14 THE WANDERINGS OF ANIMALS [OH. 



and space, occasionally the past of North and South 

 with the present East and West. 



In short, there are no generally applicable zoo- 

 logical regions, not even for each class taken separately, 

 unless the life of this class is confined to a compara- 

 tively short geological period. Most of the greater 

 groups have far too long a history and have evolved 

 many successive divisions. Let us take the mammals. 

 Marsupials or pouched mammals still live in Australia 

 and in both Americas because they existed already 

 in Mesozoic times. But hoofed beasts, Ungulata, ex- 

 isted at one time or other all over the world, except 

 in Australia, because they, as a group, are post- 

 Cretaceous. Deer and bears, as examples of still 

 more recent northerners in origin, are found on every 

 continent except Australia and Africa. Each of these 

 groups teaches a valuable historical lesson, but when 

 these and others are combined into a few mammalian 

 realms or regions they mean nothing but statistical 

 majorities. If there is one at all, Australia is such 

 a realm backed against the rest of the world, but as 

 certainly it does not represent an original mammalian 

 creative centre. So far as mammals are concerned, 

 New Zealand has none indigenous ; it is a Mesozoic 

 derelict, and is a ' region ' with a negative character. 

 Australia became a separate complex after it had 

 received, not evolved, the stock of its most character- 

 istic fauna which has since flourished so as to produce 



