1900 ] ENTOMOLOGICAL SOCIETY. 45 



" So far as one is able to get at the real facts (i. e., apart from the opinions of ob- 

 servers,) one is able to conclude that the movemeDts of Anosia Archippus, in North 

 America, are very similar to those of Pyrameis cardui, (the Thistle butterfly) in 

 Europe." After quoting from various sources, Mr. Tutt adds: " All these irregularities 

 of habit will be certain to strike one who has studied the subject, as being readily par- 

 alleled during a series of years by the immigrants of Colias edusa and Pyrameis cardui, 

 and their progeny in our own country." That is, Britain. 



After quoting a diversity of individual opinions and contentions, he continues, 

 " However little definite information there is about the spring migration of A. archippus, 

 a great number of observations have been recorded of a habit that is certainly unknown 

 in any of our most observed Palaaarctic migrating species. This is the habit of swarming 

 in che autumn." He then gives a large number of instances that have been observed by 

 different persons, of autumnal swarms passing over various parts of the continent ; then 

 continues, " One other observation may be added, ihat of Bowles, who states that he 

 has himself seen the shores of Lake Ontario, near Brighton, strewn with hundreds of 

 their dead bodies, cast up by the waves, and which no doubt had formed part of a 

 swarm, which from weakness or some other cause had perished while flying across the 

 lake." Then Mr. Tutt sums up his conclusions upon the subject thus : 



" From these and similar observations it has been concluded that the swarming of 

 this butterfly in autumn is analogous with that of birds before commencing their [flight 



southward, and that, after swarming, the butterflies return to the subtropical lands 

 whence their grandmothers and great grandmothers set out in spring. It is admitted 

 that the climate is such, in the northern territories to which the species annually spreads, 

 that the butterfly cannot possibly exist in the winter, and Riley, who first propounded 

 the return theory, himself confesses that " under the most favourable conditions a lar^e 

 majority perishes." As we have said, Scudder accepts the theory as fact, and practically 

 writes as if it were proved beyond question of dispute. For ourselves, although we know 

 of no exact analogy among butterflies of a similar swarming habit, yet, in every other 

 respect the similarity between the habits of this species and our own European mi^ratinc 

 species, Pyrameis cardui, Calais edusa, etc., is so great, both as to the continuous- 

 brooded habit, and also as to Dr. Thaxter's observation that the males and females in 

 the autumnal swarms pair, that we are inclined to doubt the conclusion. It has never 

 yet been shown that the journey has been successful. The swarms are sometimes noted 

 as going in a different direction from that assumed by the theory, and much more 

 evidence is necessary before even an approximation to success can be admitted. For our- 

 selves, we doubt M hether the return journey has ever been successfully made, and we 

 consider that there is altogether insufficient direct evidence to warrant the assertion that 

 the autumnal swarms of Anosia Archippus migrate from the more northern parts of its 

 summer range in America, to the south, in order to winter there. Some of the quota- 

 tions which we have just reviewed, and others mentioned by Riley, show distinctly that 

 he swarms do sometimes fly more or less from north to south, or from north-east to 



