238 



Descriptive Zoology. 



are two slender cartilaginous rods which pass backward 

 from the tongue under the angle of each jaw, up and for- 

 ward on top of the head, in some cases even nearly to the 

 tip of the bill. The cartilaginous rods furnish stiffness, so 

 that a muscular sheath can be effective. Woodpeckers do 

 good by destroying borers. Only one kind, the true sap 



sucker, or yellow-bellied wood- 

 pecker, uses the wood or sap, thus 

 being somewhat injurious. 



The Swifts and Humming 

 Birds. The birds of this order 

 have long, pointed wings, the 

 primaries being especially elon- 

 gated. The feet are small and 

 weak. The swifts are well known 

 to every one under the name 

 ''chimney swallows," but they 

 are not closely related to the true 

 swallows. The humming birds 

 are the smallest of birds and 

 among the most beautifully 

 colored. The tongue is long 

 and extensible, and is used in 

 securing insects from tubular flowers, over which they 

 are often seen hovering. 



The . nighthawk and whip-poor-will are in this order. 

 They are fitted for catching insects on the wing by the 

 very wide mouth, the gape extended far along each cheek, 

 while the bill itself is small and weak. These birds fly at 

 night or at dusk. When they light on a branch, they 

 always sit lengthwise, never crosswise, and, as they lie 

 quite flat and are of a grayish tint, they are very hard to 

 see. 



FIG. 143. NIGHTHAWK. 



From Packard's Zoology. 



