WfcRIS. 147 



Asia, many closely-allied races are met with, some of which are 

 probably simply local forms of this Butterfly, while others are 

 to be ranked as distinct species. Rather more than thirty 

 years ago, this Butterfly was introduced into North America 

 (where, however, several closely-allied species are truly indi- 

 genous), and has since spread over the country, and become 

 very destructive. It has also developed a yellow variety 

 (P. novanglice, Scudder), which is very rarely observed in any 

 other part of its range. 



The Small White Butterfly measures from ij to nearly 2^ 

 inches across the wings, which are coloured nearly as in P. 

 brassica. The wings are rather more yellowish than in the last- 



Upper side of female. 



named species, the fore-wings having an ash-coloured blotch 

 at the tip, much smaller and paler than in P. brassiccz. The 

 male has a black spot on the disc (often wanting), and the 

 female has two ; the patch on the inner-margin is less distinct. 

 On the hind-wings there is a black spot on the costa towards 

 the tip. On the under side, the fore-wings have two black 

 spots, the tip is yellow, and the base dusted with blackish. 

 The hind-wings are rather bright yellow, dusted with black, 

 and there is a narrow orange streak at the base of the costa. 



The larva is pale green, with yellow dots on the sides. It 

 feeds on cabbage, mignonette, &c. ; and there is probably a 



L 2 



