STEMS 



111 



is plenty of light. After the eyes have sprouted compare 

 it with another potato which has been sprouted in a dark 

 cellar. 



How do you account for the difference? 



105. STEMS 



Object. Same as in Experiment 104. 



Method. The growth of root and stem in obedience to 

 light and gravity may be shown by arranging an apparatus 

 like the one shown in Fig- 

 ure 40. First arrange a 

 seedling as in (a), having 

 the roots immersed in the 

 water of the test tube. 



Wax well about the 

 top to prevent the water 

 from coming out. 



Then invert the appa- 

 ratus and fasten it in a 

 clamp. 



Observe the directions 

 taken by root and stem 

 (6). If placed where the 

 light comes from only 

 one side, notice the di- 

 rections in which both 

 stem and root turn. 



Conclusion. What do FlG 40 b 



you infer from this as to 



the effect of light on direction of growing roots and growing 

 stems ? 



..Stem 



...Stopper 



Root 



.Water. 



Stopper. 



Stem 



