The anonymous reviewer attempts through logical argument and copious examples drawn from natural history to shed doubt upon Darwin's Theory of Natural Selection, but in doing so acknowledges the sweeping theological implications of the Darwinian "hypothesis."
If Mr. Darwin's theory be true, nothing can prevent its ultimate and general reception, however much it may pain and shock those to whom it is propounded for the first time. If it be merely a clever hypothesis, an ingenious hallucination, to which a very industrious and able man has devoted the greater and the best part of his life, its failure will be nothing new in the history of science. ["Natural Selection," 299]
All the Year Round, Volume 3 (1860): 174-77. — An anonymous review of Charles Darwin's Origin of Species, published on 24 November 1859]
ONE of the earliest duties and pleasures of Adam in his Paradise was the studying and the naming of the multitudes of living creatures which passed in long review before him. In these latter days, the highest and the most refined intellects have found their greatest gratification in working out the same task. They have separated all living organised things into two grand allied kingdoms — Animals and Vegetables; but, as animal life appears at first sight utterly distinct from vegetable life, the study of the first has been called Zoology, a discoursing on life; while the second is content to be designated by the term Botany (Botanology it should have been), the science of herbs.
The Animal Kingdom comprises a much greater variety of forms and conditions than the Vegetable. There are beasts of two kinds: mammals, those that have outer breasts; and marsupials, as kangaroos, which rear their young in a pouch. There are birds; reptiles; fishes; star-shaped animals, built on a radiating plan; ringed animals, as earthworms; incrusted animals, as crabs and lobsters; insects, and others. All these are subdivided into classes, orders, families, genera, species, and varieties. Thus, the genus Canis, which gives its name to the Canidae, the great family of dogs, contains as species the fox, the jackal, the wolf, and the domestic dog. The domestic dog species branches into the varieties of hound, beagle, mastiff, Newfoundland, terrier, and other well-known forms.
Vegetables are also divided into families, genera, species, and varieties. In the Rosaceae, the grand family of rose-like plants, are comprised many genera, quince, apple, medlar, hawthorn; peach, plum, cherry, apricot; bramble, strawberry, potentilla, besides the roses proper. Of the genus Pyrus, P. malus, the wild crab-apple, is one species; P. communis, the thorny wild pear, is another. Of these two species our dessert and kitchen apples and pears are varieties. [174/175]
The genus Rosa, has many species; from the variation of certain species our garden varieties have accidentally arisen, although some of these have been artificially obtained by cross-breeding between two other varieties, or species. Varieties from species both of plants and animals are found in a wild as well as in a domesticated state. Albino, or white red-eyed rats, sparrows blackbirds, etc., are constantly being caught. The albinos of green birds are yellow, whence our cage canary, whose wild progenitor is a green- plumaged finch. The fields and the hedgerows annually yield plants with variegated and mottled leaves; less frequently, but still occasionally, with torn or ragged leaves. Mr. Lubbock has recently demonstrated that the muscles in the larvae of certain insects are far from uniform. Species are universally acknowledged to be continually sending forth varieties, in greater or less number, some more frequently than others; and varieties to be varying to a slight extent; indeed, their deficient permanency is their chief characteristic. Man has often to exert all his art to render them stationary and permanent enough for his own convenience. Genera are merely bundles of species arbitrarily grouped together, and may at any time be revised if science require. A large genus, containing very dissimilar species, may be split into two; or two very closely allied genera may be united into one. Genera can be regarded as fixed no further than the species of which they are composed are fixed, and as the judgment of scientific men shall decide to fix them. What, then, is the nature of species — are they immutable and permanent, or do they vary? Let us call this, Question the First.
Question the Second. — What is the Origin of Species?
To these questions (the second of which Is the mystery of mysteries) opposing answers have been given. The first is, that species are fixed, and do not vary upon the whole, but transmit their own identical qualities and forms to their seed, or offspring, and will continue so to transmit them to the end of time; that varieties either die out, or revert to their original species, or continue to vary within such narrow limits as not to separate them from their parent species; that cross- breeds between two distinct species are barren and are unable to reproduce an intermediate species that shall last and maintain its ground without falling back to one parent species or the other — this property is one that has been assumed to decide whether a species is a species, or a mere variety; varieties may produce fertile offspring, and species not; and, lastly, that each species, was originally and independently created, as we now see it, by the fiat of the Almighty Maker.
God said, Let th' earth bring forth soul living in her kind, Cattle and creeping things, and beast of th' earth, Each in their kind. The Earth obey'd, and straight Opening her fertile womb teem'd at birth Innumerous living creatures, perfect forms, Limb'd and full-grown: out of the ground up rose As from his lair the wild beast where he wons [sic] In forest wild, in thicket, brake, or den; The grassy clods now calv'd, now half appear'd The tawny lion, pawing to get free His hinder parts, then springs as broke from bonds, And rampant shakes his brindled mane; the ounce, The libbard, and the tiger, as the mole Rising, the crumbled earth above them threw In hillocks: the swift stag from under ground Bare up his branching head. — At once came forth whatever creeps the ground, Insect or worm.
But geologists have discovered that the earth bears what seem to be traces of grand convulsions, in which successive sets of living creatures lie buried. Answer the First explains them by admitting the convulsions (of which the last is Noah's deluge), and by believing that each successive fauna, or animal population of the world, was called into being by a separate creative act of the Great Artificer; that every animal and plant, at its creation, was providentially and purposely adapted to the circumstances in which it was placed, and, needing no change, was susceptible of none; that a species, like an individual, might be swept away when its allotted term of existence was completed, but could hardly be altered. Answer the First agrees with the views eloquently expressed in Paley's Natural Theology. Authors of the highest eminence seem to be fully satisfied with the view that each species of beast, bird, insect, and plant, has been independently created.
Answer the Second (which has been gradually gaining ground and has obtained a fuller acceptance amongst a limited group of scientific men) tells us that we search in vain for the undiscovered and undiscoverable essence of the term species. Various definitions have been given; but not one of them has as yet satisfied all naturalists, although every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation. Every one admits that there are at least individual differences in species in a state of nature; but certainly no clear line of demarcation has as yet been drawn between species and sub-species — that is, the forms which in the opinion of some naturalists come very near to, but do not quite arrive at, the rank of species; or, again, between sub-species and well-marked varieties, or between lesser varieties and individual differences. These differences blend into each other in an insensible series; and a series impresses many minds with the idea of an actual passage.
