92 



BIOLOGY FOR BEGINNERS 



all their stomates on the upper surface. In vertical leaves they 

 are evenly distributed. 



Chlorophyll. The green coloring matter of plants is the most 

 important part of the leaf. Practically the whole function of the 



CROSS 



FIG. 24. Leaf Structure. 



rest of the leaf is to expose the chlorophyll to light and provide 

 it with materials upon which to work. Chlorophyll is composed 

 of nearly all the elements we find in any plant tissue, but is espe- 

 cially rich in iron compounds which give it its green color. It is 



