176 THE STORY OF THE BIRDS. 
hand or tip joint of the wing) and the scaly condition 
of the shank and the number and arrangement of the 
song muscles. Higher birds have also fewer seconda- 
ries (quills growing out of the middle joint of the 
wing) than the lower birds, and many birds with 
sharp-pointed long wings, which feed on the ground 
much, have the feathers which grow out of the upper 
joint of the wing (tertiaries) next the body very long, 
as if they were in some way intended as an arrange- 
ment for rapid rising, which Nature was trying to put 
in without shortening, broadening or concaving the 
wing. 
One can look at a bird’s wing and know much of 
its way through the air, and draw some strong infer- 
ences about its story. 
