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"The Power of Movement in Plants"

161). The leaf
continued to rise until 8.50 A.M., then moved a little to the right, and
afterwards descended. Between 11 A.M. and 5 P.M. it circumnutated, and
after the latter hour the great nocturnal fall commenced. At 7.15 P.M. it
depended vertically. The dotted line ought to have been prolonged much
lower down in the figure. By 6.50 A.M. on the following morning (14th) the
[page 384]
leaf had risen greatly, and continued to rise till 7.50 A.M., after which
hour it redescended. It should be observed that the lines traced on this
second morning would have coincided with and confused those previously
traced, had not the pot been slided a very little to the left. In the
evening (14th) a mark was placed behind the filament attached to the apex
of the leaf, and its movement was carefully traced from 5 P.M. to 10.15
P.M.
Fig. 161. Passiflora gracilis: circumnutation and nyctitropic movement of
leaf, traced on vertical glass, from 8.20 A.M. Oct. 13th to 10 A.M. 14th.
Figure reduced to two-thirds of original scale.
Between 5 and 7.15 P.M. the leaf descended in a straight line, and at the
latter hour it appeared vertically dependent.


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