by Grant Allen
Up to the day, then, when Captain Cook and Sir Joseph Banks, landing for the first time on the coast of New South Wales, saw an animal with short front limbs, huge hind legs, a monstrous tail, and a curious habit of hopping along the ground (called by the natives a kangaroo), the opossums of America were the only pouched mammals known to the European world in any part of the explored continents. Australia, severed from all the rest of the earth — penitus toto orbe divisa — ever since the end of the secondary period, remained as yet, so to speak, in the secondary age so far as its larger life-elements were concerned, and presented to the first comers a certain vague and indefinite picture of what ‘the world before the flood’ must have looked like. Only it was a very remote flood; an antediluvian age separated from our own not by thousands, but by millions, of seasons.
To this rough approximate statement, however, sundry needful qualifications must be made at the very outset. No statement is ever quite correct until you have contradicted in minute detail about two-thirds of it.
In the first place there are a good many modern elements in the indigenous population of Australia; but then they are elements of the stray and casual sort one always finds even in remote oceanic islands. They are waifs wafted by accident from other places. For example, the flora is by no means exclusively an ancient flora, for a considerable number of seeds and fruits and spores of ferns always get blown by the wind, or washed by the sea, or carried on the feet or feathers of birds, from one part of the world to another. In all these various ways, no doubt, modern plants from the Asiatic region have invaded Australia at different times, and altered to some extent the character and aspect of its original native vegetation. Nevertheless, even in the matter of its plants and trees, Australia must still be considered a very old-fashioned and stick-in-the-mud continent. The strange puzzle-monkeys, the quaint-jointed casuarinas (like horsetails grown into big willows), and the park-like forests of blue gum-trees, with their smooth stems robbed of their outer bark, impart a marvellously antiquated and unfamiliar tone to the general appearance of Australian woodland. All these types belong by birth to classes long since extinct in the larger continents. The scrub shows no turfy greensward; grasses, which elsewhere carpet the ground, were almost unknown till introduced from Europe; in the wild lands, bushes, and undershrubs of ancient aspect cover the soil, remarkable for their stiff, dry, wiry foliage, their vertically instead of horizontally flattened leaves, and their general dead blue-green or glaucous colour. Altogether, the vegetation itself, though it contains a few more modern forms than the animal world, is still essentially antique in type, a strange survival from the forgotten flora of the chalk age, the oolite, and even the lias.
Again, to winged animals, such as birds and bats and flying insects, the ocean forms far less of a barrier than it does to quadrupeds, to reptiles, and to fresh-water fishes. Hence Australia has, to some extent, been invaded by later types of birds and other flying creatures, who live on there side by side with the ancient animals of the secondary pattern. Warblers, thrushes, flycatchers, shrikes, and crows must all be comparatively recent immigrants from the Asiatic mainland. Even in this respect, however, the Australian life-region still bears an antiquated and undeveloped aspect. Nowhere else in the world do we find those very oldest types of birds represented by the cassowaries, the emus, and the mooruk of New Britain. The extreme term in this exceedingly ancient set of creature is given us by the wingless bird, the apteryx or kiwi of New Zealand, whose feathers nearly resemble hair, and whose grotesque appearance makes it as much a wonder in its own class as the puzzle-monkey and the casuarina are among forest trees. No feathered creatures so closely approach the lizard-tailed birds of the oolite or the toothed birds of the cretaceous period as do these Australian and New Zealand emus and apteryxes. Again, while many characteristic Oriental families are quite absent, like the vultures, woodpeckers, pheasants and bulbuls, the Australian region has many other fairly ancient birds, found nowhere else on the surface of our modern planet. Such are the so-called brush turkeys and mound builders, the only feathered things that never sit upon their own eggs, but allow them to be hatched, after the fashion of reptiles, by the heat of the sand or of fermenting vegetable matter. The piping crows, the honeysuckers, the lyre-birds, and the more-porks are all peculiar to the Australian region. So are the wonderful and æsthetic bower-birds. Brush-tongued lories, black cockatoos, and gorgeously coloured pigeons, though somewhat less antique, perhaps, in type, give a special character to the bird-life of the country. And in New Guinea, an isolated bit of the same old continent, the birds of paradise, found nowhere else in the whole world, seem to recall some forgotten Eden of the remote past, some golden age of Saturnian splendour. Poetry apart, into which I have dropped for a moment like Mr. Silas Wegg, the birds of paradise are, in fact, gorgeously dressed crows, specially adapted to forest life in a rich fruit-bearing tropical country, where food is abundant and enemies unknown.
