TREES PLANTED FOR TIMBER 



149 



the flower. The nuts of the hazel are, to some extent, dispersed 

 by the nuthatch. This bird very cleverly wedges the nut in the 



FIG. 41. A, Prickly involucre, enclosing fruit of Sweet Chestnut ; B, leafy involucre, 

 with fruit of Hornbeam ; C, involucre and nut of Hazel. 



bark of some tree, then breaks open one end and picks out the 

 seed, often dropping it. The branches of the hazel form rods and 

 staves, which are used in making hoops for casks and as walking- 

 sticks. The hazel is often planted in hedges. 



TREES PLANTED FOR TIMBER 



Many of our woodlands, though by no means the majority, 

 are planted and maintained entirely for the sake of timber. When 

 this is the case many circumstances have to be considered. Some 

 trees naturally produce much more timber than others. From 

 this point of view that tree is best worth planting which will yield 

 the highest possible percentage of good timber and the least 

 possible percentage of firewood. When the branch of a tree is 

 cut across, the wood is seen to be of two different colours ; the 

 darker wood in the centre is the hard wood; the lighter, outer 

 wood, is the sap wood, which is useless for timber. Many different 

 kinds of woods may be seen at sawmills. The larch is naturally 

 a good timber-producing tree ; the oak, if left to itself, will be apt 

 to spread out horizontally, producing a short trunk and large 

 crown, and then the yield of timber is small. Some trees have soft 

 wood throughout ; the birch, for instance, has no hard wood. The 



