ICHNEUMONS. 



57 



awl, but toothed like a saw, only the teeth, seven or 

 eight, are not oblique, but perpendicular, a structure 

 better fitted for acting upon clay, as the teeth will 

 not become so readily clogged, and the instrument 

 will be more easily retracted. The figures will make 

 this more perspicuous than the best description. 



, the Pimpla manifcstator ; 6, its ovipositor opened outwards ; 

 c c c e, magnified view of its ovipositor ; rf, the toothed point of the 

 borer. 



In order to study the economy of the mason wasps 

 (Odyneri) more effectually, Reaumur made an arti- 

 ficial vespiary of sand and mortar upon a wall, which 

 at the same time gave him an excellent opportunity 

 of observing the manoeuvres of the ichneumons. * I 

 perceived,' he tells us, 4 one of these ichneumons, 

 at the instant it alighted on the spot under which 

 so many of the little green caterpillars had been 

 stored up by the wasps. Its long tail, which it 

 carried horizontally, appeared to form but one bristle, 

 though it was really composed of three; and though 

 it carried it on a line with its body, it soon showed 

 me that it was capable both of raising and lowering 

 it, as well as of bending it in various directions, 

 and in different proportions to its length. It moved 

 its ovipositor so as to bring it into a bent position 

 under its body, protruding it even beyond its own 

 head; taking care to direct it into the barricadoed 



