OF THE FARM AND GAKDEK. 



179 



of the body are but poorly developed, and consist of but 

 slight wart-like projections; they are furnished, however, 

 with numerous small hooks, which answer an admirable 

 purpose, in enabling the bearer to cling to his home-spun 

 coat, which shelters him from the weather, and defends 

 him from his enemies, and which is even more essential 

 to his existence than are the clothes we wear to ours. 

 The worms do not arrive at their full-grown condition 

 without passing through critical periods. At four dif- 

 ferent times during their growth they close up the mouth 



Fig. 113. BAG, BASKET, OR DROP-WORM. 



(Thyridopteryx epTiemerceformis, Haw.) 



a, Larva ; 6, Chrysalis ; c, Female ; d, Male; <?, Female bag opened ; /, The Worm 

 and its Bag ; ,g, The Young. 



of their bags, and retire for two days to cast their skins 

 or moult, as is the nature of their kind, and they push 

 their old skins through a passage which is always left 

 open at the extremity of the bag, and which also allows 

 them to throw out their excrement. 



During their growth they are very slow travellers, and 

 seldom leave the tree on which they were born; but 

 when full grown, they become quite restless; and it is at 



