1086 THE BUTTERFLIES OF NEW ENGLAND. 



Quite similar swarms of this species have often been observed and it will 

 be sufficient herein to refer the reader to the tables of AVerneburg and the 

 more detailed accounts by Keferstein. 



The only instances of butterfly migrations belonging to other groups 

 than those I have mentioned are two collected bv Werneburer ; one is a 

 Lycaenid, the other a Papilionid. The first is presumed to be Chrysopha- 

 nus hippothoe of Europe, which on June 1, 1860, in the valley of Vigor in 

 southern France, flew in a northerly direction in immense crowds in more 

 or less numerous bands from 10 A. M. till evening ; all were males. The 

 other is where more than twenty individuals of Menelaides hector were 

 seen together two hundred miles from land between the isliinds of St. Paul 

 and Ceylon. 



In studying the movements of Anosia plexippus, which have been fully 

 detailed under that species, I have been led to the conclusion that this but- 

 terfly makes periodic movements as regularly as the birds. The regularly 

 recurring movements of other butterflies leads me to think that were 

 observations made with more care and continuity, similar conclusions would 

 be reached in other instances. I commend especially to those who arc 

 sceptical on this point, the following statement : — 



Dr. Karl Fritsch, a Vienna naturalist who has given special attention to 

 field observations upon the seasons of insects, is inclined to believe that in 

 1879, when Vanessa carduiwas extraordinarily abundant all over Europe, 

 its movements coidd be compared to those of summer visitors among the 

 birds, moving north in the spring and south in the autumn. Dr. Katter 

 had summed up the earlier observations of this year in tlie statement that 

 the butterflies probably crossed the Mediterranean from northern Africa, 

 and from Sicily and Spain spread over Europe. Dr. Fritsch therefore 

 stationed himself in his garden, which had a fair outlook, for several hours 

 every day, near noon, from early in July to near the end of October, and, 

 by observing and noting the dii-ection taken in flight by every single speci- 

 men, discovered that there was no prevailing direction imtil August 26, 

 when, and until October 20, with few exceptions, the prevailing move- 

 ment was towards the west-south-west and south, or diametrically oppo- 

 site to the prevailing movements of the swarms in June. 



Here, then, the return movement of butterflies, the apparent absence of 

 which so perplexed Mr. Belt, was by careful and minute observations 

 made clear. It is in no way improbable that it is a regular and permanent 

 feature of all migrations among butterflies. In this instance the collec- 

 tive movement was in the spring, the individual movement in the autumn ; 

 in Anosia plexippus the case is exactly reversed. Why may there not in 

 many cases be individual movement at both seasons, which has been over- 

 looked for want of just such careful observations? 



