COMPAEING BILLS. 



To walk through a museum, looking at the different kinds 

 of bills that the birds have, and wondering how they are used, 

 is almost as much fun as choosing the pretty things in a store 

 window. Until one tries it, it is hard to believe that there 

 can be so many shapes, — noses that tip up and tip down, 

 Roman-nosed and straight-nosed birds, and a hundred noses 

 that we have no name for. For bills are noses — and mouths 

 too. The bird's nostrils always open somewhere along the 

 upper portion of the bill, so that the whole upper mandible 

 forms an exaggerated nose. Indeed, one of our commonest 

 names for describing a certain kind of nose, the word aquilirie, 

 indicates the resemblance of a bold, humped nose to the 

 hooked beak of aquila, the eagle. 



Fig. 28. Head of Swift. 



Among our North American birds the smallest bills of all 

 are those of insect-hunters like the swifts, swallows, and 

 night-hawks, which have merely a tiny triangle of bill pierced 

 by the two nostrils. But what a mouth they have ! Open it 



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