80 The Bird 
the body of the chicken, and is very different from our 
own breast-bone, which is long and narrow. ‘The pos- 
terior edge of the sternum is of many shapes, varying in 
birds of different species. Deep channels may extend 
into each side, leaving long slender splinters or spines 
Fic. 57.—Ribs and sternum of Flamingo; notice what a complex box of bone 
is formed by the vertebrx, scapula, ribs with their uncinate processes, and 
the sternum; notice large keel for the attachment of flight-muscles, 
of projecting bone, or this channel may be partly closed, 
forming a round hole quite through the bone. The 
sternum and its various processes are of considerable 
value in classification, the same configuration being found 
throughout allied groups, in consequence, doubtless, of 
the slight chance of modification resulting directly from 
any specialized habits in the life of the bird. The portion 
