82 ON VEGETABLE PHYSIOLOGY- 



embracing the germination of the seed, and the 

 formation and completion of a new plant. But 

 previously, it will be proper to inform you, that 

 the seed in its ordinary state, (of which the bul- 

 bous root is only a variety,) possesses two distinct 

 properties namely, the principles of early nutri- 

 ment, composed of a solid mass, in which starch, 

 mucilage, and oil are chemically combined ; 

 and the rudiments of a future plant consisting 

 of the radicle or embryon root in union with 

 the plumula or primary stem. Both are secured 

 in a strong capsule or shell, forming one or more 

 lobes or cotyledons ; some seed having only one 

 lobe, as wheat, oats, barley, the grasses, and the 

 like ; and others, (which more frequently is the 

 case,) two lobes. Of the latter, the kidney bean, 

 the germination of which we shall presently ex- 

 plain, is an example. It is also of importance 

 you should know, that seeds will not germinate, 

 unless moisture has free access to them; and hence 

 the use of watering or of rain after sowing and 

 planting. That though a due proportion of water 

 be applied, vegetation will not commence at a tem- 

 perature below forty degrees, from which warmth 

 is equally requisite with moisture to produce 

 germination. That under the combined advan- 

 tages of moisture and heat, the object cannot be 

 obtained until air be admitted to the seed ; hence 

 the use of turning up the ground by frequent 

 ploughing, digging, and raking 5 and that the 



