. The power of movement in plants. Plants; Botany. 420 MODIFIED dECUSrS'UTATION. Chap VIH rate of bending towards it, and the accuracy with which they point towards its source, &c., will be giren. Afterwards it will be shownâand this seems to us a point of much interestâthat sensitiveness to light is sometimes confined to a small part of the plant; and that this part when stimulated by light, transmits an influence to distant parts, exciting them to bend. Hdiotropism. â When a plant which is strongly heliotropic (and species differ much in this respect) is exposed to a bright lateral light
. The power of movement in plants. Plants; Botany. 420 MODIFIED dECUSrS'UTATION. Chap VIH rate of bending towards it, and the accuracy with which they point towards its source, &c., will be giren. Afterwards it will be shownâand this seems to us a point of much interestâthat sensitiveness to light is sometimes confined to a small part of the plant; and that this part when stimulated by light, transmits an influence to distant parts, exciting them to bend. Hdiotropism. â When a plant which is strongly heliotropic (and species differ much in this respect) is exposed to a bright lateral light, it bends quickly towards it, and the course pursued by the stem is quite or nearly straight. But if the light is much dimmed, or occasionally interrupted, or admitted in only a slightly oblique direction, the course pursued is more or less zigzag; and as we have seen and shall again see, such zigzag move- ment results from the elongation or drawing out of the ellipses, loops, &c., which the plant would have de- scribed, if it had been illuminated from above. On several occasions Beta vulga â â¢$: circnmna- «e WCTC mUch StrUck with this faCt, utionof hypocotvi de- whilst observing the circumnuta- flcctcd by the li^ht . j> i â i i being slightly lateral, tiou 01 highly sensitive Seedlings, T^'fZlt'Trt ''^'''^ ^e^e unintentionally illu- Direction of the minatcd rather obliquely, or only 11"'wi*^''mâ''^i:;!;!;t ^* successive intervals of time. shown by a line ioinin^ -riâ . , j thefirstandpenultimate ^°^ instance, two young seedlmgs of dots. Figure reduced to ^^i<^ vulgaris were placed in the middle one-third of the original of a room with north-east windows, and ^""'^^ â "'ere kept covered up, except during each observation which lasted for only a minute or two ⢠but the result was that their hypocotyls bowed themselves to the side, whence some light occasionaUy entered, in lines which were'. Please note that these i
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
