have no connexion whatever in their original | rest, would always live in day light. An aniThe action of rays of light upon the surfaces mal, which, though made for action, and deof animals, has no tendency to breed eyes in lighting in action, must have its strength r their heads. The sun might shine for ever paired by sleep, meets, by its constitution, the upon living bodies, without the smallest ap-returns of day and night. In the human spe proach towards producing the sense of sight. cies, for instance, were the bustle, the labour, On the other hand, also, the animal eye does the motion of life upheld by the constant prenot generate or emit light. sence of light, sleep could not be enjoyed withV. Throughout the universe there is a won-out being disturbed by noise, and without exderful proportioning of one thing to another. The size of animals, of the human anímal especially, when considered with respect to other animals, or to the plants which grow around him, is such, as a regard to his conveniency would have pointed out. A giant or a pigmy could not have milked goats, reaped corn, or mowed grass; we may add, could not have rode a horse, trained a vine, shorn a sheep, with the same bodily ease as we do, if at all. A pigmy would have been lost amongst rushes, or carried off by birds of prey.

It may be mentioned, likewise, that the model and the materials of the human body being what they are, a much greater bulk would have broken down by its own weight. The persons of men who much exceed the ordinary stature, betray this tendency.

VI. Again (and which includes a vast variety of particulars, and those of the greatest importance;) how close is the suitableness of the earth and sea to their several inhabitants; and of these inhabitants, to the places of their appointed residence!

Take the earth as it is; and consider the correspondency of the powers of its inhabitants with the properties and condition of the soil which they tread. Take the inhabitants as they are; and consider the substances which the earth yields for their use. They can scratch its surface; and its surface supplies all which they want. This is the length of their faculties and such is the constitution of the globe, and their own, that this is sufficient for all their occasions.

When we pass from the earth to the sea, from ,land to water, we pass through a great change: but an adequate change accompanies us, of animal forms and functions, of animal capacities and wants; so that correspondency remains. The earth in its nature is very different from the sea, and the sea from the earth: but one accords with its inhabitants, as exactly as the other.

pense of that time which the eagerness of private interest would not contentedly resign. It is happy therefore for this part of the creation, I mean that is conformable to the frame and wants of their constitution, that nature. by the very disposition of her elements has commanded, as it were, and imposed upon them, at moderate intervals, a general intermission of their toils. their occupations, and pursuits.

But it is not for man, either solely or principally, that night is made. Inferior but less perverted natures, taste its solace, and ex pect its return, with greater exactness and advantage than he does. I have often observed, and never observed but to admire, the satisfaction, no less than the regularity, with which the greatest part of the irrational world yield to this soft necessity, this grateful vicissitude; how comfortably the birds of the air, for example, address themselves to the repose of the evening; with what alertness they resume the activity of the day.

Nor does it disturb our argument to confess, that certain species of animals are in mo. tion during the night, and at rest in the day. With respect even to them, it is still true, that there is a change of condition in the animal, and an external change corresponding with it. There is still the relation, though inverted. The fact is, that the repose of other animals sets these at liberty, and invites them to their food or their sport.

If the relation of sleep to night, and, in some instances, its converse, be real, we cannot reflect without amazement upon the extent to which it carries us. Day and night are things close to us; the change applies immediately to our sensations; of all the phenomena of nature, it is the most obvious and the most familiar to our experience; but, in its cause, it belongs to the great motions which are passing in the heavens. Whilst the earth glides round her axle, she ministers to the alternate VII. The last relation of this kind which necessities of the animals dwelling upon her I shall mention, is that of sleep to night; and surface, at the same time that she obeys the it appears to me to be a relation which was ex-influence of those attractions which regulate pressly intended. Two points are manifest, the order of many thousand worlds. The refirst, that the animal frame requires sleep; se-lation therefore of sleep to night, is the relacondly, that night brings with it a silence, and tion of the inhabitants of the earth to the roa cessation of activity, which allows of sleep tation of their globe; probably it is more; it being taken without interruption, and without is a relation to the system of which that globe loss. Animal existence is made up of action is a part; and, still farther, to the congregaand slumber; nature has provided a season for tion of systems, of which theirs is only one. If each. An animal which stood not in need of this account be true, it connects the meanest

