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 brandies of the sassafras {Laiirus 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) liave attained 
a sufficient size to aiford 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 
Avith 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 
