animals, goading the latter sometimes almost to madness by their severe and incessant punctures. The winged horse-ticks (Hippobosca), the bird-flies (Ornithomyia), the wingless sheep-ticks (Melophagi), and the spider-flies (Nycteribia), and bee-lice (Braula), which are also destitute of wings, are truly parasitical in their habits, and pass their whole lives upon the skin of animals. Bot-flies, or gad-flies (Estrida), as they are sometimes called, appear to take no food while in the winged state, and are destitute of a proboscis; the nourishment obtained by their larvæ, which, as is well known, live in the bodies of horses, cattle, sheep, and other animals, being sufficient to last these insects during the rest of their lives. Some flies, though apparently harmless in the winged state, deposit their eggs on plants, on the juices of which their young subsist, and are oftentimes productive of immense injury to vegetation; among these the most notorious for their depredations are the gall-gnats (Cecidomyia), including the wheat-fly and Hessian fly, the root-eating maggots of some of the long-legged gnats (Tipulæ), those of the flowerflies (Anthomyia), and the two-winged gall-flies and fruit-flies (Ortalides). To this list of noxious flies are to be added the common house. flies (Musca), which pass through the maggot state in dung and other filth, the blue-bottle or blow-flies, and meat-flies (Lucilia and Calliphora), together with the maggot-producing or viviparous flesh-flies (Sarcophage and Cynomyia), whose maggots live in flesh, the cheesefly (Piophila), the parent of the well-known skippers, and a few others that in the larva state attack our household stores. Some flies are entirely harmless in all their states, and many are eminently useful in various ways. Even the common house-flies, and flesh-flies, together with others, for which no names exist in our language, render important services by feeding while larvæ upon dung, carrion, and all kinds of filth, by which means, and by similar services, rendered by various tribes of scavenger-beetles, these offensive matters speedily disappear, instead of remaining to decay slowly, thereby tainting the air and rendering it unwholesome. Those whose larvæ live in stagnant water, such as gnats (Culicida), feather-horned gnats (Chironomus, &c.), the soldier-flies (Stratiomyade), the rat-tailed flies (Helophilus, &c. &c.), tend to prevent the water from becoming putrid, by devouring the decayed animal and vegetable matter it contains. The maggots of some flies (Mycetophila and various Muscade) live in mushrooms, toadstools, and similar excrescences growing on trees; those of others (Sargi, Xylophagidæ, Asilida, Thereva, Milesiæ, Xylotæ, Borbori, &c. &c.), in rotten wood and bark, thereby joining with the grubs of certain beetles to hasten the

removal of these dead and useless substances, and make room for new and more vigorous vegetation. Some of these wood-eating insects, with others, when transformed to flies (Asilidæ, Rhagionida, Dolichopida, and Xylophagida), prey on other insects. Some (Syrphida), though not predaceous themselves in the winged state, deposit their eggs among plant-lice, upon the blood of which their young afterwards subsist. Many (Conopida, excluding Stomoxys, Tachina, Ocypteræ, Phoræ, &c.) lay their eggs on caterpillars, and on various other larvæ, within the bodies of which the maggots hatched from these eggs live till they destroy their victims. And finally others (Anthracida and Volucella) drop their eggs in the nests of insects, whose offspring are starved to death, by being robbed of their food by the offspring of these cuckooflies. Besides performing their various appointed tasks in the economy of nature, flies, and other insects, subserve another highly important purpose, for which an all-wise Providence has designed them, namely, that of furnishing food to numerous other animals. Not to mention the various kinds of insect-eating quadrupeds, such as bats, moles, and the like, many birds live partly or entirely on insects. The finest songbirds, nightingales and thrushes, feast with the highest relish on maggots of all kinds, as well as on flies and other insects, while the warblers, vireous, and especially the fly-catchers and swallows, devour these twowinged insects in great numbers.

The seven foregoing orders constitute very natural groups, relatively of nearly equal importance, and sufficiently distinct from each other, but connected at different points by various resemblances. It is impossible to show the mutual relations of these orders, when they are arranged in a continuous series, but these can be better expressed and understood by grouping the orders together in a cluster, so that each order shall come in contact with several others.

Besides these seven orders, there are several smaller groups, which some naturalists have thought proper to raise to the rank of independent orders. Upon the principal of these, a few remarks will now be made.

The little order STREPSIPTERA of Kirby, or RHIPIPTERA of Latreille, consists of certain minute insects, which undergo their transformations within the bodies of bees and wasps. One of them, the Xenos Peckii, was discovered by Professor Peck in the common brown wasp (Polistes fuscata) of this

country. The larva is maggot-like, and lives between the rings of the back of the wasp; the pupa resembles that of some flies, and is cased in the dried skin of the larva. The females never acquire wings, and never leave the bodies of the bees or wasps into which they penetrate while young. The males, in the adult state, have a pair of short, narrow, and twisted members, instead of fore-wings, and two very large hind-wings, folded lengthwise like a fan. The mouth is provided with a pair of slender, sharp-pointed jaws, better adapted for piercing than for biting. It is very difficult to determine the proper place of these insects in a natural arrangement. Latreille put them between the Lepidoptera and Diptera, but thinks them most nearly allied to some of the Hymenoptera.

