THE SMALL WHITE. 37 



The spring form of this butterfly, named metra by Stephens, 

 who, together with others, considered it a good species, has 

 the tips of the fore wings only slightly clouded with black ; 

 and the black spots near the centre of the wings are always 

 more or less faint in the male. Sometimes the central spot 

 and also the blackish clouding of the tip are entirely 

 absent. The summer brood, on the other hand, has fairly 

 blackish tips and distinct black spots — one in the male 

 and three in the female, the lower one lying on the inner 

 margin. Occasionally examples of this flight bear a strong 

 resemblance to the Green- veined White, the next species. The 

 wings are sometimes, chiefly in Ireland, of a creamy colour, 

 more especially in the female, or, more rarely, of a yellowish 

 tint. In North America, where this species was accidentally 

 or intentionally introduced some years ago, bright yellow forms 

 are not uncommon in some localities, and the variety is there 

 known as novanglice. 



In certain favourable years a partial third brood has occurred, 

 but such specimens are often small in size. 



The egg (Plate 8) is at first pale greenish, but later on 

 it turns yellowish, and this tint it retains until just before the 

 caterpillar hatches out. 



The caterpillar when full-grown has a brownish head 

 and a green body ; the latter is sprinkled with black and 

 clothed with short blackish hairs emitted from pale warts. 

 There is a yellowish line on the back, and a line formed of 

 yellow spots on the side. It feeds on most plants of the 

 cabbage tribe, and in flower gardens on mignonette and nastur- 

 tiums. It is often attacked by parasites, and especially by the 

 Apanteles, referred to as destructive to caterpillars of the Large 

 White. 



The chrysalis may be of various tints, ranging from pale 

 brown, through grey to greenish ; the markings are black, 

 but these are sometimes only faint. It is to be found in 



