INDO-MALAY ISLd^YDS. 



143 



peopled from each other and from the continent without 

 some former connexion. For if such tiad been the mode of 

 stocking tlieni with animals, it is quite certain tliat creatures 

 vvliich can lly long distances would be the lirst to spread 

 from island to island, and thus pioduce an almost perfect 

 uniformity of species over the whole region. But no such 

 uniformity exists, and the bats of each island are almost, 

 if not quite, as distinct as the other mammals. For 

 example, sixteen species are known in Borneo, and of 

 these ten are found in Java and five in Sumatra, a propor- 

 tion about tlie same as tliat of the liodenta, which liave no 

 direct means of migration. We learn from this fact, tliat the 

 seas which separate the islands from each other are wide 

 enough to prevent the passage even of flying ainmals, and 

 that we must look to the same causes as having led to the 

 luusent distribution of botli groups. The only sutlicienfc 

 cause we can imagine is the former connexion of all the 

 islands with the continent, and such a change is in perfect 

 hai-mony with what we know of the earth's past history, 

 and is rendered probable by the remarkable fact that a 

 rise of only three hundred feet woidd convert theM'ide seaa 

 that separate them into an immense winding valley or plain 

 about three hundred miles 'wide and twelve hundred long. 



It may, perhaps, lie thought that birds which possess 

 the power of jlight in so pre-eminent a degree, would not 

 he limited in their range by arms of the sea, and would 

 thns afford few indications of the former union or separa- 

 tion of the islands they inhabit. This, however, is not the 

 case. A very large number of birds appear to be sis strictly 

 limited by watery barriers as are quadmpeds ; and as they 

 have been so much more attentively collected, we have 

 more complete materials to work upon, and are enabled 

 to deduce from them still more definite and satisfactory 

 results. Some groups, however, such as the aquatic birds, 

 the waders, and the birds of prey, are great wanderers ; 

 other groups are little known except to ornithologists, I 

 shall therefore refer chiefly to a few of the best known 

 and most remarkable famiUes of birds, as a sample of the 

 conclusions furnished by tlie entire class. 



The birds of the Indo-Malay region have a close resem- 

 blance to those of India ; for though a very large pmportion 



