LETTER LI. 
INVESTIGATION OF INSECTS. 
AN Entomologist who aspires to more than the cha- 
racter of a mere amateur, will not be content with fill- 
ing his cabinet with nameless objects for the sole amuse- 
ment of the eye ; but will also be anxious to acquire 
some knowledge of what he has collected, and to ascer- 
tain by what names, whether indicating their genus or 
species, they have been distinguished by scientific writers 
who have described insects either in general or those of 
particular districts. Thus only can he himself derive 
profit from any discoveries he may make, or contribute 
to the further progress of the science a . 
But in order to accomplish this object effectually, you 
must remember and practise the Onslow motto — Festina 
lente : — you must not be too eager to name your species, 
but begin first with grouping your collection. The only 
way to acquire, in any degree, a correct knowledge of 
the Natural System, or of the general plan of the Crea- 
tor, which is the primum and ultimum of true science, 
is by studying groups. The knowledge of species is in- 
deed indispensable for the registry of facts and other 
practical purposes, but the knowledge of groups leads 
a Compare what is said Vol. I. p. 47 — . 
