50 THE CANADIAN ENTOMOLOGIST. 



ovaries at once, but slowly and by degrees, and so are deposited in suc- 

 cession over a considerable period of time. 



In an article in the Can. Ent. (xiii., 205-214) on this subject, Mr. W. 

 H. Edwards has laboured to show that eggs are almost invariably laid by 

 butterflies fresh from the chrysalis, and that the butterfly dies soon after 

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

 butterfly 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 examination of the 

 ovaries of butterflies will show that it is rarely the case tliat 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 far more numerous when egg laying 

 is continued over many days, and sometimes probably over several 

 weeks. 



It is possible that the duration of the life of butterflies is greater in the 

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

 birds and other creatures are far more destructive of butterfly life than 

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

 ened with the numerous liabilities to disaster which overtake the poor but- 

 terfly in the warmer regions. There may even be a difference 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 different butterflies as seen by me in New England is very different 

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

 these broods follow each other with 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 

 dje 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 untimely 

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

 from three to six or seven. Of course it is impossible to arrive at any 

 very accurate determination regarding this, since in the case of any par- 

 ticular species we are obliged to base our conclusions on observations of 



