. The power of movement in plants . Plants; Botany. 28 CIECUMNUTATION OP SEEDLINGS. Chap. I Citrus aurantium (Orange) (AurantiaceaB).—The cotyledons are hypogean. The circumnutation of an epicotyl, which at the close of our observations was -59 of an inch (15 mm.) in height above the ground, is shown in the annexed figure (Fig. 17), as observed during a period of 44h. 40 m. Fig. Citrus aurantium: circumnutation of epicotyl with a filament fixed traus- versely near its apex, traced on a horizontal glass, from on Feb. 20th to on 22nd. The movement of the bead of the fil
. The power of movement in plants . Plants; Botany. 28 CIECUMNUTATION OP SEEDLINGS. Chap. I Citrus aurantium (Orange) (AurantiaceaB).—The cotyledons are hypogean. The circumnutation of an epicotyl, which at the close of our observations was -59 of an inch (15 mm.) in height above the ground, is shown in the annexed figure (Fig. 17), as observed during a period of 44h. 40 m. Fig. Citrus aurantium: circumnutation of epicotyl with a filament fixed traus- versely near its apex, traced on a horizontal glass, from on Feb. 20th to on 22nd. The movement of the bead of the filament was at first magnified 21 times, or 10^, in figure here given, and afterwards 36 times, or 18 as here given; seedling illuminated from above. ^sculus hippocastanum (Hippocastaneae).—Grerminatiag seeds were placed in a tin box, kept moist internally, with a sloping bank of damp argillaceous sand, on which four smoked glass- plates rested, inclined at angles of 70° and 65° with the horizon. The tips of the radicles were placed so as just to touch the upper end of the glass-plates, and, as they grew downwards they pressed lightly, owing to geotropism, on the smoked surfaces, and left tracks of their course. In the middle part of each track the glass was swept clean, but the margins were much blurred and irregular. Copies of two of these tracks (all four being nearly alike) were made on tracing paper placed over the glass-plates after they had been varnished; and they are as exact as possible, considering the nature of the margins (Fig. 18). They suffice to show that there was some lateral, almost serpentine movement, and that the tips in their down- ward course pressed with unequal force on the plates, ae. 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, S
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