CHAP. I.] DIGGING. • 5 



thing has been provided for. It has been 

 already observed, that the two principal uses of 

 the root are, to give the plant a firm hold of the 

 ground, and to supply it with food. For the 

 first purpose, the root either spreads so widely- 

 through the surface soil as to form a sufficient 

 base for the height of the plant, or it descends a 

 sufficient depth into the earth to steady the part 

 above ground ; and in either case the growth of 

 the plant is wisely and wonderfully proportioned 

 to the strength of the support which the root 

 affords it. For the second purpose, that of sup- 

 plying the plant with nourishment, the root 

 divides at the extremity of each shoot into 

 numerous fibres or fibrils, each furnished at its 

 point with a sponsiole or spongy substance, 

 which affords the plant the means of absorbing 

 the moisture necessary for its support. It is 

 thus quite clear, that everything that tends to 

 nourish and increase the growth of the root 

 must contribute to the health and vigour of the 

 rest of the plant ; and that no plant can thrive, 

 the root of which is cramped in its growth, or 

 weakened for want of nourishment. This being 

 conceded, it is evident that the first step towards 

 promoting the growth of any plat t is, to pro- 

 vide a fitting receptacle for the roo*" ; and this 

 is done by pulverising the ground in which the 

 seed is to be sown, so as to render it in a fit 

 state for the roots to penetrate it easily. Thus 

 they will neither be checked in their growth for 

 want of room, nor be obliged to waste their 

 strength in overcoming unnecessary obstacles; 

 such as twining themselves round a stone, or 

 trying to force their way through a hard clod of 



