 
There is no human science which to a rational mind exhibits a greater variety of attractions, or which is more deserving of general esteem, than that of NATURAL HISTORY; accordingly we find, that from the earliest times in which the sciences have been promulgated, it has never been entirely destitute of its votaries; but, on the contrary, has for ages employed the lives of many learned men, as being, in fact, the study of DIVINE WISDOM displayed in the creation: the farther our researches are carried, the more striking proofs of it every where abound. In the present century, an Æra particularly devoted to investigation, and propitious to discovery and improvement in various branches of science, Natural History, so far from being neglected, has been more generally cultivated, and pursued with an ardor unprecedented at any former period. Men of the first rank in literature have become indefatigable labourers in the vast and unbounded field which it presents to the eyes of an accurate and attentive observer. The animal, the vegetable, and the mineral kingdoms, have been examined with the utmost care; that confusion and perplexity which seemed unavoidably to result from a view of the immense variety of articles contained in each of those departments, Of the abundance of articles enumerated in books of Natural History, there are comparatively few, whose uses are as yet known, or their properties fully understood. The true naturalist should always bear in mind that there is a vast difference between retaining the names, and investigating the nature and peculiar qualities of the creatures to which they belong. It is highly proper, indeed necessary, that the multifarious objects of Natural History should be well ascertained and distinguished with nicety in all their varieties; the science and admirers of it are, therefore, unquestionably indebted to the able naturalists who have devoted their time, and exercised their ingenuity in devising commodious methods of arrangement, and invented systems for identifying the several subjects with accuracy, and less danger of fallacy or mistake: but all who are, or would wish to be thought naturalists, ought to consider, that the best possible mode of classification is, after all, but an introduction to Natural History. The ingenious and indefatigable LinnÆus, who spent his life in fabricating the curious system now generally adopted, intended it certainly for the improvement of the science, as a basis for the service of knowledge The study of nature, or in other words, a serious contemplation of the works of GOD, is indeed a great and proper object for the exercise of our rational faculties; nor can we perhaps employ them better, than in endeavouring to make ourselves acquainted with the works of that glorious Being from whom they were received. Though there is a great deal of pleasure in contemplating the material world, or that system of bodies into which the DIVINE ARCHITECT has so admirably wrought the mass of dead matter, with the several relations which those bodies bear to one another; there is still something more wonderful and surprizing arising from the contemplation of the animated world; by which is to be understood all those animals with which every part of the universe is furnished. The material world is only the shell of the universe; the animated world are its inhabitants. Existence is a blessing to those beings only which are endowed with perception, and appears useless when bestowed upon dead matter, any farther than as it is subservient to beings which are conscious of their existence. Thus we find, from the bodies which lie under our observation, that matter is only made as the basis and support of animals, and that there is no more of the one than what is necessary for the exigence of the other. There are some living creatures which are raised but just above dead matter; there are many others, but one remove from these, which have no other senses but those of feeling and taste; others have still an additional sense of hearing; others of smell, and again others of sight. It is wonderful to observe, by what a gradual progress life advances through a prodigious variety of species, before a creature is formed that possesses all these senses; and even among these, there is such a different degree of perfection in the senses which one animal enjoys beyond what appears in another, that, though the sense in different animals be distinguished by the same common denomination, it seems almost of a different nature. If, after this, we look into the several inward qualities of sagacity, or what is generally called instinct, we find them rising after the same manner imperceptibly one above another, and receiving additional improvements, according to the species in which they are implanted. This progress in nature is so very gradual, that what appears to us the most perfect of an inferior species, comes very near to the most imperfect, as we are accustomed to call it, of that which is immediately above it. The exuberant and overflowing goodness of the SUPREME BEING, whose mercy extends to all his works, is plainly seen, as before observed, from his having made so very little matter, at least what falls within our knowledge, that does not swarm with life; nor is his goodness less visible in the diversity than in the multitude of living creatures. Had he only made one species of animals, none else could have enjoyed the happiness of existence; he has, therefore, included in his creation, every degree of life, every capacity of being. The whole chasm of nature, from a plant to a man, is filled up with diverse kinds of creatures, rising one above another, by such a gentle and easy ascent, that the little transitions and deviations from one species to the other are almost insensible. This intermediate space is so prudently managed, In this system of creation there is no creature so wonderful in its nature, and which so much merits our particular attention, as man, who fills up the middle space between the animal and intellectual nature, the visible and invisible world; and is that link, in the chain of beings, which has been often termed the “nexus utriusque mundi.” So that he, who in one respect being associated with angels and arch-angels, may look upon a BEING of infinite perfection as his father, and the highest order of spirits as his brethren, may, in another respect, say to corruption, “Thou art my father, and to the worm, thou art my mother and my sister.”[46] [46] Spectator, Vol. vii. Numb. 519. There are, however, many who form their judgments of the works of nature from external appearance only; hence they imagine, that the greatest and most magnificent are the only perfect parts of creation, and worthy of our regard. Hence they confine their attention to the more splendid and shining branches of philosophy, and are too apt to treat the other parts with coolness and indifference, not to say contempt. But surely a true philosopher is one who diligently pursues the study of nature in all its branches; who can behold with admiration her noblest productions, yet view with pleasure the smallest of her works: in short, one who thinks every thing excellent that owes its formation to the GOD of nature; and we need only take a transient view of the smaller creatures with which the If we examine insects with attention, we shall soon be convinced of their divine origin, and survey with admiration the wonderful art and mechanism of their structure, wherein such a number of vessels, parts, and movements are collected in a single point; yet are they furnished with weapons to seize their prey, dexterity to escape their foes, every thing requisite to perform the business of their stations, and enjoy the pleasures of their conditions. What a profusion of the richest ornaments and the gayest colours are often bestowed on one little insect! and yet there are thousands of others that are as beautiful and wonderful in their kind; some are covered with shining coats of mail, others are adorned with plumes of feathers, all of them furnished with every thing that is proper to make them answer the purposes for which they were designed. “After an attentive examination of the nature and fabric of both the least and largest animals, I cannot,” says the great and excellent Swammerdam, “but allow the less an equal, perhaps a superior degree of dignity; whoever duly considers the conduct and instinct of the one, with the manners and actions of the other, must acknowledge, that they are all under the direction and controul of a supreme and particular intelligence; which, as in the largest it extends beyond the limits of our comprehension, escapes our researches in the smallest. If, while we dissect with care the larger animals, we are filled with wonder at the elegant disposition of their limbs, the inimitable order of their muscles, The subserviency of the several beings in the visible creation to one another; the order in which each of them appears in that appointed season, when only it can be conducive to the purposes of the rest; and the preservation of a sufficient number of every species, amidst the immense havoc that reigns throughout, are, among other things, proofs of the amazing and incomprehensible wisdom by which they were all formed. With what pleasure does the mind, accustomed to look up from effects to their causes, from created beings to the GREAT SOURCE OF BEING, view that unbounded beneficence, which leaves not the smallest space, capable of supporting existence of any kind, unplanted with them. There is hardly any portion of matter, or the least drop of fluid naturally found on the surface of the earth, that is not inhabited by multitudes of animals; the subterraneous regions are peopled with their minute inhabitants, and the abyss of the sea, where no human eye can penetrate, abounds with animated beings. The air is usually considered as the great source of destruction to bodies, whether animal or vegetable; but we do not always understand by what means or in what manner it is performed. What we term destruction and decay of one substance, occasions The same wisdom which placed the sun in the center of the system, and arranged the several planets around him in their order, has no less shewn itself in the provision made for the food and dwelling of every bird that roams in the air, and every beast that wanders in the desert; equally great in the smallest and in the most magnificent objects; in the star and in the insect; in the elephant and in the fly; in the beam that shines from heaven and in the grass that cloathes the ground. Nothing is overlooked, nothing is carelessly performed: every thing that exists is adapted with perfect symmetry to the end for which it was designed. This wisdom displayed by the Almighty in the creation, was not intended merely to gratify curiosity and to raise wonder; it ought to beget profound submission, and pious trust in every heart. Histories of the providence and caution, the care and foresight of the most inconsiderable among animal beings, must surely ever be read with pleasure and attention, as conveying a most beautiful lesson to a reflecting mind; it is impossible for any one thus instructed to think that the Great Being, who has been so careful of those inferior creatures, can be regardless of him whom he has placed in a station infinitely more exalted. Throughout the whole system of things, we behold a manifest tendency to promote the benefit either of the rational or the animal creation. In some parts of nature, this tendency may be less obvious than in others. Objects, which to us seem useless or hurtful, may sometimes occur; and strange it were, if in so vast and complicated a system, difficulties of this kind should not occasionally present themselves to beings, whose views are so narrow and limited as ours. It is well known, that in proportion as the knowledge of nature has increased among men, these difficulties have diminished. Satisfactory accounts have been given of many perplexing appearances; useful and proper purposes have been found to be promoted by objects which were at first thought to be unprofitable or noxious.[47] [47] The great beauty of the dye produced by the cochineal insect, and the medical virtues of the cantharis, have occasioned them to be considered as very extensive and valuable articles of commerce. The benefits derived from the bee and the silk-worm are universally known; and spiders, could a method be devised to induce them to live in harmony, might also be productive of very essential advantages to the human race. Edit. Malignant must be the mind of that person; with a distorted eye he must have contemplated creation, who can suspect that it is not the production of infinite benignity and goodness. How many clear marks of benevolent intention appear every where around us? What a profusion of beauty and ornament is poured forth on the face of nature? What a magnificent spectacle presented to the view of man? What a supply contrived for his [48] Blair’s Sermons. Let us not then slight, or deem that unworthy our notice, in which immensity is so conspicuous; or that trivial, in which there is such a manifestation of infinite beneficence; but rather let those striking displays of creating goodness call forth, on our part, responsive love, gratitude, and veneration. To this Great Father of all existence and life, to Him who hath raised us up to behold the light of day, and to enjoy all the comforts which his world presents, let our hearts send forth a perpetual hymn of praise. Evening and morning let us celebrate Him who maketh the morning and the evening to rejoice over our heads; who “openeth his hand and satisfieth the desire of every living thing.” Let us rejoice that we are brought into a world, which is the production of infinite goodness; over which a supreme intelligence presides; and where nothing happens but by his divine Such, in general, are the effects which meditation on the works of the creation ought to produce. It presents such an astonishing conjunction of power, wisdom, and goodness, as we cannot behold without religious veneration. In short, the world around us is the mighty volume wherein god hath declared himself; a picture wherein his perfections are displayed. The book of nature is written in a character that every one may read; it consists not of words, but things; it is a school where GOD is the teacher. All the objects of sense are as the letters of an universal language, in which all people and nations have a common interest; the Creator himself has made this use of it, revealing his will by it, and referring man to it for instruction. Hence the universal agreement between nature and revelation; hence, also, he that can understand GOD as the Fountain of truth and the Saviour of men in the holy scriptures, will be better enabled to understand and adore him as the fountain of power and goodness in the natural creation. Thus will philosophy and divinity go hand in hand, and shew that the world was made, as the scriptures were written, for our instruction; and that the creation of GOD is a school for Christians, if they use it aright.[49] [49] It is a curious, though melancholy subject of contemplation, to observe how different have been the sentiments of learned and reputedly pious men in times less enlightened; a period when attention to, or compassion for, the animal creation could find no place in a breast that withheld and denied the mercy of God unto men; when mercy itself was deemed heresy! Even in prior and purer times it was affirmed that “It is absurd, and a disparagement to the majesty of GOD to suppose him to know how many insects there are in the world, or how many fishes in the sea; yea, that such an idea of the Omniscience of GOD would be foolish flattery to Him, and an injury to ourselves.” For the satisfaction of the learned reader, I shall here quote the original. “Absurdum est ad hoc Dei deducere Majestatem, ut sciat per momenta singula quot nascantur culices, quotve moriantur; quÆ cimicum et pulicum et muscarum sit in terra multitudo; quanti pisces in aqua natent, et qui de minoribus majorum prÆdÆ cedere debeant. Non simus tam fatui Adulatores Dei, ut dum potentiam ejus ad ima detrahimus in nos ipsos injuriosi simus.” Hieronymi Comment. in Abac. Lib. 1. Edit. Basil. Tom. vi. p. 187. Edit. A GENERAL DESCRIPTION OF INSECTS.The subjects of that part of the creation we are now going to survey, merit our attention as exceeding the rest of animated nature in their numbers, the singularity of their appearance, and the variety of their forms. Earth, air, and water are filled with hosts of them. Being for the major part very small, and myriads so diminutive, as even to be imperceptible to the unassisted eye, our knowledge of them, and their component parts would be extremely circumscribed and imperfect, were it not for the advantages derived from the use of the microscope; but happily possessed of this valuable instrument, an inexhaustible source of entertainment and instruction is afforded to the curious inquirer into the wonders of nature. The beauties of the minuter parts of creation are not more hidden from our unassisted sight, than the ends and purposes of their oeconomy from slight and superficial observation; the microscope does not more amaze and charm as with a discovery of the first, than the application of our faculties in investigating the latter. The name of INSECT has been appropriated to these small animals on account of the sections or divisions that are observable in the bodies of the greatest part of them; though, perhaps, it is An insect is now generally defined to be, an animated being whose head is furnished with antennÆ; that is destitute of bones, but which, instead thereof, is covered with a very hard skin; that has six or more feet; and that breathes through spiracula, or pores placed in the side of the body. To be more particular, quadrupeds, birds, and fishes have an internal skeleton of bones, to which the muscles are affixed; but the whole interior body of insects is composed of soft flesh, and the muscles are attached to an external skeleton, serving the double purpose of skin and bone. Insects are by most writers considered as divided into four principal parts: the caput, or head; the thorax, or trunk; the abdomen, or belly; and artus, or limbs. A perfect knowledge of these parts, and their several subdivisions, is requisite for those who are desirous of forming accurate ideas of these minute animals, or who wish to arrange them in their proper classes. The head is affixed to the thorax by a species of articulation or joint; it is the principal seat of the senses, and contains the rudiments of the brain;[50] it is furnished with a mouth, eyes, antennÆ, a forehead, a throat, and stemmata. In the greater part of insects the head is distinctly divided from the thorax, but in others it coalesces with it. The head of some insects is very large compared with the size of their bodies; the proportion between the head of the same insect is not always similar; in the [50] Fabricius Philos. Entomolog. p. 18. Os, the mouth, is a part of the insect to which the naturalist will find it necessary to pay a very particular attention; Fabricius goes so far as to assert that, without a thorough knowledge of the mouth, its form, and various appendages, it will be impossible ever to discriminate with accuracy one insect from another. In the structure of the mouth considerable art and wisdom is displayed; the diversity of the figure is almost as great as the variety of species. It is usually placed in the forepart of the head, extending somewhat downwards; in the chermes, coccus, and some other insects, it is placed under the breast. In some insects, the mouth is forcipated, to catch, hold, and tear the prey; in others, aculeated, to pierce and wound animals, and suck their blood; in others, strongly ridged with jaws and teeth, to gnaw and scrape out their food, carry burdens, perforate the earth, nay the hardest wood, and even stones themselves, for habitations and nests for their young. Others are furnished with a kind of tube MaxillÆ, the jaws, are generally two in number; in some, four; in others, more. They are sometimes placed in an horizontal, sometimes in a transverse direction; the inner edge is serrated, or furnished with small teeth, as in the cicada, nepa, notonecta, cimex, (bug,) aphis, and remarkably so in some curculeones. The rostrum, or proboscis, is in general a very curious and complicated organ; it is the mouth drawn out to a rigid point. In many insects of the hemiptera class, it is bent down towards the breast and belly. It has by some writers been considered as serving at once the different purposes of mouth, nose, and windpipe, enabling the insect to extract the juices of plants, communicate the sensation of smelling, and convey air to the body. Lingua, the tongue, is a taper and compact instrument, by which the insect obtains the juices of plants. Some can contract or expand it, others roll it up with dexterity; in some it is inclosed within a sheath. It is taper and spiral in the butterfly, tubular and fleshy in the fly; in all affording agreeable amusement for the microscope. To exemplify which in one or two instances, while it relieves the reader from the tediousness of narration, will, it is hoped, animate him to farther researches on the subject. OF THE PROBOSCIS OF THE BEE.Every day’s experience shews that the more we penetrate into the hidden recesses and internal parts of natural bodies, the more From what has here been said, it will be easy to perceive, that the limits of these Essays will not permit our entering largely into a description of the minute parts of the proboscis of the bee; for an ample account of which recourse must be had to the works of Swammerdam and Reaumur. The last writer, like a skilful workman who takes to pieces a watch which he himself has made, exhibits to you the several parts of which it is composed, and explains their fitness, their adjustments, their uses, the play of the pivots, springs, and pillars; for all these parts, and many more, are to be found in the proboscis of a bee. It is by this small instrument that the bee procures the food necessary for its subsistence. In a general view, it may be considered as consisting of seven pieces; one of these, i i, b c, Fig. 3. Plate XIII. is placed in the middle; this is supposed to be pervious, and to constitute what may be properly called the tongue; the other six smaller parts or sheaths, disposed in three pairs, are placed on each side of the former: they not only assist in extracting and gathering the honey from the flowers, but they also protect and strengthen the part. The proboscis itself is very curiously divided; the divisions are elegant and regular, and are beset all round with shaggy triangular fibres or villi, distributed in beautiful order: these divisions, though very numerous, appear [51] Philos. Trans. for 1792, Part I. The two pieces a a of the exterior sheath are of a substance partly between bone and horn, and partly membranaceous; they are set round with fibres, and are furnished with air vessels, which are distributed through their whole texture; the upper ends f f of this sheath appear to be a little bent, but can be straitened by the bee when they are applied to the proboscis. At d d are two articulations, by means of which the pieces a a may be occasionally bent. The joints contribute towards bending the proboscis downwards, or rather underneath, against the head. These sheaths, together with two interior ones e e, assist in defending, covering, and protecting it from injuries; it is also probable that they promote the descent of the honey, by pressing the proboscis. The parts k k of this sheath have been called by some writers the root. The two parts e e of the interior sheath are placed higher than those of the exterior one; they originate at g g on the proboscis itself, and near that part or articulation, by which the bee can upon occasion bend the proboscis; this sheath, therefore, always moves with the middle part i i, and is carried forward by it, the exterior sheath being left behind, because its attachments and origin are below that of the proboscis. The pieces e e are very similar in structure to those of a a, only that each of them has on the upper part three joints, the lower one is much longer than the other two; they are all of them surrounded with short fibres. The proboscis is partly membranaceous, and partly of a gristly nature; the lower part is formed in such a manner, that it will swell out considerably, by which means the internal cavity may be prodigiously enlarged, and rendered capable of receiving a very large quantity of native and undigested honey, and larger than might be expected from its size. When the proboscis is shut up and inactive, it is very much flattened, and is three or four times broader than it is thick. The edges are always round; it grows tapering, though very gradually, towards the extremity. The lower and membranaceous part of the trunk has no fibres or villi on it, but is covered with little protuberant transparent pimples, that are placed in regular order, and at equal distances from each other, resembling the little risings observable on the skin of birds when the feathers have been plucked off. They are probably glandules, and may have a considerable share in changing or preparing the honey that is swallowed or taken up by the proboscis. Down the middle of the proboscis there is a tube of a much harder nature than the sides, it grows gradually smaller towards the top; at this place the tongue itself is extremely villous, having some very long villi at the point; whether they are open The proboscis terminates in a small cylinder c, at the top of which there is a little globule or nipple; the bee can contract this cylindrical part, and the little membrane in which the villi are fixed, into a much smaller compass, and draw it inwards. The exterior sheaths lap over each other on the upper part, so that the outside of the proboscis is protected by a very strong double case, a covering that was unnecessary for the under part; because when this instrument is in use the sheaths are opened, but when it is inactive, it is so folded that the under part is protected by the body of the bee. Withinside the exterior sheath, and near the bottom q, are two levers, which are fixed to the end of the proboscis, and by which it is raised and lowered. Swammerdam thinks that the honey is, as it were, pumped or sucked up by the bee through the hole at the end b of the tongue; he does not seem to have discovered the apertures which are on the cylindrical part, near the end b. But Reaumur is of opinion that it is used to lap up the fluid, which is then conveyed down between the sheath to the mouth of the bee. To ascertain this, he placed a bee in a glass tube, the inside of which was rubbed over with honey, and little pieces thereof placed in different parts; the bee placed the tongue on the honey; stretching the end beyond the piece thereof, she bent it into the form of a bow, and inserted the most convex part of the bow into the honey; by rubbing the glass backwards and forwards with this part, she soon cleaned that portion to which it was applied, conveying the honey afterwards to the throat by the vermicular motion of the tongue. If you attentively observe a bee, when it has placed itself on a full-blown flower, the activity and address with which it uses this apparatus will be very conspicuous. It lengthens the end, and applies it to the bottom of the petals or leaves of the flower, moving it continually in a vast variety of different directions; lengthening and shortening, bending and turning it in every possible way, to adapt it to the form, &c. of the leaves of the flower. These various movements are executed with a promptitude that surpasses all description. The whole of this curious apparatus can be folded up into a very small compass under the head and neck. The larynx, or that part next to the head, falls back into the neck, which brings the extreme end of the first portion of the proboscis within the upper lip, or behind the two teeth; then the whole of the second part is bent down upon and under the first part, and the two last sheaths or scales are also bent down over the whole; so that the true tongue is inclosed laterally by the two second horny sheaths, and over the whole lie the two first. OF THE PROBOSCIS OF THE BUTTERFLY.From the tongue of the bee, let us now direct our attention to that of the butterfly. This is a spiral substance, somewhat resembling the spring of a watch when wound up, consisting of eight rounds; by means of a pin you may gently pull it out to its full length; it grows gradually tapering from the base, at the end it divides or separates into two tubes, each furnished with little organs of suction; probably, it is by these that it extracts the juices on which it feeds, and not by the extreme ends of the tongue. As the butterfly has no mouth, the proboscis is the only alimentary organ; when separated from the insect, it will often OF THE PROBOSCIS OF THE CULEX OR GNAT.The proboscis of the gnat consists of a great number of extremely delicate pieces, all concurring to one purpose; this is the instrument with which it strikes the flesh, and sucks the blood of animal bodies. The only part exhibited to the naked eye is the sheath, which contains all the other pieces. This sheath is a cylindrical tube, which is slit in such a manner, that the insect can separate it from the dart, and bend it more or less in proportion as the dart is plunged into the wound. From this tube the sting is darted, which consists of five or six blades or lancets of exquisite minuteness, lying one over the other; some of these are sharpened like a two-edged sword, while others are dentated and barbed at their extremities like the head of an arrow. The instant the gnat lances this bundle of darts into the flesh, and penetrates a vein, a drop or two of fluid is by it insinuated into the wound, by which the blood is attenuated, and the blades acting as so many capillary tubes, the blood ascends in them, and is conveyed into the body of the gnat. The injected fluid also by its fermentation causes that disagreeable and teazing sensation of itching, to which most persons are subjected, after having sustained an attack from one or more of these little animals.