FINAL CHANGES OF THE PUPA. 271 



of the day or month when this state is ended, 

 and the perfect state is entered upon ; but a 

 limit, nevertheless, exists, mainly dependent for 

 its appointment upon the external influences of 

 warmth and air. 



This limit attained, we are brought to the next 

 point in the history of the insect pupa. The beau- 

 tiful organization of the perfect insect has been 

 going on under the dry and repulsive exterior. Its 

 delicate limbs, exquisitely wrought wings, and the 

 other most wonderful organs with which the 

 perfect insect is furnished, are now completed. 

 Nothing remains but to cast off the slough of its 

 pupa case ; and it will then be set free to range 

 whither it will in the great atmosphere into which 

 it will emerge. If the reader has been watching 

 these insect changes with the natural object before 

 him, he will immediately confirm our statement, 

 when we mention that it is often possible to tell 

 when the pupa case is about to disclose its oc- 

 cupant. The general form of the limbs is often 

 very clearly to be seen, and the movements of the 

 included insect become much more sensible and 

 conspicuous. If the beautiful gilded pupse, called, 

 as we have before said, Chrysalides, or Aurelice, have 



