ABRIDGMENT OF THE CONTEMPLATION OF NATURE
BY Mr. Bonnet, of GENEVA

CHAPTER VIII
OF ANIMAL ECONOMY, CONSIDERED IN INSECTS

  I. The sketch I have lately drawn of animal economy, affords a slight idea of what constitutes the essence of life in most animals.. We shall now treat of the principal varieties which the organizations of different species presents us with. Insects, hitherto little known,. exhibit some singularities in this very, respect, to which we shall. confine ourselves by way of preference, in order to avoid such details as might carry us to too great a length.

We have already seen, in some measure, the different parts con­tained in the composition of these little machines: we will now con­template their exercise and various effects.

2. The mechanism of respiration is very obscure in insects. We only know that in them it differs greatly from that in those animals which are most known to us. But we judge with greater certainty concerning this difference by the comparison of the organs, than by that of their exercise. When a drop of greasy liquor is applied to one or several stigmata of an insect, the corresponding parts become paralytic. The interception of the air in one part is followed by that of liquors or spirits. When we stop up all the stigmata, the insect dies immediately. If we afterward open them, we shall perceive the inside to revive. The air, which then penetrates the open orifices of the tracheas, evidently produces this kind of resurrection.

The tracheae or air vessels, are divided and sub-divided in a prodigious degree. May they not resemble so many sieves, which by separations suitably contrived, are capable of furnishing to each part an air of a more or less subtle nature, as occasion requires? There are commonly reckoned to be nine stigmata on each side of the body: but sometimes there are more in number, at others fewer. The same insect has some that are of greater or less importance to it, or whose functions are more or less necessary. In several species, the principal stigmata are placed behind: in others at the head. In­stead of stigmata, they are pretty frequently observed to have little tubes of different lengths.

3. The circulation of the blood is performed in insects with great regularity. We trace it by our sight, in some species of long and transparent worms. We may see the heart, or principal artery, con. tract and dilate itself successively in every part of its extent. It seems to be composed of a great number of little hearts, placed end to end, that transmit the blood to each other.

We are yet ignorant in what manner the blood is conveyed into the grand artery Its principal ramifications, and the canals analogous to veins, are equally unknown. We are only certain, that in many species, for the most part of the creeping sort, the principal of cir­culation is towards the hinder part, whereas, in others, it is towards the head. It is very probable that the grand artery shoots forth, from both sides of it, several branches that are invisible, by reason of their extreme fineness or transparency, and that distributes the blood to every part. Other branches are without doubt connected with them, and conduct the residue of the blood to the principal trunk of veins, which is imagined to be perceived on the opposite side of the heart. The blood of insects is a subtle liquor, transparent, com­monly without colour, and though it be not in the least inflammable, resists in some species, a degree of cold, superior to that of our seve­rest winters.

4. The organs of generation, in most insects, are placed at the extremity of the belly. That which characterizes the male, consists principally of one or two species of fleshy horns, which are turned different ways, and are generally drawn within the body, but emitted from thence at the pleasure of the insect. The hind part of divers males is also furnished with hooks, by means of which they fasten or that of the females. In the interior part are lodged different vessels, which are connected with the principal organ of generation, and separate the fecundating liquor from the mass of blood. At the end 0f the aperture formed in the female, there is joined a kind of canal, which in many insects, sends forth several branches, called tubes or ovaries. These are species of very fine intestines, in which the eggs are ranged in a row, almost like the beads of a chaplet.

The eggs nearest the aperture are the largest, or in a more advanced state. They gradually diminish according to their distance. At length they become altogether invisible.

In the common passage, where the ovaries terminate, there is inserted, in some species, a very short canal, which communicates with an oblong cavity, that is considered as analogous to the matrix. In this cavity the liquor of the male is deposited.

Amongst viviparous animals the economy of the tubes changes. Sometimes the young are ranged in bunches. At others they form a kind of cord twisted spirally, whose length, width, and thickness exactly correspond in number to the length and thickness of the young that compose it. The young of some viviparous insects, before they are brought forth, tear the membrane or ovary that encloses them; they are, to use the expression, on this account subject to a two-fold birth.

The eggs of insects are of two kinds: some are membraneous, like those of tortoises and reptiles : others are crustaceous, as are those of birds. But whereas in large animals the species comprised under these genera differ only from each other by a slender variety; amongst insects these varieties are so great, that one animal does not differ more from another, than one of their eggs does from another. Some of them are round, elliptical, lenticular, cylindrical, pyramidical, flat. Some are quite smooth, others grooved or channelled. In short, what is more extraordinary, there are some eggs that grow after they are laid. We easily judge that they are entirely membra­anus. The suppleness of their membranes admits of their exten­sion. They have pores that imbibe the juices of the plant where they are deposited. These are minute placentice that transmit the nourishment to the embryo.

5. The distinction of insects into viviparous and oviparous does not only take place in species of different classes, but likewise in species of the same germs. There are some two winged flies that are vivi­parous, and others that are oviparous.

Add to this, that some species are viviparous, at one time and oviparous at another. The vine-fretter furnishes an example of this.

All great animals that are known to us, are distinguished into males and females, and propagate the species by copulation. The same order prevails amongst insects; but all the species are not subject to it, and, of those that are, several afford some very remarkable singularities. In divers species the male is winged, and the female not. The glow-worm which is sentenced to crawl during its whole life time, is fecundated by an insect having four wings.

