PDF - Wallace Online

114 NATURAL SELECTION Varchitecture, however exquisitely beautiful, is false in principle,and is by no means a good example of the applicationof reason to the art of building. And what do most of usdo at the present day but imitate the buildings of those thathave gone before us ? We have not even been able to discoveror develop any definite style of building best suited forus. We have no characteristic national style of architecture,and to that extent are even below the birds, who have eachtheir characteristic form of nest, exactly adapted to theirwants and habits.Birds do Alter and Improve their Nests when altered Conditionsrequire itThe great uniformity in the architecture of each species ofbird which has been supposed to prove a nest-building instinct,may, therefore, fairly be imputed to the uniformity of theconditions under which each species lives. Their range isoften limited, and they very seldom permanently changetheir country, so as to be placed in new conditions. When,however, new conditions do occur, they take advantage ofthem just as freely and wisely as man could do. Thechimney and house - swallows are a standing proof of achange of habit since chimneys and houses were built, andin America this change has taken place within about threehundred years. Thread and worsted are now used in manynests instead of wool and horsehair, and the jackdaw showsan affection for the church steeple, which can hardly beexplained by instinct. In the more thickly populated partsof the United States the Baltimore Oriole uses all sorts ofpieces of string, skeins of silk, or the gardener's bass, to weaveinto its fine pensile nest, instead of the single hairs and vegetablefibres it has painfully to seek in wilder regions ; and,as already stated, Wilson, a most careful observer, believesthat it improves in neskbuilding by practice the older birdsmaking the best nests. More recently, Dr. Abbott, the wellknownAmerican naturalist, has studied the nests of theBaltimore Oriole. He found that, away from the habitationsof man, the orioles built concealing nests ;but in villagesand cities, on the other hand, where they were in no specialdanger from predatory hawks (or more probably from snakes)