CHAPTEK II. 



ON THE EXTERNAL STRUCTURE OF INSECTS. 



IT is not proposed to enter into any elaborate account 

 of the anatomy of insects, and many things usually con- 

 sidered to be of the alphabet of Entomology, will 

 be omitted in this chapter. Much of this however, 

 laborious and uninteresting if studied first in descrip- 

 tions, is acquired gradually, without trouble, and indeed 

 almost unconsciously, as the various species of insects 

 come, one by one, under the notice of the student. A 

 short account therefore of such parts only as it is 

 absolutely necessary to know by name will be given, 

 with familiar examples, in the hope that the reader will, 

 if possible, examine for himself every insect named, and 

 observe for himself many things not noted here. 



The name Insect (as also the Greek tWo/za, entoma, 

 whence " Entomology ") is given on account of the cut, 

 or divided character of the body. The body consists of 

 a series of joints, or rings, called segments. These 

 are soldered together so as to be with difficulty distin- 

 guishable in some parts of the body, but are usually 

 very evident in the abdomen. The perfect insect is 

 divided into three principal parts : the head, formed of 

 one, or, as some say, of more than one segment; the 

 thorax, to which the wings and legs are attached, and 

 which is composed of three segments closely united ; and 

 the abdomen, in which the number of segments varies, 

 nine, or possibly ten being the highest number found. 



