A DROWNED CONTINENT 123 



many difficulties with which to contend. One of these 

 is the practical absence of all non-volant mammals from 

 Polynesia, with the exception of the Solomon group, where 

 a few cuscuses and rats are found. But the case of the 

 West Indies — where there is every probability that there 

 was formerly a large mammalian fauna, the majority of 

 which were drowned by submergence — may very likely 

 afford the solution of the difficulty. Worms and slugs 

 would probably find means of survival in circumstances 

 where mammalian Yik would disappear. This explanation 

 will, however, clearly not apply in the case of New Zealand, 

 where, if mammals had ever existed, their remains would 

 almost certainly have been discovered. It must be assumed, 

 then, that if Polynesia was the route by which the faunas 

 of Australia and Patagonia were formerly connected, New 

 Zealand was at that time isolated. And, indeed, seeing 

 that the presumed land connection between the areas in 

 question must have existed at a comparatively late epoch, 

 it is most likely that the ancient Polynesian land was 

 already broken up to a considerable extent into islands and 

 archipelagos, so that the main line of communication may 

 have been but narrow, and from time to time interrupted. 

 Indeed, it must almost of necessity have been very in- 

 complete and of short duration after the introduction of 

 modern forms of life, as otherwise the types common to 

 Australia and Patagonia would have been much more 

 numerous than we find to be the case. Hence there is 

 no improbability in the suggested isolation of New Zealand 

 during the period in question. 



But, putting these interesting speculations aside, the 

 results of the Funafuti boring indicate almost without 

 doubt that Polynesia is an area of comparatively recent 

 subsidence, and it has already been mentioned that there 