Sometimes this striking singularity is joined with others that are still more surprising. Every where else we observe a certain pro­portion betwixt the male and female ; here this proportion vanishes entirely. The female is a colossus, on which the male walks as on spacious spot. The ardour and agility of the male are excessive. He is almost in continual motion. The female, on the contrary, moves but seldom, and that heavily. She sometimes spends the greatest part of her life in the most perfect inactivity. In fine, the male is an insect properly so called, his whole body is intersected by incisions that are very conspicuous: The female is a spherical mass, fixed to a branch, that one would be apt to take for an excrescence or gall nut of this branch. You will imagine that I am speaking of gall insects, whose name so welt explains their deceitful appearances. They are found in great numbers on the branches of many trees and shrubs. They are greatly diversified; but always affect the form of gall nuts more or less round. They imbibe the juice of the tree by the assistance of a little pump, which they keep fixed to the bark. They lay some thousands of eggs, which are piled up under the mother’s belly, as they-issue from it. When the whole number is laid, the gall insect dies, and its carcase remains-fastened to the branch. This is only a cod full of eggs, which one might still take for a living gall insect, so small an appearance of life is there in this strange ani­mal. The young are hatched in a short time, when there immediately appears a multitude of very small animated membranes, either oval or circular, which are borne on six legs, and disperse themselves on all sides with a wonderful celerity.

6.  Several of the species that live in society, present us with three sorts of individuals; to wit, males,- females and neuters, or individuals that remain always deprived of sex. This we observe in the republics of bees, ‘wasps, and ants. We know that each swarm of bees has but one female, which bears the name of queen; the males, which are called drones, pretty often amount to four or live hundred; the neuters, which are much more numerous, are sometimes forty or fifty thousand in number. These are the ilotes of the little Sparta; they are charged with all the labour. The queen and drone are wholly taken up in furnishing the state with citizens. She is, in a literal sense, the mother of all her people ; she lays in one year up­wards of fifty thousand eggs. She produces three sorts of them, from. whence are hatched three kinds of individuals of different shape. The neuters then construct three sorts of cells, to receive ‘the eggs, and lodge the young to be hatched from them.

Divers species of insects are real hermaphrodites; in each individual both sexes are united, but he cannot fecundate himself; and generation depends in this case, as elsewhere, on the concurrence of two individuals.

7. Other insects are hermaphrodites of a more singular nature; each individual propagates without any commerce with another. We have the first example of this in the vine-fretter, that deserves some attention.

You have very frequently seen little flies fastened in a great number to the extremities and leaves of plants, and twisting them round in various forms: these are vine-fretters, whose species are almost as numerous as those of vegetables, and whose remarkable properties are multiplied in proportion to the attention we pay them.

They bring forth living young ones. Their births are easy to trace; there needs only good eyes and a little patience. Take up a little one as soon as it is produced: enclose it immediately in the most perfect solitude, and in order to be the better assured, carry your precautions to a degree of scrupulousness; be with respect to it a more vigilant Argus than the fabulous one. When the little recluse has acquired a certain growth, it will begin to have young, and after some days you will find it in the midst of a numerous family.

Make the same experiment on one of the individuals of this flimily that you have tried on its chief: the new hermit will multiply like its father, and this second generation brought up in solitude, will not prove less fruitful than the first.

Repeat the experiment from one generation to another; abate no­thing of your cares, your precautions, and suspicions; proceed, if your patience will permit you, to the ninth generation, and they will all present you with fecund virgins.

After these experiments, so decisive and reiterated, you are easily persuaded that there is no distinction of sex in vine-fretters. What indeed would be the use of such a difference amongst a people where all the individuals are constantly sufficient for themselves ? Natural history is the best logic, because it best teaches us to suspend our judgment. Vine-fretters are really distinguished by sexes; there are males and females amongst them, and their amours are least equivocal of any in the world. I do not know whether there are in nature any males more amorous than they.

What then is the use of coupling between insects that multiply with-out its assistance ? Of what service can an actual distinction of sex be to real androgynes? The clearing tip of this point depends on another great singularity. During the summer season they are viviparous;’ they’ all bring forth living young. Towards the middle of autumn they become ovipurous they all then lay real eggs. which are hatched at the return of the spring. The males begin to appear exactly at the time the females begin to lay. There is therefore a secret relative betwixt the appearance of the males, and the laying of the females, There are always found in the bodies of the females, eggs and ready to be produced. The young then were originally enclosed in eggs. During the fine season, they are hatched in the belly of their mother, and are brought into the world alive. Plants at that time furnish them with a proper nourishment, which they fail not instantly to embibe by the help of a very slender trunk. At the approach of cold weather, the young cannot unfold themselves in the dam's belly, in order to their being produced alive; they remain shut up their eggs, where they are preserved the whole winter. Were they to be hatched at the beginning of that season, they would soon perish for want of food. The developement depends ultimately on nutrition. Vine-fretters that are produced alive, are more unfolded in the matrix than those which are brought forth enclosed in eggs. The former. then have received a nourishment in the matrix, which the others were. not able to obtain there. This nourishment was sufficient to effectuate. the entire opening of the germs. Had not coupling, then, for its pri­mary end, the supplying the defect of this nourishment in such germs as were not to be hatched till after they had issued from the belly of their mother.

