The Encyclopaedia Britannica; .. A dictionary of arts, sciences and general literature . ents which have given origin to the name cinen-chyma applied to laticiferous tissue by some movements, classed under the name cyclosis, mustnot be confounded with the motion of protoplasm in cellswhich is designated rotation. We have seen that the cellular tissue is sometimes in-complete, that is, the cells do not touch on every side (fig. 9).The intervening spaces are called intercelhdar spaces, andthese may-be either circumscribed cavities called lacunae,or they may extend for some length t
The Encyclopaedia Britannica; .. A dictionary of arts, sciences and general literature . ents which have given origin to the name cinen-chyma applied to laticiferous tissue by some movements, classed under the name cyclosis, mustnot be confounded with the motion of protoplasm in cellswhich is designated rotation. We have seen that the cellular tissue is sometimes in-complete, that is, the cells do not touch on every side (fig. 9).The intervening spaces are called intercelhdar spaces, andthese may-be either circumscribed cavities called lacunae,or they may extend for some length through the tissue aaintercelhdar canals ; but these two structures pass into oneanother. In the earliest stage of development the tissueis always complete, and these spaces are formed subse-quently by a splitting of the partition or common wall ofthe cells, and they may subsequently be increased in size byan absorption of the investing cells. These lacunas and canalsmay contain air, especially in aquatic plants, to give thembuoyancy, as in Potamogeton (fig. 26), or they may be recep-. Fig. 20. Vei-ticaJ section of the leaf of Potamogeton or Pondweed, showing air carltlei %tlacunaa f, and parenchyinatous cells j?, vrith granules, tacles for various secretions, and when they exist as canalsthey usually aid in conducting sap. The intercellular canalsare exceedingly well seen in coniferous plants, where theyconstitute resin passages, forming a continuous systemthroughout the plant, and arranged at intervals in concentriccircles in the xylem or wood portion of the stem. Chlorophyll is the green colouring-matter of plants. Itoccurs in the cells of the superficial parts of plants unitedwith small portions of the protoplasm (chlorophyll bodies),which are combined into grains of various forms. Starch-grains are usually abundant in the chlorophyll is soluble in alcohol and ether. It consists offour substances, two yellow and two green, which possessdistinct optical pro
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