WOOD NOTES WILD. 67 



It is generally believed that the booming is made with 

 the mouth, but careful investigation has convinced me 

 that the mouth has nothing to do with it. This peculiar 

 sound is produced by the pointed wings, stretched down 

 and firmly set, cutting the air. Perhaps it is true that 

 only the males indulge in this singular exercise. 



Though the night-hawk and the whippoorwill are often 

 taken for one and the same bird, the night-hawk never 

 sings "whippoorwill," nor does the whippoorwill ever 

 "boom." The whippoorwill has bristles on each side of 

 the mouth, and a rounded tail, while the night-hawk has 

 a forked tail and no bristles, and the plumage is dif- 

 ferently marked. Both have the singular habit of sitting 

 lengthwise of a limb. 



