THE WORK OF LEA VES 



219 



The ability to turn 

 toward the light must 

 be extremely useful. 

 Do all leaves have 

 this power? Experi- 

 ment with as many 

 plants as you can, 

 placing them before a 



window, or shading 126. Leaf mosaic of ivy Geranium. 



them on one side as they grow out-of-doors. Notice 

 any cases where the plants grow near walls or are for 

 any reason shaded on one side. Study especially climb- 

 ing vines, like the En- 

 glish Ivy, Boston Ivy, 

 etc. Do the leaves in 

 these plants seem to 

 avoid shading each 

 other? How do you 

 explain this? When 

 leaves cover over the 

 available space so as 

 to catch all of the 

 light without interfer- 

 ing with each other, 

 their appearance sug- 

 gests a mosaic (Figs. 

 126 and 127), and is 



127. Leaf-mosaic of Chestnut. Called a leai-mOSaiC. 



