. A botanical note-book for the use of students of practical botany [microform]. Botany; Plants; Botanique; Plantes. A.\ALVTICALLy ARRaXGEP AM) EM' 23 (c) Medullary Rays, radiating lines of cellrlar tissue extending from the pith to the bark, and serving to keep up the communication between them (Fig. 195, A e;. (d) Bark, a circle surrounding the wood, consisting of the inner bark of bast tissue, and outer bark of cellular tissue (Fig. 195, A d). (e) Epidermis, the skin surrounding the whole. Cambium Loyer, a layer of soft, newly formed cells, between the wood and the bark. The growth
. A botanical note-book for the use of students of practical botany [microform]. Botany; Plants; Botanique; Plantes. A.\ALVTICALLy ARRaXGEP AM) EM' 23 (c) Medullary Rays, radiating lines of cellrlar tissue extending from the pith to the bark, and serving to keep up the communication between them (Fig. 195, A e;. (d) Bark, a circle surrounding the wood, consisting of the inner bark of bast tissue, and outer bark of cellular tissue (Fig. 195, A d). (e) Epidermis, the skin surrounding the whole. Cambium Loyer, a layer of soft, newly formed cells, between the wood and the bark. The growth of the stem takes place in this layer. 2. Of -The endogenous stem consists of bundles of woody and vascular tissue in the form of fibers (Fig. 196, A c and f), embedded in cellular tissue. The whole is surrounded by an integument which differs from a true bark in that it does not increase in layers and is not separate from the wood. The growth con- sists in the increase in the number of woody bundles, which spring from the base of new leaves and descend obliquely to the centre of the stem, then, curving out- ward, usually terminate in the circumference. 1 Root.—The root is constructed on the same general \Aan as the stem. The distinction between exogens and endogens is not so marked. The fibro-vascular tissue of exogens is seldom arranged in distinct concentric rings. There is no distinct pith, and there are no stomata in the epidermis. It develops no buds or leaves. The extremities of the roots and rootlets are tipped with a root-cap of dead cells (Fig. 197, a), which serves to protect the growing part of the root as it pushes its way through the earth. The growth of the root takes place just behind this root-cap (Fig. 197, b). Leaf.—The tissue of the framework belongs to the fibro- vascular system, while that of the remainder of the leaf consists of thin-walled cells of parenchyma, containing grains of chlorophyll. The stratum forming the upper surface of horiz
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectplants, bookyear18