individual with the universe itself; a chicken | pressed upon the constitution of the animai roosting upon its perch, with the spheres re- For, first, what should induce the female bird volving in the firmament. to prepare a nest before she lays her eggs? It VIII. But if any one object to our repre- is in vain to suppose her to be possessed of the sentation, that the succession of day and night, faculty of reasoning: for no reasoning will or the rotation of the earth upon which it de-reach the case. The fulness or distention which pends, is not resolvable into central attraction, she might feel in a particular part of her bowe will refer him to that which certainly is, dy, from the growth and solidity of the egg to the change of the seasons. Now, the con- within her, could not possibly inform her, that stitution of animals, susceptible of torpor, bears she was about to produce something, which, a relation to winter, similar to that which sleep when produced, was to be preserved and taken bears to night. Against not only the cold, but care of. Prior to experience, there was no the want of food, which the approach of win-thing to lead to this inference, or to this suster induces, the Preserver of the world has picion. The analogy was all against it: for, provided in many animals by migration, in in every other instance, what issued from the many others by torpor. As one example out body, was cast out and rejected. of a thousand-the bat, if it did not sleep] through the winter, must have starved, as the moths and flying insects upon which it feeds disappear. But the transition from summer to winter carries us into the very midst of physical astronomy, that is to say, into the midst of those laws which govern the solar system at least, and probably all the heavenly bodies.

CHAPTER XVIII.

INSTINCTS.

But, secondly, let us suppose the egg to be produced into day; how should birds know that their eggs contain their young? There is nothing, either in the aspect or in the internal composition of an egg, which could lead even the most daring imagination to conjec. ture, that it was hereafter to turn out from under its shell, a living, perfect bird. The form of the egg bears not the rudiments of a resemblance to that of the bird. Inspecting its contents, we find still less reason, if possible, to look for the result which actually takes place. If we should go so far, as, from the appearance of order and distinction in the disposition of the liquid substances which we noticed in the egg, to guess that it might be designed for the abode and nutriment of an ani mal (which would be a very bold hypothesis,) we should expect a tadpole dabbling in the sline, much rather than a dry, winged, feathered creature; a compound of parts and properties impossible to be used in a state of confinement in the egg, and bearing no conceiv. able relation, either in quality or material, to any thing observed in it. From the white of An INSTINCT is a propensity prior to ex- an egg, would any one look for the feather of perience, and independent of instruction. We a goldfinch? or expect from a simple uniform contend, that it is by instinct that the sexes of mucilage, the most complicated of all machines, animals seek each other; that animals cherish the most diversified of all collections of subtheir offspring; that the young quadruped is stances? Nor would the process of incubation, directed to the teat of its dam; that birds build for some time at least, lead us to suspect the their nests, and brood with so much patience event. Who that saw red streaks, shooting in upon their eggs; that insects which do not sit the fine membrane which divides the white upon their eggs, deposit them in those parti- from the yolk, would suppose that these were cular situations, in which the young, when about to become bones and limbs? Who, that hatched, find their appropriate food; that espied two discouloured points first making it is instinct which carries the salmon and some other fish out of the sea into rivers, for the purpose of shedding their spawn in fresh

The order may not be very obvious, by which I place instincts next to relations. But I consider them as a species of relation. They contribute, along with the animal organization, to a joint effect, in which view they are related to that organization. In many cases, they refer from one animal to another animal; and, when this is the case, become strictly relations in a second point of view.

water.

their appearance in the cicatrix, would have had the courage to predict, that these points were to grow into the heart and head of a bird? It is difficult to strip the mind of its exWe may select out of this catalogue the in. perience. It is difficult to resuscitate surprise, cubation of eggs. I entertain no doubt, but when familiarity has once laid the sentiment that a couple of sparrows hatched in an oven, asleep. But could we forget all that we know, and kept separate from the rest of their spe- and which our sparrows never knew, about ovi cies, would proceed as other sparrows do, in parous generation; could we divest ourselves every office which related to the production of every information, but what we derived and preservation of their brood. Assuming from reasoning upon the appearance or quathis fact, the thing is inexplicable, upon any lity discovered in the objects presented to us: other hypothesis than that of an instinct, im- I am convinced that Harlequin coming out of

an egg upon the stage, is not more astonish-attentively observed the conformation of the ing to a child, than the hatching of a chicken nest in which she was nurtured: and had trea both would be, and ought to be, to a philoso-sured up her remarks for future imitation : pher.

