[Plate I]

AN

INTRODUCTION

TO

ENTOMOLOGY:

OR

ELEMENTS

OF THE

NATURAL HISTORY OF INSECTS:

WITH PLATES.

By WILLIAM KIRBY, M.A. F.R. AND L.S.

RECTOR OF BARHAM,
AND

WILLIAM SPENCE, Esq. F.L.S.

IN FOUR VOLUMES.

VOL. I.

FIFTH EDITION.

LONDON:

PRINTED FOR

LONGMAN, REES, ORME, BROWN, AND GREEN,

PATERNOSTER ROW.

1828.

LONDON:

PRINTED BY RICHARD TAYLOR,

RED LION COURT, FLEET STREET.

TO
THE RIGHT HONOURABLE

Sir JOSEPH BANKS, Baronet,

ONE OF HIS MAJESTY'S MOST HONOURABLE PRIVY
COUNCIL,
KNIGHT GRAND CROSS OF THE ORDER OF THE BATH,
PRESIDENT OF THE ROYAL SOCIETY, ETC.
WHOSE UNRIVALLED LIBRARY AND
PERSONAL COMMUNICATIONS
HAVE FURNISHED MUCH OF THE MOST INTERESTING
MATTER THAT IT CONTAINS,

THE FOLLOWING WORK,

IN WHICH AN ATTEMPT IS MADE TO COPY
HIS ILLUSTRIOUS EXAMPLE,
BY POINTING OUT THE CONNEXION THAT EXISTS
BETWEEN NATURAL SCIENCE, AND AGRICULTURE,
AND THE ARTS,
IS, WITH HIS PERMISSION,
MOST GRATEFULLY INSCRIBED
BY HIS MOST OBLIGED

AND OBEDIENT SERVANTS,
THE AUTHORS.

ADVERTISEMENT

TO THIS EDITION.

Since the original Edition of the present work was published, a gradual and great alteration has taken place in the nomenclature of the genera, occasioned by the old ones being further subdivided according to their natural groups, and each distinguished as a genus or subgenus by its peculiar name. These names in the present Edition, in order to keep pace with the progress of the science, have been generally adopted, and some new ones introduced. The improved Index, which may be had separately by the purchasers of the former Editions, will point out from what old genera the new ones have been separated.

[PREFACE.]

One principal cause of the little attention paid to Entomology in this country, has doubtless been the ridicule so often thrown upon the science. The botanist, sheltered now by the sanction of fashion, as formerly by the prescriptive union of his study with medicine, may dedicate his hours to mosses and lichens without reproach; but in the minds of most men, the learned as well as the vulgar, the idea of the trifling nature of his pursuit is so strongly associated with that of the diminutive size of its objects, that an entomologist is synonymous with every thing futile and childish. Now, when so many other roads to fame and distinction are open, when a man has merely to avow himself a botanist, a mineralogist, or a chemist—a student of classical literature or of political economy—to ensure attention and respect, there are evidently no great attractions to lead him to a science which in nine companies out of ten with which he may associate promises to signalize him only as an object of pity or contempt. Even if he have no other aim than self-gratification, yet "the sternest stoic of us all wishes at least for some one to enter into his views and feelings, and confirm him in the opinion which he entertains of himself:" but how can he look for sympathy in a pursuit unknown to the world, except as indicative of littleness of mind[1]?

Yet such are the genuine charms of this branch of the study of nature, that here as well as on the continent, where, from being equally slighted, Entomology now divides the empire with her sister Botany, this obstacle would not have been sufficient to deter numbers from the study, had not another more powerful impediment existed—the want of a popular and comprehensive Introduction to the science. While elementary books on Botany have been multiplied amongst us without end and in every shape, Curtis's translation of the Fundamenta Entomologiæ, published in 1772; Yeats's Institutions of Entomology, which appeared the year after; and Barbut's Genera Insectorum, which came out in 1781—the two former in too unattractive, and the latter in too expensive a form for general readers—are the only works professedly devoted to this object, which the English language can boast.

Convinced that this was the chief obstacle to the spread of Entomology in Britain, the authors of the present work resolved to do what was in their power to remove it, and to introduce their countrymen to a mine of pleasure, new, boundless, and inexhaustible, and which, to judge from their own experience—formed in no contracted field of comparison—they can recommend as possessing advantages and attractions equal to those held forth by most other branches of human learning.

The next question was, in what way they should attempt to accomplish this intention. If they had contented themselves with the first suggestion that presented itself, and merely given a translation of one of the many Introductions to Entomology extant in Latin, German and French, adding only a few obvious improvements, their task would have been very easy; but the slightest examination showed that, in thus proceeding, they would have stopped far short of the goal which they were desirous of reaching.—In the technical department of the science they found much confusion, and numerous errors and imperfections—the same name sometimes applied to parts anatomically quite different, and different names to parts essentially the same, while others of primary importance were without any name at all. And with reference to the anatomy and physiology of insects, they could no where meet with a full and accurate generalization of the various facts connected with these subjects, scattered here and there in the pages of the authors who have studied them.

They therefore resolved to begin, in some measure, de novo—to institute a rigorous revision of the terms employed, making such additions and improvements as might seem to be called for; and to attempt a more complete and connected account of the existing discoveries respecting the anatomical and physiological departments of the science than has yet been given to the world:—and to these two points their plan at the outset was limited.

It soon, however, occurred to them, that it would be of little use to write a book which no one would peruse; and that in the present age of love for light reading, there could not be much hope of leading students to the dry abstractions of the science, unless they were conducted through the attractive portal of the economy and natural history of its objects. To this department, therefore, they resolved to devote the first and most considerable portion of their intended work, bringing into one point of view, under distinct heads, the most interesting discoveries of Reaumur, De Geer, Bonnet, Lyonet, the Hubers, &c., as well as their own individual observations, relative to the noxious and beneficial properties of insects; their affection for their young; their food, and modes of obtaining it; their habitations; societies; &c. &c.: and they were the more induced to adopt this plan, from the consideration, that, though many of the most striking of these facts have before been presented to the English reader, a great proportion are unknown to him; and that no similar generalization (if a slight attempt towards it in Smellie's Philosophy of Natural History, and a confessedly imperfect one in Latreille's Histoire Naturelle des Crustacés et des Insectes be excepted) has ever been attempted in any language.—Thus the entire work would be strictly on the plan of the Philosophia Entomologica of Fabricius, only giving a much greater extent to the Œconomia and Usus, and adverting to these in the first place instead of in the last.

The epistolary form was adopted, not certainly from any idea of their style being particularly suited to a mode of writing so difficult to keep from running into incongruities: but simply because this form admitted of digressions and allusions called for in a popular work, but which might have seemed misplaced in a stricter kind of composition;—because it is better suited to convey those practical directions, which in some branches of the pursuit the student requires;—and lastly, because by this form, the objection against speaking of the manners and economy of insects before entering upon the definition of them, and explaining the terms of the science—a retrograde course, which they have chosen from their desire to present the most alluring side of the science first—is in great measure, if not wholly, obviated.

Such is the plan which the authors chalked out for themselves—a plan which in the execution they have found so much more extensive than they calculated upon, that, could they have foreseen the piles of volumes through which it has entailed upon them the labour of wading, often to glean scarcely more than a single fact—the numerous anatomical and technological investigations which it has called for—and the long correspondence, almost as bulky as the entire work, unavoidably rendered necessary by the distant residence of the parties—they would have shrunk from an undertaking, of which the profit, if by great chance there should be any, could not be expected to repay even the cost of books required in it, and from which any fame must necessarily be confined to a very limited circle. But having entered upon it, they have persevered; and if they succeed in their grand aim, that of making converts amongst their countrymen to a study equally calculated for promoting the glory of God and the delight and profit of man, they will not deem the labour of the leisure hours of six years ill bestowed.

And here it may be proper to observe, that one of their first and favourite objects has been to direct the attention of their readers "from nature up to nature's God." For, when they reflected upon the fatal use which has too often been made of Natural History, and that from the very works and wonders of God, some philosophists, by an unaccountable perversion of intellect, have attempted to derive arguments either against his being and providence, or against the Religion revealed in the Holy Scriptures, they conceived they might render some service to the most important interests of mankind, by showing how every department of the science they recommend illustrates the great truths of Religion, and proves that the doctrines of the Word of God, instead of being contradicted, are triumphantly confirmed by his Works.

"To see all things in God" has been accounted one of the peculiar privileges of a future state; and in this present life, "to see God in all things," in the mirror of the creation to behold and adore the reflected glory of the Creator, is no mean attainment; and it possesses this advantage, that thus we sanctify our pursuits, and, instead of loving the creatures for themselves, are led by the survey of them and their instincts to the love of Him who made and endowed them.

Of their performance of the first part of their plan, in which there is the least room for originality, it is only necessary for the authors to say that they have done their best to make it as comprehensive, as interesting, and as useful as possible: but it is requisite to enter somewhat more fully into what has been attempted in the anatomical, physiological, and technical parts of the work.

As far as respects the general physiology and internal anatomy of insects, they have done little more than bring together and combine the observations of the naturalists who have attended to these branches of the science: but the external anatomy they have examined for themselves through the whole class, and, they trust, not without some new light being thrown upon the subject; particularly by pointing out and giving names to many parts never before noticed.

In the Terminology, or what, to avoid the barbarism of a word compounded of Latin and Greek, they would beg to call the Orismology of the science, they have endeavoured to introduce throughout a greater degree of precision and concinnity—dividing it into general and partial Orismology;—under the former head defining such terms as relate to Substance, Resistance, Density, Proportion, Figure, Form, Superficies, (under which are introduced Sculpture, Clothing, Colour, &c.) Margin, Termination, Incision, Ramification, Division, Direction, Situation, Connection, Arms, &c.; and under the latter those that relate to the body and its parts and members, considered in its great subdivisions of Head, Trunk, and Abdomen. In short, they may rest their claim of at least aiming at considerable improvement in this department upon the great number of new terms, and alterations of old ones, which they have introduced—in external Anatomy alone falling little short of 150. If it should be thought by any one that they have made too many changes, they would remind him of the advice of Bergman to Morveau, when reforming the nomenclature of Chemistry, the soundness of which Dugald Stewart has recognised—"Ne faites grace à aucune dénomination impropre. Ceux qui savent déjà, entendront toujours; ceux qui ne savent pas encore, entendront plutôt."

Throughout the whole publication, wherever any fact of importance not depending on their own authority is mentioned, a reference to the source whence it has been derived is generally given; so that, if the work should have no other value, it will possess that of saving much trouble to future inquirers, by serving as an index to direct them in their researches.

The authors are perfectly sensible that, notwithstanding all their care and pains, many imperfections will unavoidably remain in their work. There is no science to which the adage, Dies diem docet, is more strikingly applicable than to Natural History. New discoveries are daily made, and will be made it is probable to the end of time; so that whoever flatters himself that he can produce a perfect work in this department will be miserably disappointed. The utmost that can reasonably be expected from naturalists is to keep pace with the progress of knowledge, and this the authors have used their best diligence to accomplish. Every new year since they took the subject in hand up to the very time when the first sheets were sent to the press, numerous corrections and alterations have suggested themselves; and thus they are persuaded it would be were they to double the period of delay prescribed by Horace. But Poetry and Natural History are on a different footing; and though an author can plead little excuse for giving his verses to the world while he sees it possible to polish them to higher excellence, the naturalist, if he wishes to promote the extension of his science, must be content to submit his performances to the public disfigured by numerous imperfections.

In the introductory letter several of the advantages to be derived from the study of Entomology are pointed out; but there is one, which, though it could not well have been insisted upon in that place, is too important to be passed over without notice—its value in the education of youth.

All modern writers on this momentous subject unite in recommending in this view, Natural History: and if "the quality of accurate discrimination—the ready perception of resemblances amongst diversities, and still more the quick and accurate perception of diversity in the midst of resemblances—constitutes one of the most important operations of the understanding; if it be indeed the foundation of clear ideas, and the acquisition of whatever can be truly called knowledge depends most materially on the possession of it:"—if "the best logic be that which teaches us to suspend our judgements;" and "the art of seeing, so useful, so universal, and yet so uncommon, be one of the most valuable a man can possess,"—there can be no doubt of the judiciousness of their advice. Now of all the branches of Natural History, Entomology is unquestionably the best fitted for thus disciplining the mind of youth; and simply from these circumstances, that its objects have life, are gifted with surprising instincts admirably calculated to attract youthful attention, and are to be met with every where. It is not meant to undervalue the good effects of the study of Botany or Mineralogy: but it is self-evident that nothing inanimate can excite such interest in the mind of a young person as beings endowed with vitality, exercising their powers and faculties in so singular a way; which, as Reaumur observes, are not only alive themselves, but confer animation upon the leaves, fruits, and flowers that they inhabit; which every walk offers to view; and on which new observations may be made without end.

Besides these advantages, no study affords a fairer opportunity of leading the young mind by a natural and pleasing path to the great truths of Religion, and of impressing it with the most lively ideas of the power, wisdom, and goodness of the Creator.

Not that it is recommended to make children collectors of insects, nor that young people, to the neglect of more important duties and pursuits, should generally become professed Entomologists; but, if the former be familiarized with their names, manners, and economy, and the latter initiated into their classification, it will be an excellent method of strengthening their habits of observation, attention, and memory, equal perhaps, in this respect, to any other mental exercise: and then, like Major Gyllenhal, who studied Entomology under Thunberg about 1770, and after an interval of twenty years devoted to the service of his country, resumed his favourite pursuit with all the ardour of youth, and is at this time giving to the world a description of the insects of Sweden invaluable for its accuracy and completeness—they would be provided in their old age with an object capable not merely of keeping off that tædium vitæ so often inseparable from the relinquishment of active life, but of supplying an unfailing fund of innocent amusement, an incentive to exercise, and consequently no mean degree of health and enjoyment.

Some, who, with an ingenious author[2], regard as superfluous all pains to show the utility of Natural History in reference to the common purposes of life, asking "if it be not enough to open a source of copious and cheap amusement, which tends to harmonize the mind, and elevate it to worthy conceptions of nature and its Author? if a greater blessing to a man can be offered than happiness at an easy rate unalloyed by any debasing mixture?"—may think the earnestness displayed on this head, and the length which has been gone in refuting objections, needless. But Entomology is so peculiarly circumstanced, that without removing these obstacles, there could be no hope of winning votaries to the pursuit. Pliny felt the necessity of following this course in the outset of his book which treats on insects, and a similar one has been originally called for in introducing the study even to those countries where the science is now most honoured. In France, Reaumur, in each of the successive volumes of his immortal work, found it essential to seize every opportunity of showing that the study of insects is not a frivolous amusement, nor devoid of utility, as his countrymen conceived it; and in Germany Sulzer had to traverse the same road, telling us, in proof of the necessity of this procedure, that on showing his works on insects with their plates to two very sensible men, one commended him for employing his leisure hours in preparing prints that would amuse children and keep them out of mischief, and the other admitted that they might furnish very pretty patterns for ladies' aprons! And though in this country things are not now quite so bad as they were when Lady Glanville's will was attempted to be set aside on the ground of lunacy, evinced by no other act than her fondness for collecting insects, and Ray had to appear at Exeter on the trial as a witness of her sanity[3], yet nothing less than line upon line can be expected to eradicate the deep-rooted prejudices which prevail on this subject. "Old impressions," as Reaumur has well observed, "are with difficulty effaced. They are weakened, they appear unjust even to those who feel them, at the moment they are attacked by arguments which are unanswerable; but the next instant the proofs are forgotten, and the perverse association resumes its empire."

The authors do not know that any curiosity will be excited to ascertain what share has been contributed to the work by each of them; but if there should, it is a curiosity they must be excused from gratifying. United in the bonds of a friendship, which, though they have to thank Entomology for giving birth to it, is founded upon a more solid basis than mere community of scientific pursuits, they wish that, whether blame or praise is the fate of their labours, it may be jointly awarded. All that they think necessary to state is, that the composition of each of the different departments of the work has been, as nearly as possible, divided between them;—that though the letter, or series of letters, on any particular subject, has been usually undertaken by one, some of the facts and illustrations have generally been supplied by the other, and there are a few to which they have jointly contributed;—and that, throughout, the facts for which no other authority is quoted, are to be considered as resting upon that of one or other of the authors, but not always of him, who, from local allusions, may be conceived the writer of the letter in which they are introduced, as the matter furnished by each to the letters of the other must necessarily be given in the person of the supposed writer.

In acknowledging their obligations to their friends, the first place is due to Simon Wilkin, Esq. of Costessey near Norwich, to whose liberality they are indebted for almost all the plates which illustrate and adorn the work; most of which have been drawn and engraved by his artist Mr. John Curtis, whose intimate acquaintance with the subject has enabled him to give to the figures an accuracy which they could not have received from one less conversant with the science. Nor is the reader less under obligation to Mr. Wilkin's liberality than the authors, who, if the drawings, &c. had been to be paid for, must necessarily have contented themselves with giving a much smaller number.

To Alexander MacLeay, Esq. they are under particular obligations, for the warm interest he has all along taken in the work, the judicious advice he has on many occasions given, the free access in which he has indulged the authors to his unrivalled cabinet and well-stored library, and the numerous other attentions and accommodations by which he has materially assisted them in its progress.

To the other friends who have kindly aided them in this undertaking in any way, they beg here to offer their best thanks.

[CONTENTS OF VOL. I.]

AN INTRODUCTION TO ENTOMOLOGY.

[LETTER I.]

Dear Sir,

I cannot wonder that an active mind like yours should experience no small degree of tedium in a situation so far removed, as you represent your new residence to be, from "the busy hum of men." Nothing certainly can compensate for the want of agreeable society; but since your case in this respect admits of no remedy but patience, I am glad you are desirous of turning your attention to some pursuit which may amuse you in the intervals of severer study, and in part supply the void of which you complain. I am not a little flattered that you wish to be informed which class in the three kingdoms of nature is, in my opinion, most likely to answer your purpose; at the same time intimating that you feel inclined to give the preference to Entomology, provided some objections can be satisfactorily obviated, which you have been accustomed to regard as urged with a considerable semblance of reason against the cultivation of that science.

Mankind in general, not excepting even philosophers, are prone to magnify, often beyond its just merit, the science or pursuit to which they have addicted themselves, and to depreciate any that seems to stand in competition with their favourite: like the redoubted champions of romance, each thinks himself bound to take the field against every one that will not subscribe to the peerless beauty and accomplishments of his own Dulcinea. In such conflict for pre-eminence I know no science that, in this country, has come off worse than Entomology: her champions hitherto have been so few, and their efforts so unavailing, that all her rival sisters have been exalted above her: and I believe there is scarcely any branch of Natural History that has had fewer British admirers. While Botany boasts of myriads, she, though not her inferior either in beauty, symmetry, or grace, has received the homage of a very slender train indeed. Since therefore the merits of Entomology have been so little acknowledged, you will not deem it invidious if I advocate the cause of this distressed damsel, and endeavour to effect her restoration to her just rights, privileges, and rank.

Things that are universally obvious and easy of examination, as they are the first that fall under our notice, so are they also most commonly those which we first feel an inclination to study; while, on the contrary, things that must be sought for in order to be seen, and which when sought for avoid the approach and inquiring eye of man, are often the last to which he directs his attention. The vegetable kingdom stands in the former predicament. Flora with a liberal hand has scattered around us her charming productions; they every where meet and allure us, enchanting us by their beauty, regaling us by their fragrance, and interesting us as much by their subservience to our luxuries and comfort, as to the necessary support and well-being of our life. Beasts, birds, and fishes also, in some one or other of these respects, attract our notice; but insects, unfortunate insects, are so far from attracting us, that we are accustomed to abhor them from our childhood. The first knowledge that we get of them is as tormentors; they are usually pointed out to us by those about us as ugly, filthy, and noxious creatures; and the whole insect world, butterflies perhaps and some few others excepted, are devoted by one universal ban to proscription and execration, as fit only to be trodden under our feet and crushed: so that often, before we can persuade ourselves to study them, we have to remove from our minds prejudices deeply rooted and of long standing.

Another principal reason which has contributed to keep Entomology in the back ground arises from the diminutive size of the objects of which it treats. Being amongst the most minute of nature's productions, they do not so readily catch the eye of the observer; and when they do, mankind in general are so apt to estimate the worth and importance of things by their bulk, that because we usually measure them by the duodecimals of an inch instead of by the foot or by the yard, insects are deemed too insignificant parts of the creation, and of too little consequence to its general welfare, to render them worthy of any serious attention or study. What small foundation there is for such prejudices and misconception, I shall endeavour to show in the course of our future correspondence; my object now, as the champion and advocate of Entomology, is to point out to you her comparative advantages, and to remove the veil which has hitherto concealed those attractions, and that grace and beauty, which entitle her to equal admiration at least with her sister branches of Natural History.

In estimating the comparative value of the study of any department in this branch of science, we ought to contrast it with others, as to the rank its objects hold in the scale of being; the amusement and instruction which the student may derive from it; and its utility to society at large. With respect to public utility, the study of each of the three kingdoms may perhaps be allowed to stand upon nearly an equal footing; I shall not, therefore, enter upon that subject till I come to consider the question Cui bono? and to point out the uses of Entomology, but confine myself now to the two first of these circumstances.

As to rank, I must claim for the entomologist some degree of precedence before the mineralogist and the botanist. The mineral kingdom, whose objects are neither organized nor sentient, stands certainly at the foot of the scale. Next above this is the vegetable, whose lovely tribes, though not endued with sensation, are organized. In the last and highest place ranks the animal world, consisting of beings that are both organized and sentient. To this scale of precedence the great modern luminary of Natural History, notwithstanding that Botany was always his favourite pursuit, has given his sanction, acknowledging in the preface to his Fauna Suecica, that although the vegetable kingdom is nobler than the mineral, yet the animal is more excellent than the vegetable. Now it is an indisputable axiom, I should think, that the more exalted the object the more excellent the study. By this observation, however, I would by no means be thought to depreciate or discountenance the study either of plants or minerals. All the works of our Creator are great, and worthy of our attention and investigation, the lowest in the scale as well as the highest, the most minute and feeble, as well as those that exceed in magnitude and might. Nor ought those whose inclination or genius leads them to one department, to say to those who prefer another—"we have no need of you"—for each in his place, by diffusing the knowledge of his works and adding to the stock of previous discoveries, contributes to promote the glory of the Great Architect of the universe and the good of his creatures.

