CHAPTER I.

A COMPARISON BETWEEN ANIMALS, VEGETABLES, AND OTHER PRODUCTIONS OF NATURE.

Amidst the infinite number of objects that offer themselves to our view, and with which the surface of the earth is every where covered, Animals hold the first rank both on account of their formation, and their evident superiority over vegetables and other matters. Animals, by their senses, form, motion, and many other properties, have a more intimate connection with those things which surround them than vegetables; and the latter, by their figure, growth, and variety of component parts, have also a nearer relation with external objects, than either minerals or stones, which have not any kind of life or motion. By this number of properties it is, that the animal claims pre-eminence over the vegetable, and the vegetable over the mineral. Man, to consider him by his material form alone, is only superior to the brute creation by possessing some few peculiar properties, such as those given to him by his tongue and hands; and although the works of the Creator are in themselves equally perfect, the animal, according to our mode of perception, is the most complete, and man the most perfect animal.

What variety of springs, what forces, and what mechanical motions are enclosed in this small part of matter which composes the body of an animal? What properties, what harmony, and what correspondence between the various parts? How many combinations, arrangements, causes, effects, and principles, conspire to complete one end, and which we know only to be results so very difficult to comprehend, that they only cease from being marvellous by the long custom of not reflecting on them?

Nevertheless, however admirable this work appears, it is not the individual that is the most wonderful; but it is in the succession, reproduction, and duration of species, that nature becomes inconceivable. This faculty of reproduction, which resides alone in animals and vegetables; this kind of unity always subsisting, and seemingly eternal; this procreative power, which perpetually exercises itself without being destroyed, is a mystery, the depth of which we are not enabled to fathom.

Inanimate bodies, even the stones and dirt under our feet, have some properties; their existence alone supposes a great number; and the least organic matter has an infinity of relations with the other parts of the universe. We shall not say, with some philosophers, that matter, under whatever form it may be, is sensible of its existence and relative faculties. This is a metaphysical question, and of which we do not here propose to treat, it will be sufficient to observe, that not having a perfect knowledge of our own relation with external objects, we cannot doubt that inanimate matters are still more ignorant; besides, as our sensations do not in the least resemble the objects which cause them, we must conclude, by analogy, that inanimate matter has neither sentiment, sensation, nor a consciousness of its existence; to attribute any of these faculties to it, would be giving it the power of thought, action, and perception, nearly in the same manner as we think, act, and feel, which is as much repugnant to reason as it is to religion.

Inanimate bodies being formed of earth and dust, we have, of course, some properties in common with them, but they are merely relative to what arises from general matter, such as extent, impenetrability, weight, &c. but as these properties, purely material, make no impression of themselves, as they exist entirely independent, and do not at all affect us, we cannot consider them as a part of our being; it is therefore the organization, the soul, and the life, which constitute our existence. Matter, considered in this light, is less the principal than the accessor. It is a foreign expansion, the union of which is unknown, and the presence hurtful to us; and thought, which is the constituent principle of our being, is very probably entirely independent.

We exist, therefore, without knowing how, and we think without knowing why; but whatever is the manner of our being or thinking, whether our sensations are true or false, the result of them are not less certain. This order of ideas, this train of thoughts, which internally exist from ourselves, although very different from the objects that cause them, give rise to the most real affections, and occasion relations with external objects, which we may consider as real affinities, since they are invariable, and always the same. The human species, therefore, may be said to hold the first rank in the order of nature, the brute creation the second, vegetables the third, and minerals the last; for although we cannot clearly distinguish between our animal and spiritual qualities, and although the brute creation are endowed with the same senses, possess the same principles of life and motion, and perform a number of actions like man, yet they have not the relation with external objects in the same extensive manner we have, and consequently the resemblance must fail in various respects. The distance is greater between man and vegetables, and still more so from minerals, as vegetables possess a degree of animation, while minerals are destitute of every principle that tends to organization.

To compose, therefore, the history of an animal, we must first nicely inspect into the general order of his particular relations, and afterwards distinguish those he has in common with vegetables and minerals. An animal has nothing in common with a mineral, excepting general properties of matter; his nature and oeconomy are totally different: the mineral is a mere senseless and inactive matter, without organization, faculties, or power of reproduction; a dead mass, fit only to be trod under foot by man and animals; even the most precious metals are thus considered by the philosopher, as they possess but an arbitrary value, subordinate to the will, and dependent on the convention of men.

In an animal all the powers of nature are united; the properties by which it is animated are peculiar to it; by its senses it can will, act, determine, and communicate with the most distant objects: its body is a centre, to which every thing is connected; a point where the whole universe is reflected; a world in miniature. These are the properties which peculiarly belong to it; those which it possesses in common with vegetables are the faculties of growth, expansion, reproduction, and increase.

