lo Manifestation of Disease. 



Let us walk through a wood, and through 

 glades and avenues, and follow these manifes- 

 tations a little more fully before we take the 

 various diseases in detail. Premature defolia- 

 tion we shall find in crowded plantations, 

 owing to the absence of light and air, and if 

 this is excessive the functions of the organs 

 become affected and the flow of sap becomes 

 disorganised, when probably a hide-bound 

 condition will result. The fall of the green 

 leaf, too, accompanies sometimes various 

 insect attacks. 



The presence of lichen is not always serious, 

 even healthy trees we often find in our walk 

 more or less covered, and we pass it by as 

 unimportant ; but when the stem and branches 

 are covered we look upon it with suspicion, 

 especially in the case of larch. This may 

 arise from the presence of stagnant water, and 

 from overcrowding, and may be remedied by 

 drainage or judicious thinning if taken in time. 

 The effect upon the timber if in excess is to 

 render it dry and deficient in strength. 



This is almost invariably the result of 

 neglect or bad management. 



