118 



TBE SEED. 



6 ST. The position op the seed in the pericarp is, 

 like that of the ovule, erect, ascending, pendulovs, etc. 

 (§ 534). Likewise in respect to its inversions, it is ortho- 

 tropous, andtropous, ampliltropous, and campyldtropom 

 {§ 536), terms already defined. The anatropous is by 

 far the most common condition. 



588. The hilum is tl^cscar. or mark left in 



the testa of the seed by its separation from the 



funiculus. It is com- 



monly called the eye, as 

 in the bean. In ortho- 

 tropous and campylo- 

 tropous seeds, the hilum 

 corresponds with the 

 chalaza (§535). In other 

 conditions it does not, 

 465 464 463 461 460 462 and the raphe (§537) cx- 



460, Aril of Eaonymvis. 461, Aril of Nutmeg (mace). 462, tgjjds between the twO 

 SeedofPoIygala, embryo, carimcle, c, (too small.) 463, Seed . -1,1 



ofCatalpa. 464, Seed ofWillow. 466, Seed of Cotton. points, aS in the Ovules. 



589. The seed kernel mat consist op two parts, the embryo and 

 albumen, or of the embryo only. In the former case the seeds are 

 albuminous, in the latter, exalbuminous, a distinction of groat import- 

 ance in systematic botany. 



590. The albdmen is a starchy or farinaceous substance accom- 

 panying the embryo and serving as its first nourishment in germina- 

 tion. Its qualities are wholesome and nutritions, even in poisonous 

 plants. Its quantity when compared with the embryo varies in every 

 possible degree ; being excessive (Ranunculacese), or about equal (Vio- 

 laceae), or scanty (Convolvulaoese), 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 pawpaw, ivory-like in the 

 ivory-palm (Phytelephas), fibrous in cocoa-nut, where it is also hollow, 

 enclosing the milk. 



691. The bmbrto is an organized body, the rudiment of the future 

 plant, consisting of root {radicle), stem- bud {plumule), and leaves 

 (cotyledons). But these parts are sometimes quite undistinguisbable 

 until germination, as in the Orchis tribe. 



592. The radicle is the descending part of the embryo, almost al- 

 ways directed towards the micropyle, the true axis of the seed. 



593. The plumule is the rudimentary ascending axis, the terminal 

 bud, located at the base of, or between 



594. The cotyledons. These, the seed-lobes, are the bulky, fari- 

 naceous part of the embryo, destined to form the first or seminal leaves 



