ORDER IV.—MOTHS AND BUTTERFLIES. 133 
colors, and even the plainest looking will appear handsome 
upon a close examination with a magnifying glass. The 
size of their bodies varies very much in proportion to the 
size of the perfect insect, and their exterior surface is either 
smooth, as that of the Asterias on the parsnep (Fig. 29), or 
that of the Danaus on the milk-weed, or it is hairy like that 
of the Saturnia (Fig. 26) on Indian corn and other grasses. 
The food of caterpillars, with a few exceptions, is taken 
from the vegetable kingdom. Some feed exclusively on one 
species of plant, as the silk-worm on the white mulberry ; 
others on all the species of one genus, as the potato worm 
on the tomato, potato, etc.; others eat any kind of vege- 
table, as the woolly-bear (Arctia). The periods of taking 
their meals is also different; some eat only in the morning 
and evening; others during the whole day; and others only 
at night, while they conceal themselves during the day, and 
their depredations only are visible. But if by night we ex- 
amine our cabbage, cauliflowers, and turnips with a lan- 
tern, we shall often find them covered with a host of these 
noxious individuals. 
Many of the caterpillars live like hermits, a solitary life, 
and pay no attention to their brothers and sisters; while, on 
the contrary, many species are real socialists, and build in 
common their comfortable silk dwellings, with which, if not 
prevented by man, they sometimes cover entire trees. Here 
they. live, and feed together at regular hours; as, for in- 
stance, the Tent Caterpillar (Clistocampo Americana, Har- 
ris) on apple, pear, or cherry trees, and by such confrater- 
nities the trees of an entire orchard are ruined, unless the 
destructive intruders are destroyed in April or the begin- 
ning of May. 
Single parts of Caterpillars. 
Hrapv.—The head of a caterpillar is horny, of a globular 
or oblong form: it contains a mouth with an upper and 
