duly very small ones. The males also have 
a sort of beards, more beautiful thaii the an- 
tenjix or horns of the females ; the female is 
much stronger as well as bigger than the 
male, and not unfrequentlv, in case of danger 
l or disturbance, she flies away with him in 
time of copulation. On dissecting the female, 
her uterus affords an astonishing sight. The 
number of eggs in the tubes is amazing ; but 
these have not all the same figure; and in 
some species, as the silk-worm, !kc. the eggs 
are of a beautiful blue ; if any yellowish ones 
are seen among them, they are judged to be 
defective. 
The care of all the butterfly tribe to lodge 
their eggs in safety is surprising. Those 
whose eggs are to be hatched in a few weeks, 
and who are to live in the caterpillar state 
during part of the remaining summer, always 
lay them on the leaves of such plants as will 
afford a proper nourishment ; but, on the 
contrary, those whose eggs are to remain 
unhatched till the following spring, always 
lay them on the branches of trees and shrubs, 
and usually are careful to select such places 
as are least exposed to the rigour of the en- 
suing season, and frequently cover them from 
i it in an artful manner. Some make a general 
coat of a hairy matter over them, taking the 
hairs from their own bodies for that purpose; 
others hide themselves in hollow places in 
trees, and in other sheltered cells, and there 
live in a kind of torpid state during the whole 
\ winter, that they may deposit their eggs in 
1 the succeeding spring, at a time when there 
l will be no severities of weather for them to 
combat. The day butterflies only do this, 
and of these but a very few species; but the 
[ night ones, or phalamae, all, without excep- 
tion, lay their eggs as soon as they have been 
in copulation with the male, ana die imme- 
diately afterwards. 
It is well known, that the common and na- 
tural food of these creatures is the leaves and 
verdure of vegetables ; yet, as weak and 
harmless as they seem, they will many of them 
destroy their fellows whenever they get an 
opportunity. Mr. Reaumur gives us an in- 
stance of this in 20 caterpillars of the .oak, 
which he kept in a box with a sufficient quan- 
tity of their natural food; yet their numbers 
daily decreased, till at last there remained 
only one. ’T his is, however, only the case in 
some few species, the generality of these ani- 
mals being very peaceable, many species 
living together in the same place without mo- 
lesting one another. These species, how- 
ever, though freed from such dangers, are ex- 
osed to others of a much more terrible 
ind; the worms or maggots of several sorts 
of flies are frequently found about them, 
some preying upon their outside, others 
lodged within them under the skin, but both 
kinds eating the poor defenceless creature up 
alive. Those which feed on the outsides are 
easily discovered : the others are more hid- 
den ; and frequently the caterpillar, which 
seems very hearty and vigorous, and very 
•fleshy, will be found, upon opening, to be a 
mere skin, the internal parts being found to 
he all eaten away, and all the food that lie 
swallows serving only to feed a vast number 
■of worms, or maggots, which crawl about at 
liberty within him. These devouring worms 
are of many different species ; some being of 
the gregarious, some of the solitary kinds, 
jfrid some spinning webs of their own silk to 
Vol. I. 
E'RUCA. 
transform themselves in, others undergoing 
that change without any such covering. The 
beautiful cabbage-caterpillar is one of those 
unhappy kinds which frequently are infested 
with the gregarious kinds, large numbers of 
which spin themselves webs one after an- 
other, and afterwards come out in the shape 
of the parent-fly to whose eggs they owed 
their origin. 
These intestine enemies are a sure preven- 
tion of the butterfly’s appearing at its proper 
time; and as many of the former naturalists, 
who knew what butterfly to expect from a 
peculiar' species of caterpillar which they 
preserved, often saw a parcel of flies come 
out in the place of it, they having no idea 
that the fly had laid its eggs in the flesh of the 
poor creature, supposed that this was one ot 
its natural transformations, and that certain 
species of caterpillars sometimes produced 
butterflies, sometimes small flies. These, and 
many other destroyers, among which the 
birds are to be reckoned in the principal 
place, serve the purpose of preventing the 
too great number of these mischievous ani- 
mals. Their usual habitation being the leaves 
and flowers of plants, they are, in their feed- 
ing, much exposed to all those destroyers ; 
yet nature has taken care to preserve a great 
number, by making many of them so exactly 
of the colour of the leaves they feed on, that 
they are not easily distinguished from them ; < 
and by giving others a caution of keeping on 
the under part of the leaves, and being by 
that means out of sight. But some species 
are much less exposed, and of much more 
mischief to the plants they feed on, by de- 
vouring more essential parts of them. Of 
these some eat the roots, and others the inte- 
rior part of the trunk, destroying the vessels 
that imbibe, and those that distribute the 
juices. These are different from the common 
caterpillars in this, that their skin is much 
less rough and hard ; and these are secure 
from our observation, and in general from 
their great destroyers, the birds. They are 
not, however, absolutely safe from the com- 
mon dangers of the other species; for there 
is a kind of worms that find their food and 
habitation even in the bodies of these. The 
root-caterpillars, and those which live within 
the branches of plants, are much more easily 
found out. The roots of scrophularia, and 
the stalks of lettuces, and some other plants, 
afford caterpillars which seem all of the same 
species. Those found in the lettuces are ex- 
tremely plentiful some years, and destroy 
vast quantities of that plant. These usually 
have their first habitation in the stalk, near 
the root. 
