After the very general idea that I have attempted to embody for you of the System of Insects; of the groups in which nature has arranged them, and their mutual relations; it will not be out of place, if I next state to you what has been effected by Entomologists towards reducing them to order: or, in other words, if I give you some account of the various Methods and Systems[1316], beginning with the earliest, that have appeared and had their day, which will include a history of the progress of our science from its commencement to its present era.

In writing the history of any science, two modes present themselves. We may either give a chronological review of all the circumstances and publications connected with it; or content ourselves with a rapid survey, dwelling only on the principal epochs, and those lights of the science who by their immortal labours gave birth to them. The latter is that on every account best suited to our present purpose, which I shall therefore here adopt.

There seem to me to be seven principal epochs into which the History of Entomology may be divided: viz. 1. The Era of the Ancients. 2. The Era of the revival of the science after the darkness of the middle ages. 3. The Era of Swammerdam and Ray, or of the Metamorphotic System. 4. The Era of LinnÉ, or of the Alary System. 5. The Era of Fabricius, or of the Maxillary System. 6. The Era of Latreille, or of the Eclectic System. And 7. The Era of MacLeay, or of the Quinary System. All of these appear to form important points, or resting-places, in the progress of the science towards its acme; and of each of these I shall now proceed to give you a brief account.

1. The Era of the Ancients. To ascertain what attention was paid to insects in the earliest ages, we must have recourse to the most ancient of records, the Old Testament. In this sacred volume we are informed that after the Creation God brought the creatures to Adam that he might name them[1317]. Now the first man, in his unimpaired state of corporeal, mental, and spiritual soundness, under the divine guidance, doubtless imposed upon them names significant of their qualities or structure; which according to Plato was a work above human wisdom, and on account of which the ancient Hebrews deduced that Adam was a philosopher of the highest endowments[1318]. Whether on this great and interesting occasion he gave names to individual species, or only to natural groups, does not clearly appear. But probably as they were created, so were they brought before him "According to their kinds[1319]."

Subsequently Moses will be thought to have possessed no ordinary knowledge of insects, if we suppose, as the ingenious remarks of Professor Lichtenstein[1320] render probable, that he distinguishes as clean insects the Fabrician genera Gryllus, Locusta, Truxalis, and Acheta, which a person unobservant of these animals would have confounded together. This discrimination presupposes this knowledge of their general characters, not only in the Jewish lawgiver, but also in the people themselves to whom the precept was addressed, to whom it would otherwise have been de ignotis.

Allusion is made in Holy Writ to insects of almost every one of the modern Orders[1321]. They are represented as employed divinitÙs sometimes to annoy the enemies of the Israelites, and at others to punish that people themselves when they apostatized from their God. The prophets frequently introduce them as symbols of enemies that lay waste or oppress the church: as the fly of the Ethiopians or Egyptians; the bee of the Assyrians; and the locust of the followers of Mahomet and other similar destroyers[1322]. That Solomon, amongst other objects to the investigation of which his divinely inspired wisdom directed him, did not deem insects, those "Little things upon the earth[1323]," unworthy of his attention, we know from Scripture[1324]; but as his physical writings are lost, we are ignorant whether he treated of their natural arrangement, their economy and history, or of the instruction they afford analogically considered. Where he has referred to them incidentally, it is generally with this latter view.

If we turn from the word and people of God to the Lovers of Wisdom (as they modestly styled themselves) of the heathen world, and their writings; we shall discern amongst them a great light shining, the beams of which illuminate even our own times. In the illustrious Stagyrite we recognize—"The father of philosophy, at least of our philosophy, who, rising superior to the darkness in which he lived, darted his penetrating glance through all nature, and established principles which a long course of ages of inquiry have but confirmed. With Aristotle begins the real History of science: and how much soever he may have erred upon particular points, the greatness of his conceptions and the justness of his ideas, on the whole entitle him to our high veneration. His labours in the investigation of the Animal Kingdom have laid the foundation of the knowledge we now possess[1325]." This language of the lamented and learned President of the Linnean Society is particularly applicable to what this great and original genius has effected in Entomology. We have seen upon a former occasion[1326], that LinnÉ himself had not those precise ideas of the limits of the Class Insecta, which Aristotle so many centuries before him had adopted. In stating the obligations of Entomology to this true sÇavant, I shall begin by laying before you a tabular view of what may be called his system, as far as I have been able to collect it from his works, especially his History of Animals.

				Coleoptera[1327].
				Pedetica = Orthoptera saltatoria Latr.[1328]
				Astomata = Hemiptera Latr.[1329]
		Pterota vel Ptilota[1331]		PsychÆ = Lepidoptera[1330].
				Tetraptera		majora = Neuroptera L. Orthoptera cursoria Latr.[1332]?
						Opisthocentra = Hymenoptera[1333].
				Diptera[1334]		minora = Musca, Tipula, &c.
						Emprosthocentra = Culex, Stomoxys, Tabanus, &c.
Insecta		Pterota simul et Aptera[1335]		Myrmex = Formica L.
				Pygolampis = Lampyris L.
		Aptera[1336].

It may be further stated, that Aristotle perceived also the distinction between the Mandibulata and Haustellata of modern authors: for he observes, that some insects having teeth are omnivorous; while others, that have only a tongue, are supported by liquid food[1337]. He appears to have regarded the Hymenoptera, or some of them, as forming a third subclass; since he clearly alludes to them, when he says that many have teeth, not for feeding, but to help them in fulfilling their instincts[1338].

From the above statement it will appear that this great philosopher had no contemptible notion,—though he has only distinguished three of them as larger groups by appropriate names,—of the majority of the Orders of Insects at present admitted. His Coleoptera, PsychÆ, and Diptera are evidently such. His idea of Hemiptera seems taken solely from the Cicada or Tettix: but the manner in which he expresses himself concerning it, as having no mouth, but furnished instead with a linguiform organ resembling the proboscis of Diptera[1339], proves that he regarded it as the type of a distinct group. Since he considers the saltatorious Orthoptera as forming such a group, it is probable that he included the cursorious ones with the Neuroptera in his majora section of Tetraptera; and the resemblance of many of the MantidÆ to the Neuroptera is so great, that this mistake would not be wonderful. His division of the Diptera is quite artificial.

How far Aristotle's ideas with regard to genera and species attained to any degree of precision, is not easily ascertained: in other respects his knowledge of insects was more evident. As to their anatomy, he observes that their body is usually divided into three primary segments,—head, trunk, and abdomen; that they have an intestinal canal,—in some straight and simple, in others contorted,—extending from the mouth to the anus; that the Orthoptera have a ventricle or gizzard[1340]. He had noticed the drums of Cicada, and that the males only are vocal. Other instances of the accurate observation of this great man might be adduced, but enough has been said to justify the above encomiums. His principal error was that of equivocal generation.Little is known with regard to the progress of other

Greek Naturalists in entomological science. It appears probable, from an epithet by which Hesiod distinguishes the spider—air-flying[1341], that the fact of these insects traversing the air was at that time no secret. Apollodorus, as we learn from Pliny[1342], was the first monographer of insects, since he wrote a treatise upon scorpions, and described nine species. But like many other Zoologists, by mistaking analogy for affinity, he has included a winged insect, probably a Panorpa, amongst his scorpions. From the time of Aristotle, however, to Pliny, no writer is recorded, with the exception of those before alluded to[1343], that appears to have attended much to insects. They are indeed incidentally noticed by Theophrastus, Dioscorides, Virgil, Ovid, &c., but without any material addition to the stock of entomological knowledge bequeathed to us by the Stagyrite. Even Pliny's vast compendium, as it professed to be, of the natural history of the globe, was in many respects little more than a compilation from that great philosopher. Still, however, though he does not appear to have paid much practical attention to insects,—which indeed, considering the extent of his views, was scarcely to be expected,—yet as a guide to the then state of entomological knowledge, and as an advocate for the study, which in the exordium of his eleventh book he has so eloquently and with so much animation defended from the misrepresentations of ignorance, Pliny has conferred a lasting obligation on the science. The last zoological writer of note was Ælian, who amongst other animals often mentions insects. He has, however, few original observations. One was, that scorpions are viviparous[1344]. From him we learn incidentally that artificial flies were sometimes used by Grecian anglers[1345].

