M. and 4.30 P.M. On the second
day it sank and rose again, but between 10 A.M. and 6 P.M. it circumnutated
on an extremely small scale. On the third day the circumnutation was more
plainly marked.
(8.) Cissus discolor (Ampelideae, Fam. 67).--A leaf, not nearly full-grown,
the third from the apex of a shoot on a cut-down plant, was observed during
31 h. 30 m. (see Fig. 99). The day was cold (15o - 16o C.), and if the
plant had been observed in the hot-house, the circumnutation, though plain
enough as it was, would probably have been far more conspicuous.
Fig. 99. Cissus discolor: circumnutation of leaf, traced from 10.35 A.M.
May 28th to 6 P.M. 29th. Apex of leaf 8 3/4 inches from the vertical glass.
(9.) Vicia faba (Leguminosae, Fam. 75).--A young leaf, 3.1 inches in
length, measured from base of petiole to end of leaflets, had a filament
affixed to the midrib of one of the two terminal leaflets, and its
movements were traced during 51 ? h. The filament fell all morning (July
2nd) till 3 P.M., and then rose greatly till 10.35 P.M.; but the rise this
day was so great, compared with that which subsequently occurred, that it
was probably due in part to the plant being illuminated from above.
Pages:
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393