GREAT WATER BEETLE. 241 



the whole of the body, and then, after having done its 

 work, is ejected in a series of tiny bubbles. So that 

 when these bubbles are seen, they will form an indi- 

 cation to the observer of the wealth of animal life that 

 exists below the surface. 



Owing to the great buoyancy of the Water Beetle, 

 it is obliged, if it wishes to remain below the surface, 

 either to continue the action of diving or to cling to 

 some object which will prevent it from being floated 

 upwards. The males are furnished with a remarkable 

 apparatus for this purpose. Three joints of the fore 

 legs are very much flattened and rounded, and are 

 covered on their under surface with a great number of 

 circular suckers, which act exactly like those of the 

 cuttle-fish. These suckers cling so firmly, that, as I 

 have seen myself, they retain their hold long after the 

 death of the owner, and may be seen sticking to the 

 stones of the pond after the beetle itself has putrefied 

 and floated off. 



When the Water Beetle is not alarmed or engaged 

 in the chase of prey, it is fond of floating at the 

 surface of the water with its head downwards, its 

 swimming legs stretched out at right angles to the 

 body, and the tips of its elytra just projecting in the 

 air. It is not easy to see the insect in this attitude, 

 because it is exceedingly wary, takes alarm at the least 

 movement, and dives below. On a fine summer's day, 

 it affords rather an amusing sight to steal up very 

 gently to a pond, and take up a place where the wate 

 can be observed closely. In doing this, the chief 

 precaution is to avoid throwing the shadow on the 

 water ; for so readily do these creatures take alarm 



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