[52] [52] To some persons the gnat (culex pipiens) is so truly formidable, that, during the Summer season, they constantly dread the approach of evening, that being the time when these blood-thirsty marauders sally forth in great numbers, pursue them wherever they go, and exempt no part of the face, hands, or even the legs from their depredations; the consequences of which are, violent, though happily only local and temporary inflammation, attended with insupportable itching, succeeded by tumors very similar to those occasioned by a scald; when these have discharged the pellucid fluid they contain, the symptoms subside. Instances have been known in the vicinity of London, where for several days the eyes of the sufferers have been closed, the nose and lips violently swelled, the fingers of both hands so affected as to prevent their motion, and the legs equally affected. It is remarkable, that in general those who thus suffer are not conscious of the moment when they receive the injury, but are soon made sensible of it by the effect it produces. The approach of the enemy is, however, always known by the singing or humming noise they make; the peculiar note of which, though rendered very familiar by daily repetition, is never esteemed sufficiently musical to render it pleasant or agreeable to the destined victims. Amongst the variety of remedies which have been recommended for the cure of this temporary evil, Barbut mentions the immediate application of volatile alkali, or scratching the part newly stung, and washing it with cold water; he likewise asserts, that rubbing the part at night with fuller’s earth and water abates the inflammation. As preventives are certainly more acceptable than curatives, I wish I were enabled to recommend such in the present case: in one instance, the application of vinegar every evening before sun-set produced a happy effect; possibly washing the parts exposed with extract of saturn properly diluted might prove effectual. In the Philosophical Transactions for the year 1767, is an account of uncommonly numerous swarms of gnats which made their appearance at Oxford, during the months of July, August, and September of the preceding year. So many myriads sometimes occupied the same part of the atmosphere in contiguous bodies, that they resembled a very black cloud, greatly darkened the air, and almost totally interrupted the solar rays. The repeated bites of these malignant insects were so severe, that the legs, arms, heads, and other parts of many persons were swelled to an enormous size. The colour of the parts was red and fiery, perfectly similar to that of some of the most alarming inflammations. Some of these gnats had their bodies greatly distended by the uncommon quantities of blood which they had imbibed. In short, there is no species of insects more troublesome to mankind than the gnat; others give more pain with their stings, but it is only when they are attacked, or by accident, that we are stung by them; but the gnats thirst for our blood, and follow us in whole companies to attack us. In marshy places of this country the limbs of the inhabitants are kept swelled during the whole season. In warmer climates, particularly the West Indies, they are, under the denomination of musquetoes, still more formidable. Hooke, in his Micrographia, pleads in justification of these terrible little insects, that they do not wound the skin and suck the blood out of enmity or revenge, but through mere necessity, and to satisfy their hunger:—it may be so; and on this account we cannot annex the criminality to them which appertains to such of the highest rank in the scale of the animal creation, who, though not urged by the same powerful motive, pursue a somewhat similar conduct; but those who have experienced their assaults, will scarcely admit this plea as a sufficient apology, or feel themselves amicably disposed towards them; as, from whatever cause their attacks may proceed, the effect is so very unpleasant, as almost to justify the sufferers in addressing them in the language of the frogs in the fable to the boys, “Consider, I beseech ye, that though this may be sport to you, it is death to us,” and ejaculating a wish, that they might be enabled to gratify their rapacious appetites by some other means. Edit. OF THE PROBOSCIS OF THE TABANUS OR OX-FLY.Plate XVI. Fig. 1. is a microscopic view of the proboscis of a tabanus, with which it pierces the skins of horses and oxen, and nourishes itself with their blood; Fig. 2. the same of the natural size. The singular and compound structure, together with the wonderful form and exquisite beauty of this apparatus, discovers such a view of the wisdom, power, and greatness of its infinite composer, as must strike with admiration every contemplative observer, and lead him to reflect on the weakness, impotence, and nothingness of all human mechanism, when compared with the immense skill and inimitable finishing displayed in the subject before us. The whole of this formidable apparatus is composed of six parts, exclusive of the two guards or feelers a a, all of which are inclosed in a fleshy case, which in the figure is totally removed, as it contained nothing remarkably different from that Many other instances of the variety and curious fabrication of this little organ in different insects, may be found in the works of Reaumur and De Geer; enough has been said to shew that its mechanism not only eludes the human eye, but far surpasses every work of man; I shall therefore proceed, in the next place, to notice THE ANTENNÆ OF INSECTS.The antennÆ are fine slender horns consisting of several articulations, moveable in various directions, and constituting one of the discriminating characteristics of insects. They are beautiful in form, and of a very delicate structure, so finely articulated, and so minutely jointed, as to be instantaneously moveable in every direction. They are situated on the fore part of the head. The shape, the length, the number, and kind of articulations, not only vary in different species, but the antennÆ of the male generally differ from those of the female. The greater number of insects have only two antennÆ, but the oniscus, the pagurus, and astacus have four. Regular rows of minute holes are said to have been discovered in the antennÆ. Several insects cover their eyes with them while they sleep. We are far from being certain of the use of this organ; some writers have conjectured that they were the organs of smell and [53] Some have thought them intended to defend the eyes, but though this might seem probable in regard to the short plumose ones, it can never hold good in those that are slender and smooth, which can be of no such service. Others have thought them made for wiping and cleaning the eyes, but for this purpose they are totally unfit; the fore legs of the insect are much better calculated for this use by the hairs or fibrilla with which they are covered. Possibly they may be the organs of smelling, since we evidently find that many insects possess this sense in a very exquisite degree, and yet we see no external organs except these to serve that purpose. Edit. That these observations are not, however conclusive, appears from an experiment of a very ingenious naturalist: being desirous of ascertaining the nature and use of the antennÆ and proboscis of a butterfly, he gently approached one that was flying about in search of food; he observed that it turned the antennÆ about every way, till coming within scent of a flower, it kept them fixedly bent toward that object, directing its course by their guidance, till it arrived at the flower; there they appeared to act as an organ of smell, and that the minute holes with which it is furnished assisted in promoting this operation. When the creature had reached the flower, it hovered over it as with rapture, [54] After all, this subject must for the present remain undecided. Indeed, the bodies of insects are throughout formed of parts so different from ours, that we can probably conceive no more idea of the use of some of their organs, than a man born blind or deaf can of the senses of vision or hearing. They may have senses different from ours, and these may be the organs of them. Edit. The differences in the form, &c. of the antennÆ are characterized by naturalists under the following names: SetaceÆ; are those that, like a bristle, grow gradually taper towards the point or extremity, as in many of the phalenÆ. Filiformes; thread-shaped, and of an uniform thickness. Moniliformes; these are filiform like the preceding, and of a regular thickness, but consist of a series of round knobs, like a necklace of beads, as in the chrysomela. ClavatÆ; formed like a club, increasing gradually from the base to the extremity, as in the papilio, butterfly. CapitatÆ; these are also formed like a club, but the last articulation is larger than the rest, finishing with a kind of capital or head. Fissiles; these are like the former, only that the capitulum or head is divided longitudinally into three or four parts or laminÆ, as in the scarabÆi. PerfoliatÆ; are also capitated, but have the capitulum divided horizontally, and the laminÆ connected by a kind of thread passing through their center, as in the dermestes and dytiscus. PectinatÆ; so called from their similitude to a comb, though they more properly resemble a feather, as in the phalenÆ and elateres; this is most Besides the foregoing terms, the antennÆ are called breviores, or short, when they are shorter than the body; mediocres, or middling, when they are of the same length; and longiores, when they are longer. Near the mouth there is also a species of small filiform articulated antennÆ, called the palpi, or feelers; they are generally four in number, sometimes six; they are placed under and at the sides of the mouth, which situation, together with their size, sufficiently distinguish them from the antennÆ; they are in continual motion, the animal thrusting them in every matter, as a hog would its nose, when in search of food. Some have supposed them to be a kind of hand to assist in holding the food when it is near the mouth. OF THE EYES OF INSECTS.The structure of the eye has always been considered as a wonderful piece of mechanism; the admirable manner in which those of the human species are formed, and the nature of vision, are speculations which cannot but excite the attention of every inquisitive mind. The eyes of insects, though they differ considerably in their construction from those of other animals, are no less objects of our admiration. Indeed, among the exterior parts of insects, none are more worthy of minute investigation, and very few persons are to be found, who can be insensible to the beauties of this organ when exhibited under the microscope, as that instrument alone points out to us the prodigious art employed in their organization, and evidently shews how many wonders escape the unassisted sight. The construction of the eye in insects is not only distinct from that of other animals, but also differs in different species. They vary in number, situation, connection, and figure. In other creatures the eyes are moveable, and two in number, one on each side of the head: in insects, the genus of cancri excepted, the eyes are fixed; they have no eye-brows, but the outer coating is hard and transparent. The greater part of insects have two eyes; in the monoculus they approach so near to each other, as to appear like one; the gyrinus has four eyes, the scorpion six, the spider eight, and the scolopendra three. Of the eyes of insects, some have them single, that is, placed at a small distance from each other; while others are furnished with an indefinite number, all placed in one common case or socket; the latter are generally termed the reticulated eyes. OF THE RETICULATED EYES OF INSECTS.The microscope does not disclose greater wonders, when it exhibits to us millions of animals invisible to the naked eye, where we should suppose nothing living existed, than when it discovers to us hidden beauties in those, which, though they are large enough to be seen by our natural eye, yet in their several minute parts are no ways discernible, but by the assistance of glasses. Thus we readily discern those protuberances on the heads of insects, which are formed by a congeries of eyes; we can even perceive that they consist of a number of lines crossing each other with great regularity and exactness at some little distance, like the meshes of a net. By this we know that they are reticulated The eyes of the libellula, on account of their size, are peculiarly well adapted for microscopical examination; and, by the assistance of the instrument, you will find that they are divided into a number of hexagonal cells, each of which forms a complete eye. The external parts of these eyes are so perfectly smooth, and so well polished, that, when viewed as opake objects, they will, like so many mirrors, reflect the images of all the surrounding objects. The figure of a candle may be seen on their surface multiplied almost to infinity, shifting its beam to each eye, according to the motion given to it by the hands of the observer. Other creatures are obliged to turn their eyes towards the object, but insects have eyes directed thereto, on whatsoever side it may appear: they more than realize the wonderful accounts of fabulous history: poets gave to Argus an hundred eyes; insects are furnished with thousands, having the benefit of vision on every side with the utmost ease and speed, though without any motion of the eye or flexion of the neck. Each of these protuberances, in its natural state, is a body cut into a number of faces; like an artificial multiplying glass; but with this superiority in the workmanship, that as there, every face is plane, here, every one is convex, immensely more numerous, and contained in a much smaller space. If one of these protuberant substances be nicely taken from the head of the insect, washed clean, and placed before the microscope, its structure is elegantly seen, and it becomes an object worthy of the highest admiration. You will find that each of the eyes is an hexagon, varying in its size according to its situation in the head, and that each of them is a distinct convex lens, and has the same effect in forming the image of an object placed before it. Of this Hooke, Catalan, &c. have shewn that these small eyes are furnished with every requisite of vision, and that each of them has the use, the power, and properties of an eye. But we must have recourse to the works of Swammerdam for a full account of the astonishing organization of the eyes of insects. Among other things, he has shewn, that under each facet there is a pyramid of fibres broad at the base, and growing smaller as it proceeds inwards; the pyramid has the same number of sides as the eye, and there are as many hexagonal pyramids, as there are small facets or eyes in the insect. An innumerable number of pulmonary tubes ascend these fibres, terminating in a white fibrous convex membrane; under these membranes there is another, still more delicate and transparent; beneath this, a second species of fibres is transversely applied, like so many beams to support the pyramids that are laid upon them. Still we cannot determine with certainty, how these numerous inlets to sight operate for the service of the animal; they may increase the field of view, augment the intensity of light, and be productive of advantages of which we can have no conception. Hooke computed 14000 of these facets in the two eyes of a drone; Leeuwenhoek reckoned 6036 in the two eyes of a silkworm, when in its fly state; in the eyes of the libellula he reckoned 12544 hexangular lenses. Swammerdam covered the reticulated eyes of certain insects with black paint; in this state they flew at random, and seemed to be deprived of their strength; when they settled, they did not avoid the hand that was going to take hold of them. Reaumur made similar experiments on the eyes of bees, which concurred with those of Swammerdam. Some ephemera flies have four reticulated eyes, two of which are placed as in the common fly; the other two are placed, one beside the other, upon the upper part of the head, and have the appearance of a kind of mushroom, the head extended somewhat beyond the stalk. The first pair are of a brown colour, those of the mushroom form are of a very beautiful citron colour. In some of the fly class, these reticulated eyes are little inferior in colour and brilliance to the brightest gem. The colour varies in different species; in some you find it green, in others red, &c. some have a most elegant changeable colour thrown over them, partly purple, partly green, and partly of that brassy hue, which is seen on the backs of some of our beetles, and which is not equalled by any other production of art or nature. Fig. 3. Plate XVI. is a representation of a small part of the cornea of a libellula, as seen by the microscope; the sides of the hexagons in some positions of the light, appear of a fine gold colour, and divided into three parallel borders. Fig. 4. the same object of its natural size. Fig. 5. Plate XVI. represents a small portion of the cornea of a lobster; here each of the eyes are small squares, not hexagons; a conformation which admits a smaller number in the same surface; so great a number was not necessary in this instance, as the eyes of the lobster are moveable. Fig. 6. the same of its natural size. OF THE EYES OF THE MONOCULUS POLYPHEMUS.The monoculus polyphemus, or king crab, has four eyes, two large and two small ones; the large eyes are formed of a great number of transparent amber-like cones, the small ones of a single cone, “The internal surface of the large eyes, examined with the microscope, is found to be thick set with a great number of small transparent cones, of an amber colour, the bases of which stand downward, and their points upward next the eye of the observer. The cones in general have an oblique direction, except some in the middle of the cornea, about thirty in number, the direction of which is perpendicular. The center of every cone being the most transparent part, and that through which the light passes, on that account the perpendicular or central cones always appear beautifully illuminated at their points. In a word, they are all so disposed, as that a certain number of them receive the light from whatever point it may issue, and transmit it to the immediate organ of sight, which we may reasonably suppose is placed underneath them. The cones are not all of the same length; those on the edges of the cornea are the longest, from whence they gradually diminish as they approach the center, where they are not above half the length of those on the edges. “The structure of the small eyes being less elaborate, their internal appearance, when placed in the microscope, will be described in a few words. They consist of an oval transparent horny plate, of an amber colour, in the center of which stands a single cone, through which and the oval plate the light passes.”[55] [55] See Mr. AndrÉ’s paper with a plate, in the Phil. Trans. for 1782, page 440. OF THE EYES OF A SPIDER.Though the form of this insect is naturally disgusting, yet the eyes make a beautiful object for the microscope. They have generally eight; two on the top of the head, that look directly upwards; two in the front, a little below the foregoing, to discover what passes before it; on each side a couple more, whereof one points sideways forward, the other sideways backward; so that the spider can nearly see all around. These eyes are immoveable, and seem to be formed of a hard transparent horny substance. A portion of each sphere projects externally beyond the socket, the largest part is sunk within it. There is round each eye a circular transparent membrane. Mr. Baker placed the eye of a spider over a pin-hole made through a piece of card, and then applied it as a lens to examine objects; he found it magnified the objects greatly, but that it did not exhibit them distinctly; this he however attributed to the length of time the spider had been dead whose eye he used. The number of eyes is not the same in all species of the spider. OF THE STEMMATA.It might be imagined, that as every fly has two reticulated eyes, they could not have occasion for more; but so it has not appeared to that GREAT BEING who formed them, for many are furnished besides with other eyes, differing in form and construction from those that are reticulated. These were first noticed by M. de la Hire; they are three lucid protuberances placed on the back part of the head of many insects: their surface is glossy, of an hemispheric figure, and a coal black colour. They are transparent, and disposed in a triangular form; by modern naturalists they are termed stemmata. Reaumur made experiments on these eyes, similar to those he had made on the reticulated ones, and found that when the stemmata were covered with dark varnish, the insects flew but to a small distance, and always at random. No insect is, I believe, found with both kind of eyes, unless in its perfect state: there are many species which are not furnished with stemmata, gnats and tipulÆ are without them. We are apt to suppose that nature has lavished all her bounty upon her larger creatures, and left her minims of existence, as Shakspeare phrases it, unfinished; with what different ideas must those be impressed, who find the apparatus for vision in these small creatures so various and so wonderful in their structure, and who must perceive so much design and order manifested in the position, construction, and number of these delicate and useful organs. OF THE BODY OF INSECTS.The trunk or body of the insect is situated between the head and abdomen. Naturalists divide it into three parts; the thorax, scutellum, and sternum. The thorax is the upper part of the body, it is of various shapes and proportions; the sides and back of it are often armed with points. The scutellum, or escutcheon, is the lower part of the body, and is generally of a triangular form; though it adheres to the thorax, it is easily distinguished therefrom by its figure, and often by an intervening suture. It seems intended to assist in expanding the wings. The sternum is situated on the under part of the thorax; in some species it is pointed behind, as in the elateres; in others, bifid, as in some of the dytisci. OF THE ABDOMEN OF INSECTS.The abdomen, or under part of the body, contains the stomach, the intestines, the air vessels, &c. It is composed of several rings or segments, so that it may be moved in various directions, or lengthened and shortened at pleasure; in some it is formed of one piece only. It is perforated with spiracula, or breathing holes, and is terminated by the tail. The spiracula are small oblong holes or pores placed singly one on each side of every ring of the abdomen; these are the means or instruments of respiration, supply the want of lungs, and form a peculiar characteristic of insects. OF THE LIMBS OF INSECTS.By the limbs are here meant the instruments used by the insect both for motion and defence. They are, alÆ, the wings; halteres, the poisers; pedes, the legs; cauda, the tail; and aculeus, the sting. OF THE WINGS OF INSECTS.The wings are those organs by which the insect is enabled to fly; some have only two, others are furnished with four, two on each side; these are, in some, of the same size; in others, the superior ones are much larger than the inferior: LinnÆus has made them the foundation of the order into which he has divided this numerous class of beings. The variety in the form and structure The following names are made use of to describe the different kinds of wings. They are first distinguished, with respect to their surfaces, into superior and inferior. The part next the head is called the anterior part; that nearer the tail, the posterior part. The interior part is that next the abdomen; the exterior part is the outermost edge. Those wings are termed plicatiles, which are folded when the insect is at rest, as in the wasp. PlanÆ; those which are incapable of being folded. ErectÆ; whose superior surfaces are brought in contact when the insect is at rest, as in the ephemera, papiliones, &c. Patentes; if they are extended horizontally when the insect is at rest, as in the phalÆnÆ geometrÆ. Incumbentes; those insects which, when they are not in motion, cover horizontally with their wings the superior part of the abdomen. DeflexÆ; The wings are further distinguished by their ornaments, being painted with spots, maculÆ; bands, fasciÆ; streaks, strigÆ: when these are extended lengthways, they are called lines, linÆ; and if with dots, punctÆ; one or more rings are termed eyes, ocelli; if the spots are shaped like a kidney, they are termed stigmata. The elytra, or crustaceous cases of the wings are extended when the insect flies, and shut when it rests, forming a longitudinal suture down the middle of the back; they are of various shapes, and distinguished by the following names: Abbreviata; when they are shorter than the abdomen. Truncata; when their extremities terminate in a transverse direct line. Fastigiata; when of equal or greater length than the abdomen, and terminating in a transverse line. Serrata; having their external margins edged with teeth or notches. Spinosa; when their exterior surfaces are covered with small sharp points. Scabra; when they are very rough. Striata; marked with slender longitudinal furrows. Porcata; having sharp longitudinal ridges. Sulcata; with deep furrows. They are likewise distinguished by the denomination of Hemelytra, when their cases are neither so hard as the elytra, nor so delicate as the transparent wings. OF THE HALTERES OR POISERS OF INSECTS.Under the wings of most insects which have only two, there is a small head placed on a stalk, frequently under a little arched scale; these are called halteres, poisers; they appear to be rudiments of the hinder wings: it has been supposed that they serve to keep the body in equilibrio when the insect is flying. OF THE ELYTRA, AND WINGS UNDER THE ELYTRA.I have already observed, that the delicate and transparent wings of many insects are covered and protected by elytra, or cases, which also in some measure act as wings. These exterior cases are harder and more opake than the wings under them; they are generally highly polished, and often enriched with various colours, adorned with ornamental flutings, and studded with brilliants, whose beauties are beyond description. All these ornaments are united in the curculio imperialis,[56] or diamond beetle, one of the richest and most magnificent creatures in nature; the head, the wings, the legs, &c. are curiously beset with scales of a most splendid appearance, outvying the ruby, saphire, and emerald, forming in miniature one of the most noble phenomena that the colours of light can exhibit. It is said, that in the Brazils, from whence they come, it is almost impossible to look at them on a sunny day, when they are flying in little swarms, so great is the glowing splendor of their heightened colours. [56] FabriciÚs Spec. Ins. 184. 129.