And here arises a point of considerable interest, Is it logical, or is it not, to infer that, because we behold a series of forms, there has been an actual transition from one form to that next above it? The whole dispute at issue rests on the effect which this consideration has on the mind. Some minds will accept the passage, others will not. Every one will allow that a series of plants can be made out, from the [175/176] microscopic yeast-plant to the branching oak; and a series of vertebrated animals, from the worm-like lamprey to the orang-otang; but not every one will admit, as a consequence, the theory that all plants are only gradual developments of a minute mould, and all animals the improved descendants of some primitive creature from which the lamprey itself is descended. In searching after the original condition of existing forms, some minds may suspect that the circumstance of finding that nature is composed of various regular series of forms, has been made to prove much more than it ought to be allowed to prove. Laplace's celebrated comparison of the nebulae, in what are supposed progressive stages of forwardness, to the trees of different ages growing in a forest, has appeared to some minds as assuming too much. Certain stars called nebulae, beheld with the best existing telescopes, have an ill-defined and cloudy look; others are less and less so, till we arrive at the perfect, point-like, glittering star, or cluster of stars, shining like diamonds in the sky. Hence it was concluded that these groups of suns are in a state of transition, passing from a vapoury chaos of inconceivable heat, into the coolness, arrangement, and order of our own system. But Lord Rosse builds a telescope of unprecedented power, and those cloudy stars, the imagined chaotic burning nebulae, are beheld as groups of gold-dust, each grain a sun, doubtless with its attendant worlds. If what is said of Lord Rosse's telescope be true, and that the nebulae are likely to prove all resolvable with improved instruments, and not to be in different stages of growth, the comparison fails, and we see how little trust we ought to put in this interpretation of a series — namely, that any one individual form must have passed in succession through those that are nearest below it in the chain. But, as the force of the argument will entirely depend on the peculiar turn of mind of the individual to whom it is addressed, it is only fair to take note of it.
Answer the Second would further suggest that life may originate, either in what is called the spontaneous generation of a multitude and variety of organised beings of the simplest class, or from a very few primordial forms into which life was first breathed by the Creator. Varieties of these would produce something more nearly perfect and more highly organised; and of these, again, the best only would survive, to be the parents of something still nearer perfection; and so on, till animated and vegetable nature became what we see around us. No grand cataclysms on the earth are needed; the fossil remains of former geological epochs are merely the dead bodies of creatures which have died out because they were overpowered or pushed aside by stronger rivals in the contest for the means of subsistence. Every existing creature is the lineal descendant of some creature that has lived before it; there have been no successive new creations at successive geological epochs. There often exist parts in an animal's organisation — such as rudimentary teeth which never bite, rudimentary feet which never walk, and rudimentary wings which never fly — that cannot be explained by the final causes of adaptation and providential contrivance; therefore, the final causes of adaptation and contrivance, it is said, are inadequate to explain the peculiarities of a creature's organisation. Because it has them, it has survived during the process of natural selection; if it had not had them, it would have perished and disappeared; that is all. And so have arisen the immense variety of living creatures which we see around us.
This view is not necessarily irreligious, as it seems to be at the outset; for it does not deny the existence of a Supreme Overruling Power, although acting in a manner to which the minds of men in general are little accustomed; nor of a Sustaining and Regulating Influence, although the desired ends are brought about by contrivances which unthinking persons might call accident. But God is Continuous and Unyielding Law, and Incessant Energy, and All-pervading Life; and all those we behold around us wherever we direct our eyes. Whether we conceive many successive creative acts, or few, or only one, a creation once in existence must be sustained, not from day to day, and from hour to hour, but from half-second to half-second, without the intermission of the smallest imaginable fragment of time. But the creation which we see around us is so complicated and perfect, that it can only be sustained by an All-wise, Almighty Divinity. The greater the complexity of the machinery which is kept in action, the greater must be the energy and the untiring power of the eternal mainspring. It may be just as noble a conception of the Deity to believe that he created a few original forms capable of self-development into other and needful forms, as to believe that He required a fresh act of creation to supply the voids caused by the action of His laws.
In any case, it is clear that the innumerable species inhabiting this world have been modelled somehow, so as to be in possession of that perfection of structure and coadaptation which most justly excites our admiration. The how, religiously considered, may be a question of mode rather than of principle. Whether a wonderful adaptation of structure be effected directly at once, or indirectly by secondary causes, the perfection of the adaptation is alone sufficient to prove that it must have been effected by Infinite Wisdom. We ought not to feel greatly surprised, nor need our self-esteem be deeply wounded, if long-observant, reflective, and reverent men suggest that we have hitherto misapprehended the modus operandi of the Great Artificer. Instead of wondering that man's views of. the Universe are so incomplete, the wonder is that they penetrate so far, and in many cases apprehend with such clearness and certainty.
We see beautiful coadaptations plainly, in such a creature as the woodpecker, with its feet, tail, beak, and tongue, so admirably fitted to catch [176/177] insects under the bark of trees; we see them in the case of the mistletoe, which draws its nourishment from certain trees, which has seeds that must be transported by certain birds, and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other; we see them, only a little less plainly, in the humblest parasite which clings to the hairs of a quadruped or the feathers of a bird; in the structure of the beetle which dives through the water; in the plumed seed which is wafted by the gentlest breeze; in short, we see beautiful adaptations everywhere and in every part of the organic world.
How, asks Mr. Darwin, to whose theoretical views we purpose to recur hereafter — how have all these exquisite adaptations of one part of the organisation to another part, and to the conditions of life, and of one distinct organic being to another, been perfected? He answers, they are so perfected by what he terms Natural Selection — the better chance which a better organised creature has of surviving its fellows — so termed in order to mark its relation to Man's power of selection. Man, by selection in the breeds of his domestic animals and the seedlings of his horticultural productions, can certainly effect great results, and can adapt organic beings to his own uses, through the accumulation of slight but useful variations given to him by the hand of Nature. But Natural Selection is a power incessantly ready for action, and is as immeasurably superior to man's feeble efforts, as the works of Nature are to those of Art. Natural Selection, therefore, according to Mr. Darwin — not independent creations — is the method through which the Author of Nature has elaborated the providential fitness of His works to themselves and to all surrounding circumstances.
That creatures so remote in the scale of being as plants and animals are still bound together by a web of complex relations, he proves by a curious illustration. Humble-bees are indispensable to the fertilisation of the heartsease, for other bees do not visit that flower. From experiments, he also found that the visits of bees are necessary to the fertilisation of some kinds of clover; but humble-bees alone visit the red clover, as other bees cannot reach the nectar. Hence he concludes that if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare, or wholly disappear. The number of humble- bees in any district depends in a great degree on the number of field-mice, which destroy their combs and nests; and Mr. H. Newman, who has long attended to the habits of humble-bees, believes that "more than two-thirds of them are thus destroyed all over England." Now, the number of mice is largely dependent, as every one knows, on the number of cats; and Mr. Newman says, " Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice." Hence it is quite credible that the presence of a feline animal in large numbers in a district, might determine, through the intervention, first of mice and then of bees, the frequency of certain flowers in that district!
Equally curious, and more difficult to explain, are what are called representative species. Thus we have our British song-thrush, which lines its nest with mud, and which is represented in South America by a thrush which also lines its nest with mud, in the same peculiar manner as our own. This may be called a representation at different points of space; but species are also represented at different epochs of time on the same point of space. Australia, which abounds in kangaroos and other marsupial animals, also contains abundant relics of fossil and extinct kangaroos. New Zealand possesses living wingless birds which are represented by fossil remains of the wingless birds of epochs removed from the present by an unimaginable distance of time.
