55 
yellow or pale yellow. Often the hind part of the body is paler than the 
fore part. Frequently the head, or the apical segment, or both, are 
pale yellow, the rest of the body being of the usual green hue. In¬ 
dividuals may sometimes be met with having the head dusky or 
black with dusky clouds. The neck is frequently tinged with red. 
Commonly a stripe along the middle of the back is more or less dis¬ 
tinct, of a deeper green color or blackish in places; and on each side 
of the back a similar stripe may be discerned, whilst low down on 
each side a whitish stripe is sometimes apparent. With a magnifying 
glass the body is perceived to be clothed with several short black 
hairs, which proceed from minute black dots, each of which is sur¬ 
rounded by a faint pale ring. These dots are symmetrically arranged, 
and are situated the same as in numerous larvae of moths, each of the 
segments of the body having four of them above, placed at the angles 
of an imaginary square, of which the anterior side is the shortest; 
while on each side are four other dots placed at the angles of an im¬ 
aginary rhombus, the upper and lower angles of which are very acute. 
There are numerous dpts on the neck, aud the head is commonly 
freckled with a number of dark brown dots. 
There are sixteen legs and the two first segments of the abdomen 
at first glance appear to be furnished with legs also, being bulged 
on their under sides, so as to touch the surface on which the worm 
stands. 
The chrysalis or pupa is one-fourth of an inch long by 0.05 in 
width. It is commonly of a white color, with large, deep black eyes 
situated inside of the base of the antennal sheaths. Quite frequently 
the white color is varied with umber-brown stripes, whereof there is 
one on each side of the back, with a very slender brown line between, 
upon the middle of the back. The wing sheath is brown upon the 
upper margin, with a brown stripe in the middle and a more slender 
one inside of it, parallel to each other, and both running into the 
marginal stripe, this last being prolonged upon the abdominal seg- 
mets to the tip. The sheath of the antennae and of the legs are also 
brown. These brown stripes remain upon the pupa skin after the 
moth has been hatched from it, but the black color of the eyes then 
disappears. 
The winged moth measures 0.30 in length to the tips of the closed 
wings, and these, when expanded, measure 0.58. It is of an ash-gray 
color. The fore wings are freckled with black dots on the disk and 
apex and have a common white stripe on their inner margin reaching; 
to the hind angle, which stripe is wavy upon its inner edge and near 
the middle of the wing is bordered by a dark brown streak; the fringe 
of these wings is traversed by one or more blackish lines which are 
parallel with the margin. The hind wings and also the undersides of 
both pairs are leaden-brown, glossy, and without any spots or dots. 
The antennae and the underside of the abdomen are white. This moth 
is somewhat variable in the depth of its color, being frequently dark 
gray, and the stripe on its wings is not always pure white and dis¬ 
tinct. 
• Facts so far as observed indicate that when this and its kindred 
species are favored with unusually dry weather at the date of their 
appearance in the larva state, the species suddenly becomes excessively 
multiplied, overrunning particular sections of country like an invading 
army. When I observed this cabbage worm a drouth was prevailing 