I have treated of some species of insects, the males of which are winged, and the females not. This singularity is also to be met with among vine-fretters; but they offer still more to us with respect to this. Some of the males are winged, and others remain their whole life time without wings. There are likewise winged females, and other females that are not. But this is not all: the males, and particularly those that are destitute of wings are so small in compa­rison of the females, that they are seen to walk upon them as a mite upon fruit; to so great a degree has nature thought fit to abound, with regard to these insects, in singularities of different kinds.

8. Animals that multiply by slips and shoots, and that may be grafted appear to be real zoophytes, or plant animals.

Of these some have feet or members, others not. We shall first treat of the latter sort.

The slime which covers the bottom of ponds and marshes may almost be deemed a respectable thing: there the Great Being has not disdained to assemble the traces of his power and wisdom. He has connected the existence of this vile matter with that of different species of worms, that are destined to live in and feed upon it, and that will one time or other present us with the interesting sight of a new reproduc­tion, which we shall never think we can sufficiently admire, and shall therefore wonder at it in proportion as our understanding is enlight­ened.

All these worms are long and slender. They are not unlike the treble string of a violin; their body is formed of the succession of a great number of little rings, which decrease gradually as they approach the extremities. They are very soft: their head, which terminates in a blunt point, is susceptible of various motions. It contracts, dilates, lengthens, and shortens itself at the pleasure of the insect. The mouth is furnished with a muscle that directs the functions of it, and whose  exercise is pretty perceivable. The anus, which is placed at the opposite extremity, is a little oblong aperture, bordered with an analogous muscle. The whole skin is so transparent, as to admit of its being inspected within, and we may congratulate ourselves on this cir­cumstance, since it affords us a great spectacle. The polypus exhibits nothing that has the appearance of the viscera. All its substance seems to be composed of a mass of small similar seeds. Our fiddle-strings are minute beings, quite differently organized, and the apparatus of the viscera, which the microscope discovers to us, seems to advance them far above the polypus. A long vessel that goes winding from the head, to the tail, is what chiefly strikes the eye of the observer, by its regular alternate motions, he will soon know it to be the heart or grand artery. The liquor that circulates in these winding passages is limpid. It is perceived from the pulsations it excites in every part of the artery comprised betwixt two of the rings One would be :tpt to imagine each of these portions to be a real heart, and that every artery was a chain of little hearts, placed end to end, and that forced the blood from one part to another. It is seen to run with an uniform motion through all these little hearts, and rises in this manner; as by so many bladders from the tail to the head, near which it finally disappears. In different parts of the artery are discovered delicate ramifications of vessels, which may be taken for veins, there being perceived no pulsa­tion in them. Beneath and along the artery there is a canal, whose diameter varies at different points of its extent. It is the intestinal duct, which comprehends the oesophagus, stomach, and intestines. The alimentis there seen to digest before the eyes of the observer: he follows it in its passage : sees it descend from the mouth towards the anus, and pass through every part of the canal between these two extremities. But can machines so compounded as these be taken to pieces without injuring their economy thereby?

That suffers not in any respect on that account. Strictly speaking, it affects these insects no more than being divided in the midst of the body. Each half not only continues to live and move: but that which bad no head presently forms another, and we may clearly perceive a new tail spring forth in that part which was destitute of one. In less than three days the two moieties become two complete worms.

It is more extraordinary for fourths, eighths, and sixteenth parts of our worms to assume a head and tail: this is so speedily effected, that in a few days all these fragments are so many insects, and after a few weeks attain to the same length as the entire worm. New rings and new viscera unfold themselves, the parts reproduced differ in no respect from the ancient ones. Thus the machine is formed anew its own strength; and the section, which might be a means of destroying them, serve only to make them conspicuous.

I have not yet sufficiently treated of this particular. The six and twentieth part of worms, to wit, perfect atoms, are able to re-integrate themselves extremely well, and in the space of some months are found to be worms of several inches in length. In these living atoms, as well as in the most considerable fragments, the circulation seems to be per formed with the same regularity as in the whole worm. Each atom has its little heart, and we may clearly perceive that this little heart is no other than a very small portion of the grand artery of the worm;’ whereof the atom was before a part.

We may weary ourselves in cutting the head off the same individual

we shall have the same task to repeat continually, because there always; shoots forth a new one. We may even cause several to issue at the same time, each of which shall have their proper functions.

There is another species of these worms, amongst which the pro­perty of becoming again entire is confined in very remarkable bounds. It forms a head or tail in the middle; but if it be cut into three or four parts, the intermediate ones push forth a tail where a head should have been produced. This supernumerary tail, which is in no res­pect deficient, cannot perform the office of a head, and the unhappy insect is condemned to perish with hunger.

