THE PAINTED LADY. 79 



bottom of which is the micropyle. The fine cross-ribs form 

 slight bosses at their junction with the upright ribs. The eggs 

 are laid on the leaves of the thistle, but usually only one on a leaf. 



The caterpillar is rather stout for its length. It has a 

 dark greyish head, which is covered with short bristles. The 

 ground colour of the body varies from greyish-green and 

 ochreous-grey to blackish, and in the darker colour is generally 

 freckled with paler, sometimes yellowish. There is a black line 

 along the back, often edged with yellowish, and sometimes 

 much broken up ; the lines on the sides are yellowish, but 

 not always distinct ; the line below the yellow-ringed black 

 spiracles, however, is generally broad and yellowish in colour. 

 Although thistles {Car dims) appear to be the plants most 

 frequently eaten by these caterpillars, they have sometimes 

 been found feeding upon mallow (Malva), burdock {Arctium), 

 viper's bugloss {Echium), and even nettle {Urtica). They 

 commence life by fixing up the edges of a leaf so as to form 

 a sort of pocket in which to conceal themselves, but as they eat 

 away the fleshy part of the leaf their retreat is easily detected. 

 The hiding-place, or dining-room, of a full-grown caterpillar'is 

 shown on the plate ; changs to the chrysalis is often effected in 

 a somewhat similar structure. 



The chrysalis is grey, ochreous-grey, or greenish ; shaded 

 or striped with brownish. The raised points are burnished, and 

 according to the way light falls on them appear golden or 

 silvery. This metallic effect is also seen on other parts of the 

 chrysalis, but chiefly on the back. 



This butterfly is a notorious migrant. Its proper home is 

 probably in Northern Africa, and there it, at times, becomes so 

 exceedingly numerous that emigration is possibly a necessity 

 in the interests of future generations of the species. Whatever 

 the cause of their leaving may be, there is no doubt about the 

 fact that the butterflies do quit the land of their birth in great 

 swarms. Almost any part of the world may become the 



