98 ROOTS 



immerse it in the water for about an hour. Remove it and 

 note the change. 



Conclusion. How does this experiment show that the 

 skin absorbs water? 



Note. This exercise does not prove that all the absorbed water 

 comes in through the skin alone. There may be holes where root 

 branches were broken off through which the water may also enter 

 the root. 



Query. Why do roots wilt when removed from the 

 soil? How may they be revived? A grocer sometimes 

 puts vegetables which have been exposed to the sun and air 

 on his vegetable stand into a tub of fresh water. Why is 

 this done? 



To show that roots absorb water from the soil, fill two 

 flowerpots of equal size with equal weights of dry soil. Set 

 a plant in one. Water both flowerpots equally and set 

 them aside in a location favorable for growth. After three 

 or four days examine both flowerpots. Which contains 

 the drier soil ? What has become of the water ? How did 

 it escape from each? 



90. ROOTS 



Object. To discover the use of the skin of a root- 

 Apparatus. Two parsnips of nearly equal size and weight. 



Method. Carefully peel the skin from the larger pars- 

 nip until they are of the same weight. 



Put them in a dry place and weigh them from time to 

 time, or place them in opposite pans of a balance. 



What change takes place in the weight of these roots? 

 Which loses more rapidly? Why? 



Conclusion. What are two uses of a skin on a root ? 