It is not my wish to claim for my favourite science more than of right belongs to her; therefore, when the question is concerning rank, I must concede to the higher orders of animals, I mean Fishes, Amphibia, Birds, and Quadrupeds, their due priority and precedence. I shall only observe here, that there may exist circumstances which countervail rank, and tend to render the study of a lower order of beings more desirable than that of a higher: when, for instance, the objects of the higher study are not to be come at or preserved without great difficulty and expense; when they are few in number; or, when they are already well ascertained and known: circumstances which attach to the study of those animals that precede insects, while they do not attach to the study of insects themselves.

With regard to the amusement and instruction of the student, much doubtless may be derived from any one of the sciences alluded to: but Entomology certainly is not behind any of her sisters in these respects; and if you are fond of novelty, and anxious to make new discoveries, she will open to you a more ample field for these than either Botany or the higher branches of Zoology.

A new vertebrate animal or plant is seldom to be met with even by those who have leisure and opportunity for extensive researches; but if you collect insects, you will find, however limited the manor upon which you can pursue your game, that your efforts are often rewarded by the capture of some non-descript or rarity at present not possessed by other entomologists, for I have seldom seen a cabinet so meagre as not to possess some unique specimen. Nay, though you may have searched every spot in your neighbourhood this year, turned over every stone, shaken every bush or tree, and fished every pool, you will not have exhausted its insect productions. Do the same another and another, and new treasures will still continue to enrich your cabinet. If you leave your own vicinity for an entomological excursion, your prospects of success are still further increased; and even if confined in bad weather to your inn, the windows of your apartment, as I have often experienced, will add to your stock. If a sudden shower obliges you at any time to seek shelter under a tree, your attention will be attracted, and the tedium of your station relieved, where the botanist could not hope to find even a new lichen or moss, by the appearance of several insects, driven there perhaps by the same cause as yourself, that you have not observed before. Should you, as I trust you will, feel a desire to attend to the manners and economy of insects, and become ambitious of making discoveries in this part of entomological science, I can assure you, from long experience, that you will here find an inexhaustible fund of novelty. For more than twenty years my attention has been directed to them, and during most of my summer walks my eyes have been employed in observing their ways; yet I can say with truth, that so far from having exhausted the subject, within the last six months I have witnessed more interesting facts respecting their history than in many preceding years. To follow only the insects that frequent your own garden, from their first to their last state, and to trace all their proceedings, would supply an interesting amusement for the remainder of your life, and at its close you would leave much to be done by your successor; for where we know thoroughly the history of one insect, there are hundreds concerning which we have ascertained little besides the bare fact of their existence.

But numerous other sources of pleasure and information will open themselves to you, not inferior to what any other science can furnish, when you enter more deeply into the study. Insects, indeed, appear to have been nature's favourite productions, in which, to manifest her power and skill, she has combined and concentrated almost all that is either beautiful and graceful, interesting and alluring, or curious and singular, in every other class and order of her children. To these, her valued miniatures, she has given the most delicate touch and highest finish of her pencil. Numbers she has armed with glittering mail, which reflects a lustre like that of burnished metals[4]; in others she lights up the dazzling radiance of polished gems[5]. Some she has decked with what looks like liquid drops, or plates of gold and silver[6]; or with scales or pile, which mimic the colour and emit the ray of the same precious metals[7]. Some exhibit a rude exterior, like stones in their native state[8], while others represent their smooth and shining face after they have been submitted to the tool of the polisher: others, again, like so many pygmy Atlases bearing on their backs a microcosm, by the rugged and various elevations and depressions of their tuberculated crust, present to the eye of the beholder no unapt imitation of the unequal surface of the earth, now horrid with mis-shapen rocks, ridges, and precipices—now swelling into hills and mountains, and now sinking into valleys, glens, and caves[9]; while not a few are covered with branching spines, which fancy may form into a forest of trees[10].

What numbers vie with the charming offspring of Flora in various beauties! some in the delicacy and variety of their colours, colours not like those of flowers evanescent and fugitive, but fixed and durable, surviving their subject, and adorning it as much after death as they did when it was alive; others, again, in the veining and texture of their wings; and others in the rich cottony down that clothes them. To such perfection, indeed, has nature in them carried her mimetic art, that you would declare, upon beholding some insects, that they had robbed the trees of their leaves to form for themselves artificial wings, so exactly do they resemble them in their form, substance, and vascular structure; some representing green leaves, and others those that are dry and withered[11]. Nay, sometimes this mimicry is so exquisite, that you would mistake the whole insect for a portion of the branching spray of a tree[12]. No mean beauty in some plants arises from the fluting and punctuation of their stems and leaves, and a similar ornament conspicuously distinguishes numerous insects, which also imitate with multiform variety, as may particularly be seen in the caterpillars of many species of the butterfly tribe (Papilionidæ), the spines and prickles which are given as a Noli me tangere armour to several vegetable productions.

In fishes the lucid scales of varied hue that cover and defend them are universally admired, and esteemed their peculiar ornament; but place a butterfly's wing under a microscope, that avenue to unseen glories in new worlds, and you will discover that nature has endowed the most numerous of the insect tribes with the same privilege, multiplying in them the forms[13], and diversifying the colouring of this kind of clothing beyond all parallel. The rich and velvet tints of the plumage of birds are not superior to what the curious observer may discover in a variety of Lepidoptera; and those many-coloured eyes which deck so gloriously the peacock's tail are imitated with success by one of our most common butterflies[14]. Feathers are thought to be peculiar to birds; but insects often imitate them in their antennæ[15], wings[16], and even sometimes in the covering of their bodies[17].—We admire with reason the coats of quadrupeds, whether their skins be covered with pile, or wool, or fur; yet are not perhaps aware that a vast variety of insects are clothed with all these kinds of hair, but infinitely finer and more silky in texture, more brilliant and delicate in colour, and more variously shaded than what any other animals can pretend to.

In variegation insects certainly exceed every other class of animated beings. Nature, in her sportive mood, when painting them, sometimes imitates the clouds of heaven; at others, the meandering course of the rivers of the earth, or the undulations of their waters: many are veined like beautiful marbles; others have the semblance of a robe of the finest net-work thrown over them; some she blazons with heraldic insignia, giving them to bear in fields sable—azure—vert—gules—argent and or, fesses—bars—bends—crosses—crescents—stars, and even animals[18]. On many, taking her rule and compasses, she draws with precision mathematical figures; points, lines, angles, triangles[19], squares, and circles. On others she portrays, with mystic hand, what seem like hieroglyphic symbols, or inscribes them with the characters and letters of various languages, often very correctly formed[20]; and, what is more extraordinary, she has registered in others figures which correspond with several dates of the Christian era[21].

Nor has nature been lavish only in the apparel and ornament of these privileged tribes; in other respects she has been equally unsparing of her favours. To some she has given fins like those of fish, or a beak resembling that of birds[22]; to others horns, nearly the counterparts of those of various quadrupeds. The bull[23], the stag[24], the rhinoceros[25], and even the hitherto vainly sought for unicorn[26], have in this respect many representatives amongst insects. One is armed with tusks not unlike those of the elephant[27]; another is bristled with spines, as the porcupine and hedge-hog with quills[28]; a third is an armadillo in miniature; the disproportioned hind legs of the kangaroo give a most grotesque appearance to a fourth[29]; and the threatening head of the snake is found in a fifth[30]. It would, however, be endless to produce all the instances which occur of such imitations: and I shall only remark that, generally speaking, these arms and instruments in structure and finishing far exceed those which they resemble.

But further, insects not only mimic, in a manner infinitely various, every thing in nature, they may also with very little violence be regarded as symbolical of beings out of and above nature. The butterfly, adorned with every beauty and every grace, borne by radiant wings through the fields of ether, and extracting nectar from every flower, gives us some idea of the blessed inhabitants of happier worlds, of angels, and of the spirits of the just arrived at their state of perfection. Again, other insects seem emblematical of a different class of unearthly beings: when we behold some tremendous for the numerous horns and spines projecting in horrid array from their head or shoulders;—others for their threatening jaws of fearful length, and armed with cruel fangs: when we survey the dismal hue and demoniac air that distinguish others, the dens of darkness in which they live, the impurity of their food, their predatory habits and cruelty, the nets which they spread, and the pits which they sink to entrap the unwary, we can scarcely help regarding them as aptly symbolizing evil demons, the enemies of man, or of impure spirits for their vices and crimes driven from the regions of light into darkness and punishment[31].

The sight indeed of a well-stored cabinet of insects will bring before every beholder not conversant with them, forms in endless variety, which before he would not have thought it possible could exist in nature, resembling nothing that the other departments of the animal kingdom exhibit, and exceeding even the wildest fictions of the most fertile imagination. Besides prototypes of beauty and symmetry, there in miniature he will be amused to survey (for the most horrible creatures when deprived of the power of injury become sources of interest and objects of curiosity), to use the words of our great poet,

... all prodigious things
Abominable, unutterable, and worse
Than fables yet have feign'd, or fear conceiv'd,
Gorgons, and Hydras, and Chimæras dire.

But the pleasures of a student of the science to which I am desirous of introducing you, are far from being confined to such as result from an examination of the exterior form and decorations of insects: for could these, endless as they seem, be exhausted, or, wonderful as they are, lose their interest, yet new sources, exuberant in amusement and instruction, may be opened, which will furnish an almost infinite fund for his curiosity to draw upon. The striking peculiarity and variety of structure which they exhibit in their instruments of nutrition, motion, and oviposition; in their organs of sensation, generation, and the great fountains of vitality,—indeed their whole system, anatomically considered, will open a world of wonders to you with which you will not soon be satiated, and during your survey of which you will at every step feel disposed to exclaim with the Roman naturalist—"In these beings so minute, and as it were such non-entities, what wisdom is displayed, what power, what unfathomable perfection[32]!" But even this will not bring you to the end of your pleasures: you must leave the dead to visit the living; you must behold insects when full of life and activity, engaged in their several employments, practising their various arts, pursuing their amours, and preparing habitations for their progeny: you must notice the laying and kind of their eggs; their wonderful metamorphoses; their instincts, whether they be solitary or gregarious; and the other miracles of their history—all of which will open to you a richer mine of amusement and instruction, I speak it without hesitation, than any other department of Natural History can furnish. A minute enumeration of these particulars would be here misplaced, and only forestall what will be detailed more at large hereafter; but a rapid glance at a very few of the most remarkable of them, may serve as a stimulus to excite your curiosity, and induce you to enter with greater eagerness into the wide field to which I shall conduct you.

The lord of the creation plumes himself upon his powers of invention, and is proud to enumerate the various useful arts and machines to which they have given birth, not aware that "He who teacheth man knowledge" has instructed these despised insects to anticipate him in many of them. The builders of Babel doubtless thought their invention of turning earth into artificial stone, a very happy discovery[33]; yet a little bee[34] had practised this art, using indeed a different process, on a small scale, and the white ants on a large one, ever since the world began. Man thinks that he stands unrivalled as an architect, and that his buildings are without a parallel among the works of the inferior orders of animals. He would be of a different opinion did he attend to the history of insects: he would find that many of them have been architects from time immemorial; that they have had their houses divided into various apartments, and containing staircases, gigantic arches, domes, colonnades, and the like; nay, that even tunnels are excavated by them so immense, compared with their own size, as to be twelve times bigger than that projected by Mr. Dodd to be carried under the Thames at Gravesend[35]. The modern fine lady, who prides herself on the lustre and beauty of the scarlet hangings which adorn the stately walls of her drawing-room, or the carpets that cover its floor, fancying that nothing so rich and splendid was ever seen before, and pitying her vulgar ancestors, who were doomed to unsightly white-wash and rushes, is ignorant all the while, that before she or her ancestors were in existence, and even before the boasted Tyrian dye was discovered, a little insect had known how to hang the walls of its cell with tapestry of a scarlet more brilliant than any her rooms can exhibit[36]; and that others daily weave silken carpets, both in tissue and texture infinitely superior to those she so much admires. No female ornament is more prized and costly than lace, the invention and fabrication of which seems the exclusive claim of the softer sex. But even here they have been anticipated by these little industrious creatures, who often defend their helpless chrysalis, by a most singular covering, and as beautiful as singular, of lace[37]. Other arts have been equally forestalled by these creatures. What vast importance is attached to the invention of paper! For near six thousand years one of our commonest insects has known how to make and apply it to its purposes[38]; and even pasteboard, superior in substance and polish to any we can produce, is manufactured by another[39]. We imagine that nothing short of human intellect can be equal to the construction of a diving-bell or an air-pump—yet a spider is in the daily habit of using the one, and, what is more, one exactly similar in principle to ours, but more ingeniously contrived; by means of which she resides unwetted in the bosom of the water, and procures the necessary supplies of air by a much more simple process than our alternating buckets[40]—and the caterpillar of a little moth knows how to imitate the other, producing a vacuum, when necessary for its purposes, without any piston besides its own body[41]. If we think with wonder of the populous cities which have employed the united labours of man for many ages to bring them to their full extent, what shall we say to the white ants, which require only a few months to build a metropolis capable of containing an infinitely greater number of inhabitants than even imperial Nineveh, Babylon, Rome, or Pekin, in all their glory?

That insects should thus have forestalled us in our inventions ought to urge us to pay a closer attention to them and their ways than we have hitherto done, since it is not at all improbable that the result would be many useful hints for the improvement of our arts and manufactures, and perhaps for some beneficial discoveries. The painter might thus probably be furnished with more brilliant pigments, the dyer with more delicate tints, and the artisan with a new and improved set of tools. In this last respect insects deserve particular notice. All their operations are performed with admirable precision and dexterity; and though they do not usually vary the mode, yet that mode is always the best that can be conceived for attaining the end in view. The instruments also with which they are provided are no less wonderful and various than the operations themselves. They have their saws, and files, and augers, and gimlets, and knives, and lancets, and scissors, and forceps, with many other similar implements; several of which act in more than one capacity, and with a complex and alternate motion to which we have not yet attained in the use of our tools. Nor is the fact so extraordinary as it may seem at first, since "He who is wise in heart and wonderful in working" is the inventor and fabricator of the apparatus of insects; which may be considered as a set of miniature patterns drawn for our use by a Divine hand. I shall hereafter give you a more detailed account of some of the most striking of these instruments; and if you study insects in this view, you will be well repaid for all the labour and attention you bestow upon them.

But a more important species of instruction than any hitherto enumerated may be derived from entomological pursuits. If we attend to the history and manners of insects, they will furnish us with many useful lessons in Ethics, and from them we may learn to improve ourselves in various virtues. We have indeed the inspired authority of the wisest of mankind for studying them in this view, since he himself wrote a treatise upon them, and sends his sluggard to one for a lesson of wisdom[42]. And if we value diligence and indefatigable industry; judgement, prudence, and foresight; economy and frugality; if we look upon modesty and diffidence as female ornaments; if we revere parental affection—of all these, and many more virtues, insects in their various instincts exhibit several striking examples, as you will see in the course of our correspondence.

With respect to religious instruction insects are far from unprofitable; indeed in this view Entomology seems to possess peculiar advantages above every other branch of Natural History. In the larger animals, though we admire the consummate art and wisdom manifested in their structure, and adore that Almighty power and goodness which by a wonderful machinery, kept in motion by the constant action and re-action of the great positive and negative powers of Nature, maintains in full force the circulations necessary to life, perception, and enjoyment; yet as there seems no disproportion between the objects and the different operations that are going on in them, and we see that they afford sufficient space for the play of their systems, we do not experience the same sensations of wonder and astonishment that strike us when we behold similar operations carried on without interruption in animals scarcely visible to the naked eye. That creatures, which in the scale of being are next to non-entities, should be elaborated with so much art and contrivance, have such a number of parts both internal and external, all so highly finished and each so nicely calculated to answer its end; that they should include in this evanescent form such a variety of organs of perception and instruments of motion, exceeding in number and peculiarity of structure those of other animals; that their nervous and respiratory systems should be so complex, their secretory and digestive vessels so various and singular, their parts of generation so clearly developed, and that these minims of nature should be endowed with instincts in many cases superior to all our boasted powers of intellect—truly these wonders and miracles declare to every one who attends to the subject, "The hand that made us is divine." We are the work of a Being infinite in power, in wisdom, and in goodness.

But no religious doctrine is more strongly established by the history of insects than that of a superintending Providence. That of the innumerable species of these beings, many of them beyond conception fragile and exposed to dangers and enemies without end, no link should be lost from the chain, but all be maintained in those relative proportions necessary for the general good of the system; that if one species for a while preponderate, and instead of preserving seem to destroy, yet counterchecks should at the same time be provided to reduce it within its due limits; and further, that the operations of insects should be so directed and overruled as to effect the purposes for which they were created and never exceed their commission: nothing can furnish a stronger proof than this, that an unseen hand holds the reins, now permitting one to prevail and now another, as shall best promote certain wise ends; and saying to each, "Hitherto shalt thou come and no further."

So complex is this mundane system, and so incessant the conflict between its component parts, an observation which holds good particularly with regard to insects, that if instead of being under such control it were left to the agency of blind chance, the whole must inevitably soon be deranged and go to ruin. Insects, in truth, are a book in which whoever reads under proper impressions cannot avoid looking from the effect to the cause, and acknowledging his eternal power and godhead thus wonderfully displayed and irrefragably demonstrated: and whoever beholds these works with the eyes of the body, must be blind indeed if he cannot, and perverse indeed if he will not, with the eye of the soul behold in all his glory the Almighty Workman, and feel disposed, with every power of his nature, to praise and magnify

"Him first, Him last, Him midst, Him without end."

And now having led you to the vestibule of an august temple, which in its inmost sanctuary exhibits enshrined in glory the symbols of the Divine Presence, I should invite you to enter and give a tongue to the Hallelujahs, which every creature in its place, by working his will with all its faculties, pours forth to its great Creator: but I must first endeavour to remove, as I trust I shall effectually, those objections to the study of these interesting beings which I alluded to in the outset of this letter, and this shall be the aim of my next address.

I am, &c.

[LETTER II.]

OBJECTIONS ANSWERED.

In my last I gave you a general view of the science of Entomology, and endeavoured to prove to you that it possesses attractions and beauty sufficient to reward any student who may profess himself its votary. I am now to consider it in a less alluring light, as a pursuit attended by no small degree of obloquy, in consequence of certain objections thought to be urged with great force against it. To obviate these, and remove every scruple from your mind, shall be the business of the present letter.

Two principal objections are usually alleged with great confidence against the study and pursuit of insects. By some they are derided as trifling and unimportant, and deemed an egregious waste of time and talents; by others they are reprobated as unfeeling and cruel, and as tending to harden the heart.

I. I shall begin with the first of these objections—that the entomologist is a mere trifler. As for the silly outcry and abuse of the ignorant vulgar, who are always ready to laugh at what they do not understand, and because insects are minute objects conclude that the study of them must be a childish pursuit, I shall not waste words upon what I so cordially despise. But since even learned men and philosophers, from a partial and prejudiced view of the subject, having recourse to this common-place logic, are sometimes disposed to regard all inquiry into these minutiæ of nature as useless and idle, and the mark of a little mind; to remove such prejudice and misconceptions I shall now dilate somewhat upon the subject of Cui bono?

When we see many wise and learned men pay attention to any particular department of science, we may naturally conclude that it is on account of some profit and instruction which they foresee may be derived from it; and therefore in defending Entomology I shall first have recourse to the Argumentum ad verecundiam, and mention the great names that have cultivated or recommended it.

We may begin the list with the first man that ever lived upon the earth, for we are told that he gave a name to every living creature[43], amongst which insects must be included; and to give an appropriate name to an object necessarily requires some knowledge of its distinguishing properties. Indeed one of the principal pleasures and employments of the paradisiacal state was probably the study of the various works of creation[44]. Before the fall the book of nature was the Bible of man, in which he could read the perfections and attributes of the invisible Godhead[45], and in it, as in a mirror, behold an image of the things of the spiritual world. Moses also appears to have been conversant with our little animals, and to have studied them with some attention. This he has shown, not only by being aware of the distinctions which separate the various tribes of grasshoppers, crickets &c. (Gryllus, L.) into different genera[46], but also by noticing the different direction of the two anterior from the four posterior legs of insects; for, as he speaks of them as going upon four legs[47], it is evident that he considered the two anterior as arms. Solomon, the wisest of mankind, made Natural History a peculiar object of study, and left treatises behind him upon its various branches, in which creeping things or insects were not overlooked[48]; and a wiser than Solomon directs our attention to natural productions, when he bids us consider the lilies of the field[49], teaching us that they are more worthy of our notice than the most glorious works of man: he also not obscurely intimates that insects are symbolical beings, when he speaks of scorpions as synonymous with evil spirits[50]; thus giving into our hands a clue for a more profitable mode of studying them, as furnishing moral and spiritual instruction.

If to these scriptural authorities we add those of uninspired writers, ancient and modern, the names of many worthies, celebrated both for wisdom and virtue, may be produced. Aristotle among the Greeks, and Pliny the elder among the Romans, may be denominated the fathers of Natural History, as well as the greatest philosophers of their day; yet both these made insects a principal object of their attention: and in more recent times, if we look abroad, what names greater than those of Redi, Malpighi, Vallisnieri, Swammerdam, Leeuwenhoek, Reaumur, Linné, De Geer, Bonnet, and the Hubers? and at home, what philosophers have done more honour to their country and to human nature than Ray, Willughby, Lister, and Derham? Yet all these made the study of insects one of their most favourite pursuits; and, as if to prove that this study is not incompatible with the highest flights of genius, we can add to the list the name of one of the most sublime of our poets, Gray, who was very zealously devoted to Entomology. As far therefore as names have weight, the above enumeration seems sufficient to shelter the votaries of this pleasing science from the charge of folly.

