president's address. 851 



explain the fact by suggesting that reptiles have some unknown 

 and exceptional powers of dispersal. But if so, why is the 

 phenomenon limited to Polynesia'? And why should Mr. Wallace 

 himself explain the small number of reptiles in Great Britain and 

 Ireland Ijy the supposition that they are unable to ci'oss the 

 English and Irish Channels ?"* 



The results of the Challenger dredgings seem to show that the 

 principal part of the Pacific was ocean during the Tertiary 

 period, but it is not impossible that chains of volcanic islands or 

 masses of land may have existed during or before that period and 

 that these, being of a shifting character, at first connected with 

 a continent and afterwards cut off, might preserve the relics 

 of a continental fauna and flora. A continent properly so called 

 can scarcely have existed. The difliculties are too great in the 

 way of such a supposition, but only connections similar to that 

 which we are certain existed between New Zealand, New 

 Caledonia, the Fijis, and the main land which was perhaps at its 

 period of greatest development in a state of oscillation need be 

 conceded. 



Captain Button's theory of a bridge for the migration of 

 marsupials to Patagonia across the Pacific presents too many 

 difliculties, and my remarks above are by no means intended 

 to support the idea, for the absence of relics on the road is a 

 strong argument against it. Neither on the islands nor on the 

 mainland of Asia between Europe and the Malay Peninsula have 

 at present any fossil remains been found of those animals which 

 alike are represented in Tertiary Europe and Patagonia. 



The facts seem rather to point to the conclusion that the 

 Australian Marsupials were derived either from an ancient and 

 extended Patagonia or that the ancestors in both countries were 

 developed previously in some Antarctic region now submerged. 



Some ight on the subject of the former distribution of land 

 and water is thrown by Dr. H. von Jhering, who has kindly 



* New Zealand Journal of Science, Vol. i. 1883, p. 411. 



