FOOT OF WATER-LEETLE. 



025 



description comes very near to that of the hair in question. 

 It is also suggested that the larvae of another genus, that 

 of Tiresius serra, furnish these hairs ; but, however that 

 may be, it is quite clear that the hairs called " Dermestes " 

 (fig. 307) are not -obtained from the -Bacon-beetle. 



In the Gyrinus, Whirligig, we have a combination of 

 contrivances to facilitate the creature's movements in the 

 element in which it lives. The hind legs are converted 

 into a pair of oars of remarkable efficiency, the point ot 



Fig. 284. 

 1, Leg ot Gyrinus, Whirligig, with paddle expanded. 2, With paddle closed up. 



their connexion with the body being adapted with great 

 precision to ensure the most effectual application of the 

 propelling power ; as it strikes out behind in the act of 

 swimming, a membranous expansion of a portion of the 

 legs enables the insect to move about with great rapidity ; 

 upon the legs being drawn back again towards the body, 



the membrane closes 



up, 



and thus offers but a small 



resistance to the water (fig. 284). The eyes are not the 

 least curious part of the merry little creature ; while one 



s s 



