INSECTS IN THEIR PERFECT STATE. 131 



The common Cabbage Butterfly, Pieris Bras- 

 sicce, and the large Goat Moth, Cossus Ligniperda, 

 both live about three weeks in their perfect state, 

 though their length of life in the larva stage is so 

 different ; that of the Moth being two, and some- 

 times three years, while the larva of the Butterfly 

 lives about as many weeks. 



The female Moth, or Butterfly, generally expires 

 the moment she has laid her eggs, but it is said that 

 by keeping the sexes apart their existence may be 

 considerably prolonged. Several kinds, however, 

 such as the " Peacock," the." Small Tortoise-shell," 

 the "Bed Admiral," and some otbers, naturally 

 live through the winter when they are of late au- 

 tumnal broods. 



The change of the Beetle from the larva to the per- 

 fect state is much less striking than that of the But- 

 terfly, though the metamorphosis may be considered 

 very complete. After it has made its cocoon, or 

 sought the proper place to undergo the change, 

 however, the alteration of form is so gradual that 

 it can scarcely be considered to assume a special 

 pupa form like the Lepidoptera, in their chrysalis. 

 The larva of the Beetle, when the change com- 

 mences, becomes gradually shorter, the wing-cases 

 and wings begin to appear, and the legs, antennae, 



