AUSTRALIA 795 fauna] jumps from tree to tree ; and the native bear (Phascolarctus), an more than passing interest to the naturalist. The ‘ ‘ mud-fish ” animal with no affinities to the bear, and having a long soft fur and of Queensland {Ceratodus Forsteri) belongs to an ancient order of no tail. More lowly organized than the foregoing are the two fishes—the Dipnoi, only a few species of which have survived monotremes, the Platypus, and Echidna or native porcupine ; the from past geological periods. The Dipnoi show a distinct transiformer is famous for seeming “ half bird, half beast,” and is much tion between fishes and amphibia. For many years only two sought after for its exquisite fur. The dugong lives in the shel- species were known to science : Lepidosiren paradoxa of South tered inlets of the Queensland coast, and is systematically hunted America and Lepidosiren (Protopterus) annectens of Africa. Refor its oil by natives and whites. Three kinds of seals occur cently, however, the Australian mud-fish has been referred to the Dipnoi, —for it was seen that it was provided with a gill-like upon the south coast. The mammals of Australia are with a few exceptions marsupials; breathing apparatus, and also true lungs. The blood circulation that is, they differ profoundly in structure from all other mammals is in a sense intermediate between that of frogs and fishes. The and are lower in the scale of organization. The marsupials of heart has one ventricle and two auricles. So far the mud-fish is Australia have been isolated from the rest of the world from a known only from the Mary and the Burnett rivers. Hardly of period antedating the appearance of higher mammals in other less scientific interest is the Port Jackson shark {Heterodontus). lands. By this isolation they are spared those contests with It is a harmless helmeted ground-shark, living on molluscs, and stronger mammals which resulted in the extermination of the almost the sole survivor of a genus abundant in the Secondary marsupials of other continents, with the exception of the opossums rocks of Europe. One of its remarkable characteristics is the of America. We notice, however, a wonderful development of pavement of crushing teeth with which the mouth is lined. The “ groups,” parallel with the development of the higher mammals beautiful Trigonia shell, so plentiful in Sydney harbour, is another genus originally believed to be extinct. The first descriptions in other lands :— were published from fossil forms. It was a welcome discovery to Marsupials of Australia. Placentals of Europe. find Trigonia still surviving in Australian seas. There are only 1. Rodents. 1. Wombat and allies. about five species living to-day, and even these are not plen2. Carnivora. 2. Native “cats.” tiful. In the Secondary period, however, they must have been 3. Insect-eaters. 3. Bandicoots. extremely abundant; they swarmed in Oolitic seas. 4. Hoofed beasts. 4. Kangaroos. Another link connecting the present fauna of Australia with 5. Sloths and ant-eaters. 5. Native “bear” and echidna. that of Secondary Europe has recently been discovered. For a 6. Mole. 6. Marsupial mole. considerable time a peculiar group of herrings {Diplomystus), characterized by a row of scutes on the back, resembling those found The geographical limits of the marsupials are very interesting. in other types on the opposite aspect of the body, have been The opossums of America are marsupials, though not showing known from Cretaceous and early Tertiary rocks, their range inanomalies as great as kangaroos and bandicoots (in their feet), and cluding Brazil, Wyoming, and the Isle of Wight. Until recently myrmecobius (in the number of teeth). Except the opossums, no these herrings were considered to be extinct, but they have now single living marsupial is known outside the Australian zoological been found alive in certain rivers of New South Wales. region. The forms of life characteristic of India and the Malay The origin of the fauna and flora of Australia has of late attracted peninsula come down to the island of Bali. Bali is separated considerable attention. Much accumulated evidence, biological and from Lombok by a strait not more than 15 miles wide. Yet geological, has pointed to a southern extension of India, an eastern this narrow belt of water is the boundary line between the Austral- extension of South Africa, and a western extension of Australia asian and the Indian regions. The zoological boundary passing into the Indian Ocean. The comparative richness of proteaceous through the Bali Strait is called “Wallace’s line,” after the plants in Western Australia and South Africa first suggested a eminent naturalist who was its discoverer. He showed that not common source for these primitive types. Dr H. 0. Forbes drew only as regards beasts, but also as regards birds, these regions are attention to a certain community amongst birds and other vertethus sharply limited. Australia, he pointed out, has no wood- brates, invertebrates, and amongst plants, on all the lands stretchpeckers and no pheasants, which are widely-spread Indian birds. ing towards the South Pole. A theory was therefore propounded Instead of these it has mould-making turkeys, honey-suckers, that