each from the summit of its predecessor; and 

 each joint elongates throughout every part, 

 until it reaches its full length. The root is not com- 

 posed of joints, and it lengthens only at the end, 



So the seedling plantlet finds itself provided with 

 all the organs of vegetation that even the oldest 

 plant possesses namely, root, stem, and leaves; and 

 has these placed in the situation where each is to 

 act the root in the soil, the foliage in the light and 

 air. Thus established, the plantlet has only to set 

 about its proper work. 



THE KINDS OF EMBRYO AS TO THE NUMBER OF 

 COTYLEDONS The embryo heretofore spoken of con- 

 sists of a radicle or stemlet, with a pair of cotyle- 

 dons on its summit. Botanists therefore call it 

 dicotyledonous an inconveniently long word to ex- 

 press the fact that the embryo has two cotyledons 

 or seed-leaves 



In many plants, however, the embryo has only 

 one cotyledon, and it is therefore .termed by the 

 botanists monocotyledonous an extremely long word, 

 like the other, of Greek derivation, which means 

 one-cotyledoned. The rudiments of one or more other 

 leaves are, indeed, commonly present in this sort of 

 embryo, as is plain to see in Indian corn, but they 

 form a bud situated above or within the cotyledon, 

 and enclosed by it more or less completely, so that 

 they evidently belong to the plumule; and these 

 leaves appear in the seedling plantlet, each from 

 within its predecessor, and therefore originating 

 higher up on the forming stem. 



The monocotyledonous embryo is simpler than 

 the former, consisting apparently of a simple ob- 

 long or cylindrical body, in which no distinction of 

 parts is visible; the lower end is radicle, and from 

 it grows the root; the rest is a cotyledon, which 



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