Thus it plainly appears, that the instinct of each animal is adapted to its proper sphere; for the mode of life it was destined to pursue, and for that only.  With this restriction (if such it can be called), it is in each case perfect.  The actions of every creature uncontrolled and uninfluenced by man are invariably such as tend to the general welfare of its species; sometimes collectively, however, rather than individually (whence we hear of what have been termed "mistakes of instinct").⁷
   They evince superhuman wisdom, because it is innate, and, therefore instilled by an allwise Creator.  Indeed, the unpremeditated resource of animals, in cases of emergency, is oftentimes decidedly superior to that of man; and why?  Because they need not experience for their guide, but are prompted to act aright by intuition.

In wild nature, this inborn knowledge of brutes thus abundantly sufficing for the attainment of all they require, there is, in consequence, but little to stimulate the exercise of their reflective faculties; and, accordingly, their general agency may be considered as passive, in effect analogous to the operation of the laws of matter.  Even the "half-reasoning elephant," in the wild woods, is but a creature of unreflecting impulse, to an extent which wholly dissevers it from all community of mental attribute with the lowest grade of mankind.
   Witness the subdued tamed animal, which, travelling along its accustomed route, suddenly broke loose from its attendants, affrighted at the near yell of a tiger.  At once its former submissiveness was forgotten: it rejoined the wild troops, and was again a free tenant of the jungle.  Years rolled on, and it was retaken by the ordinary method.  The sight of the stakes never sufficed to awaken its recollection; nor did the mode employed to secure it when entrapped.  It was sullen and savage, and acted in nowise differently from its companions.  By chance, however, its former keeper was present, who, after a while, recognised the animal.  He gave the word of command, and it was instantly submissive; all traces of its wild nature suddenly dissipated; its previous habits were forgotten; it was once more a reclaimed animal, and suffered itself to be led tractably to its place of confinement.
   Would a rational being have acted like this elephant?

Man only, by the habitual exercise of his reasoning powers, appears to be competent to trace effects to their remote causes; and is thereby enabled to recognise the existence of abstract laws, by assuming the guidance of which he can intentionally modify their operation, or, from observation, convert them to a means of accomplishing his various ends.  It is thus he wields the principle of gravitation; and it is thus, from studying the inherent propensities and consequent habits of other animals, that, by judicious management, he contrives to subdue their instincts (as in the case of the elephant just mentioned), or to direct their force towards affecting other purposes than those for which they were more legitimately designed.  But a more remarkable sequence of human interference is that by removing animals from their proper place in nature, and training them to novel modes of life, wherein the field for the exercise of their original instincts becomes much limited, their faculties of observation and reflection are, in consequence, brought more into play, in proportion as the former are rendered inefficient; till, at length, experience not unfrequently supersedes innate impulse as the main spring of their actions; more especially where they have become attached to a human master, and pass much of their time in his society.  Yet even here the difference between man and brute is still manifest, in the transmission of acquired knowledge by generation, in the offspring inheriting as innate instincts the experience of their parents; so that the tendency of brutes is ever to become slaves to a certain amount of intuition, rather than beings dependent on their own intelligence.⁸

And here we recognise a fundamental principle of domestication, which is only gradually induced to any extent through a series of generations.  Thus the elephant, though tamed, is not domesticated, for every individual is separately captured in a wild state; and we have seen that, when one of these returns to its proper haunts, its natural instincts having been only for a time subdued and rendered subservient (not eradicated), these have again become the incentives to its conduct, to the exclusion of those reasoning faculties which had only been excited into action under circumstances adverse to the efficient operation of the former.  Far otherwise is what we observe in animals truly domesticated: witness the opposite conduct of even the newly hatched progeny of a wild and domestic duck, though incubated by the same bird.  But here a question arises, that, as numerous instincts in domestic animals, which are now hereditary, are known to have been originally habits superinduced by man's agency, to what extent may not all the innate propensities and consequent habits of animals have originated in the acquired experience of their predecessors?

As with all other subjects, we must trace the series upward from its more simple phases.  In the insect world, we discern the most complicated instincts; modes of procedure of which the consummate wisdom excites our admiration and amazement, and bearing reference to a future generation, in beings which are but creatures of an hour.  Can it be supposed possible that the progenitors of these derived their habits from acquired experience, and transmitted them as innate instincts to their posterity?  Here we must ascend to a higher source, which, being admitted, the marked uniformity, also, of the instinctive habits of all wild animals, before commented on, warrant us in concluding that these were from the first imprinted in their constitution, and may, therefore, be legitimately esteemed as forming part of the specific character.⁹

The tendency of human influence is everywhere to destroy whatever conduces not to man's enjoyment, as superfluous, and only cumbering the ground; but to secure, by every means the reasoning faculties can suggest, a due continuance and neverfailing supply of all that tends to the gratification of our species.
   Brutes, on the contrary, evince indifference to whatever does not immediately concern them; and although, practically, their influence upon their prey is for the most part decidedly conservative, yet they individually continue to destroy without reflection, and endeavour not, by any forbearance, or plan resulting from reasoning, to insure the perpetuity of their provision.  That the squirrel or jay should instinctively plant acorns is, of course, nothing whatever to the purpose: we have already tested the sagacity of the former animal; and we know that the latter, removed from its proper office in wild nature, will bury a bit of glass or clipping of tin as carefully as it does a seed.

