LARVA OF THE WATER BEETLE. 53 



When full-grown, this larva is two inches in 

 length. Its colour is yellowish-brown, sometimes 

 one tint predominating, and sometimes the other. 

 The reader will see how this sombreness of hue 

 enables it to lie concealed upon the mud as it waits 

 for prey. At the end of its body are two slender 

 appendages fringed with hairs. These appendages 

 communicate with the breathing tubes which pervade 

 the body, and the larva may be observed in a position 

 resembling that which is assumed by the perfect 

 insect, the head downwards, and the extremity of the 

 tail just above the surface of the water, suspended 

 and balanced by the appendages. 



The mode in which this formidable creature 

 obtains its nourishment is very remarkable. The 

 mandibles are large, sharp, and curved. When 

 submitted to a good magnifier, they are seen to be 

 constructed on the same principle as the fangs of a 

 poisonous serpent, a hollow groove running throughout 

 their length. This groove is not left open, but is 

 closed for the greater part of its length by a 

 membrane, an aperture being left at the base. This 

 singular structure enables the larva first to plunge its 

 mandibles deeply into the body of its prey, and then 

 to suck out its juices through the hollow jaws. 



As is the case with the carnivorous Beetles 

 generally, the larva soon attains its full growth, and, 

 when the time is at hand for its change into the 

 helpless pupal condition, it takes itself to the bank, 

 up which it climbs, and, burrowing into the damp 

 earth, forms for itself a sort of round cell or cocoon, within 

 which it assumes the pupal form. Should the change 



