SPARROW'S BILL. 417 



They fly with their mouths open, and may often 

 be heard snapping at the insects on the way, and 

 making a noise somewhat like that produced by 

 shutting the case of a watch. 



Those birds, on the contrary, which catch their 

 prey by skimming the surface of the water, have 

 a long and peculiarly formed bill ; that of the bird 

 called the skimmer has the peculiarity of being 

 the shortest in the upper mandible, so that it 

 obtains its food, and can in no other way obtain it, 

 by pushing the small marine animals on which it 

 feeds before it on the surface of the water. The 

 common duck, as it pushes its long bill among the 

 weeds growing in the stagnant pool, must often 

 have been noticed to be in the habit of chattering 

 with its bill at the same time. In so doing, it 

 obtains the minute water creatures upon which it 

 feeds, rejecting those matters which are unsuited 

 to its purposes. 



We may select a yet more familiar bird, as an 

 illustration of the last variety in the form of the 

 bill, to which we can in this place direct attention. 

 The house-sparrow is possessed of a bill which is 

 a perfect model of strength and usefulness. This 

 little bill is thick and strong, sharp at the tip, and 