But admit the sparrow by some means to know, that within that egg was concealed the principle of a future bird: from what chemist was she to learn, that warmth was necessary to bring it to maturity, or that the degree of warmth, imparted by the temperature of her own body, was the degree required?

which is not only extremely improbable, (for who, that sees a brood of callow birds in their nest, can believe that they are taking a plan of their habitation?) but leaves unaccounted for, one principal part of the difficulty," the preparation of the nest before the laying of the egg." This she could not gain from observation in her infancy.

To suppose, therefore, that the female bird It is remarkable also, that the hen sits upon acts in this process from a sagacity and reason eggs which she has laid without any communiof her own, is to suppose her to arrive at con- cation with the male; and which are thereclusions which there are no premises to justi- fore necessarily unfruitful. That secret she fy. If our sparrow, sitting upon her eggs, ex-is not let into. Yet if incubation had been a pect young sparrows to come out of them, she subject of instruction or of tradition, it should forms, I will venture to say, a wild and ex- seem that this distinction would have formed travagant expectation, in opposition to pre- part of the lesson: whereas the instinct of na sent appearances, and to probability. She must ture is calculated for a state of nature: the have penetrated into the order of nature, far-exception here alluded to, taking place, chiefly, ther than any faculties of ours will carry us: if not solely, amongst domesticated fowls, in and it hath been well observed, that this deep which nature is forced out of her course. sagacity, if it be sagacity, subsists in conjunc- There is another case of oviparous economy, tion with great stupidity, even in relation to which is still less likely to be the effect of edu the same subject. "A chemical operation," cation, than it is even in birds, namely, that says Addison,"could not be followed with of moths and butterflies, which deposit their greater art or diligence, than is seen in hatch-eggs in the precise substance, that of a cab. ing a chicken: yet is the process carried on bage for example, from which, not the butter. without the least glimmering of thought or fly herself, but the caterpillar which is to issue common sense. The hen will mistake a piece from her egg, draws its appropriate food. The of chalk for an egg; is insensible of the in- butterfly cannot taste the cabbage. Cabbage crease or diminution of their number; does is no food for her: yet in the cabbage, not by not distinguish between her own and those chance, but studiously and electively, she lays of another species; is frightened when her her eggs. There are, amongst many other supposititious breed of ducklings take the wa-kinds, the willow-caterpillar and the cabbage

ter.

caterpillar but we never find upon a willow, the caterpillar which eats the cabbage ; nor the converse. This choice, as appears to me, cannot in the butterfly proceed from instruction. She had no teacher in her caterpillar state. She never knew her parent. I do not see, therefore, how knowledge acquired by expe

But it will be said, that what reason could not do for the bird, observation, or instruction, or tradition, might. Now if it be true, that a couple of sparrows, brought up from the first in a state of separation from all other birds, would build their nest, and brood upon their eggs, then there is an end of this solution.rience, if it ever were such, could be transmitWhat can be the traditionary knowledge of a chicken hatched in an oven?

Of young birds taken in their nests, a few species breed, when kept in cages; and they which do so, build their nests nearly in the same manner as in the wild state, and sit upon their eggs. This is sufficient to prove an instinct, without having recourse to experiments upon birds hatched by artificial heat, and deprived, from their birth, of all communication with their species: for we can hardly bring ourselves to believe, that the parent bird informed her unfledged pupil of the history of hergestation, her timely preparation of her nest, her exclusion of the eggs, her long incubation, and of the joyful eruption at last of her expected offspring; all which the bird in the cage must have learnt in her infancy, if we resolve her conduct into institution.

ted from one generation to another. There is no opportunity either for instruction or imitation. The parent race is gone, before the new brood is hatched. And if it be original reasoning in the butterfly, it is profound reasoning indeed. She must remember her caterpillar state, its tastes and habits: of which memory she shows no signs whatever. She must conclude from analogy (for here her recollection cannot serve her), that the little round body which drops from her abdomen, will at a future period produce a living creature, not like herself, but like the caterpillar which she rembembers herself once to have been. Under the influence of these reflections, she goes about to make provision for an order of things, which she concludes will, some time or other, take place. And it is to be observ. ed, that not a few out of many, but that ail Unless we will rather suppose, that she re-butterflies argue thus; all draw this conclu members her own escape from the egg; had sion; all act upon it.

