550 INVESTIGATION OF INSECTS. 
to compare a single individual with the descriptions of 
from 100 to 300 species?, 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, antenne, and legs, you will find it thus charac- 
terized, “‘ Black: with thorax, antenne, 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 
2 fin Elater, Fabricius describes 137 species ; ‘in Melolontha, 149 ; 
in one section of Rynchenus, 161; of Curculio, 183; and in his Pa- 
pthones Heliconn, 300. 
