64 



PSYCHE. 



[June iSSS. 



extreme southern portions of New Eng- 

 land and the neighljoring districts, we 

 have not infrequent appearances of 

 hibernating butterflies early in JMay. 

 But neither hibernators nor their pro- 

 geny, in the preparator}- stages — the 

 only absolutely certain proof of an early 

 brood, — are with possibly rare excep- 

 tions to be found in the northern half 

 or i^iore of New England either in 

 May or early in June. The first occur- 

 rence of the insect there in any form is 

 much later in tlie season, generally by 

 the middle of June, occasionally bv the 

 very first, sometimes not until the ver}- 

 end of this month, when fine fresh but- 

 terflies make their appearance, at about 

 the same time as, or a trifle later than, 

 the advent a little further south of the 

 first fresh brood of butterflies from eggs 

 of the same season, — thus giving all the 

 appearance throughout New England 

 of an identical swarm of butterflies, 

 varying in time from those found next 

 the southern borders of New England 

 only so much as would be expected 

 from latitude. 



This brood is in my opinion to be 

 accounted for onl\- on the supjDosition 

 that they are colonists fro?n the south 

 which have flown to more northern 

 ilistricts from that impulse to wander 

 which is one of the j^^ychologi- 

 cal characteristics of this butterfl}-. 

 This hypothesis is further su2^ported b}- 

 the essentially tropical nature of the 

 butterfly, which w^ould prevent its es- 

 tal^lishing itself as a permanent resident 

 ratlier than as an annual visitor of 



nortliern districts; by its well-known 

 vast po\^'er of flight ; as well as by its 

 comparative history in the south. 

 These butterflies begin in New Eng- 

 land to lay their eggs usually in the 

 first week in Julv, but occasionally as 

 early as the middle of June. Dr. Har- 

 ris records some caterpillars found on 

 the 3Sth of June which had reached the 

 length of an inch on the 5th of July, 

 and I have foimd them in Shirle}', 

 Mass., of the length of six millimetres, 

 therefore probably in the second stage, 

 on the 22d of June. These were unu- 

 sually early caterpillars of the brood 

 which had flown from the sout') and 

 which sometimes makes its advent 

 early in June. Both Mr. F. H. Sprague 

 and myself have found them about 

 Boston as early as the 2d of this 

 month in good condition, and single 

 additional specimens were found in the 

 same year by Mr. Sprague on the 9th 

 and i5thofJime. They never, how- 

 ever, become at all abundant before the 

 first week in July, when the eggs are 

 ordinarily laid. The eggs continue to 

 be laid throughout this entire month 

 without any interruption. 



As regards the later history of this 

 butterfly in the north, we are still 

 somewhat in doubt. Mr. Edwards 

 urges with great pertinacity that the 

 behavior of the butterfly in the north is 

 altogether parallel to its behavior in the 

 south, but this would hardly seem as 

 yet to be settled ; at any rate the ap- 

 pearance of the latest fresh butterflies 

 of the season may easily be accounted 