2. The Era of the Revival of the Science. From the time of Pliny and Ælian 1400 years rolled away, in which scarcely any thing was done or attempted for Entomology or Natural History in general. During that long night the glimmer of only one faint luminary appeared to make a short and feeble twilight. In the middle of the thirteenth century Albertus Magnus (so called from his family name of Groot, and justly, if incredible labour could entitle a man to the appellation), devoted one out of twenty-one folio volumes to Natural History. In this work he professes not so much to give his own opinions, as those of the Peripatetic philosophers[1346]. He occasionally, however, relates the result of observations made by himself, which prove him to have been no inattentive student of nature. He mentions a voyage that he made for the purpose of collecting marine animals, and that he found of them ten different tribes or genera, and several species of each. Amongst these he particularizes the Cephalopoda, the Crustacea, the testaceous Mollusca, and some of the Radiata and Acrita, &c.[1347] He gives a very correct account of the pitfalls of Myrmeleon. Insects he distinguishes, excluding the Crustacea, by the denomination of Anulosa (Annulosa), which he appears to employ as a known term[1348]. He also calls them worms, describing butterflies as flying worms, flies as fly-worms, spiders as spider-worms; and what is still more extraordinary, the toad and the frog, which he includes amongst his Anulosa, he calls quadruped-worms[1349]!! Though it may appear so absurd to speak of these animals as insects, yet he had perhaps a deeper and more philosophical reason for this than we may at first be disposed to give him credit for. This would be the case if he separated these from the other reptiles and placed them amongst insects on account of their metamorphoses, mistaking perhaps an analogical character for one of affinity[1350]. Some of the Annelida, as Filaria and Lumbricus[1351], he also regarded as insects. I cannot gather from his desultory pages that he had any notion of a systematical arrangement of his Anulosa.

After the taking of Constantinople by the Turks in the middle of the fifteenth century, the light of learning, kindled by those of its professors who escaped from that ruin, appeared again in the West. The Greek language then began to be studied universally; and in consequence of the coeval invention of the art of printing, various editions of the great works of the ancients were published: amongst the rest those of the fathers of Natural History. From the perusal of these, the love of the sciences of which they treated revived in the West, and the attention of scientific men began to direct itself to the consideration and study of the works of their Creator. In the latter part of that century, a work entitled the Book of Nature appeared in the German language, in which animals and plants were treated of and rudely figured; as they were likewise most miserably in Cuba's Ortus Sanitatis, published in 1485, in which insects and Crustacea were described under the three different denominations of Animals, Birds, and Fishes; so that but little profit was at first derived from the writings of Aristotle, Invertebrate animals not being then even honoured with

This unpromising and apparently hopeless state of the science proved, however, the dawn of its present meridian brightness.

The first attempt at a separate and systematical arrangement of insects subsequent to the times of Aristotle, was made in the ponderous volumes of Ulysses Aldrovandus, who, disregarding the Stagyrite, arranged insects according to the medium they inhabit, as you will see in the subjoined table:

Membranacea

Favifica.

Anelytra

Non Favifica.

Alata

Farinosa.

Pedata

Elytrota.

Terrestria

Aptera

Paucipeda.

Multipeda.

Insecta

Apoda.

Pedata

Paucipeda.

Aquatica

Multipeda.

Apoda.

This artificial and meager system, which mixed insects with Annelida, was adopted by Charlton and other authors; and even in the eighteenth century had a patron of great eminence, who, endeavouring to improve upon it, has rendered it still more at variance with nature and Aristotle: I mean the celebrated Vallisnieri, to whom in other respects, though in this he fell behind his age, the science was under great obligations. He divides insects into, 1. Those that inhabit vegetable substances living or dead. 2. Those that inhabit any kind of fluid and in any state. 3. Those that inhabit any earthy or mineral substances, dead bones, or shells. And 4. Those that inhabit living animals[1352].

The work that is usually called Mouffet's Theatrum Insectorum was produced in the present era, and was the fruit of the successive labours of several men of talent. Dr. Edward Wotton and the celebrated Conrade Gesner laid the foundation; whose manuscripts falling into the hands of Dr. Thomas Penny,—an eminent physician and botanist of the Elizabethan age[1353], much devoted to the study of insect,—he upon this foundation meditated raising a superstructure which should include a complete history of these animals; and with this view he devoted the leisure hours of fifteen years of his life to the study of every book then extant that treated of the science either expressly or incidentally, and to the description and figuring of such insects as he could procure; but before he had reduced his materials to order, in 1589 he was snatched away by an untimely death. His unfinished manuscripts were purchased at a considerable price by Mouffet, a contemporary physician of singular learning[1354], who reduced them to order, improved the style, added new matter, and not less than 150 additional figures; and thus having prepared the work for the press, intended to dedicate it to queen Elizabeth[1355]. Fate, however, seemed still to frown upon the undertaking, for before he could commit his labours to the press he also died, and his book remained buried in dust and obscurity till it fell into the hands of Sir Theodore Mayerne, baron d'Aubone, one of the court physicians in the time of Charles I., who at length published it, prefixing a Dedication to Sir William Paddy, baronet, M.D., in 1634; and it was so well received that an English translation appeared twenty-four years afterwards. The work thus repeatedly rescued from destruction was indisputably the most complete entomological treatise that had then appeared. And though the arrangement (in which there is scarcely any attempt at system) is extremely defective, the figures very rude, often incorrect, and sometimes altogether false,—yet as an introduction to the study of insects its value at that day must have been very considerable; and as a copious storehouse of ancient entomological lore, it has not even at present lost its utility.

One of the most remarkable works of the era we are upon was published at Lignitz in the year 1603, by Caspar Schwenckfeeld, a physician of Hirschberg, under the title of Theriotrophium SilesiÆ. This was probably the first attempt at a Fauna that ever was made. In it animals are divided into quadrupeds, reptiles, birds, fishes, and insects. The Crustacea, Mollusca, and Zoophytes, are included under fishes. He says of the SpongiÆ that they are moved by animalcula which inhabit them[1356]. Did he borrow this observation from Aristotle, or was it made by himself[1357]? It is singular that LinnÉ should never allude to this work. Goedart, who belongs also to this era, is stated to have spent forty years of his life in attending to the proceedings of insects[1358]. But after this long study, his principal use to the science was the improvement he effected in the drawing and engraving of them,—for his figures, though sometimes incorrect and sometimes fabulous, were far superior to those of his predecessors.

