168 BUTTERFLIES 



along with it one of the most beautiful of our butterflies 

 which has received various scientific names and the com- 

 mon name of the Painted Lady, although it is also often 

 called the Thistle Butterfly and the Cosmopolite, which 

 latter title perhaps is to be preferred. This butterfly, 

 however, can scarcely be considered a troublesome en- 

 emy of its host plant, for it is seldom sufficiently abundant 

 to injure the thistle appreciably. The relation between 

 the two is rather suggestive of that mutual toleration by 

 which two living things develop together with advantage 

 at least to one and without serious disadvantage to the 

 other. The universal distribution of the food plant has 

 led to a like distribution of the butterfly. Consequently 

 the Thistle butterfly has long been recognized as the most 

 cosmopolitan species of its group. (See plate, page 176.) 



Aside from the wide distribution of its food plant and 

 possibly correlated with it through the diversity of cli- 

 matic conditions under which the insect has developed, 

 this butterfly is remarkable for its powers of flight. Many 

 instances are known where it has been taken at sea long 

 distances from land. This is due not only to the pro- 

 pensity of the individual for taking aerial journeys, but 

 also to the fact that this is one of the butterflies which has 

 the instinct to congregate in swarms and to migrate long 

 distances when thus congregated. In 1879 such a flock 

 started from Africa and migrated to Europe. 



One of the most remarkable things about this butterfly 

 is our ignorance of what it does with itself in winter. 

 American entomologists are agreed that the adult butter- 

 fly hibernates, but where it does so seems not to be 

 known. Here is an excellent opportunity for some young 

 naturalist to go scouting, hunting in board piles, under 



