The geographical distribution of animals, with a study of the relations ...

438 ZOOLOGICAL GEOGRAPHY. [part hi.the Himalayas had risen to any great height, and when a largepart of what are now the cold plateaus of Central Asia mayhave teemed with life, some forms of which are preserved inAfrica, some in Malaya, and a few in Celebes. Here mayhave lived the common ancestor of Stis, Babimsa, and Phacochosrus; 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 thepresence of the North-Indian forms in Celebes ;and it offers lessdifficulties than a direct connection with continental Africa, whichonce appeared to be the only solution of the problem. If thissouth-eastward extension of Asia occurred at the same time asthe north-eastward extension of South Africa and Madagascar,the two early continents may have approached each other sufficientlyto have allowed of some interchange of forms : Tarsiusmay be the descendant of some Lemurine animal that thenentered the Malayan area, while the progenitors of Cryptoproctamay then have passed from Asia to Madagascar.It is true that we here reach the extremest limits of speculation; but when we have before us such singular phenomena asare presented by the fauna of the island of Celebes, we can hardlyhelp endeavouring to picture to our imaginations by what pastchanges of land and sea (in themselves not improbable) the actualcondition 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 theearlier part of this chapter, it will not be necessary to occupy muchtime on this sub-region, which isas remarkably homogeneous asthe one we have just left is heterogeneous. Although much ofthe northern part of Australia is within the tropics, while Victoriaand Tasmania are situated from 36° to 43° south latitude,there is no striking change in the character of the faunathroughout the continent ;a number of important genera extendingover the whole country, and giving a very uniform characterto its zoology. The eastern parts, including the colonies of NewSouth Wales and Queensland, are undoubtedly the richest, several