130 BUTTERFLIES 



h^e for hastening the earhness of the broods so that the 

 hibernating caterpillars might either become larger or 

 might go into the hibernating condition earlier than those 

 of Group A. 



In Group C, the variation takes place in the larvae rather 

 than in the butterflies. These may go on in the normal way 

 up to the time the caterpillars of the summer brood become 

 half grown. Then they become lethargic, ceasing to feed 

 and to all appearances going into hibernation. They re- 

 main in this condition until the following spring when they 

 come forth from their winter's sleep and feed upon the 

 violets in precisely the same way as the caterpillars of the 

 third brood of Groups A and B. 



In Group D we have another interesting variation of the 

 larvae. These are the same as C up to the time of be- 

 coming lethargic, that is, the larvae of the summer or 

 second brood become lethargic at the same time as those of 

 Group C but instead of continuing in this condition until 

 the following spring they remain in lethargy only three or 

 four weeks, then they wake up (having apparently then 

 changed their caterpillar minds) and begin to feed, soon 

 maturing and changing to chrysalids from which butterflies 

 emerge late in September or early in October. The result 

 is that these butterflies lay eggs so late that the cold nights 

 come on apace and the little caterpillars apparently 

 take no food at all but go into hibernation immediately. 

 In consequence these must eat for a longer period the 

 following spring, so that the butterflies into which they 

 mature will be likely not to appear until well along in 

 June. 



It is probable that even this rather elaborate statement 

 does not do justice to all the variations in the development 



