136 HYALOPHORA PROMETHEA. 



of this moth: — " During the present year (1833), 

 this beautiful moth will be unusually abundant in 

 the vicinity of Philadelphia, judging from the num- 

 ber of cocoons which are to be seen hanging from 

 the branches of the sassafras (Laurus sassafras) 

 and spice- wood (L. benzoin). The casual observer 

 would no doubt suppose them to be merely withered 

 leaves that have withstood the blasts of winter, for 

 such they were evidently intended to resemble, by 

 the little architect, when preparing its narrow cell. 

 The naturalist, however, is not to be thus deceived, 

 as a boy and myself collected from three to four 

 hundred specimens during short winter rambles in 

 the neighbourhood. 



" The perfect insects appear about the end of 

 May and beginning of June, at which time the 

 leaves of the sassafras, spice-wood, and swamp but- 

 ton-wood (Cephalanthus occidentalis) have attained 

 a sufficient size to afford a plentiful supply of food 

 to the caterpillar ; the parent insect most commonly 

 selecting those trees for the sustenance of her future 

 progeny, and depositing her eggs on or near the 

 leaves which have been chosen for that purpose. 



" The caterpillar casts its skin three or four 

 times, increasing in bulk and brilliancy of colour 

 with each change, and finally attains the size repre- 

 sented in the figure; it then loses the voracious 

 appetite which had hitherto been its predominant 

 character, and begins its preparations for the great 

 transformation it is to undergo, by selecting a per- 

 fect leaf, the upper surface of which it covers with a 



