. The power of movement in plants. Plants; Botany. i;52 MODIFIED CIRCUMNUTATION. Chap. VIH Kig. 17«. eiiipse was completed between 3 and about , tlie hypocotyl still bending towards the light. The hypocotyl was straight and upright in the morn- ing, but by 6 its upper half was bowed towards the hght, so that the chord of the arc thus formed stood at an angle of 20° with the perpendicular. After 6 its course was reversed through the action of apogeotropism, and it continued to bend from the window during the night, as shown by the broken line, On the next day it was kept
. The power of movement in plants. Plants; Botany. i;52 MODIFIED CIRCUMNUTATION. Chap. VIH Kig. 17«. eiiipse was completed between 3 and about , tlie hypocotyl still bending towards the light. The hypocotyl was straight and upright in the morn- ing, but by 6 its upper half was bowed towards the hght, so that the chord of the arc thus formed stood at an angle of 20° with the perpendicular. After 6 its course was reversed through the action of apogeotropism, and it continued to bend from the window during the night, as shown by the broken line, On the next day it was kept in the dark (excepting when each observation was made by the aid of a taper), and the course followed from 7 on the 8th to on the 9th is here likewise shown. The difference between the two parts of the figure (177), namely, that described during the daytime on the 7fh, when exposed to a rather dim lateral light, and that on the 8th in darkness, is striking. The difference consists in the lines during the first day having been drawn out in the direction of the light. The movements of the other seedling, traced under the same circumstances, were closely similar. Apheliotropism.—We succeeded in observing only two cases of aphelio- tropism, for these are somewhat rare; and the movements are generally so slow that they would have been very troublesome to trace. Bignonia capredlata.—No organ of any plant, as far as we have seen, bends away so quickly from the light as do the tendrils of this Bignonia. They are also remarkable from cdrcum- nutating much less regularly than most other tendrils, often remaining Btationary; they depend on apheliotropism for coming into. Bifjnonia capreolata; aphe- liotropic movement of a tendril, traced on a hori- zontal glass from July 19th to 10 20th. Movements as originiilly traced, little magnified, here reduced to two-thirds of the original Please note that these images are extracted from scanned page imag
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
