. Text-book of botany, morphological and physiological. Botany. FIG. 404.—Diagrammatic representation of the formation of the primary root in Monocotyledons and its connection with the stem (after Hanstein); v sus- pensor, h hypophysis, -w w line of separation of the root and stem, 7vk layer of the root-cap, d dermatogen, pb periblem, pi plerome. FIG. 405. — Diagrammatic representation of the same in the case of Dicotyledons (after Hanstein); 1, 2, the first layers of the root-cap, p periblem, d derma- togen, pi plerome. found in several plants to harmonise with this. In Trapa natans, for exam
. Text-book of botany, morphological and physiological. Botany. FIG. 404.—Diagrammatic representation of the formation of the primary root in Monocotyledons and its connection with the stem (after Hanstein); v sus- pensor, h hypophysis, -w w line of separation of the root and stem, 7vk layer of the root-cap, d dermatogen, pb periblem, pi plerome. FIG. 405. — Diagrammatic representation of the same in the case of Dicotyledons (after Hanstein); 1, 2, the first layers of the root-cap, p periblem, d derma- togen, pi plerome. found in several plants to harmonise with this. In Trapa natans, for example, it is as follows:—A group of cells of the pericambium, which consists of only one layer, divides radially; the newly-formed cells elongate in the same direction, and then divide tangentially; the outer of the two layers produces the dermatogen, the inner the body of the root. The dermatogen, pushed outwards by the development of the body of the root, produces the root-cap in the way already mentioned; the tissue of the body of the root itself which is covered by it becomes differentiated into plerome and periblem. The same process takes place in Pistia, and probably also in Grasses. Hanstein and Reinke do not- find ' anywhere an apical cell which ori- ginates the growth, as in Cryptogams, but a group of cells which obey a common law of growth.' The variation in the size of the embryo in the ripe seed of Angiosperms has 1 [See the account of the apical growths of roots and of the development of lateral roots which is given in the Appendix.] 2 Compare what was said on Fig. 125, p. 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 Sachs, Julius, 1832-1897; Vines, Sydney Howard, 1849-1934. ed. and tr. Oxford, Clarendon press
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
