THE TRIBE OF THE CRESCENT-SPOTS 143 



it is probable that in many localities the species is both 

 single-brooded and double-brooded. In such a case some 

 of the caterpillars go into hibernation probably about mid- 

 summer, remaining quiescent through the later weeks of 

 summer and all the weeks of fall and winter, w^hile others 

 would matme to chrysalids and butterflies in summer, and 

 the butterflies would lay eggs for a second brood of larvae 

 which would hibernate when partially grown. There are 

 opportunities for careful observers to do good work upon 

 the life-history of this species in many parts of its range. 



The Pearl Crescent 



Phyciodes iharos 



Some years ago Mr. Samuel H. Scudder, the most not- 

 able student of New England butterflies, wrote a delightful 

 essay with the title "Butterflies as Botanists." From his 

 long experience in rearing the eggs of these insects he con- 

 cluded that the egg-laying females know in a most remark- 

 able way the precise kinds of leaves upon which to ovi- 

 posit. He educed many illustrations in proof of the fact 

 and quoted a remark of Asa Gray, the most eminent of 

 American botanists, that is worth repeating. At that 

 time Scudder had reason to believe that the Pearl Crescent 

 laid its eggs exclusively upon the New England aster. 

 Now the asters as a group have been a source of much 

 trouble to the botanists who have attempted to classify 

 them as to species and variety. The various forms are so 

 similar to one another that different authorities have not 

 agreed as to the limitations of the species . So when Gray was 

 told that this little butterfly was able always to distinguish 



