ENTOMOLOGIST'S TEXT-BOOK. 



INTRODUCTION. 



Entomology is that branch of zoology which treats of 

 the insect tribes, as restricted by the knowledge obtained 

 by the elaborate researches of modern comparative ana- 

 tomists. The term is derived from two Greek words, 

 entomon, an insect, and logos, a discourse ; the former word, 

 as well as the s3Tionymous Latin word, insectum, which we 

 have anglicised into insect, being themselves compounded of 

 other words, signifying a cutting or dividing into sections or 

 articulations, whence, in fact, Ave arrive at one of the great 

 characteristics of these tribes, namely, the articulated struc- 

 ture of the external parts of the body, which, being of a 

 corneous texture, serve as supports for the muscles and other 

 internal organs, just as the internal vertebrae of the higher 

 animals support the same parts ; so that in this class of 

 the invertebrated animals the external covering may pro- 

 perly be regarded as the skeleton. Now, this character, 

 joined to those derived from the respiratory, nervous, and 

 locomotive systems, tends to separate the true articulated 

 animals from a great number of other small creatures, with 

 which, under the common name of insects, they are classed 

 even in some of the latest popular compendiums of natural 