For, of the elaboration of species as maintained by Mr. Darwin, not the least overwhelming idea is the lapse of time which it has occupied to accomplish. Some species have retained the same specific form for very long periods — enormously long as measured by years. The lapse of time has been so great as to be utterly inappreciable by the human intellect. The mind cannot possibly grasp the full meaning of the term of a hundred million years; and therefore it has a difficulty in adding up and perceiving the full effects of many slight variations, accumulated during an almost infinite number of generations. The belief that species were immutable productions, was almost unavoidable, as long as the history of the world was thought to be of short duration. From geology we have now acquired some idea of the lapse of time. During the early periods of the earth's history, when the forms of life were probably few and simple, the rate of change was probably slow; at the first dawn of life, when very few forms of the simplest structure existed, the rate of change may have been slow in an extreme degree. The whole history of the world, as at present known, although of a length quite incomprehensible to us, will hereafter be recognised as a mere fragment of time, compared with the ages which have elapsed since the first creature, the progenitor of innumerable extinct and living descendants, was created.
From the imperfect and contradictory way in which the past history of the species of organised life on our planet has been interpreted, some notion may be formed of the difficulty of anticipating the future. All that we can with safety presume is, that changes among the living tenants of the earth, equally important in respect to forms and habits with those which have already occurred, are probable in times to come. Some writers believe that man has, at last, "begun to reap the fruits of his tedious education, and has proved to how great a degree 'knowledge is [177/178] power': that he has now acquired a dominion over the material world, and a consequent facility of increase, so as to render it probable that the whole surface of the earth may soon be over-run by this engrossing anomaly, to the annihilation of every wonderful and beautiful variety of animated existence which does not administer to his wants." They apprehend that the multiplication and spread of the human race will have the effect of exterminating whole species and genera of wild animals, and perhaps of plants. It may so turn out, to some extent. The bustard and the wild turkey may, perhaps, one day be laid low in the same grave of extinction which has swallowed up the dodo. With railways invading Africa and Asia, it is not difficult to hear in imagination the funeral knell of the last wild elephant, rhinoceros, giraffe. Insular animals are exposed to extermination by the increase of population and agriculture, as happened with the wolves of England, the capercali of Scotland, the Nestor parrot of Norfolk Island, the aboriginal black man of Van Diemen's Land; but for continental faunae a source of safety and a door of escape exist in the instincts and propensities of man himself.
Man's power of increase and the exercise of his tyranny over the wide-spread earth, are greatly checked by his gregarious tendencies. The crowds who continually stream into great cities and die there childless, are so many petty tyrants, who abdicate their share of territory in the land in favour of its natural brute occupants. If the entire populations of Paris, Berlin, Vienna, and every other great European city, were uniformly dispersed over Europe, each family located on an equal area, and living on the produce of the culture of that area — which might be the case, if men were solitary instead of gregarious in their habits — in twenty years only there must take place a perceptible diminution in the numbers of wild animals, birds, and even insects. But the great surplus of the rural population is drawn off by the temptations of town, leaving the field clear for the occupancy of brutes in default of the occupancy of men.
War is a more efficient institution for the preservation of the ferae naturae than at first sight appears. The chase may be the best school for war; but war both gives full employment to the sportsman, and also diminishes his numbers. While the cat is away, the mice will play, and increase and multiply. Our battles, whether on a grand scale or in single combat, ought to be hailed, by our four-footed and our winged game and vermin, as most auspicious events. When hostile armies prepare to meet in deadly shock, the crows and ravens overhead caw and croak their approval; the rat in the hedgerow squeaks his congratulations to the fox in the brake; the bear in the pine-wood growls his deep satisfaction to the exulting chamois on the Alpine cliff. Can it be doubted that the Indian mutiny and its suppression, respited the lives of sundry tigers, lions, wild swine, and jungle-fowl, affording them a long truce for the undisturbed rearing of numerous litters and broods? It is evident enough, that not many wild races of animals are likely to become extinct until wars shall have utterly ceased; and when that is likely to happen, we may learn by private inquiry of various European potentates, with a further reference to the powers of the western hemisphere.
[An anonymous review of Charles Darwin's On Origin of Species, published on 24 November 1859]: All the Year Round, Volume 3 (1860): pp. 293-99.
IT is well for Mr. Charles Darwin, and a comfort to his friends, that he is living now, instead of having lived in the sixteenth century; it is even well that he is a British subject, and not a native of Austria, Naples, or Rome. Men have been kept for long years in durance, and even put to the rack and the stake, for the commission of offences minor to the publication of ideas less in opposition to the notions held by the powers that be.
But we have come upon more tolerant times. If a man can calmly support his heresy by reasons, the heresy will be listened to; and, in the end, will be either received or refuted, or simply neglected and forgotten. Mr. Darwin also enjoys the benefit of the bygone heresies of previous heretics; one heresy prepares the way for, and weakens the shock occasioned by, another. Astronomical and geological innovations render possible the acceptance of doctrines that would have made people's hair stand on end three centuries ago. This is an enormous progress; for what are three or four centuries in the history of the human race? What, in the history of the world? Truth is a bugbear which is fast losing its terrors: we are getting more and more accustomed to it, and are less and less afraid to [293/294] look it in the face. But then comes the old question, "What is Truth?" Mr. Darwin believes he knows, or is on the way to know.
Charles Darwin comes of a family renowned for close observation, intellectual ability, and boldness of speculation; he is gifted with clear and passionless judgment, and with an amiable and gentlemanly disposition; it is doubtful whether he have an enemy in the world; it is certain that he has, and deserves to have, many friends. He is blessed with a sufficiency of worldly riches, and has not strong health — the very combination to make a student. He is sincerity itself, thoroughly believing all he states, and daring to state what he believes. No mental reservation is employed to dissemble the tendency of his scientific views. He has circumnavigated the globe, and beheld the manners of many men, savage and civilised; of many birds, beasts, reptiles, and fishes. He has compared living forms with those which existed on the same spot of land ages and ages ago. In his Voyage with the Beagle he has delighted his readers with the simplicity and the clearness with which he has explained geological changes. For more than twenty years he has been patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on the origin of living things as we now behold them existing; regardless of expense and labour, he has long searched for the truth respecting this question. He believes he has found it, and he enunciates his creed in a book which is an abstract of a larger work that will take two or three more years to complete.
But, as the tolerant spirit of the age allows him to state and to hold his belief unmolested, it also allows dissenters from his novel doctrines to declare their unbelief of them, and to manifest the hardness of their hearts by utter deafness to Mr. Darwin's most persuasive attempts at conversion. The world in general is quite unprepared to hear his unaccustomed views propounded. The propositions are so unfamiliar, that, be they false or be they true, they are almost sure to meet with a flat denial. The dominant and fundamental idea may be grand, clear, and decided. As a theory, it is complete and harmonious in all its parts, regarded merely as a theory; but, as a history of the past, and as a statement of present and future facts, its authority must entirely rest on the reader's judgment whether the proofs and the reasoning are conclusive to his mind or not. It is a question of the interpretation to be given to certain appearances and occurrences; it is a matter of circumstantial evidence. Mr. Darwin is already supported by a small party of disciples and fellow-labourers, who put faith in his inspiration; while the great majority shrink back in alarm at the boldness of his conclusions, and at the illimitable lapse of time which it unfolds before their wondering and bewildered gaze. He will hardly be surprised himself — nor will the reader — to find that the mass of his audience have ears but hear not, and eyes but see not — as he sees and understands the works of nature. Before accepting such a theory, we, the multitude, must think twice. Well, let us think twice; thinking twice never does harm.
