M. In the figure as given on
p. 386 (Fig. 163) the first dot was made at 3 P.M.; and the tracing was
continued for the following 65 h. When the leaf pointed to the dot next
above that marked 3 P.M. it stood horizontally. The tracing is remarkable
only from its simplicity and the straightness of the lines. The leaf each
day described a single great ellipse; for it should be observed that the
ascending and descending lines do not coincide. On the evening of the 11th
the leaf did not descend quite so low as usual, and it now zigzagged a
little. The diurnal sinking movement had already commenced each morning by
7 A.M. The broken lines at the top of the figure, representing the
nocturnal vertical position of the leaf, ought to be prolonged much higher
up.
Mirabilis longiflora and jalapa (Nyctagineae).--The first pair of leaves
above the cotyledons, produced by seedlings of both these species, were
considerably divergent during the day, and at night stood up vertically in
close contact with one another. The two upper leaves on an older seedling
were almost horizontal by day, and at night stood up vertically, but were
not in close contact, owing to the resistance offered by the central bud.
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