and it remains also for me to offer examples from among the more curious or striking instances of each of these recondite powers, both under a more simple and a more complicated modification. This shall form the basis of our ensuing study. At present I shall only farther observe that instinct may be defined the operation of the principle of organized life by the exercise of certain natural powers directed to the present or future good of the individual; and reason the operation of the principle of intellectual life, by the exercise of certain acquired powers directed to the same end. Both equally answer their object, are equally perfect in their kind, and equally display their common origin.

Whether with Reason or with Instinct blest,

Thus all enjoy the power which suits them best;
To bliss alike by that direction tend,

And find the means proportion'd to their end.
Say, where full Instinct is th' unerring guide,
What Pope or Council can they need beside?
Reason, however able, cool at best,

Cares not for service, or but serves when press'd;
Stays till we call, and then not often near;
But honest Instinct comes a volunteer:
Sure never to o'ershoot, but just to hit,
While still too wide or short is human wit;
Sure, by quick nature, happiness to gain,
Which heavier Reason labours at in vain.
This, too, serves always, Reason never long,
One must go right, the other may go wrong;
See then the acting and comparing powers,
One in their nature, which are two in ours;
And Reason raise o'er Instinct as you can,
In this 't is God directs, in that 't is man.-POPE.

LECTURE V.

ON THE DISTINCTIVE CHARACTERS OF INSTINCT, SENSATION, AND INTELLIGENCE.

WE closed our last study by observing that instinct is the operation of the principle of organized life by the exercise of certain natural powers directed to the present or future good of the individual, while reason is the operation of the principle of intellectual life by the exercise of certain acquired powers directed to the same end. Hence reason demands discipline and attains maturity; instinct, on the contrary, neither demands the one nor is capable of attaining the other; it is disciplined and mature from the first, and is as perfect in the infant as in the man.

Instinct, however, has as often been confounded with FEELING OF SENSATION as it has with PERCEPTION, which is the outline or foundation of reason: and hence another source of those perplexities and errors in distinguishing between animal and vegetable life which we noticed in the preceding lecture: perplexities and errors which have been productive of the most absurd and disgusting consequences, and especially in regard to the delicate and elegant science of botany.

Instinct, sensation, and perception are all principles essentially different; they may, indeed, exist conjointly, but each of them is capable of existing separately. Instinct is the common law or property of organized matter, as gravitation is of unorganized; and the former bears the same analogy to sensation and perception as the latter does to crystallization and chemical affinity. Instinct is the general faculty of the organized mass, as gravitation is of the unorganized mass; sensation and perception are peculiar powers or faculties appertaining to the first, as crystallization and affinity are apper taining to the second: they can only exist under certain circumstances of the organized or unorganized matter to which they respectively belong.

This parallel, indeed, may be carried much farther. Gravitation discovers itself under different modifications, different degrees of power, and, conse

quently, different effects. Instinct evinces an equal diversity in all these instances. Gravitation belongs equally to the smallest and to the largest portions of unorganized matter: instinct, in like manner, belongs equally to the smallest and to the largest portions of organized matter; it exists alike in solids and in fluids; in the whole frame and in every part of the frame; in every organ, and in every part of every organ, so long as the principle of life continues. Sir Isaac Newton established the doctrine of gravitation, and overcame all objections to it chiefly by the modesty with which he propounded and illustrated it. Without inquiring into the nature of its essence, he con-tented himself with recognising it by its operations and laws. It is the aim of the present study to follow this great example; and leaving all discussions concerning the essence of instinct or of organized life, on which instinct is dependent, and which constitutes its sphere, as matter constitutes the sphere of gravitation, to point out nothing more than the nature of its action, and occasionally to catch a glance at the laws by which it is regulated.

