Did Australia ever form jiart of Asia ? 71 



that remote age of the globe. But if even it be accepted 

 tliat during the Eocene or earliest tertiary period there ex- 

 isted in Europe under similar climatic conditions flora of 

 Conifer ce^ Proteacece^ Myrtacece, and Casuarince^ such as Aus- 

 tralia now possesses, the question still arises as to how the 

 vegetation of a locality so remote should have been trans- 

 ferred to antipodean Europe ? Making all due allowance 

 for the astonishing influence exercised by winds, waves, and 

 the migration of animals over the diffusion of vegetable 

 species, yet the means of transport by the ocean or by 

 currents of water is confined within narrow limits, and 

 under the most favourable conditions is limited to the very 

 few plants which can maintain their powers of reproduction 

 uninjured by immersion in water, and those on the other 

 hand which, on being transported to a strange shore, find 

 there the means of existence and increase. As, moreover, the 

 observations which Professor linger has made upon the diffu- 

 sion of species of plants at that remote period, and their very 

 accurately circumscribed limits, run directly counter to the 

 opinion of those naturalists who hold to a variety of centres 

 of development, (instancing a case where one species of 

 plants is found in two widely separated regions,) have never 

 been satisfactorily refuted, the learned botanist thereupon 

 proceeds to the conclusion, that during the Eocene period 

 Australia was united to the main-land through the Moluccas. 

 ThifS land route has been followed at one period by Araucarias, 

 ProteacecB, sandal wood, and a hundred other varieties of tree 



