Ovipositors, with files, of the Grasshopper, magnified.
"But, Uncle Philip, what is the piece with the ridge for?"
"Ah, boys, that piece shows the wisdom and the goodness of God. 'His tender mercies are over all his works:' he has placed that piece there to keep the borers stiff, so that they cannot get out of joint, or be broken, when the little workman is boring."
"Well, this is very curious."
"Yes; but there are some of these insect workmen more curious still. Did you ever see a spy-glass? You know it is a round, hollow piece of wood, with brass tubes in it, which are made smaller and smaller, so as to slide into one another, when the glass is not used. Now there is a sort of gadfly (she is a little creature, too) which has exactly such a contrivance to keep her gimlet in. It is in four pieces, and the smallest piece ends in five sharp points, three of which are longer than the other two: she twists these five sharp points into one piece, and as some are longer and some shorter, when they are all put together, they make a sharp edge running all around, and are almost exactly like an auger or gimlet. When she wants to use it, she just shoots out the different tubes, so as to make a stem for the gimlet; and when she is done, she puts all back into its case again.
"Here is a drawing of it, and I think that by looking at it you will understand what I have been telling you: I do not know whether men learned from this part of the fly how to make the case of a spy-glass; but I know they might have learned.