20 INTRODUCTION. 



countries the art has reached a higher development. 

 The purpose of the nest is merely to secure the safety 

 of the eggs and young, and it is not quite clear why 

 such very different methods should be pursued to 

 accomplish this rather simple matter. A strong cup- 

 shaped nest, inconspicuously placed, would seem to 

 be all that is necessary ; but instead of this, we have 

 long pendent nests on the terminal twigs of elm- 

 trees, and showy nests on slight shrubs, even some- 

 times decked out with bits of newspaper. There are 

 swallows that build clay houses on the outside of 

 bridges or barns where everybody can see them, in- 

 stead of placing them in the nooks and corners where 

 they would be concealed even from that arch-villain, 

 nobody's cat. Some birds will hollow out a deep 

 cavity in the sound wood of a healthy tree, when 

 next door there is a natural hollow in dead wood, 

 just as warm, as capacious, and as safely situated ; 

 and the great crested flycatcher advertises his home 

 by hanging a snake-skin where the door-knob ought 

 to be, if he had use for one. 



There have been many learned essays written about 

 birds' nests and a variety of conclusions reached, but 

 it is, after all, much a matter of theory. Had there 

 been good field ornithologists in the earliest days of 

 bird-life and the record of the race kept until the 

 dawn of history, a great deal would be intelligible 

 now that must forever remain a mystery. But there 

 is one important fact of which we must not lose sight : 

 the fashions are slowly changing. There is one bird 

 we call a " chimney-swallow," but these birds were 

 about before the first chimney was built, and so lived 



