178 INJUEIOUS INSECTS. 



mother sewed fig-leaves together. The follicle of our 

 Bag-worm is covered by the leaves and stems of those trees 

 or shrubs on which it subsists ; and when evergreen leaves 

 are used they are often very regularly and prettily 

 arranged after the fashion of thatching. 



Throughout the winter, the weather-beaten bags of 

 this insect may be seen hanging from almost every kind 

 of tree; upon plucking them at that season many of them 

 will be found empty, but the greater proportion of them 

 will, on being cut open, be found partly full of soft yellow 

 eggs. Those which do not contain eggs, are the male 

 bags, and his empty chrysalis skin is generally found pro- 

 truding from the lower end. From the middle to the end 

 of May, in the latitude of St. Louis, these eggs hatch 

 into little active brown worms, which, from the first mo- 

 ment of their lives, commence to form for themselves cov- 

 erings. They crawl on to a tender leaf, and attached by 

 the anterior legs, with their tails hoisted in the air, they 

 each spin around themselves a ring of silk, to which they 

 soon fasten bits of leaf. They continue adding to the 

 lower edge of the ring, pushing it up as it increases in 

 depth, until it reaches the tail, and forms a sort of cone, 

 as represented in fig. 11.3, g. As the worms grow, they 

 continue to increase their bags from the bottom, until the 

 latter become so large and heavy that the worms allow 

 them to hang, instead of holding them upright, as they 

 did when they were young. By the end of July, the 

 worms acquire their full growth, when they present the 

 appearance of figure 113, /. At this stage, on being 

 pulled out of its bag, or follicle, the worm appears as at 

 fig. 113, a, that portion of the body which is always 

 covered by the bag, being soft, and of a dull, smoky- 

 brown, inclining to reddish at the sides; while the three 

 anterior, or thoracic segments, which are exposed when 

 the insect is feeding or marching, are horny, and mottled 

 with black and white. The prologs on the hidden part 



