. Elements of botany. Plants. STRUCTURE OF THE STEM. 57 oval figures, now show the whole length of the cell, and he may study the way in which they interlock at the ends. In the radial section the medullary rays will frequently look somewhat like portions of brickwork, as shown in Fig. 46. In the tangential section, only the cut-off edges of the medullary rays will be seen, as shown in Fig. 47. 79. SejKirate Wood-Cells. — The com- plete outline of wood-cells and bast-cells is most easily made out by examining cells which have been separated from each other by soaking wood or bark, as the case
. Elements of botany. Plants. STRUCTURE OF THE STEM. 57 oval figures, now show the whole length of the cell, and he may study the way in which they interlock at the ends. In the radial section the medullary rays will frequently look somewhat like portions of brickwork, as shown in Fig. 46. In the tangential section, only the cut-off edges of the medullary rays will be seen, as shown in Fig. 47. 79. SejKirate Wood-Cells. — The com- plete outline of wood-cells and bast-cells is most easily made out by examining cells which have been separated from each other by soaking wood or bark, as the case may be, in a mixture of chlo- rate of potash and nitric acid until it can be easily picked to pieces in water and viewed under the microscope. In this way such cells as those shown in Fig. 48 may be isolated and studied. 80. Ducts of Various Forms. — In most of the hard-woods the ducts are poorly shown in the longitudinal sec- tion, since they usually become much split and broken in the process of cut- ting the Fig. 47. —Longitudinal Sec- tion of Mahogany at right angles to the Medullary Eays, showing their cut- off (Much magni- fied.) Study and sketch some of the following, as seen under a moderately high power : Radial longitudinal section of wood of tulip tree, longitudinal section of stem of bracken fern (Pteris), stem of castor-oil plant (Fig, 49), of peduncle of banana, or of root of chicory or licorice. 81. Kinds of Tissue. — The student has now become acquainted with a few of the many kinds of cells found in plants, and has begun to see how they are grouped together 1 The apparently vacant spaces at the ends of the lens-shaped sections of the medullary rays are in most woods tilled with cells, like the rest of the 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 Berg
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
