114 NATURAL SELECTION V 



architecture, however exquisitely beautiful, is false in prin- 

 ciple, and is by no means a good example of the application 

 of reason to the art of building. And what do most of us 

 do at the present day but imitate the buildings of those that 

 have gone before us ? We have not even been able to dis- 

 cover or develop any definite style of building best suited for 

 us. We have no characteristic national style of architecture, 

 and to that extent are even below the birds, who have each 

 their characteristic form of nest, exactly adapted to their 

 wants and habits. 



Birds do Alter and Improve their Nests when altered Con- 

 ditions require it 



The great uniformity in the architecture of each species of 

 bird which has been supposed to prove a nest-building instinct, 

 may, therefore, fairly be imputed to the uniformity of the 

 conditions under which each species lives. Their range is 

 often limited, and they very seldom permanently change 

 their country, so as to be placed in new conditions. When, 

 however, new conditions do occur, they take advantage of 

 them just as freely and wisely as man could do. The 

 chimney and house - swallows are a standing proof of a 

 change of habit since chimneys and houses were built, and 

 in America this change has taken place within about three 

 hundred years. Thread and worsted are now used in many 

 nests instead of wool and horsehair, and the jackdaw shows 

 an affection for the church steeple, which can hardly be 

 explained by instinct. In the more thickly populated parts 

 of the United States the Baltimore Oriole uses all sorts of 

 pieces of string, skeins of silk, or the gardener's bass, to weave 

 into its fine pensile nest, instead of the single hairs and vege- 

 table fibres it has painfully to seek in wilder regions ; and, 

 as already stated, Wilson, a most careful observer, believes 

 that it improves in neskbuilding by practice the older birds 

 making the best nests. More recently, Dr. Abbott, the well- 

 known American naturalist, has studied the nests of the 

 Baltimore Oriole. He found that, away from the habitations 

 of man, the orioles built concealing nests ; but in villages 

 and cities, on the other hand, where they were in no special 

 danger from predatory hawks (or more probably from snakes) 