The most apparent difference between animals and vegetables seems to be the faculty of moving from place to place, which animals are endowed with and vegetables not. It is true we are not acquainted with any vegetable that has a single progressive motion; and there are many kinds of animals, as oysters, &c. to which this motion seems to have been denied; the distinction, therefore, is neither general nor necessary.

A more essential difference might be drawn from the faculty of sensation; but sensation includes such a variety of ideas, that we ought not to mention the word without giving some explication; for if by sensation we understand only a motion, occasioned by a check or resistance, we shall find the _sensitive_-plant is also possessed of it; if, on the contrary, we would have it signify to apprehend and compare ideas, we are not certain that brute animals possess it; if it is allowed to dogs, elephants, &c. whose actions seem to result from the same causes as those of men, it must be denied to an infinite number of others, especially to those which seem to be motionless. If we could give to oysters, for example, the same faculty of sensation as to dogs, though in an inferior degree, why should we not allow it to vegetables in a still lesser degree? This difference between animals and vegetables is not, therefore, general, nor well decided.

A third difference seems to arise from their method of feeding. Animals, by the means of certain external organs, seize those things which are agreeable to them: they seek their pasture and chuse their food. Plants are reduced to the necessity of receiving such nutriment as the earth furnishes: they have no diversity in the manner of procuring it; no choice in the kind, but the humidity of the earth is their only aliment; nevertheless, if we attend to the organization and action of roots and leaves, we shall presently discover that there are in those parts external organs, which vegetables make use of to obtain their food; that the root avoids and turns from an obstacle, or vein of bad earth, to seek for one that is better; that they divide their fibres, and even go so far as to change their form to procure nutriment for the plant. The difference between animals and vegetables cannot, therefore, be established on the manner in which they receive their nutriment.

This investigation induces us to conclude that there is no absolute essential and general difference between animals and vegetables, but that nature descends, by degrees imperceptibly from an animal which is the most perfect, to that which is the least, and from the latter to the vegetable. The water polypus may therefore be considered as the line where the animal creation ends and that of plants begin.

If, after having examined the distinctions, we search after the resemblances between animals and vegetables, we shall find the power of reproduction is general, and very essential to both; a faculty which would almost lead us to suppose that animals and vegetables are nearly of the same order of beings.

A second resemblance may be drawn from the expansion of their parts, a property which is common to both; for vegetables grow as well as animals, and if the manner in which they expand is different, it is not totally nor essentially so, since there are very considerable parts in animals, as the bones, the hair, the nails, the horns, &c. whose expansion is a perfect and real vegetation; and the foetus, at its first formation, may be said rather to vegetate than live.

A third resemblance arises from there being some animals which propagate like plants, and by the same method. The multiplication of the vine-fretter, which is made without copulation, is like that of plants by seeds; and that of polypuses, by cutting them, resembles the multiplication of trees by slips.

We can then assert with greater foundation, that animals and vegetables are beings of the same order, and that nature passes from one to the other by insensible links; since the properties wherein they resemble each other are general and essential, and those on which they differ confined and particular.

If we compare animals and vegetables by other lights, for example, by number, situation, size, form, &c. we shall draw fresh inductions from them.

The number of the animal species is much greater than that of plants. In the class of insects alone there are a greater number of species than there are kinds of plants on the surface of the earth. Animals likewise much less resemble each other than plants; and it is this resemblance among the latter which makes the difficulty of knowing and discerning them, and has given rise to so many botanical systems; and it is for this reason that more labour has been bestowed on that than on zoology.

Besides, there is another advantage of knowing the species of animals, and distinguishing them one from another, which is by regarding those as one and the same species, who, by means of copulation, produce and perpetuate beings like themselves; and as a different species, those from a connection between whom nothing is produced, or whose product are unlike their parents. Thus a fox will be a different species from a dog, if nothing results from a copulation of a male and female of these two animals, and when even there should result a bipartite animal, or a kind of mule, which cannot generate, that will be sufficient to establish the fox and dog of two different species. There is not the same advantage to be had in plants, for although some have pretended to discover sexes, and although divisions of breeds have been established by the parts of fecundation; yet, as these distinctions neither are so certain, nor so apparent as in animals, and the production of plants is made in many modes, that the sex has no part in, and where the parts of fecundation are not necessary, this idea cannot be made use of with any success; it is only on a misapprehended analogy that this sexual method has been pretended to distinguish all the different species of plants.

