The pot, in the same position, was next brought back into the light, and
after two days there was some bending downwards of the peduncles, and on
the fourth day two of them pointed to the centre of the earth, as did the
others after an additional day or two. Another plant, in a pot which had
always stood upright, was left in the dark cupboard for six days; it bore 3
peduncles, and only one became within this
Fig. 179. Cyclamen Persicum: downward apheliotropic movement of a
flower-peduncle, greatly magnified (about 47 times?), traced on a
horizontal glass from 1 P.M. Feb. 18th to 8 A.M. 21st.
time at all bowed downwards, and that doubtfully. The weight, therefore, of
the pods is not the cause of the bending down. This pot was then brought
back into the light, and after three days the peduncles were considerably
bowed downwards. We are thus led to infer that the downward curvature is
due to apheliotropism; though more trials ought to have been made.
In order to observe the nature of this movement, a peduncle bearing a large
pod which had reached and rested on the ground, was lifted a little up and
secured to a stick.
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