Last of all, a certain small number of modern mammals have passed over to Australia at various times by pure chance. They fall into two classes — the rats and mice, who doubtless got transported across on floating logs or balks of timber; and the human importations, including the dog, who came, perhaps on their owners’ canoes, perhaps on the wreck and débris of inundations. Yet even in these cases again, Australia still maintains its proud pre-eminence as the most antiquated and unprogressive of continents. For the Australian black-fellow must have got there a very long time ago indeed; he belongs to an extremely ancient human type, and strikingly recalls in his jaws and skull the Neanderthal savage and other early prehistoric races; while the woolly-headed Tasmanian, a member of a totally distinct human family, and perhaps the very lowest sample of humanity that has survived to modern times, must have crossed over to Tasmania even earlier still, his brethren on the mainland having no doubt been exterminated later on when the stone-age Australian black-fellows first got cast ashore upon the continent inhabited by the yet more barbaric and helpless negrito race. As for the dingo, or Australian wild dog, only half domesticated by the savage natives, he represents a low ancestral dog type, half wolf and half jackal, incapable of the higher canine traits, and with a suspicious, ferocious, glaring eye that betrays at once his uncivilisable tendencies.
Omitting these later importations, however — the modern plants, birds, and human beings — it may be fairly said that Australia is still in its secondary stage, while the rest of the world has reached the tertiary and quaternary periods. Here again, however, a deduction must be made, in order to attain the necessary accuracy. Even in Australia the world never stands still. Though the Australian animals are still at bottom the European and Asiatic animals of the secondary age, they are those animals with a difference. They have undergone an evolution of their own. It has not been the evolution of the great continents; but it has been evolution all the same; slower, more local, narrower, more restricted, yet evolution in the truest sense. One might compare the difference to the difference between the civilisation of Europe and the civilisation of Mexico or Peru. The Mexicans, when Cortez blotted out their indigenous culture, were still, to be sure, in their stone age; but it was a very different stone age from that of the cave-dwellers or mound builders in Britain. Even so, though Australia is still zoologically in the secondary period, it is a secondary period a good deal altered and adapted in detail to meet the wants of special situations.
The oldest types of animals in Australia are the ornithorhynchus and the echidna, the ‘beast with a bill,’ and the ‘porcupine ant-eater’ of popular natural history. These curious creatures, genuine living fossils, occupy in some respects an intermediate place between the mammals on the one hand and the birds and lizards on the other. The echidna has no teeth, and a very bird-like skull and body; the ornithorhynchus has a bill like a duck’s, webbed feet, and a great many quaint anatomical peculiarities which closely ally it to the birds and reptiles. Both, in fact, are early arrested stages in the development of mammals from t
he old common vertebrate ancestor; and they could only have struggled on to our own day in a continent free from the severe competition of the higher types which have since been evolved in Europe and Asia. Even in Australia itself the ornithorhynchus and echidna have had to put up perforce with the lower places in the hierarchy of nature. The first is a burrowing and aquatic creature, specialised in a thousand minute ways for his amphibious life and queer subterranean habits; the second is a spiny hedgehog-like nocturnal prowler, who buries himself in the earth during the day, and lives by night on insects which he licks up greedily with his long ribbon-like tongue. Apart from the specialisations brought about by their necessary adaptation to a particular niche in the economy of life, these two quaint and very ancient animals probably preserve for us in their general structure the features of an extremely early descendant of the common ancestor from whom mammals, birds, and reptiles alike are originally derived.
