VI 



FORM AND FUNCTION 



165 



various intermediate stages before we arrive at separate- 

 toed feet. In the Dabchick and the other Grebes, the 

 toes are not connected, but there is on cither side of 

 each a broad expansion of skin. In the Kingfisher 

 the second, third, and fourth toes arc fastened together 



Fig. 43. 

 Foot of (i), Woodpecker ; (2), Grebe. 



for most of their extent. The Woodpeckers, Cuckoos, 

 and Toucans have a most curious form of foot called 

 zygodactyle or yoke-toed, the first and fourth toes 

 pointing backward, the other two forward — a foot 

 specially adapted for climbing. In the Swift all the 



