CHAP. XX CELEBES 461 



possessing representatives of the greater part of these 

 expensive and important families of birds ? To get rid 

 altogether of such varied and dominant types of bird-life 

 by any subsequent process of submersion is more difficult 

 than to exterminate mammalia ; and we are therefore ao-ain 

 driven to our former conclusion — that the present land of 

 Celebes has never (in Tertiary times) been united to the 

 Asiatic continent, but has received its population of Asiatic 

 forms by migration across narrow straits and intervening 

 islands. Taking into consideration the amount of affinity 

 on the one hand, and the isolation on the other, of the 

 Celebesian fauna, w^e may 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 

 mammalian 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 

 marsujDials 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 Avhich 

 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 



