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 the similar parts, or 

 phytons, a to g, of which it is composed. 