The creed to which it is proposed to convert the world is as follows: Although much remains obscure, and will long remain obscure, Mr. Darwin entertains no doubt that the view which most naturalists entertain, and which he formerly entertained himself — namely, that each species has been independently created — is erroneous. He is fully convinced that species are not immutable;* [* See "Species," in All the Year Round, No. 58, p. 174.] but that those belonging to what are called the same genera are lineal descendants of some other and generally extinct species.
The modifications which species have undergone are mainly, but not exclusively, he believes, the result of a process called Natural Selection. He cannot doubt that the theory of descent, with modification, embraces all the members of the same class. He believes that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number. Analogy would lead him one step further; namely, to the belief that, in the beginning, there arose some single, primitive, rudimentary, organised cell, or elementary being, which was the first parent of every living creature — that all animals and plants have descended from some one prototype. But analogy, he owns, may be a deceitful guide. Nevertheless, all living things have much in common in their chemical composition, their germinal vesicles, their cellular structure, and their laws of growth and reproduction. We see this even in so trifling a circumstance as that the same poison often similarly affects plants and animals; or that the poison secreted by the gall-fly produces monstrous growths on the wild rose or oak-tree. Therefore, Mr. Darwin would infer from analogy that, probably, all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed by the Creator.
Is it too much to say that, in the good old times, opinions like these would have been strongly redolent of fagot and flame?
Our philosophical reformer adduces numerous facts which he holds to be inexplicable on the theory of independent acts of creation. By the supposition of a migration, with subsequent modification, we can see why oceanic islands should be inhabited by few species, but, of these, that many should be peculiar. We can clearly see why those animals which cannot cross wide spaces of ocean, as frogs and terrestrial mammals, should not inhabit oceanic islands; and why, on the other hand, new and peculiar species of bats, which can traverse the ocean, should so often be found on islands far distant from any continent. The grand facts respecting the grouping of all organic beings on certain areas of the earth's surface — such as a predominance of monkeys with prehensile tails in one country, of ant-eaters and toothless animals in [294/295] another, of pouched animals in another, of a peculiar modification of leaves in Australian shrubs, of peculiar aloes or agaves in America — are inexplicable on the theory of creation.
Glancing at instincts, marvellous as some are, they offer, it appears, no greater difficulty than does corporeal structure, on the theory of the Natural Selection of successive, slight, but profitable, modifications. We can thus understand why nature moves by graduated steps in endowing different animals of the same class with their several instincts. On the view of all the species of the same genus having descended from a common parent, and having inherited much in common, we can understand how it is that allied species, when placed under considerably different conditions of life, yet should follow nearly the same instincts; why the male wrens of North America, for instance, build "cock-nests" to roost in, like the males of our distinct kitty-wrens — a habit wholly unlike that of any other known bird. On the view of instincts having been slowly acquired through Natural Selection, we need not marvel at some instincts being apparently not perfect, but liable to mistakes, as when blow-flies lay their eggs in the carrion-scented flowers of stapelias; nor at many instincts causing other animals to suffer, as when ants make slaves of their fellow-ants, when the larvae of ichneumon flies feed within the live bodies of caterpillars, and when the nestling cuckoo ungratefully ejects his legitimate foster-brethren out of the family nest.
Instincts are as important as bodily structure for the welfare of each species, under the conditions of life by which it happens to be surrounded. Under changed circumstances, it is possible that slight modifications of instinct might be profitable to a species; and if it can be shown that instincts do vary ever so little, then Mr. Darwin sees no difficulty in Natural Selection preserving and continually accumulating variations of instinct to any extent that may be profitable. His line of argument — and the whole volume is one long argument — may be summed up in this: give him an inch, and he takes an ell. Instincts certainly do vary — for instance, the migratory instinct varies, both in extent and direction, and in its total loss. So it is with the nests of birds, which vary partly in dependence on the situations chosen and on the nature and temperature of the country inhabited, but often from causes wholly unknown to us. It is thus, he believes, that all the most complex and wonderful instincts have originated; although no complex instinct can possibly be produced except by the slow and gradual accumulation of numerous slight, yet profitable, variations, requiring ages upon ages, and tens of thousands, perhaps hundreds of millions, of generations to work them out. For Mr. Darwin assumes such an inconceivably vast period of lapsed time for the accomplishment of his theory, that it is simply not eternity, because it hadbeginning.
Variations of instinct, thus acquired, become, in races, habitual and hereditary. Habit and the selection of so-called accidental variations, have played important parts in modifying the mental qualities of our domestic animals. It cannot be doubted that young pointers will sometimes point, and even back other dogs, the very first time that they are taken out; retrieving is certainly in some degree inherited by retrievers; as is a tendency to run round, instead of at, a flock of sheep by shepherds' dogs. These actions do not differ essentially from true instincts; for the young pointer can no more know that he points to aid his master, than the white butterfly knows why she lays her eggs on the leaf of the cabbage. How strongly these habits and dispositions are inherited, and how curiously they become mingled, is well shown when different breeds of dogs are crossed. A cross with the greyhound has given to a whole family of shepherds' dogs, the lurchers, a tendency to hunt hares, rendering them invaluable to poachers. Le Roy describes a dog whose great-grandfather was a wolf, and this dog showed a trace of its wild parentage only in one way — by not coming in a straight line to his master when called.
To understand how instincts in a state of nature have become modified by Natural Selection, let us consider the case of the cuckoo. It is commonly admitted that the more immediate and final cause of the cuckoo's instinct is that she lays her eggs, not daily, but at intervals of two or three days; so that, if she were to make her own nest and sit on her own eggs, those first laid would have to be left for some time unincubated, or there would be eggs, and young birds of different ages in the same nest; which would make the process of laying, hatching, and rearing the young, inconveniently long and troublesome. The American cuckoo makes her own nest, and has eggs and young successively hatched, all at the same time.
Now, instances can be given of various birds which have been known occasionally to lay their eggs in other birds' nests. Let us suppose that the ancient progenitor of our European cuckoo had the habits of the American cuckoo, but that she occasionally laid an egg in another bird's nest by way of experiment. If the old bird profited by this occasional habit, or if the young were made more vigorous by the mistaken maternal instinct of another bird than by their own mother's care, encumbered as she can hardly fail to be by having eggs and young of different ages at the same time, then the old birds, or the fostered young, would gain an advantage. And analogy leads Mr. Darwin to believe that the young thus reared would be apt to follow, by inheritance, the occasional and aberrant habit of their mother, and in their turn would possibly lay their eggs in other birds' nests, and thus be successful in rearing their young. By a continued process of this nature, he believes that the strange instinct of our cuckoo could be, and has been, generated.
To Mr. Darwin, this explanation appears conclusive; other persons, less under the influence of a fixed idea, may observe that, with the help [295/296] of an "if" and a "suppose," there is little difficulty in explaining anything.
The occasional habit of birds laying their eggs in other birds' nests, either of the same or of a distinct species, is not very uncommon with the Gallinaceae; it is frequent with domestic hens; and this, perhaps, explains the origin of a singular instinct in the allied group of ostriches, for several hen ostriches, at least in the case of the American species, unite and lay, first a few eggs in one nest, and then the rest in another, and these are hatched by the males. This instinct may probably be accounted for by the fact of the hens laying a large number of eggs, but, as in the case of the cuckoo, at intervals of two or three days. The instinct, however, of the American ostrich has not as yet been perfected; for a surprising number of eggs lie strewed over the plains, so that in one day's hunting Mr. Darwin himself picked up no less than twenty lost and wasted eggs.