But suppose the address, and the selection, ter? The undisclosed grub, the animal which and the plan, which we perceive in the prepa- she is destined not to know, can hardly be the rations which many irrational animals make object of a particular affection, if we deny the for their young, to be traced to some probable influence of instinct. There is nothing, thereorigin; still there is left to be accounted for, fore, left to her, but that of which her nature that which is the source and foundation of seems incapable, an abstract anxiety for the these phenomena, that which sets the whole general preservation of the species; a kind of at work, the rogyn, the parental affection, patriotism; a solicitude lest the butterfly race which I contend to be inexplicable upon any should cease from the creation. other hypothesis than that of instinct.

Lastly, the principle of association will not For we shall hardly, I imagine, in brutes, explain the discontinuance of the affection when refer their conduct towards their offspring to the young animal is grown up. Association, a sense of duty, or of decency, a care of repu- operating in its usual way, would rather protation, a compliance with public manners, with duce a contrary effect. The object would bepublic laws, or with rules of life built upon a come more necessary, by habits of society; long experience of their utility. And all at- whereas birds and beasts, after a certain time, tempts to account for the parental affection banish their offspring; disown their acquaint from association, I think, fail. With what is ance; seem to have even no knowledge of the it associated? Most immediately with the objects which so lately engrossed the attention throes of parturition, that is, with pain and of their minds, and occupied the industry and terror and disease. The more remote but not labour of their bodies. This change, in difless strong association, that which depends ferent animals, takes place at different distanupon analogy, is all against it. Every thing ces of time from the birth; but the time alelse, which proceeds from the body, is cast ways corresponds with the ability of the young away, and rejected. In birds, is it the egg animal to maintain itself; never anticipates it. which the hen loves? or is it the expectation In the sparrow tribe, when it is perceived that which she cherishes of a future progeny, that the young brood can fly, and shift for themkeeps her upon her nest? What cause has she selves, then the parents forsake them for ever: to expect delight from her progeny? Can any and though they continue to live together, pay rational answer be given to the question, why, them no more attention than they do to other prior to experience, the brooding hen should birds in the same flock. I believe the same look for pleasure from her chickens? It does thing is true of all gregarious quadrupeds. not, I think, appear, that the cuckoo ever knows In this part of the case, the variety of re her young; yet, in her way, she is as careful sources, expedients, and materials, which aniin making provision for them as any other mals of the same species are said to have rebird. She does not leave her egg in every course to, under different circumstances, and hole. when differently supplied, makes nothing aThe salmon suffers no surmountable obsta-gainst the doctrine of instincts. The thing cle to oppose her progress up the stream of which we want to account for, is the propen. fresh rivers. And what does she do there? sity. The propensity being there, it is proShe sheds a spawn, which she immediately bable enough that it may put the animal upquits, in order to return to the sea: and this on different actions, according to different exiissue of her body, she never afterwards recog-gencies. And this adaptation of resources nises in any shape whatever. Where shall we may look like the effect of art and considerafind a motive for her efforts and her persever- tion, rather than of instinct: but still the ance? Shall we seek it in argumentation, or propensity is instinctive. For instance, supin instinct? The violet crab of Jamaica per- pose what is related of the woodpecker to be forms a fatiguing march of some months' con- true, that in Europe she deposits her eggs in tinuance from the mountains to the sea-side. cavities, which she scoops out in the trunks When she reaches the coast, she casts her of soft or decayed trees, and in which cavi spawn into the open sea, and sets out upon her ties the eggs lie concealed from the eye, and return home. in some sort safe from the hand of man: but Moths and butterflies, as hath already been that, in the forests of Guinea and the Brazils, observed, seek out for their eggs those precise which man seldom frequents, the same bird situations and substances in which the offspring hangs her nest to the twigs of tall trees, caterpillar will find its appropriate food. That thereby placing them out of the reach of dear caterpillar, the parent butterfly must never monkeys and snakes, i. e. that in each situasee. There are no experiments to prove that tion she prepares against the danger which she she would retain any knowledge of it, if she has most occasion to apprehend; suppose, I did. How shall we account for her conduct? say, this to be true, and to be alleged, on the I do not mean for her art and judgment in se- part of the bird that builds these nests, as evilecting and securing a maintenance for her dence of a reasoning and distinguishing preyoung, but for the impulse upon which she caution: still the question returns, whence What should induce her to exert any the propensity to build at all? art, or judgment, or choice, about the mat- Goldsmith's Natural History, vol. iv. p. 244

acts.

the case is the same with ants.

which the scent issued, was the material of its food. It had never tasted milk before its birth. None of the animals which are not designed for that nourishment, ever offer to suck, or to seek out any such food. What is the conclusion, but that the sugescent parts of animals are fitted for their use, and the knowledge of that use put into them?

