The Root 



77 



the shape of slugs, frosts and 

 irregularities in the soil and 

 so the root grows gnarled and 

 crooked. 



While the trunk of a tree 

 increases in size and in thick- 

 ness the root goes on growing 

 underground until it reaches 

 for yards and has formed quite 

 a network of smaller roots 

 reaching in all directions. The 

 principal root goes straight 

 down into the ground. The 

 roots next to it in size grow out 

 from it pointing slightly down- 

 wards, and they in turn give 

 out smaller branches, so that 

 among them they thoroughly 

 explore the whole of the ground 

 covered, and manage to extract 

 water from earth which, to look 

 at, anyone would say was ab- 

 solutely dry. Of course the 

 earth is often only sun-dried on 

 the top and the deeper roots 

 grow the more water they will 

 find. Thus the oak which needs 

 a good deal of water to grow 

 well makes sure of it by send- 

 ing roots right down into the 

 earth, while trees which, like 

 the firs do not want much, have Fig 38 

 roots which branch and spread 



Young Oak. Dicoty- 

 ledons have a principal tap 

 root from which the other 

 roots branch. 



