SEED. 



113 



(e. exalbuminosus) . The albumen may be very copious (Aconite, fig. 643), or extremely 

 thin and almost membranous ; in general it is largest when the embryo is smallest, 

 and vice versa. It is said to be farinaceous (a. farinaceum), when its cells are filled 

 with starch (Buckwheat, Barley, Oats, fig. 640; Rumex, fig. 644) ; fleshy (a. carnosum), 

 when its parenchyma, without being farinaceous, is thick and soft (Berberis, fig. 627 ; 

 Heartsease, fig. 645 ; Nightshade) ; mucilaginous (a. mucilaginosum) , when it is suc- 

 culent and almost liquid ; it is then rapidly absorbed, and may almost entirely dis- 



644. Rumex. 



Fruit 



cut vertically 

 (mag.). 



645., Heartsease. 



Seed 



cut vertically 

 (mag.). 



646. Poppy. 

 Seed cut 

 vertically 

 (mag.). 



647. Nympheea, 

 Seed (mag.). 



648. Rose Campion. 



Seed 



cut vertically 

 (mag.). 



649. Ivy. 



Seed cut 

 vertically 



(mag.). 



appear (Bindweed} ; oleaginous (a. oleaginosum) , when its parenchyma contains a fixed 

 oil (Poppy, fig. 646} ; horny (a. corneum), when its parenchyma thickens and hardens 

 (Galium, Coffee, Iris] ; like ivory (a. eburneum), when it has the consistency and 

 polish of ivory (Phytelephas). In Pepper and Nymphcea (fig. 647), &c., the seed 

 contains two sorts of albumen ; which will be 

 noticed when treating of the ovule. 



The embryo is axile, when its direction 

 corresponds with that of the axis of the seed 

 (Heartsease, fig. 645) ; it is peripheric (e. peri- 

 phericus], when it follows the circumference of 

 the seed, and surrounds the albumen (Rose 

 Campion, fig. 648) ; it is ruminate (a. rumina- 

 tum), when the testa or endopleura forms folds 

 which are projected in the interior of the seed, 

 and form incomplete septa in the thickness of 

 the albumen, like the folds found in the 

 double stomach of ruminating mammals (Ivy, 

 fig. 649), 



Germination. Germination is the action by which the embryo 

 grows and throws off its coats, finally supporting itself by draw- 

 ing its nourishment from without. 



The free end of the caulicle (fig. 650, T), terminated by the 

 radicle, usually enlarges the orifice of the micropyle, and 

 emerges ; soon the entire caulicle throws off its envelopes, with 65 nating ange c, 

 the cotyledons (c) and the plumule (G) ; the latter lengthens in 

 its turn, and its little leaves expand as it rises; at the same time the radicle 

 develops, and descends into the earth. If the caulicle, which is the first internode 



C50. Kidney-bean. 

 Seed germinating. 



gernn- 

 cotyledons 

 enclosed in the testa, T. 



