Sia oh a ae gt Sema) Bee Rt 
1876.] A Cosmopolitan Butterfly. II. Its History. 607 
particular instance laid them upon cut leaves lying on the ground ; 
in this case she laid them upon the uppermost surface, whichever 
way the leaf was turned; on the plant they are always laid upon 
the upper surface ; and I once found an egg on a spinous hair of a 
thistle leaf. Several eggs may sometimes be found on the same 
leaf, but they will always hatch at different times, showing that 
they were laid on different occasions, if not by different individ- 
uals. The egos themselves vary considerably, their vertical ribs 
ranging from fourteen to nineteen, and averaging fifteen and a 
half or sixteen in number; judging from the examination of forty 
or fifty specimens, it would seem as if the average were slightly 
greater in America than in Europe. 
The caterpillar feeds principally on Composite and especially 
upon the tribe of Cynarec, or thistles. In our country it has 
been found on Cnicus benedictus, Cirsium lanceolatum (the com- 
mon thistle), C. arvense, Carduus nutans, Silybum Marianum, 
nopordum acanthium, and Lappa major (burdock), — all plants 
introduced from Europe ; also on Senecio cineraria, belonging to 
another tribe of Compositæ ; on another of the Compositæ, one of 
the sunflowers, Helianthus sp. ; on Althæa rosea (garden holly- 
hock), — again an introduced plant, and one of the Malvacee ; 
and it is reported (perhaps by mistake for its congener, V. Ata- 
lanta) to have been found on the nettle. Möschler remarks that 
he has received neither thistles nor nettles from Labrador, and 
wonders upon what the caterpillar may feed in that inhospitable 
region. In Europe it has been taken upon various species of 
Carduus, Cirsium, and Onopordum, and other Cynaree, such as 
Centaurea benedicta and Cynara Seolymas ; some Senecionide, 
such as Achillea millefolium and Gnaphalium arvense; 1 on 
Echium, one of the Borraginacee, and on Malva rotundifolia. It 
Seems to prefer the Malwa in Egypt, being found abundantly on 
the species cultivated by the Arabs for medicinal purposes ; and 
since this is cut at various times during the winter, myriads of 
the caterpillar are doubtless annually exterminated. 
e young caterpillar makes its escape from the egg, as usual 
among lepidopterous larve, by biting a slit almost around the 
crown of the egg, and pushing up this improvised lid ; it does 
not appear to devour the egg-shell, as caterpillars usually do, 
t, after biting a few little holes partly through the upper sur- 
of the leaf, makes its way to the opposite side and takes 
up a position, each one apart from its fellow, either between the 
1 Horsfield, as we have seen, raised it in Java on Artemisia. 
