THE WOOD. 61 



the long arms extended. On the other hand, if 

 you go into a wood, the trees in which are planted 

 very close together, you will not find any with 

 horizontal branches. The trunks rise quite erect ; 

 probably they do not divide into branches till they 

 have reached a considerable height, or if they do, 

 the stems are nearly perpendicular. But examine 

 the trees on the skirt of the same wood; and 

 although they be of the same kind, and grow in 

 the same soil as those in the centre, they are 

 less lofty, but invariably spread towards the 

 open space. Here we see another wonderfully 

 wise provision of Nature. The tree which stands 

 in the middle of a field is exposed to the ac- 

 tion of the wind from which ever quarter it blows. 

 It does not therefore rise very high, or the wind 

 blowing against its leafy summit would exercise 

 on it a force similar to that of the human hand 

 acting on one end of a long lever (a crow-bar for 

 instance), and soon overthrow it. It is true, it 

 presents a very large surface to the action of the 

 wind, but the force exercised against it is coun- 

 terbalanced by the thickness of the stem (for un- 

 protected trees always have the stoutest trunks), 

 and by the very strong hold which its thick and 

 spreading roots have on the ground. Trees grow- 

 ing on the skirt of a wood have also low branches 

 and spreading roots on the exposed side, while the 

 inner branches are more lofty and approach nearer 

 to the perpendicular, their roots extending but to 

 a short distance when their support is little need- 

 ed. Those which grow in the central parts of a 

 wood, being protected by their neighbours from 

 the violence of storms, do not require spreading 

 roots to strengthen them, and therefore send their 



