INTRODUCTION. XXXI 



which insects pass through before assuming the perfect state. 

 In insects with perfect metamorphoses, including Butterflies 

 and Moths, this state is always inactive. Many pupae of But- 

 terflies have a gilded appearance, and such a pupa has been 

 styled a " chrysalis " or " aurelia," terms derived from the Greek 

 and Latin, which express this peculiarity, and which have since 

 been applied to all Lepidopterous pupae, whether gilded or 

 not. But the term "Aurelia" is no longer used, and will 

 not be found in recent works on entomology, though eighty 

 or a hundred years ago collectors of Butterflies and Moths 

 were generally called " Aurelians." 



The caterpillars of Butterflies generally fix their pupae on 

 or near their food-plants, and a large number suspend them- 

 selves by the minute hooks with which the narrow end of the 

 body is provided, to a little button of silk, and thus hang 

 freely by the tail. These are the Nymphaiidcc ; but in most 

 of the other families the pupa is attached by the tail, but fixed 

 in an upright position, being supported by a belt of silk round 

 the body. Some of the Satyrince occasionally place their 

 pupa? close to, or perhaps even on, the surface of the ground, 

 and the Skippers, and the species of Pamassius, a genus of 

 Alpine Butterflies which includes the well known Apollo Butter- 

 fly, form slight cocoons. 



Moths are much more varied in their mode of forming th Jr 

 pupae. Many are formed under the surface of the ground, 

 some being naked, and others enclosed in a cell of aggluti- 

 nated earth. Tree-feeding caterpillars often form their cocoons 

 in the chinks of the bark, or in the earth close to the root of 

 the tree on which they have fed. The conspicuous tough 

 boat-shaped cocoons of yellow silk, formed by the Burnet 

 Moths, are very common in meadows, attached to btalks of 

 grass. Many of the large ocellated Silkworm Moths allied to 

 our Emoeror Moth form their cocoons between leaves 0:1 the 



