The geographical distribution of animals, with a study of the relations ...

chap, xiii.] THE AUSTRALIAN REGION. 425with Australia was probably earlier than that with Java ; sincethe majority of the Australian species have become modified,while the majority of the Oriental species have remained unchanged.This is due, no doubt, in part to the continued immigrationof fresh individuals from Java, after that from Australia,the Moluccas and New Guinea had almost wholly ceased.must also notice the very small proportion of the genera,Weeitherof Australia or Java, that have found their way into these islands,many of the largest and most wide-spread groups in both countriesbeing altogether absent.Taking these facts into consideration,it is pretty clear that there has been no close and longcontinuedapproximation of these islands to any part of theAustralian region ; and it is also probable that they were fairlystocked with such Australian groups as they possess before theimmigration from Java commenced, or a largernumber of characteristicOriental forms would have been able to have establishedthemselves.On looking at our map, we find that a shallow submerged bankextends from Australia to within about twenty miles of the coastof Timor; and this is probably an indication that the twocountries were once only so far apart.This would have allowedthe purely Australian types to enter, as they are not numerous;there being about 6 Australian species,and 10 or 12 representativesof Australian species, in Timor.All the rest may have beenderived from the Moluccas or New Guinea, being mostly widespreadgenera of the Australian region; and the extension ofPapua in a south-west direction towards Java (which was suggestedas a means of providing New Guinea with peculiar Indo-Malay types not found in any other part of the region) mayhave probably served to supply Timor and Flores with the massof theirthe sea.Austro-Malayan genera across a narrow strait or arm ofLombok, Baly, and Sumbawa were probably not thenin existence, or nothing more than small \olcanic cones risingout of the sea, thus leaving a distance of 300 miles betweenFlores and Java. Subsequently they grew into islands, whichoffered an easy passage for a number of Indo-Malay generainto such scantily stocked territories as Flores and Timor. TheVol. I.—29