HOW PLANTS GROW FKOM THE SEED. 



13 



mbryo imbibes and feeds on as it sprouts. That the meal or starch of the grain 

 i actually changed into sugar at this time is clearly shown by malting, which is 

 lerely causing heaps of grain to sprout a little, and then destroying the life of 

 he embryo by dry heat ; when the grain (ngw^malt) is found to be sweet, and 

 contain much sugar. /^ ' - ^ '" 



36. The nourisliment which we mother-plant provides in the seed is not always 

 tored up outside of the embryo. In many cases it is deposited in the embryo 

 Iself, most commonly in the Feed-leaves. Then the seed consists of nothing but 

 he embryo within its coats. Maple-seeds are of this sort. Fig. 24 represents a 

 seed of Red Maple in the lower part of the winged seed- 

 vessel, which is cut away so as to sliow it in its place. Fig. 

 25 is the seed a little magnified, and with the coats cut away, 

 bringing to view its embryo coiled up within and filling the 

 seed completely. Fig. 26 is the embryo taken out, and a 

 little unfolded ; below is the radicle or stemlet ; above are the 

 two seed-leaves partly crumpled together. 

 Fig. 27 is the embryo when it has straight- 

 ened itself out, thrown off the seed-coats, 

 and begun to grow. Here the seed-leaves 

 are rather thick when they first unfold ; this 

 is on account of the nouri>hing matter which 

 was contained in their fabric, and which is 

 used mainly for the earliest growth of the 

 radicle or stemlet, and for the root formed 

 at its lower end, as we see in the next fig- 

 a, the radicle or stemlet of the embryo ; h, h, the two seed-leaves ; 

 By this time the little stock of nourishment is exhausted. But the 

 ilant, having already a root in the soil and a pair of leaves in the air, is able to 

 hift for itself, to take in air, water, &c., and by the aid of sunshine on its foliage 

 make the nourishment for its future growth. In a week or two it will have 

 nade enough to enable the next step to be taken. Then a little bud ajjpears at 

 he upper end of the stemlet, between the two seed-leaves, and soon it shows 

 he rudiments of a new pair of leaves (Fig. 28, d) ; a new joint of stem forms to 

 upport them (Fig. 29) ; this lengthens just as the stemlet of the embryo did, and 

 o the plantlet gets a second pair of leaves, raised on a second joint of stem 



ire (Fig. 28 

 , the root). 