3. The Era of Swammerdam and Ray, or of the Metamorphotic System. The great men whose names are here united, as they were cotemporary, so they agreed in founding their respective systems of insects on the same basis. To the former, however, is due the merit of being the first who assumed the metamorphoses of these animals as the basis of a natural arrangement of them; upon which the latter, in conjunction with his lamented friend Willughby, erected that superstructure which opened the door for the present improved state of the science. Swammerdam's system may be thus expressed in modern language:

		Class i.	Metamorphosis		complete[1359] = Aptera L.[1360]
		ii.	———————		semicomplete	Orthoptera, Hemiptera. Libellulina, Ephemerina[1361].
Insects		iii.	———————		incomplete	Coleoptera, Hymenoptera, part of Neuroptera and Diptera[1362].
					obtected	Lepidoptera[1363].
		iv.	———————			Ichneumones minuti L.[1364]
						MuscidÆ, &c[1365].

It was a great point gained in the science to introduce the consideration of the metamorphosis, and to employ it in the extrication of the natural system: for though when taken by itself it will, as in the table just given, lead to an artificial arrangement, it furnishes a very useful clue when the consideration of insects in their perfect state is added to it. The tables contained in the Prolegomena to Ray's Historia Insectorum divide insects into those which undergo no change of form, and those which change their form. The arrangement of the former ?eta??f?ta was made by Willughby, who subdivided them into Apoda and Pedata. As the only insects included in the former section were the grubs of Œstri, the remainder being Annelida, they need not be included in our table. I have endeavoured to compress these tables into as small a space as possible, by using the Linnean terms for metamorphosis, and reducing Ray's tribes of Orthoptera, Hemiptera, and Neuroptera to their modern denominations.

Ray details at considerable length the various tribes belonging to the four classes of metamorphosis established by Swammerdam[1366]. Most of his tribes indicate natural groups of greater or less value: but some of his larger groups are artificial, as you will see by the mere inspection of the table.

Apoda

Terrestia[1367].

Aquatica.

Ametamorphota

Terrestia[1368]

Majora[1368].

Hexapoda

Minora[1369].

Aquatica[1370].

Pedata

Octopoda

Caudata[1371].

Non caudata[1372].

14-poda.

24-poda.

30-poda.

Terrestia

Cylindrica[1373].

Insecta

Compressa[1374].

Polypoda

Corpore tereti.

Aquatica[1375]

——— plano.

Bicaudata.

Orthoptera.

Heteroptera.

Metamorphosis semicompleta[1376]

Homoptera.

Libellulina.

Ephemerina.

Metamorphumena

Coleoptera.

Metamorphosis incompleta vel obtecta

Alis farinaceis[1377].

Anelytra

Diptera.

Gregaria et Favifica

Mellifica[1378].

Non Mellifica[1379].

Alis membranaceis

Metamorphosis coarctata

MuscidÆ et Ichneumones minuti L.[1385]

Apiformia[1380].

Vespiformia

Breviora[1381].

Tetrapter

Solitaria non Gregaria et Favifica

Augustiora[1382].

Papilioniformia[1383].

SeticaudÆ, seu Tripilia[1384].

This era produced several great and original geniuses, who enriched the science with a vast increment of real knowledge. The illustrious Zoologists whose names it bears,—the one by his dissections and anatomical researches, and the other by his concise and well drawn descriptions of numerous insects, by various interesting observations on their manners and characters, and by the purity of his latinity,—contributed greatly to its progress towards perfection. Leeuwenhoek also, the compatriot of Swammerdam, and Hooke of Ray, amongst other objects submitted to their powerful microscopes, did not neglect insects.—To the former we are indebted for the remarkable discovery that the flea belongs to those that undergo a metamorphosis. Ray had besides two coadjutors whose names ought not to be forgotten,—Willughby and Dr. Martin Lister. The former is characterized by his lamenting friend as one of the profoundest of naturalists, as well as one of the most amiable and virtuous of men. What advantage Entomology would have reaped from his labours may be inferred from the eminent services that he rendered that science, amongst other branches of Zoology, during his short life. It appears from Ray's Letters[1386], that he drew up a history of insects and exsanguia, which probably formed the groundwork of the posthumous Historia Insectorum of that author; concerning which he says, "The work which I have now entered upon is indeed too great a task for me: I rely chiefly on Mr. Willughby's discoveries and the contributions of friends[1387]." And indeed Willughby's name and initials occur so frequently in that work, that it may be esteemed their joint production. Lister by his various writings elucidated many points relating to insects; and he may be regarded as the first modern who observed that spiders can sail in the air. But the most important of his works, and that on which his fame as an Entomologist is principally founded, is his admirable treatise De Araneis; in which his systematic arrangement of these animals leaves far behind all former attempts, and rivals that of the best modern Arachnologists. His specific descriptions are drawn with a precision till then unknown; and each is headed by a short definition of the species, which he calls the Titulus, synonymous with the Nomen specificum of LinnÉ, whose canon of twelve words it rarely exceeds.

One of the most important events of this era was the complete exposure and refutation of the absurd doctrine of equivocal generation, which had maintained its ground in the schools of philosophy from the time of Aristotle. Our own immortal Harvey was the first who dared to controvert this irrational theory: and his dictum—Omnia ex ovo—was copiously discussed and completely established by two of the ablest physiologists that Italy has produced, Redi and Malpighi.

Previously to the publication of the Historia Insectorum, no other works of eminence, with the exception of Madam Merian's beautiful illustration of the metamorphosis of the insects of Surinam, made their appearance: but in the interval of twenty-five years, which elapsed between the publication of that work and of LinnÉ's first outline of his Systema NaturÆ, Entomologists became more numerous and active. In England the pious and learned author of the Physico and Astro-Theology was celebrated for the assiduity with which he studied insects; and in the former of these works has concentrated a vast number of interesting observations connected with their anatomy and history. No Englishman contributed more to the progress of Natural History, both as a writer and collector, than that disinterested physician and naturalist Sir Hans Sloane, whose extensive and valuable library and well-stored cabinets formed the original nucleus of the present vast collection of the British Museum. Amongst other departments, that of insects was not overlooked by him; and it is to be regretted that those which he had accumulated have either perished from neglect or are not accessible. Other Entomologists were eminent at this period in Britain. The principal of these were Petiver, Dale (to whom Ray bequeathed his collection of insects), Bobart, Bradley, and Dandridge; the last of whom, as Bradley tells us, delineated and described 140 species of spiders.

I must not omit here to observe that our Royal Society, the origin of which took place in this era, communicated a new and powerful impulse to the public mind in favour of Physical Science, and greatly accelerated the progress of Natural History. It acted not only as a centre of excitement which stimulated to exertion, but also as a focus to collect the scattered rays of light before they were dissipated. Insulated observations in every department of nature were thus preserved; and communications from the most eminent naturalists in various parts of Europe ornamented its Transactions. So that from the establishment of this illustrious Society, the triumphant march of Physical Science of every kind towards its acme may be dated.

