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[Phaseolus multiflorus.--Twenty-nine radicles, to which nothing had been
done, growing out of a sieve, were observed at the same time with those
which had their tips greased, and for an equal length of time. Of the 29,
24 curved themselves so as to come into close contact with the bottom of
the sieve. The place of chief curvature was generally at a distance of 5 or
6 mm. from the apex. Eight radicles had their tips greased for a length of
2 mm., and two others for a length of 1 ? mm.; they were kept at a
temperature of 15o - 16o C. After intervals of from 19 h. to 24 h. all were
still vertically or almost vertically dependent, for some of them had moved
towards the adjoining damp surface by about 10o. They had therefore not
been acted on, or only slightly acted on, by the damper air on one side,
although the whole upper part was freely exposed. After 48 h. three of
these radicles became
[page 182]
considerably curved towards the sieve; and the absence of curvature in some
of the others might perhaps be accounted for by their not having grown very
well.


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