9. Look into this rivulet, whose bottom is covered with broken pieces of plants: what do you perceive upon them? Spots of mouldi­ness. Do not mistake: this mouldiness is not what it appears to be;’ and you already begin to suspect so ; you think that you greatly enno­ble them by advancing them to the rank of vegetables; you conjec­ture they are plants in miniature, that have their flowers and seeds, and plume yourself on being able to judge of these mouldinesses in a different manner from the vulgar. Take a magnifying glass: what do you discover? Some very pretty nosegay, all the flowers of which are in bells. Each bell is supported by a small stalk, which is im­planted in a common one; you now no longer doubt of the truth of your conjecture, and cannot be persuaded to quit this microscopic parterre. You have not however sufficiently observed it. Look steadfastly on the aperture of one of these bells: you will there per­ceive a very rapid motion, which you cannot be weary of contempla­ting, and which you compare to that of a mill. This motion excites little currents in the water, that convey towards the bell a multitude of corpuscles. which it swallows up. You begin to doubt whether these bells are real flowers and the motions of the stalks which appear to be spontaneous, increase your suspicions Continue your observations nature herself will teach you what you ought to think 0f this singular production, and will furnish you with fresh motives for admiring the fecundity of her ways. That is a bell which detaches itself from the clustre, and that floats along in order to fix itself to some support. Follow it. A short pedicle issues from its extremity: and the bell fastens itself by the end of this pedicle. It lengthens and becomes a little stalk. It is no longer a nosegay you are beholding, it is a single flower. Redouble your attention ; you are just arrived at the most interesting moment of inspection. The flower is closed, has lost its form of a bell, and assumed that of a bud. You perhaps suspect that this bud is some fruit, or a seed that has succeeded to the flower: for you are both to give up your first conjecture. Do not lose sight of this bud; it is now divided by degrees according to its length, and the stalk is at present supplied with two buds, less than the first. Examine what passes in both of them. They widen them­selves insensibly, and you perceive a motion at the edge of the open­ing, which increases in swiftness in proportion as the bud unfolds itself The mill appears again, and the two buds have assumed the form of a bell. Can a fruit which changes into flowers, be a real fruit? Can such flowers be real flowers, that swallow little insects? Suspend your observations, and repeat them a few hours hence. Your flowers are closed up as the first was ; you easily guess that they will separate themselves as before, afterward open, and present you with four bells. That is already effected, and you have a little nosegay, composed of four flowers. If you continue your inspection, you will see them augment in bulk by new divisions in two’s, and soon after you will count sixteen, thirty-two, sixty-four flowers. Such is the origin of this microscopical parterre, which at first drew your attention: how much more admirable does it now appear than you then ‘conceived it to be! What a group of wonders does a single spot of mouldiness afford! What unforeseen, varied, and interesting scenes, are trans­acted on a scrap of rotten wood! What a theatre does it exhibit to a thinking being! But our abode is so recluse, that we have but a glim­mering view of it; how great would our ravishment be, if the whole spectacle disclosing itself at once to us, we should be enabled to pene­trate into the interior structure of this wonderful assemblage of liv­ing atoms! Our blunted eyes discover only the most striking parts of them; they only apprehend the gross parts of the decorations, whilst the machines that execute them remain concealed in impenetrable darkness! Who shall enlighten this profound obscurity ? Who shall dive into this abyss where reason itself is lost? Who draw from thence the treasures of wisdom and knowledge concealed within it? Let us learn to be content with the small portion communicated to us, and contemplate with gratitude those first traces of human understanding imparted to us, towards a world placed at such a great distance from us

10. You cannot quit this spring, from whence you have derived many truths that are so astonishing. You discover in it other microscopical animals, whose form resembles that of a funnel. These are likewise polypuses. They do not compose a clustre ; but cleave some body by their inferior extremity ; you are Curious to know their method of multiplying. In order to this, place your microscope one of these funnels. Of a single funnel, there are formed two by a natural division ; but very different from that of bell-polypuses; so far has nature thought fit to vary her proceedings with respect to these animals. Examine what passes in the middle of the funnel. A verse and oblique stripe indicates to you the part where the polypus is about to divide itself. The division then is made slopingly. The stripe points out the edges of the new funnel, and these are only the lips of the fresh polypus. You discover in them a pretty slow motions, which helps you to discern them. They approach each other insensibly, the body collects itself by degrees; a little swelling forms itself. on the side, which is a new head. You already clearly distinguish two polypuses placed above each other. The upper polypus has the former head and a new tail ; the inferior one a new head and the former tail. The upper polypus is connected with the other only by: its lower extremity. By a motion it gives itself, it is at last detached from the other: and floats away in order to fix elsewhere. The infe­rior poly pus remains fastened to the place where the funnel was before the division.

11. Net-polypuses likewise derive their name from the exterior. form of their bodies ; they pretty nearly resemble that of a fishing-net. They assemble in groups, and fasten on all the bodies they meet with. in fresh water. They are very transparent. In the inside of the polypus there is formed an oblong and whitish body. As soon as it is formed, it descends by degrees, shows itself on the outside, and remains fixed perpendicularly on the polypus It produces new ones every day; and the group they compose on the exterior part of the polypus, increases in growth. If these minute bodies be eggs, they are of a singular species; they are absolutely without any covering, and are neither membraneous nor crustaceous. We cannot affirm of these eggs, that young are hatched from them, but are under a neces­sity of acknowledging, that these little oviform bodies unfold them­selves. This developement is accomplished in a few minutes, and the polypus becomes the same as its mother: imagine to yourself a bird that should issue from its mother’s belly, entirely naked, rolled together like a ball, whose members should afterward display themselves, and you will have a representation of the production of net-polypuses.

