102 Mr. J. Bucklaud o/i 



mighty school to learn her secrets I was lastingly impressed 

 by the way in which the care of the tree is kept up 

 throughout the changing seasons by bird life, each species 

 exerting its peculiar repressive influence upon the increase 

 of this or that one of the various forms which insects 

 assume. 



How dependent trees are on birds for their existence may 

 be gathered from the following illustration, instances of 

 which 1 have often seen when the services of one or more of 

 their natural protectors have been withdrawn. As many of 

 you probably know, trees breathe through their leaves. 

 Consequently, if the buds of the leaves are prevented from 

 developing, or are eaten, when developed, by caterpillars, 

 the tree is weakened. Many coniferous trees will die if 

 stripped of their foliage for one year. Deciduous trees, if 

 deprived of their respiratory organs for several years in 

 succession will also perish, though these trees linger as a 

 rule for two, or even three, years before finally succumbing. 



Nor is injury to its breathing-organs the only danger to 

 which a tree afflicted in this way is subjected. The tree, being 

 in a weakened condition, is at once beset by beetles and other 

 borers, who, multiplying rapidly under such favourable 

 conditions, tunnel under the bark until all the vital tissues 

 of the poor tree are wasted. Thus a tree, which might have 

 recovered from the injurj' to its lungs, falls a victim to the 

 attacks of an insidious enemy which took advantage of its 

 feeble state. 



Woodpeckers, or other birds of similar feeding-habits, 

 would have flown to the rescue of the tree and possibly 

 saved its life ; but when that corrective influence is missing 

 the tree must die. 



This illustration of the dependence of the tree on the bird, 

 and of the bird on the tree, is, of course, but one of a long 

 series that could be cited, and it is because of this most 

 delicate adjustment between the tree, the insect, and the 

 bird that I regard as })rofoundly true Frank M. Chapman's 

 statement " that it can be clearly demonstrated that if we 

 should lose our birds wo should also lose our forests.'' 



