LEAF EXPOSURE TO SUN AND AIR 149 | 
revolving table before a window and slowly turned during 
the hours of daylight? 
158. Review Summary of Chapter X. 
( For vertical twigs 
Leaf t 
eal arrangemen For horizontal twigs 
Apparatus for 
Movements of leaves . . Causes of 
‘ Uses of . 
Compass-plants 
: ( Positive . 
Heliotropic bending of stems 1 Negative 
NEG jf 
