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[page 63]
action of light; and if any enters even temporarily on one side, they
merely bend to this side in slightly zigzag lines. Of the three tracings
one alone (Fig. 49) is here given. Had the observations been more frequent
during the 12 h. two oval figures would have been described with their
longer axes at right angles to one another. The actual amount of movement
of the apex from side to side was about .3 of an inch. The figures
described by the other two seedlings resembled to a certain extent the one
here given.
Fig. 49. Phalaris Canariensis: circumnutation of a cotyledon, with a mark
placed below the apex, traced on a horizontal glass, from 8.35 A.M. Nov.
26th to 8.45 A.M. 27th. Movement of apex magnified 7 times, here reduced to
one-half scale.
A seedling which had just broken through the ground and projected only
1/20th of an inch above the surface, was next observed in the same manner
as before. It was necessary to clear away the earth all round the seedling
to a little depth in order to place a mark beneath the apex. The figure
(Fig.


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