4. Era of LinnÉ, or of the Alary System. We are now arrived at that period in the history of Natural Knowledge, especially of Entomology, in which it received that form, with respect to its general outline, which, amidst many lesser mutations, has been preserved ever since. Swammerdam had altogether deserted the system of Aristotle, and Ray mixed it with that of his predecessor. But a brilliant star soon appeared in the North[1388], which was destined to be the harbinger of a brighter day than had ever before illuminated the path of the student of the works of God. The illustrious philosopher whose name distinguishes this new era, imbibed a taste for Entomology almost as early as for Botany[1389]; and though the latter became his favourite, and absorbed his principal attention, he did not altogether neglect the former. In the first edition of his Systema NaturÆ, published in 1735, and contained in only fourteen folio pages[1390], he began to arrange the three kingdoms of nature after his own conceptions. But this initiatory sketch, as might be expected, was very imperfect; and with respect to insects, instead of an improvement upon his predecessors, was extremely inferior to what Ray had effected; for he puts into one Order (to which he gives the name of Angioptera) the Lepidoptera, Neuroptera, Hymenoptera, and Diptera. In this work, however, Generic Characters were first given. In successive editions he continued to improve upon this outline: in the fourth he finally settled the number and denominations of his Orders; and in the twelfth (uniting the Orthoptera, which he had at first considered as of a Coleopterous type, to the Hemiptera) also their limits. His system, being founded upon the absence or presence and characters of the organs for flight, is in some degree a republication of the Aristotelian, and may be called the Alary System.

				Superior		crustaceous with a straight suture				Coleoptera	1.
		4.				semicrustaceous, incumbent				Hemiptera	2.
				All		imbricated with scales				Lepidoptera	3.
Wings						membranous—Anus		unarmed		Neuroptera	4.
								aculeate		Hymenoptera	5.
		2.		Poisers in the place of the posterior pair						Diptera	6.
		0.		Or without either wings or elytra						Aptera	7.

In considering this table, it must strike every one acquainted with the subject, that although the assumption of a single set of organs whereon to build a system can scarcely be expected to lead to one perfectly natural, yet that the majority of the groups here given as Orders merit that character. The second indeed and the last require further subdivision, and concerning the fourth no satisfactory conclusion has yet been drawn. With regard to his series of the Orders, it is mostly artificial. LinnÉ has the advantage of all his predecessors in giving clearer definitions of his Orders, and in their nomenclature; in which he has followed the path first trodden by Aristotle.

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,

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.

We next come to one of the greatest names in Entomology, the celebrated De Geer, who united in himself the highest merit of almost every department of that science. Both as a systematist, anatomist, and physiologist, and as the observant historian of the manners and economy of insects, his MÉmoires pour servir À l'Histoire des Insectes are above all praise. His system[1397] is contained in a posthumous volume published in 1778[1398].

This system, though built upon the instruments of flight; in its ternary groups, equivalent to the Orders of LinnÉ, adds likewise the instruments of manducation, and is thus intermediate between that of LinnÉ and Fabricius, who perhaps from the consideration of it might derive the first idea of assuming the last-mentioned organs as the basis of a new method. But, though partaking of both, it is nearer to nature than either; and had its illustrious author laid less stress upon the number and substance of the organs of flight, it would probably have been as near perfection in this respect as most that have succeeded it. But following too strictly these characters, he has been led to place in different Classes, or rather Orders, insects that ought not to have been so separated,—as in the case of the two sections of the Hemiptera, and the CoccidÆ. In other respects the whole of De Geer's MÉmoires are a storehouse of valuable observations, in which he has furnished many a clue for threading the labyrinth of nature, and given most complete and interesting histories of the whole economy and habits of many tribes and genera,—as of the Trichoptera, Aphides, Ephemerina, &c.

In this latter department of the science a light shone during part of the era we are now considering, which eclipsed every one that appeared before it, and has scarcely been equalled by any one that succeeded it. The date of its first appearance, indeed, was a year before that of LinnÉ's first outline of his Systema NaturÆ before alluded to; but it may properly be regarded as belonging to his era, since it did not disappear till some years after that had begun. A volume indeed would scarcely suffice to do justice to the preeminent merits of Reaumur, as exhibited in his admirable MÉmoires pour l'Histoire des Insectes[1399]: I must therefore content myself with observing, that in judgement and ingenuity in planning his experiments; in patient assiduity in watching their progress; in the elegance of his language, and the felicity of his illustrations, he has rarely, if ever, been equalled. Every subject that he undertook was thoroughly investigated, and in the true spirit of philosophical inquiry. Every where you see him the same unprejudiced and profound observer, attached to no system, anxious only for truth and the advancement of science. If he has any fault, it is, perhaps, that of being sometimes too prolix; but we must recollect that from the nature of his subject much diffuseness was often necessary to render his meaning clear. A greater objection is his total inattention to all system, except with regard to Lepidoptera and their larvÆ[1400], so that it is often difficult to ascertain the insects whose history he gives. But with these exceptions, no observer of nature, who wishes his discoveries to be at once profound and interesting, can copy a better model or one nearer to perfection.

Next to that of Reaumur, the name of his admiring correspondent Bonnet may be mentioned. This great physiologist, though still more deficient in systematical knowledge[1401], was also an admirable observer of the economy and manners of insects. In this sense he became an Entomologist before he was seventeen years of age, in consequence of an impression made upon him by the account of the Antlion in that attractive work the Spectacle de la Nature. From verifying its wonderful history with his own eyes, he entered with enthusiasm upon the study of other insects, his observations on which he regularly communicated to Reaumur. Amongst other interesting inquiries, his experiments on that singular anomaly in nature the generation of Aphides[1402] do him the highest credit, and have set that question perfectly at rest[1403].

In another department of the science this period was distinguished by a work which may almost be deemed a prodigy. I am speaking of Lyonet's admirable treatise on the anatomy of the caterpillar of the Cossus,—a work which will uphold his reputation as long as Entomology shall be cultivated as a science, or the comparative Anatomist be delighted to trace the footsteps of Divine Wisdom in the gradually varying structure of animals. The plates to this publication, executed by the hand of its excellent author, are as wonderful as the work itself; and together, to use Bonnet's words, form a demonstration of the existence of God. It is infinitely to be regretted that the author of this incomparable monument of scientific ardour and patient industry should have died before the full completion of his anatomical description of the pupa and imago of the same insect; of which he had prepared a considerable portion of the manuscript, and engraved upwards of twenty of the plates[1404].

Numerous other writers in various departments of the science appeared during this era; but it would be useless to enter into a particular detail of their works and merits. I cannot however omit noticing, on account of his inimitably accurate and chastely coloured representations of Lepidoptera, Sepp's beautiful Nederlandsche Insecten, in which the whole history of these animals, from the egg to the fly, is described and portrayed. In our own country this era was distinguished by no entomological work of any great eminence. Albin, Wilks, and Harris produced the principal. Gould, however, without having any thing of system, gave an admirable account of English ants, which I formerly noticed[1405].

One of our first poets, the celebrated Gray, was also much devoted to Entomology. From his interleaved copy of the Systema NaturÆ, that venerable and able naturalist, Sir T. G. Cullum, Bart. copied the following characters of the genera of insects of LinnÉ, drawn up in Latin Hexameters, which he kindly communicated to me.

Coleoptera.

Alas lorica tectas Coleoptera jactant.

*

**

***

Hemiptera.

Lepidoptera.