12. Cluster-polypuses propagate by dividing in the middle; arm-polypuses do not multiply in this manner. They bring forth their young almost as a tree shoots forth its branches. A little bud appears on the side of the polypus. Do not suppose that this bud contains a polypus, as the vegetable bud comprises a branch: it is itself the polypus in its growth. It increases in size and length, and at last separates from its mother. Whilst it is united to her, they both com­pose one body, as the branch with the tree. You are to understand this in the strictest sense. The prey, which the mother swallows, passes immediately into her young, and imparts the same colour to it. So that the whole consists of one little bowel of a great extent. The prey which the young one seizes, (for it fishes for it as soon as it has arms) passes in like manner into the mother. They nourish each other reciprocally.

There is scarcely any polypus without buds. All of them there. fore are so many polypuses, or so many shoots that grow on a com­mon trunk. Whilst they are unfolding, they themselves send forth smaller shoots, and these smaller still. They all extend their arms on both sides. You think you are beholding a very bushy tree. The nourishment received by one of these shoots, is soon communicated to all the rest, and to their common mother; the chief of the society and the members are one. The society is dissolved by little and little, the members separate themselves, are dispersed, and each shoot becomes in its turn, a little genealogical tree.

Such is the natural method by which the arm polypus multiplies. It may also be multiplied by slips. There is no need to mention, that when it is cut in pieces, each piece in a short time becomes a perfect polypus. It were better to say at once, that the polypus, after being cut into small pieces, rises again from its ruins, and the little fragments yield as many polypuses. Being cut either in length or width, this extraordinary animal is reproduced in the same manner, and the sources of life are equally inexhaustible.

13. But the following is what fable itself has not presumed to invent: bring to their trunk the heads that have been struck off, they will reunite to it, and you will restore to the polypus its head. You may also, if you think proper, affix to it the head of another polypus. The mutilated parts of the same or different polypuses, when placed end to end, will unite in like manner, and form only a single polypus.,

What have I hitherto said? There is scarce any miracle that may not be performed by means of the polypus; but miracles, when mul­tiplied to so great a degree, hardly appear to be such. A polypus may be introduced by its hind part into the body of another polypus. The two individuals unite, their beads become ingrafted into each other: and the polypus, which at first was double, is converted into a single polypus, that eats, grows and multiplies.

I have compared the polypus to the finger of a glove: this finger may be turned inside out: so may the polypus likewise, and being so shifted, can fish, swallow, and multiply by slips and shoots.

It will be easily believed that the polypus does not like to remain thus shifted. It makes an effort to regain its former position, and frequently succeeds either in part, or altogether. The polypus, which is partly turned back again as at first, is a real Proteus, that assumes all kinds of forms, which are all equally strange. Endea your to represent to yourself the polypus thus turned again. You remember that the insect is made in the form of a bowel. One part of the bowel then is turned backwards on the other; it there fastens and engrafts itself. In that case, the polypus is as it were doubled. The mouth encompasses the body like a fringed girdle; the arms are the fringe. They then point towards the tail. The fore part continues open; the other is usually shut up. You expect, no doubt, to see a new head and new arms, to grow out of the fore part; which you have observed in all the polypuses that have been divided transversely. But the polypus combines itself a thousand different ways, and each combination has its consequences, which experience alone can discover to you. The fore part closes itself; it it becoming a supernumerary tail. The polypus, which was at first extended in the right line, is curved more and more. The supernu­merary tail lengthens every day. The two tails resemble the feet of a pair of compasses. The compasses are partly open. The ancient mouth is at the head of the compasses. This mouth, which is fastened to the body, and embraces it like a ring, cannot discharge its functions. What then must become oc the unfortunate polypus with two tails and without a head? How will it be able to live? Do you think that you have taken nature at unawares? You are mistaken. Towards the upper part of the polypus, near the ancient lip, there are forming not only a single mouth, but several; and this polypus, concerning which you inquired a minute ago how it could exist, is now a species of hydra, with several heads and mouths, and devours with all these mouths.

14.  What a multitude of physiological truths, that were unknown to us in the vegetable kingdom, has the arm.polypus alone unveiled to us? How do these truths appear as paradoxes, and yet how evi­dently are they demonstrated? Who can doubt now that there exists an animal,* a very animal, since it is extremely voracious, whose young grows like branches, and which being cut to pieces and actually minced, regenerates anew in all its parts, and even in the smallest fragments, that may be grafted by aproximation or inoculation, turned inside outwards like a glove, afterward cut, turned back and cut again, without ceasing, to live, devour, grow, and multiply?

* Naturalists have been uniformly straightened in the attempt, to institute a positive criterion for the line of demarkation between animal and vegetable beings:

