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 Archeopteryx, 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. 11) 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 (1 am not speaking of the Soarers) 
