OPERATIVE TOOLS. 401 



as well as a cutting chisel. This, the compound tool, only 

 slightly varied with different possessors, is the only tool of the 

 "wasp mason, carpenter, and paper-maker." A pair of wasp 

 mandibles or jaws constitutes the instrument now before us. 1 

 A hard bony substance is the material of which this and nearly 

 all insect tools are constructed. 



A saw is the implement which next presents itself, a tool 

 much resembling, only more complicated than that of our own 

 carpenters : we may call it rather a pair of saws, or a compound 

 saw, when in use working simultaneously at one cut. The in- 

 struments are so exceeding fine and delicate as to need sup- 

 port, and we see accordingly, that their backs are set within a 

 groove. The teeth, instead of being simple, are denticulated 

 with others cut more finely, which confers on this tool the ad- 

 ditional properties of a rasp or file. 1 



What are its uses and by whom employed? Its purpose is 

 to cut grooves in the branches of trees and shrubs for reception 

 and protection of insect eggs; and the insect by whom the 

 grooves are cut is a maternal saw-fly. 



Here is another tool of surpassing nicety, lodged in a closely- 

 fitting sheath, from which, on slight pressure, it is seen pro- 

 truding. It is large enough for partial examination even by 

 the naked eye, and, when thus viewed, appears a spike of equal 

 thickness, except at the point, where it is broader and angular, 

 and on both sides indented with teeth. Now let us behold it 

 in the microscope. The teeth, strong and sharp, are, we can 

 see now, about twelve in number on either side, and diminish 

 in size as they approach the point. But what else reveals our 

 magnifier ? Why, it shows that the instrument which appeared 

 simple to our naked sight is made up in reality of three distinct 

 pieces, the two outer ones armed with teeth, and called 2 " files," 

 the central one pointed like a lancet, and not denticulate. 

 The side pieces can be moved backwards and forwards, while 

 the middle one remains stationary. 1 



1 See Vignette. 2 By Reaumur. 



