26 BIKDS'-NESTING. 



with the scope of ideas and habits characteristic of 

 each species of bird. 



VARIABLE ARCHITECTURE. 



As an example of this discriminative phase of 

 bird-architecture, I may mention the remarkable his- 

 tory of Traill's flycatcher (Empidonax trailli) which, 

 in the typical form or as its " variety," ranges nearly 

 across the continent in the breeding season, through 

 the northern half of the United States and the con- 

 tiguous parts of Canada. 



The nest of this species is not to be looked for in 

 the high dry woods which its close cousin, E. acad- 

 icus, loves, but in low, wet and brushy places; it 

 makes its home in bushes rather than in trees. The 

 style of the nest, moreover, is totally unlike that of 

 the Acadian species, resembling more nearly the work 

 of the summer warbler (Dendrceca cestiva), but lack- 

 ing the compactness and neatness with which that 

 species weaves together the materials that make up 

 its home. Hempen fibres compose the exterior, or 

 body, of the nest, while internally it is lined in true 

 flycatcher style with fine grasses, and a slight admix- 

 ture of down from thistles ; the main point of all 

 characterizing it, however, is its position with regard 



