All four tracings resembled each other in a
general manner; but we will give only one (see Fig. 122, p. 273). The
filament rose at first, which shows that the hook was straightening itself;
it then zigzagged, moving a little to the left between 9.25 A.M. and 9 P.M.
From this latter hour on the 13th to 10.50 A.M. on the following morning
(14th) the hook continued to straighten itself, and then zigzagged a short
distance to the right. But from 1 P.M. to 10.40 P.M. on the 14th the
movement
Fig. 123. Smithia Pfundii: hyponastic movement of the curved summit of a
stem, whilst straightening itself, traced from 9 A.M. July 10th to 3 P.M.
13th. Apex 9 ? inches from the vertical glass. Diagram reduced to one-fifth
of original scale. Plant illuminated through skylight; temp. 17 1/2o - 19o
C.
[page 275]
was reversed and the shoot became more hooked. During the night, after
10.40 P.M. to 8.15 A.M. on the 15th, the hook again opened or straightened
itself. By this time the glass filament had become so highly inclined that
its movements could no longer be traced with accuracy; and by 1.
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