LEPIDOPTEROUS INSECTS. 15 
to live in. Providence has given it the faculty of 
spinning certain threads ; and, after selecting a leaf, 
it draws it together, by means of these, into a 
roundish hollow form, leaving for the most part an 
opening into the interior before and behind. The 
leaf, when thus drawn together, serves as a house 
or tent for the little creature, and at the same time 
furnishes it with food; and hence the longer it 
lives in it the more perforated it becomes. When 
at length it has gnawed so much of the leaf as 
renders it so full of holes that it becomes useless, the 
caterpillar quits it, and goes to another leaf, pro- 
ceeding in the same way as it did with the first. 
Accordingly, when we are desirous of finding these 
caterpillars, we must search for them on those 
nettle leaves which are drawn together. I may 
mention, however, that not more than one cater- 
pillar will be found on a single leaf. 
« The circumstance of hiding within a folded leaf, 
is not usual with every spiny caterpillar; and it 
appears to me, that this species does so, more from 
a peculiar liking to live solitary than from any fear 
of danger, inasmuch as they are exposed to no more 
danger or hardship than other spiny caterpillars, 
which roam about freely and openly on the leaves. 
This species, besides, is quite as hardy as the others, 
with respect to enduring cold and heat ; and they 
are as much persecuted by parasite flies, (Jchnew- 
monidee,) which lay eggs in their bodies, as are 
