112 MOSTLY MAMMALS 



and feeding at night. If these creatures were of a type 

 near to that from which the other marsupials of Australia 

 have sprung, they might be considered as survivors from 

 a migration of marsupials which it has been suggested 

 took place at a remote epoch from Asia to Australia. But 

 they are not so, and it is therefore clear that this hypo- 

 thesis will not account for their presence in the island. 

 As they are so completely arboreal in their habits, they 

 are, however, just the kind of creatures which we might 

 naturally expect to be wafted from one island to another on 

 floating timber; and it is far from improbable that it is to 

 this mode of transport they owe their presence in Celebes. 

 All the other mammals are of an Oriental type, although 

 several of them are quite unlike their relatives on the 

 mainland and other islands. Among them one of the 

 most remarkable is the babirusa, a curious little pig in 

 which the tusks of both jaws in the males attain a most 

 extraordinary development, the lower ones rising straight 

 upwards, while the upper ones grow right through the 

 skull to curve backwards in a bold sweep towards the 

 eyes. Although nothing definitely is known as to the 

 origin of this strange animal, yet it is evidently a highly 

 specialised offshoot from the ancestral pigs of Asia. Equally 

 peculiar is the tiny little black buffalo, or anoa, described 

 in another article, which is not much larger than a good- 

 sized ram, and has upright horns quite unlike those of the 

 ordinary Asiatic buffalo. In the island of Mindanao, the 

 most southern of the Philippine group, there is, however, 

 a considerably larger buffalo, known as the tamarao, which 

 serves to connect the anoa with the ordinary Asiatic species. 

 More important still is the occurrence in the Tertiary 

 deposits of Northern India of several species of buffaloes 

 intimately related to the anoa. Clearly, then, this animal 



