Classification of Insects. 107 



other insects, by the different structure of their various legs, 

 and by the decided distinction which is introduced between 

 the head and body. Moreover, their skin is variously co- 

 loured, and provided with a most astonishing diversity of 

 external appendages. 



At first, these animals are voracious in their habits. Pro- 

 vided with powerful jaws, they chew large quantities of food, 

 mostly derived from the vegetable kingdom. But before they 

 undergo their metamorphosis into pupse, before casting the 

 last skin of the caterpillar, the young Lepidoptera begin to 

 form their wings, which grow out of the second and third 

 ring of the thorax in the shape of short, folded bags, very 

 similar indeed to the first rudiments of wings in Neuroptera. 

 These appendages rapidly enlarge, and when the caterpillar 

 casts its skin, they have already attained a considerable size. 

 But, instead of remaining free, they are soldered to the body 

 of the pupa, the outer wings become hard, and form what 

 have generally been called the wing-covers, resembling then 

 very much the wings of Coleoptera. But the jaws have un- 

 dergone greater changes. They are now transformed into 

 long appendages, similar to the articulated threads which 

 constitute the sucking apparatus of Hemiptera and some 

 Diptera. The resemblance of the jaws of Lepidoptera at this 

 period to those of Hemiptera is so great, that we may truly 

 say, that the form of this apparatus in the pupa completely 

 exemplifies the permanent structure of the sucking apparatus 

 in Hemiptera; and the hardness of the wing-covers reminds us 

 at the same time of the hardness of the base of the upper 

 wings in the greater part of Hemiptera ; so that Hemiptera, 

 in their perfect condition, would correspond to the earliest 

 condition of the pupae of Lepidoptera. So the higher degree 

 of locomotive power of these parts in Diptera would remind 

 us of the condition of the jaws in the Lepidoptera, at the 

 moment that the perfect butterfly leaves its pupa, when the 

 pieces of the mouth move independently of each other, as 

 is the case with the piercers of most Diptera, which remain 

 free, while in Lepidoptera they finally form the articulated 

 proboscis. This type of jaws of the Diptera, intermediate be- 

 tween those of Hemiptera and the perfect Lepidoptera, would 



