It is somewhat remarkable that, although considerably upwards of two thousand years have elapsed since the first system of insects was promulged, at least the first of which we have any knowledge, yet no attempt has hitherto been successfully made to improve it; from this perfection I think we may fairly conclude, that the philosopher of Stagira was not merely a man of extraordinary talent, but that he had made himself the repository of what had previously been saved of the learning of his forefathers, in a day when it will be recollected the printing press had no existence; and we have nothing to prove that entomology had not degenerated through the two thousand years previous to Aristotle, as it unquestionably did during the two thousand years subsequent to the time of that philosopher, when our own immortal countryman, Ray, revived the science, and laid the foundation of a regenerated lustre, which, perhaps, may eventually rival that diffused by the great Stagirite himself. Be this as it may, the systematist has no choice but to go back two thousand years for the primary outline, or classification of insects; and, I may add, nothing but a desire to make myself clearly understood, prevents my adopting the nomenclature, as well as the division of Aristotle. I shall, however, employ the more modern and less appropriate names for the present, hoping that at a future day an opportunity may occur of doing justice to the merits of that writer, whom we are all compelled to follow, or to forsake the path of truth.[20] [20] The learned authors of the _Introduction to Entomology_ have inserted a sketch of the Aristotelian system in that work, a reference to which will convince the reader that it is next to impossible for the entomologist to over-rate him. See _Introduction to Entomology_, Vol. IV. p. 433. The reader who does not understand exactly what animals constitute the sub-kingdom Insecta, may refer to the _Introduction to Entomology_, where he will find the subject fully and accurately investigated.[21] It would be a needless incumbrance of my subject to repeat these definitions here, but as I am unable to meet with any characters for classes, by which relations and differences can readily and conveniently be traced, I have been induced to add a few definitions to those already in use, which I am the more willing to do because they will be useful here without ever perplexing science by forsaking the pages of this essay. [21] Introduction to Entomology, Vol. III. pp. 1-51. Column headings legend: G: General character. R: Resemblance to Imago.