Packard ] INSECTS OE TIIE GAKDEN. 
13 
After all the insects interest ns most when we study their 
psychology and habits. From what little we know of their 
psychical endowments, we see enough to convince us that 
as physically they occupy a middle ground between ourselves 
and the lowest and simplest of animals, so in their instincts 
they seem to maintain a corresponding relation. They have, 
what is the common property of all animals, enough intelli¬ 
gence to meet the exigencies of life. They possess apparently 
like passions with ourselves, so much so that w r e find our¬ 
selves unconsciously judging of their actions by our own 
feelings. Hence to our senses they hate and love, show fear 
and revenge, enjoy their moments of repose from toil, engage 
in sports, carry on wars, live a hermit life or are gathered 
into commonwealths, and are capable, individually, of some 
degree of education. 
All this great diversity among insects in form and accom¬ 
panying adaptation of instinct and reason are subservient to 
the part these animals are 
to play in nature. There 
are no neutral,* non-com¬ 
mittal characters among 
insects. The agriculturist 
classifies them into two 
categories, the friends and 
foes of his crops—accord¬ 
ing as they are carnivorous 
or herbivorous ; and it is 
necessary for him to dis¬ 
tinguish carefully between 
them. This is often a difficult matter, for as we descend in 
the scale of animal life we find those broad lines of demarca¬ 
tion which separate animals of different habits growing less 
distinct. In some tribes which resemble each other so closely 
that only educated eyes can distinguish them, we have spe¬ 
cies of totally different habits. Thus the Hessian fly (Fig. 3) 
2 13 
Hessian Fly: a , larva; b, pupa. 