Squamam alÆ, linguÆ spiram Lepidoptera jactant.

Neuroptera.

Rete alÆ nudum atque hamos Neuroptera caudÆ.

Hymenoptera.

Diptera.

Diptera sub geminis alis se pondere librant.

Aptera.

Aptera se pedibus pennarum nescia jactant.

During this era, and by the influence of LinnÉ, in the year 1739 the Royal Academy of Sciences at Stockholm was established, which did for Natural History in Sweden what our own Royal Society had done for it in England. Other societies, with a similar object, were formed in different parts of Europe, and were attended by similar good effects. At Paris, at Berlin, at St. Petersburg, at Moscow, at Turin, at Lisbon, &c., the lovers of Nature, at that time and subsequently, have associated for this purpose; and I may mention here, that I may not revert to the subject, the great Natural History association of our own country, The Linnean Society, named after the illustrious Swede, which was first instituted in 1788, and incorporated by royal charter in 1802. In the Transactions of this learned body, the Zoologist in general, and particularly the Entomologist, will find much useful information and many interesting observations connected with his science. This flourishing society consists at this time of above 600 members, of whom more than 500 are Fellows;—a gratifying proof how widely Natural History is cultivated in the British Empire[1406].

5. Era of Fabricius, or of the Maxillary System.—We are now arrived, if its consequences be considered, at one of the most important epochs of the science. Fabricius, a pupil of LinnÉ, who highly estimated his entomological acquirements[1407], thinking that the system of his master was not built upon a foundation sufficiently fixed and restricted[1408], conceived the idea of doing for Entomology what the latter had done for Botany. As the learned and illustrious Swede had assumed the Fructification for the basis of his system in that science, so the emulous and highly-gifted Dane, observing how happily those organs were employed as characters in extricating the genera of Vertebrate animals, assumed the instruments of manducation, far more numerous and various in insects, for the basis of a new system of Entomology; which, from the maxillÆ being principally employed to characterize the Classes or rather Orders, may be called the Maxillary System. De Geer, indeed, as we have seen above, had, in the majority of his Classes, to the organs of flight added the parts of the mouth: but Fabricius pursued the idea much further, and made the Trophi[1409], or Instrumenta Cibaria as he called them, the sole corner-stone of his whole superstructure. Though nothing seems to have been further from his intention than to follow Nature, since he complains that LinnÉ by following her too closely had lost the Ariadnean thread of system[1410], yet it is singular that, by building upon this seemingly narrow foundation, he has furnished a clue, by the due use of which, instead of deserting her, his successors have been enabled with more certainty to extricate her groups: since the parts in question being intimately connected with the functions and economy of these animals, where they differ materially, indicate a corresponding difference in their character and station.

The first outline of his System, I believe, appeared in his Systema EntomologiÆ published in 1775; and the last, in his Supplement to his Entomologia Systematica in 1798. In this the series and characters of his Classes (for so, after De Geer, he denominates his primary groups) were as follows:—

*

1. Eleutherata[1411]. (Coleoptera L.) Maxilla naked, free, palpigerous.2. Ulonata[1412]. (Orthoptera Oliv.) Maxilla covered by an obtuse galea or lobe.

3. Synistata[1413]. (Neuroptera L., excluding the Libellulina, and taking in Termes L. and Thysanura Latr.) Maxilla geniculate at the base and connate with the labium.

4. Piezata[1414]. (Hymenoptera L.) Maxilla corneous, compressed, often elongate.

5. Odonata[1415]. (Libellulina M^cL.) Maxilla corneous, toothed, two palpi.

6. Mitosata[1416]. (Myriapoda Leach.) Maxilla corneous, vaulted, not palpigerous.

**

7. Unogata[1417]. (Pulmonary Arachnida Latr.) Maxilla corneous, armed with a claw.

***

8. Polygonata[1418]. (Isopod and Branchiopod Crustacea Latr.) Palpi mostly six; MaxillÆ many within the labium.

9. Kleistognatha[1419]. (Brachyurous Decapod Crustacea Latr.) Many MaxillÆ without the labium, closing the mouth.

10. Exochnata[1420]. (Macrurous Decapod Crustacea Latr.) MaxillÆ many without the labium, covered by palpi.

****

11. Glossata[1421]. (Lepidoptera L.) Mouth with a spiral tongue between reflexed palpi.

12. Ryngota[1422]. (Hemiptera Latr.) Mouth with a rostrum, having a jointed sheath.

13. Antliata[1423]. (Diptera L., Anoplura Leach., Trachean Arachnida Latr. &c.) Mouth with a haustellum without joints.

The Orders of Fabricius are equivalent usually to the primary groups of the Linnean Orders, and are regulated chiefly by the antennÆ.

In estimating the value of the above system, we must bear in mind that, according to the statement of its author, it was intended to be partly artificial and partly natural: artificial as to its Classes and Orders; natural as to its genera, species, and varieties[1424]. He admitted, however, that natural Classes, &c. do exist; but he contended that artificial ones should be substituted for them, till further discoveries had cleared the way for their satisfactory development[1425]. As therefore his system, in its primary and secondary groups, was confessedly artificial, and the only use of an artificial system being to facilitate the study of any department of Natural History, its value must be estimated by the facilities it affords to the entomological student. But here, it must be allowed, that instead of enlarging the entrance to the temple of his science, it has made it narrower, and has placed most discouraging impediments in his way.If you examine the definitions of his Classes, you will find them in a variety of cases calculated rather to mislead than to instruct a learner. Thus that of the Eleutherata would equally well suit the Piezata and several others: that of the Piezata is scarcely to be found in it; since in this the maxilla, instead of being corneous, is usually coriaceous[1426], and its lobe sometimes nearly membranous. In the Unogata he even mistakes the mandibles for maxillÆ. Let any young Entomologist endeavour to make out the Fabrician class of a Cicindela for instance; and finding its maxillÆ corneous and armed with a claw, he would conclude that it belonged to the Unogata rather than to the Eleutherata. Besides all this, the necessity of examining minute parts not easily come at without dissection, is very discouraging to a beginner.

From hence it is evident, that the system of Fabricius, considered as an artificial one or a method, was no improvement upon the classification of his master LinnÉ, but rather a retrograde movement in the science.

As to that part of his system in which he professes to take nature for his guide, his genera,—though even with respect to them he seems fearful of following her too closely[1427],—he certainly has rendered most essential services to Entomology, and laid the foundation of all that has since been done for its improvement. But it must be observed, that the series of his genera is often altogether artificial; as where he separates and places far asunder the Saprophagous and Thalerophagous Petalocerous beetles.Entomology, however, in other respects was deeply indebted to this great man. He first, as was lately observed, directed the attention of her votaries to parts which enabled them better to follow the chain of affinities, and to trace out natural groups. In his Philosophia Entomologica, drawn up on the plan of LinnÉ's Philosophia Botanica, he bequeathed to the science a standard work that ought to be studied by every Entomologist. His incredible labours in defining new genera and describing new species, with which view he travelled into various parts of Europe, and seven times into Britain, have been of infinite service[1428], and placed the science upon a footing much nearer to that of Botany than it had ever before attained.