and equally so for that between vegetables and fossils. There is such an obvious gradation in the scale of beings, that it appears impossible to ascertain where one species ends, and the other begins. At first thought it would appear imposing, that the criterion of sensibility, and reflection was adequate to the object. But students in natural philosophy, have found themselves so bewildered by the infinite gradation of these characters, that they have been necessitated to resort to other modes of discrimination. In one instance it has been supposed as sufficiently dis­criminative, of fossils, vegetables, and animals, that fossils grow and increase; that vegetables grow and live, and that animals alone have sensation. Boerhaave at­tempted the discrimination by fructification, and a mouth And considered the vegetable world as properly distinguished by its blossoms and fruit, and the ani­mal, by the mouth. But here it has been objected, that as blossoms and fruit are mere appendages of growth, and maturity, and a mouth merely the instrument by which nourishment is conveyed to the body; they cannot be considered as an essen­tial distinction; because fossils are also subject to the different stages of growth, maturity, and decay. And vegetables also require nourishment, and are furnish­ed with instruments (or conveying it into their bodies; and where the end is the same, a difference in the means can never be essential. The fixing the difference in a gula, stomach, and intestines, as is done by Dr. Tyson, is as little to the pur­pose. Some naturalists have assumed locomotive powers, as an absolute criterion for discriminating between animals and vegetables; but lord Kames has confront­ed this position by several curious instances of the locomotive powers of plants, some of which he says would do honour to an animal. Indeed the instances of ap­parent sagacity and economy in vegetables are very numerous, and the almost total want of it in some animals is equally striking. The petals of virgin flowers are observed to expand in the sun, but contract at night, or on the approach of rain; but after the seeds are fecundated, they cease to contract. Some plants turn to the sun, others turn from it: many plants in the night vary the positions of their leaves, and this is styled the deep of plants. A hop plant twisted round a stock, directs its course from S. to W. as the sun does; untwist it, and tie it in the oppo­site direction, it dies. Leave it loose in the opposite direction; it recovers its na­tural direction in a single night. The root of a tree meeting with a ditch, is laid open to the air: it alters its course like a rational being; dips into the ground: surrounds the ditch: rises on the opposite side, to its wonted distance from the surface, and then proceeds in its wonted direction. By comparing the above and other instances of seeming voluntary motion in plants, with that share of life, wherewith some of the inferior kinds of animals are endued, and putting sensation out of the question, we should scarcely hesitate at ascribing superiority to the for­mer. The sensitive plant, the hop, and the honeysuckle, would claim precedence to many species of beings, which we rank as animals. Some muscles for instance are fixed to one place as much as plants are, nor have they any power of motion except that of merely opening and shutting their shells: and in this respect, they have no superiority over the sensitive plant. Nor doth their motion discover more sagacity, nor even so much as the roots of the plane tree mentioned by lord Kames, which directed its roots ten feet down a wall, to come at a greater supply of nourishment. But there are instances wherein nature appears to combine the animal and vegetable functions, in the same beings, and thc polypus may be con­sidered as the intermediate lint between the two kingdoms.

It was not a fit season, therefore, to make general rules, to arrange nature, establish distributions, form systematical orders, and to raise an edifice, which future ages, better instructed, will even dread to project. We have scarce any knowledge of the animal when we would undertake to define it. Because our knowledge is at present is some measure improved, shall we presume to think we thoroughly know it. Polypuses have astonished us, because on their first appearance there was no idea in our brain analogous to them, and we had taken great pains to discard from it the very possibility of their existence. How many animals are there that are even more strange than polypuses, and that would confound all our reasoning, could we discover them! It would be necessary on that occasion to invent a new language, in order to describe our observations. Polypuses are placed on the frontiers of another universe, that will one time or other have its Columbuses and Vesputiuses. Shall we imagine that we have penetrated into the interior parts of the continents, because we have taken a slight view of some coasts at a distance? We will form to our­selves more exalted ideas of nature ; we will consider her as one im­mense whole, and will firmly persuade ourselves that what we disco­ver of her, is but the smallest part of what she contains. Having been heretofore astonished, we will forbear being so for the time to come, but will continue our observations; we will amass fresh truths, connect them if we are able, and be in expectation of every discovery, because we will continually say, that the known cannot serve as a mo­del for the unknown, and that models have been varied ad infinitum. Cluster-polypuses multiply by dividing themselves; who can tell but that there may one time or other be discovered animals, that instead of dividing themselves, may unite together, and join themselves to one another, in order to compose one single animal? Or who knows whether the multiplication of such an animal may not have as an essen­tial condition, the consolidation of several animalcules in a single one? We say that an animal must have a brain, a heart, arteries, veins. nerves, a stomach, &c. These are the ideas we have deduced from large animals, and we carry them every where with confidence. We act herein like a French traveller, who should expect to find in the Ter­ra Australes the mode of his own country, and that would be greatly cha­grined on being disappointed. The animal kingdom has also its Terra Australes in which probably it is not customary to meet with a brain, a heart, a stomach &c. Why do we desire that nature should always condescend to form one animal with the elements of another? She might indeed be constrained so to do, did not her fecundity surpass that of our poor conceptions! But the Hand, which has formed the poly­pus. has demonstrated to us, that it can, when necessity requires animalize matter at a much less expense. It has descended by almost insensible degrees from those great organized masses we call quadrapeds, to those minute organized bodies we style insects; and by gradual and skilfully contrived subtractions, it has at length reduced animality to her smallest terms. We are unacquainted with these smallest terms. The polypus, simple as it appears to be, is without doubt, very much compounded, in comparison of such animals as are placed be­neath it in the scale. It is, if we may be allowed the expression, too’ much an animal to be the last term of animality. We know that the brain is the principle of the nerves, that it filters the spirits; that the nerves are the organ of feeling; that the heart is the primum mobile of circulation ; that the veins and arteries are the dependencies; all this we have seen in great animals, we have again to our surprise found it in insects: though under different forms; we were thus accustomed to regard these various organs, and some others, as essential to the animal. The polypus, however exhibits to us nothing similar; the best micro­scopes only discover to us an infinite number of small disseminated seeds in its whole substance; and the unforeseen experiment of its shifting, sufficiently proves that there is nothing in its structure com­mon to that of animals-before known to us. Were we not capable of imagining, that an animal had been endued with the property of being propagated and grafted like a plant, it would have been much less possi­ble for us to suspect that there had been granted to it the power of being turned inside out like a glove. The arm-polypus, is neverthe­less a perfect animal; its voracity is excessive; it devours all the little insects that happen to touch it, and seizes them with such skill, as seems to give it an affinity to hunting animals. The cluster-polypus, quite differently constructed, has not the same advantages, but has relative ones ; it can excite a rapid motion in the water, which bring towards it those living corpuscles it feeds upon. There are undoubt­edly many animals that are still much more disguised than the cluster ­polypus, and by not affording us any exterior sign of animality, leave us for a long time uncertain of their true nature. When a bulb of such a polypus is detached from it, and fixes it by its short pedicle to any support, should we be apt to consider it as an animal production has not the gall insect been taken for a real vegetable gall-nut by such observers as had not seen it in its primitive’ state? Is not the pond muscle deficient in many things we judge to be necessary for the ani­mal? How many shell fish are still farther degraded ? Nay more, there may probably exist some animals which it would be impossible for us to acknowledge as such, even though their whole structure, as well internal as external, should be laid open to us; the reason is, that judging only according to our present notions, we cannot deduce from this structure the opinion of life.

