. South African botany. Botany. THE STEM 55 As the oak-tree becomes older there is a more com- plex formation of cork, which leads to the rough scaly appearance of the bark characteristic of full-grown trees. 31. Lenticels.—When cork has been formed round a stem the stomata of the stem are useless, for cork being impermeable to cell-sap all the cortex outside it dies. To replace these stomata new organs are formed. Fig. 36.—Cork Layer of Beech. e. Cuticle, e. Epidermis, p. Cork. ph. Phellogen. col. CoUenchyma of cortex, cor. Cortex. (From Darwin's " Elements of Botany ".) in older st
. South African botany. Botany. THE STEM 55 As the oak-tree becomes older there is a more com- plex formation of cork, which leads to the rough scaly appearance of the bark characteristic of full-grown trees. 31. Lenticels.—When cork has been formed round a stem the stomata of the stem are useless, for cork being impermeable to cell-sap all the cortex outside it dies. To replace these stomata new organs are formed. Fig. 36.—Cork Layer of Beech. e. Cuticle, e. Epidermis, p. Cork. ph. Phellogen. col. CoUenchyma of cortex, cor. Cortex. (From Darwin's " Elements of Botany ".) in older stems called Lenticels (fig. 37). Underneath the stomata a meristematic tissue arises called the cam- bium of the lenticel, which gives rise on the outside to a number of cells with numerous air spaces between them called the Complementary Cells of the lenticel, and on the inside to secondary cortex. The activity of this meristematic tissue soon causes the epidermis to be ruptured, and thus air can pass freely in and out 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 Storey, Francis W; Wright, K. London, New York, Longmans, Green
Size: 1503px × 1662px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1922