It may be worth while to devote a few remarks to the consideration of the unintentional agency of brutes, towards not only preventing the over-increase of their prey, which would only lead to too much consumption of the food of the latter, and so bring about famine and consequent degeneration from insufficiency of nutriment, but likewise towards preserving the typical character of their prey in a more direct manner, by removing all that deviate from their normal or healthy condition, or which occur away from their proper and suitable locality, rather than those engaged in performing the office for which Providence designed them.
   In illustration, it will be sufficient to call attention to the principle on which many birds of prey are enabled to discern their quarry.  When the tyrant of the air appears on wing, his dreaded form is instantly recognised by all whose ranks are thinned for his subsistence; and instinct prompts them to crouch motionless, like a portion of the surface, the tint of which all animals that inhabit open places ever resemble; so that he passes over, and fails to discriminate them, and seeks perchance in vain for a meal in the very midst of abundance; but should there happen to be an individual incapacitated by debility or sickness to maintain its wonted vigilance, or should its colours not accord sufficiently with that of the surface, as in the case of a variety, or of an animal pertaining to other and diverse haunts, that creature becomes, in consequence, a marked victim, and is sacrificed to appease the appetite of the destroyer: so profoundly wise are even the minor workings of the grand system; and thus do we perceive one of an endless multiplicity of causes which alike tend to limit the geographical range of species, and to maintain their pristine characters without blemish or decay to their remotest posterity.¹⁰

Thus it is that, however great may be the tendency of varieties to perpetuate themselves by generation, we do not find that they can maintain themselves in wild nature; nor do the causes which induce variation, beyond the occasional and very rare occurrence of an albino, prevail in those natural haunts of species to which their structural adaptations bind them.  We have already noticed the anomalous influence of human interference in altering the innate instincts of the lower animals, thereby unfitting them to pursue the mode of life followed by their wild progenitors.  It would be needless to amplify on the concomitant effects produced by domestication on the changes in the physical constitution and adaptations of the corporeal frame of animals, which oftentimes render them dependent on human assistance for continuous support, in the degree of their domesticity.  Such changes are equally imposed on the vegetable world by cultivation; and they everywhere mark the progress of man, and exhibit in indisputable characters the diversity of his influence over the inferior ranks of creation, from any mutual and reciprocal influence observable among these latter.

I may cursorily allude to hybridism also, as a phenomenon, as far as can yet be shown, at least in animals, where fecundation cannot happen fortuitously, in every instance referable to human interference.  As yet, I have failed to meet with a single satisfactory instance, wherein commixture of species could not be directly traced to man's agency, in superimposing a change on the constitution of the female parent.  This is a subject of exceeding interest; and I am glad to avail myself of every occasion to endeavour to incite some to undertake its further investigation.  There can be little doubt that certain of our domestic races, as the common fowl, are derived from a plurality of species, which, however, do not blend in wild nature; so that their union (assuming the hypothesis to be correct) may here, at least, be fairly ascribed to domestication.  Still, when we consider that separate species (i. e., races not descended from a common stock) exhibit, as is well known, every grade of approximation, from obviously distinct to doubtfully identical, there appears, I think, sufficient reason at least to suspect that circumstances may sometimes combine to induce those nearest allied to commingle.
That the mixed progeny, too, would in some instances be mutually fertile, I know in the case of the hybrid offspring of the Anser cygnoides, and the common goose; but, in birds generally, the converse nevertheless obtains, as is particularly instanced, I have learned, by the hybrid Fringillidae reared in confinement; and also the mule betwixt the common fowl and pheasant; the males of all which appear (from a variety of instances I have been fortunate in collecting) to have been incompetent to fecundate the eggs produced.¹¹  Perhaps the superior size, too, of these hybrids generally to that of either of their parent species may be explicable on the principle which occasions the large growth of capons.  However, none of the species here alluded to are by any means so closely allied as many that are known to exist; and, therefore, as in the vegetable world the degree of fertility in hybrids is in the ratio of that of affinity between the parents, those derived from very approximate species being, apparently, quite as prolific as the pure race, analogy would lead us to infer that the same law holds in the animal creation.  At present, we have no proof of it: and I may conclude the subject by observing that the cases of supposed union (apart from human influence) betwixt the carrion and hooded crows, so often insisted on, are inconclusive, inasmuch as it does not appear that the individuals were ever examined and compared, although black varieties of Corvus cornix have been several times known to occur.  Indeed, I have myself examined a female specimen, on which were several black feathers intermingled with the ordinary ash colour on the back.¹²

The agency of the human race has been likened to that of brutes, in the particular that, as man effects the destruction of one species, he necessarily advances the interests of another.
   How far he may permanently benefit the latter, might be discussed on principles that have been already expounded.  More able writers, however, have put the inquiry whether man, by taking certain plants, for instance, under his protection, and greatly extending their natural range by cultivation, does not thereby unintentionally promote the welfare of the various species which subsist upon them.  But, will it be argued that man, by vastly increasing the breed of sheep, is unconsciously labouring for the advantage of the wolves?  As little can it be concluded, regarding the human race as progressive (in which it differs from all other species), that any race hostile to man's interests can be permanently benefited by his agency.  The question, in short, resolves itself into one of time.