BIRDS 291 



in front and a long hind toe perfectly opposable to the middle 

 front one. This is the perching foot. Note the so-called 

 zygodactyl foot of the woodpecker, with two toes projecting 

 in front and partly yoked together, and two similarly yoked 

 projecting behind. Note the webbed swimming foot of the 

 aquatic birds; note the different degrees of webbing, from the 

 toti-palmate, where all four toes are completely webbed, pal- 

 mate, where the three front toes only are bound together but 

 the web runs out to the claws, to the semi-palmate, where the 

 web runs out only about halfway. Note the lobate foot of 

 the coots and phalaropes. Note the long slender, wading 

 legs of the sandpipers, snipe, and other shore-birds; the short, 

 heavy, strong leg of the divers; the small weak leg of the swifts 

 and humming-birds, almost always on the wing;' the stout, 

 heavily nailed foot of the scratchers, as the hens, grouse, and 

 turkeys; and the strong, grasping talons, with their sharp, long, 

 curving nails, of the hawks and owls, and other birds of prey. 

 In all these cases the fitness of the structure of the foot to the 

 special habits of the bird is apparent. 



Similarly the shape and structural character of the bill 

 should be noted, as related to its use, this being chiefly con- 

 cerned of course with the feeding habits. Note the strong, 

 hooked, and dentate bill of the birds of prey ; they tear their 

 prey. Note the long, slender, sensitive bill of the sandpipers; 

 they probe the wet sand for worms. Note the short, weak 

 bill and wide mouth of the night-hawk and whippoorwill, 

 and of the swifts and swallows; they catch insects in this wide 

 mouth while on the wing. Note the flat, lamellate bill of the 

 ducks; they scoop up mud and water and strain their food from 

 it. Note the firm, chisel-like bill of the woodpeckers; they 

 dig into hard wood for insects. Note the peculiarly crossed 

 mandibles of the cross-bills; they tear open pine cones for seeds. 

 Note the long, sharp, slender bill of the humming-birds; they 

 get nectar and insects from the bottom of flower-cups. Note 

 the bill and foot of any bird you examine, and see if you can 

 recognize their special adaptation to the habits of the bird. 



The most casual observation of birds reveals differences in 

 the flight of different kinds so characteristic and distinctive 



