Malaysian Phytogeography and Polynesian Flora 255 



In relation to Polynesia, it is naturally the eastern part o£ 

 Malaysia that is o£ the greatest biological interest, for it is from 

 this region that most of the Malaysian types of plants now found 

 in Polynesia have been derived. There has been in Polynesia a 

 certain amount of dissemination of plants by v^ater, but the 

 number of species having adaptations to this end is very limited. 

 Other plants have been disseminated through the medium of 

 winds and migratory birds. There are, however, many genera 

 characteristic of Malaysia-Polynesia that have no manifest adap- 

 tations for any of these methods of dissemination. One is forced 

 to postulate a different distribution of land areas at some time 

 in the past, to explain the present-day distribution of plants and 

 animals. These land areas probably were of considerable size, 

 not the narrow land-bridges which have been widely scattered 

 over the Pacific basin by some theorists. 



Effective north and south distribution is limited by tempera- 

 ture, but within the humid tropics this factor is inoperative. 

 Thus, except for a very few high-altitude plants in Luzon, there 

 is no evident connection between the Philippine and the Japa- 

 nese floras. Even the species distributed between Formosa and 

 the Philippines are few in number and none is dominant in 

 either region; and, strikingly, none of the characteristic Papuan 

 and eastern Australian types, so well developed on the Philip- 

 pines, reaches Formosa.* 



The north and south distribution in eastern Malaysia is more 

 extensive than is generally realized. Such characteristic species 

 as Uncinia rupestris Raoul and Blechntim fraseri Luerss., origi- 

 nally known only in New Zealand, now stand thus : the Uncinia, 

 New Zealand and the Philippines; the Blechnum, New Zealand, 



* Merrill, E. D., 1923. Die pflanzengeographische Scheidung von Formosa und 

 den Philippinen. Bot. Jahrb., 58:599-604. 