—Drury. Ins. 2 Tab. 33, Fig. 1. The strength and hardness of the elytra are admirably adapted to the various purposes of the insects to which they are appropriated; at the same time that they protect the tender wings beneath OF THE WINGS OF THE FORFICULA AURICULARIA, OR EARWIG.Fig. 1. Plate XIV. is a magnified view of the wing of an earwig. Fig. 2. the natural size. Though the insect is so very common, yet few people know that it has wings, and fewer yet have seen them; they are of a curious and elegant texture, and wonderful structure. The upper part is crustaceous and opake, while the other part is beautifully transparent. They fold up into a very small compass, and lie neatly concealed under the elytra, which are not more than a sixth part of the wing in size. They first fold back the parts A B, and then shut up the ribs like a fan; the strong muscles used for this purpose are seen at the upper part of the figure. The ribs are extended from the center to the outer edge, others are extended only from the edge about half-way; but they are all united by a kind of band, at a small, but equal distance from the edge; the whole evidently contrived to strengthen the wing, and facilitate the various motions thereof; so that, in these wings you find all the motions that are in the most elaborate and portable umbrellas, executed with a neatness and elegance surpassing description. The earwig is a very destructive animal, doing considerable injury to most kinds of wall fruit, to carnations, and other fine flowers, &c. and as they only OF THE WINGS OF THE HEMEROBIUS PERLA.So infinite is the variety displayed in the disposition, structure, and ornaments of the wings of insects, that only to enumerate them would fill many pages; I must leave this subject to be further pursued by the reader, contenting myself with presenting him with the view of a wing of the hemerobius perla, as it appears under the microscope. The insect to which it belongs, has acquired the name of hemerobius, from the shortness of its life, as it seldom lives more than two or three days in the fly state. LinnÆus has placed it in his fourth class, among those insects which have four transparent wings and no sting. The body of the insect is of a fine green colour; the eyes appear like two delicate beads of burnished gold, whence it is by many called the golden eye. The wings are delicate and elegant, nearly of a length, and exactly similar; they are composed of a beautiful thin transparent membrane, furnished with slender fine ribs, regularly and elegantly disposed, adorned with hairs, and slightly tinged with green. Fig. 1. Plate XV. exhibits its magnified appearance; Fig. 2. the natural size. OF THE WINGS OF MOTHS AND BUTTERFLIES.The wings of these insects are mostly farinaceous, being covered with a fine dust, which renders them opake, and produces those beautiful and variegated colours by which they are so richly adorned, and so profusely decked. If this be wiped off, you find the remaining part, or naked wing, to consist of a number of ribs, like those in the leaves of plants; but of a crustaceous or talcy nature; the largest rib runs along and fortifies the exterior edge of the wing; the interior edge is strengthened by a smaller vessel or rib. The ribs are all hollow, by which means the wing, though comparatively large, is very light. The substance between the ribs, and which constitutes the body of the wing, resembles talc,[57] surprizingly thin and transparent; as this is extremely tender, one use of the scales may be to protect it from injuries. When the moth emerges from the chrysalis, the wings are soft and thick, and if they be examined in that state, will be found to consist of two membranes, that may be raised up and separated, by blowing between them with a small tube: the ribs [57] As the author’s idea of this substance being of the nature of talc, does not appear correct, and I cannot find that entomologists are agreed in the definition of it, I shall just give the following extract on the subject from the Cyclopoedia by Rees, and submit the decision to the reader. “The substance which connects and fills up the spaces between these ribs, is of so peculiar a nature, that it is not easy to find any name to design it by, at least there is no substance that enters the composition of the bodies of the larger animals, that is at all analogous to it. It is a white substance, transparent and friable, and seems indeed to differ in nothing from that of the large and thick ribs, but in that it is extended into thin plates; but this is saying little toward the determining what it really is, since we are as much at a loss to know by what name to call the substance they are composed of. Malpighi indeed calls them bones; but though they do serve in the place of bones, rendering the wing firm and strong, &c. yet, when strictly examined, they do not appear to have any thing of the structure of bones, but appear rather of the substance of scales, or of that sort of imperfect scales, of which, the covering of crustaceous insects is composed.” Edit. Ever since the microscope was invented, the dust that covers these wings has engaged the attention of microscopic observers; as by this instrument it is found to be a regular collection of organized scales of various shapes, and in whose construction there is as much symmetry, as there is beauty in their colours. A view of some of these scales, as they appear in the microscope, is exhibited at F E H I, in Fig. 7. Plate XVI. and in Fig. 8. of the natural size. Their shapes are not only very different in moths of various species, but those on the same moth are also found to differ. Of the scales, some are so long and slender that they resemble hairs, except that they are a little flattened and divided at the ends; some are short and broad; some are notched at the edges, others smooth; some are nearly oval, while others are triangular: they are mostly furnished with a short stalk or stem to fix them to the wing. With the microscope, a variety of large stripes or ribs are to be discovered; between these larger lines, minuter ones may be seen with a deep magnifier. The larger stripes rise in general from the exterior notches; some have a rib running down the middle, through their whole length. The upper and under parts of the wing are equally supplied with them. The regular arrangement of these plates, one beside and partly covering the other, as in the tiling of an house, is best seen by examining a wing in the opake microscope. The prodigious number of small scales which cover the wings of these beautiful That the lively and variegated colours, which adorn the wings of the moth and butterfly, arise from the small scales or plates that are planted therein, is very evident from this, that if they be brushed off from it, the wing is perfectly transparent: but whence this profusion and difference of colour on the same wing? is a question as difficult to resolve, as that of Prior, when he asks.
As the wings of the moths and butterflies are very light, they can support themselves for a long time in the air; their manner of flying is ungraceful, generally moving in a zigzag line, to the right and to the left, alternately ascending and descending; this undulating motion however has its uses, as it disappoints the birds who chase them in taking aim; by which means they frequently elude their pursuit, though continued for a considerable time. Dr. Hooke[58] endeavoured to investigate the nature of the motions of the wings of insects; and, although he was not able, from the experiments he made, to give a satisfactory account of them, yet as they may be useful to some future inquirer, and lead him more readily into the path of truth, I hope an extract therefrom will not prove unacceptable to the reader. To investigate the mode or manner of moving their wings, he considered with attention those spinning insects that suspend, or as it were poise [58] Hooke’s Micrographia, p. 172. PEDES THE FEET, AND LEGS OF INSECTS.These are admirably adapted for their intended service, to give the most convenient and proper motion, and, from the variety in The legs of insects are generally divided into four parts. The first, which is usually the largest, is called the femur; the second, or tibia, is joined to the former, and is commonly of the same size throughout, and longer than the femur; this is followed by the third part, which is distinguished by the name of tarsus, or foot; it is composed of several joints, the one articulated to the other, the number of rings varying in different insects; the tarsus is terminated by the unguis, or claw. The writers on natural history, in order to render their descriptions clear and accurate, have given several names to the legs of insects, from the nature of the motions produced by them. Thus cursorii, from that of running; these are the most numerous. The saltatorii, those that are used for leaping; the thighs of these are remarkably large, by which means they possess considerable strength and power to leap to great distances. The natatorii, those that serve as oars for swimming; the feet of these are flat and edged with hairs, possessing a proper surface to strike against the water, as in the dytiscus, notonecta, &c. Such feet as have no claws are termed mutici. The chelÆ, or claws, are an enlargement of the extremity of the fore feet, each of which is furnished with two lesser claws, which act like a thumb and finger, as in the crab. The under part of the feet in some insects is covered with a kind of brush or sponge, by which they are Motion is one of the principal phenomena of nature; it is as it were the soul of our system, and is as admirable in the smallest animal, as in the universe at large. It is the principal agent in producing all that diversity and change which perpetually affect every object in the creation. The motions of animals are proportioned to their weight and structure, a flea can leap to the distance of at least two hundred times its own length; were an elephant, a camel, or an horse to leap in the same proportion, their weight would crush them to atoms. The same remark is applicable to spiders, worms, and other insects; the softness of their texture, and the comparative smallness of their specific gravity, enable them to fall without injury from heights that would prove fatal to larger and heavier animals.[59] [59] The parts of some of the larger animals are, however, so admirably constructed for swiftness, as to enable them to perform surprizing acts of agility; for instance, the Siberian jerboa, mus saliens, Pennant; this animal springs forward by successive leaping so very nimbly, that it is said to be very difficult for a man well mounted to overtake it; it is about the size of a large rat. The kanguroo, opossum of Pennant, macropus giganteus, Shaw, leaps to so uncommon a height, and to so great a distance, as to outstrip the swiftest greyhound; its size is that of a full-grown sheep. Accurate coloured figures of both these extraordinary animals are given in that elegant work, the Naturalist’s Miscellany. Edit. Many insects can only move the thigh in a vertical direction, while others can move it in a variety of ways. The progressive motion of insects, and the various methods employed to effect it, will be found a very curious and important subject, and well worthy the attention of the naturalist. The intelligent mechanic will not find it lost labour if he bestow some time on the same subject. Very little has been done on this head, and that principally OF THE TAIL AND STING OF INSECTS.Cauda, the tail, terminates the abdomen, and is constructed in a wonderful manner for answering the purposes for which it is formed, namely, to direct the motion of the insect, to serve as an instrument of defence, or for depositing the eggs; the figure and size thereof varying in each genus and its families. In most insects it is simple, simplex, and yet capable of being extended or drawn back at pleasure; in others, elongata, elongated, as in the crab and scorpion; setacea, shaped like a bristle, as in the raphidia; triseta, with three appendages like bristles, as in the ephemera; in some it is forked, furcata, as in the podura; and in others it is furnished with a pair of forceps, forcipata, as in the forficula; in the blatta, grylli, and others, it is foliosa, or like a leaf; in the scorpion and panorpa it is telifera, furnished with a dart or sting. Further particulars may be obtained from the Philosophia Entomologica of Fabricius. Aculeus, or the sting, is an instrument with which insects wound and instil a poison; the sting generally proceeds from the under part of the last ring of the belly: in some it is sharp and pointed, in others serrated or formed like a saw. It is used by many insects both as an offensive and defensive weapon; by others it is only used to pierce the substances where they mean to deposit their eggs. This instrument cannot be properly seen or known, but with the assistance of a microscope. OF THE STING OF A BEE.Of bees, it is only the labourers and the queen that have stings. The apparatus is of a very curious construction, fitted for inflicting a wound, and at the same time conveying poison into that wound. The apparatus consists of two piercers conducted in a sheath, groove, or director. This groove is rather large at the base, but terminates in a point; it is affixed to the last scale of the upper side of the abdomen by thirteen thin scales, six on each side, and one behind the rectum. These scales inclose the rectum all round, and are attached to each other by thin membranes which allow of a variety of motions; three of them are however attached more closely to a round and curved process, which comes from the basis of the groove in which the sting lies, as also to the curved arms of the sting which spread out externally. The two stings may be said to begin by those two curved processes at their union with the scales, and converging towards the groove at its base, which they enter, and then pass along to its point. The two stings are serrated or notched towards the points; they can be thrust out a little way, and drawn within it. These parts are all moved by very strong muscles, which give motions in almost all directions, but most particularly outwards. It is wonderful how deep they will pierce solid bodies with this sting. To perform this by mere force, two things are necessary, power of muscles, and strength of sting; neither of which they seem to possess in a sufficient degree. Mr. J. Hunter thinks that it cannot The apparatus for the poison consists of two small ducts, which are the glands that secrete the poison; these lie in the abdomen among the air cells, they soon however unite into one oblong bag; at the opposite end of which a duct passes out, which runs towards the angle where the two stings meet, and, entering between them, forms a canal by the union of the two stings at this point. From the serrated construction of the stings the bee can seldom disengage them, and hence, when they pass into materials of too strong a nature, the bee generally leaves them behind, and often a part of the bowels therewith.[60] [60] Phil. Trans. for 1792, page 189. DISTINGUISHING CRITERIA OF INSECTS.It has already been observed, that the bodies of insects are covered with a hard skin, answering the purpose of an internal skeleton, and forming one of the characters by which they are distinguished from other animals. This external covering is very strong in those insects which, from their manner of life, are particularly liable to great friction, or violent compression; but is more tender and delicate in such as are not so exposed. The skin of insects, like that of larger animals, is porous; the pores in some species are very large; many insects often change or cast off their skin; this exuvia forms an excellent object for the microscope. Another distinguishing criterion of insects is the colour of their circulating fluid or blood, which is never red; this, at first sight, seems liable to some objections, on account of the drop of red To these discriminating characteristics we may also add the following particulars: 1. That the body of insects is divided by incisurÆ, or transversal divisions, from whence they take their name. 2. That they are furnished with antennÆ, which are placed upon the fore part of the head; these are jointed and moveable in various directions. 3. That no insect in its perfect state, or after it has gone through all its transformations, has less than six legs, though many have more. There are some moths, whose two fore feet are so small, as scarcely to entitle them to that name. 4. That insects have neither the organs of smell nor hearing; at least they have not as yet been discovered, though it is reported that Fabricius has lately found and described the organs of hearing in a lobster.[61] [61] That many insects are susceptible of a shrill or loud noise, is a fact so well ascertained, as to be indisputable; but in what manner, or by what organs the sensation is conveyed, is not so evident; Barbut, however, supposes them to possess the sense of hearing in a very distinct manner. Many insects, he observes, are well known to be endued with the power of uttering sounds, viz. large beetles, bees, wasps, common flies, gnats, &c. The sphinx atropos squeaks, when hurt, nearly as loud as a mouse: this faculty certainly must be intended for some purpose, and as they vary their cry occasionally, it appears designed to give notice of pleasure or pain, or some affection in the creature which possesses it. “The knowledge of their sounds,” says he, “is undoubtedly confined to their tribe, and is a language intelligible to them only; saving when violence obliges the animal to exert the voice of nature in distress, craving compassion; then all animals understand the doleful cry; for instance, attack a bee or wasp near the hive or nest, or a few of them; the consequence will be, the animal or animals, by a different tone of voice will express his or their disapprobation or pain; that sound is known to the hive to be plaintive, and that their brother or brethren require their assistance, and the offending party seldom escapes with impunity. Now, if they had not the sense of hearing, they could not have known the danger their brother or brethren were in, by the alteration of their tone.” Another proof, which he reckons still more decisive, was taken from his observation on a spider, which had made a very large web on a wooden railing, and was at the time in a cavity behind one of the rails, at a considerable distance from the part where a fly had entangled himself; the spider became immediately sensible of it, though, from the situation of the rail, he could not possibly have seen the fly. This observation, however, cannot be considered as conclusive, as it is very probable that the spider was alarmed by the tremulous motion of the threads of the web occasioned by the fluttering of the fly, which he might well know how to distinguish from their vibration by the wind. It is this author’s opinion, that the organ of hearing is situated in the antennÆ; he likewise supposes that the organs of smell reside in the palpi or feelers. For his reasoning on these subjects, see the Genera Insectorum, Preface, p. vii. & seq. Edit. 5. That they do not respire air by the mouth, but that they inspire and exhale it by means of organs which are placed on the body. 6. That they move the jaws from right to left, not up and down. 7. That they have neither eye-lid nor pupil. To these we may also add, that the mechanism resulting from the LIFE of insects is not of so compound a nature as in animals of a larger size. They have less variety of organs, though some of them are more multiplied; and it is by the number and situation of these that their rank in the great scale of beings is to be determined. These characters are often united in the same insect; there are, however, some species in which one or two of them are wanting. The student in entomology, who wishes to attain a proper knowledge of the science, and indeed every microscopic observer, The following general idea of the LinnÆan classes may serve as a foundation for this knowledge: a more particular account may be obtained by consulting the under-mentioned works. Institutions of Entomology, a translation of LinnÆus’s Ordines et Genera Insectorum, or systematic arrangement of insects, &c. by Thomas Pattinson Yeats. Fundamenta EntomologiÆ, or an Introduction to the Knowledge of Insects, translated from LinnÆus by W. Curtis, the ingenious author of Flora Londinensis, the Botanical Magazine, &c. The Genera Insectorum of LinnÆus, exemplified by various [62] This work contains two excellent plates, illustrative of the Distinctions of the Ordines and Genera Insectorum, by their antennÆ, tarsi of the feet, &c. Edit. Class the first. Coleoptera. The insects of this class have four wings; the upper ones, called the elytra, are crustaceous, being of a hard horny substance; these, when shut, form a longitudinal suture down the back, as in the scarabÆus, melolontha, or cockchaffer, &c. 2. Hemiptera. These have also four wings; but the elytra are different, being half crustaceous, half membranaceous: the wings do not form a longitudinal suture, but extend the one over the other, as in the gryllus, grasshopper, &c. 3. Lepidoptera. Those which have four membranaceous wings covered with fine scales, appearing to the naked eye like powder or meal, as in the butterfly and moth. 4. Neuroptera. These have four membranaceous transparent wings, which are generally reticulated, the tail without a sting, as in the libellula, or dragon fly. 5. Hymenoptera. These, like the preceding class, have four membranaceous naked wings; but the abdomen is furnished with a sting, as in the bee, wasp, ichneumon, &c. 6. Diptera. These have only two wings, and are furnished with halteres, or poisers, instead of under wings, as in the common house fly, gnat, &c. 7. Aptera. These are distinguished by having no wings, as in the spider, louse, acarus, &c. OF THE TRANSFORMATION OF INSECTS.Insects are farther distinguished from other animals by the wonderful changes that all those of the winged species without exception, and some which are destitute of wings, must pass through, before they arrive at the perfection of their nature. Most animals retain, during their whole life, the same form which they receive at their birth; but insects go through wonderful exterior and interior changes, insomuch that the same individual, at its birth and middle state, differs essentially from that under which it appears when arrived at a state of maturity; and this difference is not confined to marks, colour, or texture, but is extended to their form, proportion, motion, organs, and habits of life. The ancient writers on natural history were not unacquainted with these transformations, but the ideas they entertained of them were very imperfect and often erroneous. The changes are produced in so sudden a manner, that they seem like the metamorphoses recorded in the fables of the ancients, and it is not improbable that those fables owe their origin to the transformation of insects. It was not till towards the latter end of the last century that any just conception of this subject was formed; the mystery was then unveiled by those two great anatomists Malpighi and Swammerdam, who observed these insects under every appearance, and traced them through all their forms; by dissecting them at the time just preceding their changes, they were enabled to prove that the moth and butterfly grow and strengthen themselves, that their members are formed and unfolded under The life of those insects which pass through these various changes, may be divided into four principal parts, each of which will be found truly worthy of the utmost attention of the microscopic observer. The first change is from the EGG into the LARVA, or, as it is more generally called, into the worm or caterpillar. From the LARVA, it passes into the PUPA, or chrysalis state. From the PUPA, into the IMAGO, or fly state. Few subjects can be found that are more expressive of the extensive goodness of Divine Providence, than these transformations, in which we find the occasional and temporary parts and organs of these little animals suited and adapted with the most minute exactness to the immediate manner and convenience of their existence; which again are shifted and changed, upon the insects commencing a new scene and state of action. In its larva state the insect appears groveling, heavy, and voracious, in the form of a worm, with a long body composed of successive rings; crawling along by the assistance of these, or small little hooks, which are placed on the side of the body. Its head is armed with strong jaws, its eyes smooth, entirely deprived of sex, the blood circulating from the hind part towards the head. It breathes through small apertures, which are situated on each side of the body, or through one or more tubes placed in the hinder part thereof. While it is in the larva state, the insect is as it were masked, and its true appearance concealed; for under this mask the more perfect form is hidden from the human eye. In the pupa, or chrysalis state, the insect may be compared to a child in swaddling cloathes; its members are all folded together under the breast, and inclosed within one or more coverings, remaining there without motion. While in this state, no insects but those of The insect then casts off the spoils of its former state, wakes from a death-like inactivity, breaks as it were the inclosures of the tomb, throws off the dusky shroud, and appears in its imago or perfect form; for it has now attained the state of organical perfection, which answers to the rank it is to hold in the corporeal world: the structure of the body, the alimentary organs, and those of motion, are materially changed. It is now furnished with wings magnificently adorned, soars above and despises its former pursuits, wafts the soft air, chooses its mate, and transmits its nature to a succeeding race. Those members, which in the preceding state were wrapped up, soft, and motionless, now display themselves, grow strong, and are put in exercise. The interior changes are as considerable as those of the exterior form, and that in proportion as the first state differs from the last; some organs acquire greater strength and firmness, others are rendered more delicate; some are suppressed, and some unfolded, which did not seem to exist in the former stages of its life. OF THE LARVA STATE OF INSECTS.As the larvÆ or caterpillars of the moth and butterfly[63] form the most numerous family among the tribe of insects, I shall first [63] Butterflies are distinguished from moths by the time of their flying abroad, and by their antennÆ; the butterflies appear by day, their antennÆ are generally terminated by a little knob; the moths fly mostly in the evening, and their antennÆ are either setaceous or pectinated. The greater part of those insects which come forth in spring or summer, perish or disappear at the approach of winter; there are very few, the period of whose life exceeds that of a year; some survive the rigours of winter, being concealed and buried under ground; many are hid in the bark of trees, and others in the chinks of old walls; some, like the caterpillar of the brown-tailed moth,[64] at the approach of winter not only secure and strengthen the web in which the society inhabit, and thus protect themselves from impertinent intruders, but each individual also spins a case for itself, where it rests in torpid security, notwithstanding the inclemency of the season, till the spring animates it afresh, and informs it, that the all-bountiful Author of nature has provided food convenient for it. Many that are hatched in the autumn retire and live under the earth during the winter months, but in the spring come out, feed, and proceed onward to their several changes; while no small part pass the colder months in their chrysalis or pupa state: but the greater number of the caterpillar race remain in the egg, being carefully deposited by the parent fly in those places where they will be hatched with the greatest safety and success; in this state the latent principle of life is preserved till the genial influences of the spring call it into action, and bring forth the young insect to share the banquet that nature has provided. [64] This moth was uncommonly numerous and destructive near London in the year 1782, and, aided by the predictions of an empirical imposter, occasioned a considerable alarm in the minds of the ignorant and superstitious. The judicious publication of a short history of the insect, by Mr. Curtis, in some measure contributed to dissipate their fears. Edit. All caterpillars are hatched from the egg, and when they first proceed from it are generally small and feeble, but grow in strength as they increase in size. The body is divided into twelve rings; the head is connected with the first, and is hard and crustaceous. No caterpillar of the moth or butterfly has less than eight, or more than sixteen feet; the six first are crustaceous, pointed, and fixed to the three first rings of the body; these feet are the covering to the six future feet of the moth; the other six feet are soft and flexible or membranaceous; they vary both in figure and number, and are proper only to the larva state; with respect to their external figure, they are either smooth or hairy, soft to the touch, or hard like shagreen, beautifully adorned with a great variety of the most lively teints; on each side of the body nine little oval holes are placed, which are generally considered as the organs of respiration. There are on each side of the head of the caterpillar five or six little black spots, which are supposed to be its eyes. These creatures vary in size, from half an inch long to four and five inches. The caterpillar, whose life is one continued succession of changes, often moults its skin before it attains its full growth; not one of them arrives at perfection, without having cast its skin at least once or twice. These changes are the more remarkable, because when the caterpillar moults, it is not simply the skin that is changed; for we find in the exuvia, the skull, the jaws, and all the exterior parts, both scaly and membranaceous, which compose its upper and under lip, its antennÆ, palpi, and even those crustaceous pieces within the head, which serve as a fixed basis to a number of muscles; we further find in the exuvia, the spiracula, the claws, and sheaths of the anterior limbs, and in general all that is visible of the caterpillar. The new organs were under the old ones as in a sheath, so that the caterpillar effects the changes by withdrawing itself from the old skin, when it finds itself lodged in too narrow a compass. But to produce this change, to push off the old covering, and bring forward the new, is a work of labour and time. Those caterpillars who live in society, and have a kind of nest or habitation, retire there to change their skins, fixing the hooks of the feet, during the operation, firmly in the web of their nest. Some of the solitary species spin at this time a slender web, to which they affix themselves. A day or two before the critical moment approaches, the insect ceases to eat, and loses its usual activity; in proportion as the time of change advances, the colour of the caterpillar becomes more feeble, the skin hardens and withers, and is soon incapable of receiving those juices by which it was heretofore nourished and supported. The insect may now be seen, at distant intervals, to elevate its back, and stretch itself to its utmost extent; sometimes to lift up the head, move it a little from side to side, and then let it fall again; near the change, the second and third rings are seen to swell considerably; by these internal efforts the old parts are stretched and distended as much as possible, an operation which is attended with great difficulty, as the new parts are all weak and tender. However, by repeated exertions, all the vessels which conveyed the nourishment to the exterior skin are disengaged, and cease to act, and a slit is made on the back, generally beginning at the second or third ring; the new skin may now be just perceived, being distinguished by the freshness and brightness of its colour; the caterpillar then presses the body like a wedge into this slit, by which means it is soon opened from the first down to the fourth ring; this renders it large enough to afford the insect a passage, which it soon effects in a very curious manner. The caterpillar generally fasts a whole day after each moulting, for it is necessary [65] Valmont de Bomare Dictionnaire Universel d’Histoire Naturelle, vol. ii. 2d edit. 12mo. p. 394. Before we describe the change of the larva into the pupa state, it will be necessary to give the reader an account of those names by which entomologists distinguish the different appearances of the insect in its pupa state. It is called Coarctata, when it is straitened or confined to a case of a globular form, without the smallest resemblance to the structure of the insect it contains, as in the diptera. It is called Obtecta, disguised or shrouded, when the insect is inveloped in a crustaceous covering, consisting of two parts, one of which surrounds the head and thorax, the other the abdomen. It is termed Incompleta, when the pupa has perceptible wings and feet, but cannot move them, as in most of the hymenoptera. Semicompleta; these can walk or run, but have only the rudiments It is a general rule, that all winged insects pass through the larva and pupa state, before they assume their perfect form: there are also insects which have no wings, and yet undergo similar transformations, as the bed bug, the flea, &c. Other insects, which have no wings, and which always remain without them, never pass through the pupa state, but are subject to considerable changes, as well with respect to the number, as the figure of their parts; thus mites have four pair of feet, and two smaller ones at the fore part of the body, near the head; yet some of these are born with only three pair of feet, the fourth is not perceived till some time after their birth.