traced after 7.15 P.M., as by that time the
filament pointed towards the upper edge of the glass. During the latter
part of the night or early morning it again fell in the same manner as
before.
[page 234]
As the evening rise and the early morning fall were unusually large, the
angle of the petiole above the horizon was measured at the two periods, and
the leaf was found to have risen 19o
Fig. 100. Vicia faba: circumnutation of leaf, traced from 7.15 P.M. July
2nd to 10.15 A.M. 4th. Apex of the two terminal leaflets 7 1/4 inches from
the vertical glass. Figure here reduced to two-thirds of original scale.
Temp. 17o - 18o C.
between 12.20 P.M. and 10.45 P.M., and to have fallen 23o 30 seconds
between the latter hour and 10.20 A.M. on the following morning.
The main petiole was now secured to a stick close to the base
[page 235]
of the two terminal leaflets, which were 1.
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