20 



Fig. 12. 

 Tlie expanded wings, Fig. 12, male, measnre about two inches, 

 are white above with the base dusky. Both sexes liave the apex 

 black and a black spot a little beyond the middle, and the female, 

 Fig. 13, has another spot below this. The under side of the fore 

 wings is white, yellowish toward the apex, and with two black spots 

 in both sexes corresponding to those on the upper side of the female. 

 A little beyond the middle of the costa, on the hind wings, is an 

 irregular black spot on the upper surface, while the under surface is 

 pale lemon yellow without marks, but sprinkled more or less with 

 dark atoms. The body is black above and white beneath. 



Fig. 13. 



The caterpillars of this insect feed on the leaves of cabbage, cauli- 

 flower, turnip, mignonette, and some other plants. 



The female lays her eggs on the under side of the leaves of the 

 food plants, generally, but sometimes on the upper sides or even on 

 the leaf stalks. They are sugar-loaf shaped, flattened at the base, 

 and with the apex cut off square at the top, pale lemon yellow in 

 color, about one twenty-fifth of an inch long and one-fourth as wide, 

 and have twelve longitudinal ribs with fine cross lines between them. 



The eggs hatch in about a week, and the young caterpillars, which 

 are very pale yellow, first eat the shells from which they have 

 escaped, and then spin a carpet of silk upon which they remain 

 except when feeding. They now eat small, round holes through the 

 leaves, but as they grow older change to a greenish color with a pale 



