THE WOODPECKER'S TOOLS: HIS FOOT 79 



ward. But a sensible objection may be raised, 

 namely, that as there are two hind toes of un- 

 equal length, it is by no means certain which is 

 the more necessary. 



Scientists tell us that a woodpecker's foot, 

 though it looks so unlike a chicken's, is really 

 very much the same. When we ask how one 

 of the front toes disappeared and 

 how the extra hind toe came to be 

 where it is, they tell us that there 

 has been no addition and no loss, 

 but the extra hind toe is only a 

 front toe turned backward. They 

 call it a reversed fourth toe. A 

 bird's toes are numbered in order 

 starting with the hind toe and go- Diagram of 

 in^ around the inside of the foot right foot. 

 to the outer or fourth toe. The hind toe is the 

 thumb, and the others are numbered in the same 

 order as the fingers of our hands. So we see 

 that the woodpecker's real hind toe is rather 

 small, like that of most birds. It looks very 

 much as if it had been found too small and as if 

 another had turned back to help it do its work. 

 Do you say that a bird cannot turn his toes 

 about in this way? Most cannot, to be sure, 

 but all of the owls can do it. An owl will sit 

 either with two toes forward and two backward, 