6. Era of Latreille, or of the Eclectic System. The system of Fabricius, though generally adopted in Germany and Switzerland, did not meet with a universal reception. It seems to have gained no permanent footing in the North of Europe, Britain, or France. In the latter country the Linnean phraseology and characters of the Orders were retained by the celebrated Olivier; while at the same time his definitions of genera were constructed, after the Fabrician model, upon the antennÆ and the oral organs. But a new and brilliant genius had now appeared in France, whose indefatigable labours and singular talents have thrown more light over entomological science than those of all his predecessors. In 1796, about two years after Fabricius had completed his Entomologia Systematica emendata et aucta, M. Latreille published his PrÉcis de CaractÈres GÉnÉriques des Insectes; in which important work, walking in the steps of his great compatriot Bernard de Jussieu, he disregarded all artificial systems of Entomology, and attempted to construct one upon a natural basis: and to this end, uniting the consideration of the instruments of manducation with that of the organs for flight and motion, and of other external characters,—or the system of LinnÉ with that of Fabricius,—he became the founder of the modern or Eclectic system[1429]; for he judiciously adopted that sensible dictum of Scopoli, "Classes et Genera naturalia, non sola instrumenta cibaria, non solÆ alÆ, nec solÆ antennÆ constituunt, sed structura totius, ac cujusque vel minimi discriminis diligentissima observatio[1430]." His object has been in the above and subsequent works, by dividing his Classes into natural Groups, from the Order to the Genus, to trace out in all its windings, to its inmost recesses, the perplexing labyrinth of the true system of the Creator:—of what he has effected, the subjoined tables will give you a sufficient idea[1431].

1817.

Class.

Order.

Family.

Tribe.

Subtribe.

I. Crustacea.

TerritelÆ.

TubitelÆ.

SedintariÆ

InequitelÆ.

OrbitelÆ.

Araneides

LaterigradÆ.

PulmonariÆ

Vagantes

CitigradÆ.

SaltigradÆ.

PedipalpÆ

II. Arachnida

Scorpioides.

Pseudoscorpiones.

Entoma

TracheariÆ

Phalangita.

Holetra

Trombidites.

Acaridia

RiciniÆ.

HydrachnellÆ.

MicrophthirÆ.

1. Myriapoda

Chilognatha.

Chilopoda.

2. Thysanura

LepismenÆ.

PodurellÆ.

3. Parasita

Mandibulata.

Edentula.

III. Insecta

4. Suctoria.

5. Coleoptera.

6. Orthoptera.

7. Hemiptera.

8. Neuroptera.

9. Hymenoptera.

10. Lepidoptera.

11. Rhiphiptera.

12. Rhiphiptera.

1825.

		Class.		Order.		Family.		Section.		Tribe.
		I. Crustacea.
						Pedipalpi				Scorpionides.
										TarentulÆ.
				PulmonariÆ
								Tetrapneumones.
Hyperhexapi.						Araneides				TubitelÆ.
										InÆquitelÆ.
								Dipneumones		OrbitelÆ.
										LaterigradÆ.
		II. Arachnides.								CitigradÆ.
										SaltigradÆ.
						Pycnogonides.
						Pseudoscorpiones.
						Phalangita.
				TracheariÆ		Acarides.
						HydrachnellÆ.
						RiciniÆ.
						Microphthira.
Condylopa.				Chilognatha		Anguiformia.
		III. Myriapoda.				Penicillata.
						InÆquipedes.
						Æquipedes.
				Thysanoura		LepismenÆ.
						PodurellÆ.
		Aptera.
				Parasita		Mandibulata.
						Siphunculata.
				Siphonaptera.
Hexapoda.		IV. Insecta.
				Coleoptera
				Orthoptera		Elytroptera.
				Hemiptera
		Alata		Neuroptera
				Hymenoptera		Anelytra quadripennia.
				Lepidoptera
				Rhiphiptera		——— bipennia.
				Diptera

Having given you these tables of the Orders, from a comparison of which you will be able to trace the improvements in his system made by this learned Entomologist in the interval of eight years, I shall proceed to give those of his subordinate groups arranged under each. This I have already done, to save space, in the Arachnida and Insecta aptera.

Order.		Section.		Family.		Subfamily.		Tribe.		Subtribe.
								CicindeletÆ.
						Terrestres				Truncatipennes.
										Bipartiti.
				Adephagi				Carabici		Thoracici.
										Abdominales.
										Subulipalpi.
						Aquatica		Hydrocanthari.
								Gyrinites.
								Fissilabres.
				Brachyptera				Longipalpi.
								Depressi.
								Microcephali.
						Sternoxi		Buprestides.
								Elaterides.
				Serricornes
								Cebrionites.
								Lampyrides.
						Malacodermi		Melyrides.
								Clerii.
		Pentamera						Xylotragi.
								Ptiniores.
								Histeroida.
								Peltoides.
				Clavicornes				Palpatores.
								Dermestini.
								Byrrhii.
								Macrodactyli.
				Palpicornes				Hydrophilii.
								SphÆridiota.
										Coprophagi.
										ArenicolÆ.
Coleoptera								ScarabÆides		Xylophili.
										Phyllophagi.
				Lamellicornes						Anthobii.
										Melitophili.
								Lucanides.
								PimeliariÆ.
				Melasoma				Blapsides.
								Tenebrionites.
								Dioperiales.
				Taxicornes				Cossyphenes.
								Crassicornes.
		Heteromera						Helopii.
								Cistelides.
				Stenelytra				Securipalpi.
								Œdemerites.
								Rhyncostoma.
								LagriariÆ.
								Pyrochroides.
				Trachelides				MordellonÆ.
								Anthicides.
								Horiales.
								CantharidiÆ.

Order.		Section.		Family.		Tribe.
						BruchelÆ.
						Anthribides.
				Rhynchophora		Altelabides.
						Brentides.
						Curculionites.
						Scolitarii.
				Xylophagi		Bostrichini.
						Paussili.
						Trogossitarii.
				Platysoma.
						Prionii.
		Tetramera				Cerambycini.
				Longicornes		Necydalides.
						LamiariÆ.
						LepturetÆ.
				Eupoda		Sagrides.
						Criocerides.
Coleoptera
						CassidariÆ.
				Cyclica		ChrysomelinÆ.
						GalerucidÆ.
				Clavipalpi.
		Trimera		Aphidiphagi.
				FungicolÆ.
				Pselaphii.
		Monomera.
				Forficularia.
		I.		BlattariÆ.
				Mantides.
				Spectra.
Orthoptera
		II.		Gryllides.
				LocustariÆ.
		III.		Acridites.
						Longilabra.
						MembranaceÆ.
				GeocorisÆ		Nudicolles.
						OculatÆ.
		Heteroptera				Ploteres.
				HydrocorisÆ		Nepides.
						Notonectides.
Hemiptera
						Stridulantes.
				CicadariÆ		FulgorellÆ.
						Membracides.
						CicadellÆ.
		Homoptera
						Psyllides.
				Hymenelytra		Physapi.
						Aphidii.
				Gallinsecta.

