Hurron.—On the Geographical Relations of the N.Z. Fauna. 233 
species living on so small an island is very remarkable when contrasted with 
other parts of the world. The continent of Africa, including Arabia, contains 
but one, or according to some naturalists two, species of ostrich. South 
America, from Patagonia to Peru, has but three species of rhea, each inhabit- 
ing a separate district. Australia possesses two species of emu, one on the 
eastern and the other on the western side, and one species of cassowary 
on the northern, while five other species of cassowary inhabit other detached 
islands, from New Britain and New Guinea to the Molucca Islands. I 
believe that outside of New Zealand no two species of Struthious bird are 
found living in the same district, while here we have now four species of kiwi 
and not long ago had at least half-a-dozen species of moa as well. How can 
this be accounted for? The solution is readily found by examining the 
distribution of the cassowaries. Here we have six species inhabiting six 
isolated localities. If now this region of the earth were to be elevated these 
- six species might mingle, and if it were subsequently to sink again, all six 
species would undoubtedly be driven to the higher lands, and we should have 
in this supposed island a representation of New Zealand inhabited by six 
species of Struthious bird. 
In order, therefore, to account for the numerous species of Dinornis we 
must suppose an ancient continent, inhabited by one or two species, to sink, 
and the birds to take refuge on the different mountain ranges left as islands 
above the water. We must suppose that they remained thus isolated from 
one another for a sufficiently long period to allow of specific changes being 
brought about ; that then, by an elevation of the land they once more mingled 
together, and that, on subsidence ‘again taking place, New Zealand as the 
central mountain chain formed a harbour of refuge for them all. 
Whether this isolation of species points to some cause as yet unrecognized, 
by which in the struggle for life no two species of Struthious bird can live in 
close proximity I will not venture to give an opinion, but it is a fair subject 
for inquiry, and one on which the careful study of the relative ages of moa 
bones might throw considerable light, and enable us perhaps to understand the 
great mortality that must have taken place amongst the moas when confined 
to these small islands long before man set his foot here. 
The distribution, therefore, of the Struthious birds in the Southern 
Hemisphere points to a large Antarctic Continent stretching from Australia 
through New Zealand to South America, and perhaps on to South Africa. 
This continent must have sunk, and Australia, New Zealand, South America 
and South Africa must have remained isolated from one another long enough 
to allow of the great differences observable between the birds of each country 
being brought about. Subsequently New Zealand must have formed part of 
a smaller continent, not connected either with Australia or South America, 
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