4 o 



THE BONES. 



bird is represented in its usual, and what may be called, 

 kneeling position ; the real knee, corresponding with B in fig. 

 2, of the leg being partly hid in the feathers, and the bend of 

 the leg beneath the tail corresponding with c, the remaining 

 part from that point to the claws answering to our foot and 

 toes. 



Stilted Plover. 



There are some other beautiful contrivances in the limbs of 

 birds, which deserve attention. Look at a bird fast asleep 

 with its head under its wing, resting usually on one leg, and 

 that again resting upon a perch not thicker than one's finger. 

 How apparently difficult and uneasy is such a position ! and 

 yet it is all made easy and safe to the bird by an admirable 

 piece of internal mechanism, which may be briefly thus 

 explained. Connected with the thigh-bone and leg, a set of 

 muscles run down to the very extremity of the toes, so con- 

 trived and placed, that when, by pressure downwards, the limb 

 bends, these fine muscles are pulled in, and therefore contract 

 the toes, thus making them grasp more firmly whatever the 

 bird is resting upon ; just as if a set of fine strings ran over 

 pulleys to certain hooks, and were acted upon at the other end 

 by a weight or pressure, and thereby made to draw in the 

 hooks. 



But there are some birds, and very large ones too, such as 



