. Foundations of botany. Botany; Botany. LEAVES 137 narrow that no veins of any considerable length could exist except in a position lengthwise of the leaf. The fact that a certain plan of venation is found mainly in plants with a particular mode of germination, of stem structure, and of arrangement of floral parts, is but one of the frequent cases in botany in which the structures of plants are corre- lated in a way which it is not easy to explain. No one knows why plants with two cotyledons should have n e 11 e d-v e i n e d leaves, but many such facts as this are familiar to every botanist.
. Foundations of botany. Botany; Botany. LEAVES 137 narrow that no veins of any considerable length could exist except in a position lengthwise of the leaf. The fact that a certain plan of venation is found mainly in plants with a particular mode of germination, of stem structure, and of arrangement of floral parts, is but one of the frequent cases in botany in which the structures of plants are corre- lated in a way which it is not easy to explain. No one knows why plants with two cotyledons should have n e 11 e d-v e i n e d leaves, but many such facts as this are familiar to every botanist. 147. Simple and Compound Leaves. — The leaves so far studied are simple leaves, that is, leaves of which the blades are more or less entirely united into one piece. But while in the elm the margin is cut in only a little way, in some maples it is deeply cut in toward the bases of the veins. In some leaves the gaps between the adjacent portions extend all the way down to the petiole. Fig. 102.—The Fall of the Horse-Chestnut 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Eastwood, Alice, 1859-1953. Boston, Ginn & Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
