THE PHILOSOPHY OF J3IBDS' NESTS. 217 



beautiful in proportion than that of the blackbird, the 

 magpie, or the crow. The wren, having a slender beak, 

 long legs, and great activity, is able with great ease to 

 form a well-woven nest of the finest materials, and 

 places it in thickets and hedgerows which it frequents 

 in its search for food. The titmouse, haunting fruit- 

 trees and walls, and searching in cracks and crannies for 

 insects, is naturally led to build in holes where it has 

 shelter and security ; while its great activity, and the 

 perfection of its tools (bill and feet), enable it readily 

 to form a beautiful receptable for its eggs and young. 

 Pigeons having heavy bodies and weak feet and bills (im- 

 perfect tools for forming a delicate structure) build rude, 

 flat nests of sticks, laid across strong branches which 

 will bear their weight and that of their bulky young. 

 They can do no better. The Caprimulgidae have the 

 most imperfect tools of all, feet that will not support 

 them except on a flat surface (for they cannot truly 

 perch) and a bill excessively broad, short, and weak, and 

 almost hidden by feathers and bristles. They cannot 

 build a nest of twigs or fibres, hair or moss, like other 

 birds, and they therefore generally dispense with one 

 altogether, laying their eggs on the bare ground, or 

 on the stump or flat limb of a tree. The clumsy hooked 

 bills, short necks and feet, and heavy bodies of Parrots, 

 render them quite incapable of building a nest like 

 most other birds. They cannot climb up a branch 

 without using both bill and feet ; they cannot even 

 turn round on a perch without holding on with their 

 bill. How, then, could they inlay, or weave, or twist 



