i6 4 THE STRUCTURE AND LIFE OF BIRDS chap. 



to protect their legs from the formidable beaks among 

 which they had to run the gauntlet. The Woodpecker 

 pecks a hole in a tree in which to make his nest. His 

 beak is the hammer with which the Nuthatch, swing- 

 ing at the hips, cracks his nut. A Thrush may be 

 seen picking up a snail and dashing it on a stone to 

 break the shell. The beak is also used to preen the 

 feathers, even a short-necked bird being able to bring 

 it to bear on almost any part of his plumage. When 

 there is an oil-gland at the root of the tail, the bird with 

 his bill presses the oil from it and distributes it over 

 his feathers. The Tailor Bird uses it as a needle, and 

 partly to its skill are due the beautiful nests of many 

 of our small birds. 



The Foot. 



It will be enough to mention a few types to show 

 how the anatomy has adapted itself to different modes 

 of life. The normal number of toes is four, the fifth 

 or " little toe " having been lost. The first, as a rule, 

 points backward. The Emeu, the Rhea, and the 

 Cassowary have only three, having lost the first as well. 

 The Ostrich has only two, the third and fourth, and the 

 latter of these two is small and bears no nail. As in 

 the horse, it is the middle toe which carries all the 

 weight. Among English birds the most striking 

 difference is between the webbed feet of the swimmers 

 and the separate-toed feet of the perchers, climbers, 

 waders, and runners. The Gannet, the Cormorant, and 

 their allies have all four digits connected by the web ; 

 in most swimming birds the first is free. There are 



