OF HARTING. 355 



indicating the deposition of as many eggs in one 

 minute. 



The larva, like the perfect insect, is predacious, but, 

 unlike the latter, it is very sluggish and insidious in its 

 movements ; as a compensation, however, for this in- 

 active habit, it is provided with a prehensile apparatus 

 of a unique character. The under lip is unusually 

 developed, transversely hinged at its base, and again 

 about midway between that and its extremity, which 

 is armed with a pair of articulated toothed, or acutely 

 pointed forceps. This apparatus, when not in action, is 

 folded back, joint upon joint, so as completely to 

 conceal the mouth and part of the face ; but no sooner 

 has the truculent owner stealthily brought itself within 

 range of its intended and unsuspecting victim, than, 

 dropping the mask, literally as well as figuratively, it 

 suddenly dashes out the whole apparatus at the doomed 

 animal. This it seldom misses, and having seized it in 

 its labial forceps, it brings it to its mouth and there 

 retains it in a position to be conveniently operated 

 upon by the jaws, which make very short work of it. 

 The hinged lip is then refolded, and its various parts 

 are applied, as before, closely over the mouth and face 

 until another opportunity of making a similar capture 

 presents itself. 



Another peculiarity distinguishing the larva of the 

 dragon-fly is its mode of respiration, which is also 

 subservient to locomotion. At the extremity of the 

 abdomen is an orifice or spiracle, closed by a valve and 

 several plates ; when these are opened a quantity of 

 water is admitted into the body of the insect, and the 

 valve is closed. The water then undergoes a de- 

 oxygenising process, and, as soon as this is completed, 

 the valve is again opened and the effete water forcibly 

 expelled in a jet two inches or more" in length. The 

 immediate effect of this discharge is a sudden forward 

 propulsion of the animal itself. In its next stage of 

 development it exchanges this system of respiration 



z 2 



