266 MOTHS AND BUTTERFLIES. 



As soon as tlie caterpillar is hatched, it spins a little web to cover 

 itself, securing the threads all round to the edges of the leaf, so as to 

 bend upwards the sides and form a kind of trough, in which it 

 remains concealed. One end of the cavity is open, and through this 

 the caterpillar thrusts its head while eating. It begins with the 

 extremit}^ of the folded leaf, and eats downwards, and, as it gradu- 

 ally consumes its habitation, it retreats backwards, till at last, 

 having, as it were, eaten itself out of house and home, it is forced to 

 abandon its imperfect shelter, and construct a new one. Tliis is 

 better tlian the first, for the insect has become larger and stronger, 

 and withal more skilful from experience. The sides of the lai'ger 

 leaf selected for its new habitation are drawn together by silken 

 threads, so that the edges of the leaf meet closely and form a light 

 and commodious cavity, which securely shelters and completely con- 

 ceals the included caterpillar. Tliis in time is eaten like the first, 

 and another is formed in like manner. At length the caterpillar 

 having eaten up and constructed several dwellings in succession, and 

 changed its skin three or four times, comes to its full size, leaves off 

 eating and seeks a suitable place in which to undergo its transforma- 

 tions. The young caterpillars are almost black ; the full-grown 

 ones measure about one inch and a half, are generally of a brown 

 color more or less dotted with white, with a l)lack head, rough with 

 elevated white points, with white biunching spines on the l)ack, and 

 on each side there is a row of yellow crescents. The chrysalis is 

 gray, with a whitish bloom upon it like that on a plum, and the 

 little pointed tubercles on its back are gohl colored. The clnysalis 

 state continues about ten days, or longer if the weather be cool and 

 wet." 



The caterpillars of this butterfly are frequently so al)undant as to 

 almost strip the leaves from the nettles, and being protected as they 

 are from the sight of their enemies one would naturally think that 

 their chances of life in the struggle for existence were very good. 

 However, if a number of the full-grown larva? are collected and ex- 

 amined, one will soon see the eggs of the ichneumon flies, for these 

 parasites have very sharp eyes and even in liis curled-leaf liome the 

 caterpillar of Pyrameis atalanta is not exempt from the fate that 

 awaits ninety-nine one-hundredths of his relatives of other species. 



A butterfly having almost a world-wide range is Pyrameis cardui. 

 This insect has succeeded in establishing itself over Euro})e, Asia, a 

 good part of North and Soutli America and the Sandwich Islands, 



