Phytogeography of the Southwestern Pacific 193 



tus),theevidenceis in favor of the northern origin, the Boronieae 

 being speciaUzed Xanthoxyleae, and the genus Eucalyptus a 

 progressive derivative of the Malesian Syzygium type. 



The argument deduced from the genetic resemblance of such 

 genera is strengthened by a great many examples of relations 

 which, in analyzing the flora, we recognize as Malaysio-Aus- 

 tralian. These relations are found not only in orders peculiar 

 to the Palaeotropics (for example, in Pandanus and Musa), but 

 also in many orders common to Asia and America. Even here 

 the Australian genera or species are more closely allied to the 

 Asiatic forms. This is true for : 



Cycadaceae Monimiaceae § Mollinedieae 



Palmae Menispermaceae § Cocculinae 



Araceae Simarubaceae 



Dioscoreaceae Loganiaceae 



Zingiberaceae Gesneriaceae 

 Anonaceae 



The same feature is to be observed in many endemic genera of 

 the Australian flora. 



From this fact it is evident that these relations are not attrib- 

 utable to recent events, but to conditions of a more remote 

 period. This is confirmed by the extension of, for example, Pitto- 

 sporaceae, Pritzelia, and Dioscorea hastifolia to the central parts 

 of the continent and to southwestern Australia. 



Therefore, the connection between Malaysia and Australia 

 must have lasted for a long time in different forms, and may con- 

 tinue to the present day, at any rate in species with efficient 

 means of distribution. As a consequence, this Malaysian compo- 

 nent comprises groups of each degree of classification. There are 

 numerous genera distributed from southern India to eastern 

 Australia, and even many species are found everywhere from the 



