THE WHIRLIGIG WATER-BEETLE 309 



These insects are not " bugs," as Thoreau inadver- 

 tently implies, but true beetles, and, moreover, beetles 

 endowed with resources far above the average of their 

 kind. Most beetles are content with existence in one 

 element, but the Gyrinus is equally at home in air or 

 water as the whim takes him. His hard polished back 

 conceals two gauzy wings which can be spread in a 

 twinkling, giving him all the agility of a fly upon the 

 wing, and which occasionally bring him in among the 

 buzzing throng around " our evening lamp," while his 

 peculiar equipment in the paddle-shaped feet of the 

 two nether pairs of legs gives him the lead in the race 

 among all the insect swimmers under the water. This 

 remarkable adaptability to a dual mode of existence 

 is further strikingly emphasized in the peculiar endow- 

 ment of vision. The whirligig-beetle has two distinct 

 sets of eyes; one large pair of goggles beneath its 

 head, with which it commands a continual view of its 

 lacustrine haunts while floating or circling on the sur- 

 face of the water ; and another pair on the lookout 

 above how keenly alert we all know, who have seen 

 the whirling swarm dive with their bubbles at our cau- 

 tious approach. 



Indeed, were I to search my insect cabinet for the 

 most appropriate emblem with which to close my pages, 

 I could scarce find a happier exponent of "Sharp Eyes" 

 all around the calendar than in our wide-awake, peren- 

 nial little Gyrinus. 



