THE cicada's last SONG 249 



blister upon its surface. Upon pressure from ei- 

 ther side this blister will be found to " snap," and 

 could we but repeat the operation with great ra- 

 pidity, a continuous sound would result. The toy 

 called the "telegraph ticker" is made on this prin- 

 ciple, the blister being made on a strip of steel, 

 and the click produced by pressure upon its top, 

 the elasticity of the metal bringing it back to its 

 original position of rest, and each motion accom- 

 panied by a snap as the blister changes sides. In- 

 deed, we need look no further than the bottom of 

 almost any well-ordered tin pan for a complete 

 illustration of this principle. So our cicada is a 

 drummer, and his favorite tune is a " roll-call," the 

 beats following each other with such rapidity as 

 to form a tone. All through the summer we 

 hear his strain. Even at this moment, as I write, 

 a very long-winded specimen is tuning up in the 

 tree just outside my studio window, and I am 

 almost moved to give him some good advice. 

 Have a care, my noisy minstrel. If it were I 

 alone who were within ear-shot of your noise all 

 might be well with you, but there are others near 

 by to whom your music hath charms. Have a 

 care! Only a moment ago I heard an ominous 

 hum on my piazza, and upon investigation discov- 

 ered a huge sand-hornet prying about the prem- 

 ises. He knows what he is looking for, and so 

 ought you, if your parents have done their duty 