The ordinary Australian pouched mammals belong to far less ancient types than ornithorhynchus and echidna, but they too are very old in structure, though they have undergone an extraordinary separate evolution to fit them for the most diverse positions in life. Almost every main form of higher mammal (except the biggest ones) has, as it were, its analogue or representative among the marsupial fauna of the Australasian region fitted to fill the same niche in nature. For instance, in the blue gum forests of New South Wales a small animal inhabits the trees, in form and aspect exactly like a flying squirrel. Nobody who was not a structural and anatomical naturalist would ever for a moment dream of doubting its close affinity to the flying squirrels of the American woodlands. It has just the same general outline, just the same bushy tail, just the same rough arrangement of colours, and just the same expanded parachute-like membrane stretching between the fore and hind limbs. Why should this be so? Clearly because both animals have independently adapted themselves to the same mode of life under the same general circumstances. Natural selection, acting upon unlike original types, but in like conditions, has produced in the end very similar results in both cases. Still, when we come to examine the more intimate underlying structure of the two animals, a profound fundamental difference at once exhibits itself. The one is distinctly a true squirrel, a rodent of the rodents, externally adapted to an arboreal existence; the other is equally a true phalanger, a marsupial of the marsupials, which has independently undergone on his own account very much the same adaptation, for very much the same reasons. Just so a dolphin looks externally very like a fish, in head and tail and form and movement; its flippers closely resemble fins; and nothing about it seems to differ very markedly from the outer aspect of a shark or a codfish. But in reality it has no gills and no swim-bladder; it lays no eggs; it does not own one truly fish-like organ. It breathes air, it possesses lungs, it has warm blood, it suckles its young; in heart and brain and nerves and organisation it is a thoroughgoing mammal, with an acquired resemblance to the fishy form, due entirely to mere similarity in place of residence.
Running hastily through the chief marsupial developments, one may say that the wombats are pouched animals who take the place of rabbits or marmots in Europe, and resemble them both in burrowing habits and more or less in shape, which closely approaches the familiar and ungraceful guinea-pig outline. The vulpine phalanger does duty for a fox; the fat and sleepy little dormouse phalanger takes the place of a European dormouse. Both are so ridiculously like the analogous animals of the larger continents that the colonists always call them, in perfect good faith, by the familiar names of the old-country creatures. The koala poses as a small bear; the cuscus answers to the racoons of America. The pouched badgers explain themselves at once by their very name, like the Plyants, the Pinchwifes, the Brainsicks, and the Carelesses of the Restoration comedy. The ‘native rabbit’ of Swan River is a rabbit-like bandicoot; the pouched ant-eater similarly takes the place of the true ant-eaters of other continents. By way of carnivores, the Tasmanian devil is a fierce and savage marsupial analogue of the American wolverine; a smaller species of the same type usurps the name and place of the marten; and the dog-headed Thylacinus is in form and figure precisely like a wolf or a jackal. The pouched weasels are very weasel-like; the kangaroo rats and kangaroo mice run the true rats and mice a close race in every particular. And it is worth notice, in this connection, that the one marsupial family which could compete with higher American life, the opossums, are really, so to speak, the monkey development of the marsupial race. They have opposable thumbs, which make their feet almost into hands; they have prehensile tails, by which they hang from branches in true monkey fashion; they lead an arboreal omnivorous existence; they feed off fruits, birds’ eggs, insects, and roots; and altogether they are just active, cunning, intelligent, tree-haunting marsupial spider-monkeys.
Australia has also one still more ancient denizen than any of these, a living fossil of the very oldest sort, a creature of wholly immemorial and primitive antiquity. The story of its discovery teems with the strangest romance of natural history. To those who could appreciate the facts of the case it was just as curious and just as interesting as though we were now to discover somewhere in an unknown island or an African oasis some surviving mammoth, some belated megatherium, or some gigantic and misshapen liassic saurian. Imagine the extinct animals of the Crystal Palace grounds suddenly appearing to our dazzled eyes in a tropical ramble, and you can faintly conceive the delight and astonishment of naturalists at large when the barramunda first ‘swam into their ken’ in the rivers of Queensland. To be sure, in size and shape this ‘extinct fish,’ still living and grunting quietly in our midst, is comparatively insignificant beside the ‘dragons of the prime’ immortalised in a famous stanza by Tennyson: but, to the true enthusiast, size is nothing; and the barramunda is just as much a marvel and a monster as the Atlantosaurus himself would have been if he had suddenly walked upon the stage of time, dragging fifty feet of lizard-like tail in a train behind him. And this is the plain story of that marvellous discovery of a ‘missing link’ in our own pedigree.
