INSECTS : STINGS AND OVIPOSITOES. 157 



coloured horn, appropriated to these instraments (wMch 

 is to them what steel is to us) ; and which we shall 

 presently discover to be composed of two blades exactly 

 alike, convex without and concave within, applied face 

 to face. One edge of this pair of implements is quite 

 smooth, but the other is cut into the most beautifully 

 regular and most minute teeth. 



This, however, is but the sheath. Within the two 

 spoon-shaped faces there lie two other lancets, blade to 

 blade, still finer and more delicate. Both edges of these 

 blades are of the most perfect keenness, without a flaw ; 

 but their sides appear roughened with rows of very 

 minute horny knobs, lie a rasp. 



I shall illustrate this demonstration by another ex- 

 tract from Keaumur, premising, however, that his ob- 

 servations refer to the large species of true Oicadce from 

 warmer latitudes, whose machinery seems to diifer 

 from that of our little friends in some particulars. 

 For example, the two inner lancets seem to be united 

 in one, in Reaumur's species, or else, which I think 

 more probable, he did not succeed in separating 

 them. 



He describes the two curved spoon-shaped pieces, 

 as finely indented on both sides with teeth ; which are 

 strong, nine in number, arranged with great symmetry, 

 increasing in fineness towards the point. This instru- 

 ment he describes as composed of three pieces, the two 

 exterior, which he calls the Jiles, and another pointed, 

 which he compares to a lancet, which is not toothed. 

 " The files are capable of being moved forward and 

 backward, while the centre one remains stationary ; 

 and as this motion is eifected by pressing a pin or the 

 blade of a knife over the muscles on either side at the 



