64 



gives exactly the l)readth of circle he chooses). But for 

 exhibition of the complete art of flight, a swallow on 

 rongh 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 witli its wings in 

 any ten seconds, and does consummately. The mystery 

 of its dart remains always inexplicable to me ; no eye 

 can trace the bending of bow that sends that living 

 arrow. 



But the main structure of the noble weapon w^e may 

 with little pains understand. 



72. In the sections a and h of Fig. 5, I have only repre- 

 sented 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, tj^pically representing the wing 

 of any bird, but actually founded chiefly on tlie seagull's. 



It is broadly composed of two fans, a and b. The 

 outmost fan, a, is carried by the bird's hand ; of which 

 I rudely sketch the contour of the bones at a. The inner- 

 most fan, B, is carried by the bird's fore-arm, from wrist 

 to elbow, 1). 



The strong humerus, c, corresponding to our arm from 

 shoulder to elbow, has command of the wdiole instrument. 

 Xo feathers are attached to this bone ; but covering and 

 protecting ones are set in the skin of it, completely filling, 



