Salmonia; Or, Days of Fly Fishing / In a series of conversations. With some account of the habits of fishes belonging to the genus Salmo

by Sir Humphry Davy

Orn.—I find I must multiply examples. Examine young ducks which have been hatched under a hen; they no sooner quit the shell, than they fly to their natural element, the water, in spite of the great anxiety and terror of their foster-parent, who in vain repeats that sound to which her natural children are so obedient. Being in the water, they seize insects of every kind, which they can only know from their instincts to be good for food; and when they are hatched in the May-fly season, they pursue these large ephemeræ with the greatest avidity, and make them their favourite food. It is impossible, I think, to explain these facts, except by supposing, that they depend upon feelings or desires in the animals developed with their organs, which are not acquired, and which are absolutely instinctive. I will mention another instance. A friend of mine was travelling in the interior of Ceylon; on the banks of a lake he saw some fragments of shells of the eggs of the alligator, and heard a subterraneous sound: his curiosity was excited, and he was induced to search beneath the surface of the sand: besides two or three young animals lately come from the shell, he found several eggs which were still entire: he broke the shell of one of them, when a young alligator came forth, apparently perfect in all its functions and motions; and when my friend touched it with a stick, it assumed a threatning aspect, and bit the stick with violence. It made towards the water, which (though born by the influence of the sunbeams on the burning sand) it seemed to know was its natural and hereditary domain. Here is an animal which, deserted by its parents, and entirely submitted to the mercy of nature and the elements, must die if it had to acquire its knowledge; but all its powers are given, all its wants supplied; and even its means of offence and defence implanted by strong and perfect instincts. I will mention one fact more. Swallows, quails, and many other birds, migrate in large flocks when their usual food becomes scarce; and in these cases it may be said (I anticipate a remark of Physicus), that the phenomenon depends upon imitation, and that the young birds follow the old ones who have before made the same flight. But I will select the young cuckoo for an unexceptionable example of the instinctive nature of this quality. He is produced from an egg deposited by his mother in the nest of another bird, generally the hedge sparrow. He destroys all the other young ones hatched in the same nest, and is supplied with food by his foster-parent, after he has deprived her of all her natural offspring. Quite solitary, he is no sooner able to fly than he quits the country of his birth, and finds his way, with no other guide than his instinct, to a land where his parents had gone many weeks before him; and he is not pressed to make this migration by want of food, for the insects and grains on which he feeds are still abundant. The whole history of the origin, education, and migration of this singular animal, is a history of a succession of instincts, the more remarkable, because in many respects contrary to the usual order of nature.

Phys.—I have been accustomed to refer many of the supposed instincts of animals, such as migrations, building nests, and selection of food, to imitation; but, I confess, I cannot explain the last fact you have brought forward on this principle. Pray, Ornither, let me state your view, as I understand it, that we may not differ as to the meaning of language. I conclude you adopt Hartley’s view of association, that the motions of the muscles in man are first automatic, and become voluntary by association; and that reason is the application of voluntary motions for a particular end. For instance: a child is not afraid of fire, but, bringing its hand near the fire, it is burnt, and the convulsions of the muscles produced by the pain ends in removing the hand from the source of pain. These motions by association are made voluntary; and after this experiment he avoids the fire by reason, and takes care always to perform those motions which remove his limbs from this destructive agent. But in contrasting instinct with this slow process, you would say, most animals, without having felt the effects of fire, have an innate dread of it; and in the same way, without having been taught, or experienced pleasure or pain from the object, young ducks seek the water, young chickens avoid it: their organs have a fitness or unfitness for certain functions, and they use them for these functions without education. In short, the instinctive application of the organ is independent of experience, and forms part of a train of pure sensations.

Orn.—I have no objection to the statement you make of my view of the subject; but I certainly should give to it a little more refinement and generality. In all the results of reason, ideas are concerned but never in those of instinct. Without memory there can be no reason; but in instinct nothing can be traced but pure sensation.

Poiet.—Though in the animal world no ideas seem connected with instincts, yet they are all intended for specific and intelligent ends. Thus the swallow travels to a country where flies are found; the salmon migrates from the sea to the sources of fresh rivers, where its eggs may receive a supply of aerated water, and without this migration the race would be extinct: and in this way all the instincts of animals may be referred to intelligence, which, though not belonging to the animal, must be attributed to the Divine Mind. Is it not then reasonable to refer instinct to the immediate impulse of the Author of Nature upon his creatures? His omnipresence and omnipotence cannot be doubted, and to the infinite mind the past, the present, and the future are alike; and creative and conservative power must equally belong to it.

