MOULTING OF SILKWORMS. 37 



about five or six days' feeding, and then the worms 

 will begin to sicken for their first moult, or casting 

 the skin. Silkworms have four of these moults, 

 at each of which they appear to suffer pain or 

 inconvenience ; they also entirely leave off eating 

 for two or three days. The caterpillars at that 

 time raise the fore part of their bodies, and show 

 tokens of uneasiness. They have grown rapidly, 

 and their skins, not having grown in proportion, 

 now appear to press and inconvenience them; 

 but after two or three days fasting, they become 

 thinner and are able gradually to rid themselves 

 of their skin. It is now that their owner may see 

 the use they begin to make of their silk. By 

 watching them closely he sees each caterpillar 

 throw out a number of very fine silken lines, by 

 which it fastens the skin to one spot. Having 

 done this, it is able to creep out, without dragging 

 the skin about after it, as would otherwise be the 

 case. In this operation the whole covering of 

 the body, including that of the feet, of the jaws 

 and teeth, is cast off; but it sometimes happens 



