ROOTS 93 



83. ROOTS 



Object. To determine just where growth in a root is 

 most rapid. 



Method. Arrange an apparatus as in Figure 33, suspending 

 the seedlings by means of thread and marking the young 

 roots with the marker shown in Figure 38. After a few 

 hours examine the roots and discover whether the lines are 

 equally distant as at the start. 



Where is the growth most rapid? 



84. ROOTS 



Object. To show that roots give off acid in growing. 

 Apparatus. As shown in Figure 34. 



Method. Fill the lower part of a funnel with gelatin 

 in which a little blue litmus solution has been dissolved. 

 When it has cooled enough to become firm below, insert 

 the root of a seedling. Cover the funnel with a glass plate 



and stand it in a rack or bottle. 



After a day or two note the change 

 in the color of the litmus. What 

 does this prove? 



Suggestion. Place young seed- 

 lings upon damp blue litmus paper. Ucelatin Litmus 

 Result? 



Suggestion. Place a slab of pol- FJQ 34 



ished marble in a flowerpot so that 



it is inclined towards the top. Lay a grain of germinated 

 corn or other seed near the top so that the roots when they 

 grow will lie upon the polished surface of the marble. 



Now fill the flowerpot with soil, and water it well. 