these known types were all derived from a continent which cockatoos, and brush-tongued lozies, all of which are found nowhere has been named Antarctica. The supposed continent extended else in the world. across the South Pole, practically joining Australia and South The Myrmecobius of Western Australia is a bushy-tailed ant- America. Just as we have evidence of a former mild climate in eater about the size of a squirrel, and from its lineage and structure the Arctic regions, so a similar mild climate has been postulated of more than passing interest. It is, Mivart remarks, a survival of for Antarctica. Modern naturalists consider that many of the a very ancient state of things indeed. It had ancestors in a flourish- problems of Australia’s remarkable fauna and flora can be best ing condition during the Secondary epoch. Its congeners even explained by the following hypothesis :—The region now covered then lived in England, as is proved by the fact that their relics by the Antarctic ice-cap was in early Tertiary times favoured by a have been found in the Stonesfield oolitic rocks, the deposition of mild climate ; here lay an Antarctic continent or archipelago. which is separated from that which gave rise to the Paris Tertiary From an area corresponding to what is now South America there strata by an abyss of past time which we cannot venture to express entered a fauna and flora, which, after undergoing modification, even in thousands of years. passed by way of Tasmania to Australia. These immigrants Australia is rich in snakes, and has more than a hundred then developed, with some exceptions, into the present Ausdifferent kinds. Most of these are venomous, but all are not tralian flora and fauna. This theory in the course of a decade equally dreaded. Five rather common species are certainly deadly— has advanced from the position of a disparaged heresy to acceptthe death adder, the brown, the black, the superb, and the tiger ance by leading thinkers. The discovery as fossil, in South snakes. During the colder months these reptiles remain in a America, of primitive or ancestral forms of marsupials has given torpid state. No certain cure has been or is likely to be dis- it much support. One of these, Prothylacinus, is regarded as the covered for their poison, but in less serious cases strychnine has forerunner of the marsupial wolf of Tasmania. An interesting been used with advantage. In tropical waters a sea snake is link between divergent marsupial families, still living in Ecuador, found, which, though very poisonous, rarely bites. Among the the Ccenolestes, is another discovery of recent years. On the inoffensive species are counted the graceful green “tree snake,” Australian side the fact that Tasmania is richest in marsupial which pursues frogs, birds, and lizards, to the topmost branches of types indicates the gate by which they entered. It is not to be the forest; also, several species of pythons, the commonest of supposed that this Antarctic element, to which Professor Tate has which is known as the carpet snake. These great reptiles may applied the name Euronotian, entered a desert barren of all life. attain a length of 10 feet; they feed on small animals, which they Previous to its arrival Australia doubtless possessed considerable crush to death in their folds. In the estuaries of the Northern vegetation and a scanty fauna, chiefly invertebrate. At a comQueensland rivers crocodiles abound. Some aged examples reach a paratively recent date Australia received its third and newest length of 25 feet, and such are most dangerous. A small and constituent. The islands of Torres Strait have been shown to be inoffensive species is found near Port Darwin. Lizards occur in the denuded remnant of a former extension of Cape York peninsula great profusion and variety. A monitor is popularly known as in North Queensland. Previous to the existence of the strait, the “goanna,” a name derived from iguana, an entirely different and across its site, there poured into Australia a wealth of Papuan animal. The “frilled lizard” is a most remarkable creature. forms. Along the Pacific slope of the Queensland Cordillera these When brought to bay it stands erect on its hind-legs, extends an found in soil and climate a congenial home. Among the plants umbrella-like frill around its neck, and at the same time opens the wild banana, pepper, orange, and mangosteen, rhododendron, wide its jaws. The horned lizard of Western Australia {Moloch epiphytic orchids, and the palm ; among mammals the bats and horridus) is reputed the ugliest of existing animals, being covered rats ; among birds the cassowary and rifle birds; and among all over with sharp spines, which give it a vicious and repulsive reptiles the crocodile and tree snakes, characterize this element. appearance; really, however, it is most inoffensive. Frogs of The numerous facts, geological, geographical and biological, which many kinds are plentiful, the brilliant green frogs being especially when linked together lend great support to this theory, have conspicuous and noisy. been well worked out in Australia by Mr Charles Hedley of the Two other creatures may be ranked with myrmecobius, as of Australian Museum, Sydney,
