450 
ISLAND LIFE. 
[part II. 
species, could have reached the places where they are now 
found ; and this gives us an idea of the complete series of 
changes through which New Zealand is believed to have passed 
in order to bring about its abnormally dense population of wing- 
less birds. First, we must suppose a land connection with some 
country inhabited by struthious birds, from which the ancestral 
forms might be derived ; secondly, a separation into many con- 
siderable islands, in which the various distinct species might 
become differentiated ; thirdly, an elevation bringing about the 
union of these islands to unite the distinct species in one 
area; and fourthly, a subsidence of a large part of the area, 
leaving the present islands with the various species crowded 
together. 
If New Zealand has really gone through such a series of 
changes as here suggested, some proofs of it might perhaps be 
obtained in the outlying islands which were once, presumably, 
joined with it. And this gives great importance to the state- 
ment of the aborigines of the Chatham Islands, that the 
Apteryx formerly lived there but was exterminated about 1835. 
It is to be hoped that some search will be made here and also in 
Norfolk Island, in both of which it is not improbable remains 
either of Apteryx or Dinornis might be discovered. 
So far we find nothing to object to in the speculations of 
Captain Hutton, with which, on the contrary, we almost wholly 
concur ; but we cannot follow him when he goes on to suggest an 
Antarctic continent uniting New Zealand and Australia with 
South America, and probably also with South Africa, in 
order to explain the existing distribution of struthious birds. 
Our best anatomists, as we have seen, agree that both Dinornis 
and Apteryx are more nearly allied to the cassowaries and emus 
than to the ostriches and rheas ; and we see that the form of 
the sea-bottom suggests a former connection with North Aus- 
tralia and New Guinea — the very region where these types 
most abound, and where in all probability they originated. The 
suggestion that all the struthious birds of the world sprang 
from a common ancestor at no very remote period, and that 
their existing distribution is due to direct land communication 
between the countries they novj inhabit, is one utterly opposed 
