. An introduction to the structure and reproduction of plants. Plant anatomy; Plants. 15-2 SECRETORY CANALS { by the wind) leads to momentary distortion of the secretory space and consequent emission of part of the secretion. In the Mallows {Malva spp.) many parts of the plant contain irregular lysigenous cavities due to the confluence of cells with muci- laginous walls. In many plants, and especially in the stems and roots, the secretions are present in elongated structures, the secretory canals, which are generally schizogenous in origin, the bounding epithe- lium being developed through
. An introduction to the structure and reproduction of plants. Plant anatomy; Plants. 15-2 SECRETORY CANALS { by the wind) leads to momentary distortion of the secretory space and consequent emission of part of the secretion. In the Mallows {Malva spp.) many parts of the plant contain irregular lysigenous cavities due to the confluence of cells with muci- laginous walls. In many plants, and especially in the stems and roots, the secretions are present in elongated structures, the secretory canals, which are generally schizogenous in origin, the bounding epithe- lium being developed throughout their entire length. In cross-. FiG. 76.—Secretory organs. A, Lysigenous secretory cavity of the Clove (Eugenia caryophyllala). B, Schizogenous secretory^canal of the Ivy (Hedera helix) in transverse section. S,, secretory epithelium ; Sc., sclerenchyma sheath. sections these canals appear as rounded (Fig. 76, B) or oval cavities, whilst in longitudinal sections they are seen to be extensive sinuous tubes which frequently branch and fuse, thus forming a system often pervading all the parenchymatous tissues of the plant. The secretory canals are commonly [ leaf of the Scotch Fir, Pinits syhestris ; petiole of the Ivy) enveloped by a sheath of thick-walled ceUs (Fig. 76 B, Sc), which prevents compression or collapse through turgor of the surroundmg tissue. They often occur in the immediate neighbourhood of the phloem of the vascular bundles, as in the Ivy [Hedera helix) and the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Fritsch, Felix Eugene, 1879-; Salisbury, E. J. (Edward James), Sir, b. 1886. London, G. Bell and sons ltd.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpl, booksubjectplants