[66] The figure of the monoculus quadricornis of LinnÆus (Fauna Suecica, edit. Stockholm, 1761, No. 2049) changes considerably after its birth.[67] The julus is an insect with a great number of feet, some species having an hundred pair and upwards. M. De Geer has given a description of one with more than two-hundred pair,[68] and yet these at their birth have only three pair, the rest are not perceived till some time after. [66] De Geer Memoires pour servir a l’Histoire des Insectes, tom. 1. p. 154. [67] Ibid. [68] Memoires des Scavans etrangers, tom. 3, p. 61. OF THE CHANGE FROM THE LARVA TO THE PUPA STATE.I shall now return to the caterpillar, and take notice of the care and provision it makes to pass from the larva state into that of the pupa or chrysalis; which is, in general, a state of imperfection, inactivity, and weakness, through which the insect, when it has obtained a proper size, must pass; and in which it remains often for months, sometimes for a whole year, exposed, without any means of escaping, to every event; and in which it receives the necessary preparations for its perfect state, and is enabled once more to appear upon the transitory scene of time. During its passage from one state to the other, as well as when it is in the pupa form, the microscopical observer will find many opportunities of exercising his instrument. The transitions of the caterpillar from one state to another, are to it a subject of the most interesting nature; for in passing through them, it often runs the risk of losing its life, that precious boon of heaven, which is ever accompanied with a degree of delight, proportioned to the state in which the creature exists, and the use it makes of the gift it has received. If the caterpillar could therefore foresee the efforts and exertions it must make to put off its present form, and the state of weakness and impotence under which it must exist while in the pupa state, it would undoubtedly choose the most convenient place, and the most advantageous situation, for the performance of this arduous operation; one where it would be the least exposed to danger, at a time when it had neither strength to resist, nor swiftness to avoid the attack of an enemy. All these necessary instructions the caterpillar receives from the influence of an all-regulating Providence, which conveys the proper information to it by its own sensations: hence, when the critical period approaches, it When the caterpillar has attained to its full growth, and the parts of the future butterfly are sufficiently formed beneath its skin, it prepares for its change into the pupa state; it seeks for a proper place in which to perform the important business: the different methods employed by these little animals to secure this state of rest, may be reduced to four: 1. Some spin webs or cones, in which they inclose themselves. 2. Others conceal themselves in little cells, which they form under ground. 3. Some suspend themselves by their posterior extremity; 4. While others are suspended by a girdle that goes round their body. I shall describe the variety in these, as well as the industry used in constructing them, after we have gone through the manner in which the caterpillar prepares itself for, and passes through the pupa state. Preparatory to the change, it ceases to take any food, empties itself of all the excrementitious matter that is contained in the intestines, voiding at the same time the membrane which served as a lining to these and the stomach. The intestinal canal is composed of two principal tubes, the one inserted into the other; the external tube is compact and fleshy, the internal one is thin and transparent; it is the inner tube, which lines the stomach and intestines, that is voided with the excrement before the change. It generally perseveres in a state of rest and inactivity for several days, which affords the external and internal organs that are under the skin an opportunity of gradually unfolding themselves. In proportion as the change into the pupa form approaches, the body is observed often to extend and contract itself; The caterpillar, thus stripped from its skin, is what we call the pupa, chrysalis, or aurelia, in which the parts of the future moth are inclosed in a crustaceous covering, but are so soft, that the slightest touch will discompose them. The exterior part of the chrysalis is at first exceedingly tender, soft, and partly transparent, being covered with a viscous fluid; this soon dries up, thickens, and forms a new covering for the animal, capable of resisting external injuries; a case, which is at the same time the sepulchre of the caterpillar, and the cradle of the moth; where, as under a veil, this wonderful transformation is carried on. The pupa has been called a chrysalis, or creature made of gold, from the resplendent yellow colour with which some kinds are adorned. Reaumur has shewn us whence they derive this rich colour; that it proceeds from two skins, the upper one a beautiful brown, which lies upon or covers a highly polished and smooth white skin: the light reflected from the last, in passing through, gives it the golden yellow, in the same manner as this colour is Those who are desirous to discover distinctly the various members of the moth in the pupa, should examine it before the fore-mentioned fluid is dried up, when it will be found to be only the moth with the members glued together; these, by degrees, acquire sufficient force to break their covering, and disengage themselves from the bands which confine them. While in this state, all the parts of the moth may be traced out, though so folded and laid together, that it cannot make any use of them; nor is it expedient that it should, as they are too soft and tender to be used, and pass through this state merely to be hardened and strengthened. To examine the moth concealed under the skin of a caterpillar, one of them should be taken at the last change; when the skin begins to open, it should be drowned in spirit of wine, or some strong liquor, and be left therein for some days, that it may take more consistency and harden itself; the skin of the caterpillar may then be easily removed: the chrysalis, or feeble moth, will be first discovered, after which the tender moth may be traced out, and its wings, legs, antennÆ, &c. may be opened and displayed by an accurate observer. The parts of the moth or butterfly are not disposed exactly in the same manner in the body of the caterpillar, as when left naked in the chrysalis. The wings are longer and narrower, being wound up into the form of a cord, and the antennÆ are rolled up on the head; the tongue is also twisted up and laid upon the head, but in a very different manner from what it is in While in this state, the creature generally remains immoveable, and seems to have no other business but patiently to attend the time of its change, which depends on the parts becoming hard and firm, and the transpiration of that humidity which keeps them soft; the powers of life are as it were absorbed in a deep sleep; the organs of sensation seem obliterated, being imprisoned by coverings more or less strong, the greater part remains fixed in those situations which the caterpillar had selected for them till their final metamorphosis; some, however, are capable of changing place, but their movements are slow and painful. The time, therefore, which the moth or butterfly remains in the pupa state is not always the same, varying in different species, and depending also upon the warmth of the weather, and other adventitious circumstances; some remain in that situation for a few weeks; others do not attain their perfect form for eight, nine, or eleven months: this often depends on the season in which they assume the pupa form, or rather on the time of their birth. Some irregularities are also occasioned by the different temperature of the air, by which they are retarded or accelerated, so as to be brought forward in the season best suited to their nature and the ends of their existence. I have heard of an instance, where the pupa, produced from caterpillars of the same eggs, nourished in the same manner, and which all spun up within a few days of each other in the autumn, came into the fly state at three different and distant periods; viz. one-third of them the [69] Reaumur Memoires sur les Insectes, tom. 2, mem. 1. There are some caterpillars which remain in their cone eight or nine months before they acquire the complete pupa state; so that their duration in that form is much shorter than it naturally appears to be. OF THE PREPARATION OF THE CATERPILLAR FOR THE METAMORPHOSES.The industry of the caterpillar, in securing itself for its change into the chrysalis, must not be passed by; not only because it naturally leads the reader to consider and admire that divine agency, by which the insect is informed, but because the different modes it makes use of cannot be properly investigated, without the assistance of glasses, it therefore consequently becomes a proper subject for the microscope; we shall select from a great variety, a few instances, to animate the reader in these researches. Some caterpillars, towards the time of their change, suspend themselves from the branch of a tree, with the head downwards; in this position they assume the pupa form, and from thence immerge OF THE IMAGO OR FLY STATE OF INSECTS.As soon as the moth acquires sufficient strength to break the bonds which surround it, and of which it is informed by its internal sensations, it makes a powerful effort to escape from its prison, and view the world with new-formed eyes. The moth frees itself from the pupa with much greater ease than the pupa from the caterpillar; for the case of the pupa becomes so dry, when the moth is near the time of throwing off its covering, that When the moth first sees the day, it is humid and moist; but this humidity soon evaporates, the interior parts dry and harden In the progress of these insects, such changes take place, as we could have formed no conception of, if the great Author of these wonders had not been pleased to reward the industrious naturalist with the discovery. If the moth be opened down the belly, and the unctuous parts which fill it, be removed, the gross artery, which has been called the heart, will be visible, and the contractions and dilatations, by which it pushes forward the liquor it contains, may be easily observed. The food of the caterpillar is gross and solid, and even this it is obliged to earn with much labour and danger; but, when freed as it were from the jaws of death, and arrived at its perfect form, the purest nectar is its potion, and the air its element. It was supplied with coarse food, in the first state, by the painful operation of its teeth, which was afterwards digested by a violent trituration of the stomach. The intestines are now formed in a more delicate manner, and suited to a more pure and elegant aliment, which nature has prepared for its use from the most fragrant and beautiful flowers. Many internal parts of the caterpillar disappear in the chrysalis, and many that could not be perceived before, are now rendered visible: the interior changes are not less surprizing than those of the exterior form, and are, properly speaking, creative of them; for it is from these the exterior form originates, and with these it always corresponds. In a word, the creature that heretofore crept upon the earth, now flies freely through the air; and far from creating our aversion by its frightful prickles and foul appearance, it attracts our notice by the most elegant shape and apparel, and, from being scarce able to move from one shrub to another, acquires strength and agility to tower far above the tallest inhabitant of the forest. OF THE SILK-WORM.The industry of those that spin cones or cases, in which they inclose themselves, in order to prepare for their transformation in security, is more generally known, as it is from one species of these that we derive so many benefits, namely from the silk-worm, whose works afford an ornament for greatness, and add magnificence to royalty. All caterpillars undergo similar changes with it, and many in the butterfly state greatly exceed it in beauty: but the golden tissue, in which the silk-worm wraps itself, far surpasses the silky threads of all the other kinds; they may indeed come forth with a variety of colours, and wings bedecked with gold and scarlet, yet they are but the beings of a summer’s day; both their life and beauty quickly vanish, and leave no remembrance after them; but the silk-worm leaves behind it such beneficial monuments, as at once record the wisdom of its Creator, and his bounty to man.[70] [70] Pullein on the Culture of Silk. The substance of which the silk is formed, is a fine yellow transparent gum, contained in two reservoirs that wind about the intestines, and which, when they are unfolded, are about ten inches long; they terminate in two exceeding small orifices near the mouth, through which the silk is drawn, or spun to the degree of fineness which its occasions may require. This apparatus has been compared to the instrument used by wire-drawers, and by which gold and silver is drawn to any degree of minuteness. From each of these reservoirs proceeds a thread, which are united afterwards; so that if it be examined by the microscope, it will be found to consist of two cylinders or threads glued together, with a groove in the middle; a separation may sometimes be perceived. When the silk-worm has found a convenient situation, it sets to work, first spinning some random threads, which serve to support the future superstructure; upon these it forms an oval of a loose texture, consisting of what is called the floss-silk; within this it forms a firm and more consistent ball of silk, remaining during the whole business within the circumference of the spheroid that it is forming, resting on its hinder parts, and with its mouth and fore legs directing and fastening the threads. These threads are not directed in a regular circular form, but are spun in different spots, in an infinite number of zig-zag lines; so that when it is wound off, it proceeds in a very irregular manner, sometimes from one side of the cone, then from the other. This thread, when measured, has been found to be about three-hundred yards long, and so fine, that eight or ten are generally rolled off into one by the manufacturers. The silk-worm usually employs about three days in finishing this cone; the inside is generally smeared with a kind of gum, that is designed to keep out the rain: in this cone it assumes the pupa form, and remains therein from fifteen to thirty days, according to the warmth of the climate. When the moth is formed, it moistens the end of this cone, and by frequent motions of the head loosens the texture of the silk, so as to form a hole without breaking it. When the silk-worm has acquired its perfect growth, the reservoirs of silk are full, and it is pressed by its sensations to get rid of this incumbrance, and accordingly spins a cone, the altitude and size of which are proportioned to its wants: by traversing backwards and forwards, it is relieved, and attains by an innate desire the end for which it was formed; and thus a caterpillar, whose form is rather disgusting to the human unphilosophic eye, becomes a considerable object of manufacture and trade, a source of wealth, and, from the extensive employment it affords, a blessing to thousands. The size of the cone is not always proportioned There is a caterpillar which forms its silken cone in the shape of a boat turned bottom upwards, whence it is called by Reaumur the “coque en batteau;” the construction is complicated, and seems to require more art than is usually attributed to this insect. It consists of two principal parts, shaped like shells, which are united with considerable skill and propriety; each shell or side is framed by itself, and formed of an innumerable quantity of minute silk rings; in the fore part there is a projection, in which a small crevice may be perceived, which serves, when opened, for the escape of the moth; the sides are connected with so much art, that they open and shut as if framed with springs; so that the cone, from which the butterfly has escaped, appears as close as that which is still inhabited. Those caterpillars which are not furnished with a silky cone, supply that want with various materials, which they possess sufficient skill to form into a proper habitation, to secure them while preparing for the perfect state; some construct theirs with leaves and branches, tying them fast together, and then strengthening the connection; others connect these leaves with great regularity; many strip themselves of their hairs, and form a mixture of hair and silk; others construct a cone of sand, or earth, cementing the particles with a kind of glue; some gnaw the wood into a kind of saw-dust, and glue it together; with an innumerable variety of modes suited to their present and future state. OF THE BEETLE.To make the reader more fully acquainted with a subject which affords such abundant matter for the exercise of his microscope, The beetle is of the first or coleopterous class, having four wings. The two upper ones are crustaceous, and form a case to the lower ones; when they are shut, there is a longitudinal suture down the back: this formation of the wings is necessary, as the beetle often lives under the surface of the earth, in holes which it digs by its own industry and strength. These cases save the real wings from the damage which they might otherwise sustain, by rubbing or crushing against the sides of its abode; they serve also to keep the wings clean, and produce a buzzing noise when the animal rises in the air. The strength of this insect is astonishing; it has been estimated that, bulk for bulk, their muscles are a thousand times stronger than those of a man! The beetle is only an insect disengaged from the pupa form; the pupa is a transformation in like manner from the worm or larva, and this proceeds from the egg; so that here, as in the foregoing instances, one insect is exhibited in four different states of life, after passing through three of which, and the various inconveniences attendant on them, it is advanced to a more perfect state. When a larva, it trains a miserable existence under the earth; in the pupa form it is deprived of motion, and as it were dead; but the beetle itself lives at pleasure above and under ground, and also in the air, enjoying a higher degree of life, which it has attained by slow progression, after passing through difficulties, affliction, and death. If we judge of the rank which the beetle holds in the scale of animation, from the places where they are generally found, from the food which nourishes them, from the disgusting and odious The egg of the rhinoceros beetle[71] is of an oblong round figure, of a white colour; the shell thin, tender, and flexible; the teeth of the worm that is within the shell come to perfection before the other parts; so that as soon as it is hatched, it is capable of devouring, and nourishing itself with the wood among which it is placed. The larva or worm is curiously folded in the egg, the tail resting between the teeth, which are disposed on each side the belly; the worm in proper time breaks the shell, in the same manner as a chicken, and crawls from thence to the next substance suitable for its food. The worm, when it is hatched, is very white, has six legs, and a wrinkled naked body, but the other parts are all covered with hair; the head is then also bigger than the whole body, a circumstance which may be observed in larger animals, and which is founded on wise reasons.[72] If the egg be observed from time to time while the insect is within it, the beating of the heart may be perceived. The eggs of the earth-worm, the snail, and the beetle, will afford many subjects for the microscope, and will be found to deserve a very attentive examination. Swammerdam was accustomed The worm of the rhinoceros beetle, like other insects in the larva state, changes its skin; in order to effect which, it discharges all its excrement, and forms a convenient hole in the earth, in which it may perform the wonderful operation; for it does not, like the serpent, cast off merely an external covering, but the throat, a part of the stomach, and the inward surface of the great gut, change at the same time their skin: as if it were to increase the wonder, and to call forth our attention to these representative changes, some hundreds of pulmonary pipes cast also each its delicate skin, a transparent membrane is taken from the eyes, and the skull remains fixed to the exuvia. After the operation, the head and teeth are white and tender, though at other times as hard as bone; so that the larva, when provoked, will attempt to gnaw iron. For an accurate anatomical description of this worm, I must refer the reader to Swammerdam; he will find it, like the rest of this author’s works, well worthy of his attentive perusal. To dissect it, he first killed it in spirit of wine, or suffocated it in rain water rather more than lukewarm, not taking it out from thence for some hours. This preparation prevents an improper contraction of the muscular fibres. When the time approaches for the worm to assume the pupa form, it generally penetrates deeper into the ground,[73] or those [73] The larvÆ of those beetles which live under ground are in general heavy, idle, and voracious; on the contrary, the larvÆ which inhabit the waters are exceedingly active. The pupa[74] of this insect weighs, a little after its change, much heavier than it does in its beetle state; this is also the case with When the proper time for the final change arrives, all the muscular parts grow strong, and are thus more able to shake off their last integuments, which is performed exactly in the same manner as in the passage of the insect from the larva to the pupa state; so that in this last skin, which is extremely delicate, the traces of the pulmonary tubes, that have been pulled off and turned out, again become visible. All parts of the insect, and more particularly the wings and their cases, are at this period swelled and extended by the air and fluids which are driven into them through the arteries and pulmonary tubes; the wings are OF THE MUSCA CHAMÆLEON.I shall now proceed to illustrate the nature of the different transformations in insects, by giving an account of the musca chamÆleon. In the worm or larva condition it lives in the water, breathes by the tail, and carries its legs within a little snout near its mouth. When the time arrives for its pupa state, it goes through the change without casting off the skin of the larva. Lastly, in the imago, or fly state, it would infallibly perish in the water, that element which had hitherto supplied it with life and motion, was not the larva by nature instructed where to choose a suitable situation for its approaching transformation. This insect is characterized by LinnÆus as “Musca chamÆleon. Habitat larva in aquis dulcibus; musca supra aquam obambulare solet.” In a former edition of the Fauna Suecica he called it oestrus aquÆ; but on a more minute examination, he found it was a musca; besides, the larvÆ of all known oestri are nourished in the bodies of animals. The larva of this insect appears to consist of twelve annular divisions, see Plate XI. Fig. 1. by these it is separated into a head, thorax, and abdomen; but as the stomach We shall now consider the external figure of this worm, as it appears with the microscope. It is small toward the head, larger about those parts which may be considered as the thorax; it then This worm, the head and tail included, has twelve annular divisions, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, Fig. 3. Plate XI. Its skin resembles the covering of those animals that are provided with a crustaceous habit, more than it does that of naked worms or caterpillars; it is moderately hard, and like the rough skin called shagreen, being thick set with a number of grains, evenly distributed. The substance of the skin is firm and hard, and yet very flexible. On each side of the body are nine spiracula or holes, for the purpose of respiration; there are no such holes visible on the tail ring a, nor on the third ring counting from the head; for at the extremity of the tail there is an opening for the admission and expulsion of air; in the third ring the spiracula are very small, and appear only under the skin, near the place where the embryo wings of the future fly are concealed. It is remarkable that caterpillars, in general, have two rings without these spiracula; perhaps, because they change into flies with four wings, whereas this worm produces a fly that has only two. The skin has three different shades of colour; it is adorned with oblong black furrows, with spots of a light colour, and orbicular rings, from which there generally springs a hair, as in the figure before us, only the hair that grows on the insect’s side is represented; besides this, there are here and there some other larger hairs, c c. The difference of colour in this worm arises from the quantity of grains in the same space; for in proportion as there is a greater or lesser quantity of these, the furrows and rings are of a deeper or paler colour. The head d is divided into three parts, and covered with a skin, the grains on which are hardly discernible. The eyes are rather protuberant, and lie forwards near the snout. It has also two small horns