CHARACTERS OF A PUPA. 227 



nised so as to say that they were pupae, or perfect 

 insects, even by tolerable entomologists ; and it is 

 very likely that mistakes of this kind have often 

 occurred.* We learn, therefore, from this state- 

 ment, that some pupae are active, and move about 

 just as they did before, although they are in the 

 pupa state. 



In a great number of cases, then, a pupa is a 

 state in an insect's life when it rests from active 

 exertion, and from taking food, and when, under- 

 neath the dry and withered skin, a series of great 

 changes are taking place, which are preparing it for 

 its future life in the perfect state. Thus it differs 

 from the larva state in not eating and moving, and 

 in the important particular, that it is receiving 

 new parts and organs, which are added to it under 

 the skin. It also differs from the perfect insect in 

 the same respects as in the first place from the 

 larva, and also in the important circumstance, that 

 the perfect insect the moment it enters that state, 

 has no more organs added to it it is, in fact, 

 perfect, while the pupa is imperfect. Let us place 

 these differences in a tabular form : 



* Mr. Blackwall has discovered that by carefully examining 

 ihefeet of spiders, this mistake may be avoided. 



