910 THK BUTTERFLIES OF NEW EN(;LAK1). 



lar to rcaeli nmtuiity, and the period of tlie chrysalis, aud in these 

 hibernating butterflies \vc shall rarely Hiid that these stages together 

 occupy on the average more tlian two months. Tlie remaining ten 

 months must therefore be the average time s[)ent ujion the wing. That 

 many may li\o eleven months or even twelve seems probable, for a but- 

 terfly may contiiuic to fly for some time after the first eggs are laid, 

 especially in the case of those which lay but one at a time, where the eggs 

 do not develop in the ovaries at once, but slowly and by degrees, and so 

 are deposited in succession over a considerable period of time. 



In an article in the C'anadi;in Entomologist on this subject, Mr. ^\'. H. 

 Edwards has labored to show that eggs are almost invarialdy laid by but- 

 terflies fresh from the ciirysalis. and that the butterfly dies soon after 

 the laying of the eggs. This proves quite too much, for if it were so, a 

 buttei-fly would hardly fly more than a week. That eggs are often laid by 

 butterflies soon after eclosion from the chrysalis is doubtless true, but 

 there are quite as many cases, where egg laying is delayed for a consider- 

 able length of time, — two, three or four weeks : an e-\aniination of the 

 ovaries of butterflies will show that it is rarely the case that all the eggs 

 are laid even within two or three days of each other, but that they mature 

 by degrees too slowly for such rapid oviposition. There are of course 

 some, in which the eggs are laid in masses, when a greater number are 

 laid in a single day, but the cases are fiir more numerous where egg lay- 

 ing is continued over many days, and sometimes jjrobably over several 

 weeks. 



It is possible that the duration of the life of butterflies is gi-eater in 

 the north than in the south. As one approaches the tropics, insectivorous 

 birds and other creatures are far more destructi^'e of butterfly life than 

 with us, and the chance of long life upon the wing must be greatly less- 

 ened with the niunerous liabilities to disaster which overtake the poor 

 butterfly in the warmer regions. There may even be a difltn-ence in this 

 respect between districts so near each other as West Virginia and New 

 England. For certainly my own experience of the overlapping of broods 

 of difl'erent butterflies as seen by me in New England is ■s'cry difterent 

 from that reported by Mr. Edwards in West Virginia, and inasmuch as 

 these broods follow each other witii greater rapidity in Virginia than 

 with us, the difference is thereby exaggerated. 



To judge from the statistics that I have collected from observations 

 made in the field both by myself and numerous correspondents, I am in- 

 clined to think that, in the case of those butterflies which are born and die 

 the same season, the average length of life of the mass of them, that is, 

 omitting mention of those which, cut off early, come to an imtimely end, to 

 be not far from four to five weeks, varying in different species from three 

 to six or seven. Of course it is impossible to arrive at any very ac- 



