402 OPERATIVE TOOLS. 



The carpenter, or carpentress which owns it, is the female 

 Tree-hopper, or Cicada, who thus cuts the branches, while her 

 mate " bursts the very shrubs" by his shrilly music. 



Our next more simple instrument is an awl, or piercer, 

 which issues from a sheath, in form of a curved needle. It is 

 the piercing ovipositor of a Gall-fly, and, though a great deal 

 longer than the insect's body, is, by a mechanical contrivance, 

 nicely adapted to it. 



We have here another borer, or brad-awl, defended by a 

 sheath, which opens lengthwise, like a pair of compasses. The 

 awl itself is single, nearly three inches long, and terminates, 

 not in a simple, but a serrated point. This is the instrument 

 of that large common ichneumon, 1 which, for deposit of her 

 eggs, pierces through the clay defences of a " mason " wasp's 

 nest. 



Here, as seen in the microscope, is a small needle, a needle 

 of human manufacture. Its point appears " above a quarter of 

 an inch in breadth, not round nor flat, but irregular and un- 

 equal ; and the surface, so smooth and bright to the naked eye, 

 seems full of ruggedness, holes, and scratches, like that of a 

 rough iron bar." 2 



Beside this clumsy piece of workmanship is now introduced 

 another, by an infinitely more skilful hand, which exhibits " a 

 polish most amazingly beautiful, without the least flaw, blemish, 

 or inequality, and ending in a point too fine to be visible." 3 

 This we might suppose to be our insect weapon a natural as 

 contrasted with an artificial needle ; but no such thing ; it is 

 not the weapon, only the weapon's sheath. This opens longi- 

 tudinally ; and now we discover what it enclosed, viz. two 

 darts, distinctly separate even to the base. We can see further, 

 that these darts are each of them armed with ten saw-like teeth, 

 such as occasion the instrument, sheath and all, to remain fre- 

 quently within the substance wherein it may be plunged. In 

 truth, this is a formidable-looking tool of torment ; but poison 



1 Pimpla manifestator. * Hooke's " Micrographia." 3 Hooke. 



