$o8 TREES, THE TITMOUSE AND THE WOODPECKER. 



from all danger in that quarter. The second process towards decay 

 is exceedingly curious, and cannot well be accounted for. If it 

 takes place to a serious extent, no art of man can possibly save the 

 tree ; and sooner or later, according to the magnitude of the disease 

 with which it has been tainted, it will fall before the force of the 

 raging winds. Should this disease be slight, the timely prevention 

 of rain from penetrating the injured part will secure the tree from 

 further mischief. 



I must here observe that, in animated nature, the vital functions 

 are internal ; so that, if the part within be mortally wounded, death 

 is the inevitable consequence. With most trees, and with all those 

 of Britain, it is otherwise. Their vitality is at the periphery, con- 

 nected with the bark, under which an annual increase of wood takes 

 place, so long as the tree is alive. Should, however, the bark be 

 cut away, the tree will die upwards from the place where all the 

 bark has been destroyed. Not so with its internal parts. You may 

 entirely excavate tire interior of a tree ; and provided you leave a 

 sufficient strength of wood, by way of wall, in order that it may be 

 able to resist the fury of the tempest without, taking care at the 

 same time to exclude the rain, your tree will remain in vigour from 

 generation to generation. The internal texture of a tree will perish 

 without any notice by which we may be forewarned of the coming 

 ruin. The disease which causes the destruction takes place in the 

 oak ; but more frequently in the sycamore ; and most commonly of 

 all in the ash. We will select this last tree by way of elucidation. 



Often, when arrayed in all the bloom of vegetable beauty, the ash 

 tree is seen to send forth from its bole, or from some principal 

 branch, a small fungus, which, during the summer, increases to a 

 considerable size. It ripens in the autumn, and falls to the ground 

 when winter's rain sets in. The bark through which this fungus 

 sprouted is now completely dead, though it still, retains its colour ; 

 and that part of the wood from which it proceeded is entirely 

 changed in its nature, the whole of its vitiated juices having been 

 expended in forming and nourishing the fungus. Nothing remains 

 of its once firm and vigorous texture. It is become what is 

 commonly called touchwood, as soft and frangible as a piece of cork, 

 which, when set on fire, will burn like tinder. In the meantime, the 



