The analogies which the various objects of the animal kingdom mutually exhibit, have for the most part been either overlooked by modern Physiologists, or have been mistaken for characters that indicate affinity; a circumstance that has often perplexed or disrupted their systems. Dr. Virey appears to have been one of the first who obtained a general idea of the parallelism of animals in this respect[1282]; and M. Savigny has contrasted the Mandibulata and Haustellata of the insect tribes as presenting analogies to each other[1283]. But a countryman of our own (often mentioned with honour in the course of our correspondence), peculiarly gifted by nature, and qualified by education and his line of study for such speculations, and possessing moreover the invaluable opportunity of consulting at his ease one of the first Entomological cabinets in Europe, in a work that will for ever couple his name with the science that he cultivates[1284],—has first taught the Naturalist the respective value and real distinctions of the two kinds of relationship that I am now discussing. He has opened to the philosopher, the moralist and the divine, that hitherto closed door by which our first parents and their immediate descendants entered the temple of nature, and studied the symbols of knowledge that were there presented to them: and in addition to his labours (in numerous respects successful), in endeavouring to trace out the natural groups of beings connected by affinity, has pointed out how they illustrate each other by analogy; thus affording, as was before observed[1285], a most triumphant reply to the arguments of those modern sophists, who, from the graduated scale of affinities observable in creation, were endeavouring to prove that animals, in the lapse of ages, were in fact their own creators[1286].

For the more satisfactory elucidation of the subject before us, I shall consider, first, how we are to distinguish affinities from analogies; and then mention some of the various instances of the latter that occur between insects and other animals, and between different tribes of insects themselves.

To know what characters denote affinity and what are merely analogical, it must be kept in mind that the former being predicated of beings in a series (whether that series has its gyrations that return into themselves, or proceeds in a right line, or assumes any other intermediate direction, it matters not), it cannot be satisfactorily ascertained but by considering attentively the gradual approximation or recession of the structure to or from a certain type in any point of such series. If, therefore, you wish to ascertain whether the characters, in which any given object resembles other objects in certain groups, indicate affinity or only analogy, you must first make yourself acquainted with the common features which distinguish the animals known to belong to that group,—either those relating to their structure, or to their habits and economy. If the object under your eye partakes in these characters more or less, in proportion as it approaches the type or recedes from it, the relation it exhibits is that of affinity; but if, though it resembles some members of it in several points of its structure, it differs from the whole group in the general features and characteristic marks that distinguish it, the relation it bears to those members is merely that of analogy. Thus, for instance, Ascalaphus italicus in its antennæ, the colouring of its wings, and its general aspect, exhibits a striking resemblance to a butterfly; yet a closer examination of its characters will satisfy any one that it is in quite a different series, and has no affinity whatever to that genus. A departure, however, in only one respect from what may be called the normal characters of its group, does not annul the claim of any tribe of insects to remain in it; since this very often only indicates a retrocession from the type, and not a disruption of its ties of affinity. Thus the saw-flies (Serrifera) differ from the other Hymenoptera, though not in their pupæ, yet more or less in their larvæ; but this alone cannot countervail their agreement with that Order in their organs of manducation and motion, in their ovipositor, and in the other details of their structure[1287].

I have on a former occasion pointed out many of the analogies which take place between insects and other parts of the animal kingdom, and even between insects and the mineral and vegetable kingdoms[1288]: I shall now resume the subject more at large, but without recurring to those last mentioned. In considering the analogies which connect insects with other animals, or which they exhibit with respect to each other, we may have recourse to two methods. We may either consider them as placed somewhere between the two extremes of a convolving series, from which station we may trace these analogies upwards and downwards towards each limit; or we may conceive them and other animals in this respect arranged in a number of series that are parallel to each other, in which the opposite points are analogous. The first mode will perhaps best explain the analogies that exist between insects and other animals, and the last those between different groups of insects themselves. I shall give an example or two of each method, beginning with the first.

