. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. IDIOBLASTS. 97 KECEPTACLES FOR SECRETIONS. 292. Individual cells (idioblasts) may differ greatly from their neiglibors as respects tlieir contents. Sucli cells may be well named after their characteristic contents ; as ciystal-cells, resin- cells, raucilage-celis, tannin-cells, etc. 293. They vary much in shape and size. Frequently they are not readil3- distinguishable from their immediate neighbors by anything except their contents. In other cases, however, t
. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. IDIOBLASTS. 97 KECEPTACLES FOR SECRETIONS. 292. Individual cells (idioblasts) may differ greatly from their neiglibors as respects tlieir contents. Sucli cells may be well named after their characteristic contents ; as ciystal-cells, resin- cells, raucilage-celis, tannin-cells, etc. 293. They vary much in shape and size. Frequently they are not readil3- distinguishable from their immediate neighbors by anything except their contents. In other cases, however, they may assume forms widely different from those of the cells around them, and may also be distinguished bv their size. Tliej' are often so associated togetlier as to form " ; 294. (Jrystal-celh. These sometimes, as de Bary points out, curiously resemble the shape of the crystal or groups of crystals. 78 â which they contain. Thus globular clusters are generally con- tained in spherical cells, elongated prisms in elongated cells (as in Quillaja). "In many trees each cambium-cell (as it develops into a bast-fibre) maj-be divided by diagonal partitions into numerous (20 to 30) chambers, the height of which is about the same as the width, and each is filled hy a crystal or a small cluster. In this case the general outline of the original cambium- cell remains unaltered, and the whole row of compartments may be isolated as a chambered ;* The bast-cells containing crystals have been already noticed. 295. Resin-cells. In a large number of plants soft viscid substances are present, which exude when the tissues are wounded. Thej' may be ronghlj- classed into (1) JBalsams, in which resinous matter is mixed with a considerable proportion of 1 De Bary : Vergleichende Anatomie, p. 145. Fig. 78. Crystal-cells: a, from the petiole of Begonia manicata; ft, a cell with raph- ides, from Lemna trisulca; c, from Phallus caninus. (Kny.). Please note that these i
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