On the following morning (Sept. 25th) the movement of the same cotyledon was again traced in the same manner during 24 h.; and a copy of the tracing is here given (Fig. 25).  The morning was cold, and the window had been accidentally left open for a short time, which must have chilled the plant; and this probably prevented it from moving quite as freely as on the previous day; for it rose only four and sank only four times during the day, one of the oscillations being very small.  At 7.10 A.M., when the first dot was made, the cotyledons were not fully open or awake; they continued to open till about 9 A.M., by which time they had sunk a little beneath the horizon:  by 9.30 A.M. they had risen, and then they oscillated up and down; but the upward and downward lines never quite coincided.  At about 4.30 P.M. the great nocturnal rise commenced.  At 7 A.M. on the following morning (Sept. 26th) they occupied nearly the same level as on the previous morning, as shown in the diagram:  they then began to open or sink in the usual manner.  The diagram leads to the belief that the great periodical daily rise and fall does not differ essentially, excepting in amplitude, from the oscillations during the middle of the day.

Lotus Jacoboeus (Leguminosae).—­The cotyledons of this plant, after the few first days of their life, rise so as to stand almost, though rarely quite, vertically at night.  They continue to act in this manner for a long time even after the development of some of the true leaves.  With seedlings, 3 inches in height, and bearing five or six leaves, they rose at night about 45o.  They continued to act thus for about an additional fortnight.  Subsequently they remained horizontal at night, though still green [page 36] and at last dropped off.  Their rising at night so as to stand almost vertically appears to depend largely on temperature; for when the seedlings were kept in a cool house, though they still continued to grow, the cotyledons did not become vertical at night.  It is remarkable that the cotyledons do not generally rise at night to any conspicuous extent during the first four or five days after germination; but the period was extremely variable with seedlings kept under the same conditions; and many were observed.  Glass filaments with minute triangles of paper were fixed to the cotyledons (1 ½ mm. in breadth) of two seedlings, only 24 h. old, and the hypocotyl was secured to a stick; their movements greatly magnified were traced, and they certainly circumnutated the whole time on a small scale, but they did not exhibit any distinct nocturnal and diurnal movement.  The hypocotyls, when left free, circumnutated over a large space.