These
oscillations were exactly like those described under Brassica and Dionaea,
but they occurred only occasionally. We may therefore conclude that this
moderately old joint was continually circumnutating on a small scale.
Alopecurus pratensis.--A young plant, 11 inches in height, with the
flower-head protruded, but with the florets not yet expanded, had a glass
filament fixed close above the second joint, at a height of only 2 inches
above the ground. The basal internode, 2 inches in length, was cemented to
a stick to prevent any possibility of its circumnutating. The extremity of
the filament, which projected about 50o above the horizon, was often
observed during 24 h. in the same manner as in the last case. Whenever
looked at, it was always in movement, and it crossed 30 divisions of the
micrometer (3/50 inch) in 3 ? h.; but it sometimes moved at a quicker rate,
for at one time it crossed 5 divisions in 1 ? h. The pot had to be moved
occasionally, as the end of the filament travelled beyond the field of
vision; but as far as we could judge it followed during the daytime a
semicircular course; and it certainly travelled in two different directions
at right angles to one another.
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