. The power of movement in plants . Plants; Botany. 18 CIBCUMNUTATION OF SEEDLINGS. Chap. ) A M. When again looked Fig. '. at'} 10°. Iponuea carulea : circumnntation of cotyledon, traood on vertical glass, from June 21st to 22nd. Cotyledon with petiole 1 ⢠6 inch in length, apex of blade 4'1 inch from the vertical glass; so movement not greatly mag- nified; temp. 20° C. at, at (21st), it had fallen largely. A new tracing â was now begun (see Fig. 35), and soon afterwards, at , the cotyledon had risen a little. During the for
. The power of movement in plants . Plants; Botany. 18 CIBCUMNUTATION OF SEEDLINGS. Chap. ) A M. When again looked Fig. '. at'} 10°. Iponuea carulea : circumnntation of cotyledon, traood on vertical glass, from June 21st to 22nd. Cotyledon with petiole 1 ⢠6 inch in length, apex of blade 4'1 inch from the vertical glass; so movement not greatly mag- nified; temp. 20° C. at, at (21st), it had fallen largely. A new tracing â was now begun (see Fig. 35), and soon afterwards, at , the cotyledon had risen a little. During the forenoon it was observed about every hour; but between and 6 every half-hour. If the observations had been made at these short intervals during the whole day, the figure would have been too intricate to have been copied. As it was, the cotyledon moved up and down in the course of 16 h. 20 m. (i e. between aLd ) thirteen times. The cotyledons of this seed- ling sank downwards during both evenings and the early part of the night, but rose during the latter part. As this is an unusual movement, the cotyledons of twelve other seed- lings were observed; they stood almost or quite horizontally at mid-day, and at 10 were all declined at various angles. The most usual angle was be- tween 30° and 35°; but three stood at about 50° and one at even 70° beneath the horizon. The blades of all these cotyle- dons had attained almost their full size, viz. from 1 to \\ inches in length, measured along their midribs. It is a remarkable fact that whilst youngâthat is, when less than half an inch in length, measured in the same mannerâthey do not sinb. 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, Sir, 1848-1925. New York : D. Ap
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectplants, bookyear18
