THE WHIKLW1G BEETLE. 253 



ingly short, wide, and flattened into a paddle-like 

 form, by means of which the insect can take those 

 short and quick strokes which propel it so swiftly over 

 the surface of the water, and enable it to turn with 

 such agility. When the insect is taken out of the 

 water, these paddle-legs are tucked under the body, 

 so that it only appears to have two legs i.e., the first 

 pair, which project in front of the head. 



It may be easily imagined that an insect whose 

 legs are thus modified does not make much progress 

 on land. Its attempts at walking are almost as awk- 

 ward as those of the sloth, for all the crawling that it 

 can do is managed by the two fore legs, the other two 

 pairs only moving the body by a series of jerky hitches. 



On the water, however, it skims over the surface 

 with consummate ease, forming graceful curves, like 

 those of a practised skater, and gliding about with an 

 equally apparent absence of effort. This perpetual 

 movement is necessary to enable the Whirlwig to take 

 its prey, which consists mostly of the tiny insects that 

 fall upon the water and cannot immediately free them- 

 selves. It is a very sociable insect, a solitary specimen 

 being rarely seen, and the Whirlwigs appear to take as 

 much pleasure in their sociable swim as do the gnats 

 in the perpetual rising and falling of their airy 

 dance. 



It has been said that in their gyrations they are so 

 active that they never strike against each other. This 

 is by no means the case. I have repeatedly seen 

 collisions take place, but without the least damage to 

 either party, the hard and polished armour of their 

 bodies effectually protecting them. 