15.  I cannot yet quit this subject. We are notable to conceive the methods by which the author of nature has given life and sensation to a prodigious number of different beings. Let us judge of at least by a comparison of a small number of animated beings we are acquainted with. How greatly does life differ in the ape and bell. poly pus? What intermediate degrees are there betwixt those terms ? Perhaps there are still more from this polypus to the last us animals. I do not examine if souls have been varied like bodies; but I conceive that organized matter has been modified infinite to which have corresponded as many different methods of Participating life and sensation. I likewise conceive that the same soul, if placed successively in all the organized bodies that exist, would Successively experience all the possible modifications of life and sensibility. This soul would pass through all the degrees of animality; and if she could remember them all, and compare them, she would equal the superior intelligences in knowledge. She would contemplate our world through all those glasses that have been given to the various beings that inha­bit it.

16.  Let us draw a general consequence from all this: that analogy which is one of the great lights of physic, is not capable of dissipating the shades of it. This light is frequently extinguished on the approach of certain bodies which we bring to the touch of experiment. To what purpose does analogy serve in the examination of the bulb-poly­pus? We cannot even define these bulbs; and does the name we give them express any thing more than mere appearances? How can analogy enlighten us concerning the nature of these minute bodies, and the manner by which they are engendered and engender, whilst she offers nothing to us either in the vegetable or animal kingdom, which bears the least relation to these productions, so different from all those that were known to us? I affirm as much with regard to the natural division of the bells, and of the shifting of the arm-polypuses. This is an entire new order of things, which has its particular laws, which we should in all probability be able to discover, could we find some means of penetrating into the secret mechanism of these little beings. We should then discern all the sides by which they are con­nected with other parts of the organical world.

17.  When we consider in a general view the composition of men and quadrupeds, we shall presently discern that there is with respect to all of them the same foundation of structure, differently modified in different species. In order to be convinced of this, we need only cast our eyes on those anatomical plates, in which are represented the skele­tons of divers animals that have been dissected. From man, the ape, and horse, to the squirrel, weasel, and mouse, we shall see throughout the same design the same arrangement the same essential relations, except in a few particulars. The spine which is formed of a series of parts, joined to each other as by so many hinges, bears to its upper extre­mity a sort of bony box, of greater or less extent. Some bony arches, which on one side are connected with the spine, and on the other with  part opposite to it, form another more spacious box. The upper and lower extremities are joined likewise to the spine by different inter­posed bands, and maintain the body in those various attitudes its exigencies require. This economy is so generally observed, that it has even been remarked that the vertebrae of the neck are seven in number in all the species. Almost the same order is to be met with in birds and fishes:

It varies more and more in reptiles, shell-fish, and insects. The latter however have their bones, several parts of which seem to imi­tate the corresponding ones in great animals; but whereas among the latter the flesh covers the bones; on the contrary, among insects the bone covers the flesh. In this numerous class of little animals, nature has in an especial manner diversified her models the most, and displayed the wonderful fecundity of her inventions. In the large parts of the animal kingdom, she pretty nearly pursues the same plan of architec­ture, and hardly diversifies any thing but the orders. In one we behold the strength and majesty of the Tuscan; in others the elegance and delicacy of the Corinthian. But when she descends to insects, she seems entirely to change her plan, and to retain as little as possible of her first models. She seems at length to abandon them altogether in her formation of an arm or bell-polypus, She constructs plants on still different models: but these models retain in them something of the organization of animals, and particularly that of insects. The organs of respiration are almost the same in the plant and insect. Those parts which are essential to life, are dispersed throughout the whole body of the plant, as they are in insects that are reproduced by slips. Those plants which appear to be most elevated in the scale, exhibit to us a stalk, branches, roots, leaves, flowers, and fruit. A swine-bread, an agaric, a liverwort, on the contrary, are so extremely disguised, and have in them so small a resemblance to plants3 that it is necessary to have the eye of a strict observer, in order to know and characterize them. These half vegetable productions, if I may be allowed the phrase, seem in the vegetable kingdom, to be what the gall-insect, poly pus, and the muscles, are in the animal. They do not appear to be more organized than an amianthus, a talc, or a crystal.

