to move, and whether the movement when not masked and disturbed by the
straightening process, indicated circumnutation. Firstly a filament was
fixed to the basal leg of an arched hypocotyl close above the summit of the
radicle. The cotyledons were still partially enclosed within the
seed-coats. The movement was traced (Fig. 4) from 9.20 A.M. on Dec.
[page 15]
23rd to 6.45 A.M. on Dec. 25th. No doubt the natural movement was much
disturbed by the two legs having been tied together; but we see that it was
distinctly zigzag, first in one direction and then in an almost opposite
one. After 3 P.M. on the 24th the arched hypocotyl sometimes remained
stationary for a considerable time, and when moving, moved far slower than
before. Therefore, on the morning of the 25th, the glass filament was
removed from the base of the basal leg, and was fixed horizontally on the
summit of the arch, which, from the legs having been tied, had grown broad
and almost flat. The movement was now traced during 23 hours (Fig. 5), and
we

Fig. 5. Brassica oleracea: circumnutating movement of the crown of a buried
and arched hypocotyl, with the two legs tied together, traced on a
horizontal glass during 23 hours. Movement of the bead of the filament
magnified about 58 times, and here reduced to one-half original scale.

see that the course was still zigzag, which indicates a tendency to
circumnutation. The base of the basal leg by this time had almost
completely ceased to move.

As soon as the cotyledons have been naturally dragged from beneath the
ground, and the hypocotyl has straightened itself by growth along the inner
or concave surface, there is nothing to interfere with the free movements
of the parts; and the circumnutation now becomes much more regular and