18 



GROWTH OF THE PLANT FKOM THE SEED. [lESSOST 3. 



leaf, or a pair (rarely a circle) of leaves, — will have gained a cor- 

 rect idea of the plan of vegetation in general, and have laid a good 

 foundation for a knowledge of the whole structure and physiology 

 of plants. For the plant goes on to grow in the same 

 way throughout, by mere repetitions of what the early 

 germinating plantlet displays to view, — of what was 

 contained, in miniature or in rudiment, in the seed itself. 

 So far as vegetation is concerned (leaving out of view 

 for the present the flower and fruit), the full-grown leafy 

 herb or tree, of whatever size, has nothing, and does 

 nothing, which the seedling plantlet does not have and' 

 do. The whole mass of stem or trunk and foliagfe of 

 the complete plant, even of the largest forest-tree, is 

 composed of a succession or multiplication of similar 

 parts, — one arising from the summit of another, — 

 each, so to say, the offspring of the preceding and 

 the parent of the next. 



So. In the same way that the earliest portions of 

 the seedling stem, with the leaves 

 they bear, are successively produced, 

 so, joint by joint in direct succes- 

 sion, a single, simpl», leafy stem is 

 developed and carried up. Of such a 

 simple leafy stem many a plant consists 

 (before flowering, at least), — many 

 herbs, such as Sugar-Cane, Indian 

 Corn, the Lily, the tall Banana, the 

 Yucca, &c. ; and among trees the 

 , 44 Palms and the Cycas (wrongly called 



Sago Palm) exhibit the same simplicity, their 

 stems, of whatever age, being unbranched columns 

 (Fig. 47). (Growth in diameter is of course to be considered, 

 as well as growth in length. That, and the question how growth 

 of any kind takes place, we will consider hereafter.) But more 

 commonly, as soon as the plant has produced a main stem of a cer- 

 tain length, and displayed a certain amount of foliage, it begins to 



FIG. 43. Section of a seed of tho Iris, or Flower-de-Luco, showing its small embryo in 



the albumen, near the bottom, 

 FIG, 44, Germinating plantlet of the Iris, ^ 



FIG. 45. Section of a seed of a Pine, with its embryo of several cotyledons, 46. Early 



needling Pine, with its stemlet, displaying its^ix seed-leaves. 



