456 



ISLAND LIFE. 



[PAET II. 



hypothesis, which seems necessary to explain the occurrence of 

 so many species of these birds in a small area but of which we 

 have no independent proof. There are, however, some other 

 facts which would be explained by it, as the presence of three 

 peculiar but jellied genera of starlings, the three species of 

 parrots of the genus Nestor, and the six distinct rails of the 

 genus Ocydromus, as well as the numerous species in some cf 

 the peculiar New Zealand genera of plants, which seem less 

 likely to have been developed in a single area than when 

 isolated, and thus preserved from the counteracting influence 

 of intercrossing. 



In the present state of our knowledge these seem all the 

 conclusions we can arrive at from a study of the New Zealand 

 fauna; but as we fortunately possess a very full and accurate 

 knowledge of the flora of New Zealand, as well as of that of 

 Australia and the south temperate lands generally, it will be 

 well to see how far these conclusions are supported by the facts 

 of plant distribution, and what further indications they afford us 

 of the early history of these most interesting countries. This 

 inquiry is of sufficient importance to occupy a separate chapter. 



