46 SYLVICULTURE. 



exhausting winds, and against becoming overgrown with weeds 

 through too open a leaf - canopy overhead ; (3) that light- 

 demanding trees should be of quicker growth in height than 

 any shade - enduring kinds surrounding them, or should be 

 specially favoured during thinnings ; and (4) that during all 

 stages of growth each of the different trees intermixed should 

 have sufficient individual growing- space to provide for the 

 proper expansion of its crown of foliage and its root- system, and 

 more especially when the several trees are approaching their 

 maturity. The old British system of forming mixed woods 

 geometrically according to a stencil-like " planter's diagram," or 

 in alternate rows, &c., is not a sound system to go on, as it 

 gives no consideration to changes occurring in the soil and the 

 situation. These can only be properly taken into account when 

 variations in the composition, depth, moisture, and other 

 physical properties of the soil are noticed and provided for by 

 judicious admixture of the various kinds of trees individually, 

 or in small patches or groups of varying size, according to the 

 circumstances of each case and the local market for timber of 

 different kinds. A regular survey of the land to be planted 

 should be made three or four years before planting begins, so 

 as to estimate the number of plants of each kind wanted and 

 provide them from the nursery. Such groups may vary from 

 a small size up to many acres in extent. 



