CHAP. XIV. J 



OF TEE TIMOR 6R0UF. 



207 



with Australia, because svi€li a large niimber of xavj abun- 

 dant and cliaraGteristic gioiips of Australian birds are 

 quite absent, and not a single Australian niamnml lias 

 entered Timor ; wbicli would certainly not have been the 

 case had the lands been actiially united Such groups as 

 the bower birtls (Ptdonorhynchus), tlie black and red 

 cockatoos (Calyjjtorliynchus), the blue wrens (Malnnis), the 

 CTOwshrikes (Cracticus), the Australian sluikes (Falcun- 

 culus and CoUuricincla), and many others, which abountl 

 all over Australia, would certiunlj have spread into Timor 

 if it had been imited to that country, or even if for any 

 long tune it had approaclied nearer to it than twenty 

 miles. Keither do any of the most characteristic groups 

 of Australian insects occur in Timor ; so that everything 

 combines to indicate that a strait of the sea has always 

 separated it from Australia, but that at one period this 

 strait was reduced to a width of about twenty niOes. 



But at the time when this narrowing of the sea took 

 place in one direction, there must have been a greater 

 separation at the other end of the chain, or we should hnd 

 more equality in the numbers of identical and representar 

 tive species derived from each extremity. It is true that 

 the widening of the strait at the Australian end by sub- 

 sidence, would, by putting a stop to imniigitition and inter- 

 crossing of individuals from the mother country, have 

 allowed full scope to the causes w^hich have led to the 

 modification of the species ; while the continued stream of 

 itumigi-ants from Java, would, by continual intercrossing, 

 check such modification. This view will not, however, 

 explain aU tlie facts ; for the cliaractcr of the fauna of the 

 Timorese group is inthcated as well by the forms wliich 

 are aljsent from it as by tliose which it contains, and is by 

 this kind of evidence shown to be much more Austrahan 

 than Indian. No less than twenty-nine genera, all more 

 or less abundant in Java, and most of wliich range over a 

 wide area, are altogether absent; while of the equally 

 diffused Austrahan genera oidy about fourteen are want- 

 ing. Tliis would clearly indicate that there has been, till 

 recently, a wide scpamtion from Java ; and the fact that 

 the islands of Bah and Lombock are small, and are almost 

 wholly volcanic, and contain a smaller number of modified 



