INVESTIGATION OF INSECTS. 563 



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, antenna, 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 



a In Elater, Fabricius describes 137 species; in Melolontha y 149; 

 in one section of Rhynchcenus, 161 ; of CurcuKo, 183; and in his Pa- 

 piliones Heliconii, 300. 



2 o2 