Nothing is more surprising in insects than 
their industry; and in this the caterpillars 
yield to no kind, not to mention their silk, 
the spinning of which is one great proof of it. 
The sheaths and cases which some of these 
insects build for passing their transforma- 
tions under, are by some made with 
their own hair, mixed with pieces of bark, 
leaves, and other parts of trees, with pa- 
per, and other materials; and the struc- 
ture of these is well worthy our attention. 
Yet there are others whose workmanship, in 
this article, far exceeds these. There is one 
which builds in wood, and is able to give its 
case a hardness greater than that of the wood 
itself in its natural state. This is the strange 
horned caterpillar of the willow, ^hich is 
dig 
one of those that eat their exuvia?; This 
creature has extremely sharp teeth, and with 
these it cuts the wood into a: number of small 
fragments; these fragments it afterwards 
unites together into a case, of what shape it 
pleases, by means of a peculiar silk, which is 
no other than a tough and viscous juice, 
which hardens as it dries, and is a strong and 
firm cement. The solidity of the case being 
thus provided for, we are to consider, that 
the caterpillar inclosed in it is to become a 
butterfly; and the wonder is, in what manner 
a creature of this helpless kind, which lias 
neither legs to dig, nor teeth to gnaw with, is 
to make its way out of so firm and strong 
a lodgment as this in which it is hatched. 
The butterfly", as soon as hatched, discharges 
a liquor which softens the viscous matter that 
holds the case together ; and so its several 
fragments falling to pieces, the way out lies 
open. Reaumur judged, from the effects, that 
this liquor must be of a' singular nature, and 
very different from the generality of animal 
fluids; and in dissecting this creature in the 
caterpillar state, there will always be found 
near the mouth, and under the oesophagus, a 
bladder of the size of a small pea, full of a 
limpid liquor, of a very quick and penetrat- 
ing smell, and which, upon trial, proves to-be 
a very" powerful acid'; and among other pro- 
perties, which it has in common with other 
acids, it sensibly softens the glue of tire case, 
on a common application. It is evident that 
this liquor, besides its use to the caterpillar, 
remains with it in the chrysalis state, and is 
what gives it a power of dissolving the struc- 
ture of the case, and making its way through 
in a proper manner at the necessary time. 
Boerhaave adopted the opinion, that there 
are no true acids in animals, except in the 
stomach or intestines ; but this familiar in- 
stance proves the contrary. 
Another very curious and mysterious arti- 
fice is that by which some species of cater- 
pillars, when the time of their changing into 
the chrysalis state is coming on, make them- 
selves lodgments in the leaves of the trees, 
by rolling them up in such a manner as to 
make themselves a sort of hollow cylindric 
case, proportioned to the thickness of their 
body, well defended against the injuries of 
the air, and carefuily secured for their state 
of tranquillity. Besides these caterpillars, 
which iu this manner roll up the leaves of 
plants, there are other species which only 
bend them once, and others, which by means 
of thin threads, connect many leaves together 
to make them a case. All this is a very sur- 
prising work, but much inferior to this me- 
thod of rolling. The different species of ca- 
terpillars have different inclinations, not only 
in their spinning arid their choice of food, but 
even in their manners and behaviour one to 
another. Some never part company from 
the time of their being hatched to their last 
change, but live and feed together, arid un- 
dergo together their change into the 
chrysalis state. Others separate one from 
another as soon as able to crawl about, and 
each seeks its fortune single; and there are 
others -which regularly live to a certain time 
of their lives in community", and then sepa- 
rate, each to shift for itself, and never to meet 
again iir that state. 
Caterpillars -are very destructive to gar- 
dens, particularly those of two species. The 
one, that which afterwards- becomes- the corti- 
