. Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) Prepared at the request of the Botanical Dept. of Harvard University. Botany; Botany. 86 THE LEAF ^Im The actual motion is often faster than tliis, since tlie for- ward movement is interrupted by retracings of tlie patli and by up and down or oblit^ue deviations from tlie level course. 149. In case a twig or stem of anotlier plant is encoun- tered, the tendril bends round it and the cla\\'cd extieuiities catch in the bark (Fig. Id, (/). Tlie several divisions of tlie tendril, with their numero
. Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) Prepared at the request of the Botanical Dept. of Harvard University. Botany; Botany. 86 THE LEAF ^Im The actual motion is often faster than tliis, since tlie for- ward movement is interrupted by retracings of tlie patli and by up and down or oblit^ue deviations from tlie level course. 149. In case a twig or stem of anotlier plant is encoun- tered, the tendril bends round it and the cla\\'cd extieuiities catch in the bark (Fig. Id, (/). Tlie several divisions of tlie tendril, with their numerous hooks, lay liold on the newly found sujDport. and soon t\\ist about it, Mdiile the rachis shortens by coiling (_Fig. ), in the manner char- acteristic of tendrils. 150. The leaves of insectivorous plants. — The haliitat of insectivorous plants is chiefly marslies, lilce peat bogs. Tliose tliat the student will be most likely to meet are the Sundews and Pitcher Plants. Tlie commonest, Sundew QT)rosiri( rotuiidi- foUa). is a little plant, generally acaulescent, «ith its five or six rounded leaves spread otit horizon- tally in a rosette from two to four inches in diameter. The leaves are thickly set witli hairlike organs (Fig. 70). each tipped «itli a glistening drop of sticky secretion. To judge from the number of small insects, mainly gnats and flies, usually found sticking on the leaves of the Sundew, it seems not luilikely that tlie plants exer- cise upon them some attraction, perhaps tlirough an odor, perhaps only by the brilliance of the clear secretion drops sliining in the sun. and tlie color of the purplish glands. 151. The gland-tipped outgrowths are tentacles. The marginal ones are the longest, and when fully spread out in all directions, double the total diameter of the leaf. If. 76. A leal of Drosera rolundifoHa, or round-leaved Sundew (x2).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readab
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
