438 ZOOLOGICAL GEOGRAPHY. [part in. 



the Himalayas had risen to any great height, and when a large 

 part of what are now the cold plateaus of Central Asia may 

 have teemed with life, some forms of which are preserved in 

 Africa, some in Malaya, and a few in Celebes. Here may 

 have lived the common ancestor of Sits, Babirusa, and Phaco- 

 chcerus ; as well as of Cynopithecus, Cynocephalus, and Macacus ; 

 of Anoa and Bubalus; of Scissirostrum and Euryceros; of Ceyx, 

 Ceycopsis, and Ispidina. Such an origin accounts, too, for the 

 presence of the North-Indian forms in Celebes ; and it offers less 

 difficulties than a direct connection with continental Africa, which 

 once appeared to be the only solution of the problem. If this 

 south-eastward extension of Asia occurred at the same time as 

 the north-eastward extension of South Africa and Madagascar, 

 the two early continents may have approached each other suffi- 

 ciently to have allowed of some interchange of forms : Tardus 

 may be the descendant of some Lemurine animal that then 

 entered the Malayan area, while the progenitors of Cryptoprocta 

 may then have passed from Asia to Madagascar. 



It is true that we here reach the extremest limits of specula- 

 tion ; but when we have before us such singular phenomena as 

 are presented by the fauna of the island of Celebes, we can hardly 

 help endeavouring to picture to our imaginations by what past 

 changes of land and sea (in themselves not improbable) the actual 

 condition of things may have been brought about. 



II Australia and Tasmania, or the Australian Sub-region. 



A general sketch of Australian zoology having been given in the 

 earlier part of this chapter, it will not be necessary to occupy much 

 time on this sub-region, which is as remarkably homogeneous as 

 the one we have just left is heterogeneous. Although much of 

 the northern part of Australia is within the tropics, while Vic- 

 toria and Tasmania are situated from 36° to 43° south latitude, 

 there is no striking change in the character of the fauna 

 throughout the continent ; a number of important genera extend- 

 ing over the whole country, and giving a very uniform character 

 to its zoology. The eastern parts, including the colonies of New 

 South Wales and Queensland, are undoubtedly the richest, several 



