. The power of movement in plants . Plants; Botany. 270 MODIFIED CIRCUMNUTATION. Chap. V. yoiuig leaf was traced during ij days, and the tracing here given (Fig. 121) shows that it descended at first in a nearly straight line, but afterwards zigzagged, Fig. Pin^iu' t^rster: epinastic downward movenient of a young leaf, pro- duced by a young plant in a pot, traced on a vei'tical glass under a skylight, from June 2nd to 6th. making one or two little loops. The diverging and descend- ing movements of a rather older leaf were also traced (see former Fig. 113, p. 251): i
. The power of movement in plants . Plants; Botany. 270 MODIFIED CIRCUMNUTATION. Chap. V. yoiuig leaf was traced during ij days, and the tracing here given (Fig. 121) shows that it descended at first in a nearly straight line, but afterwards zigzagged, Fig. Pin^iu' t^rster: epinastic downward movenient of a young leaf, pro- duced by a young plant in a pot, traced on a vei'tical glass under a skylight, from June 2nd to 6th. making one or two little loops. The diverging and descend- ing movements of a rather older leaf were also traced (see former Fig. 113, p. 251): it descended during the first day and night ia a sonie- what zigzag line; it then cir- cumnutated round a small space and again descended. By this time the leaf had nearly assumed its final posi- tion, and now plainly circum- nutated. As in the case of the Carnation, the leaves, whilst very young, do not seem to he much affected by geotropism or heliotropism, for those on a young plant laid horizontally, and those on another plant left upright, both kept in the dark, continued to diverge in the usual manner without bending to either side. With Cohcea scandens, the young leaves, as they succes- sively diverge from the lead- ing shoot which is bent to one side, rise up so as to pro- ject vertically, and th«y retain this position for some time whilst the tendril is revolving. The diverging and ascending movements of the petiole of one such a leaf, were traced on a vertical glass under a sky- light ; and the course pursued was in most parts nearly straight, but there were twc. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Darwin, Charles, 1809-1882; Darwin, Francis, Sir, 1848-1925. New York : D. Appleton
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectplants, bookyear18
