260 
NATURAL HISTORY. 
Yet, while we are thus fixing the rank of a certain class 
of animals, it seems necessary to define the nature of those 
animals which are thus degraded. Definitions, in general, 
produce little knowledge ; but here, where the shades of 
nature are so intimately blended, some discrimination is 
necessary to prevent confusion. Tlie smallness of the ani- 
mal, for instance, does not constitute an insect ; for then, 
many of the lizard kind, which are not above two inches 
long, would come under this denomination ; and if the 
smaller lizards, why not the crocodile, which would be a 
terrible insect indeed? In the same manner, smallness, with 
a slow, creeping motion, does not constitute an insect; for, 
though snails might be called insects with some propriety, 
the whole tribe of sea shell-fish would then have equal 
pretensions, and a very troublesome innovation would be 
brought into our language, which is already formed. Ex- 
cluding such animals, therefore, from the insect tribe, we 
may define insects to be little animals without red blood , 
bones or cartilages, furnished with a trunk , or else a mouth , 
opening lengthwise, with eyes which they are incapable 
of covering , and with lungs which have their openings on 
the sides. This definition comprehends the whole class of 
insects, whether with or without wings, whether in their 
caterpillar or butterfly state, whether produced in the ordi- 
nary method of generation between male and female, or 
from an animal that is itself both male and female, or from 
the same animal cut into several parts, and each part pro- 
ducing a perfect animal. 
In a cursory inspection of the insect tribe, the first ani- 
mals that offer themselves are those which want wings, that 
appear crawling about on every plant, and on every spot of 
earth which we regard with any degree of attention. Those 
therefore that never have wings, but creep about till they 
die, may be considered as constituting the first class of in- 
sects. All these, the flea and the wood-louse only ex- 
cepted, are produced from an egg; and, when once they 
break the shell, they never suffer any further change of form, 
but continue to grow larger till they die. The second order 
of insects consists of such as have wings : but which, when 
produced from the egg, have those wings cased up in such 
a manner as not to appear. The third order of insects is 
of the moth and butterfly kind. The fourth order is of 
those winged insects which come from a worm, instead of a 
caterpillar, and yet go through changes similar to those 
which moths and butterflies are seen to undergo. To these 
tve add, as a fifth order, a numerous tribe lately discovered, 
