80 THE REPORT OF THE No. 19 



Those swarms of Archippus that were seen wintering in Florida, probably reached that 

 locality from somewhere in the north, about the end of November. They broke up in February 

 and dispersed. Then, as is naturally to be expected, the sexual desires which had for so long 

 lain dormant were aroused, and they prepared to carry out the purpose of their existence, 

 namely, the multiplication of their kind. With that end in view they must first find Asdepias the 

 food-plant of their progeny ; reported to be always scarce in Florida, and .in February probably 

 no fresh plants of it to be seen there. Where then are they to obtain it? ^Certainly not by 

 going northward at that time of the year, but by going still further south. 



Prof. Riley as early as 1878 made observations upon southerly spring movements, but 

 being confused with the hibernating theory he failed to realize their full significance. From an 

 article in the "Scientific American" for April 6, 1878, a part of which he produced in the 

 "American Entomologist," Volume III., Page 102, I copy the following that bears 

 on the subject. After giving his view of their manner of spreading northward in the summer, 

 and their flocking to the south in autumn, he says: 



"We can thus understand how there are two, three or more broods in southerly regions, but 

 only one toward British America. The exceptional flights noticed in the spring, and which, so 

 far as recorded, take place quite early and in the same soCitherly direction, find a similar 

 explanation. They may be looked upon as continuations of the autumn flights. Hibernating in 

 the temperate belt, the butterflies are awakened and aroused upon the advent of spring, to find 

 the milk- weeds not yet started, and they instinctively pass to more southern regions, where 

 spring is more advanced. " 



Eliminating from that statement the hibernating idea, it is otherwise quite in accordance 

 with what we know of the habits of the butterfly. Whilst the region of which Dr. Riley was 

 speaking being Texas, Indian Territory and Kansas, where the autumn flocks would be gathered 

 from a dift'erent part of the c ntinent than those came from which were seen in Florida, their 

 movements would be influenced by the character of that region, yet their natural disposition 

 would remain the same, which is to move on and extend the species where ever it can find suit- 

 able conditions. Now the whole literature of the species testifies to its being a wanderer. 

 Yet we know by its conduct in the north that it does not wander aimlesly. It seems to have a 

 purpose and " a method in its madness " in that respect which looks wonderfully intelligent. 



That habit being constitutional to the species, it will be found in some measure to in- 

 fluence every individual of it and control its movements to the utmost limits of its nouthern 

 habitat on this continent, therefore, we are not warranted in restricting its northerly migratory 

 movements in the spring to those individuals found in the more northern portions of its southern 

 home. For those northern bred specimens that wintered there, when they have been aroused 

 t) activity by the approach of their breeding season, will move southward for we know not how 

 far, depositing eggs as they go before they are exhausted, whilst at the same time, tho^e born 

 in extreme limits of its southern breeding grounds, impelled by that intense desii e to travel and 

 spread its kind will be moving northward. Thus migrations in opposite directions will be going 

 on together ; and it may yet be discovered, that the majestic sweep of that annual movement is 

 far more extensive, regular and continuous than has ever been suspected. 



On such considerations as these, in the absence of actual observations, we have to de- 

 pend in forming our conclusions as to when, and from whence, the first arrivals in the north 

 have their origin. Those that reach West Virginia about the end of March, would appear 

 necessarily to come from somewhere much further south than Florida ; whilst those that reacn 

 Ontario about the end of May, might be born there or thereabout. But so much depends upon 

 the character of the seasons, and the directness or otherwise of the flight of the butterflies, 

 that all positive conclusions must be withheld. The climate of Florida is not always favorable 

 as a winter residence for the butterfly. Cold waves from the north descend upon it at times. 