Order.		Section.		Family.		Tribe.		Subtribe.
		Subulicornes		Libellulina.
				Ephemerina.
						PanorpatÆ.
Neuroptera						Myrmeleonides.
						Hemerobini.
				Planipennes		PsoquillÆ.
						TermitinÆ.
		Filicornes				RaphidinÆ.
						Semblides.
						Perlides.
				Plicipennes.
				Securifera		TenthredinetÆ.
						Urocerata.
		Terebrantia
						Evaniales.
						Ichneumonides.
				Pupivora		GallicolÆ.
						Chalcidites.
						Chrysides.
						Oxyuri.
Hymenoptera				Heterogyna		FormicariÆ.
						MutillariÆ.
						ScolietÆ.
						Sapygites.
						Pompilii.
				Fossores		Sphegides.
						Bembecides.
		Aculeata				LarratÆ.
						Nyssonii.
						Crabronites.
				Diploptera		VespariÆ.
						Masarides.
						AndrenetÆ.
				Mellifica				SolitariÆ.
								Andrenoides.
						ApiariÆ		DasygastrÆ.
								CuculinÆ.
								Scobulipedes.
								Sociales.
								Hexapoda.
						Papilionides		Perlata.
				Diurna				Argus.
						Hesperides.
						Hesper-sphinges.
				Crepuscularia		Sphingides.
Lepidoptera						ZygÆnides.
						Bombycites.
						Pseudo-Bombyces.
						Tineites.
				Nocturna		NoctuÆlites.
						Tortrices.
						PhalÆnites.
						Crambites.
						Pterophorites.

Order.		Section.		Family.		Tribe.		Subtribe.
						Culicides.
				Nemocera				Culiciformes.
								GallicolÆ.
						TipulariÆ		TerricolÆ.
								FungivorÆ.
								Florales.
						Tabanii.
						Sicarii.
						Mydasi.
						Leptides.
						Dolichopoda.
				Tanystoma		Asilici.
		I.				Hybotina.
						Empides.
						Anthracii.
						Bombyliarii.
						Vesiculosa.
				Notacantha		Xylophagei.
						Stratyomides.
Diptera						SyrphiÆ.
						ConopsariÆ.
						Œstrides.
				Athericera				CryptogastrÆ.
								CreophilÆ.
								CarpomyzÆ.
						Muscides		DolichocerÆ.
								GonocephalÆ.
								ScathophilÆ.
								ApterÆ.
		II.		PupiparÆ		CoriaceÆ.
						PhthiromyiÆ[1432].

If you examine the Orders as here given, you will find that they mostly represent natural primary groups of his Classes, though with regard to their distribution you may perhaps feel disposed to differ from him. You will also think that his secondary and minor groups[1433], with the exception of some of his sections, merit the same character. Indeed, he has left far behind all his predecessors in the progress that he has made towards extricating the true system. Setting out from a common centre he holds on his unwearied course, endeavouring to trace every set of objects that branches from it to its extreme term. But though he studied insects analytically with unrivalled success, he was not always equally happy in his synthetical arrangement of them. I do not here so much speak of the result which must necessarily follow from any arrangement in a series, and which cannot well be avoided; but I allude particularly to his intire adoption of the Geoffroyan system in the Coleoptera, which has prevented him in many instances from seeing the natural distribution of his groups.

In 1798, two years after the publication of Latreille's first enunciation of his system, M. Clairville, a very acute and learned Swiss Entomologist, drew up the following analytical table of insects.

						Sections.
						1. Elytroptera (Coleoptera).
				Mandibulata		2. Deratoptera (Orthoptera).
						3. Dictyoptera (Neuroptera).
		Pterophora				4. Phleboptera (Hymenoptera).
Insecta						5. Halteriptera (Diptera).
				Haustellata		6. Lepidioptera (Lepidoptera).
						7. Hemimeroptera (Hemiptera).
		Aptera		Haustellata		8. Rophoteira.
				Mandibulata		9. Pododunera.

Every one will think that the change of the received names of the Orders, here denominated Sections, is perfectly needless. The principal merit of this system is the division of insects, tacitly pointed out by Fabricius, into two groups or subclasses, from the mode in which they take their food.

Lamarck,—whose merits as a Zoologist, except in one point[1434], are of the highest order,—in his SystÈme des Animaux sans VertÈbres, which was published in 1801, adopts the above division of insects; but, after Aristotle[1435], he makes the Hymenoptera an intermediate Order between the masticators and those that take their food by suction; he places the Lepidoptera at the head of the latter, and the Aphaniptera, which he denominates Aptera, at the end[1436]: the Hexapod, Octopod, and Polypod Aptera he considers as Arachnida[1437]. In his last great work (Histoire Naturelle des Animaux sans VertÈbres) he includes the Hymenoptera amongst the masticators, and reverses the disposition of his Orders, beginning with his Aptera and ending with the Coleoptera[1438].

M. Le Baron Cuvier, in his Anatomie ComparÉe (1805) divided Insecta into two subclasses, from the presence or absence of maxillÆ: thus—

With MaxillÆ.	Without MaxillÆ.
1. Gnathaptera.	1. Hemiptera.
2. Neuroptera.	2. Lepidoptera.
3. Hymenoptera.	3. Diptera.
4. Coleoptera.	4. Aptera.
5. Orthoptera.

His Gnathaptera include the Isopod Crustacea, the Arachnida, the Polypod, and some of the Octopod and Hexapod Aptera; and his Aptera—Pulex, Pediculus, and the Acarina, with the exclusion of Hydrachna[1439]. It is remarkable enough that his Class as it stands, with a slight alteration, returns into itself, thus forming a circle; for his first Order (Gnathaptera) contains Hydrachna and the Thysanura, and his last (Aptera) ends with the Anoplura, and Acarina.

All the French Entomologists have followed Olivier and Latreille in adopting, with some variation, Geoffroy's system with regard to the Coleoptera, which has rendered them all more or less artificial. Dumeril has constructed a table of the Order, arranged differently from that above given[1440] of Latreille; but not more natural, for the very same reason.

Our learned countryman, Dr. Leach, by his zoological labours has thrown much light on the natural distribution of the Animal Kingdom, and no department of that kingdom is more indebted to him than the Annulosa; of which I have before stated to you his Classes[1441]. I shall now give a table of his Orders of Arachnida and Insecta Latr. and also his families, &c. of his Classes Myriapoda and Arachnides[1442].

Class.		Order.		Family.
				Glomerides.
		Chilognatha		Iulides.
				Polydesmides.
Myriapoda
				Cermatides.
		Syngnatha		Scolopendrides.
				Geophilides.
		Podosomata		Pycnogonides.
				Nymphonides.
				Sironides.
		Polymerosomata		Scorpionides.
				Tarantulides.
Arachnides
				Solpugides.
		Dimerosomata		Phalangides.
				AraneÏdes.
				Trombidides.
				Gammasides.
		Monomerosomata		Acarides.
				Cheyletides.
				EylaÏdes.
				Hydrachnides.
		Ametabolia		Thysanura.
				Anoplura.
				Coleoptera.
Insecta				Dermaptera.
				Orthoptera.
				Dictyoptera.
				Hemiptera.
				Omoptera.
		Metabolia		Aptera.
				Lepidoptera.
				Trichoptera.
				Neuroptera.
				Hymenoptera.
				Rhiphiptera.
				Diptera.
				Omaloptera.

