34 THE TREE BOOK 



air. The maples, the horse chestnut, the ashes, 

 and many others follow what is called the op- 

 posite or fonr-ranked plan. It consists in hav- 

 ing each pair of leaves cover the space between 

 the pair below. Thus a pair of leaves starting 

 from opposite sides of the same joint and point- 

 ing north and south are set above a pair point- 

 ing east and west. The beech, sycamore, elm, 

 basswood, chestnut, linden, and many other 

 trees have the two-ranked plan. The leaves 

 are arranged in two flat rows, one on each side 

 of the twig. 



At first glance the top of a tree seems a mass 

 of disorder. But give it a moment's study and 

 you will note that it definitely follows the ar- 

 rangement of its leaf buds, although it is often 

 difficult to discover the law on the older parts 

 of the stem, as many branches have been de- 

 stroyed. This explains why, even from a dis- 

 tance, the experienced eye can distinguish the 

 kind of a tree by its form alone. Some trees 

 curve their branches either upward or down- 

 ward, like the lombardy poplar and the willow ; 

 others gBow them horizontally, like the apple 

 tree ; some prefer the holtow cup-fashion type ; 

 others build up in mushroom shape ; some fash- 

 ion themselves into pyramids tall and straight ; 

 and again others, like the birch, allow them- 



