bands on the tree trunks. They spun down from the upper branches and fell 

 upon the unfortunate passers-by. They crawled through the grass in such num- 

 bers that it seemed to move in a mass as one looked down upon it. Under 

 these circumstances, birds might be expected to do strange things — and they 

 did. 



"The pair of Downy Woodpeckers which lived near us w-ere frequently 

 seen on the ground picking up the crawling tent-caterpillars. They seemed 

 to prefer taking them from the ground to taking them from the trees, though 

 there were more on the tree-trunks than on the ground even. And the Wood- 

 peckers seemed to have no difficulty in moving on the ground, though they 

 moved more slowly than when dodging around a tree. 



"Two mountain-ash trees on the place were infested by borers, though only 

 slightly and only near the ground, and at the foot of one of these trees the Downy 

 Woodpeckers made many a stand, while they probed the borer-holes with their 

 bills. 



"The Cuckoos came boldly into the village and fed and fed, flying about 

 quite openly. The Nuthatches flew to a band of caterpillars on a tree-trunk, and 

 were so busy and absorbed in devouring the crawlers that I could put my hand 

 on them before they started to fly, and then they merely flew to another tree 

 close by, and attacked another mass of caterpillars. 



"Blackbirds waddled over the grass by the sides of the streets picking up 

 the crawlers, and even a Woodcock spent several hours in the garden and on 

 the lawn, apparently feasting on tent-caterpillars, but I could not get near 

 enough to be sure. 



"The Vireos — White-eyed, Red-eyed and Warbling — the Cat-birds, Cedar- 

 birds, and Rose-breasted Grosbeaks did good service to the trees and human 

 beings, but the most evident destruction was done by the Chipping Sparrowfe 

 when the moths emerged late in the summer. The moths were very abundant 

 after four o'clock in the afternoon, flying about the trees to lay their eggs, and 

 then tlie Chippies became fly-catchers for the time, and flew straight, turned, 

 twisted, dodged, and tumbled 'head over heels and heels over head' in the air, 

 just as the course of the liunted moth made necessary. A quick snap of the 

 beak, and four brownish wings would float down like snowflakes, and their 

 numl^ers on the walks, roads and grass showed how many thousands of moths 

 were slain. In spite of the unwonted exercise the Chippies waxed fat. but not 

 as aldermanic as the Robins, which, earlier, gorged themselves on the cater- 

 pillars until, as one observer said, 'their little red fronts actually trailed on the 

 ground.' " 



The extent to which trees are subject to attack and their consequent need 

 of insect destroyers may he more dearly understood if we consider for a moment 

 the life of a tree in connection witii the insects that prey upon it. Let us take, 

 for example, the oaks of the genus Qucrcus. At the very l)eginning, before the 



