246 THE LIFE OF AN INSECT. 



were dead. He imagined, with great probability, 

 that the cause of their death was the evaporation 

 of their fluids, which of course does not take place 

 when they are enshrouded in their cocoons, and 

 surrounded on all sides with water. He made 

 one more experiment with them, which was as 

 follows : He took several out of their cocoons, and 

 placed them in water in such a manner, that one 

 of their sides was in the air, while the other was in 

 the water ; he kept them for a considerable time 

 in this position, and he had the pleasure at its 

 expiration of seeing them become perfect insects, 

 just as if they had never left their cocoons. The 

 necessity of both air and water to their well-being 

 was thus clearly proved. 



How can we sufficiently admire the ingenuity 

 and skill displayed by this insect in the execution 

 of its difficult task! When a human engineer 

 wishes to build under the water, he must have 

 recourse to the most cumbrous and powerful 

 mechanism to enable him to effect his object. 

 Piles must be driven into the bed of the river so 

 closely as scarcely to allow any water to come 

 through; a steam-engine must be fixed close by, 

 to pump out all the water from the space thus 



