332 



HOW CEOPS GROW. 



young plant as it develops from the embryo, before it is 

 capable of depending on the soil and atmosphere for sus- 

 tenance. It is not, however, an indispensable part of the 

 seed, and may be entirely removed from it, without 

 thereby preventing the growth of a new plant. 



The Embryo, or Germ, is the essential and most 

 important portion of the seed. It is, in fact, a ready- 

 formed plant in miuiatui-e, and has its root, stem, leaves, 

 and a bud, although these organs are often as undevel- 

 oped in form as they are in size. 



As above mentioned, the chit of the seeds of maize and 

 the other grains is the embryo. Its form is with diffi- 

 culty distinguishable in the dry seeds, but when they 

 have been soaked for several days in water, it is readily 

 removed from the accompanying endosperm, and plainly 

 exhibits its three parts, viz., the Radicle, the Flumule, 

 and the Cotyledon. 



In Fig. 63 is represented the embryo of maize. In A 

 and B it is seen in section imbedded in the endosperm. 

 C exhibits the detached embryo. The Radicle, r, is the 

 stem of the seed-plant, its lower extremity is the point 

 from which downward growth proceeds, and from which 

 the first true roots are produced. The Plumule, c, is 

 the central bud, out of which the stem, with new leaves, 

 flowers, etc., is developed. The Cotyledon, T>, is in 

 structure a ready-formed leaf, which clasps the plumule 

 in the embryo, as the 

 proper leaves clasp the 

 stem in the mature 

 maize-plant. The coty- 

 ledon of taaize does not, 

 however, perform the 

 functions of a leaf ; on 

 the contrary, it remains in the soil during the act of 

 sprouting, and its contents, like those of the endosperm, 

 are absorbed by the seedling. The first leaves which ap- 



Flg.6S. 