But we do not wish to rest our defence upon authorities alone; let the voice of reason be heard, and our justification will be complete. The entomologist, or, to speak more generally, the naturalist (for on this question of Cui bono? every student in all departments of Natural History is concerned), if the following considerations be allowed their due weight, may claim a much higher station amongst the learned than has hitherto been conceded to him.

There are two principal avenues to knowledge—the study of words and the study of things. Skill in the learned languages being often necessary to enable us to acquire knowledge in the former way, is usually considered as knowledge itself; so that no one asks Cui bono? when a person devotes himself to the study of verbal criticism, and employs his time in correcting the errors that have crept into the text of an ancient writer. Indeed it must be owned, though perhaps too much stress is sometimes laid upon it, that this is very useful to enable us to ascertain his true meaning. But after all, words are but the arbitrary signs of ideas, and have no value independent of those ideas, further than what arises from congruity and harmony, the mind being dissatisfied when an idea is expressed by inadequate words, and the ear offended when their collocation is inharmonious. To account the mere knowledge of words, therefore, as wisdom, is to mistake the cask for the wine, and the casket for the gem. I say all this because knowledge of words is often extolled beyond its just merits, and put for all wisdom; while knowledge of things, especially of the productions of nature, is derided as if it were mere folly. We should recollect that God hath condescended to instruct us by both these ways, and therefore neither of them should be depreciated. He hath set before us his word and his world. The former is the great avenue to truth and knowledge by the study of words, and, as being the immediate and authoritative revelation of his will, is entitled to our principal attention; the latter leads us to the same conclusions, though less directly, by the study of things, which stands next in rank to that of God's word, and before that of any work of man. And whether we direct our eyes to the planets rolling in their orbits, and endeavour to trace the laws by which they are guided through the vast of space, whether we analyse those powers and agents by which all the operations of nature are performed, or whether we consider the various productions of this our globe, from the mighty cedar to the microscopic mucor—from the giant elephant to the invisible mite, still we are studying the works and wonders of our God. The book, to whatever page we turn, is written by the finger of him who created us; and in it, provided our minds be rightly disposed, we may read his eternal verities. And the more accurate and enlarged our knowledge of his works, the better shall we be able to understand his word; and the more practised we are in his word, the more readily shall we discern his truth in his works; for, proceeding from the same great Author, they must, when rightly interpreted, mutually explain and illustrate each other.

Who then shall dare maintain, unless he has the hardihood to deny that God created them, that the study of insects and their ways is trifling or unprofitable? Were they not arrayed in all their beauty, and surrounded with all their wonders, and made so instrumental (as I shall hereafter prove them to be) to our welfare, that we might glorify and praise him for them? Why were insects made attractive, if not, as Ray well expresses it, that they might ornament the universe and be delightful objects of contemplation to man[51]? And is it not clear, as Dr. Paley has observed, that the production of beauty was as much in the Creator's mind in painting a butterfly or in studding a beetle, as in giving symmetry to the human frame, or graceful curves to its muscular covering[52]? And shall we think it beneath us to study what he hath not thought it beneath him to adorn and place on this great theatre of creation? Nay, shall we extol those to the skies who bring together at a vast expense the most valuable specimens of the arts, the paintings and statues of Italy and Greece, all of which, however beautiful, as works of man, fall short of perfection; and deride and upbraid those who collect, for the purpose of admiring their beauty, the finished and perfect chef-d'œuvres of a Divine artist? May we gaze with rapture unblamed upon an Apollo of Belvedere, or Venus de Medicis, or upon the exquisite paintings of a Raphael or a Titian, and yet when we behold with ecstasy sculptures that are produced by the chisel of the Almighty, and the inimitable tints laid on by his pencil, because an insect is the subject, be exposed to jeers and ridicule?

But there is another reason, which in the present age renders the study of Natural History an object of importance to every well-wisher to the cause of Religion, who is desirous of exerting his faculties in its defence. For as enthusiasm and false religion have endeavoured to maintain their ground by a perversion of the text of scripture, so also the patrons of infidelity and atheism have laboured hard to establish their impiety by a perversion of the text of nature. To refute the first of these adversaries of truth and sound religion, it is necessary to be well acquainted with the word of God; to refute the second, requires an intimate knowledge of his works; and no department can furnish him with more powerful arguments of every kind than the world of insects—every one of which cries out in an audible voice, There is a God—he is Almighty, all-wise, all-good—his watchful providence is ever, and every where, at work for the preservation of all things.

But since mankind in general are too apt to look chiefly at this world, and to regard things as important or otherwise in proportion as they are connected with sublunary interests, and promote our present welfare, I shall proceed further to prove that the study of insects may be productive of considerable utility, even in this view, and may be regarded in some sort as a necessary or at least a very useful concomitant of many arts and sciences.

The importance of insects to us both as sources of good or evil, I shall endeavour to prove at large hereafter; but for the present, taking this for granted, it necessarily follows that the study of them must also be important. For when we suffer from them, if we do not know the cause, how are we to apply a remedy that may diminish or prevent their ravages? Ignorance in this respect often occasions us to mistake our enemies for our friends, and our friends for our enemies; so that when we think to do good we only do harm, destroying the innocent and letting the guilty escape. Many such instances have occurred. You know the orange-coloured fly of the wheat, and have read the account of the damage done by this little insect to that important grain; you are aware also that it is given in charge to three little parasites to keep it within due limits; yet at first it was the general opinion of unscientific men, that these destroyers of our enemy were its parents, and the original source of all the mischief[53]. Middleton, in his "Agriculture of Middlesex," speaking of the Plant-louse that is so injurious to the bean, tells us that the lady-birds are supposed either to generate or to feed upon them[54]. Had he been an entomologist, he would have been in no doubt whether they were beneficial or injurious: on the contrary, he would have recommended that they should be encouraged as friends to man, since no insects are greater devourers of the Aphides. The confounding of the apple Aphis (A. lanigera, Myzoxyla?[55]) that has done such extensive injury to our orchards, with others, has led to proceedings still more injurious. This is one of those species from the skin of which transpires a white cottony secretion. Some of the proprietors of orchards about Evesham, observing an insect which secreted a similar substance upon the poplar, imagined that from this tree the creature which they had found so noxious was generated; and in consequence of this mistaken notion cut down all their poplars[56]. The same indistinct ideas might have induced them to fell all their larches and beeches, since they also are infested by Aphides which transpire a similar substance. Had these persons possessed any entomological knowledge, they would have examined and compared the insects before they had formed their opinions, and being convinced that the poplar and apple Aphis are distinct species, would have saved their trees.

But could an entomological observer even ascertain the species of any noxious insect, still in many cases, without further information, he may fall short of his purpose of prevention. Thus we are told that in Germany the gardeners and country people, with great industry, gather whole baskets full of the caterpillar of the destructive cabbage moth (Mamestra Brassicæ), and then bury them, which, as Roesel well observes[57], is just as if we should endeavour to kill a crab by covering it with water; for, many of them being full grown and ready to pass into their next state, which they do underground, instead of destroying them by this manœuvre, their appearing again the following year in greater numbers is actually facilitated. Yet this plan applied to our common cabbage caterpillar, which does not go underground, would succeed. So that some knowledge of the manners of an insect is often requisite to enable us to check its ravages effectually. With respect to noxious caterpillars in general, agriculturists and gardeners are not usually aware that the best mode of preventing their attacks is to destroy the female fly before she has laid her eggs, to do which the moth proceeding from each must be first ascertained. But if their research were carried still further, so as to enable them to distinguish the pupa and discover its haunts, and it would not be at all difficult to detect that of the greatest pest of our gardens, the cabbage butterfly, the work might be still more effectually accomplished. Some larvæ are polyphagous, or feed upon a variety of plants; amongst others that of the yellow-tail moth (Arctia chrysorhœa); yet gardeners think they have done enough if they destroy the web-like nests which so often deform our fruit-trees, without suspecting that new armies of assailants will wander from those on other plants which they have suffered to remain. Thus will thousands be produced in the following season, which, had they known how to distinguish them, might have been extirpated. Another instance occurred to me last year, when walking with a gentleman in his estate at a village in Yorkshire. Our attention was attracted by several circular patches of dead grass, each having a stick with rags suspended to it, placed in the centre. I at once discerned that the larva of the cock-chafer had eaten the roots of the grass, which being pulled up by the rooks that devour this mischievous grub, these birds had been mistaken by the tenant for the cause of the evil, and the rags were placed to frighten away his best friends. On inquiry why he had set up these sticks, he replied, "He could n't beer to see'd nasty craws pull up all'd gess, and sae he'd set'd bairns to hing up some aud clouts to flay 'em away. Gin he'd letten 'em alean they'd sean hev reated up all'd close." Nor could I convince him by all that I could say, that the rooks were not the cause of the evil. Even philosophers sometimes fall into gross mistakes from this species of ignorance. Dr. Darwin has observed, that destroying the beautiful but injurious woodpeckers is the only alternative for preventing the injury they do to our forest-trees by boring into them[58]; not being aware that they bore only those trees which insects have previously attacked, and that they diminish very considerably the number of such as are prejudicial to our forests.

From these facts it is sufficiently evident that entomological knowledge is necessary both to prevent fatal mistakes, and to enable us to check with effect the ravages of insects. But ignorance in this respect is not only unfit to remedy the evil; on the contrary, it may often be regarded as its cause. A large proportion of the most noxious insects in every country are not indigenous, but have been imported. It was thus that the moth (Galleria Mellonella) so destructive in bee-hives, and the asparagus beetle (Lema Asparagi) were made denizens of Sweden[59]. The insect that has destroyed all the peach-trees in St. Helena was imported from the Cape: and at home (not to mention bugs and cock-roaches) the great pest of our orchards, before mentioned, the apple Aphis, there is good reason to believe, was introduced with some foreign apple-trees. Now, extensive as is our commerce, it is next to impossible, by any precautions, to prevent the importation of these noxious agents. A cargo, or even a sample, of peas from North America might present us with that ravager of pulse, the pea-beetle (Bruchus Pisi); or the famed Hessian fly, which some years ago caused such trepidation in our cabinet, might be conveyed here in a ship-load of wheat. Leeuwenhoek's wolf (Tinea granella) might visit us, in a similar conveyance, from Holland or France. But though introduced, were Entomology a more general pursuit, their presence would soon be detected, and the evil at once nipt in the bud; whereas in a country where this science was not at all or little cultivated, they would most probably have increased to such an extent before they attracted notice, that every effort to extirpate them would be ineffectual.

It is needless to insist upon the importance of the study of insects, as calculated to throw light upon some of the obscurest points of general physiology; nor would it be difficult, though the task might be invidious, to point out how grossly incorrect and deficient are many of the speculations of our most eminent philosophers, solely from their ignorance of this important branch of Natural History. How little qualified would that physiologist be to reason conclusively upon the mysterious subject of generation, who should be ignorant of the wonderful and unlooked-for fact, brought to light by the investigations of an entomologist, that one sexual intercourse is sufficient to fertilize the eggs of numerous generations of Aphides! And how defective would be all our reasonings on the powers of nutrition and secretion, had we yet to learn that in insects both are in action unaccompanied by the circulating system and glands of larger animals!

In another point of view entomological information is very useful. A great deal of unnecessary mischief is produced, and unnecessary uneasiness occasioned, by what are called vulgar errors, and that superstitious reliance upon charms, which prevents us from having recourse to remedies that are really efficacious. Thus, for instance, eating figs and sweet things has been supposed to generate lice[60]. Nine larvæ of the moth of the wild teasel inclosed in a reed or goose quill have been reckoned a remedy for ague[61]. Matthiolus gravely affirms that every oak-gall contains either a fly, a spider, or a worm; and that the first foretells war, the second pestilence, and the third famine[62]. In Sweden the peasants look upon the grub of the cock-chafer as furnishing an unfailing prognostic whether the ensuing winter will be mild or severe; if the animal have a blueish hue (a circumstance which arises from its being replete with food) they affirm it will be mild, but on the contrary if it be white the weather will be severe: and they carry this so far as to foretell, that if the anterior part be white and the posterior blue, the cold will be most severe at the beginning of the winter. Hence they call this grub Bemärkelse-mask, or prognostic worm[63]. A similar augury as to the harvest is drawn by the Danish peasants from the mites which infest the common dung beetle (Geotrupes stercorarius), called in Danish Skarnbosse or Torbist. If there are many of these mites between the fore feet, they believe that there will be an early harvest, but a late one if they abound between the hind feet[64]. The appearance of the death's head hawk-moth (Acherontia Atropos) has in some countries produced the most violent alarm and trepidation amongst the people, who, because it emits a plaintive sound, and is marked with what looks like a death's head upon its back, regarded it as the messenger of pestilence and death[65]. We learn from Linné that a similar superstition, built upon the black hue and strange aspect of that beetle, prevails in Sweden with respect to Blaps mortisaga, L.[66]; and in Barbadoes, according to Hughes, the ignorant deem the appearance of a certain grasshopper in their houses as a sure presage of illness to some of the family[67].

One would not think that the excrements of insects could be objects of terror, yet so it has been. Many species of Lepidoptera, when they emerge from the pupa state, discharge from their anus a reddish fluid, which, in some instances, where their numbers have been considerable, has produced the appearance of a shower of blood; and by this natural fact, all those bloody showers, recorded by historians as preternatural, and regarded where they happened as fearful prognostics of impending evils, are stripped of their terrors, and reduced to the class of events that happen in the common course of nature. That insects are the cause of these showers is no recent discovery; for Sleidan relates that in the year 1553 a vast multitude of butterflies swarmed through a great part of Germany, and sprinkled plants, leaves, buildings, clothes and men, with bloody drops, as if it had rained blood[68]. But the most interesting account of an event of this kind is given by Reaumur, from whom we learn that in the beginning of July 1608 the suburbs of Aix, and a considerable extent of country round it, were covered with what appeared to be a shower of blood. We may conceive the amazement and stupor of the populace upon such a discovery, the alarm of the citizens, the grave reasonings of the learned. All agreed however in attributing this appearance to the powers of darkness, and in regarding it as the prognostic and precursor of some direful misfortune about to befall them. Fear and prejudice would have taken deep root upon this occasion, and might have produced fatal effects upon some weak minds, had not M. Peiresc, a celebrated philosopher of that place, paid attention to insects. A chrysalis which he preserved in his cabinet, let him into the secret of this mysterious shower. Hearing a fluttering, which informed him his insect was arrived at its perfect state, he opened the box in which he kept it. The animal flew out and left behind it a red spot. He compared this with the spots of the bloody shower, and found they were alike. At the same time he observed there was a prodigious quantity of butterflies flying about, and that the drops of the miraculous rain were not to be found upon the tiles, nor even upon the upper surface of the stones, but chiefly in cavities and places where rain could not easily come. Thus did this judicious observer dispel the ignorant fears and terror which a natural phenomenon had caused[69].

The same author relates an instance of the gardener of a gentleman being thrown into a horrible fright by digging up some of the curious cases, which I shall hereafter describe to you, of the leaf-cutter bees, and which he conceived to be the effect of witchcraft portending some terrible misfortune. By the advice of the priest of the parish he even took a journey from Rouen to Paris, to show them to his master: but he, happily having more sense than the man, carried them to M. Nollet, an eminent naturalist, who having seen similar productions was aware of the cause, and opening one of the cases, while the gardener stood aghast at his temerity, pointed out the grub that it contained, and thus sent him back with a light heart, relieved from all his apprehensions[70].

Every one has heard of the death-watch, and knows of the superstitious notion of the vulgar, that in whatever house its drum is heard one of the family will die before the end of the year. These terrors, in particular instances, where they lay hold of weak minds, especially of sick or hypochondriac persons, may cause the event that is supposed to be prognosticated. A small degree of entomological knowledge would relieve them from all their fears, and teach them that this heart-sickening tick is caused by a small beetle (Anobium tessellatum) which lives in timber, and is merely a call to its companion. Attention to Entomology may therefore be rendered very useful in this view, since nothing certainly is more desirable than to deliver the human mind from the dominion of superstitious fears, and false notions, which having considerable influence on the conduct of mankind are the cause of no small portion of evil.

But as we cannot well guard against the injuries produced by insects, or remove the evil, whether real or arising from misconceptions respecting them, which they occasion, unless we have some knowledge of them; so neither without such knowledge can we apply them, when beneficial, to our use. Now it is extremely probable that they might be made vastly more subservient to our advantage and profit than at present, if we were better acquainted with them. It is the remark of an author, who himself is no entomologist: "We have not taken animals enough into alliance with us. The more spiders there were in the stable, the less would the horses suffer from the flies. The great American fire-fly should be imported into Spain to catch mosquitos. In hot countries a reward should be offered to the man who could discover what insects feed upon fleas[71]." It would be worth our while to act upon this hint, and a similar one of Dr. Darwin. Those insects might be collected and preserved that are known to destroy the Aphides and other injurious tribes; and we should thus be enabled to direct their operations to any quarter where they would be most serviceable; but this can never be done till experimental agriculturists and gardeners are conversant with insects, and acquainted with their properties and economy. How is it that the Great Being of beings preserves the system which he has created from permanent injury, in consequence of the too great redundancy of any individual species, but by employing one creature to prey upon another, and so overruling and directing the instincts of all, that they may operate most where they are most wanted! We cannot better exercise the reasoning powers and faculties with which he has endowed us, than by copying his example. We often employ the larger animals to destroy each other, but the smaller, especially insects, we have totally neglected. Some may think, perhaps, that in aiming to do this we should be guilty of presumption, and of attempting to take the government and direction of things out of the hands of Providence: but this is a very weak argument, which might with equal reason be adduced to prove that when rats and mice become troublesome to us, we ought not to have recourse to dogs, ferrets, and cats to exterminate them. When any species multiplies upon us, so as to become noxious, we certainly have a just right to destroy it, and what means can be more proper than those which Providence itself has furnished? We can none of us go further or do more than the Divine Will permits; and he will take care that our efforts shall not be injurious to the general welfare, or effect the annihilation of any individual species.

Again, with regard to insects that are employed in medicine or the arts, if the apothecary cannot distinguish a Cantharis or blister-beetle from a Carabus or Cetonia, both of which beetles I have found mixed with the former, how can he know whether his druggist furnishes him with a good or bad article? And the same observation may with still greater force apply to the dyer in his purchase of cochineal, since it is still more difficult to distinguish the wild sort from the cultivated. There are, it is probable, many insects that might be employed with advantage in both these departments: but unless Entomology be more generally studied by scientific men, who are the only persons likely to make discoveries of this kind, than it has hitherto been, we must not hope to derive further profit from them. It seems more particularly incumbent upon the professors of the divine art of healing to become conversant with this as well as the other branches of Natural History; for not only do they derive some of their most useful drugs from insects, but many also of the diseases upon which they are consulted, as we shall see hereafter, are occasioned by them. For want of this kind of information medical men run the risk of confounding diseases perfectly distinct, at least as to the animal that causes them. It would be a most desirable thing to have professors in each branch of Natural History in our universities, and to make it indispensable, in order to the obtaining of any degree in Physic, that the candidate should have attended these lectures. We may judge from the good effects that the arts have derived from the present very general attention to Chemistry, how beneficial would be the consequence if Entomology were equally cultivated: and I shall conclude this paragraph with what I think may be laid down as an incontrovertible axiom:—That the profit we derive from the works of creation will be in proportion to the accuracy of our knowledge of them and their properties.

I trust I have now said enough to convince you and every thinking man that the study of insects, so far from being vain, idle, trifling, or unprofitable, may be attended with very important advantages to mankind, and ought at least to be placed upon a level with many other branches of science, against which such accusations are never alleged.

But I must not conceal from you that there are objectors who will still return to the charge. They will say, "We admit that the pursuits of the entomologist are important when he directs his views to the destruction of noxious insects; the discovery of new ones likely to prove beneficial to man; and to practical experiments upon their medical and economical properties. But where are the entomologists that in fact pursue this course? Do they not in reality wholly disregard the economical department of their science, and content themselves with making as large a collection of species as possible; ascertaining the names of such as are already described; describing new ones; and arranging the whole in their cabinets under certain families and genera? And can a study with these sole ends in view deserve a better epithet than trifling? Even if the entomologist advance a step further, and invent a new system for the distribution of all known insects, can his laborious undertaking be deemed any other than busy idleness? What advantage does the world derive from having names given to ten or twenty thousand insects, of which numbers are not bigger than a pin's head, and of which probably not a hundredth part will ever be of any use to mankind?"

Now in answer to this supposed objection, which I have stated as forcibly as I am able, and which, as it may be, and often is, urged against every branch of Natural History as at present studied, well deserves a full consideration, I might in the first place deny that those who have the highest claim to rank as entomologists do confine their views to the systematic department of the science to the neglect of economical observations; and in proof of my assertion, I might refer abroad to a Linné, a Reaumur, a De Geer, a Huber, and various other names of the highest reputation; and at home to a Ray, a Lister, a Derham, a Marsham, a Curtis, a Clark, a Roxburgh, &c. But I do not wish to conceal that though a large proportion of entomologists direct their views much further than to the mere nomenclature of their science, there exists a great number, probably the majority, to whom the objection will strictly apply. Now I contend, and shall next endeavour to prove, that entomologists of this description are devoting their time to a most valuable end; and are conferring upon society a benefit incalculably greater than that derived from the labours of many of those who assume the privilege of despising their pursuit.

Even in favour of the mere butterfly-hunter—he who has no higher aim than that of collecting a picture of Lepidoptera, and is attached to insects solely by their beauty or singularity, it would not be difficult to say much. Can it be necessary to declaim on the superiority of a people amongst whom intellectual pleasures, however trifling, are preferred to mere animal gratifications? Is it a thing to be lamented that some of the Spitalfields weavers occupy their leisure hours in searching for the Adonis butterfly (Polyommatus Adonis), and others of the more splendid Lepidoptera[72], instead of spending them in playing at skittles or in an alehouse? Or is there in truth any thing more to be wished than that the cutlers of Sheffield were accustomed thus to employ their Saint Mondays; and to recreate themselves after a hard day's work, by breathing the pure air of their surrounding hills, while in search of this "untaxed and undisputed game[73];" and that more of the Norwich weavers were fond of devoting their vacant time to plant-hunting, like Joseph Fox recorded by Sir James Smith as the first raiser of a Lycopodium from seed[74]?

