r.ROWTII OF TIIF. PLANT FHOMTIIK SEKD. [L1:SS0N2. 



opoil, in gi-rmiiiation ; when it liiid incnly to unfold and grow, — 

 to clonirate its riulinientary stem, wliich takes 

 at tiie .»anie time an upright position, so as to 

 bring the leaf-bearing end into the light and air, 

 where the two leaves expand ; while from the 

 (>ppo>ile end, now pushed farther downwards 

 into liie soil, the root begins to grow. All this 

 is true in tiie main of all plants that spring irom 

 real seeds, although with great diversity in the 

 partic'ulai-s. At least, there is hardly an excep- 

 tion to the fact, that the plantlet exists ready 

 formed in the seed, in some shape or other. 



16, The rudimentary plantlet contained in 

 the seed is called an Embryo. Its little stem 

 is named the Radicle, because it was sujjposed 

 to be the root, when the difference between the 

 root and stem was not so well known as now. 

 It were better to name it the Caulicle (i. e. 

 little stem) ; but it is not expedient to change 

 old luunes. The seed-leaves it beai's on its sum- 

 mit (here two in number) are technically called 

 Cotyledons. The little bud of undeveloped 

 leaves which is to be found between the co- 

 tyledons before germination in many cases (as in the Pea, Bean, 

 Fig. 17, &c.), has been named the Plumule. 



17. In the Maple (Fig. 4), as also in the Morning-Glory (Fig. 

 28), and the like, this bud, or plumule, is not seen for some days 

 after the seed-leaves are expanded. But soon it appears, in the 

 Maple as a pair of minute leaves (Fig. 5), erelong raised on a stalk 

 which carries them up to some distance above the cotyledons. The 

 plantlet (Fig. G) now consists, above ground, of two pairs of leaves, 

 viz.: l.the cotyledons or seed-leaves, borne on the sununit of the 

 original stemlet (the radicle) ; and 2. a pair of ordinary leaves, 

 raised on a second joint of stem which has grown from the top 

 of the first. Later, a third pair of leaves is formed, and raised 

 on a third joint of stem, proceeding from the summit of the second 

 (Fig. 7), just as that did from the first; and so on, until the germi- 

 nating plantlet becomes a tree. 



Flo. !). r.orniinnting Red Maple, which lias produced its root beneatli, and is developing 

 ^<c^ond pair uf leav«8 above. 6. Same, furtlier advanced. 



