28 BIRDS' NESTS 



we are perfectly justified in coming to the conclusion 

 that birds are in no way influenced by the appliances 

 they possess in building their nests. The whole 

 evidence is too contradictory to prevent us taking 

 any other view of the question. We have now seen 

 that birds are capable, quite irrespective of the form 

 of their bills and feet, of making elaborate nests of 

 matchless beauty, or poorly fabricated and very plain 

 in appearance respectively and according to circum- 

 stances; and I think, therefore, that we may safely 

 rest assured that the nest-building capabilities of birds 

 are not in any way subordinate to their natural ap- 

 pliances or tools for making their nests, but are 

 regulated by and subordinate to the various conditions 

 under which their young are produced, and especially 

 by the colour of the eggs.^ 



When we come to consider the question. Why so 

 many species of bird build a different kind or type of 

 nest (often great divergency is displayed by species 

 obviously very closely allied), we come to a matter 

 which is immeasurably more difficult of explanation. 

 We have not only to take into consideration the 

 general type of nest, but the infinite diversity of 

 materials. Dr Wallace seeks an explanation by 

 suggesting that birds select those materials which 

 are nearest to hand and easiest to obtain. But in 

 opposition to this we are confronted by the fact that 



1 For information bearing upon this portion of the subject the 

 reader may be referred to my Story of the Birds and other works. 



