UTILITY OF INSECTS. 
19 
in the instrumentality of a large proportion of insects in their character 
of scavengers, whereby the decomposition of decayed and offensive 
matters, both animal and vegetable, is effected and accelerated ; and 
thirdly, in the agency of insects in causing the fertilization of plants, 
especially those with very deep corrollas, and those which have the bar- 
ren and productive flowers upon different plants, by carrying upon their 
legs, in their search for honey, the fertilizing pollen from one llower to 
another. A long chapter might be written upon each of these topics, 
but we have space here barely to enumerate them. 
DIVISION OF INSECTS ACCORDING TO THE NATURE OF THEIR FOOD. 
From this point of view all insects may be divided into two classes — 
the carnivorous insects, or those which eat animal food, (Sarcophaga ) ; 
and the herbivorous insects, or those which subsist upon vegetable sub- 
stances, (Phytophaga). Each of these classes is again divisible according- 
ly as the insects which compose it take their food in a fresh and living 
state, or in a state of decay. The former are called predaceous insects 
( Adephaga ), when they live upon animal prey ; and the latter are desig- 
nated by the name of scavengers ( Tigpophnga ). Those insects which eat 
living animal food, are still further divisible into predaceous insects 
proper, which seize and devour their prey, and parasite insects, which 
live within the bodies of their victims and feed upon their substance. 
Those insects which feed upon decaying animal matter present three 
divisions : first, general scavengers, which devour particles of putrescent 
matter wherever they may be found ; second, those which live exclu- 
sively in or upon the bodies of dead animals, ( Necrophaga ) ; and thirdly, 
those which are found exclusively in animal excrement, ( Coprophaga ). 
The herbivorous insects may be divided in a similar manner into those 
which eat fresh vegetable food. ( Thalerophaga), and those which subsist 
upon vegetable matters in a state of decay, (Saprophagu). They can 
also be usefully classified according to the particular parts of tho plant 
which they devour, into lignivorous or wood-eating insects, ( Xylophaga ); 
the folivorous, or leaf-eating insects, (Phyllophaga) ; and the fructivor- 
ous, or fruit-eating insects, (Garpophaga). 
The above Greek terms in parenthesis have been used chiefly in con- 
nection with the insects of the Coleopterous order, in which these diver- 
sities of food-habits exist to a much greater extent than in any of the 
other orders, but the terms themselves are of general signification, and 
being very concise and comprehensive, they might, not improperly, bo 
used in Speaking of insects in all the orders, so far as they aie appli- 
cable. 
