The Framework of the Bird 85 
which would hardly afford strength for a single wing- 
flutter. Since mammals in their high evolution have 
found no use for this bone, it has become reduced to a 
small projection on the shoulder-blade. 
The clavicle we will recognize instantly, when we 
give it another name—the wish-bone or merry-thought. 
Fic. 60.—Pectoral girdle of bird (scapulas, coracoids, and clavicles); compared 
with the scapula and coracoid of a young Leopard, the latter bone in the 
Leopard being reduced to a tiny process. 
In birds the wish-bone is generally V-shaped, the two 
clavicles usually meeting and fusing at their tips. Through 
this V-shaped opening in the neck, the cesophagus and 
the windpipe pass from the throat into the body cavity. 
We too have wish-bones, although they are not placed 
exactly as are those of a chicken. We call them collar- 
bones, but by whatever name we know them they are 
of importance, both in ourselves and in birds, in serving 
to brace out the shoulders. In creatures which, unlike 
