WOODS AND FORESTS. 305 



the tall or dominant trees. At the edges the trees 

 adapt themselves, as far as possible, to the conditions ; 

 but generally shrubs or small trees (often the same as 

 those found in the undergrowth) occupy vacant spaces 

 below the larger branches. This general foliage surface 

 shows very interesting variations, according to exposure 

 and other conditions. Thus, if a narrow and deep 



Fig. 38. —Diagram of a Section or Profile of a Wood. The fuliage 

 surface (F) is continuous but is not parallel to the contours of the ground. Near 

 the small stream in the valley, the trees and also the herbaceous plants on the 

 ground are much taller than at the summits of the hills. The wood-carpet (G) 

 is shown to be nearly continuous. Note also the convex curves of the foliage 

 surface at each end of the wood. 



ravine traverses the wood, the surface often runs across 

 it. The trees near the water are much taller than those 

 on the slopes. Then, again, if a river interrupts the 

 wood, there is a beautiful convex curve, which is 

 familiar to everyone, in the foliage surface. 



Any light, which passes through its leaves, is inter- 

 cepted either by the shrubby undergrowth, by bark 

 lichens and mosses, by Ferns, or by the mosses and 

 small flowering plants on the soil. The Undergrowth 

 in Britain is usually composed of Rosaceae (Raspberries, 

 Brambles, Hawthorns, Sloe, Rowan, or Roses). Honey- 

 suckle and Ivy are the only common creepers, and are 



(B7) u 