Notwithstanding the number of animals is greater than that of plants, yet that is not the case with respect to the number of individuals in each species. In animals as well as in plants, the number of individuals is much greater in the small species than in the large. Flies are, perhaps, a million times more numerous than elephants; so likewise there are more kinds of plants than trees; but, if we compare the quantity of individuals in each species, we shall find that the plant is more abundant than the animal; for example, quadrupeds bring forth but a small number of young, and at considerable distances of time; trees, on the contrary, produce every year, a great quantity. It may be said that this comparison is not exact, and to render it so, we should compare the quantity of seeds produced by a tree, with a quantity of germs contained in the semen of an animal, and then, perhaps, we should find, that animals are still more abundant in their seed than vegetables. But it should be considered that it is possible by collecting and sowing all the seeds of an elm, for instance, that we might have 100,000 young ones from the product of a single year; and that should we supply a horse with as many mares as he could cover in one year, there would be a great difference between the production of the animal and that of the vegetable. I shall not examine into the quantity of germs; first, because we are not acquainted with it in the animal creation: and secondly, because possibly there is the same number of seminal shoots in the vegetable: for the seed of a vegetable is not a germ, being as perfect a production as the foetus of an animal, and to which, like that, a greater expansion is only wanting.

To my comparison may likewise be opposed the prodigious multiplication of certain kinds of insects: as the bee in particular, one of which will produce thirty or forty thousand. But it must be observed, that I speak in general of animals compared with vegetables; and besides, this example of bees, which perhaps is the greatest multiplication among animals, does not constitute a proof against what we have observed; for of thirty or forty thousand flies produced by the female bee, there is but few females; fifteen hundred, or two thousand males, and all the rest moles, or rather neutral flies, without sex, and incapable of procreating.

It must be owned, that in insects, fish, and shell-fish, there are species which seem to be very abundant; oysters, herrings, fleas, beetles, &c. are perhaps in as great numbers as mosses and the most common plants; but on the whole, the greatest number of the animal species is less abundant than the vegetable; and by comparing different kinds of plants with each other, there is not found such great differences in the number, as in the animal species; some of which bring forth a prodigious number, and others only a few; whereas the number of productions in plants is always very great throughout.

By what we have observed, it appears that the smallest and basest species seem to be the most prolific: the most minute are the most plentiful as well in animals as in plants, and in proportion as the animals are more perfect, they appear to decrease in number of individuals. Can it be thought, that certain forms of the body, as those of quadrupeds and birds, requisite for the perfection of sensation, would cost nature more organic particles than the production of less important animals?

Let us now pass to the comparison of animals and vegetables, with respect to situation, form, and size. The earth is the only place wherein vegetables can subsist. The greatest number grow above the surface, and are attached to the soil by roots. Some, as truffles, are entirely covered with earth, and a few grow under the water, but all require the surface of the earth to exist upon. Animals, on the contrary, are more generally dispersed; some dwell on the surface, and others in the bowels of the earth; some live at the bottom, and others swim in the waters of the ocean: some exist in the air, others dwell in the internal parts of plants, on the bodies of men and other animals, liquors, and even stones are not without them.

By the use of the microscope, a great number of new species of animals have been discovered: but singular as it may appear, we have not found more than one or two new species of plants by the help of this instrument. The small moss is, perhaps, the only microscopical plant spoken of; and we might, therefore, imagine that nature refused to produce very small plants, while she formed animalcules with profusion; but we might deceive ourselves by adopting this opinion without examination, and our error might arise from plants, in fact, resembling each other more than animals; so that this moldiness, which we only take for a very minute moss, may possibly be a kind of forest or garden, filled with abundance of various plants, although we are unable to mark the difference.

By comparing the size of animals and plants there will be found a great inequality, for the distance is much greater between the size of a whale and one of these microscope animals, than between the highest oak and the moss we are now speaking of. Although bulk be only a relative attribute, it may, nevertheless, be useful to inspect into the extreme boundaries nature has allotted to her productions. In bigness animals and plants seem to have a near equality; a large whale and a large tree forms a volume not very different; whereas, among the small it has been asserted there are animals so very minute that a million of them united together, would not equal, in size, the smallest moss-plant ever seen.

The most general and most sensible difference between animals and vegetables is that of figure, for the form of animals, although infinitely varied, has not any resemblance to that of plants; and although the polypus will, like plants, reproduce by cutting, and may be regarded as the link between the animal and vegetable kingdoms, not only by the mode of their reproduction but also by their external form, nevertheless the figure of the animal is so different from the external form of a plant that it is difficult to be deceived therein. Some animals form things resembling plants or flowers, but plants never produce any thing like an animal; and those admirable insects which produce and form the coral, would not have been taken for flowers if coral had not been regarded as a plant. Thus the errors wherein we might fall, by comparing plants with animals, will never have any influence but on a few objects which compose the link between both, and the more observations we shall make the more we shall be convinced that the Creator has not placed a fixed line between animals and vegetables; that these two species of organized beings have many more common properties than real differences; that the production of an animal does not require of nature more, and possibly, less exertion than that of a vegetable; that in general the production of organized beings does not require exertion, and that, in short, the living animated nature, instead of composing a metaphysical degree of beings, is a physical property, common to all matter.