CHIEF ENTOMOLOGICAL CLASSIFICATIONS AND SYSTEMS. 021 



to arrange the animal world from this point of view, must not be con- 

 sidered as without its use, or wholly unsuccessful, although his propo- 

 sitions are not fully solved. 



352. 



We have still to explain the system which we have ourselves sketched, 

 and which we communicated partially in the introduction. To do this 

 we refer to the chapter upon the metamorphoses, where we gave our 

 arrangement of the entire animal kingdom, and the relation of insects 

 to other animals. We there discovered that its physiological character 

 was its organisation as a motive animal, that is, its division into seg- 

 ments and joints, but which were, however, collected into three chief 

 divisions. We do not find this division into three parts in any other 

 annulose animal ; and as we again find a similar separation in the most 

 perfect of the Vertebrata, we may conclude that insects are the most 

 perfect of all the Annulosa. To attain this most perfect grade insects 

 require a gradual development, which displays itself in their transition 

 through the earlier animal forms and organisations. This we deno- 

 minate their transformation, or metamorphosis. The more marked 

 the transformation the more heterogeneous is the individual in the 

 several stages of its existence ; and as all insects proceed from the 

 same point, those, necessarily, whose metamorphosis we call complete 

 must attain a higher grade than the rest, which transform themselves 

 incompletely. We thus obtain two chief groups among insects, which 

 we distinguish as Insecta ametabola and Insecta metabola, but in a 



O 



different sense to that understood by Leach. Both commence a new 

 development in the organisation of the mouth, as they at first exhibit 

 to us abortive setiform oral organs, only adapted to suction, but in the 

 higher grades these suctorial organs develope themselves into free 

 mandibles, with a lip covering them. Thus each group has Insecta 

 haustellata and Insecta mandibulata. Each o f these groups may then 

 be further subdivided according to the form of the larva, the structure 

 of the wings, and the entire internal organisation and these divisions con- 

 stitute their orders. We thus obtain an arrangement, the principles 

 of which are deduced from the idea of the entire insect, and which, as 

 this idea becomes separated according to its several characters and con- 

 stituents, it consequently necessarily and spontaneously forms itself by 

 the philosophical laws of thought. It is the following : 



