106 THE BUTTERFLY VIVARIUM. 



they may be divided into three tolerably distinct 

 classes: — 



First, those which so closely resemble the larva 

 stage, that the precise time of transition is scarcely 

 perceptible. 



Secondly, those partially resembling the larva, 

 but having rudimental wings appearing more con- 

 spicuously than in the preceding state. 



Thirdly, those in which the form of the larva 

 entirely disappears in the case or perfect chrysalis, or 

 becomes a form of the nymph kind. 



Or they may be divided into two divisions only ; 

 those which are active during the pupa or nymph 

 stage, as Grasshoppers, etc., and continue to eat ; 

 and those which sink into a partly dormant state, 

 as those of Butterflies and Moths, certain Beetles, 

 Dragon-flies, etc. 



Within the case, the pupa itself exhibits, at a 

 comparatively early stage of its progress, nearly all 

 the parts of the perfect insect very distinctly. 

 In such pupa cases as those of the Dragon-fly, 

 Avhich enclose each principal member separately, the 

 eventual forms quickly assume, with the exception 

 of the wings, nearly their full proportions and 

 natural position, though in a soft state. In the 

 complete chrysalis, where all the members are tightly 



