. Elementary botany. Botany. 3o8 ECOLOG V. the pea are broader and shorter than the leaves of the corn, and cannot well form a long pointed covering for the stem. If the stem remained straight the friction of the leaves against the soil would tear them while they are so tender. But lifted out as they are, suspended from the bent stem, they are unharmed. 584. The common garden bean.—The bean also in swelling cracks open the outer coat, the root emerges from underneath the coat in the region of the scar (hilum) on the concave side, while the minute plumule lies curved between the edges of the co
. Elementary botany. Botany. 3o8 ECOLOG V. the pea are broader and shorter than the leaves of the corn, and cannot well form a long pointed covering for the stem. If the stem remained straight the friction of the leaves against the soil would tear them while they are so tender. But lifted out as they are, suspended from the bent stem, they are unharmed. 584. The common garden bean.—The bean also in swelling cracks open the outer coat, the root emerges from underneath the coat in the region of the scar (hilum) on the concave side, while the minute plumule lies curved between the edges of the cotyledons near one end. In the case of the bean, the part of the stem between the cotyledons and the root (called the hypocotyl in all seedlings) elongates, so that the cotyledons are lifted from the soil. The hypo- cotyl is the part of the stem here which becomes strongly curved, and the large cotyledons are dragged out of the soil as shown in fig. 401. The outer coat becomes loosened, and at last slips off com- pletely. The plumule (the young part of the stem with the leaves) is now pushing out from between the cotyledons. As the cotyledons are coming out of the ground the first pair of leaves rapidly enlarge, so that before the stem has straightened up there is a considerable leaf surface for the purpose of car- bon conversion. The leaves are at first clasped together, but as the stem becomes erect. 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 Atkinson, George Francis, 1854-1918. New York, H. Holt and company
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisher, booksubjectbotany
