. Botany for secondary schools; a guide to the knowledge of the vegetation of the neighborhood. Plants. THE GROWING POINT 279 leaves the elaboration of plant-food takes place. Intercellular spaces filled with air and other gases are common in this tissue of leaves, as well as in parenchyma of other parts of the plant. 473. To study growing points use the hypocotyl of Indian corn. Prepared slides may be secured having stained longi- tudinal sections of the hypocotyl. The median section should be studied with the high power. Note these points (Fig. 448): (a) Root-cap beyond the grow- ing point,
. Botany for secondary schools; a guide to the knowledge of the vegetation of the neighborhood. Plants. THE GROWING POINT 279 leaves the elaboration of plant-food takes place. Intercellular spaces filled with air and other gases are common in this tissue of leaves, as well as in parenchyma of other parts of the plant. 473. To study growing points use the hypocotyl of Indian corn. Prepared slides may be secured having stained longi- tudinal sections of the hypocotyl. The median section should be studied with the high power. Note these points (Fig. 448): (a) Root-cap beyond the grow- ing point, (b) The shape of the end of the root proper and the shape of the cells found there, (c) The group of cells in the middle of the first layers beenath the root-cap. This group is the growing point, (d) Study the slight differences in the tissues a short distance back of the growing point. There are four regions: the plerome, several rows of cells in the center; the endodermis, composed of a single layer on each side; the peri- blem, of several layers outside the endodermis; the dermatogen, on the 448 Growing point of root of a ' Indian corn: a, cl, dermatO- outer edges. Make a drawing of the ^n-, P, Pl peribiem; e, e, en- ,â Tr ⢠e ii dodermis; pl, ;; i, in- section. It a series ot the cross-sec- itiai group of ceils, or growing tions of the hypocotyl should be made point proper; c' root-cap- and studied, beginning near the growing point and running back some distance, it would be found that these four tissues become more distinctly marked. The central cylinder of plerome will contain the ducts and vessels; the endodermis remains as endodermis; peribiem becomes the cortex of parenchyma; the dermatogen becomes the epidermis of the root. 474. Epidermal Tissue is a special modification of parenchyma, comprising the thin layers on the exterior ot. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectplants, bookyear1913
