II. THE SWALLOW. 79 



circling eagle floats an inconceivable time 

 without visible stroke : (fancy the pretty action 

 of the nwier wing, backing air instead of water, 

 which gives exactly the breadth of circle he 

 clioose*).- But for exhibition of the complete 

 art of flight, a swallow on rough water is the 

 master of masters. A seagull, with all its 

 splendid power, generally has its work cut 

 out for it, and is visibly fighting ; but the 

 swallow plays with wind and wave as a girl 

 plays with her fan, and there are no words 

 to say how many things it does with its wings 

 in any ten seconds, and does consummately. 

 The mystery of its dart remains always in- 

 explicable to me ; no eye can trace the bend- 

 ing of bow that sends that living arrow. 



But the main structure of the noble weapon 

 we may with little pains understand. 



72. In the sections a and b of Fig. 5, I have 

 only represented the quills of the outer part 

 of the wing. The relation of these, and of 

 the inner quills, to the bird's body may be 

 very simply shown. 



Fig. 6 is a rude sketch, typically representing 

 the wing of any bird, but actually founded 

 chiefly on the seagull's. 



