vill INTRODUCTION. 
segments next the head, which are each furnished with a pair of true legs, there are two seg- 
ments without legs, the next four being each furnished with a pair of the above-named pro-legs ; 
then follow two segments without legs, succeeded by the last segment, to which is attached a 
final pair of pro-legs, frequently somewhat different in character to the other four pairs. 
This distribution is, however, not universal among the Caterpillars of Moths and Butterflies, 
though nearly so among the latter. The larve of some Moths, those called the Loopers, for 
instance, have the pro-legs differently disposed, and, among Butterflies, the onisciform Cater- 
pillars of some kinds must be mentioned, which, while they have the gaily coloured skin and 
markings of Caterpillars, have nearly the form of the Woodlouse, to which the term enisciform 
refers. 
The general appearance of Caterpillars is greatly varied by the nature of the skin, and the 
clothing or other appendages with which it is furnished. Some are nearly smooth and glossy, 
others have the skin of velvety texture, others are covered with small tubercles, surmounted by 
a black or coloured point, sometimes naked, but from which emerges frequently a slender fila- 
ment, or a tuft, more or less spread, of shining hairs ; others are entirely covered with a thick 
growth of richly coloured silky fur, or exhibit it arranged in a row of dense tufts, which appears 
as though cut off square at the top. But nearly all Caterpillars that are more or less clothed 
with hair are those of Moths, the Caterpillars of Butterflies (I am only speaking of British 
species) being more generally smooth, except when furnished with curious spines, such as those 
which distinguish the larva of the Peacock Butterfly and some others, to be spoken of in their 
proper places. 
The head of the Caterpillar is the only firm or horny part, being necessarily so on account 
of furnishing the leverage for the powerful jaws or mandibles, by means of which the toughest 
foliage is cut through and masticated. The mouth, in the larva, or caterpillar state of insects, 
is very similar to that of the perfect insect, with the remarkable exception of the larvee of Butter- 
flies and Moths. In the larvee of these the mouth is furnished, as before mentioned, with strong 
mandibles or jaws for the mastication of solid food, but in the perfect Butterfly nothing of the 
kind appears, the mandibles being replaced by the singular proboscis or trunk, the slender tube 
of which forms the only means by which the perfect Butterfly takes the little food he requires, 
which consists only of the delicate juices lying deep in the nectaries of flowers. Such is the 
contrast between the voracity of the Caterpillar, and the delicate appetite it exhibits in its 
perfected form. 
The eyes of Caterpillars are generally very minute, often only perceptible by the use of a 
microscope, and they are not always situate in or near the head. In the Caterpillars of Butter- 
flies they are generally six in number. Their distribution is various, but they are most frequently 
arranged in a circle. They are nothing like the exquisite facetted eyes of the perfect insect, but 
are merely simple globules, and disappear with the skin of the Caterpillar, like the pro-legs, 
leaving no trace in the perfect insect. 
Antenne or horns are slightly indicated in nearly all Caterpillars, in a minute rudimental 
state, but are often only visible by the aid of a powerful microscope. 
The breathing apparatus of Caterpillars consists in a series of small apertures, termed spi- 
racles, which are generally situated on each side of the body in a line just above the legs and 
pro-legs, and never occur in the head. These breathing apertures are generally surrounded by 
a distinctly marked iris of some bright colour, and are thus rendered tolerably conspicuous, 
though often very small. 
The means of defence of Caterpillars against their several enemies is exceedingly various, but 
want of space prevents me from enumerating them here. I may, however, state that some have 
the power of spinning a web, by means of which they allow themselves to drop from a branch, 
and remain suspended in some less exposed place, till the danger is past. Some drop to the 
