Manito eBooks

On the following day it was observed more
frequently; and two tracings were made (see A and B, Fig. 108), as a single
one would have been too complicated. The apex changed its course 13 times
in the course of 16 h., chiefly up and down, but with some lateral
movement. The actual amount of movement in any one direction was small.
Fig. 108. Eucalyptus resinifera: circumnutation of a leaf, traced, A, from
6.40 A.M. to 1 P.M. June 8th; B, from 1 P.M. 8th to 8.30 A.M. 9th. Apex of
leaf 14 ? inches from the horizontal glass, so figures considerably
magnified.
(17.) Dahlia (garden var.) (Compositae, Fam. 122).--A fine young
[page 245]
leaf 5 3/4 inches in length, produced by a young plant 2 feet high, growing
vigorously in a large pot, was directed at an angle of about 45o beneath
the horizon. On June 18th the leaf descended from 10 A.M. till 11.35 A.M.
(see Fig. 109); it then ascended greatly till 6 P.M., this ascent being
probably due to the light
Fig. 109. Dahlia: circumnutation of leaf, traced from 10 A.M. June 18th to
8.10 A.M. 20th, but with a break of 1 h.


Pages:
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413