CHAP. XX CELEBES 461 



narrow seas and intervening islands. Taking into con- 

 sideration the amount of affinity on the one hand, and the 

 isolation on the other, of the Celebesian fauna, we mav 

 probably place the period of this earlier migration in the 

 early part of the latter half of the Tertiary period, that is, 

 in middle or late Miocene times. 



Celebes not Strictly a Continental Island. — A study of the 

 mammalia and of the bird-fauna of Celebes thus leads us 

 in both cases to the same conclusion, and forbids us to rank 

 it as a strictly continental island on the Asiatic side. But 

 facts of a very similar character are equally opposed to 

 the idea of a former land-connection with Australia or New 

 Guinea, or even with the Moluccas. The numerous 

 marsupials of those countries are all wanting in Celebes, 

 except the phalangers of the genus Cuscus, and these 

 arboreal creatures are very liable to be carried across 

 narrow seas on trees' uprooted by earthquakes or floods. 

 The terrestrial cassowaries are equally absent ; and thus 

 we can account for the presence of all the Moluccan or 

 Australian types actually found in Celebes without sup- 

 posing any land-connection on this side during the Tertiary 

 period. The presence of the Celebes ape in the island of 

 Batchian, and of the babirusa in Bouru, can be sufficiently 

 explained by a somewhat closer approximation of the 

 respective lands, or by a few intervening islands which 

 have since disappeared, or it may even be due to human 

 agency. 



If the explanation now given of the peculiar features 

 presented by the fauna of Celebes be the correct one, we 

 are fully justified in classing it as an " anomalous island," 

 since it possesses a small but very remarkable mammalian 

 fauna, without ever having been directly united with any 

 continent or extensive land ; and, both by what it has and 

 what it wants, occupies such an exactly intermediate 

 position between the Oriental and Australian regions that 

 it will perhaps ever remain a matter of opinion wdth which 

 it should properly be associated. Forming, as it does, the 

 western limit of such typical Australian groups as the 

 Marsupials among mammalia, and the Cacatuidae, Tricho- 



