Contents. 



Intruductory. — The Utility of Birds in Nature, 

 Chapter I. — The Value of Birds to Man, . 



Primitive Man's Relations to Nature, .... 



Chaiioed Relations iirodiiced by Agriculture, ... 



!Man at "War with Nature in the New World, . 



The Increase of Insect Pests, ...... 



The Number of Insects, ....... 



The Reproductive Cajjacity of Insects, .... 



The Voracity of Insects, ....... 



The Great Loss to American Agriculture by Insect Ravages, 

 Losses by Insect Ravages in Massachusetts, 

 The Capacity of Birds for destroying Pests, 



The Digestion of Birds 



The Growth of Young Birds, ..... 

 The Amount of Food required by Young Birds, 

 The Time required for Assimilation of Food, . 

 The Number of Insects eaten by Young Birds in the Nest, 

 The Amount of Food eaten by Adult Birds, 

 Birds save Trees and Crops from Destruction, 

 The Increase of Injurious Insects following the Destrvtction of 

 The Destruction of Injurious Mammals by Birds, . 

 The Value of Water-birds and Shore Birds, ... 

 The Commercial Value of Birds, ..... 

 The ^Ii^sthetic, Sentimental, and Educational Value of Birds, 

 Chapter II. — The Utility of Birds in Woodlands, . 

 The Relations of the Bird to the Tree, .... 



The Forest Planters, 



The Influence exerted by Birds and Squirrels on the Sue 



Forest Trees, 



The Tree Pruners, 



The Guardians of the Trees, ..... 

 Chapter III. — Birds as Destroyers of Hairy Caterfili 



Plant Lice, 



Chapter IV. — The Economic Service of Birds in the Orchard, 

 Chapter V. — Soncj Birds of Orchard and Woodland, 



Woodland Thrushes, 



Kinglets, .......... 



Nuthatches and Tits, ....... 



f Birds, 



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