A companion to the United States pharmacopia; . 1084 A COMPANION TO THE tiation going on at several points in the interior, which finally coalescein such a manner that a ring of generating tissue (meristem) is formed,which divides the thickness of the root into two portions, an innerportion of parenchyma, which will afterward form the pith, and anouter zone which afterward forms the middle bark. These points de-velop into fibro-vascular bundles, structures which we find in all phanero-gamous or flowering plants, as well as in the acrogens, or that subdivisionof cryptogams in which there is fou
A companion to the United States pharmacopia; . 1084 A COMPANION TO THE tiation going on at several points in the interior, which finally coalescein such a manner that a ring of generating tissue (meristem) is formed,which divides the thickness of the root into two portions, an innerportion of parenchyma, which will afterward form the pith, and anouter zone which afterward forms the middle bark. These points de-velop into fibro-vascular bundles, structures which we find in all phanero-gamous or flowering plants, as well as in the acrogens, or that subdivisionof cryptogams in which there is found a distinct division of root, stem,. Fig. 618.—Transverse Section of Rose-twig, showing the Prickle. and leaf. In Fig. 619 B the fibro-vascular bundles (fv) are representedas somewhat more advanced in development. They are, however, con-nected by bands of generating tissue {secondary meristem—cb), whichare shown in Fig. 619 C, and which are capable of producing new fibro-vascular bundles. The fibro-vascular bundles are string-like masses of tissue pass-ing through the soft tissues, consisting mainly of prosenchyma andducts. Usually they are so intimately united with the parenchyma that theycannot be separated therefrom; but in some cases their string-like naturemay easily be shown, as in plantain (Plantago major) leaves or breaking the petiole or ribs of this leaf carefully, and pulling apart,little threadlike fibres, often several inches in length, may be drawn out, UNITED STATES PHARMACOPOEIA. 1085 and will be seen under the microscope to consist of spiral ducts and fusi-form cells. To examine the natur
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Keywords: ., bookcentury1800, bookdecade1880, bookpublishernewyo, bookyear1884
