THE PIERIDS 



when a chryfalis refembles the bark to which it 

 is fixed ; or a caterpillar the flower or leaf it feeds 

 upon ; but that purpofe feems not to be anfwered 

 here. Do fuch fimilarities of appearance, in 

 ferving to exercife the attention and powers of 

 difcrimination of animals deftined to devour the 

 fly, or of others that feed upon the flower, thus 

 increafe the general fum of happinefs in conse- 

 quence of the employment of intellect and the 

 fuccefs of its exertion ? " 



The cloudless sulphur is most socially inclined, 

 congregating in great numbers on flowers and 

 forming a moving mass of brilliant yellow under 

 the rays of the hottest, brightest sunshine. But 

 the most interesting of its habits is that of mi- 

 grating in flocks from southeast to northwest 

 in the spring and from northwest to southeast 

 in the autumn. A stream of them "six or eight 

 yards wide and about as many high " was once 

 observed near Charleston. Another record in 

 Georgia mentions "a half a dozen visible all the 

 time pursuing an undeviating course, flying over 

 and not around houses and obstructions." An- 

 other observer has witnessed the autumn migra- 

 tion for twenty-six consecutive years. 



The species is double-brooded, and is usually 

 abundant in the Southern States and migrates 