Hal.—That instincts depend upon impulses immediately derived from the Deity is an opinion which, though it perhaps cannot be confuted, yet does not please me so much as to believe them dependent upon the formation of organs, and the result of the general laws which govern the system of the universe; and it is in favour of this opinion that they are susceptible of modifications. Thus, in domesticated animals they are always changed; the turkey and the duck lose their habits of constructing nests, and the goose does not migrate. In supposing them the result of organization and hereditary, they might be expected to be changed by circumstances, as they are actually found to be. Without referring the instincts of animals to the immediate impulse of the Deity, they appear to me to offer the most irresistible and convincing argument that can be brought forward against atheism. They demonstrate combinations, the result of the most refined intelligence, which can only be considered as infinite. Take any one of the lowest class of animals, insects for instance, not only is their organization fitted to all their wants; but their association in society is provided for, and the laws of a perfect social community, as it were, are adopted by beings, that we are sure cannot reason. In the hive bee, for instance, the instinct of the workers leads them to adopt and obey a queen; and if she is taken away from them, or dies, they have the power of raising another from offspring in the cells by an almost miraculous process: they work under her government for a common object, allow males only to exist for the purpose of impregnating females, who preserve the society, and under whose government they send forth swarms, which readily place themselves under the protection of man. In the geometrical construction of their cells, the secretion of wax from their bodies, the collecting their food, and the care of the brood, there is a series of results which it requires a strong reason to follow, and which are the consequences of invariable instincts. Bees, since they have been noticed by naturalists, have the same habits, and, as it is probable that there have been many thousand of generations since the creation, it is evident, that the instincts of the first bees have been hereditary and invariable in their offspring; and it cannot be doubted, that they do now, as they did four thousand years ago, make some cells in combs larger than others for the purpose of containing the eggs and future grubs of drones, that are to be produced by a grub, which they are educating for a queen bee; and that these cells are connected with the common cells by a series, in which the most exact geometrical laws of transition are observed. An eminent philosopher has deduced an argument in favour of the existence of Deity from the analogy of the universe to a piece of mechanism, which could only be the work of an intelligent mind; but there is this difference: in all the productions of nature, the principle, not only of perfection, but likewise of conservation, is found, marking a species of intelligence and power which can be compared to nothing human. The first created swarm of bees contained beings provided with all the instincts necessary for the perpetual continuance of the species; and some of these instincts can scarcely be understood by man, requiring the most profound geometrical knowledge, even to calculate their results; and other instincts involve what in human society would be the most singular state of policy, combining contrasted moral causes and contradictory interests. It is impossible not to be lost in awe at the contemplation of this chain of facts; the human mind cannot fail to acknowledge in them the strongest proofs of their being produced by infinite wisdom and unbounded power; and the devout philosopher can scarcely avoid considering with respect a little insect, endowed with faculties producing combinations, which human reason vainly attempts to imitate, and can scarcely understand.

Phys.—I agree with you, that if instinct be supposed the result of organization, and that the first animal types were so created as to transmit their instincts invariably, generation after generation, it does offer a most triumphant and incontrovertible argument for the existence of an all-powerful intelligent Cause.—Even in the instance which led to this conversation, the instinct which carries salmon from the sea to the sources of rivers, it is only lately philosophers have discovered, that the impregnated eggs cannot produce young fishes independent of the influence of air; and thus an animal goes many hundred miles under the direction of an instinct, the use of which human reason has at length developed, and man is supplied with an abundant food by the result of a combination, in consequence of which a species is preserved.

Poiet.—I do not understand, Halieus, your objections to the view I have adopted, which is sanctioned by the authority of a good ethic philosopher, Addison. Allowing the omnipresence and constant power of Deity, I do not see how you can avoid admitting his actual interference in all the phenomena of living nature.

Hal.—As I said before, I cannot confute your view; but, upon this principle, gravitation and the motion of the planets round the sun, and all the other physical phenomena of the universe, would be owing to the immediate action of the Divinity. I prefer the view, which refers them to motion and properties, the results of general laws impressed on matter by Omnipotence. This view is, I think, simpler; but it is difficult to form any distinct opinion on so high and incomprehensible a subject, on which, perhaps, after all, it is wiser to confess our entire ignorance, and to bow down in humble adoration to the one incomprehensible Cause of all being.

Poiet.—I agree with you in your last sentence, but I still adhere to my own view, and I hope you will not object to a favourite opinion of mine, that instincts are to animals what revelation is to man, intended to supply wants in their physical constitution, which in man are provided for by reason; and that revelation is to him as an instinct, teaching him what reason cannot—his religious duties, the undying nature of his intellectual part, and the relations of his conduct to eternal happiness and misery.

Hal.—“Davus sum, non Œdipus.” I will not attempt to discuss this view of yours, Poietes; but I think I may say, that all the instincts of animals seem to be connected with pleasure; and in man the feeling of love and the gratifying the appetites, which approach nearest to instincts, are likewise highly delightful, and perhaps there is no more pleasurable state of the human mind than when, with intense belief, it looks forward to another world and to a better state of existence, or is absorbed in the adoration of the supreme and eternal intelligence.