Still more easy is it to advocate the cause of another description of entomologists—the general collectors. These, though not concerning themselves with the system, contribute most essentially to its advancement. We cannot expect that princes, noblemen, and others of high rank or large fortune, who collect insects, should be able or willing to give up the time necessary for studying them systematically: but their museums being accessible to the learned entomologist afford him the use of treasures which his own limited funds or opportunities could never have brought together. As to others of less consequence that content themselves with the title of collectors, they also have their use. Having devoted themselves to this one department, they become more expert at it, than the philosopher who combines deep researches with the collection of objects; and thus are many species brought together for the use of the systematist, that would otherwise remain unknown.

But to proceed to the defence of systematic entomologists.—These may be divided into two great classes: the first comprising those who confine themselves to ascertaining the names of the insects they collect; the second, those who, in addition, publish descriptions of new species; new arrangements of intricate genera; or extrications of entangled synonyms; and who, in other respects, actively contribute to the perfection of the system.

Now with regard to the first class, setting aside what may be urged in behalf of the study of insects considered as the work of the Creator, it is easy to show that, even with such restricted views, their pursuit is as commendable, and as useful both to themselves and the community, as many of those on which we look with the greatest respect. To say the least in their favour, they amuse themselves innocently, which is quite as much as can be urged for persons who recreate their leisure hours with music, painting, or desultory reading. They furnish themselves with an unfailing provision of that "grand panacea for the tædium vitæ"—employment—no unimportant acquisition, when even Gray was forced to exclaim, with reference to the necessity of "always having something going forward" towards the enjoyment of life, "Happy they who can create a rose-tree or erect a honey-suckle; that can watch the brood of a hen, or see a fleet of their own ducklings launch into the water[75]!" and like the preceding class, they collect valuable materials for the use of more active labourers, being thus at least upon a par with the majority of book-collectors and antiquaries.

But this is the smallest half of the value of their pursuit. With what view is the study of the mathematics so generally recommended? Not certainly for any practical purpose—not to make the bulk of those who attend to them, astronomers or engineers. But simply to exercise and strengthen the intellect—to give the mind a habit of attention and of investigation. Now for all these purposes, if I do not go so far as to assert that the mere ascertaining of the names of insects is equal to the study of the mathematics, I have no hesitation in affirming that it is nearly as effectual; and with respect to giving a habit of minute attention, superior. Such is the intricacy of nature, such the imperfection of our present arrangements, that the discovery of the name of almost any insect is a problem, calling in all cases for acuteness and attention, and in some for a balancing of evidence, a calculation of the chances of error, as arduous as are required in a perplexed law-case; and a process of ratiocination not less strict than that which satisfies the mathematician. In proof of which assertion I need only refer any competent judge to the elaborate disquisitions of Laspeyres, called for by one work alone on the lepidopterous insects of a single district—the Wiener Verzeichniss, which occupy above two hundred octavo pages[76], and must have cost the learned author nearly as much labour of mind as the Ductor Dubitantium did Bishop Taylor.

Do not apprehend that this occasional perplexity is any deduction from the attractions of the science: though in itself, in some respects, an evil, it forms in fact to many minds one of the chief of them. The pursuit of truth, in whatever path, affords pleasure: but the interest would cease if she never gave us trouble in the chase. Horace Walpole used to say that from a child he could never bring himself to attend to any book that was not full of proper names; and the satisfaction which he felt in dry investigations concerning noble authors and obscure painters, is experienced by many an entomologist who spends hours in disentangling the synonymy of a doubtful species. Nor would it be easy to prove that the wordy researches of the one are not to every practical purpose as valuable as those of the other. We smile at the Frenchman told of by Menage, that was so enraptured with the study of heraldry and genealogy, as to lament the hard case of our forefather Adam, who could not possibly amuse himself with such investigations[77]. But many an entomologist who has felt the delicious sensation attendant upon the indisputable ascertainment of an insect's name after a long search, will feel inclined to indulge in similar grief for the unhappy lot of his successors, when all shall be smooth sailing in the science.

But in behalf of those who are more eminently entitled to be called entomologists—those who, not content with collecting and investigating insects, occupy themselves in naming and describing such as have been before unobserved; in instituting new genera or reforming the old; and, to say all in one word, in perfecting the system of the science, still higher claims can be urged. Suppose that at this moment our dictionaries of the French and German languages were so very defective, that we were unable by the use of them to profit from the discoveries of their philosophers; the labours of a Michaelis being a sealed book to our theologists, and those of La Place to our astronomers. On this supposition, would not one of the most important literary undertakings be the compilation of more perfect dictionaries, and would not the humblest contributor to such an end be deemed most meritoriously engaged? Now precisely what an accurate dictionary of a particular language is towards enabling the world to participate in the discoveries published in that language, is a system of Entomology towards enabling mankind to derive advantage from any discoveries relative to insects. A good system of insects containing all the known species, arranged in appropriate genera, families, orders and classes, is in fact a dictionary, putting it within our power to ascertain the name of any given insect, and thus to learn what has been observed respecting its properties and history as readily as we determine the meaning of a new word in a lexicon. In order to impress upon you more forcibly the absolute need of such a system, I must enter into still further detail.

There is scarcely a country in which several thousand insects may not be found. Now, without some scientific arrangement, how is the observer of a new fact respecting any one of them, to point out to distant countries and to posterity the particular insect he had in view? Suppose an observer in England were to find a certain beetle which he had demonstrated to be a specific for consumption; and that it was necessary that this insect, which there was reason to believe was common in every part of the world, should be administered in a recent state. Would he not be anxious to proclaim the happy discovery to sufferers in all quarters of the globe? As his remedy would not admit of transportation, he would have no other means than by describing it. Now the question is, whether, on the supposition that no system of Entomology existed, he would be able to do this, so as to be intelligible to a physician in North America, for instance, eager to administer so precious a medicine to his expiring patient? It would evidently be of no use to say that the specific was a beetle: there are thousands of different beetles in North America. Nor would size or colour be any better guide: there are hundreds of beetles of the same size and the same colour. Even the plant on which it fed would be no sufficient clue; for many insects, resembling each other to an unpractised eye, feed on the same plant; and the same insect in different countries feeds upon different plants. His only resource, then, would be a coloured figure and full description of it. But every entomologist knows that there exist insects perfectly distinct, yet so nearly resembling each other, that no engraving, nor any language other than that strictly scientific, can possibly discriminate them. After all, therefore, the chances are, that our discoverer's remedy, invaluable as it might be, must be confined to his own immediate neighbourhood, or to those who came to receive personal information from him. But with what ease is it made known when a system of the science exists! If the insect be already described, he has but to mention its generic and trivial names, and by aid of two words alone, every entomologist, though in the most distant region—whether a Swede, a German, or a Frenchman; whether a native of Europe, of Asia, of America, or of Africa, knows instantly the very species that is meant, and can that moment ascertain whether it be within his reach. If the species be new and undescribed, it is only necessary to indicate the genus to which it belongs, the species to which it is most nearly allied, and to describe it in scientific terms, which may be done in few words, and it can at once be recognised by every one acquainted with the science.

You will think it hardly credible that there should be so much difficulty in describing an insect intelligibly without the aid of system; but an argumentum ad hominem, supported by some other facts, will, I conjecture, render this matter more comprehensible. You have doubtless, like every one else, in the showery days of summer, felt no little rage at the flies, which at such times take the liberty of biting our legs, and contrive to make a comfortable meal through the interstices of their silken or cotton coverings. Did it, I pray, ever enter into your conception, that these blood-thirsty tormentors are a different species from those flies which you are wont to see extending the lips of their little proboscis to a piece of sugar or a drop of wine? I dare say not. But the next time you have sacrificed one of the former to your just vengeance, catch one of the latter and compare them. I question if, after the narrowest comparison, you will not still venture a wager that they are the very same species. Yet you would most certainly lose your bet. They are not even of the same genus—one belonging to the genus Musca (M. domestica), and the other to the genus Stomoxys (S. calcitrans); and on a second examination you will find that, however alike in most respects, they differ widely in the shape of their proboscis; that of the Stomoxys being a horny sharp-pointed weapon, capable of piercing the flesh, while the soft blunt organ of the Musca is perfectly incompetent to any such operation. In future, while you no longer load the whole race of the house-fly with the execrations which properly belong to a quite different tribe, you will cease being surprised that an ordinary description should be insufficient to discriminate an insect. It is to this insufficiency that we must attribute our ignorance of so many of the insects mentioned by the older naturalists, previously to the systematic improvements of the immortal Linné: and to the same cause we must refer the impossibility of determining what species are alluded to in the accounts of many modern travellers and agriculturists who have been ignorant of Entomology as a science. Instances without number of this impossibility might be adduced, but I shall confine myself to two.

One of the greatest pests of Surinam and other low regions in South America, is the insect called in the West Indies, where it is also troublesome, the chigoe (Pulex penetrans), a minute species, to the attacks of which I shall again have occasion to advert. This insect is mentioned by almost all the writers on the countries where it is found. Not less than eight or ten of them have endeavoured to give a full description of it, and some of them have even figured it; and yet, strange to say, it was not certainly known whether it was a flea (Pulex, L.) or a mite (Acarus, L.), till a competent naturalist undertook to investigate its history, and in a short paper in the Swedish Transactions[78] proved that Linné was not mistaken in referring it to the former tribe.

The second instance of the insufficiency of popular description is even more extraordinary. In 1788 an alarm was excited in this country by the probability of importing, in cargoes of wheat from North America, the insect known by the name of the Hessian fly, whose dreadful ravages will be adverted to hereafter. However the insect tribes are in general despised, they had on that occasion ample revenge. The privy council sat day after day anxiously debating what measures should be adopted to ward off the danger of a calamity, more to be dreaded, as they well knew, than the plague or pestilence. Expresses were sent off in all directions to the officers of the customs at the different outports respecting the examination of cargoes—dispatches written to the ambassadors in France, Austria, Prussia, and America, to gain that information of the want of which they were now so sensible: and so important was the business deemed, that the minutes of council and the documents collected from all quarters fill upwards of two hundred octavo pages[79]. Fortunately England contained one illustrious naturalist, the most authentic source of information on all subjects which connect Natural History with Agriculture and the Arts, to whom the privy council had the wisdom to apply; and it was by Sir Joseph Banks's entomological knowledge, and through his suggestions, that they were at length enabled to form some kind of judgement on the subject. This judgement was after all, however, very imperfect. As Sir Joseph Banks had never seen the Hessian fly, nor was it described in any entomological system, he called for facts respecting its nature, propagation, and economy, which could be had only from America. These were obtained as speedily as possible, and consist of numerous letters from individuals; essays from magazines; the reports of the British minister there, &c. &c. One would have supposed that from these statements, many of them drawn up by farmers who had lost entire crops by the insect, which they profess to have examined in every stage, the requisite information might have been acquired. So far however was this from being the case, that many of the writers seem ignorant whether the insect be a moth, a fly, or what they term a bug. And though from the concurrent testimony of several its being a two-winged fly seemed pretty accurately ascertained, no intelligible description is given, from which any naturalist can infer to what genus it belongs, or whether it is a known species. With regard to the history of its propagation and economy the statements were so various and contradictory, that though he had such a mass of materials before him, Sir Joseph Banks was unable to reach any satisfactory conclusion.

Nothing can more incontrovertibly demonstrate the importance of studying Entomology as a science than this fact. Those observations, to which thousands of unscientific sufferers proved themselves incompetent, would have been readily made by one entomologist well versed in his science. He would at once have determined the order and genus of the insect, and whether it was a known or new species; and in a twelvemonth at furthest he would have ascertained in what manner it made its attacks, and whether it were possible that it might be transmitted along with grain into a foreign country; and on these solid data he could have satisfactorily pointed out the best mode of eradicating the pest, or preventing the extension of its ravages.

But it is not merely in travellers and popular observers that the want of a systematic knowledge of Entomology is so deplorable. A great portion of the labours of the profoundest naturalists has been from a similar cause lost to the world. Many of the insects concerning which Reaumur and Bonnet have recorded the most interesting circumstances, cannot, from their neglect of system, be at this day ascertained[80]. The former, as Beckmann[81] states on the authority of his letters, was before his death sensible of his great error in this respect: but Bonnet, with singular inconsistency, constantly maintained the inutility of system, even on an occasion when, from his ignorance of it, Sir James Smith, speaking of his experiments on the barberry, found it quite impossible to make him comprehend what plant he referred to[82].

So great is the importance of a systematic arrangement of insects. Yet no such arrangement has hitherto been completed. Various fragments towards it indeed exist. But the work itself is in the state of a dictionary wanting a considerable proportion of the words of the language it professes to explain; and placing those, which it does contain, in an order often so arbitrary and defective, that it is difficult to discover even the page containing the word you are in search of. Can it be denied, then, that they are most meritoriously employed who devote themselves to the removal of these defects—to the perfecting of the system—and to clearing the path of future economical or physiological observers from the obstructions which now beset it? And who that knows the vast extent of the science, and how impossible it is that a divided attention can embrace the whole, will contend that it is not desirable that some labourers in the field of literature should devote themselves entirely and exclusively to this object? Who that is aware of the importance of the comprehensive views of a Fabricius, an Illiger, or a Latreille, and the infinite saving of time of which their inquiries will be productive to their followers, will dispute their claim to rank amongst the most honourable in science?

II. No objection, I think, now remains against addicting ourselves to entomological pursuits, but that which seems to have the most weight with you, and which indeed is calculated to make the deepest impression upon the best minds—I mean the charge of inhumanity and cruelty. That the science of Entomology cannot be properly cultivated without the death of its objects, and that this is not to be effected without putting them to some pain, must be allowed; but that this substantiates the charge of cruelty against us I altogether deny. Cruelty is an unnecessary infliction of suffering, when a person is fond of torturing or destroying God's creatures from mere wantonness, with no useful end in view; or when, if their death be useful and lawful, he has recourse to circuitous modes of killing them, where direct ones would answer equally well. This is cruelty, and this with you I abominate; but not the infliction of death when a just occasion calls for it.

They who see no cruelty in the sports of the field, as they are called, can never, of course, consistently allege such a charge against the entomologist; the tortures of wounded birds, of fish that swallow the hook and break the line, or of the hunted hare, being, beyond comparison, greater than those of insects destroyed in the usual mode. With respect to utility, the sportsman, who, though he adds indeed to the general stock of food, makes amusement his primary object, must surely yield the palm to the Entomologist, who adds to the general stock of mental food, often supplies hints for useful improvements in the arts and sciences, and the objects of whose pursuit, unlike those of the former, are preserved and may be applied to use for many years.

But in the view even of those few who think inhumanity chargeable upon the sportsman, it will be easy to place considerations which may rescue the entomologist from such reproof. It is well known that, in proportion as we descend in the scale of being, the sensibility of the objects that constitute it diminishes. The tortoise walks about after losing its head; and the polypus, so far from being injured by the application of the knife, thereby acquires an extension of existence. Insensibility almost equally great may be found in the insect world. This, indeed, might be inferred à priori, since Providence seems to have been more prodigal of insect life than of that of any other order of creatures, animalcula perhaps alone excepted. No part of the creation is exposed to the attack of so many enemies, or subject to so many disasters; so that the few individuals of each kind which enrich the valued museum of the entomologist, many of which are dearer to him than gold or gems, are snatched from the ravenous maw of some bird or fish or rapacious insect; would have been driven by the winds into the waters and drowned; or trodden underfoot by man or beast,—for it is not easy, in some parts of the year, to set foot to the ground without crushing these minute animals; and thus also, instead of being buried in oblivion, they have a kind of immortality conferred upon them. Can it be believed that the beneficent Creator, whose tender mercies are over all his works, would expose these helpless beings to such innumerable enemies and injuries, were they endued with the same sense of pain and irritability of nerve with the higher orders of animals?

But this inference is reduced to certainty, when we attend to the facts which insects every day present to us, proving that the very converse of our great poet's conclusion, as usually interpreted,

... The poor beetle that we tread upon,
In corporal sufferance finds a pang as great
As when a giant dies,

must be regarded as nearer the truth[83]. Not to mention the peculiar organization of insects, which strongly favours the idea I am inculcating, but which will be considered more properly in another place, their sang-froid upon the loss of their limbs, even those that we account most necessary to life, irrefragably proves that the pain they suffer cannot be very acute. Had a giant lost an arm or a leg, or were a sword or spear run through his body, he would feel no great inclination for running about, dancing, or eating. Yet a crane-fly (Tipula) will leave half its legs in the hands of an unlucky boy who has endeavoured to catch it, and will fly here and there with as much agility and unconcern as if nothing had happened to it; and an insect impaled upon a pin will often devour its prey with as much avidity as when at liberty. Were a giant eviscerated, his body divided in the middle, or his head cut off, it would be all over with him; he would move no more; he would be dead to the calls of hunger; or the emotions of fear, anger, or love. Not so our insects. I have seen the common cock-chafer walk about with apparent indifference after some bird had nearly emptied its body of its viscera: a humble-bee will eat honey with greediness though deprived of its abdomen; and I myself lately saw an ant, which had been brought out of the nest by its comrades, walk when deprived of its head. The head of a wasp will attempt to bite after it is separated from the rest of the body; and the abdomen under similar circumstances, if the finger be moved to it, will attempt to sting. And, what is more extraordinary, the headless trunk of a male Mantis has been known to unite itself to the other sex[84]. These facts, out of hundreds that might be adduced, are surely sufficient to prove that insects do not experience the same acute sensations of pain with the higher orders of animals, which Providence has endowed with more ample means of avoiding them; and since they were to be exposed so universally to attack and injury, this is a most merciful provision in their favour; for, were it otherwise, considering the wounds, and dismemberments, and lingering deaths that insects often suffer, what a vast increase would there be of the general sum of pain and misery! You will now, I think, allow that the most humane person need not hesitate a moment, whether he shall devote himself to the study of Entomology, on account of any cruelty attached to the pursuit.

But if some morbid sentimentalist should still exclaim, "Oh! but I cannot persuade myself even for scientific purposes to inflict the slightest degree of pain upon the most insensible of creatures—" Pray, sir or madam, I would ask, should your green-house be infested by Aphides, or your grapery by the semianimate Coccus, would this extreme of tenderness induce you to restrict your gardener from destroying them? Are you willing to deny yourself these unnecessary gratifications, and to resign your favourite flowers and fruit at the call of your fine feelings? Or will you give up the shrimps, which by their relish enable you to play a better part with your bread and butter at breakfast, and thus, instead of adding to it, contribute to diminish the quantity of food? If not, I shall only desire you to recollect that, for a mere personal indulgence, you cause the death of an infinitely greater number of animals, than all the entomologists in the world destroy for the promotion of science.

To these considerations, which I have no doubt you will think conclusive as to the unreasonableness and inconsistency of the objections made against the study of Entomology on the score of cruelty, I shall only add that I do not intend them as any apology for other than the most speedy and least painful modes of destroying insects; and these will be pointed out to you in a subsequent letter. Every degree of unnecessary pain becomes cruelty, which I need not assure you I abhor; and from my own observations, however ruthlessly the entomologist may seem to devote the few specimens wanted for scientific purposes to destruction, no one in ordinary circumstances is less prodigal of insect life. For my own part, I question whether the drowning individuals, which I have saved from destruction, would not far outnumber all that I ever sacrificed to science.

My next letter will be devoted to the metamorphoses of insects, a subject on which some previous explanation is necessary to enable you to understand those distinctions between their different states, which will be perpetually alluded to in the course of our correspondence: and having thus cleared the way, I shall afterwards proceed to the consideration of the injuries and benefits of which insects are the cause.

I am, &c.

[LETTER III.]

METAMORPHOSES OF INSECTS.

Were a naturalist to announce to the world the discovery of an animal which for the first five years of its life existed in the form of a serpent; which then penetrating into the earth, and weaving a shroud of pure silk of the finest texture, contracted itself within this covering into a body without external mouth or limbs, and resembling more than any thing else an Egyptian mummy; and which, lastly, after remaining in this state without food and without motion for three years longer, should at the end of that period burst its silken cerements, struggle through its earthy covering, and start into day a winged bird,—what think you would be the sensation excited by this strange piece of intelligence? After the first doubts of its truth were dispelled, what astonishment would succeed! Amongst the learned, what surmises!—what investigations! Amongst the vulgar, what eager curiosity and amazement! All would be interested in the history of such an unheard-of phenomenon; even the most torpid would flock to the sight of such a prodigy.

But you ask, "To what do all these improbable suppositions tend?" Simply to rouse your attention to the metamorphoses of the insect world, almost as strange and surprising, to which I am now about to direct your view,—miracles, which, though scarcely surpassed in singularity by all that poets have feigned, and though actually wrought every day beneath our eyes, are, because of their commonness, and the minuteness of the objects, unheeded alike by the ignorant and the learned.

That butterfly which amuses you with its aërial excursions, one while extracting nectar from the tube of the honeysuckle, and then, the very image of fickleness, flying to a rose as if to contrast the hue of its wings with that of the flower on which it reposes—did not come into the world as you now behold it. At its first exclusion from the egg, and for some months of its existence afterwards, it was a worm-like caterpillar, crawling upon sixteen short legs, greedily devouring leaves with two jaws, and seeing by means of twelve eyes so minute as to be nearly imperceptible without the aid of a microscope. You now view it furnished with wings capable of rapid and extensive flights: of its sixteen feet ten have disappeared, and the remaining six are in most respects wholly unlike those to which they have succeeded; its jaws have vanished, and are replaced by a curled-up proboscis suited only for sipping liquid sweets; the form of its head is entirely changed,—two long horns project from its upper surface; and, instead of twelve invisible eyes, you behold two, very large, and composed of at least twenty thousand convex lenses, each supposed to be a distinct and effective eye!

