SEASONAL CHANGES AND HISTORIES. 131 



triple-brooded, yet it appears no earlier than the 

 preceding double-brooded butterfly, namely, be- 

 tween the sixth and tenth of May ; by the middle 

 of June, sometimes by the end of the first week, 

 it has disappeared, and within two months of its 

 first appearance is once more upon the wing ; by 

 the end of July it has again become scarce, 

 though occasional specimens persist until the third 

 generation has made its appearance, about six 

 weeks after the appearance of the second, or about 

 the twentieth of August. Butterflies of this 

 third brood may be found nearly throughout Sep- 

 tember, and doubtless lay their eggs early in Sep- 

 tember, giving the caterpillar time to attain its 

 full growth and change to chrysalis before winter. 



AH these examples have been taken from a 

 single family of butterflies, comprising the hair- 

 streaks, blues, and coppers, to show how differ- 

 ent the histories of allied insects may be. Yet it 

 rarely happens in this family that winter is 

 passed either in the larva or imago state, and we 

 therefore hardly expect to find the complication 

 we may look for elsewhere. Choosing our exam- 

 ples then from all the families of butterflies, we 

 will continue our histories with an eye to further 

 differences. 



Commencing with those which winter as cater- 

 pillars, we may instance the Blue-eyed Grayling 

 [see Figs. 143, 144], which is single-brooded and 



