18 s.; that is, at very nearly the same rate as before. After another
interval of an hour in darkness, it crossed two divisions in 4 m. 15 s.,
therefore at a quicker rate. In the afternoon, after a longer interval in
the dark, the apex was motionless, but after a time it recommenced moving,
though slowly; perhaps the room was too cold. Judging from previous cases,
there can hardly be a doubt that this seedling was circumnutating.
Fig. 37. Solanum lycopersicum: circumnutation of hypocotyl, with filament
fixed across its summit, traced on horizontal glass, from 10 A.M. to 5 P.M.
Oct. 24th. Illuminated obliquely from above. Movement of bead magnified
about 35 times, here reduced to one-third of original scale.
Solanum lycopersicum (Solaneae).--The movements of the hypocotyls of two
seedling tomatoes were observed during seven hours, and there could be no
doubt that both circumnutated. They were illuminated from above, but by an
accident a little light entered on one side, and in the accompanying figure
(Fig. 37) it may be seen that the hypocotyl moved to this side (the upper
one in the figure), making small loops and zigzagging in its course.
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