372 Mr. Alfred R. Wallace on the 



Australian : and in these the Pigeons are very unequally dis- 

 tributed ; for the western and larger portion (the Indo-Malayan 

 subregion) contains nine genera and forty-three species, while 

 the eastern and smaller portion (the Austro-Malayan sub- 

 region) has fifteen genera and eighty-four species. Here, 

 therefore, the species of Pigeons become more condensed and 

 more varied than in any other part of the globe : here is the 

 focus of the order ; and it was probably from this part of the 

 world that the original dispersal and modification of the 

 group chiefly took place. This condensation is carried to its 

 greatest height in New Guinea, in which, although only a few 

 points on its coast have been visited, no less than twenty- 

 five species of Pigeons have been obtained. 



I believe, therefore, that the distribution of Pigeons in the 

 Malay Archipelago fully confirms the results I have already 

 arrived at from the study of other groups of birds, mammalia, 

 and insects. These are, briefly, that this district is not one of 

 the primary divisions of the globe, but that while one-half of it 

 belongs to the Indian region, the other forms part of that of 

 Australia ; that the whole district may be further divided into 

 groups of islands, the productions of which have a very close 

 affinity — the Moluccan group being a satellite of New Guinea, 

 while the Timor group is more closely connected with Australia ; 

 that Celebes is a very isolated and remarkable island, which, 

 from the variety and peculiarity of its productions, appears 

 to be the remnant of some more extensive land, which existed 

 anterior to the present distribution of land and water in the sur- 

 rounding regions j and that New Guinea must be looked upon as 

 the remnant of a vast continent, now sunk beneath the waves of 

 the Pacific. We find, also, that among the Indo-Malay islands 

 (Sumatra, Java, and Borneo) Java is far the most isolated, 

 possessing a considerable number of species peculiar to itself, 

 while almost all those of Sumatra and Borneo are common to 

 those two islands. We learn from this that what at first sight 

 seems a very probable tradition of the Javans, the very recent 

 separation of their island from Sumatra, is the reverse of truth 

 since the evidence of the distribution of the Pittida, of the 

 Parrots, and of the Pigeons among birds, of the Squirrels 



