270 FOOT OF THE WOODPECKER. 



differently, that when they are described as birds of 

 the same habit, a person who knew only one of them 

 would be apt to form a very inaccurate notion of the 

 other. The woodpecker cannot climb as the parrot 

 climbs, neither can the parrot climb as the woodpecker. 

 The woodpecker is a bark bird ; and though it can 

 adhere to the bark of a tree, so as to leave its bill, 

 neck, and head free for other action, it cannot adhere 

 in an inverted position ; and unless the crevices of the 

 bark are particularly favourable for its claws, it must 

 use the stiff feathers of the tail as a prop. Whether 

 it requires to do this or not, it must always bend the 

 joints of the leg so as to make the claws hold with the 

 requisite firmness. Its foot is in fact a sort of double 

 crab foot, the two parts of which hold on in opposite 

 directions. It is by the claws which are turned to the 

 front that the weight is suspended ; and those which 

 are turned to the rear, have their principal action in 

 tightening the hold of these. Then the line of the 

 body and tail acts in the same manner as a diagonal 

 strut under a beam ; and every one knox^s how small 

 a hold in the wall will support a beam if such a strut 

 is applied to it. The painter's scaffold, used in clean- 

 ing or repairing windows high above the ground, 

 which one sees every day in the streets, acts upon a 

 principle nearly similar to that of the woodpecker. 



Woodpecker. 



The above is the position of the foot when in the act 

 of holding: on. 