In the oldest secondary rocks of Britain and elsewhere there occur in abundance the teeth of a genus of ganoid fishes known as the Ceratodi. (I apologise for ganoid, though it is not a swear-word). These teeth reappear from time to time in several subsequent formations, but at last slowly die out altogether; and of course all naturalists naturally concluded that the creature to which they belonged had died out also, and was long since numbered with the dodo and the mastodon. The idea that a Ceratodus could still be living, far less that it formed an important link in the development of all the higher animals, could never for a moment have occurred to anybody. As well expect to find a palæolithic man quietly chipping flints on a Pacific atoll, or to discover the ancestor of all horses on the isolated and crag-encircled summit of Roraima, as to unearth a real live Ceratodus from a modern estuary. In 1870, however, Mr. Krefft took away the breath of scientific Europe by informing it that he had found the extinct ganoid swimming about as large as life, and six feet long, without the faintest consciousness of its own scientific importance, in a river in Queensland at the present day. The unsophisticated aborigines knew it as barramunda; the almost equally ignorant white settlers called it with irreverent and unfilial contempt the flat-head. On further examination, however, the despised barramunda proved to be a connecting link of primary rank between the oldest surviving group of fishes and the lowest air-breathing animals like the frogs and salamanders. Though a true fish, it leaves its native streams at night, and sets out on a foraging expedition after vegetable food in the neighbouring woodlands. There it browses on myrtle leaves and grasses, and otherwise behaves itself in a manner wholly unbecoming its piscine antecedents and aquatic education. To fit it for this strange amphibious life, the barramunda has both lungs and gills; it can breathe either air or water at will, or, if it chooses, the two together. Though covered with scales, and most fish-like in outline, it presents points of anatomical resemblance both to salamanders and lizards; and, as a co
nnecting bond between the North American mud-fish on the one hand and the wonderful lepidosiren on the other, it forms a true member of the long series by which the higher animals generally trace their descent from a remote race of marine ancestors. It is very interesting, therefore, to find that this living fossil link between fish and reptiles should have survived only in the fossil continent, Australia. Everywhere else it has long since been beaten out of the field by its own more developed amphibian descendants; in Australia alone it still drags on a lonely existence as the last relic of an otherwise long-forgotten and extinct family.
A VERY OLD MASTER
The work of art which lies before me is old, unquestionably old; a good deal older, in fact, than Archbishop Ussher (who invented all out of his own archiepiscopal head the date commonly assigned for the creation of the world) would by any means have been ready to admit. It is a bas-relief by an old master, considerably more antique in origin than the most archaic gem or intaglio in the Museo Borbonico at Naples, the mildly decorous Louvre in Paris, or the eminently respectable British Museum, which is the glory of our own smoky London in the spectacled eyes of German professors, all put together. When Assyrian sculptors carved in fresh white alabaster the flowing curls of Sennacherib’s hair, just like a modern coachman’s wig, this work of primæval art was already hoary with the rime of ages. When Memphian artists were busy in the morning twilight of time with the towering coiffure of Ramses or Sesostris, this far more ancient relic of plastic handicraft was lying, already fossil and forgotten, beneath the concreted floor of a cave in the Dordogne. If we were to divide the period for which we possess authentic records of man’s abode upon this oblate spheroid into ten epochs — an epoch being a good high-sounding word which doesn’t commit one to any definite chronology in particular — then it is probable that all known art, from the Egyptian onward, would fall into the tenth of the epochs thus loosely demarcated, while my old French bas-relief would fall into the first. To put the date quite succinctly, I should say it was most likely about 244,000 years before the creation of Adam according to Ussher.