THE GREEN-VEINED WHITE 39 



may closely resemble one of the first brood. As a rule, how- 

 ever, the seasonal differences referred to are fairly constant. 

 By rearing this species from the egg it has been ascertained 

 that part (sometimes the smaller) of a brood from eggs laid in 

 June attains the butterfly stage the same year, and the other 

 part remains in the chrysalis until the following spring, the 

 butterflies in each set being of the form proper to the time of 

 emergence. 



The strongly-marked specimens (Plate 14) are from Ireland, 

 and are of the first or spring brood. The seasonal variation 

 in this species is not so well defined in Ireland as in England. 



A form of variation in the female, and most frequent perhaps 

 in Irish specimens, is a tendency of the spots on the upper side 

 of the fore wings to spread and run together, and so form an 

 interrupted band. 



Specimens with a distinct creamy tint on the wings are some- 

 times met with, but such varieties, as well as yellow ones (var. 

 /lava, Kane), are probably more often obtained in Ireland and 

 Scotland than in England. Occasionally male specimens of the 

 second brood have two black spots on the disc of the wing. 

 Some forms of this butterfly have been named, and these will 

 now be referred to. 



SabelliccB (Petiver), Stephens, has been considered as a species 

 distinct from P. napi, L. Stephens ("Brit. Entom. Haust.," I. 

 PL iii., Figs. 3, 4) figured a male and a female as sabellicce, 

 which he states differs from napi in having shorter and more 

 rounded yellowish-white wings. No locality or date is given 

 in the text (p. 21) for the specimens figured ; but referring to 

 another example which he took at Highgate on June 4, he says 

 that it agrees with his Fig. 2. Probably, however, it was his 

 second figure that he intended, the Fig. 4 of the plate, which is a 

 female. This is rather more heavily marked with dusky scales 

 than is usual in specimens of the first brood, at least in England, 

 although it agrees in this respect with some Irish June examples. 



