BRITISH FOREST TR1.I -.> 161 



less capable of being called forth into active life than on 

 the younger portions ol the tree with their thinner and 

 softer covering of bark, and a greater abundance of sap. 



Liability to Suffer from External Dangers. The dangers 

 to which the beech, in common with the other deciduous 

 broad-leaved trees, is exposed, are on the whole of far less 

 magnitude than those by which the conifers are threatened. 

 The beech-nuts are often eaten up by mice and voles. Late 

 frosts in spring, and the scorching midday sun in summer, 

 though both mitigated by shelter from the parent trees, 

 are injurious to the seedlings, which break into leaf just 

 when the greatest danger from frost may be apprehended. 

 Late frosts are less to be feared on the higher-lying tracts and 

 uplands, and on the cool northern and eastern exposures, 

 where seed is later in germinating, and saplings do not 

 break into foliage so early as on lower and warmer localities. 

 Old forests, too, are often affected in growth when late 

 frosts destroy their young and tender foliage in May. 



As the worst storms generally occur when the trees are 

 bare, the beech does not suffer greatly from the violence 

 of winds, and the same may also be said with regard to 

 accumulations of snow and ice on the branches. 



From the attacks of insect enemies it is comparatively 

 ree. Species of Melolontha in their grub state injure the 

 roots of seedlings, and larvae of Agrilus viridis, Scolytus 

 intricatus, and species of Dryocetes damage the cambium and 

 sap-wood of young growth, whilst the caterpillars of 

 Dasychira pudibunda and Liparis inonacha destroy the 

 foliage and buds in the older stages of growth, as also in 

 a less degree do beetles of the species Orchestes, Phyllobius, 

 and Rhynchites ; the timber is liable to be bored by the 

 larvae of Hyleccctus dermestoides and Ptilinus pectinicornis. 



A cankerous disease of the stem is caused either by 

 Nectria ditissima, or by the beech-aphis Chermes fagt\ or 



M 



