BUTTERFLIES 75 



they seemed to become aware of the mistake they 

 had made, and sat with gaping mouths rolling 

 their tongues about until they had got quit of the 

 nauseous caterpillars, which seemed perfectly un- 

 injured and walked off as briskly as ever." 



Terrifying colours are also met with ; in the 

 caterpillars of the puss moth and hawk moth the 

 eye spots are of this nature, and the caterpillar of 

 Bombyx regia, the " hickory horned devil " of the 

 Southern States of North America, is ornamented 

 with an immense crown of orange-red tubercles 

 which if disturbed it erects and shakes from side 

 to side in a very alarming manner, the negroes 

 believing it to be as deadly as the rattlesnake, 

 whereas it is really perfectly harmless. 



The pupa, or chrysalis, is the last stage of 

 existence of the caterpillar. The change from 

 caterpillar to butterfly is an enormous one, not 

 merely as regards the possession of wings, but 

 as regards the whole organisation ; the mouth, 

 the digestive system, the nerves, the eye and all 

 parts being most profoundly modified. The chry- 

 salis period is the stage of rest, and constitutes 

 a protected condition in which these changes can 

 be effected. This stage sometimes lasts a few 

 weeks or even days only, sometimes months or 

 during a whole winter. In the case of the small 

 eggar moth, insects of the same brood appear a 

 few at a time each year up to fourteen or fifteen 

 years. Now the time of appearance of the moth 

 being February, it is obvious that in a severe 

 winter the whole brood might be killed off if they 



