30 NATURE TEACHING. 



also as the means whereby the water taken 

 up by the absorbing region is passed on to 

 the stem and leaves above ground. 



2. Roots frequently act as storehouses 

 of plant food, particularly in the case of bien- 

 nial plants. Biennials are plants which, in 

 temperate climates, require two years to com- 

 plete the cycle of their lives, producing during 

 the first year an abundance of leaves but no 

 flowers. These leaves manufacture plant food, 

 in the form of starch or sugar, in excess of the 

 plant's immediate needs and this surplus food 

 is stored away in the roots which usually 

 become very much enlarged. On the approach 

 of winter the leaves die down but the roots 

 remain in the ground in a dormant condition. 

 In the spring of the succeeding year the plants 

 put forth new leaves and finally flower and 

 produce seed, and, in carrying on these pro- 

 cesses, the store of food in the roots is drawn 

 upon so that by the time the seeds are ripe 

 the roots are practically exhausted. After the 

 seeds have been dispersed the plants die. This 

 condition of things may be well seen in such 

 plants as beet, carrot and turnip. 



3. The observations made on seedlings 

 have shown that the roots of a plant usually 

 arise from the radicle of the little plant in the 