Many bees are parasitic, and always lay their eggs in the nests of bees of other kinds. This case is more remarkable than that of the cuckoo, for these bees have not only their instincts, but their structure also, modified in accordance with their parasitic habits: they do not possess the pollen-collecting apparatus which would be necessary if they had to store food for their own young. Some species likewise of Sphegidae (wasp-like insects) are parasitic on other species; and M. Fabre has lately shown good reason for believing that although the Tachytes nigia generally makes its own burrow and stores it with paralysed prey for its own larvae to feed on, yet that when this insect finds a burrow already made and stored by another sphex, it takes advantage of the prize, and becomes, for the occasion, parasitic. In this case, as with the supposed case of the cuckoo, Mr. Darwin can see no difficulty in Natural Selection making an occasional habit permanent, if, advantage to the species, and if the insect whose nest and stored food are thus feloniously appropriated, be not thus exterminated.
Such ideas are opposed to the belief of philosophers who hold that the various species of plants and animals have been independently created, and have been purposely fitted and adapted to the place in creation which they were intended to occupy by an Overruling Intelligence; for it is maintained that the more complex organs and instincts have been perfected, not at once in the first-created individual, by the Hand of the Maker, but by the accumulation of innumerable slight variations, each good for the individual possessor for the time being, during an exceedingly long succession of individuals from generation to generation.
The result is asserted to have been effected in this way: there can be no doubt that species give rise to minor varieties; for no two individuals are exactly alike, but may be easily distinguished one from the other. A shepherd knows every sheep in his flock, a huntsman every hound in his pack, calling it by name; a busy- body knows every face in his village and its neighbourhood; probably a bee knows every bee belonging to its hive. Variations are often hereditary; red-haired parents will probably have a red-haired family. Varieties of talent and bodily strength are hereditary; diseases and defects are hereditary, as is every day seen with consumption and deafness. If any animal or plant in a state of nature be highly useful to man, or from any cause closely attract his attention, varieties of it will almost universally be found recorded. Now, individual differences are considered by Mr. Darwin as the first step towards such slight varieties as are barely thought worth mentioning in works on natural history: varieties which are in any degree more distinct and permanent, are steps leading to more strongly marked and more permanent varieties; and these latter lead to sub-species, and to species. In short, all organised and animated forms are in a state of passage from one stage of difference to another; all nature is moving insensibly forwards up the slope of one vast sliding scale; the world is a never-ceasing workshop for the process of manufacturing new species of plants and animals.
Mr. Darwin believes that any well-marked variety may be called an incipient species; and herein lies the whole turning-point, the cornerstone, perhaps the stumbling-block, of his System of Nature; grant him that, and nothing can stop the career of his theory; give him that inch, and he may take, not an ell, but a hundred thousand miles of philosophical territory. Conscious of the importance of his postulate, he candidly observes: " Whether this belief" (that varieties are incipient species) " be justifiable, must be judged of by the general weight of the several facts and views given throughout this work." Achilles is a mighty man, but unfortunately he is afflicted with a vulnerable heel. Elsewhere he says: " It has often been asserted, but the assertion is quite incapable of proof, that the amount of variation under nature is a strictly limited quantity." But there's the rub. A mathematical demonstration may be impossible; but certain observers and experimenters say that their experiments and observations strongly tend to the belief that varieties do not vary beyond certain limits; that is the impression which their minds receive from what they see; just as Mr. Darwin's observations strongly tend to make him view all existing beings, not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, and to conclude thence that (as all the living forms of life are the lineal descendants of those which lived long before the Silurian epoch) we may feel certain that the ordinary succession by generation has never once been broken, that no cataclysm has desolated the whole world, and that we may look with some confidence to a secure future of equally inappreciable length.
But no human intellect, unaided by revelation, is at present able to make such conclusions as these matters either of positive proof or of positive refutation. They must remain a question [296/297] of opinion, a balancing of probabilities, in which each man judges according to his lights, the tone of his mind, and the inferences which his previous notions lead him to draw from the premises before him. Two men may arrive at contrary opinions, both reasoning with perfect sincerity of heart and desire for truth, For instance, while Mr. Darwin holds that the world has been desolated by no past cataclysm and need apprehend no future one (which is contrary to the universal tradition and belief of civilised nations), M. Boutigny, a savant, of high rank in his own country, asserts, with specious and plausible argument, not only that the moon was shot out by a convulsive explosion from the earth, but that our planet may any day be seized with the throes of a universal earthquake which shall end in the expulsion of a second satellite; in which case, every living thing must be destroyed by fire. No cataclysm! Why Messieurs Adhémar and Lehon, distinguished men of science, believe that they have proved that a grand deluge must inevitably devastate the globe every ten thousand five hundred years* [* See All the Year Round, No. 52, p. 40.]; that such deluges have regularly occurred during all previous time, and that such will recur again at their stated epochs; and that, although these grand deluges may not be so universal as to desolate the whole world, they are cataclysms sufficiently terrific to exterminate the great majority of existing creatures, and to render a fresh act of creation an event at least desirable and called for by circumstances.
To return to the theory by which independent creations are obviated. Nature is most prodigal in conferring life. More individuals of every kind, both plants and animals, are produced than can possibly survive, and there must in every case be a contest for life; either between individuals of the same species, or between the individuals of distinct species. It is Malthus's doctrine applied to the whole animal and vegetable kingdoms, with increased force; for, in this case, there can be no artificial increase of food, and no prudential restraint from marriage. Although some species may be now increasing more or less rapidly in numbers, all cannot so increase, for the world would not hold them. There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair. Even slow-breeding man has doubled in twenty-five years; and at this rate, in a few thousand years there would literally not be standing-room for his progeny. Linnaeus has calculated that if an annual plant produced only two seeds — and there is no plant so unproductive as this — and their seedlings next year produced two, and so on, then, in twenty years, there would be a million of plants.
As a consequence, the weakest goes to the wall; it is a race for life, with the deuce taking the hindmost. A grain in the balance will determine which individual shall live and which shall die: which variety or species shall increase in number, and which shall decrease, or finally become extinct. The slightest advantage in one being, at any age or during any season, over those with which it comes into competition, or any better adaptation in however slight a degree to the surrounding physical conditions, will tend to the preservation of that individual, and will generally be inherited by its offspring. The offspring, also, will thus have a better chance of surviving, for, of the many individuals of any species which are periodically born, but a small number can survive. This is Natural Selection — a power which acts during long ages, rigidly scrutinising the whole constitution, structure, and habits of each creature — favouring the good and rejecting the bad. Though nature grants vast periods of time for the work of natural selection, she does not grant an indefinite period; for as all organic beings are striving, it may be said, to seize on each place in the economy of nature, if any one species does not become modified and improved in a corresponding degree with its competitors, it will soon be exterminated.
