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

336 ZOOLOGICAL GEOGRAPHY. l^rt hi.great islands were recently united to the continent, and thattheir separation took place by one general subsidence of thewhole. It is more consonant with what we know of such matters,that the elevations and depressions were partial, varyingin their points of action and often recurring ; sometimes extendingone part of an island, sometimes another ; now joiningan island to the main land, now bringing two islands intocloserproximity. There is reason to believe that sometimes an interveningisland has sunk or receded and allowed others which itbefore separated to effect a partial union independently of it. Ifwe recognise the probability that such varied and often-renewedchanges of level have occurred, we shall be better able to understandhow certain anomalies of distribution in these islands mayhave been brought about. We will now endeavour to sketch thegeneral features of the zoology of this interesting district, andthen proceed to discuss some of the relations of the islands toeach other.Mammalia.—We have seen that the Indo-Chinese sub-regionpossesses 13 species of mammalia in common with the Indo-Malay sub-region, and 4 others peculiar to itself, besides oneEthiopian and several Oriental and Palsearctic forms of widerange. Of this latter class the Malay islands have comparativelyfew, but they possess no less than 14 peculiar genera, viz.Simia, Siamanga, Tarsius, Galcopithecus, Hylomys, Ptilocerns,Gymnura, Cynogale, Hemigalea, Arctogale, Barangia, Mydans,Hdarctos, and Tapirus. The islands also possess tigers, deer,wild pigs, wild cattle, elephants, the scaly ant-eater, and mostof the usual Oriental genera ; so that they are on the wholefully as rich as, if not richer than, any part of Asia ;a fact veryunusual in island faunas, and very suggestive of their reallycontinental nature.Plate VIII. Scene in Borneo with Characteristic MalayanQuadrupeds.—The Malayan fauna is so rich and peculiar thatwe devote two plates to illustrate it. We have here a group ofmammalia, such as might be seen together in the vast forests ofBorneo. In the foreground we have the beautiful deer-likeChevrotain [Tragulus javanicus). These are delicate little