56 GENERAL ZOOLOGY 



passes the winter in the South, like our migratory birds, 

 and with approaching warm weather the different individ- 

 uals slowly work their way northward, the females laying 

 eggs in different places in the course of the journey. The 

 eggs are pale green and are deposited singly on the leaves 

 of the different species of milkweed. In about four days 

 the eggs hatch into caterpillars (Fig. 38), which imme- 

 diately proceed to devour the eggshells. For the rest of 

 their larval existence the caterpillars are voracious feeders 

 on the leaves of the milkweed. They grow for two or three 

 weeks, molting several times as they increase in size, till 

 they are conspicuous objects, nearly five centimeters (two 

 inches) long, prominently banded with yellow and black 

 (Fig. 38). When through feeding, each larva spins a pad 

 of silk on some convenient support and, molting once more, 

 appears in a mummy-like pupal condition (Fig. 38), at- 

 tached by hooks at its extremity to the pad of silk spun by 

 the larva. In the inactive pupal stage the milkweed butter- 

 fly is bright green with golden spots. To this, and to some 

 of the other naked pupae of butterflies, the name chrysalis 

 is given. The insect remains in the pupal stage for ten or 

 twelve days, when the skin splits (Fig. 39) and the butter- 

 fly comes out with crumpled wings, which soon expand and 

 harden. 



The monarch butterfly possesses remarkable powers of 

 flight. Mr. Scudder, in his Guide to Butterflies, states that 

 it has been seen at sea five hundred miles from land, and 

 that it has within thirty years spread over nearly all the 

 islands of the Pacific, and even to Australia and Java. 



It is asserted that these butterflies, although so brilliantly 

 colored and conspicuous, are not fed upon generally by 

 birds and other animals which might use them for food, 

 owing to their possessing a strong odor which renders them 

 distasteful. If this is the case, the distinctive coloration 



