. Our field and forest trees. Trees. 198 Our Field and Forest Trees through which air and moisture can pass freely. Some leaves have such pores on their upper sur- faces also, and we find similar tiny openings on green stems, on young fruit, and on branches less than a year old. These openings are " stomata," or mouths. They open into little spaces among the green cells of the leaf, and their use is best described by the word " ; Thanks to them, leaves can breathe away any moisture which the plant does not need. Each mouth opens between two cells (Fig. 50), so
. Our field and forest trees. Trees. 198 Our Field and Forest Trees through which air and moisture can pass freely. Some leaves have such pores on their upper sur- faces also, and we find similar tiny openings on green stems, on young fruit, and on branches less than a year old. These openings are " stomata," or mouths. They open into little spaces among the green cells of the leaf, and their use is best described by the word " ; Thanks to them, leaves can breathe away any moisture which the plant does not need. Each mouth opens between two cells (Fig. 50), somewhat like a pair of lips. Like all their neigh- bor cells, these lips become swollen in moist weather, when water is rising fast from the roots into the foliage, and they shrink and droop in times of drought. When they swell they stand apart so that the little mouth looks as if its lips were whistling, and moisture can pass out between them. Then as soon as the leaf has parted with the moisture it does not need, all its cells become somewhat limp, and the stomata lips droop together so that the mouths are closed (Fig. 51). If leaves get thoroughly soaked, so that water. Fig. 50. Structure of the epider- mis of a leaf, showing the stomata, or little 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 Going, Maud, 1859-1925. Chicago, A. C. McClurg & Co.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttrees, bookyear1916
