ARICIA MEDON. 275 



•did so, would be in way of the body) so as to pass the inner margin 

 beneath the abdomen, as it does when sunning itself with widely- 

 opened wings. In confinement it will feed greedly on moistened 

 sugar, and readily returns again and again to the feast even when 

 one would consider that it must be satiated. When walking the 

 legs are moved alternately, and it can walk very rapidly. When 

 ilying, its flight is difficult to follow, and it flies only in the 

 bright sunshine. It prefers thistles and knapweed when seeking food. 

 It is very pugnacious, and may often be seen battling with Polyommatus 

 icarus &nd Epineplielejanira. It rests at about 7.30 p.m. In Durham, 

 it rests on plantain heads and grass stems, with P. icarus, and, less 

 •commonly, on the flowers of geraniums, but in Scotland, I have found 

 it resting on plaintain heads, the flowers and stems of Campanula 

 r/lomerata, and upon the bare ground. When resting with P. icarus it 

 can be easily distinguished by the superior length of its wings. Any- 

 one wishing to know the use of the eye-spots on the underside of the 

 wings, should see a few imagines at rest on the heads of Plantayo 

 lanecolata between 8 p.m. and dusk (Harrison). In sunshine the 

 butterfly is a very active little creature, w r hicb is easily lost sight of 

 when flying rapidly over the meadow, especially w^hen the two sexes 

 are amusing themselves with love-affairs. They then flew rapidly 

 in wide curves over the meadow, and were in a moment lost to my 

 sight, but just as quickly they returned, singly, into my neighbour- 

 hood. When they flew rapidly in the sunshine they seldom settled on 

 a flower; only in the morning and evening did I see them quieter, and 

 feeding on heath and other meadow-flowers (Gillmer, in litt.) Barrett 

 observes that it is " not a very active butterfly," but " flits quietly 

 about warm hillsides and open fields, or the sheltered sides of sand- 

 hills;" he adds that it is "very fond of resting and sleeping on tall 

 grass stems, particularly on the rolled up leaves of the marram grass 

 (Amnwphila arvensis)." Both Tugwell and Duncan remark on its 

 fondness for resting on the flow T ers of the common rush, and Stewart 

 and Buchanan Yv^hite speak of it as specially attached to blue flow 7 ers, 

 the former particularizing the blue scabious (Knautia arvensis), and 

 the latter Lycopsis arvensis, the bugloss. On July 21st, 1899, a 

 specimen was found by Studd in his light trap at Oxton, Devonshire. 



Times of appearance. — There is not the same difficulty in fixing 

 the number of broods in Britain in this species as is experienced in the 

 case of Polyommatus icarus. The line of demarcation between the 

 single and double-brooded areas falls approximately across the centre 

 of England. Wailes observed that if we draw an isothermal line 

 across Europe of 51° the localities to the north of this will be found 

 to produce one brood only, those to the south of it two. He has, how- 

 ever, fallen into the error of placing the average temperature a degree 

 above 50° instead of below, as is shown by the average temperature 

 given bv him for the localities he cites, and instead of an isothermal line 

 of 51° Farh. we should read 49°, in which case his observation becomes, 

 with but few exceptions, remarkably correct. In the South of England 

 the species is regularly double-brooded in all seasons, though it is possible 

 that some larvae of the early summer brood hibernate even in the 

 regularly double-brooded area; this reaches further north than was 

 supposed by Newman, for the species appears twice in the year both in 