We assert, secondly, that, even as to the cases in which the hypothesis has the fairest claim to consideration, it does not at all lessen the force of the argument for intention and design. The doctrine of instincts is that of ap

Nor does parental affection accompany generation by any universal law of animal organization, if such a thing were intelligible. Some animals cherish their progeny with the most ardent fondness, and the most assiduous attention; others entirely neglect them: and this distinction always meets the constitution of the young animal, with respect to its wants and capacities. In many, the parental care extends to the young animal; in others, as in all oviparous fish, it is confined to the egg, and, even as to that, to the disposal of it in its proper element. Also, as there is generation without parental affection, so is there pa-petencies, superadded to the constitution of an rental instinct, or what exactly resembles it, animal, for the effectuating of a purpose bene. without generation. In the bee tribe, the ficial to the species. The above-stated solugrub is nurtured neither by the father nor the tion would derive these appetencies from ormother, but by the neutral bee. Probably ganization; but then this organization is not less specifically, not less precisely, and, thereI am not ignorant of the theory which re-fore, not less evidently adapted to the same solves instinct into sensation; which asserts, ends, than the appetencies themselves would that what appears to have a view and relation be upon the old hypothesis. In this way of to the future, is the result only of the present considering the subject, sensation supplies the disposition of the animal's body, and of pleasure place of foresight: but this is the effect of conor pain experienced at the time. Thus the in-trivance on the part of the Creator. Let it cubation of eggs is accounted for by the plea-be allowed, for example, that the hen is indusure which the bird is supposed to receive trom the pressure of the smooth convex surface of the shells against the abdomen, or by the relief which the mild temperature of the egg may afford to the heat of the lower part of the body, which is observed at this time to be increased beyond its usual state. This present gratification is the only motive with the hen for sitting upon her nest; the hatching of the chickens is, with respect to her, an accidental consequence. The affection of viviparous animals for their young is, in like manner, solved by the relief, and perhaps the plea-turity? In my opinion, this solution, if it be sure, which they receive from giving suck. accepted as to the fact, ought to increase rather The young animal's seeking, in so many in- than otherwise, our admiration of the contrivstances, the teat of its dam, is explained from ance. A gardener lighting up his stoves, just its sense of smell, which is attracted by the when he wants to force his fruit, and when his odour of milk. The salmon's urging its way trees require the heat, gives not a more cerup the stream of fresh-water rivers, is attri-tain evidence of design. So again; when a buted to some gratification or refreshment, male and female sparrow come together, they which, in this particular state of the fish's do not meet to confer upon the expediency of body, she receives from the change of ele-perpetuating their species. As an abstract ment. Now of this theory it may be said,

ced to brood upon her eggs by the enjoyment or relief, which, in the heated state of her abdomen, she experiences from the pressure of round smooth surfaces, or from the applica tion of a temperate warmth. How comes this extraordinary heat or itching, or call it what you will, which you suppose to be the cause of the bird's inclination, to be felt, just at the time when the inclination itself is wanted: when it tallies so exactly with the internal constitution of the egg, and with the help which that constitution requires in order to bring it to ma

proposition, they care not the value of a barFirst, that of the cases which require solu- ley-corn, whether the species be perpetuated, tion, there are few to which it can be applied or not; they follow their sensations; and all with tolerable probability; that there are none those consequences ensue, which the wisest to which it can be applied without strong ob- counsels could have dictated, which the most jections, furnished by the circumstances of solicitous care of futurity, which the most the case. The attention of the cow to its anxious concern for the sparrow-world, could calf, and of the ewe to its lamb, appear to be have produced. But how do these consequen prior to their sucking. The attraction of the ces ensue? The sensations, and the constitu calf or lamb to the teat of the dam, is not ex-tion upon which they depend, are as manifestplained by simply referring it to the sense of ly directed to the purpose which we see ful smell. What made the scent of milk so agree-filled by them,) and the train of intermediate able to the lamb, that it should follow it up effects, as manifestly laid and planned with a with its nose, or seek with its mouth the place from which it proceeded? No observation, no experience, no argument could teach the ew-dropped animal, that the substance from

view to that purpose: that is to say, design is as completely evinced by the phenomena, as it would be, even if we suppose the operations to begin, or to be carried on, from what some