564 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 2 8 



sound-rasps and scrapers have evolved, so that sound can somehow 

 function in their lives. In the ants, too, similar sound-making 

 proclivities have been shown in some instances. Although the ants 

 and the beetles, even to the larval stages that know none of the 

 moods of the sex impulse have become greatly concerned with sound 

 production, little is known of their notes. Their sounds never con- 

 stitute the poetry of earth so dear to the human mind. Moreover, 

 many of these sounds unquestionably are not even perceptible to 

 human ears, because they are beyond the range of audition. One 

 must think of sound at times in terms of Avave impulses, as one does 

 of light. The sound spectrum, so to speak, may at both ends extend 

 far beyond human auditory powers, the vibrations being too rapid 

 at the higher extreme and too slow at the lower extreme to affect the 

 auditory mechanism in terms of sound. 



INSECT MUSIC WHICH AVE ORDINARILY HEAR 



We are at present concerned with only those great groups of insects 

 which impress their sounds upon the daily consciousness of our lives. 

 These insects are so large and so persistent in their sound making 

 that they produce a greater volume of noise than that made by the 

 ants or beetles. There are only two families which may at times 

 fill our ears with sound ; the cicadas, or so-called harvest flies of the 

 order Hemi/ptera^ including the true bugs; and the grasshoppers, 

 crickets, and katj^dids of the order Orthoptera. 



HOW THESE INSECTS MAKE THEIR SOUNDS 



Birds are the great vocalists of the earth. With few exceptions 

 they sing by means of a very efficient larynx within their throats. 

 Some few, as, for instance, the nighthawk, produce noises in a unique 

 manner with their wings while falling like a stone through the air 

 from great heights. Others drum with their wings upon the air like 

 the ruffed grouse, or flirt out queer bleating sounds with their tails 

 while on the wing like the snipe. Such specialized modes put these 

 wing or tail singers in the class with the instrumentalists like the 

 insects. Strange it is that nature, in the case of these birds and 

 that of a Turkestan lizard, which chirps with its tail, has somehow 

 overlooked the throats and vocal cords, preferring for some myste- 

 rious reason to make these creatures the unique instrumentalists of 

 their class. 



Insects are never vocalists like the birds, but always instrumental- 

 ists. The cicadas or harvest flics, witli their loud zinging, represent 

 one great distinctive group of insect musicians, to which the so-called 

 17-year locusts belong. All members of this group make their music 

 within specialized body cavities by means of thin chitinous mem- 



