ROOTS AND THEIR FUNCTIONS 71 



CHAPTER VII 



ROOTS AND THEIR FUNCTIONS 



IN order to complete our story of the green 

 leaf and its duties to the plant, we must know 

 how the water is absorbed into the plant and 

 how it is transmitted to the leaves or other 

 organs where it is required. 



We might still keep the oak tree before us 

 as a concrete example in which to study these 

 things, and we should discover that it is only 

 by the roots that the tree obtains the water 

 it needs, and that these organs absorb it 

 directly from the soil in which the tree is 

 growing. 



If we attempted to pull the roots out of the 

 ground it would be found that, even in a 

 seedling tree, the task is not an easy one. 

 They penetrate the soil deeply, and ramify 

 widely through it. It is easier, therefore, and 

 for certain other reasons better, to study the 

 roots of a more easily accessible object say 

 a sunflower or any other herbaceous plant. 



On carefully digging out the roots of such 

 a plant, we should see that the tips are 

 smooth and conical, a shape well suited to bore 

 through the soil. At a short distance behind the 

 tip, the root is rather velvety or hairy, and it 



