122 



GERMINATION. 



bursting integument. A section of this seed would now show tlio folded 

 embryo impatient of confinement. 



Gormination of the Maple. 



475, Samara ; section showing thn folded cotyledons at c 

 476 — 480, Progieesivo stages. 



612. The PROCESS CONCLUDED. Soon the radicle has extended, and, 

 pale in color, has hidden itself in the bosom of the dark, damp earth. 

 481 4S2 Now the cotyledons, unfolding and grad- 



ually freed from the seed coats, display 

 themselves at length as a pair of green 

 leaves. Lastly the plumule appears in 

 open air, a green bud, already showing 

 a lengthening base, its first internode, 

 and soon a pair of regular leaves, lobed 

 as all maple leaves. The embryo is 

 BOW an embryo no longer, but a grow- 

 ing plant descending by ite lower axis, 

 ascending and expanding by its upper. 

 613. "What becomes of the cotyledons. 

 The germination of the tulip-treo, oak, pea, 

 squash, and other Dicotyledons may bo watched 

 with equal advantage, and the cliicf difference 

 observed among them will be in the disposal 

 of the cotyledons. In general, these arise with 

 the ascending axis, as in the maple and bean, 

 snd act as the first pair of leaves ; but some- 

 times, when they are very thick, as in the poa 

 buck-eye, oak (6—9), they remain as first 

 containing the cotyledon ; 'V, pilule™" P'^''^'^ ^'* "^^ coUum (§ 118), neither asccnd- 

 radlolo; «, rootlets (adventitious). mg nor dcscendmg. 



