. Text-book of botany, morphological and physiological. Botany. FIG. 284.—Diagram of the succession of cell-divisions in the apex of the root of Eqtiisetum hiemale (after Nageli and Leitgeb), (this diagram will serve also in the main for Ferns and for Marsilia). A longitudinal section ; B transverse section at the lower end of A ; h h h the primary walls, fu the sextant walls of the segments, indicated in A by the figs. I—XVI, k Int np the layers of the root-cap, all the further divisions being omitted; c c in the interior of the root indicates the walls by which the rudimentary fibro-vascular
. Text-book of botany, morphological and physiological. Botany. FIG. 284.—Diagram of the succession of cell-divisions in the apex of the root of Eqtiisetum hiemale (after Nageli and Leitgeb), (this diagram will serve also in the main for Ferns and for Marsilia). A longitudinal section ; B transverse section at the lower end of A ; h h h the primary walls, fu the sextant walls of the segments, indicated in A by the figs. I—XVI, k Int np the layers of the root-cap, all the further divisions being omitted; c c in the interior of the root indicates the walls by which the rudimentary fibro-vascular cylinder (procambium) is divided from the cortex of the root, e the boundary-wall between the epidermis 0 and the cortex (epidermal wall), r r boundary-wall between the outer and inner cortex (cortical wall), 1, 2, 3, the successive tangential walls by which the inner cortex is divided into several layers, the radial divisions being omitted. shoots or of those specially destined for this purpose. Above the last sterile leaf- sheath of the fertile axis an imperfectly developed leaf-sheath is first of all produced (Fig. 285, a), a structure corresponding in some degree to the bracts of Phanerogams. The development of this structure is sometimes more, sometimes less leaf-like ; foliar girdles are formed above it in acropetal succession beneath the growing end of the shoot, projecting however but slightly, as in the ordinary formation of leaves of Equisetum. A large number of protuberances project from each of these girdles, corresponding to the teeth of the ordinary leaf-sheaths; and thus several whorls of hemispherical projections are formed lying closely one over another, which, in- creasing more rapidly in size at their outer part, press against one another, and thus become hexagonal, the successive whorls alternating; while the basal (inner) 1 [See Van Tieghem, La Racine, Paris 1871.]. Please note that these images are extracted from scanned page images that may have been
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
