Fauna and Flora of New Zealand. 103 



when New Zealand was reduced to a number of islands*, or 

 else part must have arrived in the Pliocene and part in the 

 Eocene, at both of which times New Zealand extended much 

 further to the south. Let us try to see which of the two is 

 the more probable. 



It would be a great mistake to suppose that our alpine 

 flora is almost exclusively composed of plants of antarctic or 

 north-temperate origin. Of 189 species of alpine plants be- 

 longing to 64 genera, I find that 48 per cent, are of antarctic 

 (including north-temperate) origin, 37 per cent, are sub- 

 tropical, and 15 per cent, belong to endemic genera. As 

 about 44 per cent, of the total flora is antarctic, 48 per cent, 

 subtropical, and 18 per cent, endemic, it would appear that 

 the special adaptation of antarctic plants to cold regions has 

 not availed them very much. For, composing 44 per cent, 

 of the whole vegetation, they have only attained to 48 per 

 cent, of the alpine flora. Some of our alpine species belong 

 to quite subtropical genera, as Myrsine i Cyaihodes, Dacry- 

 diurn i and Phyllocladus ; but there is no large genus in New 

 Zealand that is not represented by alpine forms. On the 

 other hand, only about 35 per cent, of the antarctic species 

 are alpines, the other 65 per cent, living on the lowlands ; and 

 out of 56 antarctic genera, about one half have no alpine 

 species at all. Again, out of 189 New-Zealand alpine species 

 only 13 are found elsewhere (9 in Australia or Tasmania, and 

 4 in Fuegia) so that 93 per cent, are endemic. Out of 64 

 alpine genera only 17 are confined to the Alps, and 7 of these 

 are endemic. These facts show that our alpine flora has, on 

 the whole, grown out of the lowland flora, and that the arrival 

 of alpines, as alpines, has been quite exceptional. The an- 

 cestral forms have arrived on the lowlands and their descen- 

 dants have gradually worked their way up the mountains. 

 Mr. Wallace has remarked that alpine plants are particularly 

 well placed for dispersal, on account of the high winds so 

 common in mountains. This is quite true, and explains their 

 migration from mountain-top to mountain-top along a chain ; 

 but it will not apply to the spread of plants to distant islands, 

 because, although more seeds of alpine than of lowland plants 

 would be blown away, all would arrive on the island at or 

 near sea-level, and thus the alpines would not find their ac- 

 customed station, while the fewer seeds blown or carried by 

 -birds from lower levels would have a better chance of living 



* There is evidence that an elevation occurred between the deposition 

 of the Oamaru and Pareora systems ; but this elevation was slight, and 

 New Zealand was probably of no greater extent at that time than it is 

 now. 