From what has been already said, we see clearly that the power of instinct runs equally through the limits of vegetable and animal life, and consequently, that instinct, sensation and perception, whatever they consist in, are powers or principles essentially different. Instinct is the common property of organized life in all its forms, but life itself is not necessarily connected either with reason or sensation; and it is of no small consequence that we attend to this curious and extraordinary fact, the proofs of which are abundantly in our own possession. The blood is alive, and has all the common properties of life, as was very satisfactorily shown in an antecedent lecture, from the experiments of Mr. John Hunter; but we all know that it possesses neither feeling nor intelligence: the bones, the cartilages, the cellular membrane, and the cuticle are alive; but, in a state of health, they are equally destitute of both these properties, and whether in health or disease, are always destitute of the latter.

Sensation and perception, so far as we are capable of witnessing, can only exist in appropriate organs, as nerves, or modifications of nerves, which are the only known seat of the one, and the brain, or some modification of brain, which is the only known seat of the other. In the higher classes of animals, as mammals, birds, amphibials, and fishes, the nerves take their rise from the brain, or rather from some particular part of it. But this is not an indispensable law of life; for, in insects, we meet with nerves, but no brain; and in most zoophytic and many other tribes of worms, with neither brain nor nerves. And hence, wherever these organs or either of them are discoverable, it is consistent with right reason to infer, that the faculty also exists to which they respectively give rise. But, on the contrary, where neither of these organs exists, as in plants, and a multitude of the lowest tribes of animals, which in the zoological system of Lamarck are on this account denominated apathic or insentient,* we have the same reason for inferring that, though life is present, and, indeed, in many instances, peculiarly tenacious and vigorous, there is neither intelligence nor sensation; and that the whole of the vital functions and operations are performed, like the semblances of intelligence in the preceding case, by the common law of instinct; which, operating in different ways, in different organs, and beings of different structures, appertains to living matter of every kind.

These observations will apply to the vegetable as well as to the animal kingdom; for plants have a close analogy to the senseless tribes, the tubipores, madrepores, sponges, and infusory worms, we are now contemplating in their structure and origin, as well as in the limited range of their powers; these animals being in many instances equally simple in their make, and equally destitute of locomotion, and equally propagating their kinds by the generation of buds or bulbs, instead of by that of seeds or eggs. Like these low kinds of animals, plants, moreover, are altogether without organs either of sense or intelligence; and it is consequently correct to infer, that they are

Philosophie Zoologique.

equally without the faculties which it is the sole property of such organs to develope. And hence, again, however curious and astonishing the powers they occasionally evince, they are powers that can only be resolved, as in the case of zoophytic worms, into the ever present and ever active law of instinct or organized life. We hear, indeed, at times, of the ascription of mental or corporeal passions to vegetables; of general feeling and ideas; of love and languishment, and desire and aversion. But all this is fancy, and proceeds from an erroneous and contracted view of the general nature of the law of instinct, and its extraordinary power of supplying the place of sense and reason, where these, or the organs in which they reside, are not present. We hear, in like manner, occasionally, of the brain, stomach, lungs, and nerves of vegetables; but all this is still more imaginary than the preceding; it is a mere fancy built upon a mere fancy: nobody has ever been capable of pointing out the probable or even possible seat of such organs, and they have only been idly conjectured because the faculties to which they give rise have been conjectured antecedently.

Is there, then, no such thing as instinctive feeling ?—a term in every one's mouth, and which every one, till he tries, supposes he comprehends? What but an instinctive feeling is the love of life, the dread of death, the economy of pairing, and the desire of progeny ?

Wherever feeling exists, these, in a certain sense, may unquestionably be called instinctive feelings; but it should be remembered that the expression is, in every instance, of a compound character, and involves two distinct ideas, which may exist either separately or conjointly: and we have the same reason for using the phrase instinctive intelligence as instinctive feeling: for we can only mean, or ought only to mean, instinct combined with intelligence, or instinct combined with feeling, according to the nature of the case before us.

Combinations of this kind, indeed, are not unfrequent; and I shall presently proceed to produce examples of them: but it becomes necessary to observe, in the present place, that all the operations we are now adverting to, and which are usually characterized as instinctive feelings, as self-preservation, attachment to life, resistance of destruction, reproduction of the whole or of separate parts of the system, and even the economy of pairing, though often united with feeling, and not unfrequently with intelligence as well, occur, nevertheless, in a multiplicity of instances in which we have either direct proofs, or the most cogent reasons for believing, that there is neither feeling nor intelligence whatever; and that every thing is the result of pure, unintelligent, insentient instinct.

