134 SEASONAL CHANGES AND HISTORIES. 



Take next our commonest yellow butterfly, the 

 Clouded Sulphur, familiar to every one [see Figs. 

 102, 103]. The first brood of butterflies, which is 

 also the least numerous, appears about Boston, 

 on warm sunny hillsides, sometimes as early as 

 the twenty-fourth of April, sometimes not until 

 toward the middle of May, the advent of this in- 

 sect being more than usually affected by the sea- 

 son. Toward the end of May it becomes very 

 abundant, then begins to diminish in numbers, 

 until only a few rubbed females remain when the 

 next brood appears ; the females begin to lay 

 eggs very soon after birth, the eggs hatch in five 

 days, and the caterpillars often attain their full 

 growth in three weeks, while the chrysalis state 

 lasts from nine to eleven days. The appearance 

 of the second brood is varied, like the first, ac- 

 cording to the latitude ; in the vicinity of Boston 

 it usually appears during the first week in July ; 

 the caterpillars of this brood mature quite as 

 rapidly as those of the previous, and numbers of 

 the butterflies are sure to be on the wing at the 

 advent of the third brood, which is occasionally 

 as early as mid- August, but often is delayed until 

 September ; the butterflies of this last brood are 

 still numerous in the middle of October, and con- 

 tinue flying until after the first severe frost ; some 

 have even been seen in the neighborhood of Bos- 

 ton as late as the middle of November. As the 



