Alfred Russel Wallace 



The next paper of importance, read before the same 

 Society in November (1863), was on the birds of the chain 

 of islands extending from Lombok to the great island of 

 Timor. This included a list of 186 species of birds, of 

 which twenty-nine were altogether new. A special feature 

 of the paper was that it enabled him to mark out pre- 

 cisely the boundary line between the Indian and Australian 

 zoological regions, and to trace the derivation of the rather 

 peculiar fauna of these islands, partly from Australia and 

 partly from the Moluccas, but with a strong recent migra- 

 tion of Javanese species due to the very narrow straits 

 separating most of the islands from each other. In '' My 

 Life " some interesting tables are given to illustrate how 

 the two streams of immigration entered these islands, and 

 further that " as its geological structure shows . . . Timor 

 is the older island and received immigrants from Australia 

 at a period when, probably, Lombok and Flores had not 

 come into existence or were unhabitable. . . . We can," 

 he says, '^ feel confident that Timor has not been con- 

 nected with Australia, because it has none of the peculiar 

 Australian mammalia, and also because many of the com- 

 monest and most widespread groups of Australian birds 

 are entirely wanting."^ 



Two other papers, dealing with parrots and pigeons 

 respectively (1864-5), were thought by Wallace himself to 

 be among the most important of his studies of geogra- 

 phical distribution. Writing of them he says : '* These 

 peculiarities of distribution and coloration in two such 

 very diverse groups of birds interested me greatly, and I 

 endeavoured to explain them in accordance with the laws 

 of Natural Selection." 



In March, 1864, ha^^ng begun to make a special study 

 of his collection of butterflies, he prepared a paper for the 

 1 " My Life," i. 396-7. 



