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"The Power of Movement in Plants"

At I. (Fig. 125) we have a
sketch, made in the middle of the day, of a seedling about a fortnight old.
The two cotyledons, of which Rc is the right and Lc the left one, stand
directly opposite one another,
Fig. 125. Trifolium strictum: diurnal and nocturnal positions of the two
cotyledons and of the first leaf. I. Seedling viewed obliquely from above,
during the day: Rc, right cotyledon; Lc, left cotyledon; F, first true
leaf. II. A rather younger seedling, viewed at night: Rc, right cotyledon
raised, but its position not otherwise changed; Lc, left cotyledon raised
and laterally twisted; F, first leaf raised and twisted so as to face the
left twisted cotyledon. III. Same seedling viewed at night from the
opposite side. The back of the first leaf, F, is here shown instead of the
front, as in II.
and the first true leaf (F) projects at right angles to them. At night (see
II. and III.) the right cotyledon (Rc) is greatly raised, but is not
otherwise changed in position. The left cotyledon (Lc) is likewise raised,
but it is also twisted so that its blade, instead of exactly facing the
opposite one, now stands at nearly right angles to it.


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