INVESTIGATION OF INSECTS. 568 
to compare a single individual with the descriptions of 
from 100 to 300 species a , to ascertain its name, seems 
enough to make you start aside with horror from the 
employment, and be content that your species should 
remain unnamed, rather than expose yourself to such a 
waste of time and patience. But to lessen your alarm 
and encourage you to proceed, I must observe to you, 
though in a few instances it may be necessary to ad- 
vert to the description of every single species in a sec- 
tion, yet that this is seldom requisite ; and where it is, 
there are many helps to diminish the labour and abridge 
the process. A large number of insects are characte- 
rized by their colour ; and it is the practice of all good de- 
scribers to begin their definition of the species with that 
which predominates, and then to enumerate the varia- 
tions from it. Thus, if an insect be all black except the 
thorax, antenna, and legs, you will find it thus charac- 
terized, " Black : with thorax, antennre, and legs ferrugi- 
nous "; and so on. Hence, having noticed the predomi- 
nant colour of your unknown species, in many genera 
you may compare it with the descriptions contained in a 
whole page at a single glance, and only read the further 
descriptions when the colour agrees. A practised Ento- 
mologist will thus investigate his insects with a rapidity 
which to an unlearned bystander would seem impossible. 
Though I have instanced colour as being the character 
most commonly employed in describing species of in- 
sects, you will readily conceive that in some tribes other 
characters afford more prominent distinctions. Thus in 
* In Elatcr, Fabricius describes 137 species j in MefoUmtha, 14!) ; 
in one section of Itht/ncha-mts, 161 ; of Curculio, 18.'5 ; and in his P«- 
piliones Helicami, .'500. 
2 o 2 
