. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. Fig. 228. FIG. 227.—Phytocrene spec. Transverse section of the stem, X 2. from the same material as that described by Met- tenius ; /; the eight protrusions of the porous wood ; * the bast-plates between them. Laterally from one of them, and to the right of the wood-protrusion marked A, are two small similar ones. Parenchyma of pith and are left white. Ex- ternally to the inner circle of growth is one of renewed growth, which shows several bundles, between broad parenchy- mat
. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. Fig. 228. FIG. 227.—Phytocrene spec. Transverse section of the stem, X 2. from the same material as that described by Met- tenius ; /; the eight protrusions of the porous wood ; * the bast-plates between them. Laterally from one of them, and to the right of the wood-protrusion marked A, are two small similar ones. Parenchyma of pith and are left white. Ex- ternally to the inner circle of growth is one of renewed growth, which shows several bundles, between broad parenchy- matous medullary rays, opposite each of the inner protrusions of wood ; these consist of a relatively large xylem, con- structed similarly to the latter, and an extremely small bast portion ; and opposite each of the inner bast-plates is one bundle, oral most two to three, constructed like the latter, which have only a very small xylem at their inner side. The latter could hardly be indicated in the Hig. Fig. 228.—Portion of a bast-plate from Fig 227 (X about 140); s—s sieve-tubes. The narrow meshes of simple contour abuttmg on these are transverse sections of the cambiform cells ; the elements with a strong double contour are bast fibres. the almost chess-board-like appearance of the plates; at the outermost oldest parts of them the arrangement is less regular, the sclerotic elements are in larger proportion. A multiseriate broad medullary ray, consisting of very delicate cells, limits each lateral face of the bast-plate, and is continuous towards the pith along-side of the superseded band of wood. It appears, as in the Bignonias, to consist in not very young specimens of two radial portions, which undergo displacement. There are at least indica- tions of a step-like external widening of the bast-plates. Externally from the zone of cambium surrounding the protrusions of wood, that is in the normally arranged layer of bast, there are scattered irregularly, here and there, sm
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Keywords: ., bookcentury1800, bookdecad, booksubjectplantanatomy, bookyear1884
