Of the six radicles
in damp air, three had their tips curved after an interval of 10 h. 15 m.
directly away from the sliced surface, whilst the other three were not
affected and remained straight; nevertheless, one of them after 13
additional hours became slightly curved from the sliced surface. Of the
eight radicles with their tips immersed in water, seven were plainly curved
away from the sliced surfaces after 10 h. 15 m.; and with
[page 167]
respect to the eighth which remained quite straight, too thick a slice had
been accidentally removed, so that it hardly formed a real exception to the
general result. When the seven radicles were looked at again, after an
interval of 23 h. from the time of slicing, two had become distorted; four
were deflected at an angle of about 70o from the perpendicular and from the
cut surface; and one was deflected at nearly 90o, so that it projected
almost horizontally, but with the extreme tip now beginning to bend
downwards through the action of geotropism. It is therefore manifest that a
thin slice cut off one side of the conical apex, causes the upper growing
part of the radicle of this Phaseolus to bend, through the transmitted
effects of the irritation, away from the sliced surface.
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