The Root 



79 



root serves a tree is by anchoring it firmly to the ground 

 no simple task when you remember the masses of 

 leaves borne by some trees and the violent gales which, 

 in spite of these, they successfully resist. A tree which 

 like the birch or poplar has a flexible trunk easily swayed 

 by the wind does not need such 

 strong deep growing roots as the 

 oak which does not yield to any 

 gale until actually uprooted from 

 the ground. 



It has been suggested that 

 builders first took the idea of the 

 buttresses with which the walls 

 of churches and cathedrals are 

 strengthened from the way in 

 which a tree's roots grow out from 

 the trunk. Again, if you compare 

 these roots with the guide ropes of 

 a tent you will see how well they 

 are adapted to bracing up the tree. 

 If they grew out in one direction 

 only any strong wind could blow 

 the tree over sideways ; they 

 branch however on every side 

 equally. From these two instances 

 you will see that this second use 

 of the root is altogether mechan- 

 ical, that is to say it does not 

 depend on the root being alive, 

 but only on the way in which it 

 reaches down into the ground. 



Besides supporting and nourishing the tree itself, 

 the roots serve the additional purpose of binding the 



Fig. 40. Wheat seedling, 



with soil sticking to the 



root hairs. 

 N.B. The root hairs do 



not grow right to the 



ends of the roots. 



