LESSON 3.] GROWTH OF THE PLANT FEOM THE SEED. 



17 



self, and should do so, by examining grains of Indian Corn, soaked 

 in water, before and also during germination. In the Onion, Lily, 

 and the Iris (Fig. 43), the monocotyledonous embryo is simpler,' 

 consisting apparently of a simple oblong 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 has wrapped up in it a minute jplumide, 

 or bud, that shows itself when the seeds sprout in germi- 

 nation. The first leaf which appears above ground in all 

 these cases is not the cotyledon. In all seeds with one coty- 

 ledon to the embryo, this remains in the seed, or at least 

 its upper part, while its lengthening base comes out, so as 

 to extricate the plumule, which shoots upward^ and de- 

 velops the first leaves of the plantlet. These appear one 

 above or within the other in succes- 

 sion, — as is shown in Fig. 42 and 

 Fig. 44, — the first commonly in the 

 form of a little scale or imperfect 

 leaf; the second or third and the " 



following ones as the real, ordinary leaves of 

 the plant. Meanwhile, from the root end of 

 the embryo, a root (Fig. 41, 44), or soon a 

 whole cluster of roots (Fig. 42), makes its 

 appearance. 



33. In Pines, and the like, the embryo con- 

 sists of a radicle or stemlet, bearing on its 

 summit three or four, or often from five to 

 ten slender cotyledons, arranged in a 

 circle (Fig. 45), and expanding at 

 once into a circle of as many green 

 leaves in germination (Fig. 46). Such . 

 embryos are said to he polycotyledonotts, 

 that is, as the word denotes, many- 

 cotyledoned. 



34. Plan of Vegetation. The student 



who has understandingly followed the 

 growth of the embryo in the seed into the seedling plantlet, — com- 

 posed of a root, and a stem of two or three joints, each bearing a 



FIG. 4L Grain of Indian Com in germination. 

 FIG, 43. The same, furtlier advanced^ ^ 



