396 MY LIFE [Chap. 



summary of the more important of them in the order in 

 which they were written. 



The first of these, read in January, 1863, at a meeting of 

 the Zoological Society, was on my birds from Bouru, and was 

 chiefly important as showing that this island was undoubtedly 

 one of the Moluccan group, every bird found there which was 

 not widely distributed being either identical with or closely 

 allied to Moluccan species, while none had special affinities 

 with Celebes. It was clear, then, that this island formed the 

 most westerly outlier of the Moluccan group. 



My next paper of importance, read before the same society 

 in the following November, was on the birds of the chain of 

 islands extending from Lombok to the great island of Timor. 

 I gave a list of one hundred and eighty-six species of birds, 

 of which twenty-nine were altogether new ; but the special 

 importance of the paper was that it enabled me to mark out 

 precisely 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 migration 

 of Javanese species due to the very narrow straits separating 

 most of the islands from each other. The following table will 

 serve to illustrate this : — 



This table shows how two streams of immigration have 

 entered these islands, the one from Java diminishing in 

 intensity as it passed on farther and farther to Timor ; the 

 other from Australia entering Timor and diminishing still 

 more rapidly towards Lombok. This indicates, as its 

 geological structure shows, that Timor is the older island and 

 that it received immigrants from Australia at a period when, 

 probably, Lombok and Flores had not come into existence 

 or were uninhabitable. This is also indicated by the fact that 

 the Australian immigrants have undergone greater modifica- 

 tion than the Javan. If we compare the birds of the whole 



