64 . BRITISH BUTTERFLIES. 



owe their difference in size simply to their being old 

 and young individuals of the same name ; forgetting 

 or, rather, never having heard that butterflies never 

 grow in the slightest degree after once getting their 

 winged form ; only as caterpillars do they grow. 



The male is distinguished from the female by having 

 only one round Hack spot, or sometimes none, on each 

 upper wing, whilst the female is spotted as in the 

 engraving. The under side of the hind wings is dull 

 yellow^ lightly powdered with black scales. 



The butterfly is seen during nearly the whole of the 

 summer, and is found almost everywhere. 



THE GEEEN-YEINED WHITE BUTTEKFLY. 

 (Pieris Napi.) (Plate IV. fig. 4.) 



Is so called from the greenish tint that often borders 

 the veins or nervures on the under side of the hind 

 wing ; but the name is not always an appropriate one, 

 for a large proportion of the specimens met with have 

 the veinings grey, and not at all green ; but the fact is, 

 that the ground colour varies greatly, from creamy 

 white to full buff, or bright clear yellow ; in the latter 

 case it is, that the minute black scales which border the 

 course of the nervures, covering over the yellow, pro- 

 duce a grey-green effect on the eye. 



The size also is very variable. I have a specimen 

 that expands two inches and two lines across, from tip 

 to tip, and have seen another not larger than a small 

 Copper butterfly little more than one inch from tip 

 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 



