A FROZEN WORLD 



223 



of these widening waves is almost as interesting at 

 times as the astonishing velocity and certainty of 

 movement in the beetles themselves. So, all sum- 

 mer long, they continue their wild career, seeming 

 to earn their livelihood easily by amusing them- 



NO . g. WHIRLIGIG BEETLES IN WINTER, SLEEPING. 



selves. But as soon as winter approaches, a change 

 comes o'er the spirit of their dream. They retire 

 to the depths, as you may observe in No. 8, and 

 bury themselves in the mud while the pond is 

 frozen over. During this period they indulge in 

 a good long nap of some five or six months, and, 



