CHAPTER VIII. 
The Wings of Nestling Birds. 
‘““The blue eggs in the Robin’s nest 
Will soon have wings, and beak, and breast, 
And flutter and fly away.’’—Longfellow. 
The wing of the urhatched bird—Of the coots and water-hen—The Hoatzin’s 
wings—The wing of Archeopteryx—Moulting—The nestling game-birds and ducks 
—tTeaching the young to fly. 
T first sight it may seem a little strange to introduce 
A nestlings into a book devoted to birds in flight. But 
there are aspects of the wing of nestling birds which must, indeed, 
be borne in mind when considering the wing of the adult. 
It was pointed out, in Chapter I, that the wing of the adult 
had but three fingers and two wrist-bones. This condition 
represents the last stage in the evolution of the Avian wing. 
The wing of the nestling gives a clue to an earlier stage in its 
history. But we can get even further back than this. For if we 
examine the wing of an unhatched bird, we shall be able to get 
still nearer to the birth, and growth of the wing out of a reptilian 
fore-limb. Here as many as six wrist-bones may be found. 
And the “ palm-bones,” which in the adult are welded together, 
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