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 Palearctic 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 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 Palearctic 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 Palearctic province. The North American warblers belong to different families from the Palearctic 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.

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 Palearctic, 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 Palearctic 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 present animals to the geological past, the Neotropical area equals, if,

indeed, it does not in some features excel in interest, the great island-continent itself. The monkeys of the Neotropical region, for example, are totally different from those of any other region of the globe. They are broad-nosed, and usually possess prehensile tails, adapting them for an active life amid the dense forests of the region. Those

apes have no callosities; their thumbs are less perfectly developed than in Old World apes; and cheek-pouches are also wanting. They include (Fig. 8) the spider monkeys, howlers, capuchins, marmosets, and many other peculiar and special forms. The bats

are likewise peculiar, in that they are represented by the famous vampires and other blood-sucking species. The rodents are the chinchillas, the curious capybara, the pacas, and agoutis and tree porcupines, possessing, like the apes, prehensile tails. The carnivora include the racoons,

which take the place in this region of the weasels of the Old World. Deer and llamas represent the ruminants of the region; and the tapir and peccaries represent

FIG. 9. ANT-EATER.

other forms of hoofed quadrupeds. It is the group of the Edentate quadrupeds, however, which finds in Neotropical territory its peculiar home. If the marsupial kangaroos and wombats characterise Australia as their head-quarters, no less typically in South America do the sloths, true ant-eaters (Fig. 9), and armadillo (Fig. 10) represent the fulness of Edentate development. With the exception of a few species of scaly ant-eaters or pangolins (Fig. 11) occurring in

the Ethiopian and Oriental regions, and the "aardvark" or ground hog of South Africa, the Edentate mammals are absolutely confined to the Neotropical Region; and it is in the recent deposits of South America that we likewise discover the fossil remains of those huge extinct edentata, of which the Megatherium, Mylodon, and Glypto

may be mentioned the Insectivora, of which order-represented by the moles, shrews, and hedgehogs-not an example exists in this area, if we except a little shrew in the north, and one genus in the West Indian Islands. Then, also, we may note the absence of sheep and oxen; there are none of the civets, so widely spread over other areas; and there is an absence of the large carnivora, and of the elephants and rhinoceroses of the Old World.

Equally notable are the birds of the region. The smaller Passerine birds of the region (Formicaroid Passeres), curiously enough, want the singing muscles of the larynx, as a rule. To this group belong the ant-thrushes, tree creepers, tyrants, chatterers, and manakins. Other typical birds of this area are the tanagers, toucans, puff

thology. The humming-birds, ranging from Sitka to Patagonia, from the plains to the towering heights of the Andes, are absolutely confined to the New World "No naturalist," says Mr. Wallace, " can study