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Sir Joseph Hooker, speaking of the relations between the plant-life of the two regions, says : “ Under whatever aspect I regard the flora of Australia and of New Zealand, I find all attempts to theorise on the possible causes of their community of feature frustrated by anomalies in distribution, such as I believe no two other similarly situated countries in the globe present. Everywhere else I recognise a parallelism or harmony in the main common features of contiguous floras, which conveys the impression of their generic affinity at least being affected by migration from centres of dispersion in one of them, or in some adjacent country. In this case it is widely different. Regarding the question from the Australian point of view, it is impossible, in the present state of science, to reconcile the fact of Acacia, Eucalyptus, Casuarina, Callitris, &c., being absent in New Zealand, with any theory of trans-oceanic migration that may be adopted to explain the presence of other Australian plants in New Zealand ; and it is very difficult to conceive of a time or of conditions that could explain these anomalies, except by going back to epochs when the prevalent botanical as well as geographical features of each were widely different from what they are now. On the other hand, if I regard the question from the New Zealand point of view, I find such broad features of resemblance, and so many connecting links that afford irresistible evidence of a close botanical connection, that I cannot abandon the conviction that these great differences will present the least difficulties to whatever theory may explain the whole case.” Thus, whilst there are clear botanical affinities between Australia and New Zealand, these likenesses are really limited to plants which form the characteristic part of the New Zealand flora ; and these plants, for the most part, belong to temperate species.
If the relations between New Zealand and Australia in the matter of their respective Aoras are so intricate, the relations beiween the animal populations of these areas are equally interesting. We may briefly glance, in the first place, at the New Zealand fauna, and then, by way of contrast, concern ourselves more especially with the animal life of Australia. The New Zealand islands, in superficial area, attain a size nearly equal to that of Italy. Their distance from Australia is about 1,200 miles; their vegetation is abundant and well distributed, owing to the absence of desert-lands. The zoology of New Zealand is peculiar. It has no native quadrupeds, if we except a couple of bats; it possesses an almost Hibernian freedom from reptiles in that it has no snakes, only three genera of lizards, and but one frog. There are 34 genera of land birds, and of these
16 are absolutely confined to New Zealand ; and to these are to be added five special genera of aquatic birds, making 21 marked genera in all. Amongst their birds, these islands include the chief species of “wingless" forms. The Moas of New Zealand represent an extinct wingless race, whilst the curious Apteryx(Fig. 4) remains to represent the wingless tribes of to-day. The winged birds include special forms of starlings (Creadion: Heterolocha, exc.); the curious crook-billed plovers (Anarhynchus), which alone of all birds have the bill twisted to the side; and species of swallows, fly-catchers, &c.,
Fig. 4. APTERYX. are also included in the ornithological catalogue of these islands. In New Zealand is found the kakapoe (Stringops habroptilus) or owlparrot, which burrows in the ground, and whose powers of flight have deteriorated; and the curious Notornis, a peculiar genus of rails, likewise possessing short and useless wings, may be lastly mentioned amongst the bird productions of these islands.
Included amongst the few lizards of New Zealand is the famous Hatteria, which in reality forms a connecting link between lizards and crocodiles, and even shows bird-affinities in its ribs. Hatteria thus remains isolated and solitary in its structure amid the lizard-class.
Turning now to Australia itself, we note that land to be the abode of the lower quadrupeds comprised within the two orders Monotremata and Marsupialia, which are represented by the Ornithorhynchus and Echidna, and by the kangaroos (Fig. 5), wombats, phalangers, and allied animals respectively. No monotreme
Fig. 5. KANGAROO. whatever, and no marsupial forms-save the single family of the New World opossum3-exist without the boundaries of Australia. These animals reprezent in
their varied types the orders of higher mammals distributed over the other regions of the earth; and the Australian region thus presents us with the home and head-quarters of the lowest, and, in point of time or geological sequence, the earliest, quadrupeds. Whatever higher quadrupeds—such as the sheep, oxen, horses, etc.-the colonisation of Australia has been the means of introducing into that region, it must be borne in mind that all the native mammals of Australia are of the lower grades, and are, with the exception of the American opossums (which do not occur in Australia), absolutely limited to that region. Even the world-wide rodents, represented here by a few rats and mice, are probably of relatively late introduction.
In respect of its birds, whilst Australia possesses species of the familiar thrushes, warblers, shrikes, crows, &c. of the other regions, it yet exhibits certain peculiar forms of bird-life. The bird-absentees are of themselves typical, for Australia has no representatives of the vultures, pheasants, woodpeckers, barbets, and other birds which are so characteristic of even the Oriental territory. But it has, nevertheless, a rich ornithology of its own, in its birds of paradise, its most typical honey-suckers, its lyre-birds, its scrub-birds, its parroquets, its cockatoos, its mound-birds, and its cassowaries.
