All the plants were healthy and grew in pots.
They were illuminated from above, but the light perhaps was not always
sufficiently bright, as many of them were observed under a skylight of
ground-glass. Except in a few specified cases, a fine glass filament with
two minute triangles of paper was fixed to the leaves, and their movements
were traced on a vertical glass (when not stated to the contrary) in the
manner already described. I may repeat that the broken lines represent the
nocturnal course. The stem was always secured to a stick, close to the base
of the leaf under observation. The arrangement of the species, with the
number of the Family appended, is the same as in the case of stems.
Fig. 93. Sarracenia purpurea: circumnutation of young pitcher, traced from
8 A.M. July 3rd to 10.15 A.M. 4th. Temp. 17o - 18o C. Apex of pitcher 20
inches from glass, so movement greatly magnified.
(1.) Sarracenia purpurea (Sarraceneae, Fam. 11).--A young leaf, or pitcher,
8 ? inches in height, with the bladder swollen but with the hood not as yet
open, had a filament fixed transversely
[page 228]
across its apex; it was observed for 48 h.
Pages:
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384