1899] ENTOMOLOGICAL SOCIETY. 79 



or were they the progeny of hybernatora 1 Then from how far south had they come 1 

 Again I have seen specimens haunting a particular locality for weeks, and as far as I 

 could judge by their gradually faiing colors they were the same individuals ; had these 

 permanently settled down in that locality, to go no further north 1 Again, I have seen 

 them flying plentifully for six or eight days and then begin to pair ; indicating that these 

 particular individuals had not laid eggs before reaching that locality. I have seen fresh- 

 looking specimens flying at the time the new brood was emerging from the chrysalis, and 

 so fresh as to give rise to a difference of opinion, as to whether they were previous arri- 

 vals or bred on the spot 1 I have seen quite small caterpillars on the milkweeds when 

 others had passed into the mature state ; all of which have convinced me that there is 

 more than one wave of migration northward during the breeding season. 



These statements prove nothing, but they will help to indicate where the missing 

 links are situated, which yet require to be forged to complete the chain of the life history 

 of this particularly interesting; creature ; and will serve as a guide to those who are 

 inclined and have the opportunity, to continue the observations, and make the evidence 

 positive rather than presumptive. 



Ever since the season of 1894, when I first discovered tlat the upper and under 

 membranes of a butterfly's wing could be separated from each other, my desire has been 

 to make further investigations in the matter, so as to prove or disprove what I thought I 

 learned at that time. Then with the appearance in abundance of Anosia Archippus in 

 the early season of 1899 I fondly hoped that my opportunity had arrived. The first one 

 I saw was about the middle of May, in an unusually battered condition, and from that 

 on until about the end of June they kept increasing in numbers, till they were to be met 

 with everywhere. I requested friends to endeavour to secure for me a number of nearly 

 full-fed caterpillars from the milk weed, so that I might have plenty of material with 

 which to prosecute my investigations. Mr. Balkwill was the first to respond, on the 22nd 

 of July, with a newly transformed chrysalid and several large caterpillars, which were 

 followed by more from the janitor of the Y.M.C.A. Then I made a trip on the street 

 car to a common in the vicinity of his residence, where Asclepias cornuti was growing in 

 profusion, and I secured yet more, so that before the first had emerged I was in possession 

 of fourteen pupse, and Mr. Balkwill added four more to the stock subsequently, and they 

 were all required. 



The great advantage in procuring this particular species for such an investigation is 

 not so much on account of its numbers in an abundant year, or the ease with which it 

 can be fed up, bub in the character of its crysalid, which is a pale translucent green, 

 whilst the butterfly is a bright brown with black veins and white spots. These colors 

 when the pupa is approaching its crisis show through the thin transparent pupa-case, 

 which gisres one an opportunity of clearly observing the progress it is making towards 

 maturity, when it can be arrested at any stage desired ; or, with a little practice, one 

 can tell within a few minutes of the time when it will burst its bonds, and so obtain 

 warning to be on hand to witness its disclosure and development, and then secure it in 

 the proper condition, for the purpose intended. 



I was surprised at the amount of mortality there was amongst the caterpillars after 

 suspension ; although I had been prepared to expect something of the sort from reading 

 the chapter on " The critical periods of it's life" in Dr. Scudder's book, " The Life of a 

 Butterfly." But there is no intimation given therein of the disease that afflicted my 

 stock ; which manifested itself by the caterpillar becoming flaccid, the skin opening and 

 fluid escaping and forming long silky threads. If one of them hung its head straight 

 down I knew it was doomed, and the other symptoms soon followed. It extended to 

 some of the chrysalids. There were no indications of parasitism in my lot. The time 

 from the formation of the pupa to the emerging of the imago was ten to fourteen 

 days. In no instance did any that I saw emerge drop from the pupa-case to cause it to 

 expand its wings suddenly. They came out of their case apparently with great caution 

 and deliberation ; and it took them from ten to fifteen minutes to fully expand their 

 wings. The temperature of the weather through nearly all the period of their emergence 

 was on the cool side, especially the nights, which would tend in some measure to restrain 

 their energies. 



