THE WATER BOATMAN. 391 



like an oar, or by having a dense fringe of hairs 

 upon them. The water-beetles, after rising to 

 the surface of the stream for a supply of fresh air, 

 dive down to their watery home again, taking a 

 clear silvery bubble along with them ; and, in this 

 action, they move with con- 

 siderable rapidity their swim- 

 ming legs, which are clothed 

 with hairs. The water boatman 

 swims upon his back by means 

 of his singularly formed legs. 

 The little whirl-gig, of which 

 we have before spoken, swims 

 by means of its legs, which are paddle-shaped. By 

 means, it may be, of some peculiar secretion, which 

 repels the water, some insects can actually walk 

 upon its surface, and that as readily or more so than 

 upon land. Those who know the pleasures of 

 shooting with polished skates over clear ice, when 

 it almost seems as if we were moving in the air, 

 and no more condemned to earth, can imagine 

 something of the delight these insects must expe- 

 rience, who can glide as swift as thought over the 

 glassy surface of the brook. Sometimes the shape 

 of the hind-legs is remarkably altered, and, per- 