I have just observed that the blood is alive: it has all the common properties of life; irritability, contractility, and a power of maintaining its natural scale of heat, whatever be the temperature of the atmosphere by which it is surrounded: and it is perpetually showing its attachment to life by the due and discretionary exercise of these properties with a view of preserving life. It equally resists every excess of cold or of heat that may be injurious to it, and hence sometimes raises the thermometer and sometimes depresses it: it contracts itself, like the muscular fibre, upon the application of an appropriate stimulus, and conveys the principle of life, and powerfully assists in applying that principle to parts in which the vital action is languid, or has altogether ceased. There is no part of the animal system that evinces in a more eminent degree the faculty of self-preservation, or self-production, of attachment to life, or of resistance to whatever is injurious, than the blood; and yet every one knows that this faculty is pure, unmixed instinct, equally destitute of feeling or intelligence: it is, as I have already defined instinct to be in every instance, a "simple operation of the principle of organized life by the exercise of certain natural powers directed to the present or future good of the individual."*

In the new-laid egg we have an equal proof of the same faculty of self

* Compare here Girtanner's Mémoires sur l'Irritabilité, considerée comme Principe de Vie dans la Nature organisée.-Journ. de Physique, 1790.

preservation, the same attachment to life, and resistance to destruction. For, like the blood of a healthy adult, the new-laid egg, the few and simple vessels of which are merely in a nascent and liquescent state, and which can scarcely be regarded otherwise than as a fluid, is capable equally of counteracting heat, cold, and putrefaction, and does forcibly counteract them for a considerable period longer than an egg that has been frozen or in any other way deprived of its vital and instinctive principle. It is this vital and instinctive principle that alone matures the egg, and shapes the matter of which it consists into distinct and specific lineaments, and calls forth the power which it does not yet possess, of sensation and perception. In what way these attributes are produced we know not; but we see them issuing from the matter of the egg alone, when aided by the additional and cherishing power of simple heat. And, provided it be properly regulated and applied, it is of no importance from what quarter such heat is derived; for we have already had occasion to observe, that the warmth of a sand-bath or of an oven will answer as effectually as that of the mother's sitting over it.

But let us not rest here: let us proceed to examples of the renewal or propagation of life, from parent stocks; to examples of the reproduction of the whole, or of separate parts of the system, in cases in which there is as obvious a destitution of sensation or intelligence; and where, as in the preceding instances, the whole must be the result of pure insentient instinct.

There is not a single organ in the animal frame but what is perpetually reproducing itself, alternately dying and renewing; so that the same man of to-day has not an individual particle belonging to him of that which constituted his corporeal frame ten, fifteen, or twenty years ago. And yet the whole of this important change, this entire reproduction of the material system, though occurring in sentient and even in intelligent organs, occurs at the same time without any kind of feeling or consciousness in the individual, or the organs that constitute the individual.

This very curious fact is still more obvious in the generation of new matter of every kind,-muscular, glandular, bony, and even nervous, upon the death of a considerable portion of an organ in consequence of external injury or other violenee. The nice and admirable law by which the dead substance is carried off, and its place supplied by the gradual reproduction of fresh matter of the very same nature and properties, I have already explained.* In the separation of the dead from the living parts, there is generally, though not always, some degree of pain, from the increased local action that takes place, and more especially from the tension given to the skin by the secretion of sound and healthy pus, in order to effect its bursting; but in the actual generation of the new material that is to fill up the cavity, and supply the place of what is lost, there is no pain or sensation whatever in a healthy process; while, as I have likewise already observed, the pointing of the abscess, like the pointing of the seeds of peas or beans, in what direction soever they are sown, will be uniformly towards the surface,† whatever be the obstacles that must be overcome in order to reach it.

