3 of inch in diameter) buried itself in sawdust for three-quarters of
its length.** We shall have occasion hereafter to consider the object
gained by this burying process. The peduncles can change the direction of
their curvature, for if a pot, with plants having their peduncles already
bowed downwards, be placed horizontally, they slowly bend at right angles
to their former direction towards the centre of the earth. We therefore at
first attributed the movement to geotropism; but a pot which had lain
horizontally with the pods
* 'The Movements and Habits of Climbing Plants,' 1875, p. 97.
** The peduncles of several other species of Cyclamen twist themselves into
a spire, and according to Erasmus Darwin ('Botanic Garden,' Canto., iii. p.
126), the pods forcibly penetrate the earth. See also Grenier and Godron,
'Flore de France,' tom. ii. p. 459.
[page 434]
all pointing to the ground, was reversed, being still kept horizontal, so
that the pods now pointed directly upwards; it was then placed in a dark
cupboard, but the pods still pointed upwards after four days and nights.
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