Were you to push your examination further, and by dissection to compare the internal conformation of the caterpillar with that of the butterfly, you would witness changes even more extraordinary. In the former you would find some thousands of muscles, which in the latter are replaced by others of a form and structure entirely different. Nearly the whole body of the caterpillar is occupied by a capacious stomach. In the butterfly this has become converted into an almost imperceptible thread-like viscus; and the abdomen is now filled by two large packets of eggs, or other organs not visible in the first state. In the former, two spirally-convoluted tubes were filled with a silky gum; in the latter, both tubes and silk have almost totally vanished; and changes equally great have taken place in the economy and structure of the nerves and other organs.

What a surprising transformation! Nor was this all. The change from one form to the other was not direct. An intermediate state not less singular intervened. After casting its skin even to its very jaws several times, and attaining its full growth, the caterpillar attached itself to a leaf by a silken girth. Its body greatly contracted: its skin once more split asunder, and disclosed an oviform mass, without exterior mouth, eyes, or limbs, and exhibiting no other symptom of life than a slight motion when touched. In this state of death-like torpor, and without tasting food, the insect existed for several months, until at length the tomb burst, and out of a case not more than an inch long, and a quarter of an inch in diameter, proceeded the butterfly before you, which covers a surface of nearly four inches square.

Almost every insect which you see has undergone a transformation as singular and surprising, though varied in many of its circumstances. That active little fly, now an unbidden guest at your table[85], whose delicate palate selects your choicest viands, one while extending his proboscis to the margin of a drop of wine, and then gaily flying to take a more solid repast from a pear or a peach; now gamboling with his comrades in the air, now gracefully currying his furled wings with his taper feet,—was but the other day a disgusting grub, without wings, without legs, without eyes, wallowing, well pleased, in the midst of a mass of excrement.

The "grey-coated gnat," whose humming salutation, while she makes her airy circles about your bed, gives terrific warning of the sanguinary operation in which she is ready to engage, was a few hours ago the inhabitant of a stagnant pool, more in shape like a fish than an insect. Then to have been taken out of the water would have been speedily fatal; now it could as little exist in any other element than air. Then it breathed through its tail; now through openings in its sides. Its shapeless head, in that period of its existence, is now exchanged for one adorned with elegantly tufted antennæ, and furnished, instead of jaws, with an apparatus more artfully constructed than the cupping-glasses of the phlebotomist—an apparatus which, at the same time that it strikes in the lancets, composes a tube for pumping up the flowing blood.

The "shard-born beetle," whose "sullen horn," as he directs his "droning flight" close past your ears in your evening walk, calling up in poetic association the lines in which he has been alluded to by Shakespear, Collins, and Gray, was not in his infancy an inhabitant of air; the first period of his life being spent in gloomy solitude, as a grub, under the surface of the earth.—The shapeless maggot, which you scarcely fail to meet with in some one of every handful of nuts you crack, would not always have grovelled in that humble state. If your unlucky intrusion upon its vaulted dwelling had not left it to perish in the wide world, it would have continued to reside there until its full growth had been attained. Then it would have gnawed itself an opening, and having entered the earth, and passed a few months in a state of inaction, would at length have emerged an elegant beetle furnished with a slender and very long ebony beak: two wings, and two wing-cases, ornamented with yellow bands; six feet; and in every respect unlike the worm from which it proceeded.

That bee—but it is needless to multiply instances. A sufficient number has been adduced to show, that the apparently extravagant supposition with which I set out may be paralleled in the insect world; and that the metamorphoses of its inhabitants are scarcely less astonishing than would be the transformation of a serpent into an eagle.

These changes I do not purpose explaining minutely in this place: they will be adverted to more fully in subsequent letters. Here I mean merely to give you such a general view of the subject as shall impress you with its claims to attention, and such an explanation of the states through which insects pass, and of the different terms made use of to designate them in each, as shall enable you to comprehend the frequent allusions which must be made to them in our future correspondence.

The states through which insects pass are four: the egg; the larva; the pupa; and the imago.

The first of these need not be here adverted to. In the second, or immediately after the exclusion from the egg, they are soft, without wings, and in shape usually somewhat like worms. This Linné called the larva state, and an insect when in it a larva, adopting a Latin word signifying a mask, because he considered the real insect while under this form to be as it were masked. In the English language we have no common term that applies to the second state of all insects, though we have several for that of different tribes. Thus we call the coloured and often hairy larvæ of butterflies and moths caterpillars; the white and more compact larvæ of flies, many beetles, &c. grubs or maggots[86]; and the depressed larvæ of many other insects worms. The two former terms I shall sometimes use in a similar sense, rejecting the last, which ought to be confined to true vermes; but I shall more commonly adopt Linné's term, and call insects in their second state, larvæ[87].

In this period of their life, during which they eat voraciously and cast their skin several times, insects live a shorter or longer period, some only a few days or weeks, others several months or years. They then cease eating; fix themselves in a secure place; their skin separates once more and discloses an oblong body, and they have now attained the third state of their existence.

From the swathed appearance of most insects in this state, in which they do not badly resemble in miniature a child trussed up like a mummy in swaddling clothes, according to the barbarous fashion once prevalent here, and still retained in many parts of the continent; Linné has called it the pupa state, and an insect when under this form a pupa;—terms which will be here adopted in the same sense. In this state, most insects eat no food; are incapable of locomotion; and if opened seem filled with a watery fluid, in which no distinct organs can be traced. Externally, however, the shape of the pupæ of different tribes varies considerably, and different names have been applied to them.

Those of the beetle and bee tribes are covered with a membranous skin, inclosing in separate and distinct sheaths the external organs, as the antennæ, legs, and wings, which are consequently not closely applied to the body, but have their form for the most part clearly distinguishable. To these Aristotle originally gave the name of nymphæ[88], which was continued by Swammerdam and other authors prior to Linné, who calls them incomplete pupæ, and has been adopted by many English writers on insects[89].

Butterflies, moths, and some of the two-winged tribe, are in their pupa state also inclosed in a similar membranous envelope; but their legs, antennæ, and wings, are closely folded over the breast and sides; and the whole body inclosed in a common case or covering of a more horny consistence, which admits a much less distinct view of the organs beneath it. As these pupæ are often tinged of a golden colour, they were called from this circumstance chrysalides by the Greeks, and aureliæ by the Romans, both which terms are in some measure become anglicized; and though not strictly applicable to ungilded pupæ, are now often given to those of all lepidopterous insects[90]. These by Linné are denominated obtected pupæ[91].

I have said that most insects eat no food in the pupa state. This qualification is necessary, because in the metamorphoses of insects, as in all her other operations, nature proceeds by measured steps, and a very considerable number (the tribe of locusts, cockroaches, bugs, spiders, &c.) not only greatly resemble the perfect insect in form, but are equally capable with it of eating and moving. As these insects, however, cast their skins at stated periods, and undergo changes, though slight, in their external and internal conformation, they are regarded also as being subject to metamorphoses. These pupæ may be subdivided into two classes: first, those comprised, with some exceptions, under the Linnean Aptera, which in almost every respect resemble the perfect insect, and were called by Linné complete pupæ; and secondly, those of the Linnean order Hemiptera, which resemble the perfect insect, except in having only the rudiments of wings, and to which the name of semi-complete pupæ was applied by Linné, and that of semi-nymphs by some other authors[92]. There is still a fifth kind of pupæ, which are not, as in other instances, excluded from the skin of the larva, but remain concealed under it, and were hence called by Linné coarctate pupæ. These, which are peculiar to flies and some other dipterous genera, may be termed cased-nymphs[93].

When, therefore, we employ the term pupa, we may refer indifferently to the third state of any insect, the particular order being indicated by the context, or an explanatory epithet. The terms chrysalis, (dropping aurelia, which is superfluous,) nymph, semi-nymph, and cased-nymph, on the other hand definitely pointing out the particular sort of pupa meant: just as in Botany, the common term pericarp applies to all seed-vessels, the several kinds being designated by the names of capsule, silicle, &c.

The envelope of cased-nymphs, which is formed of the skin of the larva, considerably altered in form and texture, may be conveniently called the puparium[94]: but to the artificial coverings of different kinds, whether of silk, wood, or earth, &c. which many insects of the other orders fabricate for themselves previously to assuming the pupa state, and which have been called by different writers, pods, cods, husks, and beans, I shall continue the more definite French term cocon, anglicized into cocoon[95].

After remaining a shorter or longer period, some species only a few hours, others months, others one or more years, in the pupa state, the inclosed insect, now become mature in all its parts, bursts the case which inclosed it, quits the pupa, and enters upon the fourth and last state.

We now see it (unless it be an apterous species) furnished with wings, capable of propagation, and often under a form altogether different from those which it has previously borne—a perfect beetle, butterfly, or other insect. This Linné termed the imago state, and the animal that had attained to it the imago; because, having laid aside its mask, and cast off its swaddling bands, being no longer disguised or confined, or in any respect imperfect, it is now become a true representative or image of its species. This state is in general referred to when an insect is spoken of without the restricting terms larva or pupa.

Such being the singularity of the transformations of insects, you will not think the ancients were so wholly unprovided with a show of argument as we are accustomed to consider them, for their belief in the possibility of many of the marvellous metamorphoses which their poets recount. Utterly ignorant as they were of modern physiological discoveries, the conversion of a caterpillar into a butterfly, must have been a fact sufficient to put to a nonplus all the sceptical oppugners of such transformations. And however we may smile in this enlightened age at the inference drawn not two centuries ago by Sir Theodore Mayerne, the editor of Mouffet's work on insects, "that if animals are transmuted so may metals[96]," it was not, in fact, with his limited knowledge on these subjects, so very preposterous. It is even possible that some of the wonderful tales of the ancients were grafted on the changes which they observed to take place in insects. The death and revivification of the phœnix, from the ashes of which, before attaining its perfect state, arose first a worm (σκωληξ), in many of its particulars resembles what occurs in the metamorphoses of insects. Nor is it very unlikely that the doctrine of the metempsychosis took its rise from the same source. What argument would be thought by those who maintained this doctrine more plausible in favour of the transmigration of souls, than the seeming revivification of the dead chrysalis? What more probable, than that its apparent reassumption of life should be owing to its receiving for tenant the soul of some criminal doomed to animate an insect of similar habits with those which had defiled his human tenement[97]?

At the present day, however, the transformations of insects have lost that excess of the marvellous, which might once have furnished arguments for the fictions of the ancients, and the dreams of Paracelsus. We call them metamorphoses and transformations, because these terms are in common use, and are more expressive of the sudden changes that ensue than any new ones. But, strictly, they ought rather to be termed a series of developments. A caterpillar is not, in fact, a simple but a compound animal, containing within it the germ of the future butterfly, inclosed in what will be the case of the pupa, which is itself included in the three or more skins, one over the other, that will successively cover the larva. As this increases in size these parts expand, present themselves, and are in turn thrown off, until at length the perfect insect, which had been concealed in this succession of masks, is displayed in its genuine form. That this is the proper explanation of the phenomenon has been satisfactorily proved by Swammerdam, Malpighi, and other anatomists. The first-mentioned illustrious naturalist discovered, by accurate dissections, not only the skins of the larva and of the pupa incased in each other, but within them the very butterfly itself, with its organs indeed in an almost fluid state, but still perfect in all its parts[98]. Of this fact you may convince yourself without Swammerdam's skill, by plunging into vinegar or spirit of wine a caterpillar about to assume the pupa state, and letting it remain there a few days for the purpose of giving consistency to its parts; or by boiling it in water for a few minutes. A very rough dissection will then enable you to detect the future butterfly; and you will find that the wings, rolled up into a sort of cord, are lodged between the first and second segment of the caterpillar; that the antennæ and trunk are coiled up in front of the head; and that the legs, however different their form, are actually sheathed in its legs. Malpighi discovered the eggs of the future moth, in the chrysalis of a silkworm only a few days old[99], and Reaumur those of another moth (Hypogymna dispar) even in the caterpillar, and that seven or eight days before its change into the pupa[100]. A caterpillar, then, may be regarded as a locomotive egg, having for its embryo the included butterfly, which after a certain period assimilates to itself the animal substances by which it is surrounded; has its organs gradually developed; and at length breaks through the shell which incloses it.

This explanation strips the subject of every thing miraculous, yet by no means reduces it to a simple or uninteresting operation. Our reason is confounded at the reflection that a larva, at first not thicker than a thread, includes its own triple, or sometimes octuple, teguments; the case of a chrysalis, and a butterfly, all curiously folded in each other; with an apparatus of vessels for breathing and digesting, of nerves for sensation, and of muscles for moving; and that these various forms of existence will undergo their successive evolutions, by aid of a few leaves received into its stomach. And still less able are we to comprehend how this organ should at one time be capable of digesting leaves, at another only honey; how one while a silky fluid should be secreted, at another none; or how organs at one period essential to the existence of the insect, should at another be cast off, and the whole system which supported them vanish.

Nor does this explanation, though it precludes the idea of that resemblance, in every particular, which, at one time, was thought to obtain between the metamorphosis of insects, especially of the Lepidoptera order, and the resurrection of the body, do away that general analogy which cannot fail to strike every one who at all considers the subject. Even Swammerdam, whose observations have proved that the analogy is not so complete as had been imagined, speaking of the metamorphosis of insects, uses these strong words: "This process is formed in so remarkable a manner in butterflies, that we see therein the resurrection painted before our eyes, and exemplified so as to be examined by our hands[101]." To see, indeed, a caterpillar crawling upon the earth, sustained by the most ordinary kinds of food, which, when it has existed a few weeks or months under this humble form, its appointed work being finished, passes into an intermediate state of seeming death, when it is wound up in a kind of shroud and encased in a coffin, and is most commonly buried under the earth, (though sometimes its sepulchre is in the water, and at others in various substances in the air,) and after this creature and others of its tribe have remained their destined time in this death-like state, to behold earth, air, and water, give up their several prisoners: to survey them, when, called by the warmth of the solar beam, they burst from their sepulchres, cast off their cerements, from this state of torpid inactivity, come forth, as a bride out of her chamber,—to survey them, I say, arrayed in their nuptial glory, prepared to enjoy a new and more exalted condition of life, in which all their powers are developed, and they are arrived at the perfection of their nature; when no longer confined to the earth they can traverse the fields of air, their food is the nectar of flowers, and love begins his blissful reign;—who that witnesses this interesting scene can help seeing in it a lively representation of man in his threefold state of existence, and more especially of that happy day, when at the call of the great Sun of Righteousness, all that are in the graves shall come forth, the sea shall give up her dead, and death being swallowed up of life, the nations of the blessed shall live and love to the ages of eternity?

But although the analogy between the different states of insects and those of the body of man is only general, yet it is much more complete with respect to his soul. He first appears in this frail body—a child of the earth, a crawling worm, his soul being in a course of training and preparation for a more perfect and glorious existence. Its course being finished, it casts off the earthy body, and goes into a hidden state of being in Hades, where it rests from its works, and is prepared for its final consummation. The time for this being arrived, it comes forth clothed with a glorious body, not like its former, though germinating from it, for though "it was sown an animal body, it shall be raised a spiritual body," endowed with augmented powers, faculties and privileges commensurate to its new and happy state. And here the parallel holds perfectly between the insect and the man. The butterfly, the representative of the soul, is prepared in the larva for its future state of glory; and if it be not destroyed by the ichneumons and other enemies to which it is exposed, symbolical of the vices that destroy the spiritual life of the soul, it will come to its state of repose in the pupa, which is its Hades; and at length, when it assumes the imago, break forth with new powers and beauty to its final glory and the reign of love. So that in this view of the subject well might the Italian poet exclaim:

Non v' accorgete voi, che noi siam' vermi
Nati a formar l' angelica farfalla[102]?

The Egyptian fable, as it is supposed to be, of Cupid and Psyche, seems built upon this foundation. "Psyche," says an ingenious and learned writer, "means in Greek the human soul; and it means also a butterfly[103], of which apparently strange double sense the undoubted reason is, that a butterfly was a very ancient symbol of the soul—from the prevalence of this symbol, and the consequent coincidence of the names, it happened that the Greek sculptors frequently represented Psyche as subject to Cupid in the shape of a butterfly; and that even when she appears in their works under the human form, we find her decorated with the light and filmy wings of that gay insect[104]."

The following beautiful little poem falls in so exactly with the subject I have been discussing, that I cannot resist the temptation I feel to copy it for you, especially as I am not aware that it has appeared any where but in a newspaper.

THE BUTTERFLY'S BIRTH-DAY.

BY THE AUTHOR OF "THE BUTTERFLY'S BALL."

The shades of night were scarcely fled;
The air was mild, the winds were still;
And slow the slanting sun-beams spread
O'er wood and lawn, o'er heath and hill:

From fleecy clouds of pearly hue
Had dropt a short but balmy shower,
That hung like gems of morning dew
On every tree and every flower:

And from the Blackbird's mellow throat
Was pour'd so loud and long a swell,
As echoed with responsive note
From mountain side and shadowy dell:

When bursting forth to life and light,
The offspring of enraptured May,
The Butterfly, on pinions bright,
Launch'd in full splendour on the day.

Unconscious of a mother's care,
No infant wretchedness she knew;
But as she felt the vernal air,
At once to full perfection grew.

Her slender form, ethereal light,
Her velvet-textured wings infold;
With all the rainbow's colours bright,
And dropt with spots of burnish'd gold.

Trembling with joy awhile she stood,
And felt the sun's enlivening ray;
Drank from the skies the vital flood,
And wonder'd at her plumage gay!

And balanced oft her broider'd wings,
Through fields of air prepared to sail:
Then on her vent'rous journey springs,
And floats along the rising gale.

Go, child of pleasure, range the fields,
Taste all the joys that spring can give,
Partake what bounteous summer yields,
And live whilst yet 'tis thine to live.

Go sip the rose's fragrant dew,
The lily's honeyed cup explore,
From flower to flower the search renew,
And rifle all the woodbine's store:

And let me trace thy vagrant flight,
Thy moments too of short repose,
And mark thee then with fresh delight
Thy golden pinions ope and close.

But hark! whilst thus I musing stand,
Pours on the gale an airy note,
And breathing from a viewless band,
Soft silvery tones around me float!

—They cease—but still a voice I hear,
A whisper'd voice of hope and joy,
"Thy hour of rest approaches near,
"Prepare thee, mortal!—thou must die!

"Yet start not!—on thy closing eyes
"Another day shall still unfold,
"A sun of milder radiance rise,
"A happier age of joys untold.

"Shall the poor worm that shocks thy sight,
"The humblest form in nature's train,
"Thus rise in new-born lustre bright,
"And yet the emblem teach in vain?

"Ah! where were once her golden eyes,
"Her glittering wings of purple pride?
"Conceal'd beneath a rude disguise,
"A shapeless mass to earth allied.

"Like thee the hapless reptile lived,
"Like thee he toil'd, like thee he spun,
"Like thine his closing hour arrived,
"His labour ceased, his web was done.

"And shalt thou, number'd with the dead,
"No happier state of being know?
"And shall no future morrow shed
"On thee a beam of brighter glow?

"Is this the bound of power divine,
"To animate an insect frame?
"Or shall not He who moulded thine
"Wake at his will the vital flame?

"Go, mortal! in thy reptile state,
"Enough to know to thee is given;
"Go, and the joyful truth relate;
"Frail child of earth! high heir of heaven!"

A question here naturally presents itself—Why are insects subject to these changes? For what end is it that, instead of preserving like other animals[105] the same general form from infancy to old age, they appear at one period under a shape so different from that which they finally assume; and why should they pass through an intermediate state of torpidity so extraordinary? I can only answer that such is the will of the Creator, who doubtless had the wisest ends in view, although we are incompetent satisfactorily to discover them. Yet one reason for this conformation may be hazarded. A very important part assigned to insects in the economy of nature, as I shall hereafter show, is that of speedily removing superabundant and decaying animal and vegetable matter. For such agents an insatiable voracity is an indispensable qualification, and not less so unusual powers of multiplication. But these faculties are in a great degree incompatible. An insect occupied in the work of reproduction could not continue its voracious feeding. Its life, therefore, after leaving the egg, is divided into three stages. In the first, as larva, it is in a state of sterility; its sole object is the satisfying its insatiable hunger; and, for digesting the masses of food which it consumes, its intestines are almost all stomach. This is usually by much the longest period of its existence. Having now laid up a store of materials for the development of the future perfect insect, it becomes a pupa; and during this inactive period the important process slowly proceeds, uninterrupted by the calls of appetite. At length the perfect insect is disclosed. It now often requires no food at all; and scarcely ever more than a very small quantity; for the reception of which its stomach has been contracted, in some instances, to a tenth of its former bulk. Its almost sole object is now the multiplication of its kind, from which it is diverted by no other propensity; and this important duty being performed, the end of its existence has been answered, and it expires.

It must be confessed that some objections might be thrown out against this hypothesis, yet I think none that would not admit of a plausible answer. To these it is foreign to my purpose now to attend, and I shall conclude this letter by pointing out to you the variety of new relations which this arrangement introduces into nature. One individual unites in itself, in fact, three species, whose modes of existence are often as different as those of the most distantly related animals of other tribes. The same insect often lives successively in three or four worlds. It is an inhabitant of the water during one period; of the earth during another; and of the air during a third; and fitted for its various abodes by new organs and instruments, and a new form in each. Think (to use an illustration of Bonnet) but of the cocoon of the silkworm! How many hands, how many machines does not this little ball put into motion! Of what riches should we not have been deprived, if the moth of the silkworm had been born a moth, without having been previously a caterpillar! The domestic economy of a large portion of mankind would have been formed on a plan altogether different from that which now prevails.

I am, &c.

[LETTER IV.]

INJURIES CAUSED BY INSECTS.

DIRECT INJURIES.

In the letter which I devoted to the defence of Entomology, I gave you reason to expect, more effectually to obviate the objection drawn from the supposed insignificance of insects, that I should enter largely into the question of their importance to us both as instruments of good and evil. This I shall now attempt; and, as I wish to leave upon your mind a pleasant impression with respect to my favourites, I shall begin with the last of these subjects—the injury which they do to us.

