CHAPTER XIV 



FEET AND LEGS 



ARRIED far and wide by the power of flight, 

 no two species of birds have exactly similar 

 environments. When the wings cease their la- 

 bour and are folded close to the sides, the bird must depend 

 upon its feet to carry it to its food and to keep it out of 

 danger, whether its footing be in a tree-top or on a cliff; 

 in shallow water or on the deep; in mud, sand, or snow. 

 Thus we realize the need for many varied adaptations 

 in the way of feet and legs. 



Although birds are descended from five-toed ancestors, 

 yet no living wild bird, and none of those which we know 

 only as fossils, has more than four toes on each foot. The 

 disposition of these toes four, three, or two, as the 

 case may be is always in accordance with the habits of 

 the bird. 



The most common type of avian foot is that in which 

 the arrangement is of three toes in front, with the fourth, 

 corresponding to our great toe, pointing backward. This 

 was the arrangement in our first bird, the Archceopteryx, 

 and for perching birds, as well as for many others with 

 very different habits, it has stood the test of six millions 



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