The generation of life, then, no more necessarily demands or implies the existence of sensation, than attachment to life, or a self-preserving principle: it may be combined with it, but it may also exist separately or without it. Monro, indeed, has distinctly proved by experiment, that the limb of a frog can live and be nourished, and its wounds healed, without any nerve whatever, and, consequently, without any source or known possibility of sensation. Let us apply this reasoning, which I admit is thus far drawn from individual parts of the system alone, to a regeneration or reproduction of the entire system. The lungs or gills of an animal are precisely analogous to the leaves of a plant. All these, as I have already observed, are perpetually changing by a nicely balanced alternation of decay and reproduction. In animals and evergreen plants this change is so gradual as to elude all notice. In deciduous plants, on the contrary, it is sudden and obvious to every one; yet the same

instinctive power that produces the one change produces also the other; and as in the former case we have a perfect consciousness that the effect takes place without any sensation or intelligence, no man will be so extravagant as to maintain that there is any sensation or intelligence concerned in the latter. But the very same process that produces the leaves or shoots of plants produces also their buds; the vegetable vessels are the same; there is no new principle employed, but merely an adaptation of the one common principle of instinct or the law of simple life to the production of a different effect; for the very same eye may, by too much or too little pruning of the wood, be converted into a shoot or into a bud. The buds of plants, however, are their proper offspring; and in many cases as perfectly so as their seed. lings, or those reared from seeds. In other instances we find a progeny equally perfect produced by a separation of bulbs or roots, or by radicles shooting out from creeping joints, as in the strawberry. In all which it would be absurd, even if plants were possessed of a nervous system, which they are not, to contend that a sense of feeling was more exerted than in the reproduction of the separate organs of an animal, to support the common wear and tear of animal life.

Why, then, should it ever have been contended that such a kind of sensation is necessary in the formation of seeds, by the conjoint action of what have been denominated a male and female organization? The stimulus of moisture, of light, heat, and air, evolves equally the specific flower; and the ever-present and all-pervading law of Nature determines the different parts of the flower, or the different flowers themselves, to be of different characters: the farina is secreted from the anther, a part which is called the male organ; and as it drops upon the open tube of the pistil, which is denominated the female organ, it becomes a new stimulus, and excites to a new action. But neither stimulus nor action are necessarily sensation, nor the sources of sensation. The pistil, or rather the receptacle which lies at the bottom of the pistil, in consequence of this new excitation, evolves or produces a new material, which we call a seed; but during the formation and evolution of this seed, from first to last, there is no more necessity for supposing the existence of any thing like sensation, than during the antecedent stimulus of the light, and heat, and moisture, upon the parent stem by which the flower itself became evolved; or during the same stimulus upon the joints or bulbs of the plant by which an equally healthy and perfect progeny has, perhaps, been produced from these different organs.

I have already observed, that in the lowest class of animals we meet with instances of reproduction equally varied, and of the very same nature: sometimes by buds or bulbs, as in the case of the polype; sometimes by slips or lateral offsets, as in one or two species of the leech; and sometimes, and perhaps more generally, by seeds or ova. But as, in the tribes I now refer to, we meet with neither nerves or nervous system, and as the reproduction of living matter does not necessarily demand the existence of a nervous system, or of that corporeal feeling to which alone, so far as we are acquainted with nature, a nervous system is capable of giving birth; we have the strongest reason for supposing that the generation of progeny is, in these cases, as unaccompanied with passion or sensation as in the instance of plants.

I have dwelt the longer upon this subject, as being anxious to divest one of the most elegant and interesting branches of natural history of the grossness and indelicacy with which it has been incrusted by the language and opinions of many modern physiologists; and to open it as widely as possible to the study and pursuit of every one.

It must be obvious, I think, that instinct has no more necessary connexion with feeling or sensation than with intelligence; and that even the faculties of attachment to life, resistance to destruction, the economy of pairing, and the process of generation, though often combined with both sensation and intelligence, are not necessarily combined with either of them; that intelligence is not more discrepant from sensation than sensation is from instinct; that either may exist separately, and that all may exist fogether.