The Almighty ordains various instruments for the punishment of offending nations: sometimes he breaks them to pieces with the iron rod of war; at others the elements are let loose against them; earthquakes and floods of fire, at his word, bring sudden destruction upon them; seasons unfriendly to vegetation threaten them with famine; the blight and mildew realize these threats; and often, the more to manifest and glorify his power, he employs means, at first sight, apparently the most insignificant and inadequate to effect their ruin; the numerous tribes of insects are his armies[106], marshalled by him, and by his irresistible command impelled to the work of destruction: where he directs them they lay waste the earth, and famine and the pestilence often follow in their train.

The generality of mankind overlook or disregard these powerful, because minute, dispensers of punishment; seldom considering in how many ways their welfare is affected by them: but the fact is certain, that should it please God to give them a general commission against us, and should he excite them to attack, at the same time, our bodies, our clothing, our houses, our cattle, and the produce of our fields and gardens, we should soon be reduced, in every possible respect, to a state of extreme wretchedness; the prey of the most filthy and disgusting diseases, divested of a covering, unsheltered, except by caves and dungeons, from the inclemency of the seasons, exposed to all the extremities of want and famine; and in the end, as Sir Joseph Banks, speaking on this subject, has well observed[107], driven with all the larger animals from the face of the earth. You may smile, perhaps, and think this a high-coloured picture, but you will recollect—I am not stating the mischiefs that insects commonly do, but what they would do according to all probability, if certain counter-checks restraining them within due limits had not been put in action; and which they actually do, as you will see, in particular cases, when those counter-checks are diminished or removed.

Insects may be said, without hyperbole, to have established a kind of universal empire over the earth and its inhabitants. This is principally conspicuous in the injuries which they occasion, for nothing in nature that possesses or has possessed animal or vegetable life, is safe from their inroads. Neither the cunning of the fox, nor the swiftness of the horse or deer, nor the strength of the buffalo, nor the ferocity of the lion or tiger, nor the armour of the rhinoceros, nor the giant bulk or sagacity of the elephant, nor even the authority of imperial man, who boasts himself to be the lord of all, can secure them from becoming a prey to these despised beings. The air affords no protection to the birds, nor the water to the fish; insects pursue them all to their most secret conclaves and strongest citadels, and compel them to submit to their sway. Flora's empire is still more exposed to their cruel domination and ravages; and there is scarcely one of her innumerable subjects, from the oak, the glory of the forest, to the most minute lichen that grows upon its trunk, that is not destined to be the food of these next to nonentities in our estimation. And when life departs from man, the inferior animals, or vegetables, they become universally, sooner or later, the inheritance of insects.

I shall principally bespeak your attention to the injuries in question as they affect ourselves. These may be divided into direct and indirect. By direct injuries I mean every species of attack upon our own persons, and by indirect, such as are made upon our property. To the former of these I shall confine myself in the present letter.

Insects, as to their direct attacks upon us, may be arranged in three principal classes. Those, namely, which seek to make us their food; those whose object is to prevent or revenge an injury which they either fear, or have received from us; and those which indeed offer us no violence, but yet incommode us extremely in other ways.

I hope I shall not too much offend your delicacy if I begin the first class of our insect assailants with a very disgusting genus, which Providence seems to have created to punish inattention to personal cleanliness. But though this pest of man must not be wholly passed over, yet, since it is unfortunately too well known, it will not be at all necessary for me to enlarge upon its history. I shall only mention one fact which shows the astonishingly rapid increase of these animals, where they have once gotten possession. It is a vulgar notion, that a louse in twenty-four hours may see two generations; but this is rather overshooting the mark. Leeuwenhoek, whose love for science overcame the nausea that such creatures are apt to excite, proves that their nits or eggs are not hatched till the eighth day after they are laid, and that they do not themselves commence laying before they are a month old. He ascertained, however, that a single female louse may, in eight weeks, witness the birth of five thousand descendants[108]. You remember how wolves were extirpated from this country, but perhaps never suspected any monarch of imposing a tribute of lice upon his subjects. Yet we are gravely told that in Mexico and Peru such a poll-tax was exacted, and that bags full of these treasures were found in the palace of Montezuma[109]!!! Were our own taxes paid in such coin, what little grumbling would there be!

Two other species of this genus, besides the common louse, are, in this country, parasites upon the human body——But already I seem to hear you exclaim, "Why dwell so long on creatures so odious and nauseating, whose injuries are confined to the profanum vulgus? Leave them therefore to the canaille—they are nothing to us." Not so fast, my friend—recollect what historians and other writers have recorded concerning the Phthiriasis or pedicular disease, and you must own that, for the quelling of human pride, and to pull down the high conceits of mortal man, this most loathsome of all maladies, or one equally disgusting, has been the inheritance of the rich, the wise, the noble, and the mighty; and in the list of those that have fallen victims to it, you will find poets, philosophers, prelates, princes, kings, and emperors. It seems more particularly to have been a judgement of God upon oppression and tyranny, whether civil or religious. Thus the inhuman Pheretima mentioned by Herodotus, Antiochus Epiphanes, the Dictator Sylla, the two Herods, the Emperor Maximin, and, not to mention more, the great persecutor of the Protestants, Philip the Second, were carried off by it.

I say by this malady, or one equally disgusting, because it is not by any means certain, though some learned men have so supposed, that all these instances, and others of a similar nature, standing also upon record, are to be referred to the same specific cause; since there is very sufficient reason for thinking that at least three different descriptions of insects are concerned in the various cases that have been handed down to us under the common name of Phthiriasis. As the subject of maladies connected with insects, or produced by them, is both curious and interesting, although no writer, that I am aware of, has given it full consideration, and at the same time falls in with my general design, I hope you will not regard me as guilty of presumption, and of intruding into the province of medical men, if I enter rather largely into it, and state to you the reasons that have induced me to embrace the above hypothesis, leaving you full liberty to reject it if you do not find it consonant to reason and fact. The three kinds of insects to which I allude, as concerned in cases that have been deemed Phthiriasis, are lice (Pediculi, L.) mites (Acari, L.), and Larvæ in general.

As far as the habits of the genus Pediculus, whether inhabiting man or the inferior animals, are at present known, it does not appear, from any well ascertained fact, that the species belonging to it are ever subcutaneous. For this observation, as far as it relates to man, I can produce the highest medical authority. "The louse feeds on the surface of the skin," says the learned Dr. Mead in his Medica Sacra; and Dr. Willan, in his palmary work on Cutaneous Diseases, remarks with respect to the body-louse, "that the nits, or eggs, are deposited on the small hairs of the skin," and that "the animals are found on the skin, or on the linen, and not under the cuticle, as some authors have represented." And he further observes, that "many marvellous stories are related by Forestus, Schenkius and others respecting lice bred under the skin, and discharged in swarms from abscesses, strumous ulcers, and vesications. The mode in which Pediculi are generated being now so well ascertained, no credit can be given to these accounts." Thus far this great man, who however supposes (in which opinion Dr. Bateman concurs with him) that the authors to whom he alludes had mistaken for lice some other species of insects, which are not unfrequently found in putrefactive sores.

If these observations be allowed their due weight, it will follow, that a disease produced by animals residing under the cuticle cannot be a true Phthiriasis, and therefore the death of the poet Alcman, and of Pherecydes Syrius the philosopher, mentioned by Aristotle, must have been occasioned by some other kind of insect. For, speaking of the lice to which he attributes these catastrophes, he says that "they are produced in the flesh in small pustule-like tumours, which have no pus, and from which when punctured, they issue[110]." For the same reason, the disorder which Dr. Heberden has described in his Commentaries, from the communications of Sir E. Wilmot, under the name of Morbus pedicularis, must also be a different disease, since, with Aristotle, he likewise represents the insects as inhabiting tumours, from which they may be extracted when opened by a needle. He says, indeed, that in every respect they resemble the common lice, except in being whiter; but medical men, who were not at the same time entomologists, might easily mistake an Acarus for a Pediculus[111].

Dr. Willan, in one case of Prurigo senilis, observed a number of small insects on the patient's skin and linen. They were quick in their motion, and so minute that it required some attention to discover them. He took them at first for small Pediculi; but under a lens they appeared to him rather to be a nondescript species of Pulex[112]; yet the figure he gives has not the slightest likeness to the latter genus, while it bears a striking resemblance to the former. It is not clear whether his draughtsman meant to represent the insect with six or with eight legs: if it had only six, it was probably a Pediculus; but if it had eight, it would form a new genus between the Acarina and the hexapod Aptera. Dr. Bateman, in reply to some queries put to him, at my request, by our common and lamented friend Dr. Reeve, relates that he understood from Dr. Willan, in conversation, that the insect in question jumped in its motion. This circumstance he regards as conclusive against its being a Pediculus; but such a consequence does not necessarily follow, since it not seldom happens that insects of the same tribe or genus either have or have not this faculty; for instance, compare Scirtes with Cyphon, small beetles, and Acarus Scabiei with other Acari[113].

Dr. Willan has quoted with approbation two cases from Amatus Lusitanus, which he seems to think correctly described as Phthiriasis. In one of them, however, which terminated fatally, the circumstances seem rather hyperbolically stated—I mean, where it is said that two black servants had no other employment than carrying baskets full of these insects to the sea!! Perhaps you will think I draw largely upon your credulity if I call upon you to believe this; I shall therefore leave you to act as you please.—Thus much for pure Phthiriasis, which term ought to be confined to maladies produced by lice. I shall only further observe, that as many species as exist of these, which are the causes of disease, so many kinds of Phthiriasis will there be.

Acari, or mites, are the next insect sources of disease in the human species, and that not of one, but probably of many kinds both local and general. They are distinguished from Pediculi not only by their form, but also often by their situation, since they frequently establish themselves under the cuticle. With respect to local disorders, Dr. Adams conjectures that Acari may be the cause of certain cases of Ophthalmia. Sir J. Banks, in a letter to that gentleman, relates that some seamen belonging to the Endeavour brig, being tormented with a severe itching round the extremities of the eyelids, one of them was cured by an Otaheitan woman, who with two small splinters of bamboo extracted from between the cilia abundance of very minute lice, which were scarcely visible without a lens, though their motion, when laid on the thumb, was distinctly perceived. These insects were probably synonymous with the Ciron des paupières of Sauvages[114].—Le Jeune, a French physician quoted in Mouffet, describes a case, in which what seems a different species, since he calls them rather large, infested the white of the eye, exciting an intolerable itching[115].—Dr. Mead, from the German Ephemerides, gives an account of a woman suckling her child, from whose breast proceeded very minute vermicles[116]. These were probably mites, and perhaps that species, which, from its feeding upon milk, Linné denominates Acarus Lactis. The great author last mentioned describes an insect, a native of America, under the name of Pediculus Ricinoides, which, upon the authority of Rolander, he informs us, gets into the feet of people as they walk, sucks their blood, oviposits[117] in them, and so occasions very dangerous ulcers. It would be an Acarus, he observes, but it has only six legs. Now Hermann affirms, that some species of Trombidium (a genus separated by Fabricius from Acarus) have in no state more than six legs[118]. Others of the tribe of Acarina, and the insect in question amongst the rest, may be similarly circumstanced; or those that Rolander examined might have been larvæ, which in this tribe are usually hexapods.

Linné appears to have been of opinion that many contagious diseases are caused by mites[119]. How far he was justified in this opinion I shall not here inquire; facts alone can decide the question, and observations made by men acquainted with Entomology as well as the science of diseases. Considerable deference and attention, however, are certainly due to the sentiments of so great a naturalist, in whom these necessary qualifications were united in no common degree. With respect to the dysentery and the itch, he affirms that this had been manifested to his eyes. You will wish probably to know the arguments that may be adduced in confirmation of this opinion; I will therefore endeavour to satisfy you as well as I am able. The following history given by Linné seems to prove the dysentery connected with these animals.

Rolander, a student in Entomology, while he resided in the house of the illustrious Swede, was attacked by the disease in question, which quickly gave way to the usual remedies. Eight days after, it returned again, and was as before soon removed. A third time, at the end of the same period, he was seized with it. All the while he had been living like the rest of the family, who had nevertheless escaped. This, of course, occasioned no little inquiry into the cause of what had happened. Linné, aware that Bartholinus had attributed the dysentery to insects, which he professed to have seen, recommended it to his pupil to examine his feces. Rolander, following this advice, discovered in them innumerable animalcules, which upon a close examination proved to be mites. It was next a question how he alone came to be singled out by them; and thus he accounts for it. It was his habit not to drink at his meals; but in the night, growing thirsty, he often sipped some liquid out of a vessel made of juniper wood. Inspecting this very narrowly, he observed, in the chinks between the ribs, a white line, which, when viewed under a lens, he found to consist of innumerable mites, precisely the same with those that he had voided. Various experiments were tried with them, and a preparation of rhubarb was found to destroy them most effectually. He afterwards discovered them in vessels containing acids, and often under the bung of casks[120]. In the instance here recorded, the dysentery, or diarrhœa, was evidently produced by a species of mite, which Linné hence called Acarus Dysenteriæ; but it would be going too far, I apprehend, to assert that they are invariably the cause of that disease.

That Scabies, or the itch, is occasioned by a mite, is not a doctrine peculiar to the moderns. Mouffet mentions Abinzoar, called also Avenzoar, a celebrated Hispano-Arabian physician of Seville, who flourished in the twelfth century, as the most ancient author that notices it. He calls these mites little lice that creep under the skin of the hands, legs, and feet, exciting pustules full of fluid[121]. Joubert, quoted by the same author, describes them under the name of Sirones, as always being concealed beneath the epidermis, under which they creep like moles, gnawing it, and causing a most troublesome itching. It appears that Mouffet, or whoever was the author of that part of the Theatrum Insectorum, was himself also well acquainted with these animals, since he remarks that their habitation is not in the pustule but near it: a remark afterwards confirmed by Linné[122], and more recently by Dr. Adams[123]. In common with the former of these authors, Mouffet further notices the effect of warmth upon them in exciting motion[124]. Our intelligent countryman also observes that they cannot be Pediculi, since they live under the cuticle, which lice never do[125]. In the epistle dedicatory, the editor speaks also of them as living in burrows which they have excavated in the skin near a lake of water; from which if they be extracted with a needle and put upon the nail, they show in the sun their red head and the feet with which they walk[126]. And to close my veteran authorities, Junius thus explains the word Acarus, as I find him quoted in Gouldman's useful dictionary, "A small worm, which eats under the skin, and makes burrows in itching hands[127]."

In more modern times, microscopical figures have been added to descriptions of the insect. Bonomo first furnished this valuable species of elucidation. His figures, however, which are copied by Baker in his work on the microscope, are far from accurate[128]. Those of De Geer and Dr. Adams are much more satisfactory, and mutually confirm each other[129]. From them it is evident that the same insect inhabits the scabies of Sweden and Madeira. Dr. Bateman, in the letter before alluded to, informs his correspondent, that he had seen that from Madeira, and gives it as his opinion, that there cannot be a doubt of the existence of an Acarus Scabiei; an opinion which he repeats in his late work on Cutaneous Diseases; and which, according to Hermann[130], has been also rendered unquestionable by Wichmann in his Etiologie de la Gale (Hanovre 1786), a work I have not had an opportunity of consulting. From all this we may regard the point as so far settled, that an animal of this kind exists at least as an occasional concomitant of scabies.

This fact being ascertained, a more complex inquiry remains, which branches out into two distinct questions. Is scabies always produced by these insects? Or, if this be not the case, Is the animate scabies a distinct disease from the inanimate?

It is very remarkable that Linné, a physician as well as a naturalist; and De Geer, one of the most accurate observers that ever existed; should both assign the insect in question as the undoubted cause of the common scabies of their country; the one applying to the disease he was speaking of the epithet of communissima, and observing the fact to be notorious, (cuique liquet,) and the other designating it by its well known French name "La Gale[131]." And is it not equally remarkable that such men as John Hunter, Dr. Heberden, Dr. Bateman, Dr. Adams, and Mr. Baker, should never, in this country, have been able to meet with it? Did it indeed exist in our common scabies, it seems impossible that it could have escaped the observation of the two last of these gentlemen; Dr. Adams being so well qualified to detect it from his observations in Madeira, and Mr. Baker from his expertness in microscopical researches. Dr. Bateman, in the letter above quoted, says, "I have hunted it with a good magnifier, in many cases of itch, both in and near the pustules, and in the red streaks or furrows, but always without success." In his work on Cutaneous Diseases he tells us, however, that he has seen it, in one instance, when it had been taken from the diseased surface by another practitioner. And though Dr. Willan in his book speaks of the Acarus as the concomitant of this disease, yet his learned friend just mentioned observes, that he admitted that it was not to be found in ordinary cases, and indeed never seemed to have made up his mind upon the subject. When I was at Norwich in 1812, Dr. Reeve very kindly accompanied me to the House of Industry there, to examine a patient whose body was very full of the pustules of this disorder; but though we used a good magnifier, we could discover nothing like an insect. I must observe, however, that our examination was made in December, in severe weather, when the cold might, perhaps, render the animal torpid, and less easy to be discovered.

From the above facts it seems fair to infer that this animal is not invariably the cause of scabies, but that there are cases with which it has no connexion. Now, from this inference, would not another also follow, that the disease produced by the insect is specifically distinct from that in which it cannot be found? Sauvages and Dr. Adams are both of this opinion[132], the former assigning to it the trivial name of vermicularis; and the latter proving, by very satisfactory arguments, that it is different from the other. If they were both animate diseases, but derived from two distinct species of animals, (for it seems not impossible that even our common itch may be caused by a mite more minute than the other, and so more difficult to find,) they would properly be considered as distinct species; much more, therefore, if one be animate and the other inanimate. Nay this, I should think, would lead to a doubt whether even their genus were the same. I shall dismiss this part of my subject with the mention of a discovery of Dr. Adams, which seems to have escaped both Linné and De Geer—that the Acarus Scabiei is endowed with the faculty of leaping; (in this respect resembling the insect found by Willan in Prurigo senilis mentioned above;) for which purpose its four posterior thighs are incrassated[133].

But besides these Acarine diseases, there seems to be one (unless with Linné we regard the plague as of this class[134]) more fearful and fatal than them all. You will, perhaps, conjecture I am speaking of that described by Aristotle and Sir E. Wilmot as the Phthiriasis, and your conjecture will be right. But some think, and those men of merited celebrity, that mites have nothing to do in these and similar cases, for that maggots were the parasites mistaken for lice. This, from the passage above quoted, appears to have been Dr. Willan's opinion, to which, in the letter so often referred to, Dr. Bateman subscribes; adding as a reason for excluding mites from being concerned, that "they are too minute, and never have been seen in such numbers as to be mistaken for lice." But both vary in size, some of the former being larger than some of the latter. And allowing them to be ever so minute, yet when they issue in swarms, as mites from a cheese, they would be very visible, were it only from their motion. Besides, as they are furnished with legs, their motions resemble those of lice infinitely more than do the contortions of maggots. So that a mite would be deemed a louse much sooner by an unentomological observer than would a maggot. Whether mites have ever been seen in such numbers as to be mistaken for lice, is the point in question; and therefore, by itself, cannot be admitted for a valid argument. Though Acarus Scabiei does not appear to swarm in ordinary cases, yet this is certainly no reason why other species may not do so. Where it has once made a settlement, how incredibly, and in how short a space of time, does the Siro or cheese-mite multiply! Acarus Destructor and many other species are equally rapid in their increase.—Millions of lice are said by Lafontaine, whom Hermann calls a very exact describer, to show themselves in Plica polonica, on the third day of the disease[135]; but whether the last-mentioned author be correct in thinking it more probable that they are mites[136], I have not the means of judging.

I shall now produce two instances where mites were evidently concerned. Dr. Mead, from the German Ephemerides, relates the miserable case of a French nobleman, from whose eyes, nostrils, mouth, and urinary passage animalcules of a red colour, and excessively minute, broke forth day and night, attended by the most horrible and excruciating pains, and at length occasioned his death. The account further says, that they were produced from his corrupted blood. This was probably a fancy originating in their red colour: but the whole history, whether we consider the size and colour of the animals, or the places from which they issue, is inapplicable to larvæ or maggots, and agrees very well with mites, some of which, particularly Leptus autumnalis, are of a bright red colour. The other case, and a very similar one, is that recorded by Mouffet of Lady Penruddock; concerning whom he expressly tells us, that Acari swarmed in every part of her body—her head, eyes, nose, lips, gums, the soles of her feet, &c., tormenting her day and night, till, in spite of every remedy, all the flesh of her body being consumed, she was at length relieved by death from this terrible state of suffering. Mouffet attributes her disease to the Acarus Scabiei; but from the symptoms and fatal result it seems to have been a different and much more terrific animal. He supposes, in this instance, the insect to have been generated by drinking goat's milk too copiously. This, if correct, would lead to a conjecture that it might have been the A. Lactis, L.

These cases I hope will satisfy you that mites, as well as lice, are the cause of diseases in the human frame. This, indeed, as has been before observed, is allowed on all hands with respect to that of the itch; and it is, certainly, not more improbable that man should be exposed to the attack of several species of this genus, than that three or four kinds of Pediculus should infest him. If you are convinced by what I have written, you will concur with me in thinking that the one are as much entitled to give their name to the disease which they produce as the other; and the term Acariasis, by which, with due deference to medical men, I propose to distinguish generically all acarine diseases, will not be refused its place amongst your Genera Morborum.

I shall now proceed to the remaining class of diseases mistaken for Phthiriasis; those, namely, which are produced by larvæ. There are two terms employed by ancient authors, Eulæ (Ευλαι) and Scolex (Σκωληξ), which seem properly to denote larvæ; but there is often such a want of precision in the language of writers unacquainted with Natural History, that it is very difficult to make out what objects they mean; and expressions which, strictly taken, should be understood of larvæ, may probably sometimes have been used to denote the cause of either the pedicular or acarine disease. Eulæ, which term, though given by Hesychius as synonymous with Scolex, is by Plutarch used as of different import[137], seems properly to mean those larvæ which are generated in dead carcases, at least so Homer has more than once applied it[138]: it is therefore a word of a much more restricted sense than Scolex, which probably belongs to the larvæ of every order of insects; for so Aristotle employs it, when he says that all insects produce a Scolex, or are larviparous[139]. Yet when Homer compares Harpalion stretched dead upon the ground to a Scolex[140], it should seem as if he used the word for an earth-worm, which Aristotle commonly calls by a figurative periphrasis, "Entrails of the earth[141]." In the Holy Scriptures this word is used to signify larvæ which prey upon and are the torment of living bodies[142]. It may on this account, perhaps, be regarded as generally meaning such larvæ, to whatever order or genus they belong.