These are typically Australian forms; and there are bird-families sparingly found in other parts of the world-such as the swallow-shrikes and flower-peckers—but which are well represented in Australia. Lastly, there are families of birds-such as the kingfishers, pigeons, weaverfinches-well represented in other provinces, and which are, as a rule, better represented in Australia than in other provinces.
The reptiles of Australia do not present any special features for remark. Snakes and lizards are plentiful ; and the Australian amphibians number frogs and toads, but no newts, in their ranks. Thus the Australian region, to sum up, possesses representatives of eighteen families of quadrupeds, eight of these families being absolutely confined to this region. It has seventy-one families of birds, sixteen being peculiar; it possesses four peculiar families out of thirty-one of reptiles; and it has only one family of amphibians, out of a total of eleven, confined within its limits.
Passing now to the western hemisphere, we find the New World divided into the Nearctic and Neotropical Regions (Fig. 1). The former includes North America in its arctic and temperate regions, and is bounded on the south by a line running between Cape Lucas on the west, and the Rio Grande del Norte on the east; the boundary line dipping southwards from this point in a tongue which extends wellnigh to the isthmus of Tehuantepec. Between the life of the Nearctic and Palæarctic Regions there is a striking resemblance. In North American forests, the wolves, lynxes, foxes, bears, elks, deer, beavers, hares, squirrels, pikas, and marmots of Europe are represented often by similar species ; and the bison of Western Europe represents the buffalo of the Nearctic prairies. But North America has its own peculiar quadrupeds likewise. For instance, the skunk and other two genera of weasels are found nowhere but in Nearctic lands. Then there are the carnivorous racoons which are likewise special forms; and among the rodents, the pouched rats (Saccomyida), the jumping mouse, the tree porcupines, and prairie dogs are peculiar. The Insectivora number three peculiar ge nera of moles. The pronghorn antelope (Fig. 6) and the mountain-goat are absolutely Nearctic. The
Fig. 6. PRONGHORN ANTELOPE. opossums complete the list of peculiar mammals of the region; whilst the absentees may be summarised in the remark that the Nearctic Region is chiefly notable for its absence of wild horses and pigs, dormice, oxen, and hedgehogs, and true mice and rats (Mus). The single native sheep, as against the twenty species of sheep and goats of the Palæarctic Region, also typifies a remarkable deficiency of a widely distributed quadruped family.
The small birds of the Nearctic Region are, as a rule, well marked off from those of the Palæarctic province. The North American warblers belong to different families from the Palæarctic forms; the Nearctic flycatchers belong likewise to different groups from those at home; and the starlings are really "hangnests," or Icterida. The birds peculiar to the Nearctic Region are in turn well defined. The mocking-birds and blue-jays, the special cuckoos and the tanagers; the humming-birds; the wild turkeys and turkey buzzards, are all limited to this province. The humming-birds of the New World present certain extraordinary limitations in their distribution within the limits of the two regions comprising the Western hemisphere. The peaks and valleys of the Andes possess each its own species. On Pinchincha a peculiar species occurs, 14,000 feet above the sea level, and nowhere else ; another has been found only inside the crater of the extinct volcano of Chiriqui in Veragua ; a third occurs only on Chimborazo; and of another species only one specimen has ever been seen, the bird in question having been obtained, over forty years ago, in the Andes of Northern Peru.
Again, the presence of such distinct reptiles as the rattlesnakes among serpents, and the true iguanas among lizards, is highly characteristic of Nearctic lands. This region, lastly, may be described as the home of the tailed amphibians or newt-tribe. Nine
families—two peculiar Fig. 7. ANT. LOI'E.
to the region - and fifteen special genera represent the newts and salamanders, which include in their ranks the sirens, amphiumas, and two forms related to the European proteus of the caves of Carniola and the giant salamander of Japan respectively. There are also five families of fresh-water fishes-including two families of the rare ganoids--to be enumerated amongst the specific animal belongings of this large area.
There can be no question of the clear distinctness of the Nearctic Region from all other regions, including the Palæarctic, to which, however, in the general characters of its animal life, it is so closely allied. The species that are really common are northern or Arctic forms, a fact which to some extent would seem to point to former land connections in the north as a cause of the similarity. Notwithstanding the likeness in question, the Palæarctic and Nearctic regions are essentially distinct ; and there are no reasonable grounds for any scheme of uniting their varied interests in one common biological territory.
The Neotropical region extends from the southern limits of the Nearctic region, and includes the remainder of the New Worldthat is, Central and South America-with the West Indian Islands as a sub-region of the territory. No region of the world, if we except the Australian province, presents such a variety of interesting biological features as the Neotropical province. Whether regarded in the light of its existing life and of the diversity of animal and plant species it presents to view, or studied in the relations of its pre. sent animals to the geological past, the Neotropical area equals, if,