MAMMALIAN REGIONS. 311 



tave also some claims to stand alone as separate regions, their forms of ornitliic life being in many- 

 cases peculiar and local. If tliey can be attached anywhere, however, it is to Australia."* 



So far as the Pacific Islands are concerned a few Bats are the only mammals found on them, 

 and, therefore, much on either side cannot bo inferred from their presence, especially as they belong 

 to types which extend to India and China as well as to Australia. StUl, the inferences from their 

 belonging to forms also found in Australia do not, so far as they go, contradict any indications 

 in this direction which can be di-awn from other classes of organised beings. These, however, 

 are but few and indistinct. 



The distribution of Mammals in New Guinea and Austialia teaches us something regarding 

 the disj miction of the lauds, and also something regarding the origin of species, confirmatory, as 

 I read it, of change of condition playing an important part in the process of development. The 

 point of resemblance between them in Mammals is the occurrence of marsupial animals in New 

 Guinea as well as ia Australia. But the New-Guinea forms arc mostly, as already mentioned, of 

 peculiar tyjjes, usually so cb'stinct as not to fit into any of the old genera, so that new genera liave 

 to be made for their reception. There are Kangaroos ; but with one excej)tion (the Filander) 

 thej' are Tree Kangaroos (Dexdrglagus). There are Phalangers, but they are of the genus Cuscus. 

 For long, these forms were supj^osed to be confined to New Guinea. The number of species 

 known has gradually increased, but they always came from New Guinea or its dependencies. But, 

 lattei-ly, it has been ascertained tliat they are not absolutel}^ confined to that district, and that 

 species are also found in the nearest points of Australia. A Tree Kangaroo has been foimd in 

 North Australia, and a Cuscus on Cape York, the north-east point of Australia. The occurrence 

 of these species there seems to prove that the disjvmction of the two coimtries must have been 

 pretty long a-doiug, and that the country between the two passed through the same half-drowned 

 condition as that of the present coast of New Guinea, where the Dendrol.\gits is now found. 

 If New Guinea had been summarily^ divorced from Australia, and new species had sprung up in 

 it, the new forms woidd have been confined to it. They coidd only be found in Australia by the 

 animal floating or swimming across, which I may be permitted to say is at least not a likely 

 mode of progression for a Kangaroo. But if we suppose the disjunction to have proceeded at a 

 slow pace, and the peculiar conditions of the land (whatever they may have been) to have existed 

 ■ long enough to have allowed the production of new species before the final sei^aration was actually 

 consummated, we should then have a simple explanation of the presence of those New-Guinea 

 forms in Australia. That they are rare probably shows that the disjunction must have been 

 nearly comjjleted by the time they had begun to appear, and that they are still confined to the points 

 of Australian land nearest to New Guinea seems to warrant one of two inferences ; either that species 

 are slow to leave their country, or that when they do so and get into lands with new conditions of 

 life they are transformed into other species, or die off. 



Having been so recenth^ engaged in discussing the different provinces into which Australia 

 is divided, I shall merely refer the reader back to the two last chapters for information on lliat 

 point. The occurrence of one or more Papuan Marsupials in the New Hebrides shows that that 

 group belongs to the New-Guinea district, and not to the Polj-nesian. 



IV. The Americax Region. — The whole of the Amoriran Continent, both North and Soutli, 



* SCLATEIt, op. cit. p. 141. 



