59, 60.] THE SEED. 71 



179. The albumen or endosperm is a starchy or 

 farinaceous substance accompanying the embryo and 

 serving as its first nourishment in germination. Its 

 qualities are wholesome and nutritious, even in poison- 

 ous plants. Its quantity, when compared with the 

 embryo, varies in every possible degree ; being ex- 

 cessive (Ranunculacese), or about equal (Violaceae), or 

 scanty (Convolvulaceae), or none at all (Leguminosae). 

 In texture it is mealy in Wheat, mucilaginous in 

 Mallows, oily in Ricinus, horny in Coffee, ruminated 

 in Nutmeg and v Papaw, ivory-like in the Ivory-palm, 

 fibrous in Cocoanut, where it is also hollow, inclosing 

 the milk. 



180. The embryo is an organized body, the rudi- 

 ment of the future plant, consisting of root (radicle), 

 stem-bud (plumule), and leaves (cotyledons). But these 

 parts are sometimes quite indistinguishable until ger- 

 mination, as in the Orchis tribe. The Radicle is the 

 descending part of the embryo, always pointing toward 

 the micropyle, the true vertex of the seed. The Plu- 

 mule is the germ of the ascending axis, the terminal 

 bud, located between or at the base of the Cotyledons. 

 These are the seed-lobes, the bulky farinaceous part of 

 the embryo, destined to become the first or seminal 

 leaves of the young plant. The nutritive matter de- 

 posited in the seed for the early sustenance of the 

 germinating embryo, is found more abundant in the 

 cotyledons in proportion as there is less of it in the 

 albumen often wholly in the albumen (Wheat), again 

 all absorbed in the bulky cotyledons (Squash). 



181. The number of the cotyledons is variable; 

 and upon this circumstance is founded the most im- 

 portant subdivision of the Flowering Plants. THE 



