The geographical distribution of animals, with a study of the relations ...

460 ZOOLOGICAL GEOGRAPHY. [part hi.an outline sketch of the main features of the New Zealandfauna and of its relations with other regions, we may considerwhat conclusions are fairly deducible from the facts. As theoutlying Norfolk, Chatham, and Lord Howe's Islands, are allinhabited (or have recently been so) by birds of New Zealandtype or even identical species, almost incapable of flight, we mayinfer that these islands show us the former minimum extent of theland-area in which the peculiar forms which characterise thesub-region were developed. If we include the Auckland andMacquarie Islands to the south, we shall have a territory of notmuch less extent than Australia, and separated from it by perhapsseveral hundred miles of ocean. Some such ancient landmust have existed to allow of the development and specializationof so many peculiar forms of birds, and it probably remainedwith but 'slight modifications for a considerable geological period.During all this time it would interchange many of its forms oflife with Australia, and there would arise that amount of identityof genera between the two countries winch we find to exist.extension southwards, perhaps considerably beyond the Macquaries,would bring it within the range of floating ice duringcolder epochs, and within easy reach of the antarctic continentduring the warm periods ;of genera and species withItsand thus would arise that interchangeSouth America, which forms one ofthe characteristic features of the natural history of New Zealand.Captain F. W. Hutton (to whose interesting paper on theGeographical relations of the New Zealand Fauna we areindebted for some of our facts) insists upon the necessity offormer land-connections in various directions, and especiallyof an early southern continental period, when New Zealand,Australia, Southern Africa, and South America, were united.Thus he would account for the existence of Struthious birdsin all these countries, and for the various other groups ofbirds, reptiles, fishes, or insects which have no obvious meansof traversing the ocean,—and this union must have occurredbefore mammalia existed in any of these countries. Butsuch a supposition is quite unnecessary, if we consider thatall wingless land-birds and some water-birds (as the Gare-fowl