i i, on the fore part of the head. The snout is crooked, and ends in a sharp point as This insect not only walks with these legs at the bottom of the water, but even moves itself on land by means of them; it likewise makes use of them to swim, while it keeps its tail on the surface contiguous to the air, and hangs downward with the rest of the body in the water: in this situation no motion is perceived in it, but what arises from its legs, which it moves in a most elegant manner. It is reasonable to conclude from what has been said, that the principal part of the creature’s strength lies in these legs; nor will it be difficult for those who are acquainted with the nature of the ancient hieroglyphics, which are now opening so clearly, to fix the rank of this insect in animated life, and point out those orders of being, and the moral state through which it receives its form and habits of life. The snout is black and hard, the back part is quite solid, and somewhat of a globular form, whereas the front f, is sharp and hollow; on the back part three membranaceous divisions may be observed, by means of which, and the muscles contained in the snout, the insect can at pleasure expand or contract it. The tail is constructed and planned with great skill and wisdom. The extreme verge or border, is surrounded by thirty hairs, and the sides adorned with others that are smaller; here and there the large hairs branch out into smaller ones, which may be reckoned as single hairs. These hairs are all rooted in the outer skin, which in this place is covered with rough grains, as may be seen by cutting it off, and holding it up, when dry, against the light, upon a thin plate of glass. By the same mode you will find, that at the extremities of the hairs there are also grains like those of the skin; in the middle of the tail there is a small opening, within it are minute holes, by which the insect inhales and expels the air it breathes. The hairs are very seldom disposed in so regular a manner as they are represented in Fig. 3. Plate XI. except when the insect floats with the body in the water, and the tail with its hairs a little lower than the surface, for they are then displayed exactly as delineated in the plate. The least motion downward of the tail produces a concavity in the water, and it then assumes the figure of a wine-glass, wide at the top, narrow at the bottom. The tail serves the larva both for the purposes of swimming and breathing, and it receives through the tail that which is the universal principle of life and motion in animals. By means of the hairs it can stop itself at pleasure when swimming, or remain suspended quietly in the water for any length of time. The motion of the insect in swimming is very beautiful, especially when it advances with its whole body floating on the surface of the water; after filling itself with air by the tail. To set out, it first bends the body to the right or left, and then contracts These larvÆ are generally to be found in shallow standing waters, about the beginning of June, sooner or later, as the summer is more or less favourable; in some seasons they are to be found in great numbers, while in others, it is no easy matter to meet with them. They love to crawl on the plants and grass which grow in the water, and are often to be met with in ditches, floating on the surface of the water by means of their tail, the head and thorax at the same time hanging down; and in this situation they will turn over the clay and dirt with their snout and feet in search of food, which is generally a viscous matter that is common in small ponds and about the sides of ditches. This worm is very harmless, contrary to the opinion one might form at first sight, from the surprizing vibratory motion of the legs, which resembles the brandishing of an envenomed tongue or sting. They are most easily killed for dissection in spirit of turpentine. After a certain period they pass into the pupa form; when they are about to change, they betake themselves to the herbs that float on the surface of the water, and creep gently thereon, till at length they lie partly on the dry surface, and partly on the water; when in the larva or pupa state, they can live in water, but can by no means inhabit there when changed into flies: indeed, man also, whilst in the uterus, lives in water, which he cannot do afterwards. When these worms have found a proper situation, they by degrees contract themselves, and in a manner scarce perceptible lose all power of motion. The inward parts of the worm’s tail now separate from the outmost skin, and become greatly contracted; this probably gives the insect considerable Thus this insect passes into the pupa state under its own skin, entirely different from that of the caterpillar, which casts off the exterior skin at this time; this change may often be observed to take place in the space of ten or twelve hours, but in what manner it is performed we are ignorant, as it is effected in a hidden unknown way, inwardly within the skin, which conceals it from our view. Whilst the larva is changing under the skin, the body, head, and tail, separate insensibly from their outward vesture. The legs at this time, and their cartilaginous bones, are, on account of the parts which are withdrawn from them, left empty; the worm loses also now the former skull, the beak, together with the horny bones belonging thereto, which remain in the skin of the exuvia. It is worthy of notice, that the optic nerves separate also from the eyes, and no more perform their office. The muscles of the rings in like manner, and a great part of the pulmonary points of respiration, are separated from the external skin. Thus the whole body contracts itself by degrees into a small compact mass. At this time the gullet and the pulmonary tubes cast a coat within the skin. To make this evident, it is necessary to open the abdomen, when the pupa, its parts, together with the cast off pulmonary pipes, may be clearly seen. An exact account of all the changes of the interior parts is to be found in Swammerdam’s Book of Nature. These changes are best examined by taking the pupa out of the skin, or outside case, when it begins to harden; for as it has not then quite attained the pupa form, and the members are somewhat different from what they will be when in that state, it is more easy to observe When the time approaches that the hidden insect, now in the pupa form within its old covering, is to attain the imago, fly, or perfect state, which generally happens in about eleven days after the preceding change, the superfluous humours are evaporated by insensible perspiration. The little pupa is contracted into the fifth ring of the skin, and the four last rings of the abdomen are filled with air, through the aperture in the respiratory orifice of the tail. This may be seen by exposing the pupa for a short space to the rays of the sun, and then putting its tail in water, when you will find it breathe stronger than it did before, and, by expressing an air bubble out of its tail, and then sucking it in again, will manifestly perform the action of inspiration and expiration. The anterior part of the pupa is drawn back from the skin, and having partly deserted it, with the beak, head, and first ring of the breast, the little creature lies still, until its exhaling members have acquired strength to burst the two membranes which surround it. If the exterior case be opened near this period, a wonderful variety of colour may be perceived through the thin skin which invests the pupa. The colours of many of the different parts are now changed; some parts from aqueous become membranaceous, some fleshy, and others crustaceous. The whole body becomes insensibly shaggy, the feet and claws begin to move: the variations When the fly begins to appear, the exterior skin is seen to move about the third and fourth anterior ring; the insect then uses all its efforts to promote its escape, and to quit the interior and exterior skin at one and the same time. The exterior skin is divided into four parts; the insect immediately afterwards breaks open its inner coat, and casting it off, escapes from the prison in which it was entombed, in the form of a beautiful fly. It is to be observed here, that there is nothing accidental in the breaking of the outermost skin, being perfectly conformable to the rule ordained, always happening in the same manner in all these changes: the skin also is, in those places where it is broke open, so constructed by the Author of nature, as if joined together by sutures. Having now acquired its perfect state, the little creature which lived before in water and mud, enters into a new scene of life, visits the fields and meadows, is transported through the air on its elegant wings, and sports in the wide expanse with unrestrained jollity and freedom. The larva a queue de rat,[76] musca pendula, Lin. is also transformed under the skin, which hardens, and forms a case or general covering to the pupa: two horns are pushed out, while it is in this state, from the interior parts; they serve the purpose of respiration: this larva will be more particularly described in a subsequent part of this chapter. [76] Reaum. 8vo. edit. tom. 4, pt. 2, 11 mem. p. 199, plate 30 and 31. According to Reaumur, the insects in this class, that is, those that pass into the pupa state under the skin of the larva, go through a change more than the caterpillar, a transformation taking place while under their skin, before they assume the pupa form. The aquatic larva of the musca chamÆleon retains its form to the last; but there are many insects that are transformed under their skin, which forms a cone or case for the pupa. In these the larva loses first its length; the body becoming shorter, assumes the figure of an egg; and the skin forms a hard and crustaceous case or solid lodging for the embryo insect. OF THE LIBELLULA OR DRAGON FLY.In the libellula we have an instance of those insects which are termed in the pupa state, semicompleta, that is, such as proceed from the egg in the figure which they preserve till the time arrives for assuming their wings; and who walk, act, and eat as well before that period as afterwards. Of all the flies which adorn or diversify the face of nature, there are few, if any, more beautiful than the libellulÆ: they are almost of all colours, green, blue, crimson, scarlet, and white; some unite a variety of the most vivid teints, and exhibit in one animal more different shades than are to be found in the rainbow. It is not to colour alone that their beauty is confined, it is heightened by the brilliancy of their eyes, and the delicate texture and wide expansion of their wings. The larva of the libellula is an inhabitant of the water, the fly itself is generally found hovering on the borders thereof. These insects are produced from an egg, which is deposited in the water by the parent; the egg sinks to the bottom, and remains there till the young insect finds strength to break the shell. The larva is hexapode, and is not quite so long as the fly; on the trunk are four prominences or little bunches, which become more apparent, in proportion as the larva increases in size and changes its skin. These bunches contain the rudiments of the wings, which adorn the insect when in its perfect state. The head of the larva is exceedingly singular, the whole fore part of it being covered with a mask, which fits it more exactly than the common mask does the human face, having proper cavities within to suit the different prominences of the face; it is of a triangular form, growing smaller towards the bottom; at this part there is a knuckle which fits a cavity near the neck, on this it turns as on a pivot. The upper part of this mask is divided into two pieces or shutters, which the insect can open or close at pleasure; it can also let down the whole mask whenever it pleases. The edges of the shutters are jagged like a saw. It makes use of the mask to seize and hold its prey. There is a considerable difference in the shape of these masks in different species of the libellula, some having two claws near the top of it, which they can thrust out or draw in, as most convenient; these render it a very formidable instrument to the insects on which they feed. These animals generally live and feed at the bottom of the water, swimming only occasionally: their manner of swimming, or rather moving in the water, is curious, being by sudden jerks given at intervals; but this motion is not occasioned by their legs, which at this time are kept immoveable and close to the body; it is by forcing out a stream of water from the tail that the body is carried forward; this may be easily perceived, by The pupa differs but very little from the larva, the bunches containing the wings grow large, and begin to appear like four short thick wings. It is full as lively as the larva, seeking and enjoying its food in the same manner: when it is arrived at its full growth, and is nearly ready to go through its last change, it approaches the edge of the water, or comes entirely out of it, fixing itself firmly to some piece of wood or other substance, by its acute claws. It remains for some time immoveable; the skin then opens down the back, and on the head; through this opening is exhibited the real head and eyes, and at length the legs; it then creeps gradually forward, drawing its wings, and then the body out of the skin. The wings, which are moist and folded, now expand themselves to their real size; the body is also extended till it has gained its proper dimensions, which extension is accomplished by the propelling force of the circulating fluids. When the wings and limbs are dry, it enters on a more noble state of life: in this new scene it enjoys itself to the fullest extent, feasts on the living fragrance issuing from innumerable openings, sports and revels in delight, and, having laid the foundation for its future progeny, sinks into an easy dissolution. The dragon fly is of a ferocious and warlike disposition, hovering in the air like a bird of prey, in order to feed on and destroy The female of the CYNIPS or GALL INSECT, which has no wings, passes through no transformation; while the male, which has four wings, passes through the pupa state before it becomes a fly. The only change, though a considerable one, which takes place in the female gall insect, is this, that after a certain time it fixes itself to the branch of a tree, without being able to detach itself; it afterwards increases much in size, and becomes like a true gall; the female, by remaining thus fixed for the greater part of her life, to the place where she was first seen, has very little the appearance of an animal; it is in this period of their life that they grow most and produce their young, while they appear a portion of the branch they adhere to; and what is more singular, the larger they grow, the less they appear like animals, and whilst they are employed in laying thousands of eggs, seem to be nothing but mere galls. The genera of gall insects are very extensive; they are to be found on almost every shrub and tree. The APHIDES or PLANT LICE, to arrive at their respective state, pass through that of the semicomplete pupa, and their wings do not appear till they have quitted their pupa state; but as in all the families of the pucerons there are many which never become winged, we must not forget to observe, that these undergo no transformation, remaining always the same, without changing their figure, though they increase in size and change their skin. It is remarkable, that amongst insects of the same kind, some individuals should be transformed, while others are Reaumur[77] has shewn that the SPIDER FLY, hyppobosca equina, Lin. lays so large an egg, that the fly which proceeds from it is as big as the mother, though the egg does not increase the least in size from the time it is first laid. The insect proceeds also from the egg in the imago or fly state; it is probably transformed in the egg, for Reaumur has found it in the pupa state therein, and having boiled some of their eggs which had been laid for some days, he found the insect in the form of an oval ball, similar to that in which the pupa of flies with two wings are generally found. De Geer is of opinion that the egg itself is a true larva, which, when it is born, has only to disengage its limbs, &c. from the shell which covers it; and he thinks this the more probable, because there is no embryo seen in this egg, but it is entirely filled with the insect; he has also perceived a contracting and dilating motion in the egg, while it was in the belly of the mother, and immediately after it was laid; circumstances which do not agree with a simple egg. [77] Reaumur, tom. 6, mem. 14. As M. Bonnet[78] has attempted to give a theory of these various changes, the following extract from it will, I hope, prove agreeable to the reader; it will at least tend to render his ideas of this wonderful subject clearer, and will probably open to his mind many new sources of contemplation. [78] Bonnet Considerations sur les Corps organises. Contemplation of Nature, &c. An insect that must cast off its exuvia, or moult five times before it attains the pupa state, may be considered as composed of five organized bodies, inclosed within each other, and nourished The first use that some caterpillars which live on leaves make of their new form, is to devour greedily their exuvia: sometimes they do not wait till their jaws have acquired their full strength; some have been seen to gnaw the shell from which they proceeded, and even the eggs of such caterpillars as have not been hatched. When we have once formed the idea that all the exterior parts are inlaid, or included one within the other, the production of new organs does not appear so embarrassing, being nothing more than a simple developement; but it is more difficult to form any conception of the changes that happen in the viscera before and after the transformation, the various modifications they undergo eluding our researches. We have already observed, that a little before the change the caterpillar rejects the membrane that lines the intestinal bag: this bowel has hitherto digested only gross food, whereas it must hereafter digest that which is very delicate: a fluid that circulates in the caterpillar from the hind part towards the head, circulates a contrary way after transformation. Now if this inversion is as real as observation seems to indicate, how amazing the change the interior parts of the animal must have undergone? When the caterpillar moults, small clusters of the tracheal vessels are cast off with the exuvia, and new ones are substituted in their room; but how is this effected, and how are the lungs replaced by other lungs? The more we endeavour to investigate this subject, the more we find it is enveloped in darkness. Whilst the powers of life are employed conformable to the laws of Divine Providence, to change the viscera, and give them a new form, they are also unfolding divers other organs, which were useless to the insect while in the larva state, but which are necessary to that which succeeds. That these interior operations of life may be carried on with greater energy, the animal is thrown into a kind of sleep; during this period, the corpus crassum is distributed into all the parts, in order to bring them to perfection, while the evaporation of the superfluous humours makes way for the elements of the fibres to approach each other, and unite more closely. The little wounds in the inside, which have been occasioned by the rupture of the vessels, are gradually When these various changes are considered, we are surprized at the singularity of the means the Author of nature has made choice of, in order to bring the different species of animals to perfection; and are apt to ask, why the caterpillar was not born a moth? why it passes through the larva and pupa state? why all insects that are transformed do not undergo the same change? These, and a variety of questions that may be started concerning the constituent substances of those existences which appear before us, derive their solution from the general system which is unknown to us. If all were to arrive at perfection at once, the chain would be broken, the creature unhappy, and man most of all. Let us also consider what riches we should have been deprived of, if the silk-worm had been born in its perfect state. Amongst insects, some are produced in the state in which they will remain during their whole lives; others come forth inclosed in an egg, and are hatched from this into a form that admits of no variation; many come into the world under a form which differs but little from that which they have when arrived at an age of maturity; some again assume various forms, more or less remote from that which constitutes their perfect state; lastly, some go through part of these transformations in the body of the parent, and are born of an equal size with them. By these various changes, a single individual unites within itself two or three different species, and becomes successively the inhabitant of two or three worlds: and how great is the diversity of its operation in these various abodes! Since it has been shewn that the larva or caterpillar is really the moth, crawling, eating, and spinning, under the form of the worm, and that the pupa is only the moth swathed up, it is clear that they are not three beings, but that the same individual feels, tastes, sees, and acts by different organs, at different periods of its life, having sensations and wants at one time, which it has not at another; these always bearing a relation to the organs which excite them. OF THE RESPIRATION OF INSECTS.As respiration is one of the most important actions in the life of every animal, great pains have been taken by many naturalists to investigate the nature of this action in insects; to prove its existence, and explain in what manner it is carried on. Malpighi, Swammerdam, Reaumur, and Lyonet have discovered in the caterpillar two air-vessels placed the whole length of the insect, these they have called the tracheÆ; they have also shewn that an infinite number of ramifications proceed from these, and are dispersed through the whole body; that the tracheal vessels communicate with particular openings on the skin of the caterpillar, termed spiracula; there are nine of these on each side of the body. These vessels seem calculated for the reception of air; they contain no fluids, are of a cartilaginous nature, and when cut preserve their figure, and exhibit a well-terminated opening. Notwithstanding this discovery, respiration has not been proved to exist in many species of insects, and the mechanism thereof is very obscure in all; nor is the absence of it more surprising in the caterpillar or embryo state of insects, than in that of other animals, where we find that respiration is by no means necessary to existence previous to their birth, though indispensably so afterwards. Reaumur thought that the air entered by the spiracula into the trachea, but was not expelled by the same orifice, and consequently that the respiration of insects was carried on in a manner totally different from that of other animals; that the air was expired through a number of small holes or pores which are to be found in the skin of the caterpillar, after having been conducted to them through the extremities of the finer ramifications of the tracheal vessels; whereas Bonnet, in consequence of a great variety of experiments, supposed that the inspiration and expiration of the air was through the spiracula, and that there was no expiration of air through the pores of the skin. These experiments were made either by plunging the caterpillars into water, or anointing them with fat and greasy substances, some all over, others only partially. The number of small bubbles which are observed to cover the surface of their bodies, when they are immerged in water, does not arise from the air which is included within, and then proceeding from them, but they are formed by the air which is lodged near the surface of their bodies, in the same manner that it is about all other substances. To render the experiments more accurate, and prevent the air from adhering to the skin, before he plunged the caterpillars in water he always brushed them over with an hair pencil; after this, very few air bubbles were found on their bodies when immerged in water. Caterpillars will remain a considerable time under water, without destroying the principle of life; and they also recover, in general, soon after they are taken out. To know whether a few only of the spiracula might not be sufficient for the purposes of respiration, he plunged some partially in water, so that only two or more spiracula remained in the open air: in these cases the caterpillar did not become torpid as it did when they were all immerged in water. One caterpillar, upon which Bonnet made his experiments, lived eight days suspended in water, with only two [79] Philos. Trans. vol. xlv. p. 300. [80] Lesser Theologie des Insectes, tom. 1, p. 124. Ibid. p. 126. Supposing respiration to be absolutely necessary to the existence of the pupÆ of different insects, when we reflect on the great solidity of their cases or cones, it is not easy to conceive how they can live several months under the earth, in spaces so confined, and almost impervious to the air: and indeed if they did respire, the same situation seems to preclude a continuance of the operation, as the air would soon be corrupted, and unfit for the offices of life. As the tracheÆ are divided and subdivided to a prodigious degree of minuteness, it has been conjectured by Though it is difficult to ascertain whether some insects respire, at least at certain periods of their existence, yet there are others to whom the inspiration and expiration of air seems absolutely necessary: there are many aquatic insects which are obliged to keep their tails suspended on the surface of the water for this purpose. To prove this, keep the tail under water, and you will perceive the insect to be agitated and uneasy, and to seek for some opening to expose this part to the air; if it find none, it soon goes to the bottom and dies. Some aquatic beetles resist the trial for a considerable time, while their larvÆ can only support it for a few minutes. There is a circumstance which renders all experiments on this subject with insects doubtful and difficult, namely, the vast tenaciousness of the life principle in the lower orders of animated nature, and its dissemination through their whole frame. Musschenbroeck inclosed the pupa of a moth in a glass tube, very little larger than the moth itself, and of the following figure. Glass tube The end A of the tube was drawn out in a capillary form, the other end was covered with a piece of wet bladder to exclude the air; the capillary end B was then plunged in water, which rose to D. He placed the capillary part of the tube before a microscope, on a small micrometer, in order to observe any motion or change in the situation of the water; as it is evident the expiration or inspiration of air by the insect would make it rise or fall alternately. In the first experiment he observed a small degree of motion at distant intervals, not above two or three times in an hour; in a second experiment on another subject, he could observe no motion at all. He then placed some pupÆ under the receiver of an air-pump, in water which he had previously purged of its air; on exhausting the air from the receiver, he observed one bubble to arise in a part near the tail, and a few near the wings. The pupÆ did not swell under the operation; on the contrary, on letting in the air, it was found to be diminished in a small degree, but in less than a quarter of an hour it recovered its former figure. M. Martinet published at Leyden, in 1753, a dissertation, in which, it is said, he has clearly proved by a number of experiments that the pupÆ of caterpillars and some other insects do not respire. OF RESPIRATION IN THE LARVA OF THE MUSCA PENDULA.Among the insects in which respiration seems to be most clearly proved, are the larvÆ of the musca pendula, Lin. These, while in the worm state, live under water in the mud, to which they affix themselves; the respiration of fresh air in this situation In the body of the larva are two large tracheal vessels; these air-vessels extend from the head to the tail, terminate in the respiring tubes, and receive the air from them. The larva quits the water when the time of its transformation approaches, and enters into the earth, where the skin hardens and forms a case in which the pupa is formed; soon after the change, four tubes or horns are seen projecting from the case: these Reaumur supposes to be organs for communicating air to the interior parts of the insect; they are connected with little bladders which are found filled with air, and by which it is conveyed to the spiracula of the pupa. The larvÆ of gnats, and other small aquatic insects of the same kind, are furnished with small tubes, that play on the surface of the water, and convey the air from thence to the insect. Many other singularities are to be found amongst the aquatic larvÆ. OF THE GENERATION OF INSECTS.One of the greatest mysteries in nature is generation, or that power by which the various species of animals, &c. are propagated, Though insects are, like larger animals, distinguished into male and female, yet in some classes there is a kind of mules, partaking of neither sex, though themselves originating from the conjunction of both: many other particularities relative to the sexes can “Pleraque insectorum genitalia sua intra anum habent abscondita, et penes solitarios, sed nonnulla penem habent bifidum: cancri autem et aranei geminos, quemadmodum nonnulla amphibia, et quod mirandum in loco alieno, ut cancer, sub basi caudÆ. Araneus mas palpos habet clavatos, qui penes sunt, juxta os utrinque unicum, quÆ clavÆ sexum nec speciem distinguunt; et foemina vulvas suas habet in abdomine juxta pectus; heic vero si unquam vere dixeris: res plena timoris amor, si enim procus inauspicato accesserit, foemina ipsum devorat, quod etiam fit, si non statim se retraxerit. Libellula foemina genitale suum sub apice gerit caudÆ, et mas sub pectore, adeo ut cum mas collum foemina forcipe caudÆ arripit, illa caudam suam pectori ejus adplicet, sicque peculiari ratione connexÆ volitent.” Insects are either oviparous or viviparous; or, in other words, the species is perpetuated either by their laying of eggs, or bringing forth their young alive. The former is the more general case; there are but few instances of the latter. Those insects To form a just idea of the ovaries of insects, I could wish the reader to consult the description that Swammerdam has given of that of the queen bee, and to take a view of the elegant figure that accompanies it, a figure that speaks to the eyes, and by them to the imagination. Malpighi has given a description of the ovaries of the silk-worm moth. Reaumur mentions six or seven species of two-winged flies that are viviparous, bringing forth worms, which are afterwards transformed into flies. The womb of one of these is singularly curious; it is formed of a band rolled up in a spiral form, and about two inches and an half in length; so that it is seven or eight times longer than the body of the fly, and composed of worms placed one on the side of the other with wonderful art: they are many thousands in number.