No. 537] ZOOGEOGRAPHY OF THE EAST INDIES 559 



islands of the series from Bali to Ombaai; and the Sara- 

 sins believe that it was in reality one of the oldest, al- 

 though more recent than the Strait of Macassar, and thus 

 well within the Secondary Epoch. This allows US to 

 explain a certain faunistic differentiation between Bali 

 and the other islands; for we know, for instance, that 

 cockatoos do not occur further to the westward than Loin 

 bok. This was one of the weightiest arguments which 

 Wallace used. However, cockatoos live in the Philip- 

 pines, and thus well to the westward of his own line. 

 Weber points out that the fauna of the Lesser Sunda 

 Islands is in large part an impoverished Indian one 

 derived from Java, beside which there occurs a small 

 element from Celebes (along the Flores bridge). So also 

 by the same means has come a slight infiltration of Philip- 

 pine forms. Here also we find a few Papuasian or Aus- 

 tralian species. Timor appears, indeed, to have received 

 some animals directly from New Guinea or Australia 

 (birds, Hyla). 