The flea tribe (Pulicida) was placed among the bugs, or Hemiptera, by Fabricius. It constitutes the order APTERA of Leach, SIPHONAPTERA of Latreille, and APHANIPTERA of Kirby. Fleas are destitute of wings, in the place whereof there are four little scales, pressed closely to the sides of their bodies; their mouth is fitted for suction, and provided with several lancet-like pieces for making punctures; they undergo a complete transformation; their larvæ are worm-like and without feet; and their pupa have the legs free. These insects, of which there are many different kinds, are intermediate in their characteristics between the Hemiptera and the Diptera, and seem to connect more closely these two orders together.

The ear-wigs (Forficulada), of which also there are many kinds, were placed by Linnæus in the order Coleoptera, but most naturalists now include them among the Orthoptera ; indeed, they seem to be related to both orders, but most closely to the Orthoptera, with which they agree in their partial transformations, and active pupa. They form the little order DERMAPTERA of Leach, or EUPLEXOPTERA of Westwood.

The spider-flies, bird-flies, sheep-tick, &c. (Hippoboscada), which, with Latreille and others, I have retained among the Diptera, form the order HoMALOPTERA of Leach, and the English entomologists.

The May-flies, or case-flies (Phryganeada), have been separated from the Neuroptera; and constitute the order TRICHO

PTERA of Kirby. Latreille and most of the naturalists of the continent of Europe still retain them in Neuroptera, to which they seem properly to belong.

The Thrips tribe consists of minute insects more closely allied to Hemiptera than to any other order, but resembling, in some respects, the Orthoptera also. It forms the little order THYSANOPTERA of Haliday; but I propose to leave it, as Latreille has done, among the Hemiptera.

The English entomologists separate from Hemiptera the cicadas or harvest-flies, lantern-flies, frog-hoppers, plant-lice, bark-lice, &c., under the name of HOMOPTERA; but these insects seem too nearly to resemble the true Hemiptera to warrant the separation.

Burmeister, a Prussian naturalist, has subdivided the Neuroptera into the orders NEUROPTERA and DICTYOTOPTERA, the latter to include the species which undergo only a partial transformation. If Hemiptera is to be subdivided, as above mentioned, then this division of Neuroptera will be justifiable also.

Objections have often been raised against the study of natural history, and many persons have been discouraged from attempting it, on account of the formidable array of scientific names and terms which it presents to the beginner; and some men of mean and contracted minds have made themselves merry at the expense of naturalists, and have sought to bring the writings of the latter into contempt, because of the scientific language and names they were obliged to employ. Entomology, or the science that treats of insects, abounds in such names more than any other branch of natural history; for the different kinds of insects very far outnumber the species in every class of the animal, vegetable, and mineral kingdoms. It is owing to this excessive number of species, and to the small size and unobtrusive character of many insects, that comparatively very few have received any common names, either in our own, or in other modern tongues; and hence most of those that have been described in works of natural history, are known only by their scientific names. The latter have the advantage over other names in being intelligible to

all well-educated persons in all parts of the world; while the common names of animals and plants in our own and other modern languages are very limited in their application, and moreover are often misapplied. For example, the name weevil is given, in this country, to at least six different kinds of insects, two of which are moths, two are flies, and two are beetles. Moreover, since nearly four thousand species of weevils have actually been scientifically named and described, when mention is made of "the weevil," it may well be a subject of doubt to which of these four thousand species the speaker or writer intends to refer; whereas, if the scientific name of the species in question were made known, this doubt would at once be removed. To give to each of these weevils a short, appropriate, significant, and purely English name, would be very difficult, if not impossible, and there would be great danger of overburdening the memory with such a number of names; but, by means of the ingenious and simple method of nomenclature invented by Linnæus, these weevils are all arranged under three hundred and fifty-five generical, or surnames, requiring in addition only a small number of different words, like christian names, to indicate the various species or kinds. There is oftentimes a great convenience in the use of single collective terms for groups of animals and plants, whereby the necessity for enumerating all the individual contents or the characteristics of these groups is avoided. Thus the single word Ruminantia stands for camels, lamas, giraffes, deer, antelopes, goats, sheep, and kine, or for all the hoofed quadrupeds, which ruminate or chew the cud, and have no front teeth in the upper jaw; Lepidoptera includes all the various kinds of butterflies, hawk-moths, and millers or moths, or insects having wings covered with branny scales, and a spiral tongue instead of jaws, and whose young appear in the form of caterpillars. It would be difficult to find or invent any single English words which would be at once so convenient and so expressive. This, therefore, is an additional reason why scientific names ought to be preferred to all others, at least in works of natural history, where it is highly important that the objects described should have names that are short, significant in themselves,