VARIETIES OF WING AND OF FLIGHT 95 



they are things of wonderful beauty. We are 

 probably right in drawing from this flattening the 

 inference that the swifter movement of this part of 

 the wing makes a deep curve undesirable. The near 

 part moves more slowly and is more parachute-like 

 in character. The farther part, besides the momen- 

 tum of the bird as a whole, has the great rapidity 

 of stroke which sends it with a sudden dash both 

 forward and downward. We can hardly doubt that 

 the short, rounded wing is the primitive one. The 

 wing of Archseopteryx, most ancient of known 

 birds, did not taper to a point. And the clumsy 

 flyers — those with rounded wings have a compara- 

 tively feeble flight — must have preceded the skilled 

 flyers. The Hoatzin, with his very short, rounded 

 wing, cuts a very poor figure in the air. The Hoopoe 

 and the Jay are not strong flyers. It is not only 

 that their wings are short and very broad: there 

 are great interspaces, towards the hinder margin, 

 between the feathers. This, as I have shown above, 

 may aid automatically the maintenance of equili- 

 brium, but the gaps are wider and deeper than are 

 necessary for this purpose. In fact the Hoatzin's, 

 the Jay's and the Hoopoe's wings suggest the 

 work of a " 'prentice hand." 



The narrow wing is certainly not primitive. I 

 have shown above (see Chap, n) that most of the 

 work is done by the front part of the wings, and this 

 becomes increasingly true when the wing moves 

 very much forward, cutting the air at a small angle 

 with the horizon. This is the way in which the long 

 wings of the best flyers cut the air. And it is in 

 these best of flyers (I am not speaking of the Soarers) 



