. Agricultural botany, theoretical and practical. Botany, Economic; Botany. ANNUAL-RINGS : KNOTS 123 present, and a similar addition is made to the bast on its inside. The amount of wood produced by the cambium is always very much greater than the bast. Moreover, the bast tissue consists chiefly of thin-walled elements which become crushed into very thin sheets by the pressure of the expanding wood and the re- sistent bark, whereas the wood with its thick-walled cells and vessels suffers little in this manner; in transverse sections of the ^T A—. Fig. 57.—I. Piece of a stem of an ash tree. A,
. Agricultural botany, theoretical and practical. Botany, Economic; Botany. ANNUAL-RINGS : KNOTS 123 present, and a similar addition is made to the bast on its inside. The amount of wood produced by the cambium is always very much greater than the bast. Moreover, the bast tissue consists chiefly of thin-walled elements which become crushed into very thin sheets by the pressure of the expanding wood and the re- sistent bark, whereas the wood with its thick-walled cells and vessels suffers little in this manner; in transverse sections of the ^T A—. Fig. 57.—I. Piece of a stem of an ash tree. A, Portion three years old ; £, portion two years old. 2. Longitudinal and transverse sections of same. trunks and branches of trees and shrubs the cambium appears to the naked eye to produce wood only. (i) Annual rings: knots.—If a tree is sawn across and the cut surface then smoothed with a chisel a number of ring-like zones are noticeable in the wood (Figs. 57 and 58); these are. 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 Percival, John, 1863-1949. New York, H. Holt
Size: 1016px × 2458px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
