. Elements of botany. Plants. 110 ELEMENTS OF BOTANY. later, but it will make matters simi)ler to state at once that the epidermis serves as a mechanical protection to the parts beneath and prevents excessive evaporation, that the palisade cells (which it may not be easy to make out very clearly in a roughly prepared section) help to prevent too rapid evapora- tion of sap from the leaf when exposed to excessive dryness, heat, and direct sunlight, and that they hold large quantities of the green coloring-matter of the leaf in a position where it. Ji Fig. 97.—Epidermis of Leaf of Althaea. (Much
. Elements of botany. Plants. 110 ELEMENTS OF BOTANY. later, but it will make matters simi)ler to state at once that the epidermis serves as a mechanical protection to the parts beneath and prevents excessive evaporation, that the palisade cells (which it may not be easy to make out very clearly in a roughly prepared section) help to prevent too rapid evapora- tion of sap from the leaf when exposed to excessive dryness, heat, and direct sunlight, and that they hold large quantities of the green coloring-matter of the leaf in a position where it. Ji Fig. 97.—Epidermis of Leaf of Althaea. (Much magnified.) I, from upper surface ; 11, from lower surface ; h, star-shaped compound hairs ; st, stomata; />, upper ends of palisade cells, seen through the epidermis. can receive enough, but not too much sunlight. The stomata admit air to the interior of the leaf (where the air-spaces serve to store and to distribute it) and, above all, they regulate the evaporation of water from the plant. 137. Leaf of " India-Ruhber Plant.'' i — Study with the microscope, as the lily leaf was studied, make the same set of sketches, note the differences in structure between the two leaves, and try to make out their meaning. ' Firus 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Bergen, Joseph Y. (Joseph Young), 1851-1917. Bergen's Botany: key and flora, Pacific coast ed. Boston : Ginn
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
