112 THE LIFE OF A BIRD. 



the nest, it is necessary to caution the reader 

 against the supposition that too much importance 

 is in every instance to be attached to these parti- 

 culars or to any one of them. While, for example, 

 it would be easy in many instances for the natu- 

 ralist to decide upon the class to which the bird 

 belonged, simply upon looking at its nest, yet, on 

 the other hand, he might fall into serious error if 

 he were to assign with confidence a nest of one 

 form or class of materials to one species, and 

 another slightly differing from it to another species. 

 The following remarks of Audubon appear appro- 

 priately to close this part of our Life of a Bird. 

 " From the above facts, and many equally curious 

 which I have mentioned, respecting the variations 

 exhibited by birds in the manner of forming their 

 nests, as well as in their size, materials, and situ- 

 ation, it will be seen that differences of this kind 

 are not of so much importance as has hitherto 

 been supposed in establishing distinctions between 

 species supposed by some to be different, and by 

 others identical. To give you some definite idea 

 of what I would here impress upon your mind, 

 I need only say that I have seen nests of the 

 barn or chimney-swallow placed within buildings, 



