94 BOTANY FOR BEGINNERS. [Ch. XV. 
very simple, consisting of a uniform substance enclosed in its 
appropriate bark or skin. When the vital principle is excited 
to action, vessels are formed, and parts developed, which seeni- 
ed not previously to have existed. The embryo is usually 
central, and enclosed by the ectyledons; sometimes it is no 
more than a mere point or dot, and in some cases, altogether 
invisible to the naked eye. The embryo consists of two parts. 
389. Ist. The Plume, is the ascending part, which unfolds 
‘tself into herbage. 
Fig. 65. 390. 2d. The Radicle is the descend- 
Fg ing part, which unfolds itself into roots. 
At Fig. 65 appears the embryo in a ger- 
»  minating state; a represents the radicle, 
My, 5 the plume, c the cord by which the plant 
i is still connected with the cotyledons, 
fi] and receives from them its nourishment. 
i DS ; To use the words of an ancient bota- 
Ze Null ) nist, “the embryo continzes imprisoned 
A I ui within its seed, and remxtas in a pro- 
|” found sleep, until awakened xy germina- 
{ tion; it meets the light and air to grow 
into a plant, similar to its parent.” 
There are various appendages which 
may, or may not, be present without in- 
vary to the structure of the seed. 
391. Aigrette, or egret, sometimes called pappus, is a kind 
of feathery crown with which many of the compound flowers 
are furnished, evidently for the purpose of disseminating the 
_seed to a considerable distance by means of winds; as the dan- 
delion. The egret includes all that remains on the top of the 
seed after the corolla is removed. 
392. Stipe is a thread connecting the egret with the seed. 
The egret is said to be sessile when it has no stipe, simpla 
when it consists of a bundle of hairs without branches, plumose 
when each hair has other little hairs arranged along its sides, 
like the beards on a feather. ; 
ees per rene 
389. Describe the plume. ‘ 
390. Describe the radicle. 
391. What is the egret 2 
392, What is the stype ? 
