. The power of movement in plants. Plants; Botany. 66 OIKCUMNUTATION OF SEEDLDIGS. Chap. I fig. A filament was next fixed to a cotyledon only i of an inch in heiglit, which was illuminated exclusively from above, and as it was' kept in a warm greenhouse, it grew rapidly; and now there could be no doubt about its circumnutation, for it described a figure of 8 as well as two small ellipses in 5i hours. Nephrodium molle (Filices).—^A seedling fern of this species came up by chance in a flower- pot near its parent. The frond, as yet only slightly lobed, was only '16 of an inch in length and •
. The power of movement in plants. Plants; Botany. 66 OIKCUMNUTATION OF SEEDLDIGS. Chap. I fig. A filament was next fixed to a cotyledon only i of an inch in heiglit, which was illuminated exclusively from above, and as it was' kept in a warm greenhouse, it grew rapidly; and now there could be no doubt about its circumnutation, for it described a figure of 8 as well as two small ellipses in 5i hours. Nephrodium molle (Filices).—^A seedling fern of this species came up by chance in a flower- pot near its parent. The frond, as yet only slightly lobed, was only '16 of an inch in length and •2 in breadth, and was supported on a rachis as fine as a hair and '23 of an inch in height. A very thin glass filament, which projected for a length of 'SB of an inch, was fixed to the end of the frond. The movement was so highly magnified that the figure (Fig. 53) cannot be fully trusted; but the frond was constantly moving in a compltx manner, and the bead greatly changed its course eighteen times in the 12 hours of observation. Within half an hour it often returned in a line almost parallel to its former course. The greatest amount of movement occurred between 4 and 6 The circumnuta- tion of this plant is interesting, because the species in the genus Lygodium are well known to circumnutate conspicuously and to twine round any neighbouring object. Selaginella Kraussii (?) (Lycopodiacefe). —A very young plant, only '4 of an inch in height, had sprung up in a pot in the hot-house. An extremely fine glass fila- ment was fixed to the end of the frond- like stem, and the movement of the bead traced on a horizontal glass. It changed its course several times, as shown in Fig. 54, whilst observed during 13 h. 15 m., and returned at night to a point not far distant from that whence it had started in the morning. There can be no doubt that this little plant circumnutated Nephrodium molle: circnmnutiticn of very young frond, traced in darkness on horizontal glass, from 9 A M.
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
