6 4 



ELEMENTARY ENTOMOLOGY 



FIG. 83. The spiny elm caterpillar, or mourning cloak 

 butterfly. (Slightly reduced) 



Partly grown caterpillars, chrysalis, empty chrysalis, and adults. 



(After Britton) 



wherever it goes, 

 so that the many 

 threads soon make 

 a fine silken car- 

 pet, which serves 

 as a foothold. At 

 the end of a week 

 they molt ; the skin 

 of each caterpillar 

 splits down the 

 back, and it crawls 

 out with a new and 

 larger skin, which 

 has been forming 

 beneath the old 

 one. The caterpil- 

 lars remain quiet 

 during molting, 

 but they soon be- 

 come active again 

 and feed with in- 

 creased voracity. 

 Every week for the 

 next three weeks 

 this molting proc- 

 ess is repeated, 

 the cast skins 

 decorating the de- 

 foliated twigs, as 

 shown in Fig. 84. 

 As they grow, the 

 caterpillars scatter 

 over the neighbor- 

 ing leaves, but still 

 remain in colonies. 

 Their appetites 

 seem to increase 

 as they grow, and 



