4 
STIRRING THE SOIL. [chap. i. 
fluous, and yet everything 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 propor¬ 
tioned to the strength of the support which 
the root affords it. For the second pur¬ 
pose, that of supplying the plant with nou¬ 
rishment, the root divides at the extremity 
of each shoot into numerous fibres or fibrils, 
each furnished at its extremity with a spon- 
giole or spongy substance, which affords the 
only means the plant possesses of absorbing 
the moisture necessary for its support. It is 
thus quite clear, that every thing 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 nourish- 
