CHAPTER X 
LEAF ARRANGEMENT FOR EXPOSURE TO SUN AND AIR; 
MOVEMENTS OF LEAVES AND SHOOTS 
- 149. Leaf Arrangement.!— As has been learned from 
the study of the leafy twigs examined, leaves are quite 
’ Fie. 105. — Leaf Arrangement 
of the Oak. 
around the stem. In horizon- 
generally arranged so as to 
secure the best possible ex- 
posure to the sun and air. 
This, in the vertical shoots 
of the elm, the oak (Fig. 105), 
the apple, beech, and other 
alternate-leaved trees, is not 
inconsistent with their spiral 
arrangement of the leaves 
tal twigs and branches of the 
elm, the beech (Fig. 196), 
the chestnut, the linden, and 
many other trees and shrubs, 
the desired effect is secured 
by the arrangement of all the 
. Fic. 106.— Leaf Arrangement of 
European Beech. 
leaves in two flat rows, one on each side of the twig. 
1 See Kerner and Oliver’s Natural History of Plants, V 
* 140 
ol. I, pp. 396-424. 
