34 ° 
OF INSECTS IN GENERAL. 
by a poifer fituated under each wing, the bafe of which 
is covered by a fmall fcale, and the extremity terminates 
in a knob. 
The lall order comprehends in it all the apterous in- 
fefts, or fuc'n as are entirely deffitute of wings in either 
fex. 
In giving the hiftory of a clafs of animals fo ex- 
tremely numerous as that of infedts, it becomes abfo- 
lutely ncceffary to group them in certain tribes, whofe 
manners or external charadters correfpond : Nothing 
but this expedient can prevent endlefs confufion among 
fuch multifarious forms, or afford any profpect of finifli- 
ing a talk, that, at firil view, feems involved in fuch in- 
extricable difficulty. All naturalids who have treated 
of this part of the animal kingdom, have accordingly 
endeavoured to arrange them into orders and genera, 
Swammerdam and Ray feem to have founded their fyf- 
tems op the different changes which thefc animals under- 
go, and have formed them into four great divifions, a- 
greeable to the different forms under w'hich they appear; 
Valifnicri has alfo diftributed them into four orders, ac- 
cording to their habitation ; arranging together in one 
group, fuch as inhabit plants ; placing in another, thofe 
that live in the water ; and in a third, fuch as conceal 
themfelves under the earth or fand ; referving for his luff 
divifion, thofe that inhabit the bodies of other animals *. 
Both thofe fyftems are defective, in having too few divi- 
sions of a clafs of animals fo extremely numerous •, the 
laft, however, is liable to an imperfe&ion of another kind ; 
becaufe many infects change their habitation, at the mo- 
ment of their metamorpholis. Some are aquatic, which, af- 
ter 
Vide Kouvclle idee d’ene diviiion geijeraie des Infedte. 
