COLEOPTEROUS INSECTS. 139 



Throughout the greater part of the year there is 

 scarcely a sheltered pool without a group of these 

 agile little creatures, pursuing their avocations with 

 the most sportive alacrity. Their chief occupation 

 is swimming rapidly along the surface in concentric 

 circles, or darting about in irregular gyrations, an 

 exercise which they keep up during the whole day, 

 without any apparent object but the love of motion. 

 Their bodies are so highly polished, that they shine 

 like a piece of burnished metal, and not a particle 

 of water can adhere to them. When approached 

 or otherwise interrupted, they speedily scatter or 

 dive under the water, but soon re-appear and resume 

 their sports. Their circular movements are no doubt 

 produced by the natatory legs on the one side being 

 more rapidly moved than on the other, as a boat is 

 turned when the rowers on one side cease to ply. 

 In collecting into parties, and leading up their mazy 

 dance together in the sunshine, we may suppose 

 these little creatures to be actuated by the same 

 social feeling which Mr Wordsworth has ascribed 

 to the gnat-like flies (TipulidcB\ which assemble in 

 choirs, and may be seen in sheltered situations 

 even in the middle of winter, alternately rising and 

 falling with a rapid undulatory motion. 



Nor wanting here to entertain the thought, 

 Creatures that in communities exist, 

 Less, as might seem, for general guardianship, 

 Or through dependence upon mutual aid, 

 Than by participation of delight, 



