THE INSECT WORLD. 



Fig. 216. Larva, pupa, cocoon, :ind moth of Bombyx mori. 



development of the imago is an operation which is called the ttoujftagc, 

 or stifling. 



To effect this stifling, the cocoons are exposed to a high tem- 

 perature. Formerly, in the Cevennes, the cocoons were placed in a 



