236 



THE INSECT WORLD. 



Fig. 216.— Larva, pupa, cocoon, and moth of Bombyx 



development of the imago is an operation which is called the ct outage, 



or stiflino:. _ ^ 



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



perature. Formerly, in the Ce'vennes, the cocoons were placed in a H| 



