Yet it must be confessed that any attempt to explain, 
exactly how birds fly must fail. We can do no more than state 
the more obvious factors which are indispensable to flight, and 
the nature of its mechanism. The subtleties, and delicate 
adjustments of actual flight evade us. 
Our appreciation, however, of this supreme mode of 
locomotion will be materially quickened,if we make a point of 
studying the varied forms of flight as opportunities present 
themselves. 
To begin with, it is worth noting that the size of the wing 
decreases with the weight of the body to be lifted—up to a certain 
point, of course. This, perhaps, may seem strange a statement 
to make. But it can be readily verified. Compare, for 
example, the size of the body in relation to the wings, in the case 
of the butterfly and the dragon-fly, on the one hand, and the 
partridge and the crow, on the other. The two first named, 
by comparison, have enormous wings. 
Birds, it will be noticed, which haunt woods, or thickets, 
have short, rounded wings, like the wren, the pheasant, or 
the tawny owl. Such, on the other hand, as live in the open, 
like the gull, and the swallow, have long, pointed wings. The 
reason for this is fairly plain. Birds which must steer their 
course through the intricate mazes of a wood, or thicket, would 
find their flight seriously hampered by long wings. 
22 
