the ancestors of the pheasant were arboreal, and hatched their 

 young in trees. Otherwise all the wing-quills should develop 

 at the same time, and at the same rate. Here, then, is 

 another instance of what can be learned of the past history 

 of a bird by a careful scrutiny of the nestling. Sometimes 

 we shall find our evidence in the wing, sometimes in some 

 other organ. The sequence of plumage affords abundant 

 evidence of this. But that is another story. 



So much for the " intensive " study of the wing. A brief 

 reference must now be made to the constantly repeated 

 statement that nestling birds are " taught " to fly by their 

 parents. There is no evidence whatever to support this 

 belief : and much that goes to show its improbability. 



Failing more suitable sites, sand-martins will often elect 

 to build their nests in the crevices of the masonry of bridges. 



From the mouth of this substitute for a burrow is often a 

 sheer drop of many feet to the stream below. When the 

 nestlings, fuUy fledged, leave their nursery for the first time 

 they must either " fly " from the moment they take the first 

 plunge from the masonry, or die. Failing to make the appro- 

 priate movements of the wings nothing can save them from 

 a watery grave. There can be no " teaching " to fly. 

 Indeed, death no less certainly awaits every house-martin 

 when it plunges into space from the edge of the nest. The 

 appropriate wing-movements, necessary to produce flight, in 



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