364 THE WORLD OF ANIMAL LIFE 



every direction, and to keep a careful watch for both enemies and 

 victims. 



We must be careful in handling this curious beetle, for between 

 the hinder legs is a short, sharp spike. If it can, it will force 

 its body backwards between our fingers, and drive this spike into 

 our flesh. 



Now let us learn something about the life and habits of our 

 Great Water-Beetle. Being an insect, it of course begins life as 

 an egg. This soon hatches, and produces a little grub with a long, 

 slender body, a pair of big sickle-shaped jaws, and a curious tufted 

 appendage at the end of its tail. 



Almost as soon as this little grub makes its appearance in the 

 world it begins to eat; and in eating it spends almost the whole 

 of its life, until it is a grub no longer. It feeds upon living 

 victims, which it contrives to capture in almost incredible numbers. 

 Yet it cannot swim very fast. It has no paddles, like the perfect 

 insect, with which to row itself through the water; neither can it 

 drive its body along by forcibly ejecting a jet of water, like the 

 cuttle-fish, the piddock, and the grub of the dragon-fly. But it 

 secures its prey by cunning. 



It hides among rubbish, and patiently waits until a tadpole, 

 a grub, or other small creature comes within reach, when it seizes 

 it, and having reduced its victim to a mere shell, throws it away. 



The grub of the water-beetle has a curious, tufted appendage 

 at the end of its body. This is the breathing organ, and com- 

 municates with the air-tubes, which in this grub, just as in every 

 other insect, run throughout the whole of the body, even to 

 the tips of the "antennae", or horns, and the claws. In order to 

 breathe freely, the grub has only to keep the tip of this organ just 

 above the surface; and so it always lies in wait for its prey in 

 shallow water, where it can lie at the bottom, or in weeds and 

 leaves, and yet keep the end of its breathing organ protruding 

 from the water. 



When this larva is fully grown it leaves the water, burrows 

 into the muddy bank, and there makes an oval cocoon. In this 

 it changes to a chrysalis, or pupa, from which, in due course of 

 time, the perfect beetle emerges. 



