i790 The Bird 
windpipe, and the effect is heightened by the rings which 
extend as far as the lungs, which are half-rings or semi- 
circles, the inner halves being replaced by membrane. 
This organ is peculiarly characteristic of birds, there 
being not a trace of it in any reptile. 
But though the syrinx alone is concerned in the pro- 
duction of sound, this may be modified, made resonant, 
or given a reverberating quality by a special structure 
or by windings of the trachea before it reaches the syrinx, 
and which are perfect analogies of human musical instru- 
ments. Many species of ducks have an enlarged box of 
bone, a kind of drum, on the lower portion of the trachea, 
sometimes of one shape, sometimes of another, serving, 
doubtless, to give power to the bird’s voice. Cranes and 
swans have veritable Trench horns in their breast-bones. 
The windpipe enters between the arms of the clavicles 
or wish-bone, and describes an $ or even a more intricate 
figure before passing out and dividing into the two bronchial 
tubes. When a Trumpeter Swan stretches out its neck 
and utters a musical clang, most maligned by comparing 
it to a whoop, we should remember the cause of its mellow- 
ness. In the majestic Whooping Crane of our Western 
States, which in a few years will have vanished from the 
earth, the windings of the trachea reach their maximum. 
The entire windpipe of this bird is four feet in length, and 
of this, one-half is coiled within the sternum, or breast- 
bone, giving remarkable volume and resonancy to the 
voice. 
