M. on February 18th; and
from this hour till 3 P.M. the
[page 42]
cotyledon fell; it then rose rapidly till 9 P.M., then very gradually till
3 A.M. February 19th, after which hour it sank gradually till 4.30 P.M.;
but the downward movement was interrupted by one slight rise or oscillation
about 1.30 P.M. After 4.30 P.M. (19th) the cotyledon rose till 1 A.M. (in
the night of February 20th) and then sank very gradually till 9.30 A.M.,
when our observations ceased. The amount of movement was greater on the
18th than on the 19th or on the morning of the 20th.
Cucurbita aurantia.--An arched hypocotyl was found buried a little beneath
the surface of the soil; and in order to prevent it straightening itself
quickly, when relieved from the surrounding pressure of the soil, the two
legs of the arch were tied together. The seed was then lightly covered with
loose damp earth. A filament with a bead at the end was affixed to the
basal leg, the movements of which were observed during two days in the
usual manner. On the first day the arch moved in a zigzag line towards the
side of the basal leg.
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