I have before expressed my sentiments upon several of these Orders[1443]: I shall not here repeat them, but shall merely observe, with respect to those I have not adopted, that, though perhaps not entitled to rank as Orders, most of them form natural groups. His Orders, however, of Arachnida must be excepted from this remark, since they are evidently artificial. His analyses of his Orders, though in general they give natural groups, are usually not carried so far as those of M. Latreille, so as seldom to indicate what may properly be denominated families. He has made his nomenclature for his so-called families more uniform and satisfactory than that of the French Entomologist: and we may say, with respect to the extent and effect of his zoological labours,—Nihil non tetigit, et omnia quÆ tetigit ornavit.

7. Era of MacLeay, or of the Quinary System. I have more than once stated to you in my former letters the bases upon which the system which I am in the last place to explain to you is built. You know the Sub-kingdoms and Classes into which its learned and ingenious author, upon a novel and most remarkable plan, has divided the Animal Kingdom[1444]. I shall now copy for you his diagram of the Annulosa.

I have before sufficiently noticed these Classes, or Orders as Mr. MacLeay terms them, of the Sub-kingdom Annulosa: I shall here therefore only throw out a few remarks on their composition. With regard to their circular distribution in the Crustacea, Mr. MacLeay thinks the series runs from the Branchiopods or Monoculus L. to the Decapods or Cancer L.; and so on, till by means perhaps of the genus Bopyrus, which Fabricius regards as a Monoculus, it returns to the Branchiopods again. This circle, through Porcellio, a kind of wood-louse, &c., which has only a pair of antennÆ and at first but six legs, is connected with the Ametabola Class, which beginning with Glomeris goes by the other Chilognatha (Iulus L.), having also six legs at first, and certain Vermes to the Anoplura, and terminates in the Chilopoda (Scolopendra L.) their cognate tribe[1445]. From the Ametabola Mr. MacLeay proceeds to the Mandibulata, between which two groups he has discovered no osculant one, but he takes the Anoplura of the former as the transit to the Coleoptera in the latter; from whence passing to the Orthoptera, &c., he finally returns by the Hymenoptera. Between the Mandibulata likewise and Haustellata he finds no osculant class: but as the affinity between the Trichoptera and Lepidoptera is evident, proceeding by the Homoptera he returns to the Lepidoptera by certain Diptera, as Psychoda, &c. From the Aptera Lam. or Pulex L. he passes by the osculant class Nycteribida to the Arachnida; and beginning with the Acaridea, he goes to the Scorpionidea, and so to the Aranidea or spiders, which he connects with the Decapod Crustacea;—thus forming his great circle of five smaller ones, each of which, as well as that which they form, returns into itself[1446].

We next take his Circles of Mandibulata: thus—

In this arrangement of the tribes, as he calls them, of Mandibulata, Mr. MacLeay sets out from the Coleoptera, which he distributes, according to the supposed typical forms of their larvÆ, into five minor groups, sufficiently noticed on a former occasion[1447]. From this tribe or Order he proposes to pass by Atractocerus to the osculant Order Strepsiptera, and from thence by Myrmecodes and the Ants to the Hymenoptera. From hence he next proceeds to his Trichoptera; in which, as we have seen[1447], he places not only Phryganea L., but also Tenthredo L. and Perla Geoffr., making his transit by Sirex L.; forming an osculant Order which he denominates Bomboptera. From this his way to the Neuroptera is by the Perlides, with Sialis as an osculant Order under the name of Megaloptera: he enters by Chauliodes, and leaves it by Panorpa or Raphidia by means of Boreus, forming also an osculant Order (Raphioptera) for the Orthoptera; which he enters by Phasma, Mantis, &c., and leaves by Gryllus, entering the Coleoptera again by the osculant Order Dermaptera formed of Forficula L.: and thus returning to the point from which he set out[1448]. He has not, however, made this return of the series into itself so clear in each order, excepting in the Orthoptera, as he has done in the whole Class or Sub-class. Thus in the Coleoptera there appears no particular affinity between the Predaceous and Vesicant beetles, his first and fifth forms[1449], or his Chilopodimorphous Coleoptera, and his Thysanurimorphous.

To enter fully into his doctrine of Analogies would lead us into a very wide field, and occupy a larger space than I can afford; I must therefore refer you to his work for more particular and detailed information on that subject. With regard to the analogy between opposite points of contiguous circles, you may get a very good idea of it from his diagram of Saprophagous and Thalerophagous Petalocerous beetles, which I here subjoin.

It is a very singular circumstance that in these two circles we have two sets of insects,—one impure in its habits and feeding upon putrescent food, and the other clean and nourished by food that has suffered no decay,—set in contrast with each other, and that in each of the opposite groups, the one has its counterpart in some respect in the other. In none is this more striking than the ScarabÆidÆ and CetoniadÆ, both remarkable for having soft membranous mandibles unfit for mastication, and both living upon juices, the one in a putrescent and the other in an undecayed state[1450]. Our learned author in subsequent works has stated every circle to be resolvable into two superior groups, which he denominates normal or typical, and three inferior ones, which he calls aberrant or annectent[1451].

Before I conclude this account of the various general systems that have distinguished the different entomological eras, i must say a few words on those partial ones which have been founded on the neuration of the wings of insects. Frisch, who died in 1743, attempted something in this way[1452]: Harris, in his Exposition of English Insects published in 1782, had arranged his Hymenoptera and Diptera according to characters derived from this same circumstance[1453]: Mr. Jones in the Linnean Transactions had made good use of it in dividing the Diurnal Lepidoptera into groups[1454]: and in the Monographia Apum AngliÆ, the characters exhibited by the various groups into which LinnÉ's genus Apis was resolvable, as to the neuration of their wings, were described[1455]. But M. Jurine was the first Entomologist who made that circumstance the keystone of a system; which indeed he restricted to Hymenopterous and Dipterous insects, but which might be extended much further. As this system has been before sufficiently enlarged upon[1456], I need here only mention it.

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To particularize the various entomological works in every department of the science, that have appeared since the commencement of the era of Fabricius, would require a volume. Such was its progress and spread, that in every corner of Europe the pens and pencils of able and eminent men, whose works have almost all been quoted in the course of our correspondence, have been employed to illustrate it[1457]. I may observe, however, that the Internal Anatomy of Insects, a branch of Entomology which on account of its difficulty, from the extreme nicety required in dissecting them, had before been cultivated by scarcely more than a single student in an age, has now attracted numerous votaries. In Germany—Carus, Gaede, Herold, Posselt, Ramdohr, Rifferschweils, Sprengel, and others, have distinguished themselves in this arena: and in France, besides the illustrious Baron Cuvier (himself a host), Marcel de Serres, Leon Dufour, and very recently, by his elaborate essays On the Flight of Insects and its wonderful apparatus, one of the most acute of anatomical physiologists, M. Chabrier,—have all contributed greatly to the elucidation of this interesting part of the science. In our own country very little has hitherto been effected in this line; but a learned Oxford Professor (Kidd) has presented to the Royal Society an account of the anatomy of the Mole-cricket, which entitles him to an eminent station amongst the above worthies.

I may likewise further observe, that the pictorial department of Entomology was, during the period I am speaking of, carried to its greatest perfection. Painters of insects formerly were satisfied with giving a representation generally correct, without attempting a faithful delineation of all the minor parts, particularly as to number;—for instance, the joints of the antennÆ and tarsi, the areolets of the wings, &c.: but now no one gives satisfaction as an entomological artist unless he is accurate in these respects.

I am, &c.

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