ROOTS 



47 



ing of food. The older and tougher parts of the roots 

 cannot do this work for the reason that, as they grew 

 older, their surface became changed 

 in such a way that it no longer 

 admits water. 



The amount of water which en- 

 ters the roots of a plant is surpris- 

 ing. On a warm dry day more 

 than a quart enters the roots of a 

 sunflower of medium size. Think, 

 then, of the thousands of gallons 

 which enter the roots of a forest. 

 All this water moves through the 

 roots to the upper parts of the 

 plant; the roots are the paths to 

 the stem. So, to anchor the plant, 

 to take in water, and to furnish the 

 path to the stem are three functions 

 of roots. 



Another comes to mind when we FIG. 3. A single root-hair of 

 think of all the edible roots which wheat, showing its dose con- 



tact with grains of sou. 



find their way to our table. Of 



what advantage is a fleshy root to a radish ? The advan- 

 tage to us is plain enough, but what is the advantage to 

 the radish? If left to itself the radish will use the food 

 stored in its fleshy root to erect a stalk which will bear 

 flowers and fruit. Similarly many other kinds of roots 

 are used for the storage of food for later use. Thus a 

 fourth function of roots is storage. 



The roots are of use to the plant in still other ways. 

 Like some other parts of the plant, they seem ready as 

 need arises to do other than their regular work. Roots 



