EASTERN UNITED STATES. 47 



or gregarious, the manner of feeding and place of rest- 

 ing, place and manner in which the chrysalis is formed, 

 manner of depositing the eggs, etc. Such life-histories 

 form a valuable part of our knowledge of these insects. 



Moulting is a critical period in the history of a cater- 

 pillar. To make preparation for it the larva fixes its 

 feet to some object, and after remaining quiet for a time 

 bursts the skin open on the back of the thorax, and 

 through tins opening comes out of its old skin. At 

 first all the external parts are soft and tender, for which 

 reason it is easily injured. Soon the parts harden by 

 evaporation of the water, and the caterpillar then resumes 

 its feeding. During: the time of moulting; it should not 

 be transferred from one vessel to another if it can be 

 avoided. The time of moulting may be known by the 

 enlargement of the neck or second segment, caused by 

 the partial withdrawing of the head from the old skin 

 and pushing it up against this part. 



If the larvae when first hatched are placed in tubes, 

 they may afterwards be placed in a jelly-dish, where 

 they may be kept till of considerable size. The writer 

 has kept several species in jelly-dishes till they were 

 three-fourths of an inch long. From this they may be 

 transferred to the breeding-cage, or vivarium. Some 

 entomologists use a cage made of wire gauze over a frame- 

 work, with a zinc bottom to hold dirt and the food, but 

 these are expensive. The writer has used for a number 

 of years boxes of different sizes with a glass in front for 

 a door, sliding in upright grooves. Upon the bottom of 

 the box is placed two and a half inches of garden-soil and 

 sand, — just enough of the latter to prevent the soil from 

 drying in hard cakes. By wetting the dirt occasionally, 



