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 | 
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 key | 
afford the solution of the difficulty. Worms and slugs } 
would probably find means of survival in circumstances 
where mammalian life 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 
