106 Origin of the Fauna and Flora of New Zealand. 



extending through Australia to India*, was isolated from 

 Australia towards the close of the Jurassic periodf, but was 

 attached to a South-Pacific continent and received a stream of 

 immigrants from the north. None arrived from the south, 

 because Fuegia was not then in existence. In the Upper 

 Cretaceous the land shrank to a size considerably smaller than 

 at present. In the Eocene, elevation took place and New 

 Zealand extended outwards in all directions, but remained, 

 isolated from other lands. Plants and animals came in both 

 from the north and from the south. In the Oligocene and 

 Miocene periods New Zealand was, except for a short interval, 

 a cluster of islands, but was upraised once more, and obtained 

 more immigrants from north and south during the Pliocene ; 

 after which subsidence occurred, and the land throughout the 

 South Island and southern half of the North Island sank consi- 

 derably below its present level, to be again elevated during 

 the Pleistocene period. 



It has been objected that we have no right to infer that 

 because elevation or subsidence can be proved to have occurred 

 in one particular district of the earth's surface therefore this 

 elevation or subsidence extended over neighbouring areas. 

 But the more the geology and palaeontology of large geogra- 

 phical regions, like North America or Europe, are studied, 

 the more clearly we see that subterranean movements have 

 affected large regions simultaneously, or nearly simultane- 

 ously, and that the local deviations from uniformity are com- 

 paratively small. So it comes about that we have in each 

 large geographical area a series of rock systems which are 

 nearly synchronous over the whole area, although not synchro- 

 nous with those in other and distant areas. 1 think that our 

 knowledge of the palaeontology of Australasia is already 

 sufficient to show that we have here also another of those 

 large geographical areas which, when viewed on a large scale, 

 has been moved uniformly ; and therefore that the rock- 

 systems of New Zealand can be correlated with those of 

 Australia, and perhaps, in the earlier periods, with those of 

 the peninsula of India. 



Of course it is not denied that a scattered immigration may 

 have been going on ever since the Cretaceous period ; but it 

 is asserted that this immigration has been small and almost 

 inappreciable in comparison with the rushes that took place 

 from the north in the Lower Cretaceous, and from both north 

 and south in the Eocene and Pliocene periods. The emigra- 



* This is the Indo-oceanic continent of Mr. H. F. Blanford (Quart. 

 Journ. Geol. Soc. xxxi. p. 535). 



t I need hardly say that I use these terms with very wide margins. 



