LEAF EXPOSURE TO SUN AND AIR. 



97 



Figs. 81 and 82 show the remarkable difference in arrangement 

 in different branches of the Deutzia, and equally interesting 



\. 



f IG. 82. — Opposite Leaves of Deutzia, as arranged on a vertical branch. 



Fig. 83. — Leaf of Castor-Oil Plant, seen from above, showing exposure 

 to sunlight. (Much reduced.) 



modifications may be found in alternate-leaved trees, such as 

 the elm and the cherry. 



