One of his most prominent excellencies, which led the way more than any thing else to a distinct knowledge of natural objects, was his giving definitions of his genera, or the groups that he distinguished by that name, since all preceding writers had merely made them known by the imposition of a name. His generic characters of insects were of two kinds: A shorter, containing the supposed essential distinction of the genus, given at the head of the Class; and another, generally longer, and including non-essentials, given at the head of the Genus. The first he denominated the essential, and the latter the factitious or artificial character. He did not do for insects what he did for Botany,—draw up what he has called the natural character of a genus, which included both the others, and noticed every other generic distinction[1391].

The older Naturalists used to treasure in their memories a short description of each species, by which when they wished to speak or write of it they made it known. Thus, in speaking of the common lady-bird they would call it "the Coccinella with red coleoptra[1392] having seven black dots." This enunciation of any object was at first called its Title (Titulus), and afterwards its Specific Name (Nomen specificum), and by Linné was restricted to twelve words[1393]. But as the number of species increased to remember each definition was no easy task; that he might remedy this inconvenience, he invented what is called the Trivial Name (Nomen triviale), which expressed any species by a single term added to its generic appellation, as Coccinella septem-punctata; and thereby conferred a lasting benefit on Natural History. This convenient invention has rendered it less necessary to restrict the Nomen specificum to twelve words: it is desirable, however, that the definition of a species should be as short as possible, and contain only its distinctive characters. In his definitions and descriptions Linné was often very happy; but sometimes, in studying to avoid prolixity, he forgets Horace's hint,

... "Brevis esse laboro Obscurus fio—"

and makes his definitions of species, without adding a description, so extremely short as to suit equally well perhaps a dozen different insects. The minor groups into which he has divided some of his Orders and Genera are sometimes natural, sometimes artificial. Those of the Coleoptera, from characters drawn from their antennæ (as is evident from his arrangement of the genera in that Order), are of the latter description; while those of his Aptera are more natural. The genera that he has most happily laboured in this respect are his Hemipterous ones of Gryllus, Cicada, and Cimex, and all his Lepidoptera. He had such a tact for discovering natural groups in general, that in him it seems almost to have been intuitive.

But in no respect were the labours of Linné more beneficial to the science and to Zoology in general, than when he undertook to describe the animals of his own country. His Fauna Suecica is an admirable exemplar, which ought to stimulate the Zoologists of every country to make it one of their first objects that its animal productions shall no longer remain unregistered and undescribed. Botanists have almost every where been diligent in effecting this with respect to plants, but other branches of Natural History have been more neglected. In his Systema Naturæ Linné attempted this for all the productions of our globe. The idea was a vast one; and the execution, though necessarily falling far short of it, did him infinite honour: and in it he has laid a foundation for his successors to build upon till time shall be no more.

Such were the services rendered to Entomology by the labours of the immortal Swede; services so extensive as well as eminent, that had they been the fruit of a whole life devoted to this single object, they would have entitled him to a high rank amongst the heroes of the science. But how much more astonishing are they when considered but as gleanings from his hours of relaxation, snatched from labours infinitely greater, the produce, as he himself tells us, of moments consumed by others in "venationibus, confabulationibus, tesseris, chartis, lusibus, compotationibus[1394]." It is not so much in original discovery that the merits of Linné lie,—though considered in this view they are pre-eminent,—as in the unrivalled skill with which he sifted the observations of his predecessors, separating the ore from the dross, and concentrating scattered rays of light into one focus.

This era produced other systematists who adopted various methods, but none that merit particular notice except Geoffroy and De Geer. The former in this view is principally celebrated as the author of the method generally adopted by modern Entomologists, of dividing the Coleoptera into primary sections, according to the number of the joints of their tarsi. This method, though in many instances, as was formerly observed[1395], it leads to artificial results, in others affords a clue to natural groups; it can only therefore be applied subject to frequent exceptions. Geoffroy's work[1396], which was published in 1764, was further serviceable by indicating many genera not defined by Linné.

GENERAL CLASSES.ORDERS.CLASSES.
I. Wings covered with scales. Tongue spiral. Lepidoptera.
II. Wings membranous, naked. Mouth without teeth or tongue. Trichoptera. Ephemerina.
I. Four Wings without wing-cases III. Wings membranous, equal, reticulated. Mouth with teeth. Rest of Neuroptera.
IV. Wings membranous unequal, nervures mostly longitudinal. Mouth with teeth. A sting or borer in the female. Hymenoptera.
V. Wings membranous. Tongue bent under the breast. Homoptera.
I. Having wings VI. Elytra half coriaceous and half membranous, crossed. A pair of membranous wings. Tongue bent under the breast. Hemiptera Leach.
II. Two Wings covered by two wing-cases VII. Elytra coriaceous or semicrustaceous, aliform. A pair of membranous wings. Mouth with teeth. Orthoptera.
VIII. Elytra hard and crustaceous. A pair of membranous wings. Mouth with teeth. Coleoptera.
Insects III. Two Wings uncovered IX. A pair of membranous wings. A pair of poisers. Mouth with a tongue without teeth. Diptera.
X. A pair of membranous wings. No poisers, tongue, or teeth in the male. No wings but a tongue in the breast of the female. Coccus L.
IV. Undergoing a metamorphosis XI. No wings. Six legs. Mouth with a tongue. Aphaniptera.
II. Without wings
XII. No wings. Six legs. Head and Trunk distinct. Hexapod Aptera, Termes, Psocus.
V. Undergoing no metamorphosis XIII. No wings. 8 or 10 legs. Head united to the trunk. Octopod Aptera, Arachnida, Crustacea.
XIV. No wings. 14 Legs or more. Head separated from the trunk. Polypod Aptera. Crustacea.