These facts show that the movement is
independent of geotropism or apheliotropism; it must there[fore] be
attributed to epinasty, which however is checked, at least as long as the
flowers are young, by heliotropism. Most of the above flowers were never
fertilised owing to the exclusion of bees; they consequently withered very
slowly, and the movements of the sub-peduncles were in like manner much
retarded.
To ascertain the nature of the movement of the sub-peduncle, whilst bending
downwards, a filament was fixed across the summit of the calyx of a not
fully expanded and almost upright flower, nearly in the centre of the head.
The main peduncle was secured to a stick close beneath the head. In order
to see the marks on the glass filament, a few flowers had to be cut away on
the lower side of the head. The flower under observation at first diverged
a little from its upright position, so as to occupy the open space caused
by the removal of the adjoining flowers. This required two days, after
which time a new tracing was begun (Fig. 124). In A we see the complex
circumnutating course pursued from 11.
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