204 CLASSIFICATION OF INSECTS. 



is complete ; and anisomorphous or anisomorpha, in which 

 there is great variation of metamorphosis, although a gene- 

 ral similarity of structure in the perfect state. The winged 

 insects are also divided into seven classes : the amorphous 

 insects comprise two of these minor classes, called Lepi- 

 doptera and Diptera ; the necromorphous insects comprise 

 two classes, Hymenoptera and Coleoptera ; the isomorphous 

 insects comprise two classes, Orthoptera and Hemiptera ; 

 and the anisomorphous insects have only a single class, 

 Neuroptera. 



It is of great importance to adhere to some fixed nomen- 

 clature of divisions, and to understand the various steps 

 as we mount from species to kingdoms. To recapitulate, 

 they are these : 1. Species; 2. Genus ; 3. Family; 4. Or- 

 der ; 5. Stirps ; 6. Class ; 7. Tribe ; 8. Province ; 9. King- 

 dom: and be it recollected, the number of the minor groups 

 constituting a major group, need make no variation in the 

 name of either group. 



It may be remarked, that all divisions have a tendency 

 to subdivide into the numbers four and seven ; in other 

 words, to contain four groups, three of which shall be 

 double groups, and one single group : this circumstance 

 has led to much argument as to the superiority of the 

 particular numbers, two, four and seven. Some writers 

 have also contended for the numbers three and five. The 

 relative position in which the objects of nature stand, has 

 been also the subject of great discussion ; some authors 

 contending that the system of nature is represented by a 

 straight line ; others, by the branches of a tree ; others, by 

 the circumference of a circle. No decision on either num- 

 ber or position has yet been made by naturalists ; indeed, 

 it is the general opinion, that no particular number or posi- 

 tion is constant in nature. 



The author ventured to suggest, in a little essay called 



