. Plant anatomy from the standpoint of the development and functions of the tissues, and handbook of micro-technic. FIG. 12.—i, epidermis of oak leaf; 2,epidermis of Iris leaf, both viewed from thesurface; 3, group of cells from petal of Violatricolor; 4, two epidermal cells in cross sectionshowing thickened outer wall differentiatedinto three layers, namely, an outer cuticle,cutinized layer (shaded), and an innercellulose layer; 5 and 6, epidermal outgrowthsin the form of scales and hairs. (3 afterStrasburger, 4 after Sachs, and 5 after deBary.) DIFFERENTIATION OF THE TISSUES. \ are filled wi
. Plant anatomy from the standpoint of the development and functions of the tissues, and handbook of micro-technic. FIG. 12.—i, epidermis of oak leaf; 2,epidermis of Iris leaf, both viewed from thesurface; 3, group of cells from petal of Violatricolor; 4, two epidermal cells in cross sectionshowing thickened outer wall differentiatedinto three layers, namely, an outer cuticle,cutinized layer (shaded), and an innercellulose layer; 5 and 6, epidermal outgrowthsin the form of scales and hairs. (3 afterStrasburger, 4 after Sachs, and 5 after deBary.) DIFFERENTIATION OF THE TISSUES. \ are filled with cell-sap, largely water, and serve in many casesas an effective storehouse for water. This function is carriedto its fullest development where a multiple epidermis is producedby the tangential division of the protoderm, as in the rubberleaf (Fig. 13). In herbaceous plants, and in leaves generally and fleshy fruitsthe epidermis remains, but in the perennial parts of plants that increase in size from year to year, such asthe stems and roots of trees and shrubs, andin many underground parts that endure butfor a season, such as the Irish potato, corkis after a time produced beneath the epi-dermis and this dies and sloughs away. Primary Cortex.—All of the groundmeristem lying exterior to the procambiumstrands (which, it will be remembered laterbecome the primary vascular bundles)produces permanent tissues that are divisi- FIG. 13.—Cross section . .. of a portion of leaf of Ficus ble into two zones by a layer of cells, moreeiastka showing the mui- or less continuous,
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Keywords: ., boo, bookcentury1900, bookcollection, bookdecade1910, bookyear1910