Dr. Mead, therefore, is most probably right when he considers the disease stated by the ancients to be caused by Eulæ or Scoleches, commonly translated worms, as distinct from Phthiriasis; and if so, the inhuman Pheretima, who swarmed with Eulæ, and Herod Agrippa, who was eaten of Scoleches[143], were probably neither of them destroyed either by Pediculi or Acari, but by larvæ or maggots. And when Galen prescribed a remedy for ulcers inhabited by Scoleches, observing that animals similar to those generated by putrid substances are often found in abscesses, he probably meant the same thing. The proper appellation of this genus of diseases would be Scolechiasis.

This dissertation may perhaps appear to you rather prolix and tedious: yet to settle the meaning of terms is of the first importance. To inquire what ancient writers intended by the words which they employ, and whether such as have been usually regarded as synonymous are really so, may often furnish us with a clue to some useful or interesting truth; and not seldom enable us to rescue their reputation from much of the censure which has been inconsiderately cast upon it. Because they did not know every thing, or so much as we do, we are too apt to think that they knew nothing. That they fell into very considerable errors, especially in subjects connected with Natural History, cannot be denied; but then it ought to be considered that they possessed scarcely any of those advantages by which we are enabled to penetrate into nature's secrets. The want of the microscope alone was an effectual bar to their progress in this branch of science. Yet, in some instances, when they took a general view of a subject, they appear to have had very correct ideas. This observation particularly applies to the philosopher of Stagyra, whose mighty mind and lyncean eye, in spite of those mists of prejudice and fable that enveloped the age in which he lived, enabled him in part to pierce through the gloom, and comprehend and behold the fair outline that gives symmetry, grace and beauty to the whole of nature's form, though he mistook, or was not able to trace out, her less prominent features and minor lineaments.

It is now time to return from this long digression, which however is closely connected with the subject of this letter, to the point from which I deviated. Taking my leave of the disgusting animals which gave rise to it, I proceed to call your attention to another of our pygmy tormentors, (Pulex irritans,) which, in the opinion of some, seems to have been regarded as an agreeable rather than a repulsive object. "Dear miss," said a lively old lady to a friend of mine, (who had the misfortune to be confined to her bed by a broken limb, and was complaining that the fleas tormented her,) "don't you like fleas? Well, I think they are the prettiest little merry things in the world.—I never saw a dull flea in all my life." The celebrated Willughby kept a favourite flea, which used at stated times to be admitted to suck the palm of his hand; and enjoyed this privilege for three months, when the cold killed it. And Dr. Townson, from the encomium which he bestows upon these vigilant little vaulters, as supplying the place of an alarum and driving us from the bed of sloth, should seem to have regarded them with feelings much more complacent than those of Dr. Clarke and his friends, when their hopes of passing "one night free from the attacks of vermin" were changed into despair by the information of the laughing Sheik, that "the king of the fleas held his court at Tiberias:" or than those of MM. Lewis and Clarke, who found them more tormenting than all the other plagues of the Missouri country, where they sometimes compel even the natives to shift their quarters. If you unhappily view them in this unfavourable light, and have found ordinary methods unavailing for ridding yourself of these unbidden guests; I can furnish you with a probatum est recipe, which the first-mentioned traveller tells us the Hungarian shepherds (who seem to have been stupidly insensible to their value as alarums) find completely effectual to put to flight these insects and their neighbours the lice. This is not, as you may be tempted to think, by a remarkable attention to cleanliness.—Quite the reverse.—They grease their linen with hog's lard, and thus render themselves disgusting even to fleas! If this does not satisfy, I have another recipe in store for you. You may shoot at them with a cannon, as report says did Christina queen of Sweden, whose piece of artillery, of Lilliputian calibre, which was employed in this warfare, is still exhibited in the arsenal of Stockholm[144]. But, seriously, if you wish for an effectual remedy, that prescribed by old Tusser, in the following lines, will answer your purpose:

"While wormwood hath seed, get a handfull or twaine,
To save against March, to make flea to refraine:
Where chamber is sweeped, and wormwood is strown,
No flea for his life dare abide to be known."

To this genus belongs an insect, abundant in the West Indies and South America, the attacks of which are infinitely more serious than those of the common flea. You will readily conjecture that I am speaking of the celebrated Chigoe or Jiggers, called also Nigua, Tungua, and Pique[145], (Pulex penetrans,) one of the direst personal pests with which the sins of man have been visited. All disputes concerning the genus of this insect would have been settled long before Swartz's time, (who first gave a satisfactory description and figure of it, proving it to be a Pulex, as has been observed above[146],) had success attended the patriotic attempt of the Capuchin friar recorded by Walton in his History of St. Domingo, who brought away with him from that island a colony of these animals, which he permitted to establish themselves in one of his feet; but unfortunately for himself, and for science, the foot intrusted with the precious deposit mortified, was obliged to be amputated, and with all its inhabitants committed to the waves. According to Ulloa, and his opinion is confirmed by Jussieu, there are two South American species of this mischievous insect. It is described as generally attacking the feet and legs[147], getting, without being felt, between the skin and the flesh, usually under the nails of the toes, where it nidificates and lays its eggs; and if timely attention be not paid to it, which, as it occasions no other uneasiness than itching, (the sensation at first, I am assured, is rather pleasing than otherwise,) is sometimes neglected, it multiplies to such a degree, as to be attended by the most fatal consequences, often, as in the above instance, rendering amputation necessary, and sometimes causing death[148]. The female slaves in the West Indies are frequently employed to extract these pests, which they do with uncommon dexterity. Yarico, so celebrated in prose and verse, performed this kind office for honest Ligon, who says, in his History of Barbadoes, "I have had ten (Chegoes) taken out of my feet in a morning, by the most unfortunate Yarico, an Indian woman[149]." Humboldt observes, "that the whites born in the torrid zone walk barefoot with impunity in the same apartment where a European recently landed is exposed to the attack of this animal. The Nigua therefore distinguishes what the most delicate chemical analysis could not distinguish, the cellular membrane and blood of a European from those of a creole white[150]."

You have already, perhaps, been satiated with the account before given of our enemies of the Acarus tribe: there are a few, however, which I could not with propriety introduce there, as they do not take up their abode and breed in us, which nevertheless annoy us considerably. One of these is a hexapod so minute, that, were it not for the uncommon brilliancy of its colour, which is the most vivid crimson that can be conceived, it would be quite invisible. It is known by the name of the harvest-bug, (Leptus autumnalis,) and is so called, I imagine, from its attacking the legs of the labourers employed in the harvest, in the flesh of which it buries itself at the root of the hairs, producing intolerable itching, attended by inflammation and considerable tumours, and sometimes even occasioning fevers[151].—A similar insect is found in Brazil, abounding in the rainy season, particularly during the gleams of sunshine, or fine days that intervene; as small as a point, and moving very fast. These animals get upon the linen and cover it in a moment; afterwards they insinuate themselves into the skin and occasion a most intolerable itching. They are with difficulty extracted, and leave behind them large livid tumours, which subside in a day or two. An insect very tormenting to the wood-cutters and the settlers on the Mosquito shore and the bay of Honduras, and called by them the doctor, is thought to be synonymous with this[152].—More serious consequences have been known to follow the bite of another mite related to the above, if not the same species, common in Martinique, and called there the Bête rouge. When our soldiers in camp were attacked by this animal, dangerous ulcers succeeded the symptoms just mentioned, which, in several cases, became so bad, that the limb affected was obliged to be taken off[153].

I was once collecting insects in Norwood, near London, when my hands were covered by a number of small hungry ticks, which were so greedy after blood, that they penetrated deep into my flesh, giving me no little pain; and it was not without difficulty that I extracted them. I suspect that this was the dog-tick (Ixodes Ricinus) which is often found on plants; but I am not certain, as I neglected to examine it, my attention at that time being almost wholly given to Coleoptera. Lyonnet seems to have been attacked, in one of his entomological excursions, by the same or a similar insect, which he broke, so firmly had it fixed itself, in endeavouring to extract it; and he was obliged to lay open the place lest an abscess should be formed[154]. But the worst of all the tick tribe is the American (Ixodes americanus) described by Professor Kalm. This insect, which is related to the preceding, is found in the woods of North America, and is equally an enemy to man and beast. They are there so infinitely numerous, that if you sit down upon the ground, or upon the trunk of a tree, or walk with naked feet or legs, they will cover you, and, plunging their serrated rostrum into the bare places of the body, begin to suck your blood, going deeper and deeper till they are half buried in the flesh. Though at first they occasion no uneasiness, when they have thus made good their settlement, they produce an intolerable itching, followed by acute pain and large tumours. It is now extremely difficult to extract them, the animal rather suffering itself to be pulled to pieces than let go its hold; so that the rostrum and head being often left in the wound, produce an inflammation and suppuration which render it deep and dangerous. These ticks are at first very small, sometimes scarcely visible, but by suction will swell themselves out till they are as big as the end of one's finger, when they often fall to the ground of themselves[155]. The serrated haustellum of the ticks, which, like the barbed sting of a bee, cannot be extracted unless the animal cooperates, is well worth your inspection; and the species which infests our dogs is so common that you will have no difficulty in procuring one for examination.

I have now introduced you to the principal insects of the Aptera order of Linné, which, in spite of all his care and all his power, assail the lord of the creation, and make him their food. You will here, however, perhaps accuse me of omitting one very prominent annoyer of our comfort and repose, which you think belongs to this tribe—the bed-bug (Cimex lectularius). When you are a more practised entomologist, you will see clearly that this, though it has no wings, appertains to another order: nevertheless it may be introduced here without impropriety. Though now too common and well known, in this country it was formerly a rare insect. Had it not, two noble ladies, mentioned by Mouffet, would scarcely have been thrown into such an alarm by the appearance of bug-bites upon them; which, until their fears were dispelled by their physician, who happened also to be a naturalist, they considered as nothing less than symptoms of the plague. Being shown the living cause of their fright, their fears gave place to mirth and laughter[156]. Commerce, with many good things, has also introduced amongst us many great evils, of which noxious insects form no small part; and one of her worst presents were doubtless the disgusting animals now before us. They seem, indeed, as the above fact proves, to have been productive of greater alarm at first than mischief, at least if we may judge from the change of name which took place upon their becoming common. Their original English name was Chinche or Wall-louse[157]; and the term Bug, which is a Celtic word, signifying a ghost or goblin, was applied to them after Ray's time, most probably because they were considered as "terrors by night[158]." But however horrible bugs may have been in the estimation of some, or nauseating in that of others, many of the good people of London seem to regard them with the greatest apathy, and take very little pains to get rid of them; not generally, however, it is to be hoped, to such an extent as the predecessor of a correspondent in Nicholson's Journal, who found his house so dreadfully infested by them, that it resembled the Banian hospital at Surat[159], all his endeavours to destroy them being at first in vain. And no wonder; for, as he learned from a neighbour, his predecessor would never suffer them to be disturbed or his bedsteads to be removed, till, in the end, they swarmed to an incredible degree, crawling up even the walls of his drawing-room; and after his death millions were found in his bed and chamber furniture[160].

The winged insects of the order to which the bed-bug belongs, often inflict very painful wounds.—I was once attacked by a small species, near Cimex Nemorum, L. (Hylophila, K.), which put me nearly to as much torture as the sting of a wasp. The water boatman (Notonecta glauca), an insect related to the Cimicidæ, which always swims upon its back, made me suffer still more severely, as if I had been burned, by the insertion of its rostrum; but the wound was not followed by any inflammation; and long before me Willughby had made the same discovery and observation[161]. St. Pierre, in his Voyage to Mauritius, mentions a species of bug found in that island, the bite of which is more venomous than the sting of a scorpion, and is succeeded by a tumour as big as the egg of a pigeon, which continues for four or five days. You are well acquainted with the history and properties of the Raia Torpedo and Gymnotus electricus; but, I dare aver, have no idea that any insect possesses their extraordinary powers.—Yet I can assure you, upon good authority, that Reduvius serratus, commonly known in the West Indies by the name of the wheel-bug, can, like them, communicate an electric shock to the person whose flesh it touches. The late Major-general Davies, of the Royal Artillery, well known as a most accurate observer of nature and an indefatigable collector of her treasures, as well as a most admirable painter of them, once informed me, that when abroad, having taken up this animal and placed it upon his hand, it gave him a considerable shock, as if from an electric jar, with its legs, which he felt as high as his shoulders; and, dropping the creature, he observed six marks upon his hand where the six feet had stood.

You may now possibly think that I have nearly gone through the catalogue of our personal assailants of the insect tribes. If such, however, is your expectation, I fear you will be disappointed, since I have many more, and some tremendous ones, to enumerate: but as a small compensation for such a detail of evils and injuries to which our species is exposed from foes seemingly so insignificant, and of acts of rebellion of the vilest and most despised of our subjects against our boasted supremacy, the objects to which I shall next call your attention are not, like most of our apterous enemies, calculated to excite disgust and nausea when we see them or speak of them; nor do they usually steal upon us during the silent hours of repose, (though I must except here the gnat or mosquito,) but are many of them very beautiful, and boldly make their attack upon us in open day, when we are best able to defend ourselves. Borne on rapid wings, wherever they find us, they endeavour to lay us under contribution, and the tribute they exact is our blood. Wonderful and various are the weapons that enable them to enforce their demand. What would you think of any large animal that should come to attack you with a tremendous apparatus of knives and lancets issuing from its mouth? Yet such are the instruments by means of which the fire-eyed and blood-thirsty horse-fly (Tabanus, L.) makes an incision in your flesh; and then, forming a siphon of them, often carries off many drops of your blood[162]. The pain they inflict, when they open a vein, is usually very acute. A fly of this kind not only occasioned Mr. Sheppard considerable pain by its bite, but also produced swelling and blackness round one eye; and the flesh of his cheek and chin was so enlarged from it as to hang down. And Mr. W. S. MacLeay thus describes to me the annoyance he suffered from one of them. "I went down the other day to the country, and was fairly driven out of it by the Hæmatopota pluvialis, which attacked me with such fury, that although I did not at last venture beyond the door without a veil, my face and hands were swelled to that degree as to be scarcely yet recovered from the effects of their venom. I was obliged on my return to town to stay two days at home. Whenever this insect bites me it has this effect, and I have never been able to discover any remedy for the torture it puts me to." In this country, however, the attacks of these flies are usually not frequent enough to make them more than a minor "misery of human life;" but the burning-fly (brulot) or sand-fly of America[163] and the West Indies, which seem to be the same insect, causes a much more intolerable anguish, which has been compared to what a red-hot needle or a spark of fire would occasion us to endure. Lambert, in his Travels through Canada, &c. says, "They are so very small as to be hardly perceptible in their attacks; and your forehead will be streaming with blood before you are sensible of being amongst them[164]."—Yet we have one species (Stomoxys calcitrans) alluded to in a former letter as so nearly resembling the common house-fly[165], which, though its oral instruments are to appearance not near so tremendous, is a much greater torment than the horse-fly. This little pest, I speak feelingly, incessantly interrupts our studies and comfort in showery weather, making us even stamp like the cattle by its attacks on our legs; and, if we drive it away ever so often, returning again and again to the charge. In Canada they are infinitely worse. "I have sat down to write," says Lambert, (who though he calls it the house-fly is evidently speaking of the Stomoxys,) "and have been obliged to throw away my pen in consequence of their irritating bite, which has obliged me every moment to raise my hand to my eyes, nose, mouth, and ears in constant succession. When I could no longer write, I began to read, and was always obliged to keep one hand constantly on the move towards my head. Sometimes in the course of a few minutes I would take half a dozen of my tormentors from my lips, between which I caught them just as they perched[166]."

The swallow-fly (Craterina Hirundinis[167]), whose natural food is the bird after which it is named, has been known to make its repast on the human species. One found its way into a bed of the Rev. R. Sheppard, where it first, for several nights, sorely annoyed a friend of his, and afterwards himself, without their suspecting the culprit. After a close search, however, it was discovered in the form of this fly, which, forsaking the nest of the swallow, had by some chance taken its station between the sheets, and thus glutted itself with the blood of man.—In travelling between Edam and Purmerend in North Holland (July 21, 1815), in an open vehicle, I was much teased by another bird-fly (Ornithomyia avicularia) (two individuals of which I caught) alighting upon my head, and inserting its rostrum into my flesh.—Mr. Sheppard remarks, as a reason for this dereliction of their appropriate food, that no sooner does life depart from the bird that these flies infest, than they immediately desert it and take flight, alighting upon the first living creature that they meet with; which if it be not a bird they soon quit, but, as it should seem from the above facts, not before they have made a trial how it will suit them as food.

But of all the insect-tormentors of man, none are so loudly and universally complained of as the species of the genus Culex, L., whether known by the name of gnats or mosquitos[168]. Pliny, after Aristotle, distinguishes well between Hymenoptera and Diptera, when he says the former have their sting in their tail, and the latter in their mouth; and that to the one this weapon is given as the instrument of vengeance, and to the other of avidity[169]. But the instrument of avidity in the genus of which I am speaking, is even more terrible than that of vengeance in most insects that are armed with it: like the latter also, as appears from the consequent inflammation and tumour, it instills into its wound a poison; the principal use of which, however, is to render the blood more fluid and fitter for suction. This weapon, which is more complex than the sting of hymenopterous insects, consisting of five pieces besides the exterior sheath, some of which seem simply lancets, while others are barbed like the spicula of a bee's sting, is at once calculated for piercing the flesh and forming a siphon adapted to imbibe the blood[170]. There are several species of this genus whose bite is severe, but none is to be compared to the common gnat (Culex pipiens, L.), if, as has been generally affirmed, it be synonymous with the mosquito (though perhaps several species are confounded under both names); and to this, the most insatiable of blood-suckers, I shall principally direct your attention[171].

In this country they are justly regarded as no trifling evil; for they follow us to all our haunts, intrude into our most secret retirements, assail us in the city and in the country, in our houses and in our fields, in the sun and in the shade: nay, they pursue us to our pillows, and either keep us awake by the ceaseless hum of their droning pipe, and their incessant endeavours to fix themselves upon our face, or some uncovered part of our body; or, if in spite of them we fall asleep, awaken us by the acute pain which attends the insertion of their oral stings; attacking with most avidity the softer sex, and trying their temper by disfiguring their beauty. But although with us they are usually rather teasing than injurious; yet upon some occasions they have approached nearer to the character of a plague, and emulated with success the mosquitos of other climates. Thus, we are told that in the year 1736 they were so numerous, that vast columns of them were seen to rise in the air from Salisbury cathedral, which at a distance resembled columns of smoke, and occasioned many people to think that the cathedral was on fire. A similar occurrence, in like manner giving rise to an alarm of the church being on fire, took place in July 1812 at Sagan in Silesia[172]. In the following year at Norwich, in May, at about six o'clock in the evening, the inhabitants of that city were alarmed by the appearance of smoke issuing from the upper window of the spire of the cathedral, for which at the time no satisfactory account could be given, but which was most probably produced by the same cause. And in the year 1766, in the month of August, they appeared in such incredible numbers at Oxford as to resemble a black cloud, darkening the air and almost totally intercepting the beams of the sun. One day, a little before sun-set, six columns of them were observed to ascend from the boughs of an apple-tree, some in a perpendicular and others in an oblique direction, to the height of fifty or sixty feet. Their bite was so envenomed, that it was attended by violent and alarming inflammation; and one when killed usually contained as much blood as would cover three or four square inches of wall[173]. Our great poet Spenser seems to have witnessed a similar appearance of them, which furnished him with the following beautiful simile:

As when a swarme of gnats at eventide
Out of the fennes of Allan doe arise,
Their murmuring small trumpets sownden wide,
Whiles in the air their clust'ring army flies,
That as a cloud doth seem to dim the skies;
Ne man nor beast may rest or take repast
For their sharp wounds and noyous injuries.
Till the fierce northern wind with blust'ring blast
Doth blow them quite away, and in the ocean cast.

In Marshland in Norfolk, as I learn from a lady who had an opportunity of personal inspection, the inhabitants are so annoyed by the gnats, that the better sort of them, as in many hot climates, have recourse to a gauze covering for their beds, to keep them off during the night. Whether this practice obtains in other fen districts I do not know.