18. The distance however is much greater from the most regular fossil, or that most resembling a vegetable, to the plant in the least degree so, or that is the least organized. The fossil does not grow, properly speaking: it does not receive nourishment, nor engender. It is formed of the successive apposition of different molecules, which by uniting together under certain relations, determine its figure. The plant is a body truly organized, which of itself works the molecules, destined to incorporate themselves with its substance, and to extend it every way; and contains little bodies resembling it, which it nourishes causes to expand themselves, and by means of which it multiplies its being. Nature then seems to make a great chasm in passing from the vegetable to the fossil, &c. There are no bands, no links hitherto known to us, which unite the vegetable to the mineral kingdom. But shall we form our judgment of the chain of beings by our present degrees of knowledge? Because we here and there discover in it some ruptions, some void spaces, shall we conclude from thence that they are real? Shall we imagine that a comet has split the scale of world, and destroyed the harmony of it? We are only beginning to survey the vast cabinets of nature ; and amongst that innumerable multitude of various productions which she has assembled, how many are there which we have not so much as seen, and can frame no idea of their existence? Shall we hasten to decide concerning the result of these productions, before we have examined them all, or formed exact list of them? The vacancy we suppose left between the vege­table and mineral, will in all probability be one day supplied. There was a similar void betwixt the animal and vegetable: the polypus now fills it up, and sets in a conspicuous light the admirable gradation there is among all beings. It is true we cannot form any mean idea betwixt.. the plant and the fossil; we do not imagine there is any shadowing between growth and apposition: but had we formed any conception of the properties of the polypus? If those marine productions, which have been called stony plants, were real plants, they were in some measure one of the links requisite for uniting the vegetable to the mineral kingdom. But late discoveries have informed us, that these pretended plants are only works of certain polypuses, that have the art of constructing cases for themselves. Those coral flowers, so muck celebrated, were real polypuses; and this is another truth wherewith the polypus has enriched the physical world.

19.  Organized bodies are tissues which are more or less fine pieces if net work, or pieces of stuff, whose warp itself forms the woof, by an art which we should think we could never enough admire, were we acquainted with it. Fossils are a kind of inlaid work. We do not know where the organization ends, nor which is its smallest term. But by ceasing to organize, nature does not cease to dispose or arrange. She even seems to organize when she has made an end of doing so. One would be ready to imagine that fibrous and leaved stones were vegetables in part disguised. The constant regularity of salts and crystals strikes us in an equal degree. We may be assured, that the crystal is formed of the repetition of an infinite number of small, regular and pyramidial bodies, properly laid on each other, which represent, in some measure, the whole exactly in miniature. We should notwithstanding, be very much mistaken, were we to consider these little pyramids as the germ of the crystal; it is strictly speaking no more than an element or constituent particle of it. It does not unfold itself, it remains as it was; but it serves as a support to other similar pyramids which are to be joined to it, and thus to augment the crys­taline mass by successive aggregates. The crystaline juice is not received wrought, and assimilated by strainers or vessels that are more or less fine, or more or less folded together, within the pyramid ; it is already entirely prepared when it procures the union of different molecules into one pyramidal mass, by virtue of the laws of motion and attraction. This is the primary character which distinguishes brute from organized bodies: a character which we ought never to lose sight of, when we compare together beings of these two classes.

20. Thus the bodies of plants and animals are species of looms, machines more or less compounded, which convert into the proper substance of the plant or animal, the various matters subjected to the action of their springs and liquors. These machines, which are; so superior in structure to those of art, seem still more so when com­pared in their essential effects. Those matters which organical ma­chines work, they likewise assimulate and incorporate with themselves; they grow by this incorporation, augment in their dimensions every way, and during their growth, all their parts preserve among them­selves the same relations, the same proportions, the same exercise; all continue to discharge their proper functions: the machine remains in its extended state, what it was in miniature. It is a system, a won­derful assemblage of an almost infinite number of tubes, differently formed, calibered, and interwoven, that like so many filters, purge, fashion, and refine the nutricious matters. Each fibre; what am I say­ing! Each fibrilla is itself a machine in miniature, which by perform­ing analogous preparations, appropriates to itself the alimentary juices. and gives them the arrangement suitable to its form and their func­tions. The whole machine is in some measure only the repetition of all these lesser machines, whose united strength conspires to the same general end. The excellence of organical machines appears in a conspicuous light from other still more striking instances. They not only produce, from their own foundation, machines simi­lar to them, but a great number of them reproduce of themselves, those parts they had been deprived of, which various parts become afterward as many machines, equally perfect with those whereof they before only made a part.

21.  To conclude: the same general design comprises all parts of the terrestrial creation. A globule of light, a molecule of earth, a grain of salt, a particle of mouldiness, a polypus, a shell fish, a bird, and a quadruped, man, are only different strokes of this design : and represent all possible modifications of the matter of our globe. My expression falls greatly beneath reality; these various productions are not different strokes of the same design they are only so many various points of a single stroke, that by its infinitely varied circumvolutions, traces out to the astonished eyes of the cherubim, the forms, proportions, and concatenation of all earthly beings. This single stroke delineates all worlds, the cherub himself is a point of it: and that adorable Hand which drew this stroke, alone posseses the method of describing it.