. The power of movement in plants . Plants; Botany. UHAP. 1. SOLANUM. 51 Solarium palinacanthum.—Several arched hypoeotyls rising nearly -2 of an inch above the ground, but with the cotyledons still buried beneath the surface, were observed, and the tracings showed that they circumnutated. Moreover, in several cases little open circular spaces or cracks in the argillaceous sand which surrounded the arched hypoeotyls were visible, and these appeared to have been made by the hypoeotyls having bent first to one and then to another side whilst growing up- wards. In two instances the vertical arche
. The power of movement in plants . Plants; Botany. UHAP. 1. SOLANUM. 51 Solarium palinacanthum.—Several arched hypoeotyls rising nearly -2 of an inch above the ground, but with the cotyledons still buried beneath the surface, were observed, and the tracings showed that they circumnutated. Moreover, in several cases little open circular spaces or cracks in the argillaceous sand which surrounded the arched hypoeotyls were visible, and these appeared to have been made by the hypoeotyls having bent first to one and then to another side whilst growing up- wards. In two instances the vertical arches were observed to move to a considerable distance backwards from the point where the cotyledons lay buried; this movement, which has been noticed in some other cases, and which seems to aid in extracting the cotyledons from the buried seed-coats, is due to the com- mencement of the straightening of the hypocotyl. In order to prevent this latter movement, the two legs of an arch, the Fig. Solanum palinacanthum: circumnutation of an arched hypocotyl, just emerging from the ground, with the two legs tied together, traced in darkness on a horizontal glass, from Dec. 17th to 19th. Movement of bead magnified 13 times ; but the filament, which was affixed obliquely to the crown of the arch, was of unusual length. summit of which was on a level with the surface of the soil, were tied together; the earth having been previously removed to a Uttle depth all round. The movement of the arch during 47 hours under these unnatural circumstances is exhibited in the annexed figure. The cotyledons of some seedlings in the hot-house were hori- zontal about noon on December 13th; and at 10 had risen to an angle of 27° above the horizon; at 7 on the following. 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
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectplants, bookyear18
