Fauna and Flora of New Zealand. 93 



Island*, and this cannot be due to difference of climate, be- 

 cause some parts of the South Island are further north than 

 parts of the North Island. Of the plants I am not competent 

 to speak, but a comparison of the floras on each side of Cook's 

 Strait would be of great interest f. Consequently the two 

 islands of New Zealand must have been separated during, at 

 least, the whole of the Pleistocene period. But an elevation of 

 500 feet would join them, and an elevation of 1100 feet would 

 lay bare the whole of Cook's Strait, so that we are driven to 

 the conclusion that this amount of elevation has not occurred 

 during the Pleistocene period, and consequently our glacier 

 epoch must have been earlier than the European glacial epoch. 

 On the other hand, the similarity of the land-shells, insects, 

 plants, birds, &c. forbids our placing the last separation 

 before the Pliocene. That is to say, New Zealand must have 

 stood more than 500 feet higher than at present during some 

 part of the Pliocene period ; for, if not, the plants and animals 

 on the two islands would have been more differentiated than 

 they are. 



But there is other and independent evidence that our glacier 

 epoch is older than the glacial epoch of Europe and North 

 America. First, there are the glacier phenomena themselves. 

 Several of the older lakes, such as those of the Rakaia and of 

 the central parts of Otago, have been completely filled up ; 

 while others, such as the lake in the Upper Dillon, Lake 

 Heron, Lake Tekapo, and Lake Pukaki, are approaching their 

 end. Glacier stria} are generally absent, although the rocks 

 still retain their rounded form ; and in the district of Central 

 Otago masses of rock 10 or 12 feet in thickness have been 

 removed from the mountains by ordinary atmospheric weather- 

 ing since the ice passed over themf. In the second place, 

 the drainage-system has been much altered since the glacier 

 epoch ; the gorges of the Kawarau, Dunstan, Mataura, and 

 Upper Taieri in Otago §, and that of the South Ashburton in 

 Canterbury, having been entirely cut since then. 



* South Island. North Island. 



Myiomoira macrocephula represented by M. toitoi. 

 Myioscopus albifrons ,, 31. loru/ipes. 



Turnagra crassirostris „ T. Hectori. 



Glaucopis cinerea „ G. Wilsoni. 



Ocydromus australis „ O, Earli. 



Apten/x australis „ A. Mantelli. 



t In the trans. N. Z. Inst. xvi. p. 466, Mr. W. T. L. Travers gives an 

 interesting table showing the distribution between the islands of sixteen 

 genera of plants ; but as no attempt is made to distinguish the differences 

 due to different station and climate from those due to isolation, it is not 

 available for my present purpose. 



% 'Geology of Otago,' p. 91. § Ibid. p. 94. 



Ann. & Mag. N. Hist, Ser. 5. Vol. xv. 8 



