. The power of movement in plants. Plants; Botany. 16 CIECUMNUTATION OF SEEDLINGS. Chap. I. two cotyledons parallel to the window. It was thus left the whole daj so as to accommodate itself to the light. On the following morning a filament was fixed to the midrib of the larger and taller cotyledon (which enfolds the other and smaller one, whilst still within the seed), and a mark being placed close behind, the movement of the whole plant, that is, of the hypocotyl and cotyledon, was traced greatly magnified on a ver- tical glass. At first the plant bent so much towards the hght that it was use
. The power of movement in plants. Plants; Botany. 16 CIECUMNUTATION OF SEEDLINGS. Chap. I. two cotyledons parallel to the window. It was thus left the whole daj so as to accommodate itself to the light. On the following morning a filament was fixed to the midrib of the larger and taller cotyledon (which enfolds the other and smaller one, whilst still within the seed), and a mark being placed close behind, the movement of the whole plant, that is, of the hypocotyl and cotyledon, was traced greatly magnified on a ver- tical glass. At first the plant bent so much towards the hght that it was useless to attempt to trace the movement; but at 10 heliotropism almost wholly ceased and tho first dot was Fig. Braasica oleracea- conjoint circumnutation of the hypocotyl and cotyledons during 10 hours 45 minutes. Figure here reducsd to one-half original scale. made on the glass. The last was made at ; seventeen dots being altogether made in this interval of 10 h. 45 m. (see Fig. 6). It should be noticed that when I looked shortly after 4 the bead was pointing off the glass, but it came on again at , and the course during this interval of 1 h. 30 m. has been filled up by imagination, but cannot be far from correct The bead moved seven times from side to side, and thus de- scribed 3J ellipses in 101 h.; each being completed on an average in 3 h. 4 m. On the previous day another seedling had been observed tinder similar conditions, excepting that the plant was so. 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, Appleton
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
