1.6 



The wings, which ordinarily expand from one inch and a half to two inches 

 and a quarter, are white, with a black or triangular blotch at the tip of the 

 fore-wings, and a black spot on the upper edge of the hind-wings. The 

 male has one, the female two black spots on each fore-wing. The blotch at 

 the tip is larger in the female than in the male. The under surface of the 

 hind-wings is yellow. 



Yar. b. is distinguished from the typical variety by the upper surface of the 

 wings being of a cream colour. There is no difference in the black mark- 

 ings. It appears in very hot weather, or early in the spring when bred under 

 glass. 



Tar. c. differs from the preceding in the black blotch at the tip of the 

 wings being paler, and the spots on the fore- wings being very indistinct. 



Yar. d. (Metra, Steph.) differs from the last variety by the spots on the 

 fore-wings being entirely obsolete, and the tips are merely shaded by a few 

 dark points. It generally appears in April. 



Yar. e. has all the wings above immaculate white, with the base black, and 

 the apex of the hind- wings very obscurely clouded. 



Yar. /. is distinguished by having a deep black patch at the base of all 

 the wings. In other respects, like the type. It was bred by myself in 1869. 



Yar. g. (Novanglia, Scudd) is canary yellow. It is extremely rare in this 

 country, but not so in America. 



There are apparently three broods in the course of the year, the first ap- 

 pearing in April or even earlier, and stragglers of the last may be observed 

 till past the middle of October; sometimes their third brood does not appear 

 when a late or dull season has retarded the developement. 



The egg somewhat similar to that of the preceding species, is in shape 

 like a flask, with longitudinal ribs, coming up neatly and evenly to the apex, 

 and has delicate reticulation. It is at first of a pale greenish yellow, and 

 and afterwards becomes more yellow. 



The caterpillar, very different to that of the preceding species, is of a 

 dull- green colour, with a yellow dorsal stripe, and yellow dots on the sides. 

 It differs also from Brassica, which only feeds on the outer leaves, by eating 

 into the very heart of the cabbage, and is often cooked. The caterpillar has 

 been observed late in December. 



The chrysalis is either dusky-drab, rosy pink, or dull-green, and has three 

 narrow greenish -yellow longitudinal stripes. 



Rapce in a similar manner to Brassica, is very subject to the attack of 

 parasites, and the following have been bred from it — Apanteles glorneratus 

 and rubecula, Henteteles fulvipes, Mesochorus aciculaius, Pteromalus puparuw, 

 and Exorista vulgaris^ 



