GREEN-VEINED WHITE. 87 



to tip. The intensity of the dark markings, on both 

 the upper and under sides, is also subject to much 

 variation. 



But, under all these circumstances, the presence of 

 dark cloudy veins on the under side appearing, but 

 less distinctly, on the upper side will at once distin- 

 guish it from the last species, the only one with which 

 it can possibly be confounded. 



The male has only one round spot on ihe front wings ; 

 the female being marked as in the plate. 



Both in woods and cultivated grounds we meet with 

 this butterfly commonly enough, most abundantly in 

 May and July, though it may be found from April to 

 August. 



The caterpillar feeds on the same tribe of plants as 

 the two last, but is supposed to be especially attached 

 to the Eape (Brassica Napus\ whence its specific name. 

 Its colour is green, with yellow spots round each spi- 

 racle, which is itself tinged with red. 



Two varieties of this were formerly ranked as distinct 

 species, under the name of P. Sabellicce and P. Napww. 



