CHAP. XIII. ] THE AUSTRALIAN REGION. 425 
with Australia was probably earlier than that with Java; since 
the majority of the Australian species have become modified, 
while the majority of the Oriental species have remained un- 
changed. This is due, no doubt, in part to the continued im- 
migration of fresh individuals from Java, after that from Australia, 
the Moluccas and New Guinea had almost wholly ceased. We 
must also notice the very small proportion of the genera, either 
of Australia or Java, that have found their way into these islands, 
many of the largest and most wide-spread groups in both coun- 
tries being altogether absent. Taking these facts into considera- 
tion, it is pretty clear that there has been no close and long- 
continued approximation of these islands to any part of the 
Australian region ; and it is also probable that they were fairly 
stocked with such Australian groups as they possess before the 
immigration from Java commenced, or a larger number of cha- 
racteristic Oriental forms would have been able to have estab- 
lished themselves. 
On looking at our map, we find that a shallow submerged bank 
extends from Australia to within about twenty miles of the coast 
of Timor; and this is probably an indication that the two 
countries were once only so far apart. This would have allowed 
the purely Australian types to enter, as they are not numerous; 
there being about 6 Australian species, and 10 or 12 representa- 
tives of Australian species, in Timor. All the rest may have been 
derived from the Moluccas or New Guinea, being mostly wide- 
spread genera of the Australian region; and the extension of 
Papua in a south-west direction towards Java (which was sug- 
gested as a means of providing New Guinea with peculiar Indo- 
Malay types not found in any other part of the region) may 
have probably served to supply Timor and Flores with the mass 
of their Austro-Malayan genera across a narrow strait or arm of 
the sea. Lombok, Baly, and Sumbawa were probably not then 
in existence, or nothing more than small volcanic cones rising 
out of the sea, thus leaving a distance of 300 miles between 
Flores and Java. Subsequently they grew into islands, which 
offered an easy passage for a number of Indo-Malay genera 
into such scantily stocked territories as Flores and Timor. The 
Vou. I.—29 