[81] [81] Reaumur Mem. des Insectes, tom. 4, p. 415. OF THE APHIDES OR PUCERONS.These are a species of insects that have opened new views of the oeconomy of animated beings; they belong to the hemiptera class. The rostrum is inflected, the antennÆ are longer than the thorax; some have four erect wings, others are entirety without them. Towards the end of the abdomen there are two tubes ejecting that most delicate juice called honey-dew. Various names have been applied to them, the proper one is aphis, that by M. Bonnet had repeated experiments of this kind, as far as the sixth generation, which all uniformly presented the observer with fruitful virgins, when he was engaged in a series of new and tedious experiments, from a suspicion imparted by M. Trembley in a letter to him, who thus expresses himself: “I have formed the design of rearing several generations of solitary pucerons, in order to see if they would all equally bring forth young. In cases so remote from usual circumstances, it is allowed to try all sorts of means; and I argued with myself, Who knows but that one copulation might serve for several generations?” This “WHO KNOWS” persuaded M. Bonnet that he had not sufficiently pursued his investigations. He therefore now reared to the tenth generation his solitary aphides, having the patience to keep an exact account of the days and hours of the birth of each generation. The result of this pursuit was, his discovering both males and females among them, whose amours were not in the least In order to give a further insight into the nature of these insects, I shall insert an extract of a description of their different generations, by Dr. Richardson, as published in the Philosophical Transactions for the year 1771. The great variety of species which occur in the insects now under consideration, may make an inquiry into their particular natures seem not a little perplexing, but by reducing them under their proper genera, the difficulty is considerably diminished. We may reasonably suppose all the insects, comprehended under any distinct genus, to partake of one general nature; and, by diligently examining any particular species, may thence gain some insight into the nature of all the rest. With this view Dr. Richardson chose out of the various sorts of aphides the largest of those found on the rose-tree, not only as its size makes it the more conspicuous, but as there are few others of so long a duration. This sort appears early in the spring, and continues late in the autumn; while several are limited to a much shorter term, in conformity to the different trees and plants from whence they draw their nourishment. If at the beginning of February the weather happen to be so warm, as to make the buds of the rose-tree swell and appear green, small aphides are frequently to be found on them, though In the spring months there appear on the rose-trees but two generations of aphides, including those which proceed immediately from the last year’s eggs; the warmth of the summer adds so much to their fertility, that no less than five generations succeed Early in the month of June, some of the third generation, which were produced about the middle of May, after casting off their last covering, discover four erect wings, much longer than their bodies; and the same is observable in all the succeeding generations which are produced during the summer months, but still without any diversity of sex; for some time before the aphides come to their full growth, it is easy to distinguish which will have wings, by a remarkable fullness of the breast, which in the others is hardly to be distinguished from the body. When the last covering is rejected, the wings, which were before folded up in a very narrow compass, are gradually extended in a surprizing manner, till their dimensions are at last very considerable. The increase of these insects in the summer time is so very great, that by wounding and exhausting the tender shoots, they would frequently suppress all vegetation, had they not many enemies to restrain them. Notwithstanding these insects have a numerous tribe of enemies, they are not without friends, if those may be considered as such, who are officious in their attendance for the good things they expect to reap thereby. The ant and the bee are of this kind, collecting the honey in which the aphides abound, but with this difference, that the ants are constant visitors, the bee only when flowers are scarce; the ants will suck In the autumn three more generations of aphides are produced, two of which generally make their appearance in the month of August, and the third before the middle of September. The two first differ in no respect from those which are found in summer; but the third differs greatly from all the rest. Though all the aphides which have hitherto appeared were females, in this tenth generation several male insects are found, but not by any means so numerous as the females. The females have at first the same appearance with those of the former generations, but in a few days their colour changes from a green to a yellow, which is gradually converted into an orange before they come to their full growth; they differ also in another respect from those which occur in summer, for all these yellow females are without wings. The male insects are, however, still more remarkable, their outward appearance readily distinguishing them from this and all other generations. When first produced, they are not of a green colour like the rest, but of a reddish brown, and have afterwards a dark line along the back; they come to their full growth in about three weeks, and then cast off their last covering, the whole insect being after this of a bright yellow colour, the wings only excepted; but after this change to a deeper yellow, and in a very few hours to a dark brown, if we except the body, which is something lighter coloured, and has a reddish cast. The males no sooner come to maturity than they copulate with the females, who in a day or two after their intercourse with the males lay their eggs, generally near the buds. Where there are a number crowded together, they of course interfere with each other, in which case they The aphides are very injurious to trees and vegetables of almost every kind; the species is so numerous, and all endued with so much fertility, that if they were not destroyed by a numerous host of enemies, the leaves, the branches, and the stem of every plant would be covered with them. On almost every leaf inhabited by aphides, a small worm is to be found, that feeds not upon the leaves, but upon these insects, devouring them with incredible rapacity: Reaumur supplied a single worm with above one-hundred aphides, every one of which it devoured in less than three hours. Indeed myriads of insects seem to be produced for no other purpose than to destroy them. OF THE APIS OR BEE.The bee belongs to the hymenoptera order, the mouth is furnished with two jaws, and a proboscis protected by a double sheath, see Fig. 3. Plate XIII. They have four wings; when these are at rest, the two foremost cover those behind. There is a sting in the tail of the working and female bee. Of the bee kind fifty-five species are enumerated by LinnÆus. Our present observations are confined to the common or domestic bee. In the natural history of insects new objects of surprize are continually rising before the observer: however singular the preceding account of the production of the aphides may appear, that of bees is not less so. This little republic has at all times gained M. Schirach, a German naturalist, affirms that all the common bees are females in disguise, in which the organs that distinguish the sex, and particularly the ovaria, are obliterated, or at least from their extreme minuteness have escaped the observer’s eye; that every one of these bees, in the earlier period of its existence, is capable of becoming a queen bee, if the whole community should think it proper to nurse it in a particular manner, and raise it to that rank: in short, that the queen bee lays only two kinds of eggs, those that are to produce the drones, and those from which the working bees are to proceed. Schirach made his experiments not only in the early spring months, but even as late as November. He cut off from an old hive a piece of the brood-comb, [82] Schirach Histoire Naturelle des Abeilles. Mr. Debraw has carried the subject further, by discovering the impregnation of the eggs by the males, and the difference of the To prove further that the eggs are fecundated by the males, and that their presence is necessary at the time of breeding, Mr. Debraw made the following experiments. They consist in leaving in a hive the queen, with only the common or working bees, without any drones, to see whether the eggs she laid would be prolific. To this end he took a swarm, and shook all the bees into a tub of water, leaving them there till they were quite senseless; by which means he could distinguish the drones without any danger of being stung: he then restored the queen and working bees to their former state, by spreading them on a brown paper in the sun; after this he replaced them in a glass hive, where they soon began to work as usual. The queen laid eggs, which, to his great surprize, were impregnated, for he imagined he had separated all the drones or males, and therefore omitted watching them; at the end of twenty days he found several of his eggs had, in the usual course of changes, produced bees, while some had withered away, and others were covered with honey. Hence he inferred, that some of the males had escaped his notice, and impregnated part of the eggs. To convince himself of this, he took away all the brood-comb that was in the hive, in order to oblige the bees to provide a fresh quantity, being determined to watch narrowly their motions after new eggs should be laid in the cells. On the second day after the eggs were deposited, he perceived the same operation that was mentioned before, namely, that of the bees hanging down in the form of a curtain, while others thrust the posterior part of their bodies into the cells. He then introduced his hand into the hive, broke off a piece of the comb, in which there were two of these insects; he found in neither of them any sting, a circumstance peculiar to the drones; upon dissection, The eggs, after the fourth day, instead of changing in the manner of caterpillars, were found in the same state they were in the first day, except that some were covered with honey. A singular event happened the next day, about noon; all the bees left their own hive, and were seen attempting to get into a neighbouring one, on the stool of which the queen was found dead, being no doubt slain in the engagement. This event seems to have arisen from the great desire of perpetuating their species, and to which end the concurrence of the males seems so absolutely necessary; it made them desert their habitations, where no males were left, in order to fix a residence in a new one, in which there was a good stock of them. To be further satisfied, Mr. Debraw took the brood-comb, which had not been impregnated, and divided it into two parts; one he placed under a glass bell, No. 1, with honey-comb for the bees food, taking care to leave a queen, The editor of the CyclopÆdia says, that the small drones are all dead before the end of May, when the larger species appear, and supersede their use; and that it is not without reason that a modern author suggests, that a small number of drones are reserved to supply the necessities of the ensuing year; but that they are very little, if any, larger than the common bee. It does not enter into our plan to notice further in this place the wonders of this little society. A bee-hive is certainly one of the finest objects that can offer itself to the eyes of the beholder. It is not easy to be weary of contemplating those workshops, where thousands of labourers are constantly engaged in different employments.[83] [83] The remarks made by the late Mr. Hunter on the experiments of Messrs. Schirach and Debraw, in my opinion, merit the attention of the reader; they are contained in his “Observations on Bees,” comprizing a variety of information respecting the history and oeconomy of those curious insects. This ingenious and interesting account is inserted in the Philosophical Transactions for the year 1792, page 128-195. I cannot altogether subscribe to his opinion relative to the minuteness and prolixity of Swammerdam. Edit. OF THE EGGS OF INSECTS.The eggs are contained and arranged in the body of the insect, in vessels which vary in number and figure in different species; the same variety is found in the eggs themselves: some are round, others oval, some cylindrical, and others nearly square; the shells of some are hard and smooth, while others are soft and flexible. It is a general rule, that eggs do not increase in size after they are laid; among insects, we find however an exception to this; the eggs of the tenthredo of LinnÆus increase after they are laid, but their shell is soft and membranaceous. The eggs of insects differ in their colours; some may be found of almost every shade, of yellow, green, brown, and even black. The eggs of the lion puceron,[84] hemerobius, Lin. are very singular objects, and cannot have escaped the eye of any person who is conversant among the insects which live on trees; though of the many who have seen them, few, if any, have found what they really were. It is common to see on the leaves and pedicles of the leaves of the plumb-tree, and several other trees, as also on their young branches, a number of long and slender filaments, running out to about an inch in length; ten or twelve of these are usually seen placed near one another, and a vast number of these clusters are found on the same tree; each of these filaments is terminated by a sort of swelling or tubercle of the shape of an egg. They have generally been supposed to be of vegetable origin, and that they were a sort of parasitical plant growing out of others. There is a time when these egg-like balls are found open at the ends; in this state they very much resemble flowers, and have been figured as such by some authors, though they are only the [84] Reaumur Hist. de Insectes, vol. xi. p. 142. Divine Providence instructs the insects, by a lower species of perception, to deposit their eggs not only in safety from their numerous enemies, but also in situations where a sufficient quantity of food is on the spot to support and nourish the larva immediately on breaking the shell. Some deposit their eggs in the oak leaf, producing there the red gall; others choose the leaf of the poplar, which swells into a red node or bladder; to a similar cause we must attribute the red knob which is often seen on the willow leaf, and the three pointed protuberances upon the termination of the juniper branches. The leaves of the veronica and cerastium are drawn into a globular head by the eggs of an insect lodged therein. The phalÆna neustria glues its eggs with great symmetry and propriety round the smaller branches of trees. Fig. 1. Plate X. represents a magnified view of the nest of eggs taken off the tree after the caterpillar had eaten its way through them; the strong ground-work of gum, by which they are connected and bound together, is very visible in many places; they strengthen this connection further, by filling up all the intervening space between the eggs with a very tenacious substance. These eggs are crustaceous, and similar to those of the hen; Fig. 2 represents the natural size. Fig. 3 is a magnified vertical section of the eggs, shewing their oval shape; Fig. 4 the natural size. Fig. 5 is an horizontal section through the middle of the egg, and Fig. 6 the same not magnified. It is not easy to describe the beauty of these objects, when viewed in the lucernal microscope; the regularity with which they are placed, the delicacy In the Lapland Alps there is a fly covered with a downy hair, called the rhen-deer gad-fly, oestrus tarandi, Linn. it hovers all day over these animals, whose legs tremble under them; they prick up their ears, and flee to the mountains covered with ice and snow to escape from a little hovering fly, but generally in vain, for the insect but too soon finds an opportunity to lodge its egg in the back of the deer; the worm hatched from this egg perforates the skin, and remains under it during the whole winter: in the following year it becomes a fly. The oestrus bovis is an equal terror to oxen; the hippobosca equina, to horses; oestrus ovis,[85] to the sheep, &c. [85] Oestrus ovis in naso sive sinu frontis animalium rumenantium. Linn. The gnat, the ephemera, the phryganea, the libellula, hover over the water all day to drop their eggs, which are hatched in the water, and continue there all the time they are in the larva form. The mass formed by the gnat resembles a little vessel set afloat by the insect; each egg is in the form of a keel, these are curiously connected together. The gnat lays but one egg at a time, which she deposits on the water in a very ingenious and simple manner; she stretches her legs out, and crosses them, thus forming an angle to receive and hold the first egg; a second egg is soon placed next the first; then a third, and so on, till the base is capable of supporting itself; these, as they come to maturity, sink deeper. The spawn of this insect is sometimes above an inch long, and one-eighth of an inch in diameter, and tied by a little stem or stalk to some stick or stone. Sometimes they are laid in a single, sometimes in a double spiral line; sometimes [86] Lessers Theologie des Insectes, tom. 1, p. 143. The fecundity of insects exceeds in an astonishing degree that of all the productions of nature; the vegetables which cover the surface of the earth bear no proportion to their multitudes, every plant supporting a number often of scarce perceptible creatures: of the fatal effects of their prodigious multiplication, our fruit trees, &c. are too frequently a deplorable testimony. On the continent whole provinces sometimes languish in consequence of the dreadful havoc made by them. Reaumur calculated the fecundity of the queen bee as follows: he found that she laid in the two months of March and April 12,000 eggs, so that the swarm which left the hive in May consisted of near 12,000 bees, all produced from one mother: but this calculation falls short of that which was made by Leeuwenhoek on a fly, whose larva feeds on flesh, putrid carcases, &c. which multiply prodigiously, and that in a short space of time. One of these laid 144 eggs, from which he got as many flies in the first month; so that, supposing one-half of these to be females, in the third month we shall have 746,496, all produced in three months from one fly. The following is an experiment of M. Lyonet on the generation of a moth which comes from the chenille a brosse: out of a brood of 350 eggs, produced by a single moth of this kind, he took 80, from which he obtained, when they were arrived at OF THE FOOD OF INSECTS.There are few, if any, productions either of the animal or vegetable kingdoms, which do not supply some kind of insect with food. They may, therefore, be considered under two heads, those Among those which feed on vegetables, some sink themselves in the earth, and by destroying the roots of the plants, do considerable injuries to our gardens. The food of others is dry and hard; they pierce the wood, reduce it to powder, and then feed on it; some, as the cossus, attack and destroy the trees, while the food of others more delicate is the leaves. The leaf is eaten in a different manner by different insects; some eat the whole substance, while others feed only on the parenchymous parts, which are contained between its superficial membranes, forming withinside the leaf paths and galleries. These insects are not always content with the leaf, but attack the flower also: even this food is too gross for many; the bee, the butterfly, the moth, as well as several species of flies, feed only on the honey, or finer juices, which they collect from flowers. We are continually finding the larva of some insect in pears, plumbs, peaches, and other fruit; these unwelcome intruders on the produce of human industry divide fruits, grain, and corn with us, often depriving us of large quantities. There is, indeed, no part of a plant which does not serve as food to different insects; some have one kind of plant marked out for them to inhabit and feed on, others have another assigned to them, on which, and no other, they will feed; each has its appropriate food, and though the parent animal eats not at all, or lives upon food entirely different, yet she is guided, as has before been observed, to deposit her eggs on that peculiar shrub or plant that will be food for her young; while some, more voracious than the rest, feed upon all with equal avidity; but in [87] Select Dissertations from the Amoenitates AcademicÆ, vol. I, p. 398. A great number of insects reject vegetable, and live on animal food; some seeking that which is beginning to putrefy, while others delight in food entirely putrid; others again are nourished by the most filthy puddles, and disgusting excrements; some attack and feed on man himself, while others are nourished by his provision, his cloaths, his furniture: some prey upon insects of another species; others, again, attack their own, and harrass each other with perpetual carnage. Reaumur informs us, that those insects which feed upon dead carcases never attack living animals; the flesh-fly deposits her eggs in the bodies of dead animals, where her progeny receive that nourishment best adapted for them; but this fly never attempts to lay her eggs in the flesh of sound and living animals. Every animal has its appropriate lice, which feed on and infest it. M. Rhedi has given an accurate account of a great number of these little noxious creatures accompanied with figures; but, as if it were not sufficient that these creatures should dwell and live on the external part of the body, and suck the blood of the animal that they infest, we find another species of insects seeking their food in the more vital parts, and feeding on the flesh of the animal, while full of life and health. Reaumur has given an history of a fly, oestrus bovis, the larva of which lives upon the backs, and feeds on the flesh of young oxen and cows, where it produces a kind of tumor. The fly lodges its eggs in the flesh, by making a number of little wounds, in each of which it deposits eggs, so that every wound becomes a nest, the eggs of which are hatched by the heat of the animal. Here the larvÆ find abundant food, at the same time that they are protected from the changes of the weather; and here they stay till they are fit for transformation. The parts they inhabit are often easy to be discovered by a kind of lump or tumor, which they form by their ravages; this tumor suppurates, and is filled with matter; on this disgusting substance the larvÆ feed, and their heads are always found plunged in it.