158 THE LIFE OF AN INSECT. 



take place if we treat larvse in the same manner ; 

 from which we learn that undoubtedly breathing- 

 is not only one of their functions, but a most 

 necessary and important one. 



This may be easily proved. If the reader will 

 procure about a dozen caterpillars of any common 

 kind, and put them into a dry phial, corking them 

 closely up, and if he leaves them in their prison of 

 glass a sufficient time, all will die, even though he 

 may have supplied them, on putting them in, with 

 an abundance of food. Clearly, therefore, they do 

 not die of starvation, and we should be naturally 

 disposed to say they must have died of suffocation ; 

 that is, they died because the function of breathing 

 could not take place, as there was not the neces- 

 sary change of the air contained in the phial. But 

 suppose that other caterpillars were procured and 

 put into another phial, with a sufficiency of green 

 food, the mouth being covered over with a piece of 

 muslin, or fine lace, what would then be the result ? 

 Simply that they would live and thrive for as long 

 a period as they received their proper quantity and 

 quality of food, and would pass through all their 

 stages of existence as comfortably as if in the open 

 air. The reason would be because the open fibres 



