. A text-book of botany for secondary schools. Botany. GERMINATION OP SEEDS 89 plant in various compounds found in the soil. The white of an egg is an illustration of a proteid; and meat in general is a proteid food, as contrasted with bread, which is a car- bohydrate food. In many seeds proteid food is stored in the form of uleuronc grains. For example, a section of a wheat grain, or the grain of any common cereal, shows aleurone grains in the outer layer of endosperm cells, just inside of the testa; while the other endosperm cells contain starch grains. 50. Fats.âIn addition to carbohydrates
. A text-book of botany for secondary schools. Botany. GERMINATION OP SEEDS 89 plant in various compounds found in the soil. The white of an egg is an illustration of a proteid; and meat in general is a proteid food, as contrasted with bread, which is a car- bohydrate food. In many seeds proteid food is stored in the form of uleuronc grains. For example, a section of a wheat grain, or the grain of any common cereal, shows aleurone grains in the outer layer of endosperm cells, just inside of the testa; while the other endosperm cells contain starch grains. 50. Fats.âIn addition to carbohydrates and proteids, some plants form fats, the third kind of organic food; and these fats are sometimes stored in the seeds in liquid form (in small drops), as in the castor-bean, flaxseed, etc. Fats contain carbon, hydrogen, and oxygen as do the carbo- hydrates; but while in the carbohydrates the hydrogen and oxygen occur in the proportion of two to one (H2O), in the fats the proportion of oxygen is much less. In ad- dition to the oil obtained from the seeds mentioned above, olive oil and cotton-seed oil may be mentioned as plant fats of commercial importance. 51. Escape of the hypocotyl.âThe first part of the seedling to push out of the testa is the tip of the hy- pocotyl, which is to develop the root. It is soon evident that this elon- gating tip di- rects its growth downward, that is, toward the earth, even if it has to curve about the seed to do so (Fig. 83). It is exceedingly sensitive to surrounding influ-. Fig. 83 â Germinating beans: the bean to the left has not been moved; the one to the right was turned 90° after it had reached the stage of the other. 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 Coulter, John Merle, 1851-1928. New York, D. Appleton
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1906
