176 BIUTISH BUTTEBFLIES 



about ; but when the dense shadow of a passing cloud creeps over 

 the ground they rapidly disappear from view, having settled down 

 to rest on leaves and stems. Tlien, as soon as the shadow passes 

 away, the air is again enlivened with their si)orts and tlittings. 



The Wood Argus is a marked exception to this rule. It 

 delights in the cool shade of the narrow paths of woods, where it 

 slowly ilies up and down the lonely footpath, taking but little heed 

 of strangers that intrude on its haunts, and seldom venturing into 

 the full blaze of the sun unless pursued. Even on dull days it 

 continues its solitary flight, and may even be seen on the wing 

 while a soft rain is bathing the dripping foliage. 



The upper surface of this prettj' butterfly is shown on Plate V, 

 fig. 5, and the under side in the accompanying woodcut. Both 

 sides are prettily marked with various shades of brown and buff, 



and adorned with white-centred 

 dark eyesj)ots which have earned 

 for it the name of Argus. 



It first appears on the wing in 

 April, and may be seen from this 

 month continuonslj' to the end of 

 August. 



The food plants probably consist 



of manj' species of grasses, the 



Fig. 78. — The Wood AbctUS— cock's-foot {Dactylis glomerata) 



Under Side. ^nd couch grass {Agropyron rejyens) 



being among the number, and the 



eggs are laid on or in the neighbourhood of these during the summer 



months. 



The caterpillar of this species is of a dull greenish or brownish 

 colour, and it has two whitish stripes (sometimes three) down the 

 middle of the back, and similar stripes along each side. It 

 hybernates during the winter, and is full grown in IMarch, when it 

 changes to a dull green or brownish chrysalis, which is streaked 

 with black, and has a few white dots on the back. 



It has been stated that the butterfly is on the wing from April 

 to August, and, according to some authorities, there are no less 

 than three broods during this time, following each other in rapid 

 succession. It is common throughout England and Ireland, and is 

 known in parts of Scotland. 