Cases of adaptation which have hitherto been attributed to design and contrivance are by this theory regarded as the result of natural selection only. When we see leaf-eating insects green, and bark-feeders mottled grey, the Alpine ptarmigan white in winter, the red grouse the colour of heather, and the black grouse that of peaty earth, we must believe that those tints are of service to these birds and insects in preserving them from danger. Grouse, if not destroyed at some period of their lives, would increase in countless numbers — they are known to suffer largely from birds of prey; and hawks are guided by eyesight to their prey — so much so, that on parts of the Continent persons are warned not to keep white pigeons, as being the most liable to destruction. Hence Mr. Darwin can see no reason to doubt that Natural Selection might be effective in giving the proper colour to each kind of grouse, and in keeping that colour, when once acquired, true and constant.
To make it clear how Natural Selection acts, an imaginary illustration is given. Let us take the case of a wolf, which preys on various animals, securing some by craft, some by strength, and some by fleetness; and let us suppose that the fleetest prey, a deer, for instance, had from any change in the country increased in numbers, or that other prey had decreased in numbers, during that season of the year when the wolf is hardest pressed for food. Under such circumstances, there is no reason to doubt that the swiftest and slimmest wolves would have the best chance of surviving, and so be preserved or selected — provided always that they retained strength to master their prey at this or some other period of the year, when they might be compelled to prey on other animals. There seems no more reason to doubt this, than that man can improve the fleetness of his greyhounds by methodical selection, or by that unconscious selection which results from [297/298] each man trying to keep the best dogs without any thought of modifying the breed.
Even, without any change in the proportional numbers of the animals on which our wolf preyed, a cub might be born with an innate tendency to pursue certain kinds of prey. Nor can this be thought very improbable; for we often observe great differences in the natural tendencies of our domestic animals; one cat, for instance, taking to catching rats, another mice; one cat, according to Mr. St. John, bringing home winged game, another hares, or rabbits, and another hunting on marshy ground and almost nightly catching woodcocks or snipes. The tendency to catch rats rather than mice is known to be inherited. Now, if any slight innate change of habit or of structure benefited an individual wolf, it would have the best chance of surviving and of leaving offspring. Some of its young would probably inherit the same habits or structure, and by the repetition of this process, a new variety might be formed which would either supplant or coexist with the parent form of wolf. Or, again, the wolves inhabiting a mountainous district, and those frequenting the lowlands, would naturally be forced to hunt different prey; and from the continued preservation of the individuals best fitted for the two sites, two varieties might be slowly formed. According to Mr. Pierce, there are two varieties of the wolf inhabiting the Catskill Mountains in the United States; one with a light greyhound-like form, which pursues deer, and the other more bulky, with shorter legs, which more frequently attacks the shepherds' flocks.
The use and the disuse of particular organs combine their effects with those of natural selection, in the modification of species; use strengthens and enlarges certain parts, and disuse diminishes them. Such modifications are inherited. Many animals have structures which can be explained by the effects of disuse. As Professor Owen has remarked, there is no greater anomaly in nature than a bird that cannot fly; yet there are several in this state. Since the larger ground-feeding birds seldom take flight except to escape danger, Mr. Darwin believes that the nearly wingless condition of several birds, which now inhabit or have lately inhabited several oceanic islands, tenanted by no beast of prey, has been caused by disuse. The ostrich, indeed, inhabits continents, and is exposed to danger from which it cannot escape by flight; but by kicking it can defend itself from its enemies, as well as any of the smaller quadrupeds. We may imagine that the early progenitor of the ostrich had habits like those of a bustard, and that as Natural Selection increased in successive generations the size and weight of its body, its legs were used more, and its wings less, until they became incapable of flight.
The eyes of moles and of some burrowing rodents are rudimentary in size, and in some cases are quite covered up by skin and fur. This state of the eyes is probably due to gradual reduction from disuse, but aided, perhaps, by Natural Selection. In South America, a burrowing rodent, the tuco-tuco, is even more subterranean in its habits than the mole; and the Spaniards, who often catch them, assert that they are frequently blind. One, which Mr. Darwin kept alive, was certainly in this condition, the cause, as appeared on dissection, having been inflammation of the nictitating membrane. As frequent inflammation of the eyes must be injurious to any animal, and as eyes are certainly not indispensable to animals with subterranean habits, a reduction in their size, with the adhesion of the eyelids and growth of fur over them, might, in such case, be an advantage; and if so, Natural Selection would constantly aid the effects of disuse. It is well known that several animals, belonging to the most different classes, which inhabit the caves of Styria and of Kentucky, are blind. In some of the crabs, the foot-stalk for the eye remains, though the eye is gone; the stand for the telescope is there, though the telescope with its glasses has been lost. As it is difficult to imagine that eyes, though useless, could be in any way injurious to animals living in darkness, Mr. Darwin attributes their loss wholly to disuse. Not a single domestic animal can be named which has not, in some country, drooping ears; and the view suggested by some authors, that the drooping is due to the disuse of the muscles of the ear from the animals not being much alarmed by danger, is accepted as probable.
Mr. Wollaston has discovered the remarkable fact that two hundred kinds of beetles, out of the five hundred and fifty inhabiting Madeira, cannot fly; and that of the twenty-nine endemic genera, no less than twenty-three genera have all their species in this condition. Several facts, namely, that beetles, in many parts of the world, are frequently blown to sea and perish; that the beetles in Madeira, as observed by Mr. Wollaston, lie much concealed until the wind lulls and the sun shines; that the proportion of wingless beetles is larger on the exposed Desertas than in Madeira itself; and especially the extraordinary fact, so strongly insisted on by Mr. Wollaston, of the almost entire absence of certain large groups of beetles, elsewhere excessively numerous, and which groups have habits of life almost necessitating frequent flight;—these several considerations have made Mr. Darwin believe that the wingless condition of so many Madeira beetles is due mainly to the action of natural selection, but combined probably with disuse. For, during thousands of successive generations, each individual beetle which flew least, either from its wings having been ever so little less perfectly developed, or from indolent habit, will have had the best chance of surviving from not being blown out to sea; and, on the other hand, those beetles which most readily took to flight would oftenest have been blown to sea and thus have been destroyed. As with mariners shipwrecked near a coast, it would have been better for the good swimmers if they had been able to swim still further, whereas it would have been better for [298/299] the bad swimmers if they had not been able to swim at all, and had stuck to the wreck.
The theory, of which a brief sample has been given, entails the vastest consequences. We are no longer to look at an organic being as a savage looks at a ship — as at something wholly beyond his comprehension; we are to regard every production of nature as one which has had a history; we are to contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, nearly in the same way as when we look at any great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders, of numerous workmen. The natural system of classification becomes a genealogical arrangement, in which we have to discover the lines of descent by the most permanent characters, however slight their vital importance may be; because the real affinities of all organic beings are due to inheritance or community of descent. Natural Selection can only act through and for the good of each being; acting by competition, it adapts the inhabitants of each country only in relation to the degree of perfection of their associates; so that we need feel no surprise at the inhabitants of any one country (although on the ordinary view supposed to have been specially created and adapted for that country) being beaten and supplanted by the naturalised productions from another land. Nor ought we to marvel if all the contrivances in nature be not, as far as we can judge, absolutely perfect; and if some of them be abhorrent to our ideas of fitness. We need not marvel at the sting of the bee causing the bee's own death; at the instinctive hatred of the queen bee for her own fertile daughters; and at other such cases.
