. Introduction to structural and systematic botany, and vegetable physiology. Botany. 96 THE STEM. by elongation of the internodes. With the ensuing spring growth recommences, and anotlier set of internodes, and of nodes hearing ordinary leaves, foi-m the second year's growth, like the first; and so, by annual increments, a simple leafy stem is developed and carried up. Not only is the whole stem growing from year to year thus composed of a succession of similar growths, each the offspring of the preceding and the parent of the next, but also each annual growth itself consists of a lineal succ
. Introduction to structural and systematic botany, and vegetable physiology. Botany. 96 THE STEM. by elongation of the internodes. With the ensuing spring growth recommences, and anotlier set of internodes, and of nodes hearing ordinary leaves, foi-m the second year's growth, like the first; and so, by annual increments, a simple leafy stem is developed and carried up. Not only is the whole stem growing from year to year thus composed of a succession of similar growths, each the offspring of the preceding and the parent of the next, but also each annual growth itself consists of a lineal succession of similar parts, viz. of leaf- bearing joints of stem, developed each upon its predecessor, and in turn surmounted by the next in the series. These similar parts, which by their repetition make up the Phaenogamous plant, have been termed 163. Phytons (from the Greek (/lurdc, plant), or plant-elements. The first phyton is the radicle of the embryo, with its cotyledon or pair of cotyledons, from its base developing the root, from above expanding its leaf or pair of leaves (as already described in detail, 119- 122), and then giving birth to the next phyton, or joint of stem and leaf, and so on, in lineal succession. So that the whole herb, shrub, or tree, as to its upward growth, is a multiplica- tion of the simple plantlet it began with as it developed from the seed. Moreover, any joint of stem, when favorably situated for the pur- pose, may produce secondary roots (142), and thus complete the vegetable individuaUty, hav- ing all the organs of vegetation (116). 164. The repetition of these similar parts in '" the direct line, each from the summit of its pre- decessor, builds up a simple or main stem, to which many plants are restricted during the first year's growth, and some, such as Palms and Reeds, throughout their whole existence. Their production from new starting-points gives rise to branches. FIG. 157. Diagram of a simple-stemmed plant, lilte a Grass, and of t
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