RELATIONS OF TREES TO BIRDS AND INSECTS. 311 



a scanty subsistence. The forest border is their nursery 

 and their shelter, but their best feeding-places are the 

 cultivated grounds. There is not a single species whose 

 means of subsistence are not increased by the clearing of 

 the forest and the cultivation of the land ; but they re- 

 quire a certain proportion of wild wood for their habita- 

 tion. Very few species build their nests in the trees and 

 shrubbery of our gardens, unless they are near a wood. 

 In that case the catbird often nestles in the garden, 

 that during the rearing of its young if may be near 

 the grounds that produce larvae. Most of the wood- 

 peckers, the Sylvias, and the small thrushes, including 

 some of OUT most valuable birds, cannot rear their young 

 except in a wild wood. Yet aU these, solitary as they are 

 in their habits, increase under favorable circumstances 

 with the multiplication of insects consequent upon the 

 culture of the soil. It may be af&rmed as an indisputable 

 truth, that if their increase were not checked by the sport- 

 ing habits of men and boys, and the clearing and grub- 

 bing habits of " model farmers," birds of every .species 

 would increase in the same ratio with the multiplication 

 of their insect food, and proportionally diminish their 

 ravages. 



