342 BRITISH BUTTERFLIES. 



path for a short distance, easily keeping out of reach, until attracted by 

 a plant of thyme, upon which it settled suddenly, and commenced at 

 once sucking greedily at the nectar, its head buried deeply among the 

 flowers. Between Airolo and Piotta, on the afternoons of August 3rd 

 and 4th, the species new very swiftly, settling rarely, up and down the 

 flower-banks sloping down to a wide alder-carr. At the same place, on 

 the afternoon of August 7th, after two most stormy days, the sun came 

 out hot for about an hour; at about 4-30 p.m. two avion were observed 

 at rest in the sun, but with their wings upright over their backs, and 

 both on unexpanded flower-heads of scabious; they were, therefore^ 

 not feeding, but simply at rest. One stood on the top of the capitulum, 

 its antenna? projecting in front, and viewed from the side, appeared to 

 be very conspicuous ; the other stood, head downw T ards, on the side of 

 the flower, and was much less conspicuous, yet the dark leaden under- 

 side made it easily seen once the eye was in line with the insect. In 

 spite of their seeming stillness, they were easily disturbed, and in the 

 sun, flew off quite rapidly. 



Our experience of the species, based on careful observation in 

 Ticino, in 1907, is that it is exceedingly restless in the hot sun, flying 

 swiftly, although with what appears to be a heavy, zigzag flight, at some 

 distance above the herbage, which makes it somewhat difficult to follow 

 on the steep flowering alpine banks it usually haunts in the Reuss and 

 Ticino valleys ; when at rest on flowers, however, it is easily approached 

 and equally easily captured, but if startled, its dull, heavy blue-black 

 colour is seen only for a moment, and one rarely gets a second chance 

 at the same individual. At Chavoire the species was observed to fly 

 rapidly and strongly in the hot morning sun, not remaining long at 

 each rest, but at other times it appears to be less restless. Matthew observes 

 that the butterflies are swift and strong on the wing settling suddenly 

 on a sprig of heather or other flower, whilst Wheeler, in the same way,, 

 speaks of their suddenly appearing on the flowers of the wdld thyme 

 in the Rhone Valley and on the Simplon Pass, " coming apparently 

 from nowhere." Marsden says that they love light, warm weather, and 

 appear always to be still in dark, cloudy weather, only depositing their 

 eggs when the sun is warm and bright ; we, however, in the deplorably 

 wet summer of 1910, when passing a day on Mt. Vuache in company 

 with Prof. Blachier, remarked that avion appears to fly more readily 

 in dull weather than any other of the " blues" observed, the species 

 we saw on that occasion consisting of Cyanivis sentiargus, Agriades 

 coridon, Polyonuiiatus hylas, V. icarus, Cupido minimus, C. osiris (sebviis), 

 Aricia medon and Everes alcetas. Rapidity of flight does not ahvays,. 

 however, characterise this species in the favoured haunts in which it 

 apparently feels at home. Goss observes that on the Cotswolds "there 

 was no probability of mistaking it for any other species, its larger size, 

 dark iron blue colour, somewhat heavy wobbling flight, sufficiently 

 distinguishing it ; also that it naturally flies more in the manner of 

 K. tithonus or A. hyperanthm than any of its congeners, but when 

 pursued or frightened, is sufficiently strong on the wing. 



Bond says that it is an easy insect to take, flying very low, con- 

 spicuous, settling occasionally on wild thyme in Barnwell Wold. 

 Marshall again says : " It is usually an easy insect to take, and I think 

 Dr. Bree right in describing the usual flight as not unlike that of 

 Coenonympha pamphilas, but I have also seen it careering wildly about 



