11 



Norfolk, Berkshire, and Northamptonshire. Perhaps the cause of it may be 

 explained thus : — Small birds, particularly the Titmice, devour the cater- 

 pillars soon after they are hatched, as well as in the following spring, when 

 they are dispersed upon the shoots. So eager are the birds, that they break 

 into their nests late in the autumn, to obtain them. — Kollar. 



Genus III. PIERIS. 



Schrank. 



Pieris, one of the daughters of Pierus, fabled to have been metamorphosed 

 into magpies, for challenging the Muses to sing better than themselves. — 

 Ovid. 



Antennae long and slender ; wings white ; fore-wings rather pointed and 

 tipped with black, in the female always with a black spot near the anal angle ; 

 chrysalis angulated. 



This is one of the largest genera of Butterflies, and its members are dis- 

 tributed over the whole world. As defined by Kirby, it numbers nearly 200 

 species, of which eight are recorded as occurring in Europe. 



We have four British species, all of which, Napi perhaps excepted, 

 appear to be colonists, as are probably also the two species of Colias. Two 

 of them, Brassica and Itapa, as likely as not, were introduced into England 

 amongst the pot herbs of the Romans. The three species — Brassica, Rapa, 

 and Napi — are very prone to variation, and the late Mr. Stephens elevated 

 the different broods to the rank of species. The summer broods are much 

 darker in colour than the spring, and in very hot weather Rapa gets a yellow- 

 ish tinge ; of late years it has acclimatized itself in Canada. Rapes is the 

 first butterfly in the year to emerge from the chrysalis state, doing so, but 

 very rarely, as early as February ; and the caterpillars have been found feed- 

 as late as Christmas. The two species, Brassica and Rapa, are most fre- 

 quently found in gardens ; Napi more often in woods and lanes, and Dapli- 

 dice on the sea coast. 



PIERIS BRASSICiE. 

 Large Cabbage White. 



Brassica, Linn. Bras'sicae, from the generic name of its principal food- 

 plant, Brassica oleracea (cabbage.) 



This is a very common butterfly in this country, occurring as far north as 

 the island of Hoy, one of the Orkneys ; and its caterpillar causes much dam- 

 age in gardens, especially in and near towns, in dry seasons, which are 

 favourable to their production. 



