. The power of movement in plants . Plants; Botany. 32 CIECUMNUTATION OF SEEDLINGS. Chap. L two occasions during three days. But the tracings made under such unnatural conditions are not worth giving; and it need only be said that the lines were decidedly zigzag, and that small loops were occasionally formed. We may therefore con- clude that the epicotyl circumnutates whilst, still arched and before it has grown talL enough to break through the surface of the ground. In order to observe the movements of the epicotyl at a some- what more advanced age, a filament was fixed near the base of one w
. The power of movement in plants . Plants; Botany. 32 CIECUMNUTATION OF SEEDLINGS. Chap. L two occasions during three days. But the tracings made under such unnatural conditions are not worth giving; and it need only be said that the lines were decidedly zigzag, and that small loops were occasionally formed. We may therefore con- clude that the epicotyl circumnutates whilst, still arched and before it has grown talL enough to break through the surface of the ground. In order to observe the movements of the epicotyl at a some- what more advanced age, a filament was fixed near the base of one which was no longer arched, for its upper half now formed a right angle with the lower half. This bean had germinated on bare damp sand, and the epicotyl began to straighten itself much sooner than would have occurred if it had been properly planted. The course pursued during 50 h. (from 9 Dec. 26th, to 11 28th) is here shown (Fig. 22); and we see Fig. Vicia fdba: circumnutation of young epicotyl, traced in darkness during 50 hours on a horizontal glass. Movement of bead of filament mag- nified 20 times, here reduced to one-half of original scale. that the epicotyl circumnutated during the whole time. Its basal part grew so much during the 50 h. that the filament at the end of our observations was attached at the height of '4 inch above the upper surface of the bean, instead of close to it. If the bean had been properly planted, this part of the epicotyl would still have been beneath the soil. Late in the evening of the 28th, some hours after the above observations were completed, â the epicotyl had grown much straighter, for the upper part now formed a widely open angle with the lower part. A filament was fixed to the upright basal part, higher up than before, close beneath the lowest scale-lika process or homologue of a leaf; and its movement was traced. Please note that these images are extracted from scanned page images that may have been digitally enhanced f
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectplants, bookyear18
