146 THE BUTTERFLIES OF NEW ENGLAND. 



will settle on the ground a little distance off by a crevice in the rock-piles, 

 and as you cautiously approach you will see it edge its way afoot in its 

 spasmodic fashion to the brink of the crevice and settle itself ; then if you 

 come nearer it will start as if to fly away, but close its wings instead and 

 fairly drop down the crevice, where you may see but not reach it ; to repeat 

 the process and get still farther down, if again alarmed by the removal of 

 the upper rocks. In this way I have more than once followed one for a 

 couple of feet doAvnward in a pile of small, jagged rocks in one of the rock 

 rivulets. 



It rests on the ground, or on the leeward side of rocks, as I have often 

 found it when searching on a cloudy day when it had not been on 

 the wing. As soon as one alights it tumbles upon one side with a sudden 

 fall, but not quite to the surface, exposing the under side of the wings 

 with their marbled markings next the gray rock, mottled with brown and 

 yellow lichens, so that an ordinary passer by would look at them without ob- 

 serving their presence ; it is an obvious case of protective resemblance. The 

 surface is generally exposed so as to receive the fullest rays of the sun, or 

 else the creature falls so as to let the wind sweep over it, its base to wind- 

 ward. In either case, unless the wind be very severe, the fore wings 

 are not closely tucked between the hind pair, but advanced so that 

 the costal edge of the hind Avings reaches the lowest, or the next to the low- 

 est, inferior subcostal nervule, according to the degree of quiet assumed ; 

 but if at rest for the night or the wind be sweeping fiercely, the costal 

 edges of all wings are brought together. The antennae lie parallel to the 

 body-axis, or slightly raised, but, owing to the basal curve, in a plane 

 slightly above it, droop at the tip and divaricate about 100°. In walking, 

 it moves by a series of spasmodic starts, trailing the tip of the abdomen on 

 the ground, while the axis of the trunk is raised about 30° above the surface 

 of rest. 



Dr. Meyer Diir describes the species of the European Alps as generally 

 flying in little companies about rocky places, fluttering in a wavering man- 

 ner around the Saxifragae and Ericaceae, but generally alighting, with wings 

 erect, on blocks of rock and worn stones, where they are not easily caught. 



Experiments. 01)serA'ing that the butterflies appear to keep aAvay from 

 the immediate vicinity of the great ravines which penetrate dee}) into the 

 mountain mass, as if they feared they would be swept down to lower levels 

 than they liked, I thought I would see what eflfect a forcible and rapid 

 transfer to lower levels would have upon vigorous butterflies. Accord- 

 ingly one fine July day, I took three well-conditioned females (one of 

 them caught just before imprisonment) down the mountain on the railway 

 train, in a muslin cage over a growing sedge, where I could readily watch 

 them. They remained quiet at first with wings tightly closed, but before 

 Ave had made more than half the descent to the limit of trees they were visibly 



