Cassia tora* (Leguminosae).--A seedling was placed before a
Fig. 25. Cassia tora: conjoint circumnutation of cotyledons and hypocotyl,
traced on vertical glass, from 7.10 A.M. Sept. 25th to 7.30 A.M. 26th.
Figure here given reduced to one-half of original scale.
* Seeds of this plant, which grew near the sea-side, were sent to us by
Fritz M?ller from S. Brazil. The seedlings did not flourish or flower well
with us; they were sent to Kew, and were pronounced not to be
distinguishable from C. tora.
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north-east window; it bent very little towards it, as the hypocotyl which
was left free was rather old, and therefore not highly heliotropic. A
filament had been fixed to the midrib of one of the cotyledons, and the
movement of the whole seedling was traced during two days. The
circumnutation of the hypocotyl is quite insignificant compared with that
of the cotyledons. These rise up vertically at night and come into close
contact; so that they may be said to sleep. This seedling was so old that a
very small true leaf had been developed, which at night was completely
hidden by the closed cotyledons.
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