INSECTS 1437 



edges, of which one remains keen and knife-like, 

 while the opposite edge is cut into several saw teeth 

 pointing backward. 



The lancets do not appear to be united with the 

 sheath in any part, but simply to lie in its groove; 

 their basal portions pass out into the body behind the 

 sheath, where you see a number of muscle-bands 

 crowded around them : these, acting in various di- 

 rections, and being inserted into the lancets at va- 

 rious points, exercise a complete control over their 

 movements, projecting or retracting them at their 

 will. But each lancet has a singular projection from 

 its back, which appears to act in some way as a guide 

 to its motion, probably preventing it from slipping 

 aside when darted forth, for the bulbous part of the 

 sheath, in which these projections work, seems 

 formed expressly to receive them. 



Thus we see an apparatus beautifully contrived to 

 enter the flesh of an enemy: the two spears finely 

 pointed, sharp-edged, and saw-toothed, adapted for 

 piercing, cutting, and tearing; the reversed direction 

 of the teeth gives the weapon a hold in the flesh, and 

 prevents it from being readily drawn out. Here is 

 an elaborate store of power for the jactation of the 

 javelins, in the numerous muscle-bands ; here is a 

 provision made for the precision of the impulse; and 

 finally, here is a polished sheath for the reception of 

 the weapons and their preservation when not in ac- 

 tual use. All this is perfect; but something still was 

 wanting to render the weapons effective, and that 

 something your experience has proved to be sup- 

 plied. 



