. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. forming a low dome (Figs. 176, 177) ; the overarching wall does not meet in the middle; and this opening furnishes the inner ring, and the bottom of the pit the outer (Fig. 177). Similar growth takes place in corresponding sides of the wall, and the thin partition soon breaks away (Fig. 178), allowing free communication between the cells. Another method of thickening gives rise to tissue, called coUenchyma; her
. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. forming a low dome (Figs. 176, 177) ; the overarching wall does not meet in the middle; and this opening furnishes the inner ring, and the bottom of the pit the outer (Fig. 177). Similar growth takes place in corresponding sides of the wall, and the thin partition soon breaks away (Fig. 178), allowing free communication between the cells. Another method of thickening gives rise to tissue, called coUenchyma; here the corners of the cell alone become thickened (Fig. 179). 98. In cell-walls considerably thickened, a differentiation into numerous concentric lay- ers is plainly manifest under the tnicroscope ( 180). This is called stratification, and it is due to the fact that alternate layers contain different amounts of water of organization. The dark layers contain less, and the light layers contain more, water. From a study of the stratifi- cation in starch grains, Nageli was led to the conclusion that the molecules of the cell-wall are aggregated into small particles in the form of crys- tals (each of which he called a mi- cella), each surrounded by a layer of water. Wi th larger am ou n ts of water these particles, or micellae, are pushed further apart,_and the layer appears light under the microscope. With a -f decrease of the amount of water the 180. Fig. 179. CoUenchyma. Fig. 180. Hardened cells of the Fear^ in which stratifi- cation is 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 Kellerman, William Ashbrook, 1850-1908. Philadelphia, J. E. Potter and Company
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1883
