Pharmaceutical Archives Volume 3

Pharmaceutical Archives Volume 3

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1900 edition. Excerpt: ...the resin reservoirs. In sections taken through regions showing the transition toward the pithless type, an increase in the degree of lignification of the central parenchyma is seen. The fundamental tissues of this root are so closely packed with starch (Fig. 4) in all cases examined that cell walls are with difliculty made out. This necessitates the clearing of the tissues by the use of caustic potash solution. The starch grains are spheroidal or ovoidal in shape when simple, usually showing a central or nearly central hilum. In the larger grains, distinct fissures are to be seen, often of unusual dimensions. Layers are hardly discernible without special treatment. Very often the grains are aggregated, forming compounds of two, three or four parts. They are united along their flattened sides, and form two-, three-or four-lobed aggregations (Fig. 4). The fibro-vascular bundles (Fig. 5) offer some difliculties when studied in commercial material. The phloem regions, especially, become so compressed and distorted as well nigh to balk the student. An endeavor was made to get alcoholic material but without success. The phloem, seen in cross section, forms a sharply limited group of elements capping the wood wedge exteriorly (Figs. 1 & 2). The xylem areas are much more readily made out. They consist of a rather dense tissue in which large tracheae are scattered about, usually singly, less often in groups of two or three. Seen in longitudinal sections, they are heavily pitted and belong to the reticulated type of vessel. Frequently these vessels-are more or less filled with masses of yellowish resin. The ground work of the wood bundle is made up in part of closely packed, heavily thickened and pitted wood fibres, terminated by tapering...show more

Product details

  • Paperback | 78 pages
  • 189 x 246 x 4mm | 154g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236973801
  • 9781236973801