260 E. D. Merrill 



It may be that Wegener's hypothesis of continental shift has 

 its bearing on both the separation and the intermingling of the 

 AustraUan and Asiatic faunas and floras in Malaysia, if it be 

 assumed that Australia, formerly more widely separated from 

 Asia, moved toward Asia and, in so doing, crushed the south- 

 eastern borders of an ancient, larger Asiatic continent. Before the 

 shift took place, intermigrations were impossible; after the shift, 

 plants and animals could move to a limited degree in both direc- 

 tions. This hypothesis has been applied to the problem of plant 

 distribution in Malaysia by Doctor Lam.* 



We can only theorize concerning the underlying causes for the 

 peculiar distribution of Australian types, which extend into Poly- 

 nesia and eastern Malaysia, including the Philippines, but do 

 not reach to any marked degree into western Malaysia. Our 

 knowledge of the tremendously developed Malaysian flora and 

 fauna is limited, and any conclusions based on the data now 

 available concerning the distribution of known genera and spe- 

 cies may be radically modified as exploration progresses and the 

 compilation of geographic distribution data becomes more com- 

 plete. Conclusions based on the known distribution of any one 

 group, be it genus, family, or any other category, are notoriously 

 unsafe. Conclusive generalizations can be safely based only on 

 the consideration of all groups, and here the specialist fails be- 

 cause of his inability to master and evaluate the details of geo- 

 graphic distribution of organisms outside of his own special field. 



It is safe to assume, however, that, whatever have been the 

 causes leading to the present-day distribution of Malaysian life, 

 no investigator of the fauna and flora of Polynesia can safely 



* Lam, H. J., 1930. Het genetisch-plantengeografisch Onderzoek van den 

 indischen Archipel en Wegener's Verschuivingstheorie. Tijdschr. Nederl. Aard- 

 drijksk. Genootsch., 47:553-581; niaps 6-7. 



