460 ZOOLOGICAL GEOGRAPHY. [PART III. 
an outline sketch of the main features of the New Zealand 
fauna and of its relations with other regions, we may consider 
what conclusions are fairly deducible from the facts. As the 
outlying Norfolk, Chatham, and Lord Howe's Islands, are all 
inhabited (or have recently been so) by birds of New Zealand 
type or even identical species, almost incapable of flight, we may 
infer that these islands show us the former minimum extent of the 
land-area in which the peculiar forms which characterise the 
sub-region were developed. If we include the Auckland and 
Macquarie Islands to the south, we shall have a territory of not 
much less extent than Australia, and separated from it by per- 
haps several hundred miles of ocean. Some such ancient land 
must have existed to allow of the development and specialization 
of so many peculiar forms of birds, and it probably remained 
with but slight modifications for a considerable geological period. 
During all this time it would interchange many of its forms of 
life with Australia, and there would arise that amount of identity 
of genera between the two countries which we find to exist. Its 
extension southwards, perhaps considerably beyond the Mac- 
quaries, would bring it within the range of floating ice during 
colder epochs, and within easy reach of the antarctic continent 
during the warm periods ; and thus would arise that interchange 
of genera and species with South America, which forms one of 
the characteristic features of the natural history of New Zealand. 
Captain F. W. Hutton (to whose interesting paper on the 
Geographical relations of the New Zealand Fauna we are 
indebted for some of our facts) insists upon the necessity of 
former land-connections in various directions, and especially 
of 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 birds 
in all these countries, and for the various other groups of 
birds, reptiles, fishes, or insects which have no obvious means 
of traversing the ocean,—and this union must have occurred 
before mammalia existed in any of these countries. But 
such a supposition is quite unnecessary, if we consider that 
all wingless land-birds and some water-birds (as the Gare-fowl 
