CHAPTER XIII. 
THE AUSTRALIAN REGION. 
THE Australian is the great insular region of the earth. Asa 
whole it is one of the best marked, and has even been considered 
to be equal in zoological value to all the rest of the globe; but 
its separate portions are very heterogeneous, and their limits 
sometimes ill-defined. Its central and most important masses 
consist of Australia and New Guinea, in which the main features 
of the region are fully developed. To the north-west it extends to 
Celebes, in which a large proportion of the Australian characters 
have disappeared, while Oriental types are mingled with them 
to such an extent that it is rather difficult to determine where to 
locate it. To the south-east it includes New Zealand, which is 
in some respects so peculiar, that it has even been proposed to 
constitute it a distinct region. On the east it embraces the 
whole of Oceania to the Marquesas and Sandwich Islands, whose 
very scanty and often peculiar fauna, must be affiliated to the 
general Australian type. 
Australia is the largest tract of land in the region, being 
several times more extensive than all the other islands combined, 
and it is here that the greatest variety of peculiar types have 
been developed. This island-continent, being situated in the 
track of the southern desert zone, and having no central moun- 
tains to condense the vapours trom the surrounding ocean, has a 
large portion of its interior so parched up and barren as to be 
almost destitute of animal life. The most extensive tract of 
fertile and well-watered country is on the east and south-east, 