[88] [88] The obscure and singular habitations of the British oestri are the stomach and intestines of the horse, the frontal and maxillary sinuses of sheep, and beneath the skin of the backs of horned cattle. In other parts of the world they inhabit various other animals. The larva of the oestrus bovis lives beneath the skin of horned cattle, between it and the cellular membrane, in a proper sack or abcess, which is rather larger than the insect, and by narrowing upwards opens externally to the air by a small aperture. When arrived at its full growth, it effects its escape from the abcess by pressing against the external opening; when the opening has thus obtained the size of a small pea, the larva writhes itself through, and falls from the back of the animal to the ground; and, seeking a convenient retreat, becomes a chrysalis, in which state it continues from about the latter end of June to about the middle of August; the perfect insect, on leaving the chrysalis, forces open a very remarkable marginated triangular lid or operculum. The oestrus in its perfect or fly state is the largest of the European species of this genus, and is very beautiful. Although its effects on the cattle have been so often remarked, yet the fly itself is rarely seen or taken, as the attempt would be attended with considerable danger. The pain it inflicts in depositing its egg is much more severe than in any of the other species: when one of the cattle is attacked by this fly, it is easily known by the extreme terror and agitation of the whole herd; the unfortunate object of the attack runs bellowing from among them to some distant part of the heath, or the nearest water, while the tail, from the severity of the pain, is held with a tremulous motion straight from the body, in the direction of the spine, and the head and neck are also stretched out to the utmost. The rest, from fear, generally follow to the water, and disperse to different parts of the field. The larvÆ of this insect are mostly known among the country people by the name of wornuls, wormuls, or warbles, or more properly bots. The larva of the oestrus equi is very commonly found in the stomach of horses. These larvÆ attach themselves to every part of the stomach, but are generally most numerous about the pylorus; and are sometimes found in the intestines. They hang most commonly in clusters, being fixed by the small end to the inner membrane of the stomach, to which they adhere by two small hooks or tentacula. The larvÆ having attained their full growth in about a month, on dropping to the ground find some convenient retreat, change to the chrysalis, and in about six or seven weeks the fly appears. The larva of the oestrus hÆmorrhoidalis resembles in almost every respect that of the oestrus equi, and occupies the same situation in the stomach of the horse. When it is ripe, and has passed through the intestines and the sphincter ani it assumes the chrysalis state in about two days, and in about two months the fly appears. The generally received opinion has been that the female fly enters the anus of the horse to deposit its eggs, and Reaumur relates this circumstance on the authority of Dr. Gaspari; from the account of its getting beneath the tail, it is probable that the fly he saw was the hippobosca equina, which frequently does this: its getting within the rectum appears to have been additional. That a fly might deposit its eggs on the verge of the anus is not impossible, but we know no instance of it: the fact is, that the part chosen by the oestrus hÆmorrhoidalis for this purpose is the lips of the horse, which is very distressing to the animal from the excessive titillation it occasions; for he immediately after rubs his mouth against the ground, his fore legs, or sometimes against a tree, or if two are standing together, they often rub themselves against each other. At the sight of this fly, the horse appears much agitated, and moves its head backward and forward in the air to baulk its touch, and prevent its darting on the lips; but the fly, watching for a favourable opportunity, continues to repeat the operation; till at length, the enraged animal endeavours to avoid it by galloping away to a distant part of the field. If still pursued, its last resource is in the water, where the oestrus is never observed to follow him. The oestrus veterinus is by LinnÆus called nasalis, from an idea of its entering the nostrils of the horse to deposit its eggs, which it could not well do without destroying its wings, and is therefore probably as much a fable as the “mire per anum intrans” of the oestrus hÆmorrhoidalis. The oestrus ovis is mostly found in the horns and frontal sinuses of the sheep, though it has been remarked that the membranes lining these cavities were hardly at all inflamed, while those of the maxillary sinuses were highly so; from which it is suspected that they inhabit the maxillary sinuses, and crawl, on the death of the animal, into these situations in the horns and frontal sinuses. When the larvÆ are full-grown they fall through the nostrils, and change to the pupa state, lying on the earth, or adhering by the side to a blade of grass. The fly bursts the shell of the pupa in about two months. The above concise account of the different oestri is extracted from the excellent paper on the subject by Mr. B. Clark, F. L. S. For his more ample description, accompanied with coloured figures of the several British species, see Transactions of the Linnean Society, vol. iii. page 283-329, just published. Edit. Neither the larva, pupa, or even the egg-state of some insects are exempt from the attacks of others, who deposit their eggs in them; these, after having passed through the usual transformations, become what is termed the ichneumon fly. The following are the curious observations of an ingenious naturalist on this fly. “As I was observing,” says he, “one day some caterpillars which were feeding voluptuously on a cabbage leaf, my attention was attracted to part of the plant, about which a little fly was buzzing on its wing, as if deliberating where to settle: I was surprized to see the herd of caterpillars, creatures of twenty times its size, endeavouring in an uncouth manner, by various contortions [89] Inspector, No. 64. [90] “The genus of insects called ichneumon derive their support and nourishment from other insects, some depositing their eggs in the larva, others again in the pupa, and some even in the ovum or egg itself, the contents of which, minute as they are, are sufficient to support the young larvÆ until their change into their pupa state. Some deposit only one egg in a place, as the ichneumon ovulorum, and others again a great number, as ichneumon puparum, &c. but whether the egg be placed in the pupa, larva, or ovum, the destruction of the foster parent is inevitable. The larvÆ of large moths or butterflies that have been wounded by an ichneumon, live and feed, though with evident marks of disease, until those parasites are full fed, and able to change into their second or pupa state.” See Observations on the Œconomy of the Ichneumon Manifestator, in the Transactions of the Linnean Society, vol. 3, p. 23 & seq. by T. Marsham, Esq. Sec. L. S. Edit. Of this strange scene it is difficult for us to form a proper judgment; we are unacquainted with the organs of the caterpillar, Lastly, the number of insects which feed upon others, nay, some even upon their own species, is very great: it is among these that we find the traces of the greatest art and cunning, as well in attack as defence; some indeed use main force alone. Most persons are acquainted with the dexterous arts of the spider, the curious construction of the web he spins, and the central position he takes, in order to watch more effectually the least motion that may be communicated to its tender net. Those who wish to pursue this subject further, will find ample satisfaction by consulting the works of Reaumur and De Geer. OF THE HABITATION OF INSECTS.Insects may be divided, with respect to their habitations, into two classes, aquatic and terrestrial. Stagnant waters are generally filled with insects, who live therein in different manners. These are, 1. Aquatic insects which remain always on the superficies of the water, or which at least plunge themselves therein but rarely. 2. Others that live only in the water, and cannot subsist out of it. 3. Many, after having lived in the water while in the larva and pupa state, quit it afterwards with wings, and become entirely terrestrial. 4. Some undergo all their transformations in the water, and then become amphibious. 5. Others again are born and grow in the water, but undergo their pupa state on dry land, and after they are arrived at their perfect state, live equally in air and water; and 6. There are some who live at the same time part in the water and part on land, but after their transformation cease to be aquatic. Among the insects which remain on the superficies of the water, are some spiders, which run with great address and agility, without moistening their feet or their body; when they repose themselves, they extend their feet as much as possible. There are also aquatic bugs, which swim, or rather run on the water with great velocity, and by troops; another bug walks very slowly on the water; the gyrinus moves very swiftly, and in circles. There is a species of podura[91] which live in society, and are often accumulated together in little black lumps. Those insects which always live in the water are generally born with the [91] De Geer Discours sur les Insectes, tom. 2, p. 103. Those insects which, after having lived in the water, leave it when in a winged state, are very numerous: among these we may reckon the libellula, the ephemera, the phryganea, culices, tipulÆ, and some species of muscÆ. All these, when in the larva and pupa state, live in the water; but when they have assumed their perfect form, are entirely terrestrial, and would perish in their former element. The notonecta, the nepa or aquatic scorpion, &c. never quit the water till they have passed through all their transformations, when they become amphibious, generally quitting it in the evening. The water-beetles, of which there are many species, remain in the water all day, but toward evening come upon the ground and fly about, then plunge themselves again in the water at the approach of the rising sun. The larvÆ of these insects are entirely aquatic, but when the time of their pupa state arrives, they take to the earth, where they make a spherical case; so that these insects are aquatic in the larva, terrestrial in the pupa, and amphibious in the imago state. We find an instance of an insect that lives at the same time in the water and the air, in the singular larva described by Reaumur, Memoires de l’Acad. in 1714, p. 203. It has the head and tail in the water, while the rest of the body is continually kept above the surface. In order to support itself in this singular position, it bends the body, bringing the head near the tail, raising the rest above the water, and supporting itself against some fixed object, as a plant, or against the borders of the pond; or, if it be placed At the baths of Abano, a small town in the Venetian state, there is a multitude of springs, strongly impregnated with sulphur, and of a boiling heat. In the midst of these boiling springs, within three feet of four or five of them, there is a tepid one about blood-warm. In this water, not only the common potamogetons and confervas, or pond-weeds and water-mosses are found growing in an healthy state, but numbers of small black water beetles are seen swimming about, which die on being taken out and plunged suddenly into cold water.[92] [92] Jones’s Physiological Disquisitions, p. 171. Many insects that live under the surface of the earth crawl out on certain occasions, as the julus, scolopendra, and the oniscus; they are often also to be found under stones, or pieces of rotten wood. Some insects remain under ground part of their life, but quit that situation after their change; as do some caterpillars, many of the coleoptera class, &c. There are some species of spiders, which form habitations in sand; one of which makes a hole in the sand, lining it with a kind of silk, to prevent its crumbling away; this spider generally keeps on the watch near the mouth of the hole, and, if a fly approach, runs at it with such velocity, as seldom to fail in its attempt of seizing the little animal, which is immediately conveyed to the den of the spider. The formica-leo, or ant-lion, also inhabits sand.[93] [93] The art and dexterity with which the formica-leo entraps ants, as well as other insects, merits notice; he makes a pit in fine dry sand, shaped like a funnel or an inverted cone, at the point or reverted apex of which he takes his station, concealing every part of his body except the tips of his two horns; these are expanded to the two sides of the pit. When an insect treads on the edge of this precipice, it perhaps slides into it; if not, its steps remove a little of the sand, which of course descends down the sides, and gives the enemy notice of his prey. He then throws up the sand with which his head is covered, to involve the insect, and bring it to the bottom with the returning force of the sand: this, by repeated efforts he is sure to effect, as all the attempts of the unfortunate victim to escape, when once within the verge of the pit, are in vain. One species of the formica-leo forms no pit to entrap its prey, but seizes it by main force. Edit. Another spider, discovered by M. l’Abbe Sauvage,[94] burrows in the earth like a rabbit, making a hole one or two feet deep, of a regular diameter, and sufficiently large to move itself with ease. It lines the whole of it, either to keep the ground from tumbling in, or in order to perceive more regularly at the bottom what happens at the mouth, at which it forms a kind of door, made of different layers of earth, connected together by threads and covered with a strong web of a close texture; the threads are prolonged on one side, and fixed to the ground, so as to form a strong joint; the door is hung in such a manner, as always to fall by its own gravity. One of these cases or nests is in her Majesty’s cabinet at Kew. [94] Histoire de l’Acad. 1758, p. 26. The several parts of trees and plants afford a variety of habitations for insects, where they find an abundance of food. They dwell, l. in the roots; 2. in the wood; 3. in the leaves, and in the galls which grow upon them and the branches; 4. in the flowers; 5. in the fruits and grains. To enumerate the various species of these inhabitants would be endless; many particulars have been already noticed; it has also appeared that some inhabit the most foetid substances they can find, while others dwell with and live on the larger animals; so that it only remains just to Among the solitary bees there are so many curious circumstances to be described, that a single volume would not suffice to contain the particulars; we shall here only relate such as concern their habitations. One of these forms its nest under ground, which is composed of several cells artfully let into each other, but not covered with a common inclosure; each cell consists of two or three membranes, inexpressibly fine, and placed over each other. The cavity, in which the nest is placed, is smeared over with a layer of matter, like that of which the cells are formed, and apparently similar to the viscous humour which snails spread in their passage from one place to another, and it is probable that they are formed of the same materials; this substance, though of so delicate a nature, gives them such a degree of consistency, that they may be handled without altering their form. An egg is deposited at the bottom of each cell, where, after it is hatched, the worm finds itself in the midst of a plentiful stock of provision; for in each cell there is placed a quantity of paste, or a kind of wax, which is to serve as food for the worm, and support the wall of the cell. The worm is also instructed so to conduct itself, and eat this food, as to leave sufficient props for supporting the walls of its apartment. Many species of these bees content themselves with penetrating into the earth, scooping out hollow cavities therein, polishing the walls, then depositing an egg and a sufficient quantity of provisions. There is another species, that forms its nest under ground with remarkable industry; this bee generally makes a perpendicular hole in the earth about three inches deep, and cylindrical, till within about three-fourths of an inch of the bottom, when it begins to enlarge; as soon as the bee has given it the suitable [95] Reaumur Memoires pour l’Histoire des Insectes, edit. 8vo. tom. 6, partie 1, p. 170. The mason bee is so called by Reaumur from the manner of its building its nest. These bees collect with their jaws small parcels of earth and sand, which they glue together with a strong cement furnished from the proboscis; and of this they form a simple but commodious habitation, which is generally placed Another species of the solitary bee (apis centuncularis, Linn.) constructs her nest in pieces of rotten wood, and has therefore been called the carpenter bee.[96] She divides it into stages, disposing them sometimes in three rows, with partitions curiously left between each; in these she deposits her eggs, with the food necessary for the young ones when hatched. They separate the wood in a very expeditious manner, by dividing its ligneous fibres or threads, till they have made a proper sized hole. [96] Geoffroy Hist. abregee des Insectes, tom. 2, p. 401. The art and sagacity displayed by another bee,[97] whose nest is constructed of single pieces of leaves, is truly wonderful. The nest itself is cylindrical, formed of several cells, placed one within [97] Reaumur Memoires pour l’Histoire des Insectes, tom. 6, par. 1, p. 122. The proceedings of the mason ichneumon wasp,[98] sphex, Linn. are totally different from those of the common wasp, though equally curious. It generally begins its work in May, and continues it for the greatest part of June. The true object of her labour seems to be the digging of a hole a few inches deep in the ground; yet in the constructing of this, she forms a hollow tube above ground, the base of which is the aperture of the hole, and which is raised as high above ground as the hole is deep below; it is formed with a great deal of care, resembling a gross kind of fillagree work, consisting of the sand drawn from the hole. The sand out of which she excavates her cell, is nearly as hard as a common stone; this it readily softens with a penetrating liquor with which she is well provided; a drop or two of it is imbibed immediately by the sand on which it falls, which is instantly rendered so soft, that she can separate and knead it with her teeth and fore feet, forming it into a small ball, which she places on the edge of the hole as the foundation stone of the pillar she [98] Reaumur Mem. pour l’Histoire des Insectes, tom. xi. par. 2, p. 9. From a retrospect view of this chapter, we may observe a striking difference between man and the lower orders of animal creation. Man is born totally ignorant; so much so, that he has no knowledge even of the mother’s breast, till he has been brought acquainted with it by repeated trials; he has no innate ideas, is unable to choose what is proper for his food; he cannot form his voice to any articulate pronunciation, or to express the affections of love; whereas the quadruped, the bird, and the insect, are born to all that knowledge which is necessary for the gratification of those desires or that love which forms their life; and, consequently, in the knowledge of every thing relating to their well-being, their food, their habitations, the commerce of the sexes, their provision for their young, &c. from the impulse of the pleasure arising from these innate desires and affections, the larva is also prompted to seek and aspire after a change of its earthly state. If it were not foreign to the subject in hand, it might be easy to shew, by a variety of reasons, that this imperfection of man at his nativity constitutes his real perfection, and places him infinitely, if I may so speak, above the brute creation; for man is not created relatively perfect, but formed a recipient of all perfection. OF THE TERMITES, GENERALLY CALLED WHITE ANTS.As no insects exceed the termites in their wonderful oeconomy, wise contrivances, and stupendous buildings, it will be proper to give the reader some account of them; which I am enabled to do from the excellent paper written by the late Mr. Smeathman, and published in the Philosophical Transactions for the year 1781, part 1. The termites are represented by LinnÆus as the greatest plagues of both Indies, and are indeed justly deemed so every where These insects have been noticed by various travellers in different parts of the torrid zone; where numerous, as is the case with all equinoctial continents, and islands not fully cultivated, many persons have been excited by curiosity to observe them; and, indeed, those devoid of that disposition must have been very fortunate, if, after a short residence, they were not compelled to pay them attention for the preservation of their property. They make their approaches chiefly under ground, descending below the foundations of houses and stores, at several feet from the surface, and rising again either in the floors, or entering at the bottoms of the posts of which the sides of the buildings are composed, boring quite through them, following the course of the fibres to the top, or making lateral perforations and cavities here and there as they proceed. While some are employed in gutting the posts, others ascend from them, entering a rafter, or some other part of the roof. If they once find the thatch, which seems to be a favourite food, they soon bring up wet clay, and build their pipes or galleries through the roof in various directions, as long as it will support them; sometimes eating the palm-tree leaves and branches of which it is composed, and perhaps, for variety seems very pleasing to them, the rattan, or other running plant, which is used as a cord to tie the various parts of the roof together, and that to the posts which support it. Thus, with the assistance of the rats, who during the rainy season are apt to shelter themselves there, and to burrow through it, they very soon ruin the house, by These insects are not less expeditious in destroying the shelves, wainscotting, and other fixtures of an house, than the house itself. They are continually piercing and boring in all directions, and sometimes go out of the broadside of one post into that of another adjoining to it; but they prefer and always destroy the softer substances the first, and are particularly fond of pine and fir boards, which they excavate and carry away with wonderful dispatch and astonishing cunning; for, except a shelf has something standing upon it, as a book, or any thing else which may tempt them, they will not perforate the surface, but artfully preserve it quite whole, and eat away all the inside, except a few fibres which barely keep the two sides connected together; so that a piece of an inch-board, which appears solid to the eye, will not weigh much more than two sheets of pasteboard of equal dimensions, after these animals have been a little while in possession of it. In short, the termites are so insidious in their attacks, that we cannot be too much upon our guard against them: they will sometimes begin and raise their works, especially in new houses, through the floor. If you destroy the work so begun, and make a fire upon the spot, the next night they will attempt to rise through another part; and if they happen to emerge under a chest or trunk, early in the night will pierce the bottom, and destroy or spoil every thing in it before the morning. On these accounts the inhabitants set all their chests or boxes upon stones or bricks, so as to leave the bottoms of such furniture some inches above the ground, which not only prevents these insects finding them out so readily, but preserves the bottoms from a corrosive It may be presumed that they have obtained the name of ants from the similarity in their manner of living with those insects, which is in large communities, that erect very extraordinary nests, for the most part on the surface of the ground; from whence their excursions are made through subterraneous passages or covered galleries, which they build whenever necessity obliges, or plunder induces them to march above ground, and at a great distance from their habitations, carry on a business of depredation and destruction scarce credible but to those who have seen it; but, notwithstanding they live in communities, and are, like the ants, omnivorous; though, like them, at a certain period they are furnished with four wings, and emigrate or colonize at the same season, they are by no means the same kind of insects, nor does their form correspond with that of ants in any one state of their existence. The termites resemble the ants, indeed, in their provident and diligent labour, but surpass them, as well as the bees, wasps, beavers, and all other animals, in the art of building, as much as Europeans excel the most uncultivated savages. They shew more substantial instances of ingenuity and industry than any other animals; and do, in fact, lay up vast magazines of provisions and other stores; a degree of prudence which has of late years been denied, perhaps without reason, to the ants. The communities consist of one male and one female, which are generally the common parents of the whole or greater part of the rest, and of three orders of insects, apparently very different The great LinnÆus having seen or heard of but two of these orders, has classed the genus erroneously, for he has placed it among the aptera, or insects without wings; whereas the insect in its perfect state, having four wings without any sting, belongs to the neuroptera; in which class it will constitute a new genus of many species. The different species of this genus resemble each other in form, in their manner of living, and in their good and bad qualities, but differ as much as birds in the manner of building their habitations or nests, and in the choice of the materials of which they compose them. There are some species which build upon the surface of the ground, or part above and part beneath; and one or two species, perhaps more, that build on the stem or branches of trees. There are of every species of termites three orders: 1. The working insects, which for brevity we shall call labourers. 2. The fighters or soldiers, which do not labour; and 3. The winged or perfect insects, which are male and female, and capable of propagation. From these the kings and queens are chosen, and nature has so ordered it, that they emigrate within a few weeks after their elevation to this state, and either establish new kingdoms, or perish within a day or two. Of these, the working insects or labourers are always the most numerous; among that species emphatically called termes bellicosus, which is the largest, there seem to be at the least one-hundred labourers to one of the fighting insects or soldiers. They are in this state about one-fourth of an inch long, and twenty-five of them weigh about a grain, so that they are not so The second order, or soldiers, have a very different appearance from the labourers, and have been by some authors supposed to be the males, and the former neuters; but they are, in fact, the same insects as the foregoing, only they have undergone a change of form, and approached one degree nearer to the perfect state. They are much larger, being half an inch long, and equal in size to fifteen of the labourers. There is now, likewise, a most remarkable circumstance in the form of the head and mouth; for in the former state the mouth is evidently calculated for gnawing and holding bodies; but in this state, the jaws being shaped like two very sharp awls a little jagged, they are incapable of any thing but piercing or wounding, for which purposes they are well calculated, being as hard as a crab’s claw and placed in a strong horny head larger than all the rest of the body together. The insect in its perfect state is varied still more in its form; the head, thorax, and abdomen, differ almost entirely from the same parts in the labourers and soldiers; and, besides this, the animal is now furnished with four fine large brownish transparent wings, with which it is, at the time of emigration, to wing its way in search of a new settlement; in short, it differs so much from its form and appearance in the two other states, that it has never been supposed to be the same animal, but by those who have seen it in the same nest; and some of these have distrusted the evidence of their senses. It was so long before Mr. Smeathman met with them in the nests, that he doubted the information In the winged state, their size as well as form is altered. Their bodies in this state measure between six and seven-tenths of an inch in length, their wings above two inches and an half from tip to tip, and they are equal in bulk to about thirty labourers, or two soldiers. They are furnished with two large eyes placed on each side of the head; if they had any before, they are not easily to be distinguished. In this form the animal comes abroad during or soon after the first tornado, which at the latter end of the dry season proclaims the approach of the ensuing rains, and seldom waits for a second or third shower; if the first, as is generally the case, happen in the night, and bring much wet after it, the quantities that are to be found the next morning all over the surface of the earth, but particularly on the waters, is astonishing; for their wings are only calculated to carry them a few hours; and after the rising of the sun, not one in a thousand is to be found with four wings, unless the morning continues rainy, when here and there a solitary being is seen winging its From one of the most active, industrious, and rapacious; from one of the most fierce and implacable little animals in the world, they are in this state changed into an innocent helpless insect, incapable of making the least resistance to the smallest ant. The ants are to be seen on every side in infinite numbers, of various species and sizes, dragging these annual victims to their different nests. Some are however so fortunate as to escape, and be discovered by the labouring insects that are continually running about the surface of the ground under their covered galleries, the little industrious creatures immediately inclose them in a small chamber of clay, suitable to their size, into which at first they leave but one small entrance, only large enough for themselves and the soldiers to go in and out, but necessity obliges them to make more entrances. The voluntary subjects charge themselves with the task of providing for the offspring of their sovereigns, as well as to work and to fight for them, until they shall have raised a progeny capable at least of dividing the task with them. The business of propagation soon commences; and the labourers having constructed a small wooden nursery, hereafter to be described, carry the eggs and lodge them there as fast as they can obtain them from the queen. About this time a most extraordinary change begins to take place in the queen, to which we know nothing similar, except in the pulex penetrans of LinnÆus, the jigger of the West-Indies, and in the different species of coccus cochineal. The abdomen of this female begins gradually to extend and enlarge to such an enormous size, that an old queen will have it increased so as to be fifteen hundred or two thousand times the bulk of the rest of her body, and twenty or thirty thousand times the bulk of a labourer; the skin between the segments of the abdomen extends in every direction, and at last the segments are removed to half an inch distance from each other, though at first the length of the whole abdomen was not above half an inch. They preserve their dark-brown colour, and the upper part of the abdomen is marked with a regular series of brown bars, from the thorax to the posterior part of the abdomen, while the intervals between them are covered with a thin, delicate, transparent skin, and appear of a fine cream colour, a little shaded by the dark colour of the intestines and watery fluid seen here and there beneath. It is supposed that the animal is upwards of two years old when the abdomen is increased to three inches in length: they have sometimes been found of near twice that size. The abdomen is then of an irregular oblong shape, being contracted by the muscles of every segment, and is become one vast matrix full of eggs, which make long circumvolutions through an innumerable quantity of very minute vessels, that circulate round the inside in a serpentine manner, which would exercise the ingenuity of a skilful anatomist to dissect and develope. This singular matrix is not more remarkable for its amazing extension and size, than for its peristaltic motion, which resembles the undulation of waves, and continues incessantly without any apparent effort of the animal; so that one part or other is alternately rising and sinking in perpetual succession. The matrix seems never at rest, but to be These eggs are instantly taken from her body by her attendants, and carried to the nurseries, which in a great nest may some of them be four or five feet distant in a straight line, and consequently much farther by their winding galleries. Here the young, when they are hatched, are attended and provided with every thing necessary, until they are able to shift for themselves, and take their share of the labours of the community. The termes bellicosus being the largest species, is most remarkable, and best known on the coast of Africa. It erects immense buildings of well-tempered clay or earth, which are contrived and finished with such art and ingenuity, that we are at a loss to say whether they are most to be admired on that account, or for their enormous magnitude and solidity. The reason that the larger termites have been most remarked is obvious; they not only build larger and more curious nests, but are also more numerous and do infinitely more mischief to mankind.