356 The Bird 
specialized type of foot which is adapted to climbing or 
to swimming, so that any classification based on such 
similarity of locomotion is obviously false. 
From the tiny limbs of a hummingbird to the gigantic 
shanks of an ostrich, the legs of birds, with a very few 
exceptions, are covered with scales, most emphatic re- 
minders of the reptilian ancestry of both these extreme 
forms of feathered life. The real foot of a bird, as the 
term is used in speaking of other animals, extends to the 
backward-bending joint, or heel. Part of the lower leg 
Fig. 285.—Foot of Raven. 
is thus concealed by the feathers and skin, while the upper 
leg, or thigh, is generally wholly within the body, as we 
saw in the chapter treating of the framework. 
As before, we must call on the crow, in many respects 
standing very near the top of the scale of bird life, yet 
which has found it good to hold to the typical bird’s foot. 
And indeed it serves him well, for with it he can walk on 
snow or ice; wade in shallow water; perch in trees; scratch 
or claw the ground and hold down a crab’s carapace, 
while he extracts the edible portion. Not only this, but 
he can hop like a sparrow or walk like a lark at will. 
