. The power of movement in plants . Plants; Botany. 238 CIECUMNUTATION OF LEAVES. Chap. IV. day. On both days the leaf began to descend after 12 or 1 o'clock, and continued to do so all night, though to a very unequal distance on the Fig. 105. ^'pml". srj5am:i%. â iO'40' two occasions. We therefore thought that the movement was periodic; but on observ- ing three other leaves during several successive days and nights, we found this to be an error; and the case is given merely as a caution. On the third morning the above leaf occupied almost exactly the same position as on the firs
. The power of movement in plants . Plants; Botany. 238 CIECUMNUTATION OF LEAVES. Chap. IV. day. On both days the leaf began to descend after 12 or 1 o'clock, and continued to do so all night, though to a very unequal distance on the Fig. 105. ^'pml". srj5am:i%. â iO'40' two occasions. We therefore thought that the movement was periodic; but on observ- ing three other leaves during several successive days and nights, we found this to be an error; and the case is given merely as a caution. On the third morning the above leaf occupied almost exactly the same position as on the first morning; and the tentacles by this time had unfolded sufSciently to project at right angles to the blade or disc. The leaves as they grow older generally sink more and more downwards. The movement of an oldish leaf, the glands of which were still secreting freely, was traced for 24 h., during which time it continued to sink a little in a slightly zigzag Hne. On the following morning, at 7 , a drop of a solution of carbonate of ammonia (2 gr. to 1 oz. of water) was placed on the disc, and this blackened the glands and in- Drosera rotundifolin: circumnutation of young leaf, with fiiameat fixed to back of blade, from June 7th to June 9th. Figure here reduced to one- half original scale. duced inflection of many of the tentacles. The weight of the drop caused the leaf at first to sink a little; but immediately afterwards it began to rise in a somewhat zigzag course, and continued to do so till 3 It then circumnutated about the same spot on a very small scale for 21 h.; and during the next 21 h. it sank in a zigzag line to nearly the same level which it had held when the ammonia was first administered. By this time the tentacles had re-expanded, and the glands had recovered their proper colour. We thus learn that an old lea*. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabil
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