But these evils are of small account compared with what other countries, especially when we approach the poles or the line, are destined to suffer from them; for there they interfere so much with ease and comfort, as to become one of the worst of pests and a real misery of human life. We may be disposed to smile perhaps at the story Mr. Weld relates from General Washington, that in one place the mosquitos were so powerful as to pierce through his boots[174] (probably they crept within the boots): but in various regions scarcely any thing less impenetrable than leather can withstand their insinuating weapons and unwearied attacks. One would at first imagine that regions where the polar winter extends its icy reign would not be much annoyed by insects: but however probable the supposition, it is the reverse of fact, for nowhere are gnats more numerous. These animals, as well as numbers of the Tipulariæ of Latreille, seem endowed with the privilege of resisting any degree of cold, and of bearing any degree of heat. In Lapland their numbers are so prodigious as to be compared to a flight of snow when the flakes fall thickest, or to the dust of the earth. The natives cannot take a mouthful of food, or lie down to sleep in their cabins, unless they be fumigated almost to suffocation. In the air you cannot draw your breath without having your mouth and nostrils filled with them; and unguents of tar, fish-grease, or cream; or nets steeped in fetid birch-oil, are scarcely sufficient to protect even the case-hardened cuticle of the Laplander from their bite[175]. In certain districts of France, the accurate Reaumur informs us that he has seen people whose arms and legs have become quite monstrous from wounds inflicted by gnats; and in some cases in such a state as to render it doubtful whether amputation would not be necessary[176]. In the neighbourhood of the Crimea the Russian soldiers are obliged to sleep in sacks to defend themselves from the mosquitos; and even this is not a sufficient security, for several of them die in consequence of mortification produced by the bites of these furious blood-suckers. This fact is related by Dr. Clarke, and to its probability his own painful experience enabled him to speak. He informs us that the bodies of himself and his companions, in spite of gloves, clothes, and handkerchiefs, were rendered one entire wound, and the consequent excessive irritation and swelling excited a considerable degree of fever. In a most sultry night, when not a breath of air was stirring, exhausted by fatigue, pain, and heat, he sought shelter in his carriage: and, though almost suffocated, could not venture to open a window for fear of the mosquitos. Swarms nevertheless found their way into his hiding-place; and, in spite of the handkerchiefs with which he had bound up his head, filled his mouth, nostrils, and ears. In the midst of his torment he succeeded in lighting a lamp, which was extinguished in a moment by such a prodigious number of these insects, that their carcases actually filled the glass chimney, and formed a large conical heap over the burner. The noise they make in flying cannot be conceived by persons who have only heard gnats in England. It is to all that hear it a most fearful sound[177]. Travellers and mariners who have visited warmer climates give a similar account of the torments there inflicted by these little demons. One traveller in Africa complains that after a fifty miles journey they would not suffer him to rest, and that his face and hands appeared, from their bites, as if he was infected with the small-pox in its worst stage[178]. In the East, at Batavia, Dr. Arnold, a most attentive and accurate observer, relates that their bite is the most venomous he ever felt, occasioning a most intolerable itching, which lasts several days. The sight or sound of a single one either prevented him from going to bed for a whole night, or obliged him to rise many times. This species, which I have examined, is distinct from the common gnat, and appears to be nondescript. It approaches nearest to C. annulatus, but the wings are black and not spotted. And Captain Stedman in America, as a proof of the dreadful state to which he and his soldiers were reduced by them, mentions that they were forced to sleep with their heads thrust into holes made in the earth with their bayonets, and their necks wrapped round with their hammocks[179].

From Humboldt also we learn that "between the little harbour of Higuerote and the mouth of the Rio Unare the wretched inhabitants are accustomed to stretch themselves on the ground, and pass the night buried in the sand three or four inches deep, leaving out the head only, which they cover with a handkerchief." This illustrious traveller has given an account in detail of these insect plagues, by which it appears that amongst them there are diurnal, crepuscular, and nocturnal species, or genera: the Mosquitos or Simulia flying in the day; the Temporaneros, probably a kind of Culex, flying during twilight; and the Zancudos or Culices in the night. So that there is no rest for the inhabitants from their torment day or night, except for a short interval between the retreat of one species and the attack of another. We learn from this author that the sting or bite of the Simulium is as bad as that of the Stomoxys before noticed[180].

It is not therefore incredible that Sapor, king of Persia, as is related, should have been compelled to raise the siege of Nisibis by a plague of gnats, which attacking his elephants and beasts of burthen, so caused the rout of his army, whatever we may think of the miracle to which it was attributed[181]; nor that the inhabitants of various cities, as Mouffet has collected from different authors[182], should, by an extraordinary multiplication of this plague, have been compelled to desert them; or that by their power to do mischief, like other conquerors who have been the torment of the human race, they should have attained to fame, and have given their name to bays, towns, and even to considerable territories[183].

And now, which seems to you the greater terror, that the forest should resound with the roar of the lion or the tiger, or with the hum of the gnat? Which evil is most to be deprecated, the neighbourhood of these ferocious animals, terrible as they are for their cruelty and strength, or to live amidst the polar or tropical myriads of mosquitos, and be subject to the torture of their incessant attacks? When you consider that from the one, prudence and courage may secure or defend us without any material sacrifice of our daily comforts; while to be at rest from the other, we must either render ourselves disgusting by filthy unguents, or be suffocated by fumigations, or be content to be bound, head, hand and foot, shut out from the respiration of the common air, and even thus scarcely escape from their annoyance; you will feel convinced that the former is the more tolerable evil of the two, and be inclined to think that those cities, from which the lions were driven away by the more powerful gnats, were no great gainers by the exchange[184]. With what grateful hearts ought the privileged inhabitants of these happy islands to acknowledge and glorify the goodness of that kind Providence which has distinguished us from the less favoured nations of the globe, by what may be deemed an immunity from this tormenting pest! for the inroads which they make on our comfort, when contrasted with what so many other people of every climate suffer from them, are mere nothings. When we behold on one side of us the ravages of the wide-wasting sword, on another those of infectious disease or pestilence, on a third famine destroying its myriads, and on a fourth life rendered uncomfortable by the terror of "noisome beasts," and the attack of noxious insects: and when we look at home and see every one eating his bread in peace, protected in his enjoyments by equal laws executed by a mild government under a paternal king, without fearing the sword of the oppressor; not scourged by pestilence or famine, exposed to the attack of no ferocious animal, and comparatively speaking but slightly visited by the annoyance of insect tormentors; and especially when we further reflect that it is his mercy and not our merits which has induced him thus to overwhelm us with blessings, while other countries have been made to drink deep of the cup of his fury, we shall see reason for an increased degree of thankfulness and gratitude, and, instead of repining, be well content with our lot, though our offences have not wholly been passed over, and we have been "beaten with few stripes."

Besides the insects that seek to make us their food, there are others, which, although we are apt to regard them with the greatest horror, do not attack us with this view, but usually to revenge some injury which they have received, or apprehend from us. Foremost in the list of these are those with four wings, which, according to the observation of Pliny before quoted, carry their weapon, an instrument of revenge, in their tail. These all belong to the Linnean order Hymenoptera; and the tremendous arms with which they annoy us, are two darts finer than a hair, furnished on their outer side at the end with several barbs not visible to the naked eye, and each moving in the groove of a strong and often curved sheath, frequently mistaken for the sting, which, when the darts enter the flesh, usually injects a drop of subtle venom, furnished from a peculiar vessel in which it is secreted, into the wound, occasioning, especially if the darts be not extracted, a considerable tumour, accompanied by very acute pain. Many insects are thus armed and have this power. Twice I have been stung by an Ichneumon; first by one with a concealed sting, and afterwards by another of the family of Pimpla Manifestator, with a very long exerted one. I had held the insect by its sting, which it withdrew from between my fingers with surprising force, and then, as if in revenge, stung me. Pompilus viaticus, one of the spider-wasps, once, in this way, gave me acute pain. Mr. W. S. MacLeay states that at the Havana he was once stung by a gigantic Pompilus (probably P. Heros), from which he suffered a very short-lived pain, but the wound bled as if punctured by a pin. The bleeding he conjectures carried off the venom. But the insects which in this respect principally attract our notice by exciting our fears, are the hive-bee, the wasp, and the hornet. The first of these, the bee, sometimes manifests an antipathy to particular individuals, whom it attacks and wounds without provocation; but the two last, though apparently the most formidable, are not so ill-tempered as they are conceived to be, seldom molesting those who do not first interfere with or disturb them. We learn from Scripture that the hornet (but whether it was the common species is uncertain) was employed by Providence to drive out the impious inhabitants of Canaan, or subdue them under the hand of the Israelites[185].—The effect produced by the sting of these animals is different in different persons. To some they occasion only a very slight inconvenience or a momentary pain; others feel the smart of the wounds which they inflict for several days, and are thrown into fevers by them; and to some they have even proved fatal[186]. Yet these insects are certainly, in general, but a trifling evil. They become, however, especially wasps, a very serious one to many, from the mere dread of being stung by them, even though they should not carry their fears to the same length with the lady mentioned by Dr. Fairfax[187], in the Philosophical Transactions, who had such a horror of them, that during the season in which they abound in houses, she always confined herself to her apartment.

Ants are insects of this order, which, though our indigenous species may be regarded as harmless, in some countries are gifted with double means of annoyance, both from their sting and their bite. A green kind in New South Wales was observed by Sir Joseph Banks to inflict a wound scarcely less painful than the sting of a bee[188]. Another, from the intolerable anguish occasioned by its bite, which resembles that produced by a spark of fire, and seems attended by venom, is called the fire-ant. Captain Stedman relates that this caused a whole company of soldiers to start and jump about as if scalded with boiling water; and its nests were so numerous that it was not easy to avoid them[189]. We are told of a third species, which emulates the scorpion in the malignity of its sting or bite[190]. Knox, in his account of Ceylon, mentions a black ant, called by the natives Coddia, which he says "bites desperately, as bad as if a man were burnt by a coal of fire; but they are of a noble nature, and will not begin unless you disturb them." The reason the Cinghalese assign for the horrible pain occasioned by their bite is curious, and will serve to amuse you. "Formerly these ants went to ask a wife of the Noya, a venomous and noble kind of snake; and because they had such a high spirit to dare to offer to be related to such a generous creature, they had this virtue bestowed upon them, that they should sting after this manner. And if they had obtained a wife of the Noya, they should have had the privilege to sting full as bad as he[191]." Stedman's story of a large ant that stripped the trees of their leaves, to feed, as was supposed, a blind serpent under ground[192], is somewhat akin to this: as is also another, related to me by a friend of mine, of a species of Mantis, now in my cabinet, taken in one of the Indian islands, which, according to the received opinion amongst the natives, was the parent of all their serpents. Whence, unless perhaps from their noxious qualities, could this idea of a connexion between insects and these reptiles be derived? But to return from this digression——Madame Merian's Ant of Visitation (Œcodoma cephalotes) will be considered in a subsequent letter: but I cannot here omit a circumstance mentioned by Don Felix de Azara, a late Spanish traveller, who confirms her account,—that these animals are so alarming and tremendous in their attacks, that if they enter a house in the night, the inhabitants are obliged to rise with all speed and run off in their shirts.

I must next direct your attention to an insect, which perhaps more than any other has in every age been an object of terror and abhorrence—I mean the redoubted scorpion. And though I shall not, with Aristotle, tell you of Persian kings employing armies for several days in destroying them; or, with Pliny, of countries that they have depopulated; yet my account will not be devoid of that species of interest which the dread of its power to do us injury imparts to any object. Could you see one of these ferocious animals, perhaps a foot in length, a size to which they sometimes attain, advancing towards you in their usual menacing attitude, with its claws expanded, and its many-jointed tail turned over its head; were your heart ever so stout, I think you would start back and feel a horror come across you; and, though you knew not the animal, you would conclude that such an aspect of malignity must be the precursor of malignant effects. Nor would you be mistaken, as you will presently see. This alarming animal, though like hymenopterous insects it is armed with a sting, is in no respect related to that order, and forms the only genus, at present known, of the others that is so armed. Even its sting is totally different from that of bees, wasps, and other Hymenoptera, being more analogous to the venomous tooth of serpents; it wounds us with no barbed darts concealed in a sheath, but only with a simple incurved mucro terminating an ampullaceous joint. Two orifices, or according to some three, are said to instill the poison, which, we are informed, is sometimes as white as milk. This venom in our European species is seldom attended, except to minor animals, by any very serious consequences; yet when it is communicated by the scorpion of warmer climates it produces more baneful effects. The sting of certain kinds common in South America causes fevers, numbness in various parts of the body, tumours in the tongue, and dimness of sight, which symptoms last from twenty-four to forty-eight hours. The only means of saving the lives of our soldiers who were stung by them in Egypt, was amputation. One species is said to occasion madness; and the black scorpion, both of South America and Ceylon, frequently inflicts a mortal wound[193]. No known animal is more cruel and ferocious in its manners; they kill and devour their own young without pity as soon as they are born, and they are equally savage to their fellows when grown up. Terrible however and revolting as these creatures appear, we are gravely told by Naudé, that there is a species of scorpion in Italy which is domesticated, and put between the sheets to cool the beds during the heats of summer[194]!!

I must next say something of insects that annoy us solely by their jaws. Of this description is Galeodes araneoides which is related to the scorpion, although devoid of a sting. The bite of this animal, which is a native of the Cape of Good Hope and of Russia[195], is represented to be often fatal both to man and beast. Another species of Galeodes is described by Professor Lichtenstein, which, from the trivial name that he has given it (fatalis), may be supposed to be as venomous as the former[196].

The bite of one of the centipedes (Scolopendra morsitans)—the under-jaws, or rather arms, of which are armed with a strong claw, furnished like the sting of the scorpion with an orifice, visible under a common lens[197], from which poison issues—is less tremendous than that of the animal last mentioned: but though not mortal, its wounds are more painful than those produced by the sting of the scorpion; and as these animals creep every where, even into beds, they must be very annoying in warm climates where they abound. Dr. Martin Lister, in his Travels, has given us a figure of an insect related to this genus, that he saw in Plumier's collection, which appears to have been eighteen inches in length, and three quarters of an inch in width, having ninety-five legs on each side, the first eight of which are armed with double claws, and two inches of the tail being without legs. It may form a distinct genus, and is probably a native of South America. Yet even this monstrous insect is nothing to those at Carthagena, mentioned by Ulloa, (if indeed we may credit his account, or if his translator has not mistaken his meaning,) which sometimes exceeded a yard in length and five inches in breadth! The bite of this gigantic serpent-like creature, he tells us, is mortal, as well it may, if a timely remedy be not applied. From its cylindrical form it should be a Julus[198].

In this catalogue of noxious insects I must not omit those which every where force themselves upon our notice, and are viewed with general disgust. I mean the numerous family of Arachne, the insidious spiders. Few of these, however, are really personal assailants of man. The principal is that which has given rise to so much discussion, and has so much employed the pens of naturalists and physicians—the famous Tarentula (Lycosa Tarentula). The effects ascribed to its wounds, and their wonderful cure supposed to be wrought by music and dancing, have long been celebrated: but after all there seems to have been more of fraud than of truth in the business; and the whole evil appears to consist in swelling and inflammation. Dr. Clavitio submitted to be bitten by this animal, and no bad effects ensued; and the Count de Borch, a Polish nobleman, bribed a man to undergo the same experiment, in whom the only result was a swelling in the hand, attended by intolerable itching. The fellow's sole remedy was a bottle of wine, which charmed away all his pain without the aid of pipe and tabor[199].

There is however a spider (Theridium 13-guttatum) the bite of which is said to be very dangerous, and even mortal. Thiébaut de Berneaud, in his Voyage to Elba[200], affirms that in the Volterrano he knew that several country people and domestic animals died in consequence of it. And according to Mr. Jackson, a spider, called there the Tendaraman, is found in Marocco which has venomous powers equally formidable. The bite of this insect, which is about the size and colour of a hornet but rounder, and spins a web so fine as to be almost invisible, is said to be so poisonous that the person bitten survives but a few hours. In the cork forests the sportsman, eager in his pursuit of game, frequently carries away on his garments this fatal insect, which is asserted always to make towards the head before inflicting its deadly wound[201].

I suspect you will think this list long enough; and I believe it includes the most remarkable insects that assail the surface of our bodies, to answer either the demands of hunger or the stimulus of revenge. There is however a third class of insect annoyers, as I observed at the beginning of this letter, which, though they neither make us their food, nor attack us under the impulse of fear or revenge, incommode us extremely in other ways. These must now be detailed to you.

How extremely unpleasant is the sensation which that very minute fly, Thrips physapus, excites in sultry weather, merely by creeping over our skin! I have sometimes found this almost intolerable. A similar torment reckoned by Ulloa a kind of Mosquito, infests the inhabitants of Carthagena in South America. They are there called Mantas blancas, and creeping between the threads of the gauze curtains that keep off the former pest, though they do not bite, occasion an itching that is dreadfully tormenting[202]. But these are nothing compared with the teasing attacks of another gnat (Simulium reptans), which, as Linné informs us, who misnamed it a Culex, is so incredibly numerous in Lapland, as entirely to cover a man's body, turning a white dress into a black one, occupying the whole atmosphere, filling the mouth, nostrils, eyes, and ears of travellers, and thus preventing respiration, and almost choking them. These little animals, he says, do not bite, but torture incessantly by their titillation[203].—In New South Wales a small ant was observed by Sir Joseph Banks, inhabiting the roots of a plant, which when disturbed rushed out by myriads, and running over the uncovered parts of the body produced a sensation of this kind that was worse than pain.

The common house-fly is with us often sufficiently annoying at the close of summer; but we know nothing of it as a tormentor compared with the inhabitants of southern Europe.—"I met (says Arthur Young in his interesting Travels through France) between Pradelles and Thuytz, mulberries and flies at the same time; by the term flies I mean those myriads of them which form the most disagreeable circumstance of the southern climates. They are the first torments in Spain, Italy, and the Olive district of France: it is not that they bite, sting, or hurt, but they buzz, tease, and worry: your mouth, eyes, ears, and nose, are full of them: they swarm on every eatable,—fruit, sugar, milk, every thing is attacked by them in such myriads, that if they are not incessantly driven away by a person who has nothing else to do, to eat a meal is impossible. They are however caught on prepared paper and other contrivances with so much ease and in such quantities, that were it not from negligence, they could not abound in such incredible quantities. If I farmed in these countries, I think I should manure four or five acres every year with dead flies.—I have been much surprised that the late learned Mr. Harmer should think it odd to find, by writers who treated of southern climates, that driving away flies was an object of importance. Had he been with me in Spain and in Languedoc in July and August, he would have been very far from thinking there was any thing odd in it[204]."

Our friend Captain Green, of the sixth regiment of the East India Company's native troops, relates to me, that in India, when the mangoes are ripe, which is the hottest part of the summer, a very minute black fly makes its appearance, which, because it flies in swarms into the eyes, is very troublesome, and causes much pain, is called there the eye-fly. At this season the eyes are attacked by a disease, supposed to be occasioned by eating the mangoes, but more probably the result of the irritation produced by the fly in question, which, however, they admit, carries the infection from one person to another.

You know that the hairs taken from the pods of Dolichos pruriens and urens, L., commonly called Cowhage and Cow-itch[205], occasion a most violent itching, but perhaps are not aware that those of the caterpillars of several Moths will produce the same disagreeable effect. One of these is the procession moth, (Lasiocampa processionea) of which Reaumur has given so interesting an account. In consequence of their short stiff hairs sticking in his skin, after handling them, he suffered extremely for several days; and being ignorant at first of the cause of the itching, and rubbing his eyes with his hands, he brought on a swelling of the eye-lids, so that he could scarcely open them. Ladies were affected even by going too near the nest of the animal, and found their necks full of troublesome tumours, occasioned by short hairs, or fragments of hair, brought by the wind[206]. Of this nature also is the famous Pityocampa of the ancients, the moth of the fir (Lasiocampa Pityocampa), the hairs of which are said to occasion a very intense degree of pain, heat, fever, itching and restlessness. It was accounted by the Romans a very deleterious poison, as is evident from the circumstance of the Cornelian law "De sicariis" being extended to persons who administered Pityocampa[207].

In these cases the injury is the consequence of irritation produced by the hair of the animal; but there are facts on record, which prove that the juices of many insects are equally deleterious. Amoreux, from a work of Turner, an English writer on cutaneous diseases, has given the following remarkable history of the ill effects produced by those of spiders. When Turner was a young practitioner, he was called to visit a woman, whose custom it was, every time she went into the cellar with a candle, to burn the spiders and their webs. She had often observed, when she thus cruelly amused herself, that the odour of the burning spiders had so much affected her head, that all objects seemed to turn round, which was occasionally succeeded by faintings, cold sweats, and slight vomitings: but, notwithstanding this, she found so much pleasure in tormenting these poor animals, that nothing could cure her of this madness, till she met with the following accident: The legs of one of these unhappy spiders happened to stick in the candle, so that it could not disengage itself; and, the body at length bursting, the venom was ejaculated into the eyes and upon the lips of its persecutrix. In consequence of this, one of the former became inflamed, the latter swelled excessively, even the tongue and gums were slightly affected, and a continual vomiting attended these symptoms. In spite of every remedy the swelling of the lips continued to increase, till at length an old woman, by the simple application for fifteen days of the leaves and juice of plantain, together with some spider's web, ran away with all the glory of the cure[208]. Ulloa gives us a remarkable account of a species of spider, or perhaps mite, of a fiery red colour, common in Popayan, called Coya or Coyba, and usually found in the corners of walls and among the herbage, the venom of which is of such malignity, that on crushing the insect, if any fall on the skin of either man or beast, it immediately penetrates into the flesh, and causes large tumours, which are soon succeeded by death. Yet, he further observes, if it be crushed between the palms of the hands, which are usually callous, no bad consequence ensues. People who travel along the valleys of the Neyba, where these insects abound, are warned by their Indian attendants, if they feel any thing stinging them, or crawling on their neck or face, not so much as to lift up their hand to the place, the texture of the Coya being so delicate that the least force causes them to burst, without which there is no danger, as they seem otherwise harmless animals. The traveller points out the spot where he feels the creature to one of his companions, who, if it be a Coya, blows it away. If this account does not exaggerate the deleterious quality of the juices of this insect, it is the most venomous animal that is known; for he describes it as much smaller than a bug. The only remedy to which the natives have recourse for preventing the ill effects arising from its venom is, on the first appearance of the swelling, to swing the patient over the flame of straw or long grass, which they do with great dexterity: after this operation he is reckoned to be out of danger[209].—The poisoned arrows which Indians employ against their enemies have been long celebrated. The Coya may, in the western world, have furnished the poison for this purpose. An author quoted in Lesser tells us that an ant as big as a bee is sometimes used, and that the wound inflicted by weapons tinctured with their venom is incurable. Patterson also gives a recipe by which the natives of the southern extremity of Africa prepare what they reckon the most effectual poison for the point of their arrows. They mix the juice of a species of Euphorbia, and a caterpillar that feeds on a kind of sumach (Rhus, L.), and when the mixture is dried it is fit for use[210].

And now I think you will allow that I have made out a tolerable list of insects that attack or annoy man's body externally, and a sufficiently doleful history of them. That the subject, however, may be complete, I shall next enumerate those that, not content with afflicting him with exterior pain or evil, whether on the surface or under the skin, bore into his flesh, descend even into his stomach and viscera; derange his whole system, and thus often occasion his death. The punitive insects here employed are usually larvæ of the various orders, and they are the cause of that genus of diseases I before noticed, and proposed to call Scolechiasis.