. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. 84 HISTOLOGY AND PHYSIOLOGY. flowers differ from chlorophyll in that the former appear to be indepeiKlent of light for their production. Flowers ex- panding in the dark have their natural colors. 107. The starch grains arise in the chlorophyll as a product of assimilation. They may be of various shapes, as lenticular in Wheat grains, oval in the Potato, many- sided in Indian Corn, elongated, with enlarged ends,
. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. 84 HISTOLOGY AND PHYSIOLOGY. flowers differ from chlorophyll in that the former appear to be indepeiKlent of light for their production. Flowers ex- panding in the dark have their natural colors. 107. The starch grains arise in the chlorophyll as a product of assimilation. They may be of various shapes, as lenticular in Wheat grains, oval in the Potato, many- sided in Indian Corn, elongated, with enlarged ends, in the milky juice of Euphorbia splendens. The average size and shape of the grains are characteristic for the different plants; and, therefore, when starch is examined microscop- ically, it can be determined from what plant it was ob- tained. Some grains have one nucleus, and are, therefore, sim- ple (Fig. 191) ; others have two or more nuclei, and are com- pound (Fig. 192). Surrounding the nucleus are concentric lay- ers, light and dark alternating, as in the cell-wall, and due to the same cause, namely, greater and lesser amounts of â water contained. The molecular structure is the same as that of the cell-wall, and growth takes place by intussus- ception, or intercalation of particles between those already existing. Chemically, starch resembles sugar and cellulose, and is composed of carbon, hydrogen, and oxygen. It turns a deep blue color when a solution of iodine is applied to it. 108. After starch has been formed in the chlorophyll- bearing cells, it becomes dissolved, and is either consumed at once in the formation of vegetable fabric, or is trans- ported to some other part of the plant, where It reappears. ')(4 3o 191 192 Figs. 191,192. Starchgrains from a Potato: 191. Simple; 192. Compound Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrati
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1883
