DESCRIPTION AND CLASSIFICATION OF INSECTS. 



29 



number of the wings or organs of flight, as appears from the 

 derivation of the names given to the several orders. This ar- 

 rangement must be considered as representing the most marked 

 pecuHarities of each particular order, and susceptible of various 

 modifications as our knowledge of insect structure and analogies 

 increases ; it is in fact but one out of many systems which have 

 been proposed by entomologists, and is selected because it re- 

 cognizes many primary divisions which are employed in popular 

 descriptions, and which have been approved since the time of 

 Linnceus, their originator. 



40. The primary divisions are termed orders ; the orders are 

 divided into sections ; the sections into families ; the families 

 into genera, and the genera into species or individuals. As it 

 will be absolutely necessary to refer from time to time to the 

 differents parts or organs of an insect, the annexed diagram of 



Head. 



J-Tliorax. 



Abdomoti. 



