The method by which the sound is produced may be illustrated by a simple experiment. Take a small piece of stiff, sized writing-paper or smooth Manilla paper, and by pressure with some rounded blunt instrument produce a slight hollow or blister upon its surface. Upon pressure from either side this blister will be found to "snap," and could we but repeat the operation with great rapidity, a continuous sound would result. The toy called the "telegraph ticker" is made on this principle, 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 accompanied by a snap as the blister changes sides. Indeed, 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 discovered a huge sand-hornet prying about the premises. He knows what he is looking for, and so ought you, if your parents have done their duty by you. Hereditary instinct at least ought to teach you that your drum should play second fiddle to that hornet's humming music. I remember once being the witness of the sad fate of an ancestor of yours who drummed not wisely but too well. He was monopolizing the neighborhood, just as you are doing now, when I noticed his principal effort was suddenly cut short in the middle in a most unusual manner. If he had been a singer I would have supposed some rival had clapped a hand over his mouth, so suddenly was the song abbreviated. In another moment there was a rustling among the leaves, as something fell from the tree in his immediate neighborhood. Down, down it dropped, its passage to the ground accompanied by one or two short, sharp, spasmodic tattoos on that same noisy drum. The object fell among some rocks, but before I could reach the spot the humming sound of a sand-hornet greeted my ears, and in a moment more the insect took flight directly across my path, and, what was more, he was not alone. Would you know who accompanied him? Look then on the picture on page 252, and have a care, my noisy friend, for the lineal descendant of that sand-hornet now hovers outside my doorway. He has a grudge against your tribe, and he is even now on your scent. Perhaps you may be interested to know what the hornet did with that rash ancestor of yours. Well, I will