1 8 THE MOTHS OF THE BRITISH ISLES. 



central area of the wings is olive green, usually dark, and 

 generally edged with whitish. This band is sometimes entire 

 (typical), but more frequently it is broken about the middle. 

 The outer third of these wings is more or less greenish or 

 mottled with green, and a mark near the tip is whitish. 



Variation is chiefly connected with the modifications that 

 occur in the upper or lower, sometimes both, portions of the 

 central band ; the lower seems to be the first to disappear, then 

 the upper passes through various stages of reduction until it 

 becomes simply a spot or dot about the centre of the wing. 

 Specimens are occasionally found or reared, in which eveiy 

 trace of the band has departed from one or iDoth fore wings. 

 The greenish outer border of the wings is inwardly margined with 

 darker, well defined and band-like in some examples, but less 

 clearly marked, or even absent, in others. Near the base 

 of the fore wings are often two dusky greenish cross lines. The 

 hind wings, generally pretty much of the same ground colour as 

 the fore wings, have a dusky band-like shade of variable 

 width on the outer third ; sometimes these wings are entirely 

 dusky, approaching blackish. Very rarely specimens are bred 

 in which there is no trace of green colour. Such an example 

 was reared by Mr. Frohawk in April, 1882, from a caterpillar 

 he found in Surrey. In this aberration all the markings 

 (normally green) are light burnt-sienna red, the usual whitish 

 blotch at the tip of the fore wings is pink ; ground colour also 

 pink, slightly tinged with grey in places. So variable is this 

 moth in colour and markings, that in some collections at least 

 one cabinet drawer is given to it so that the range of aberration 

 may be adequately shown. Already about eighteen colour 

 modifications have been named, and at least eight band 

 variations have also received names. 



The egg is similar in general appearance to that of the next 

 species (see Plate 4). Dr. Chapman states that it is more densely 

 covered with an indiarubber-like gum, and this may cause it to 