Judging from the past, we are to infer that not one living species will transmit its unaltered likeness to a distant futurity. And, of the species now living, very few will transmit progeny of any kind to a far-distant futurity; for the manner in which all organic beings are grouped, shows that the greater number of species of each genus, and all the species of many genera, have left no descendants, but have become utterly extinct. We can so far take a prophetic glance into futurity as to foretell that it will be the common and widely-spread species, belonging to the larger and dominant groups, which will ultimately prevail and procreate new and dominant species. And as Natural Selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.
Timid persons, who purposely cultivate a certain inertia of mind, and who love to cling to their preconceived ideas, fearing to look at such a mighty subject from an unauthorised and unwonted point of view, may be reassured by the reflection that, for theories, as for organised beings, there is also a Natural Selection and a Struggle for Life. The world has seen all sorts of theories rise, have their day, and fall into neglect. Those theories only survive which are based on truth, as far as our intellectual faculties can at present ascertain; such as the Newtonian theory of universal gravitation. If Mr. Darwin's theory be true, nothing can prevent its ultimate and general reception, however much it may pain and shock those to whom it is propounded for the first time. If it be merely a clever hypothesis, an ingenious hallucination, to which a very industrious and able man has devoted the greater and the best part of his life, its failure will be nothing new in the history of science. It will be a Penelope's web, which, though woven with great skill and art, will be ruthlessly unwoven, leaving to some more competent artist the task of putting together a more solid and enduring fabric.
Transmutation of Species [Anonymous Review]
All the Year Round, Volume 3, 98 (9 March 1861): 519-21.
IN the year 1748 — ten years after the death of its learned author — a book was published at Amsterdam, under the title, Telliamed, or Discoveries of an Indian Philosopher with a French Missionary. It had been written by a Frenchman, whose real name was De Maillet, and was dedicated to the author of some imaginary voyages to the sun and moon. The book is in a pleasant style, and discusses several questions of interest in natural history in a manner not a little original and ingenious. The title Telliamed is a mere anagram of the author's name, and certainly the Indian philosopher and the French missionary have very little to do with the subject treated of; but the argument and the book are not much the worse for their anomalies.
Benoit de Maillet was born in 1656 at St. Mihiel on the Meuse, in France, and is described to have passed the first thirty-six years of his life in the country in complete idleness. No doubt during this time the speculative tendency of his mind was nourished, and his powers of observation quickened. The first we hear of his public life is that he was sent to Egypt in 1692, as Consul-General of France, and he evidently applied himself with energy and intelligence to acquire the knowledge needed in so important a post. Ten years afterwards he was appointed ambassador to Abyssinia, but declining to accept an honour which at that time must have involved great risk and hardship, he obtained permission to exchange it for the consulship at Leghorn. After remaining some years in this and in other important occupations, he retired from public life, and, residing at Marseilles, found leisure to prepare and publish a collection of interesting documents concerning Egypt and its inhabitants. His health gave way while pursuing researches and preparing material for other works on physical geography, but he lived to an advanced age, and left behind him the unpublished speculations which were afterwards given to the world under the curious title we have already quoted.
De Maillet, adopting the Neptunian hypothesis, and putting forth the opinion that the earth originally existed as a chaotic mass of mixed earth and water, reduced after a time by evaporation to the division and separation of land from water, which we now know to exist, was inclined to account for this by the theory that the earth is gradually approaching the sun — that it has always been doing so — and will continue to creep nearer and nearer, till its final destruction by conflagration on the last day. With this theory he mixes up another, arguing that as the whole earth was originally covered with water, all animals of every kind must have been originally derived from aqueous parentage. In illustration and support of this view, he mentions as familiarly known, the existence of mermen and mermaids, and other fabulous monsters of antiquity; and associates them with flying fishes, and other real animals, as exhibiting singular analogies with birds and quadrupeds. Bearing in mind these analogies, our author proceeds to insist that the gradual increase of land, owing to the evaporation of the water that at one time covered the earth, could not but be accompanied by a corresponding modification of the animal inhabitants. The animals dwelling in deep water would have to accustom themselves to shallower water. The original tenants of the shallow water would be reduced to adapt themselves, first to absolute shoals and mud banks, and soon to land altogether dry, which never received the wash of the tidal wave; and in order to obtain this adaptation, and retain habits so different from those with which they were created, they must have been endowed with considerable elasticity and adaptability. Thus he considers permanent varieties might be secured, and one species be in the course of time transmuted into another.
The following extract from Telliamed will give some idea both of the author's views and his style in reference to this curious subject:
It may happen, as, indeed, we know it often does happen, that winged or flying fishes, chasing their prey, or being pursued in the sea, carried away by the eager desire either for food or to escape from death, or being, perhaps, impelled by storm-waves, have fallen into swamps or grass, whence they were unable to escape, and that in this state they have acquired a greater capacity for flying. Their fins, no longer bathed in the sea, split and separated in consequence of the drying. Finding in the reedy marshes and swamps sufficient food to sustain them, the rays of their fins separating from each other, would become prolonged and clothed with feathers, or, to speak more correctly, the membranes by which they had before been connected would become metamorphosed. The feathers thus formed would grow, the skin would become covered with down of the colour of the original skin, and the down would grow. The small ventrical fins of a fish would become the feet of a bird; the beak and the neck of some birds would lengthen and of others shorten, and so on, for the rest of the body. But a general conformity would exist with the original structure, and this may always be easily recognised.
Take, for example, the fowls large and small, even those of India, whether crested or not, even those of which the plumage goes the reverse way (from the tail to the head), and you may find similar animals in the sea both scaled and not scaled. All the parrots, whose plumage is so peculiar, and the rarest and most strangely marked birds, resemble fishes, painted like them, in black, brown, grey, yellow, green, red, violet, gold and azure; and this precisely in those parts where the plumage of the same birds is so strangely diversified.*
* Telliamed, tom. ii. p. 166, ed. 1755.
Strange and little founded in natural history knowledge as this argument may seem, it is not wanting in a kind of picturesque ingenuity. The idea clearly is, that an animal placed in new and unexpected conditions which do not [519/520] quite destroy life, adapts its organs, so far as they are adaptable, to the altered circumstances. If there is food at hand, and enemies are not present, the animal will have time to develop any peculiarities favourable to the new conditions that have hitherto lain dormant; and if the change has affected a race, the next generation will be not unlikely to have some individuals modified in a yet more favourable way. We may thus ultimately obtain a permanent variety, which is to all intents and purposes a species. If you are content to take the exposition of M. de Maillet as an illustration pointing to the direction in which a change in the proportions and organs of animals may extend and become permanent, it seems to be absurd and impossible.
The idea of the derivation of one so-called species from another, the two being unlike in what are regarded as essential characters, is necessarily fundamental with all naturalists who are not inclined to admit that new species have been abruptly introduced from time to time upon the earth, to fill up acknowledged gaps in creation, or to take the place of others which have either died out from actual exhaustion and old age, or which are to be driven out by the new arrival.
What is generally understood by a species, is a group of animals or plants having certain peculiarities of structure in common, and from which other like animals or plants are naturally derived. When two individuals, a male and female belonging to two different groups, can be induced to breed together, the result is considered a hybrid, and two such hybrids, if male and female, will rarely breed together and produce young. The horse and the ass producing the mule afford an illustration too obvious to require more than mere mention.
