70 MAMMALS. 



of new people, not increasing, perhaps gradually diminishing, but for long iDieserviug the memory 

 of a different and bygone state of things ? I imagine they would neither covet their fastnesses 

 nor seek to deprive them of them. The labour of toiling to the top of mountains is distasteful 

 to these races, not to speak of the aimless warfare they would hav6 to encovmter, and the black races 

 would be allowed to enjoy their sterile fastnesses unmolested. Such is the fate which I believe has 

 befallen the Hill tribes ; and these are the groimds on which I think that if there is nothing 

 but their geographical distribution to prevent us referring them to the great black race on 

 the ground of their physical attributes, we maj' venture to follow that course. 



There are other facts founded on the distribution of animals and plants, in India and the Austra- 

 lian region, which give support to the explanation of the position of the Hill tribes which I have above 

 suggested. From the fact of a large proportion of the animals which are found in Borneo, Java, 

 and Sumatra, being identical with those found on the mainland, there is little or no doubt that 

 these islands must at some former period have been united to it ; so that it appears that before 

 the present upward movement, which these are now undergoing, there must have been a down- 

 ward one, and before that again an upward one, as we have seen is probably the case with 

 other countries. The islands must have been first united with the mainland to allow the inter- 

 communication of species. A subsidence must then have taken place to throw them into 

 something like tlieir present configuration, and there is now again a gradual rise reuniting them 

 slowly to the mainland. 



Now, Dr. Joseph Hooker, in his Flora of Australia,* gives a list of nearly 500 plants 

 found in that country, which are either identical, or very nearly so, with continental or insidar 

 Indian spjcies ; but, on the other hand, he states that there is scarcely a single Australian tj'pe 

 to be found in India, and the few that occur are in Eastern India. It would appear as if there 

 had been * no reciprocity, that all the mutual types have been borrowed from India, and that 

 Australia had given none in return (for 10, which is the number, against 500 can scarcely be called 

 reciprocity). Now, this is quite in accordance with the course of events, which I have supposed 

 to have occurred. If Australia and India v^-ere united for a time, a mutual communication of their 

 respective floras must have followed, as a necessary conseqiieuce. If, when India sunk, the tops 

 of the mountains, whore the Hill tribes still exist, were not submerged, a certain jjroportion of 

 the flora would bo there preserved. When, long afterwards, India again emerged from below the 

 waters, a new Indian flora woidd graduall}- be developed out of the remnant left on the tops of 

 the mountains to supjilj' the new lands : but as the new emergence went no further soutli than 

 Ceylon, the new types could not find their way to Australia. There appear to have been only 

 ten Australian plants which have found their way by flotsam and jetsam from Australia to India, 

 against 500 Indian plants which remain in Australia by ancient continuity. If there is any 

 foundation for the above speculation, the connexion between India and Australia must have been 

 very ancient, and at a time when one or other of them was not in a condition to supply the other 

 with mammals, although it could with plants. 



I must not occupy the time of the reader here with botanical speculations, which will come 

 better wiien we reach that branch of our subject, but I cannot refrain from citing one instructive 

 instance in favour of the existence of the connexion already indicated between Africa and south- 

 west Australia. It is long since a connexion between the vegetation of these countries has been 



* " Flora of Australia," liy Jos. L). IIo )KE:{. Inti-oductory Essay, p. xlii. (18.09). 



