1602 THE BUTTERFLIES OF NEW ENGLAND. 



EXCURSUS LXIV.— POSTURES AT REST AND ASLEEP. 



BatliPil in the summer moon's white iifrht 

 Lady Butterfly folds lier wings and sleeps; 

 A grass blade her couch, which slowly keeps 



Swinging and swinging the livelong night. 



• J. M. S. 



Butterflies, as a general rule, are very dainty about alighting after 

 flight, appearing to regard the position they shall take with some concern, 

 hesitating more or less about the place they choose ; sometimes they hover 

 about a spot or approach and leave it many times before pitching ; at 

 others two or three quivers of the wing are all that indicate their dainti- 

 ness. Moths, on the contrary, usually come plump to a stop and settle, 

 much as if they had been thrown at the spot ; while among the butterflies, 

 those that in this respect resemble the moths the most closely are the low- 

 est family, the skippers, and some Nymphalidae which are protected by 

 tlieir colors when alight. 



Alighted only for a brief rest, or to sun themselves, or to suck the juices 

 of some flower, butterflies usually keep the wings more or less spread wide 

 open ; though in feeding, especially if it be in companies, or at rest for a 

 longer time, or, as it were, for observation, the wings are usually closed 

 tightly back to back ; among the Pamphilidi, however, there is a very 

 prevalent custom which oddly combines these two, the hind wings being 

 held horizontal, the fore wings perpendicular or a little oblique ; this gives 

 them a curiously disjointed look, the pin-pose of which is not easy to see ; 

 perhaps a comparative study of the attitudes in males and females, or in 

 those species in which the males have and those where they have not a dis- 

 cal stigma, mav lead to some result. 



The need of feeding with erect wings is plain enough in certain 

 instances, as where crowds mingle along the edge of a muddy rut in the 

 road ; and that the same posture is almost invariably assumed at complete 

 rest, as for the night,* is also easily explained, since that presents the least 

 exposed surface, and one which far more than the upper side of the wings, 

 sometimes very completely, resembles in tint and often in texture or mark- 

 ings, the background chosen for rest. 



No creatures seem to be more sensitive than butterflies to warmtii and 

 simshine. We have alluded in a previous excursus (p. 419) to the diurnal 

 movements of even hibernating butterflies ; and one is amused at watching 

 with what precision a Melitaeid for example, or a Polygonia, sidles around 

 on alighting, to expose the broadest possible surface to the sim. Startle 

 one of the latter, but not sufficiently to make it leave the spot, and with 

 what a snap the wings close, and in place of the burning colors which seem 



•Some Hesperidi which rest by day with moths, and very likely all of them do; we 

 outspread wings sleep with roofed wings like know httle of their sleeping attitudes. 