But it must not be forgotten that in many animals, such as dogs, horses, pigeons, and others that are domesticated, there is enormous difference between different breeds or varieties, sometimes amounting to more than the difference between some of the groups we call species. Thus there arises a very important question: What is the essential difference between a species and one of those varieties which, having assumed a certain structure in successive generations, always transmits such structure? This kind of variety is called permanent, to distinguish it from that which is modified in each successive generation. What, then, is the difference between a species and a permanent variety.
If we assume that there is an essential difference, we must suppose that in each case there is some unknown but defined limit beyond which no further change can occur. As difference of size, shape, and colour; difference of bone, muscle, and nerve; difference of habit, instinct, and intelligence; all certainly do occur in the case of permanent varieties, it is very difficult, if not impossible, to say what other differences may not be produced if sufficient time be allowed. If, on the other hand, there be no limit to variety, there can be no such thing as essential difference between species, and one may be derived from another.
But, supposing this possible, in a few simple cases can the law be assumed as general? In other words, if a wolf may originally have been the parent of the whole race of dogs, must we conclude, as De Maillet did, that the merman, if there ever was one, was the original founder of the human race, and the flying-fish the commencement of bird life? Such a monstrous conclusion would require a powerful chain of argument to induce any of us to believe it. Here, then, step in the naturalists, who are unable to believe that species have been introduced by successive isolated acts of creation, since this notion involves a want of continuity and harmony in the great system of nature. They endeavour to illustrate and explain in what way the divergence from an original form, the gradual production of an improved form, or in some cases the reduction to a lower form of organisation, has taken place. De Maillet's idea was indeed vague enough, but not without a fair amount of ingenuity. Lamarck, one of the most celebrated naturalists of modern times, followed out the idea and ripened it into a system and theory. Another theory was put forward, a few years ago, in England, in a very popular book, Vestiges of the Natural History of Creation; and very lately one of our most ingenious and most sound geologists (Mr. Charles Darwin), who is also an excellent naturalist, has advanced a modification of it which is worthy of all consideration. Lamarck's view of the cause of passage of one species into another was as follows. He considered that the production of a new organ in an animal frame is the result of some new want, and that to satisfy this want a new movement was introduced, and an attempt made by the animal to supply the want. Thus an intelligent and strong-willed slug, originally without tentacula or feelers, would tend to push forward the head in advance of the body, until by this effort some approach was made to the existence of such organs. Now, since all peculiarities of structure are transmitted by parents to their offspring, the young of such snail would have rudimentary feelers which it, could develop by similar means into more complete examples. Such is, in a few words, the Lamarckian doctrine of the transmutation of species by gradual derivation and the improvement of individuals. By an exertion of the will, constantly operating, portions of nervous and other animal fluids are supposed to be determined towards particular parts of the body, and the result is the production of an organ such as circumstances require. In the Vestiges, the author supposes that new species are the occasional offspring of others long since established—a view not without attraction when placed in the light prepared for it by the author, and with all his illustrations around it, but hardly bearing interpretation into the every-day language of ordinary existence. [520/521] Mr. Darwin's view is based on a sound knowledge of natural history, not only of recent animals, but of those who have lived in former times, and whose remains, more or less perfect, handed down for our examination, prove the existence of large and complete groups now altogether lost — of many links connecting groups now apparently without any mutual relations — and even of some, the presence of which seems to give additional complication to a problem already almost beyond human power to unravel. The method by which nature has acted, according to Mr. Darwin, is by a natural selection of animals and organs best fitted to struggle against all competitors in the great battle everywhere fighting for food and existence. We see throughout nature a marvellous and exquisite adaptation of each part of all living beings to every other part; and yet, at the same time, there is in all, the utmost sensitiveness to change, and tendency to individual variation. No sooner is existence rendered more or less difficult in any given area, than every inhabitant of the district struggles to escape or take advantage of it. If any have already an organisation adapting them to benefit by it, they will immediately do so, and drive out others; and this struggle goes on as well from the high rate at which all organic beings tend to increase, as from the inevitable and invariable tendency to change. As also there is in every race a struggle to increase and become dominant, so is there also a system of checks keeping it in its proper place.
Variations being incessant, may be either indifferent, advantageous, or injurious. The first would manifestly not be affected by any principle of natural selection, but such selection comes into play for the preservation of the favourable and the rejection and consequent destruction of the unfavourable.
As man, in domesticating animals and plants, and taking advantage of natural power of change for his own purposes, has in so many cases produced a great result in a moderate time, what may not nature throughout all time? Man can act only on external and visible characters, nature cares nothing for appearances, except in so far as they may be useful to any being. She can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life. Man selects only for his own good, nature only for that of the being which she tends. Under nature the slightest difference of structure or constitution may well turn the nicely balanced scale in the struggle for life, and so be preserved. . . . . . . It may be said that natural selection is daily and hourly scrutinising throughout the world every variation, even the slightest, rejecting that which is bad, preserving and adding up all that is good, silently, and insensibly working whenever and wherever opportunity offers at the improvement of each being in relation to its conditions of life.*
* Darwin, On the Origin of Species, pp. 83, 84.
Natural selection entails extinction, and then explains the very important part that extinction of species has acted in the world's history. It also leads inevitably to divergence of character. It is a great and most useful power in nature's hands: or rather, perhaps, it is the simple method of nature in accomplishing all that is required for continuing the great cycle of existence.
The view that seems to be advocated by Professor Owen, in opposition to that of natural selection as illustrated by Mr. Darwin, seems hardly more natural and involves quite as many difficulties. It is not easy to give it in simple language, as it is derived from observations in an obscure and only recently studied department of natural history, and is illustrated by animals little known to the general reader. We believe that he holds the doctrine that changes of surrounding influences, the operation of some intermittent law at long intervals, and other natural causes, may produce a divergence from an original form, and terminate in the formation of a new type. It is certain, however, that he does not bind himself even to this hypothesis: rather suggesting it as less objectionable than as in itself sufficient.
The work commenced by De Maillet is still, then, incomplete, and the mystery of creation has yet to be solved. Whether, indeed, we are much nearer the real solution than when our author wrote, and whether the ideas expressed more definitely are really more clear, is not altogether certain. One thing, however, seems certain: that the fit way to investigate them as so many problems, is to question nature closely, to experiment with nature as far as she grants opportunity, and always to accept fairly and openly the conclusions derived from such investigations. We may not by these means advance very rapidly, but we shall advance surely; and there will be no fear of any check occurring, to interfere with the progress of our labour.
"All the Year Round. Dickens Journals Online." University of Buckingham. Accessed 11 December 2013. http://www.djo.org.uk/
Darwin, Charles. A Naturalist's Voyage Round the World The Voyage Of The Beagle. Project Gutenberg EBook #3704 produced by Sue Asscher. August 6, 2008. The e-version is based on the 1890 11th edition. (The book first appeared in 1839.)
Owen, Richard. "Natural Selection." [Anonymous review of On Origin of Species]. All the Year Round (63), 7 July 1860. Pp. 293-299.
---. "Species." [Anonymous review of On Origin of Species]. All the Year Round (58), 2 June 1860. Pp. 174-178.
---. "Transmutation of Species." [Anonymous review of On Origin of Species]. All the Year Round, (98). 9 March 1861. Pp. 519-521.
Last modified 2 January 2014