MOTHS AND BUTTERFLIES. 



455 



the cell. The hind wing is sliaded with purple next the body, with two curved, dark 



purple bonds within the outer border. In the middle of the wing is a large, round, 



blue spot with a whitish centre, enclosed in a 



broad ring of brownish black. The females 



differ in having the fore wings suffused with 



purplish brown and the usual lines quite light. 



The cream-colored eggs, marked with oi'ange 



and brown, are laid in clusters of thirty or 



more on the underside of the leaves, and hatch 



in about twelve days. The young caterpillars 



are one-eighth of an inch in length, of a reddish 



color, and covered with long bristles. They are social in their habits until half-grown, 



feeding and moving about in regular ranks, but when larger they se])arute, and wander 



about feeding alone. When mature they are about two inches and a half in length, 



of a delicate pale-green color, somewhat paler along the back, with a broad, dull-wliite 



stripe, margined with reddish lilac, on each side. They have several clusters of green 



branching spines, tipped with black, on each segment. These spines are very sharp •, 



and when the insect is carelessly handled they sting severely, producing an irritation 



similar to that of a stinging nettle. After the caterpillars are done feeding they 



Tolype vidtitUi. 



Fig. 574. — Eacles a 



descend to the ground, where they draw together a few dried leaves, within which 

 they spin a cocoon of tough, gummy, brown silk, and remain in the pupa state during 

 the winter. This species has quite a varied appetite, feeding freely on a large number 

 of plants, such as apple, thorn, Avillow, elm, oak, corn, cotton, and clover. 



The grouji of moths in this familj', called Attaci, includes some of the largest as 

 well as the most valuable silk-producing species. 



The Pernyi silk-worm, Attacus pernyi, an oak-feeding species, was first introduced 

 into France from northern China in 1850 ; and it has since been brought to this country, 

 where its cultivation gives much promise of success as a silk-producing moth. The 

 brownish, globose eggs are said to hatch in eight or ten days after they are laid, and 

 the young caterpillars are of a chocolate-brown color, with reddish tubercles, on which 

 .are reddish bristles. The color changes with each moult ; and the mature caterpillar 

 is of a dark green color, with a faint reddish line along each side. The head and feet 



