Lynch's and our own observations, their
inclination during the day is determined by the intensity of the light. On
the third day, by which time the extent of the descending movement had much
decreased, the line traced was plainly much more zigzag than on any
previous day, and it appeared as if some of its powers of movement were
thus expended. At 10 P.M. on June 7th, when the leaf depended vertically,
its movements were observed by a mark being placed behind it, and the end
of the attached filament was seen to oscillate slowly and slightly from
side to side, as well as upwards and downwards.
Phyllanthus Niruri (Euphorbiaceae).--The leaflets of this plant sleep, as
described by Pfeffer,* in a remarkable manner, apparently like those of
Cassia, for they sink downwards at night and twist round, so that their
lower surfaces are turned
* 'Die Period. Beweg.,' p. 159.
[page 389]
outwards. They are furnished as might have been expected from this complex
kind of movement, with a pulvinus.
GYMNOSPERMS.
Pinus Nordmanniana (Coniferae).--M. Chatin states* that the leaves, which
are horizontal during the day, rise up at night, so as to assume a position
almost perpendicular to the branch from which they arise; we presume that
he here refers to a horizontal branch.
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