35 
side of the leaves, often a score or more upon a single leaf. These 
eggs are greenish white in color, and stand at right angles to the 
surface. To an in experienced person they, might seem to be eggs of 
some fly, or the result of a disease of the leaf itself, but they would 
not be suspected to be the eggs of any butterfly. 
“In four or five days the young larvas emerge, one tenth of an inch 
in length, green in color, requiring a keen sight to discover them. 
At once they attack the leaf eating a small hole, and to the margin 
of this they, return when disposed to feed, till all the surrounding 
parts are eaten away. The large leaves of horse-radish may be entire¬ 
ly consumed in this way leaving but the skeleton untouched. 
“When at rest the larvae lie extended upon the surface of the leaf, 
generally along one of the ribs or in a depression, and as they re¬ 
tain their green color to maturity they are effectually screened from 
notice. When mature they are about one inch in length, cylindrical, 
covered with fine white papillae from each of which is emitted a sin¬ 
gle short hair. The chrysalids are brownish white marked ,anteriorly 
by a few points and short lines of black, and are distinguishable 
from those of any other genus by angular ridges on the back of the 
wing covers and head. They may be attached to fences aud build¬ 
ings near the food plant or to the plants themselves. This discre¬ 
tion will apply either to Oleracea or Hapce which, in both larval and 
chrysalis states are extremely alike. And doubtless will be found 
to apply as well to the same stages of Virginiensis .” 
The larvae of Napi and Oleracea and of all their varieties, so far as 
known, feed on the leaves of cabbage, turnips, radish, mustard and 
other cruciferous plants. Those of the Hapce and its varieties feed on 
cabbage, turnips, horse-radish, mignonnette and some other plants. 
A few words in reference to the characteristics and habits of some 
of the more noted foreign species may be of some advantage in this 
connection. 
P. brassic^e, Linn. 
Which has so long been noted in Europe as the foe of the cabbage 
is thus described: 
Both sexes have the upper surface of all the wings white, with the 
tips of the anterior wings above, black, the patch on its inner edge 
being indented, the points of the indentations following the direction 
of the nervures, and the extreme tip being slightly irrorated with 
white, with the cilia waved with black and yellowish; the female has 
also two roundish transverse spots on the disc, and an elongate trian¬ 
gular one on the inner margin of the wing; the costa and base of 
the anterior wings are irrorated with dusky, and sometimes tinged 
with yellowish; and the posterior wings have a black costal spot; 
the under surface of the anterior wings in both sexes is similar; 
the tips being yellowish, the base slightly irrotated with dusky, and 
two transverse spots adorning the disc: the posterior wings are pale 
yellowish beneath, with a very obsolete costal spot, and are rather thickly' 
sprinkled with dusky, especially in the female; the body and antennae 
are black above, and white beneath, the latter having an interrupted 
brown line from the base to the eapitulum, which gives them the 
appearance of being annulated, the eapitulum itself is yellowish at 
the tip. t (Stephens.) 
