1901 



ENTOMOLOGICAL SOCIETY. 



each succeeding winter these regions where it is produced in the greatest abundance have to be 

 replenished in the spring by individuals coming from the south. (L'^sing these geographical 

 terms in an undefined manner). Its noticeable habit of congregating in immense swarms in the 

 north at the end of summer, combined with their utter disregard for each other sexually, whilst 

 closely associated with each other individually for so long a time, is without a parallel in any 

 other known species and therefore has a special significance of its own. Then the fact that 

 these swarms move off together on the approach of winter, as if by mutual understanding, in a 

 southerly direction, combined with the fact that similar swarms have been observed on more 

 than one occasion wintering in the south, where such multitudes could not have been bred on 

 account of the scarcity of their food plant there, clearly indicates that they had come from the 

 north where they are bred in such profusion. When I wrote my paper for the 31st annual 

 Report of the Entomological Society of Ontario, 1900, although quite convinced that Anosia 

 Aichippus was not a hibernating butterfly, yet I could not produce the evidence mecessary to 

 sustain and justify my belief, so I sent a copy of that report to Dr. Thaxter with a note calling 

 his attention to it, that he might have an opportunity of correcting any eiToneous conclusions I 

 had arrived at, if he thought necessary. In return I received a most genial acknowledgement 

 from the doctor, from which I have the pleasure of copying the following statement which is 

 connected with the subject in hand : 



" A.bout those Archippus butterflies I have a memorandum on the sketch which I made at 

 A ppalachicola [which was published in the Canadian Etdomologist, vol. xii. (1880) page 38], 

 Fig. 46 to the effect that it was drawn from nature January 3rd, 1873. If I remember rightly 

 the butterflies did not begin to scatter till February and then many were seen in coitu." 



That appears to be concludve and makes it certain that those flocks of Archippus butterflies 



seen by Dr. Thaxter in Floiida(Fig. 46), were not 

 there in search of a place to hibernate, but with 

 the intention of passing the time in an active state 

 until their season for breedirg had arrived. The 

 chain of evidence now seems to be complete, al- 

 though every link in that chain has not yet been 

 forged ; that those immense swarms that come 

 together in the north where they were produced in 

 such profusion, take their departure in flocks from 

 the north for the very purpose of going south to 

 winter there. Not always in a direct line but 

 always tending in that direction, their movements 

 are influenced by the nature of the route and the 

 Yig. 46. character of the weather. Not rushing impetuously 



• inward tu their destination as some butterflies are reported as doing, "Entomologist's Record," 

 vol. xiii., page 98, but as becoming their regal character, deliberate and dignified in all their 

 movements ; enjoying their journey and the novelties of the way ; having none of the distrac- 

 tions of family affairs to disturb their equanimity, being quite conscious that the serious busi- 

 ness of their life is well off in the future and that in good time they will reach a suitable locality 

 where they may spend the winter in comfort and safety. 



Having thus obtained a satisfactory explanation of their autumnal gatherings in the north, 

 as part of their constitutional habit of wintering in the south, one may regard that portion of 

 Archippus life history as conclusively settled, and turn our attention to its spring movements, 

 and enquire, when and from whence do the northerly migrations originate? In the absence of 

 observed data we will have to be guided in the formation of our opinions on the subject, by 

 the well known habits of the butterfly, and the climatic conditions of the localities it frequents. 



