10 



GROWTH OF THE PLANT FROM THK SEED. [lESSON 3. 



the tiny j)lant is alrrady able to shift for itself; — that is, to hve and 

 conlinut' its growtli on what it now takes from the soil and from the 

 air, and elaborates into iioun'sfiinent in its two green leaves, under 

 the influenee of the light of the sun. 



25. In most ordinary phmts, a larger portion of nourish;jient is 

 provided beforehand in the seed ; and the plantlet consequently is 

 not so early or so entirely left to its own resources. Let us examine 

 a number of cases, selected from very common plants. Sometimes, 

 as has just been stated, we find this 



26. Deposit of Food in the Embryo itself. And we may observe it 

 in every gradation as to quantity, from the Maple of our first illus- 



_ tration, where there is very little, up to 

 the Pea and the Horsechestnut, where 

 there is as much as there possibly can 

 be. If we strip off the coats from the 

 large and flat seed of a Squash or 

 Pumpkin, we find nothing but the em- 

 bryo within (Fig. 9) ; and almost the 

 whole bulk of this consists of the two 

 seed-leaves. That these contain a good 

 supply of nourishing matter, is evident 

 from their sweet taste and from their 

 thickness, although there is not enough 

 to obscure their leaf-like appearance. 

 It is by feeding on this supply of nour- 

 ishment that the germinating Squash or 

 Pumpkin (Fig. 10) grows so rapidly 

 and so vigorously from the seed, — 

 lengthening its stemlet to more than 

 twenty times the length it had in the 

 seed, and thickening it in proportion, — 

 sending out at once a number of roots 

 from its lower end, and soon developing 

 the plumule (16) from its upper end into a third leaf: meanwhile 

 the two cotyledons, relieved from the nourishment with which their 

 tissue was gorged, have expanded into useful green leaves. 



27. F'or a stronger instance, take next the seed of a Plum or 

 Peach, or an Almond, or an Apple-seed (Fig. 11, 12), which shows 



FIO. 0. Embryo of a Pumpkin, of the natural sizo ; the cotyledons a little opened 

 JO. The aaiiie, when it lias germinated- 



