movement of which is here shown, would probably have just risen above the
surface of the ground.
Lathyrus nissolia (Leguminosae).--This plant was selected for observation
from being an abnormal form with grass-like leaves.
Fig. 24. Lathyrus nissolia: circumnutation of stem of young seedling,
traced in darkness on a horizontal glass, from 6.45 A.M. Nov. 22nd, to 7
A.M. 23rd. Movement of end of leaf magnified about 12 times, here reduced
to one-half of original scale.
The cotyledons are hypogean, and the epicotyl breaks through the ground in
an arched form. The movements of a stem, 1.2 inch in height, consisting of
three internodes, the lower one almost wholly subterranean, and the upper
one bearing a short,
[page 34]
narrow leaf, is shown during 24 h., in Fig. 24. No glass filament was
employed, but a mark was placed beneath the apex of the leaf. The actual
length of the longer of the two ellipses described by the stem was about
.14 of an inch. On the previous day the chief line of movement was nearly
at right angles to that shown in the present figure, and it was more
simple.
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