THE WOODPECKER'S TOOLS : HIS TONGUE 103 



of the little bones just as the woven outside 

 covers an elastic cord. 



Not all woodpeckers have tongues precisely 

 like this. The sapsucker's is the shortest of any, 

 and reaches barely beyond the hinge of the 

 jaws. In the Lewis's woodpecker and others of 

 his genus the branches of the hyoid extend part- 

 way up the back of the skull ; but in the kinds 

 that live principally upon borers they are very 

 long and resemble the flicker's in arrangement. 

 The only other North American birds that have 

 a tongue built upon this plan are the humming- 

 birds, in which also it is extensile. The flicker, 

 in proportion to his size, has the longest tongue 

 of any bird known. 



