LEPIDOPTEROUS INSECTS. 17 
from the fact that they are very particular in the 
choice of their food ; and most of the butterfly tribe, 
while in their various conditions, will feed only on 
the plant on which they were brought into existence, 
or when in a perfect state, on the nectar of flowers. 
Last autumn, a box and several flowerpots, with 
mignionette, was covered with numerous caterpillars 
of the Papilio rhamni. I took many of these off, 
and put them into a tumbler, to feed and watch 
their progress as to growth and time of transforma- 
tion. Wishing to ascertain whether or not they 
would feed on any other plants than that on which 
they had been hatched, I allowed them to consume 
all the leaves, and when I supposed them very 
hungry, supplied them abundantly with lettuce, 
sour dock, and other vegetables ; but they refused 
them all, preferring to gnaw and totally consume 
the epidermis of the dry stalks, rather than take the 
proffered food, which, it would appear, was not their 
native aliment, and they would have died rather 
than taste any other. The moment that leaves of 
mignionette were introduced, they speedily found 
them out, and greedily devoured them. 
De Geer remarked the same thing; for he found 
that the larva of a Papilio, which inhabited both 
the sallow and poplar, would feed only on the trees 
on which they were hatched; for those produced 
on the sallow would rather die than eat the poplar, 
