ON THE TRIBES OF MANDIBULATA. 419 



opinion more erroneous in entomology, than to confound 

 the present species of investigation with the analytical 

 nicety of a Monograph. It is to be recollected that we 

 are now distributing animals into various groups upon 

 principles of knowledge, which the reader is supposed to 

 have already acquired by analysis. For this analysis, in 

 so much as it was necessary for the establishment in out- 

 line of the primary groups, he has been presumed to be 

 indebted to the assiduity and skill of comparative anato- 

 mists. But that still more minute and tedious examination, 

 which is requisite ere we can esteem the subdivisions of 

 these groups to be natural, remains yet to be attempted. 

 Until therefore we resort again to minute analysis, and 

 perhaps until this analysis shall have been extended to all 

 the beings which compose the group of Mandibulata, 

 little that is positively certain ought to be concluded with 

 respect to its subdivision. Nay, Uie safer way will be to 

 account much of the remaining synthesis in this Essay as 

 somewhat hypothetical. It is a misfortune which I fore- 

 saw would be the consequence of the plan of this investi- 

 gation being rather premature. And it is therefore my 

 intention, if any of the foregoing notions should be deemed 

 likely to promote the interests of Natural History, to in- 

 vestigate, at some future period, this same ground in de- 

 tail by the inverse method. It is sufficient, for the pre- 

 sent, if my aim should be perceived from the arrange- 

 ment of the following few crude facts, to which I was led in 

 the course of collecting materials for an Analytical Essay 

 on the Developement of Annulose Forms. 



These preliminaries being settled in order to prepare en- 

 tomologists for many mistakes that will no doubt hereafter 

 be detected in this and the following chapter, by means 

 2 E2 



