300 THE LIFE OF AN INSECT. 



notice them at the proper period, the afternoon of 

 a warm sunny day, we were astonished the next 

 morning to find a surprising number of pupa skins 

 lying empty of their tenants on the surface, as 

 though some of the water fairies enumerated in 

 fable had been dancing on the waves all night, and 

 left their little black shoes behind them in their 

 haste to flee from the light of the smiling morning. 

 We determined to be better prepared for the ob- 

 servation on that day; and as the afternoon came we 

 had the gratification of seeing a large number of 

 these insects rise from the water, all in the follow- 

 ing*" manner: They rose up from the bottom and 

 reached the surface by the peculiar movement of 

 their tails just described; there the thorax was 

 thrust above the water, and immediately the in- 

 sect burst its cerements, elevated itself by a wave- 

 like motion from the rest of the pupa case, which 

 filled with air, and now glistened like silver; it 

 then planted its forelegs on the water, withdrew 

 the rest of its body from the case, unfolded its 

 wings, and in a few moments was sailing in the 

 thin air. On one stormy day the surface of our 



* This scene is represented in the Frontispiece to Part III. 