There are two tribes in the animal kingdom that seem placed in contrast to each other, both by their habits and by their structure. One of these is carnivorous, living by rapine and bloodshed, and can seldom be rendered subservient to our domestic purposes; while the other is herbivorous or granivorous, is quiet in its habits, and easily domesticated. Amongst insects we find the representatives of both: those of the first tribe are distinguished by their predaceous habits, by the open attacks, or by the various snares and artifices which they employ to entrap and destroy other insects. They may usually be known by their powerful jaws or instruments of suction; by their prominent or ferocious eyes; by the swiftness of their motions, either on the earth, in the air, or in the water; by their fraud and artifice in lying in wait for their prey. Amongst the Coleoptera, the Predaceous beetles,—including the Linnean genera Cicindela, Carabus[1289], Dytiscus, and Gyrinus,—are of this description; and they symbolize those higher animals that by open violence attack and devour their prey:—for instance, the sharks, pikes, &c., amongst the fishes; the eagles, hawks, &c., amongst the birds; and the whole feline genus amongst the beasts. Similar characters give a similar relation of analogy to the Mantidæ and Libellulina amongst the Orthoptera and Neuroptera. The whole family of Arachne, the larvæ of the Myrmeleonina, &c., portray those animals that to ferocity add cunning and stratagem, or suck the blood of their victims. The Myriapods symbolize in a striking manner the Ophidian reptiles. Look at an Iulus, and both in its motions and form you will acknowledge that it represents a living serpent; next turn your eyes to a centipede or Scolopendra, and you will find it nearly an exact model of the skeleton of a dead one, the flat segments of its body resembling the vertebræ, its curving legs the ribs, and its venomous maxillæ the poison-fangs. The great body of the Orthoptera, the Homopterous Hemiptera, the Lepidoptera, and Trichoptera, afford no example of Predaceous insects. All the analogies I have here particularized, ascending from the insect, terminate in races of a corresponding character and aspect amongst the Mammalia, and thus lead us towards man himself, or rather to men in whose minds those bad and malignant qualities prevail, which, when accompanied by power, harass and lay waste mankind; and thus ascending from symbol to symbol, we arrive at an animal who in his own person unites both matter and spirit, and is thus the member both of a visible and invisible world: and we are further instructed by these symbols,—perpetually recurring under different forms,—in the existence of evil and malignant spirits, whose object and delight is the corporeal and spiritual ruin of the noble creature who is placed at the head of the visible works of God.

The other tribe of animals that I mentioned of a milder character, may be looked upon as represented by many herbivorous, or not carnivorous, insects; amongst others, the Lamellicorn beetles imitate them by their remarkable horns, so that they wear the aspect of miniature bulls, or deer, or antelopes[1290], or rams, or goats, whether these horns are processes of the head or of the upper jaws. The gregarious Hymenoptera, some of which form part of our domestic treasures, may be regarded in some degree as belonging to this department. From insects the ascent upwards, with regard to form, is by some of the branchiostegous fishes, which symbolize the horns of cattle; with regard to character, by the various species of Cyprinus and other similar genera.—Whether any of the reptiles may be looked upon as falling into this division, I am not sufficiently conversant with them to assert; but if any, the Chelonians, or tortoise and turtle tribes, are entitled to that distinction. Amongst the birds, the Gallinæ and Anseres,—from which Orders we derive our domestic poultry, whether terrestrial or aquatic,—and our game, form the step next below the ruminants, or cattle: and we are thus again led towards man, and are symbolically instructed in those domestic and social qualities which endear us to each other, best promote the general welfare, and render us most like good spirits and the Divinity himself; of whom the perpetual recurrence of animals exhibiting these amiable and useful qualities is calculated to impress upon us some notion. I might mention many more instances of ascending analogies; as from some of the Diptera by the parrots, to the Quadrumanes or monkey tribes—or from some of the Iulidæ that roll themselves into a ball, to the Armadillo; but these are sufficient to set your mind at work upon the subject, so that you may trace them for yourself. Nor shall I occupy your time by pointing out how analogies may be traced from insects downwards towards the lowest term in the scale of animal life, but proceed to consider the analogies observable between insects themselves; in which I shall follow the second method lately mentioned, and consider them as arranged in parallel series.

In studying the analogies that take place between insects themselves, we should always bear in mind that our inquiry is not concerning an affinity which demands a correspondence in various particulars that are not necessary to constitute an analogy; as, for instance, that there should be a mutual imitation in all the states of any two insects. Wherever we discover a marked resemblance between two perfect insects, there is a true analogy, though their metamorphosis may differ; and where there is not that resemblance, though the metamorphosis may agree, there is no analogy. In fact, insects are sometimes analogous in their first state and not in their last; and at other times analogous in their last and not in their first; but the analogy is most perfect when it holds in all their states: it then, indeed, almost approaches to an affinity. They may also be analogous to each other in their habits and economy, when there is little or no resemblance in their form; and, vice versa, be analogous in their form and not in their habits. So that different sets of analogies may be assumed as foundations for different systems. Thus Mr. MacLeay assumes the metamorphosis as the basis of analogy between the corresponding Orders of Mandibulata and Haustellata[1291], while M. Savigny compares the perfect insects[1292]: the result therefore differs in some instances. I shall now lay before you in a tabular view their plans and my own.

Savigny.

Mandibulata. Haustellata.
Neuroptera ... Lepidoptera
Ascalaphus Papilio
Hymenoptera ... Diptera
Eucera Tabanus
Orthoptera ... Homoptera
Locusta L. Cicada
Aptera ... Aphaniptera
Nirmus Pulex.