LESSON 3.] GUOWTII OF THK PLANT ^OM THE SEED. 



11 



the same thing on a small<'r scale. The embryo, whicli liere also 

 tJiukes u|) the whole hulk of the kernel of the 

 seed, diflers from that of the Pumpkin only 

 in having the seed-leaves more thickened, hy 

 the much larger quantity of nourishment stored 

 up in their tissue, — so large and so pure in- 

 deed, that the almond becomes an article of 

 food. Fed by this abundant supply, the second, 

 and even the third joints of the stem, with 

 their leaves, shoot forth as soon as the stemlet comes to the surface ol 

 the soil. The Beech-nut (Fig. 13), with 

 its sweet and eatable kernel, consisting 

 mainly of a pair of seed-leaves folded 

 together, and gorged with nourishing 

 matter, offers another instance of the 

 same sort : this ample store to feed 

 upon enables the germinating plantlet 

 to grow with remarkal^le vigor, and to 

 develop a second joint of stem, with its 

 pair of leaves (Fig. 14), before the first 

 pair has expanded or the root has ob- 

 tained much foothold in the soil. 



28. A Bean aflurds a similar and 

 more familiar illustration. Here the co- 

 tyledons in the seed (Fig. IG) are so 

 thick, that, although they are raised out 

 of ground in the ordinary way in ger- 

 mination (Fig. 17), and turn greenish, 

 yet they never succeed in becoming leaf- 

 like, — never display their real nature of 

 leaves, as they do so plaiidy in the Ma- 

 ple (Fig. o),tlie Pumpkin (Fig. 10), the 

 Morning-Glory (Fig. 8, 26-28), &c.^ 

 Turned to great account as magazines 

 of food for the germinating plantlet, they 

 fulfil this special office admirably, but 



FK;. II. An A|)|ilo-Boo(l cm ihm.ipli Ipiiciiiwisp, Kliowinc «l"o cniliryo wiili its thickened 

 eotylodi.iis. IJ. Tlic piiibryo «>t the Applf, t.ikiii out whule, \ts cotylfiloiiH |iarlly seimrated 



Flu. 13. A Hecch-iiiit, cut arniss. H. lli-ciiiiiiiij! mriiiiiintum ol the Ik-iTh, shiiwiiii; iha 

 pliiniiilu gmwiiic \tiUiTv the cnlyleiliiiis liavo «>|k'iu<I or iho ruot has scarcely furiiicd 15. Tlw 

 •ainc, a littio later, with the bccoiii] juiiil loiiulheiicd. 