[99] [99] It may appear surprizing, that a Being perfectly good should have created animals which seem to serve no other end but to spread destruction and desolation wherever they go. But let us be cautious in suspecting any imperfection in the Father of the universe: what, on a superficial view may seem only productive of mischief, will upon mature deliberation be found worthy of that wisdom which pervades every part of the creation. Many poisons prove valuable medicines; storms are beneficial; and diseases often preserve life, and are conducive to its future enjoyments. The termites, it must be allowed, are frequently pernicious to mankind, but they are also very useful, and even necessary; one valuable purpose which they serve, is, to destroy decayed trees and other substances, which, if left on the surface of the ground in hot climates, would in a short time pollute the air. In this respect, they resemble very much the common flies, which are regarded by the generality of mankind as noxious, and at best, as useless beings in the creation; but this is certainly for want of due consideration. There are not probably in all nature animals of more importance; and it would not be difficult to prove, that we should feel the want of one or two species of large quadrupeds much less than of one or two species of these despicable looking insects. Nothing is more disagreeable or more pestiferous than putrid substances; and it is apparent to all who have made the observation, that these little insects contribute more to the quick dissolution and dispersion of putrescent matter than any other. They are so necessary in all hot climates, that even in the open fields a dead animal or small putrid substance cannot be laid on the ground two minutes, before it will be covered with flies and their maggots, which instantly entering, quickly devour one part, and, perforating the rest in various directions, expose the whole to be much sooner dissipated by the elements. Thus it is with the termites; the rapid vegetation in hot climates, of which no idea can be formed by any thing to be seen in this, is equalled by as great a degree of destruction from natural as well as accidental causes. When trees and even woods are in part destroyed by tornados or fire, it is wonderful to observe how many agents are employed in hastening the total dissolution of the rest; in this business none are so expert or so expeditious and effectual as the termites, who in a few weeks destroy and carry away the bodies of large trees without leaving a particle behind; thus clearing the place for other vegetables, which soon fill up every vacancy. See Encycl. Brit. art. Termes. Edit. The nests of this species are so numerous all over the island of Bananas, and the adjacent continent of Africa, that it is scarcely possible to stand upon any open place, such as a rice plantation, or other clear spot, where one of these buildings is not to be seen almost close to each other. In some parts near Senegal, as mentioned by M. Adanson, their number, magnitude, and closeness of situation, make them appear like the villages of the natives. These buildings are usually termed hills, by the inhabitants as well as strangers, from their outward appearance, which is that of little hills more or less conical, generally very much in the form of sugar-loaves, and about ten or twelve feet in perpendicular height above the common surface of the ground. These hills continue quite bare until they are six or eight feet high; but, in time, the dead barren clay of which they are composed becomes fertilized by the genial power of the elements in these prolific climates, and the addition of vegetable salts and other matters brought by the wind; and in the second or third year the hillock, if not overshaded by trees, becomes like the rest of the earth, almost covered with grass and other plants; and Every one of these buildings consists of two distinct parts, the exterior and interior. The exterior cover is one large clay shell, in the form of a dome, capacious and strong enough to inclose and shelter the interior building from the vicissitudes of the weather, and the inhabitants from the attacks of natural or accidental enemies. The external cover is always, therefore, much stronger than the interior building, which is the habitable part, divided with wonderful regularity and contrivance into an amazing number of apartments for the residence of the king and queen, for the nursing of their numerous progeny, and for magazines, which are always found well filled with stores and provisions. These hills make their first appearance above ground by a little turret or two in the shape of sugar-loaves, which are run a foot high or more; soon after, at some little distance, while the former are increasing in height and size, they rise others, and so go on increasing the number, and widening them at the base, till their works below are covered with these turrets, which the insects always raise highest and largest towards the middle of the hill, and by filling up the intervals between each turret, collect them as it were into one dome. They are not very curious or exact about these turrets, except in making them very solid and strong; and when, by the junction of them, the dome is completed, for which purpose the turrets serve as scaffolds, they take away the middle ones entirely, except the tops, which joined together make the crown of the cupola, and apply the clay to the building of the works within, or to erecting fresh turrets for the purpose of raising the hillock still higher; so that no doubt some The royal chamber, which, on account of its being adapted for, and occupied by the king and queen, appears to be in the opinion of this little people, of the most consequence, is always situated as near the center of the interior building as possible, and generally about the height of the common surface of the ground, at a pace or two from the hillock; it is always nearly in the shape of half an egg or an obtuse oval within, and may be supposed to represent a long oven. In the infant state of the colony, it is not above an inch, or thereabouts, in length; but in time will be increased to six or eight inches or more in the clear, being always in proportion to the size of the queen, who, increasing in bulk as in age, at length requires a chamber of such dimensions. The floor is horizontal, sometimes an inch thick and upward of solid clay; the roof also, which is one solid and well-turned oval arch, is generally of about the same solidity, but in some places it is not a quarter of an inch thick; this is on the sides where it joins the floor, and where the doors or entrances are made. These entrances will not admit any animal larger than the soldiers or labourers; so that the king, and the queen, who is when full grown a thousand times the weight of a king, can never possibly go out. The royal chamber, if in a large hillock, is surrounded by an innumerable quantity of others, of different sizes, shapes, and dimensions; but all of them arched, sometimes of a circular, sometimes of an elliptical form. These chambers either open into each other, or have communicating passages, and being always empty, are evidently made for the soldiers and attendants; of whom, it will soon appear, great numbers are necessary, and of course always in waiting. These apartments are joined by the magazines and nurseries; the former are chambers of clay, and are always well filled with provisions, which to the naked eye seem to consist of the raspings of wood and plants, which the termites destroy, but are found by the microscope to be chiefly composed of the gums or inspissated juices of plants, thrown together in little masses, some of which are finer than others, and resemble the sugar about preserved fruits; others are like drops of gum. The magazines are intermixed with the nurseries, buildings totally different from the rest of the apartments, being composed entirely of wooden materials, seemingly joined together with gums. They are called nurseries because they are invariably occupied by the eggs and young ones, which appear at first in the shape of labourers, but as white as snow. These buildings are exceedingly compact, and divided into many very small irregular-shaped chambers, placed all round the royal apartments, and as near as possible to them. When the nest is in the infant state, the nurseries are close to the royal chamber; but as in process of time the queen increases in size, it is necessary to enlarge the chamber for her accommodation; and as she then lays a greater number of eggs, and requires a more numerous train of attendants, so it is necessary to enlarge and increase the number of the adjacent apartments; for which purpose, the small nurseries which are first built, are taken to pieces, rebuilt a little further off, a size larger, and the number of them increased at the same time. Thus they continually enlarge their apartments, pull down, repair, or rebuild, according to their wants, with a degree of sagacity, regularity, and foresight, not even imitated by any other kind of animals or insects. The nurseries are inclosed in chambers of clay, like those which contain the provisions, but much more extensive. In the early state of the nest they are not larger than an hazel nut, but in great hills are often as large as a child’s head of a year old. The royal chamber is situated nearly on a level with the surface of the ground, at an equal distance from all the sides of the building, and directly under the apex of the hill. It is, on all sides, both above and below, surrounded by what may be called the royal apartments, which have only labourers and soldiers in them, and can be intended for no other purpose than for these to wait in, either to guard or serve their common father and mother, on whose safety depends the happiness, and, according to the account of the negroes, even the existence of the whole community. These apartments form an intricate labyrinth, which extends a foot or more in diameter from the royal chamber on every side. Here the nurseries and magazines of provisions begin, and being separated by small empty chambers and galleries, which go round them, or communicate from one to the other, are continued on all sides to the outward shell, and reach up within it two-thirds or three-fourths of its height, having an open area in the middle under the dome, resembling the nave of an old cathedral. This area is surrounded by large gothic arches, which are sometimes two or three feet high next the front of the area, but diminish very rapidly as they recede from thence, like the arches of aisles in perspective, and are soon lost among the innumerable chambers and nurseries behind them. All these chambers, and the passages leading to and from them, being arched, contribute to support one another; and while the interior large arches prevent their falling into the center, and keep the area open, the exterior building supports them on the outside. The interior building, or assemblage of nurseries, chambers, &c. has a flattish top or roof without any perforation; by this contrivance, if any water should penetrate the external dome, the apartments below are preserved from injury. It is never exactly These subterraneous passages or galleries are lined very thick with the same kind of clay of which the hill is composed, and ascend the inside of the outward shell in a spiral manner; winding round the whole building up to the top, they intersect each other at different heights, opening either immediately into the dome in various places, and into the interior building, the new turrets, &c. or communicating thereto by other galleries of different bores or diameters, either circular or oval. From every part of these large galleries are various small pipes or galleries, leading to different parts of the building; under ground there are a great many which lead downward, by sloping descents three and four feet perpendicular among the gravel, from whence the labouring termites cull the finer parts, which being worked up in their mouths to the consistence of mortar, becomes that solid clay or stone, of which their hills and all their buildings, except the nurseries, are composed. Other galleries again ascend and lead out horizontally on every side, and are carried under ground near to the surface, a vast distance. There is a kind of necessity for the galleries under the hills being thus large, as they are the great thoroughfares for all the labourers and soldiers going forth or returning upon any business whatever, whether fetching clay, wood, water, or provisions; and they are certainly well calculated for the purposes to which they are applied, by the spiral slope which is given them. Those species which build either the roofed turrets, or the nests in the trees, seem in most instances to have a strong resemblance to the preceding, both in their form and oeconomy, going through the same changes from the egg to the winged state. The queens also increase to a great size when compared with the labourers, but very short of those queens before described. The largest are from about an inch to an inch and an half long, and not much thicker than a common quill. There is the same kind of peristaltic motion in the abdomen, but in a much smaller degree; and as the animal is incapable of moving from her place, the eggs, no doubt are carried to the different cells by the labourers, and reared with a care similar to that which is practised in the larger nests. It is remarkable of all these different species, that the working and the fighting insects never expose themselves to the open air, but either travel under ground, or within such trees and substances as they destroy; except, indeed, when they cannot proceed by their latent passages, and find it convenient or necessary to search for plunder above ground: in that case they make pipes of that material with which they build their nests. The larger sort use the red clay; the turret builders use the black clay; and those which build in the trees employ the same ligneous substance of which their nests are composed. The termites, except their heads, are exceedingly soft, and covered with a very thin and delicate skin; being blind, they are no Whenever the termites are dislodged from their covered ways, the various species of formicÆ or ants, who probably are as numerous above ground, as the latter are in their subterraneous passages, instantly seize and drag them away to their nests, to feed the young brood. The termites are, therefore, exceedingly solicitous about the preserving their covered ways in good repair; and if you demolish one of them for a few inches in length, it is wonderful how soon they re-build it. At first in their hurry they get into the open part an inch or two, but stop so suddenly, that it is very apparent they are surprized; for, though some run straight on, and get under the arch as speedily as possible in the further part, most of them run as fast back, and very few will venture through that part of the track which is left uncovered. In a few minutes you will perceive them re-building the arch, and by the next morning they will have restored their gallery for three or four yards in length, if so much has been ruined; and upon opening it again, will be found as numerous as ever under it, passing both ways. If you continue to destroy it several times, they will at length seem to give up the point, and build another in a different direction; but, if the old one should lead to some favourite plunder, in a few days will re-build it again, and, unless you destroy their nest, never totally abandon their, gallery. OF THE HABITATIONS OF CATERPILLARS.Though the view which has already been given of the various proceedings of insects in forming their habitations, has extended to some length, I cannot with propriety omit noticing the wonderful Some species of caterpillars form a kind of hammock, in which they eat and go through their various changes; while others erect a silken tent, under which they live until they have consumed the surrounding herbs. They then leave their abodes, and pitch their tents in a more fruitful spot. Many associate together all their lives; these proceed from the same moth, who deposited her eggs near each other, or rather laid them in a heap, forming as it were a kind of nest. They are generally hatched on the same day, and, living together, constitute a new species of republic, in which all are brethren. They often amount to near six hundred in a family, though they are frequently to be found with only about two hundred. Of these social caterpillars there are some species which not only continue with the society while they are in a larva state, but even place their pupÆ close together. There are other kinds who associate only for a short period. Among the vast variety of insects which inhabit the oak, there is a species of caterpillar which live separate till they arrive at a certain age; they then assemble together, and do not quit each other till they attain their perfect state. As the number thus assembled is considerable, the nest is also very large. They remain in-doors during the day, not leaving their habitation till sun-set. When they go out, one of the body precedes the rest as a chief, whom they regularly follow; when the leader stops, the rest do the same, and wait till it goes on again, before they recommence their march. The first file generally consists of a This mode is followed till they are full grown, when each forms a cone, in which it is changed into a chrysalis. M. Bonnet has shewn, that though these caterpillars proceed often very far from their nest, it is by no means difficult for them to get back again, because they spin over all the places in their rout. The first leads the way, the second follows spinning, the third spins after the first and second, and so on with the rest. All these threads form by degrees a small shining track, a little path; and all these paths meet at the nest. To be fully convinced of the use of these threads, let any one but break the continuation of them in some particular part, and he will see the little caterpillars turn back, as if they were at a loss, till one more daring than the rest restores the communication by spinning new threads. The reader who is desirous of a fuller information concerning the habits of these, as well as many other insects, must be referred to the laborious and interesting memoirs of Reaumur. Happy if he should, like De Geer, be induced thereby to follow the steps of so great a master; he will derive from thence a continual source of new pleasures and increasing delights; and the more he extends the boundaries of his observations, the more he will be convinced that INFINITY is, as it were, impressed on all the works of the Creator. Different species of caterpillars are often to be found in great numbers on the same tree or plant; but then as they seem to have no connection with each other, and the actions of the one have no influence on the rest, they may be considered as solitary; but there are others who seem still more independent of each other, and greater friends to solitude, constructing a lodging formed of leaves tied together with considerable ingenuity, in which they live as in a hermitage. The operation by which these tie the leaves together, is far surpassed by another kind, who fold and bend one part of the leaf till it meets the other. These are again exceeded by those who roll the leaves which they inhabit. For this purpose the caterpillar chooses a part of a leaf which it finds in some degree bent; here it establishes its abode, and begins its work, moving the head with great velocity in a curved line, or rather vibrating it like a pendulum, the middle of the body being the center on which it moves. At each motion of the head a thread is spun, and fixed to that part to which the head seems to be applied. The threads are extended from the bent to the flat part of the leaf, being always adjusted both in length and strength to the nature of the leaf, and the curvature which is to be given to it. De Geer attending to the operations of a species of this kind of caterpillar, observed that at each new thread it spun, the edges of the leaf insensibly approached to each other, and were bent more and more, in proportion as the caterpillar spun new threads; when the last thread that was spun was tight, that which preceded it was loose and floating in the air. To effect this, the caterpillar, after it has fixed a thread to the two edges of the leaf, and before it spins another, draws it towards itself by the hooks of its feet, and by these means bends the leaf; it then spins another thread, to maintain the leaf in this position, which it again pulls A great number of the smaller larvÆ require an artificial covering, to protect them from the open air. Among these, some inhabit the interior parts of leaves, making their way between the superior and inferior membranes, living upon the parenchymous parts of the leaf; and as they are exceedingly small, a leaf affords them a spacious habitation. If the distance between the membranes be not large enough for them, they enlarge the space by forming different folds in one of them, in which they can move with ease: from these circumstances they have been named by Reaumur miners of leaves. This illustrious author has described these larvÆ, the flies into which they are changed, and all the Various methods made use of by them in performing this work. Some mine a large oval or circular space; others form a kind of gallery, which is sometimes straight, sometimes crooked. They only leave a thin membrane on the upper side of the leaf; but they leave the under side more substantial. One species of moth which proceeds from these larvÆ is very small but exceedingly beautiful. The larvÆ of the phryganea mostly live in little cases of their own building, which are formed of a variety of materials, that Having lived in the water for some time, they become inhabitants of the air. They assume the pupa form in the water, closing up the two ends of the case with bars of silk, by which it is secured from the attacks of its enemies; and at the same time there is a free passage for the water, which is still necessary for its existence. At a proper period the pupa forces its way through the case, and makes for the land, where its further change instantly commences, and is soon completed. We shall close these specimens of the industry of insects with an account of that which is displayed by the larvÆ of the tineÆ. The greatest part of the body of these little creatures, except the head and six fore feet, is covered over with a thin tender skin; the body of the insect is cylindrical, and lodged in a tube which is open at both ends. Soon after they are born, they begin to cover themselves, and are, therefore, seldom to be found but in these tubes or cases. They are in general so small, that it is not easy to distinguish the cases without a magnifier; but as the body lengthens, the case becomes too short; it is, therefore, part of its daily employ to lengthen it. For this purpose it extends the head beyond the tube, and having found the materials which answer its purpose, it tears it off, and brings it to the end of the tube, and fixes it there, repeating this manoeuvre till it has sufficiently lengthened it. After it has finished one end, it This does not terminate their labours, for the tube must also be increased in diameter, as it soon becomes too small for the body; the means they make use of to enlarge it, is precisely the same as we ourselves should adopt under similar circumstances. The insect slits the tube at the two opposite sides, at the same end, and inserts in the slit two pieces of the required size; it then performs the same at the other end. By these means they soon enlarge it sufficiently, without exposing themselves to the air during the operation. The outside of these cases is made of silk, hair, &c. the inside is of silk only. Their covering always partakes of the colour of the cloth or tree, &c. from whence it was taken; if it pass over a red piece, the colour will be red. When they are come to their perfect growth, they abandon the cloth, and seek for a proper place wherein they may pass from their present to a more perfect state. I cannot conclude this long chapter better than in the words of Mr. Stillingfleet. “Many are apt to treat with contempt any man whom they see employed in poring over a moss, or examining an insect, from day to day, thinking that he spends his time and his life in unimportant and barren speculations; yet were the whole scene of nature laid open to our views, were we admitted to behold the connections and dependences of every thing on every other, and to trace the oeconomy of nature through the smaller, as well as greater parts of this globe, we might, perhaps, be obliged to own that we were mistaken; that the Supreme Architect had contrived his works in such a manner, that we cannot properly be said to be unconcerned in any one of them; and, therefore, that studies, which seem upon a slight view to be quite useless, may in the end appear of no small importance “It is true, this does not always happen to the searcher, or his contemporaries, nor even sometimes to the immediate succeeding generation; but I am apt to think, that advantages of one kind or other always accrue to mankind from such pursuits; some men are born to observe and record what perhaps by itself is perfectly useless, but yet of great importance to another who follows and goes a step further, still as useless; to him another succeeds, and thus by degrees, till at last one of a superior genius comes, who laying all that has been done before this time together, brings on a new face of things, improves, adorns, exalts human society. “All those speculations concerning lines and numbers, so ardently pursued, and so exquisitely conducted by the Grecians, what did they aim at? or what did they produce for ages? a little arithmetic, and the first elements of geometry, were all they had need of. This Plato asserts; and though, as being himself an able mathematician, and remarkably fond of these sciences, he recommends the study of them; yet he makes use of motives that have no relation to the common purposes of life. “When Kepler, from a blind and strong impulse, merely to find analogies in nature, discovered that famous one between the distance of the several planets from the sun, and the periods in which they complete their revolutions, of what importance was it to him or the world? “Again; when Galileo, pushed on by the same irresistible curiosity, found out the law by which bodies fall to the earth, did he, or could he foresee that any good would come from his ingenious theorems; or was any immediate use made of them? “Yet had not the Greeks pushed their abstract speculations so far, had not Kepler and Galileo made the above-mentioned discoveries, we never could have seen the greatest work that ever came from the hands of man, Sir Isaac Newton’s Principia. “Some obscure person, whose name is not so much as known, diverting himself idly, as a stander-by would have thought, with trying experiments on a seemingly contemptible piece of stone, found out a guide for mariners on the ocean, and such a guide as no science, however subtil and sublime its speculations may be, however wonderful its conclusions, would ever have arrived at. It was mere curiosity that put Sir Thomas Millington upon examining the minute parts of flowers; but his discoveries have produced the most perfect and most useful system of botany that the world has yet seen. “Other instances might be produced to prove, that bare curiosity in one age, is the source of the greatest utility in another; and what has frequently been said of chemists, may be applied to every other kind of vertuosi. They hunt, perhaps, after chimeras and impossibilities; they find something really valuable by the bye. We are but instruments under the Supreme Director, and do not so much as know, in many cases, what is of most importance for us to search after; but we may be sure of one thing, viz. that if we study and follow nature, whatever paths we are led into, we shall at last arrive at something valuable to ourselves and others, but of what kind we must be content to remain ignorant.” |
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