EDITOR S PREFACE. 



XXI 



even of our own island is made up of contributions from at 

 least four different sources, namely, Scandinavia, Germany, 

 Trance, and Spain; thus supplying Edward Forbes and 

 other eminent geologists with an argument in favour of the 

 former existence of a land communication between Great 

 Britain and each of those countries. 



A similar hypothesis is adopted by Dr. Joseph Hooker 

 to explain the facts which he had ascertained, by personal 

 observation, during his exploration of the regions of the 

 South Pacific ; such as the occurrence of the same plants 

 in spots so detached one from the other as Puegia and 

 Kerguelen's Land, that of the Edwardsia grandiflora in- 

 habiting alike New Zealand and South America, and of the 

 Oxalis Magellanica being found in these same localities, as 

 well as in Tasmania, although the seeds of neither plant are 

 light enough to be wafted by the air, or so compact or olea- 

 ginous as to be transported uninjured by the waters. 



But whilst he is thus led to speculate upon the possibility 

 of the plants conterminous to the South Pacific being the 

 remains of a flora that had once spread over a larger and 

 more continuous tract of land than now exists within the 

 confines of that Ocean, and to regard the Antarctic Islands 

 as representing the remnants of a mountain-chain, of which 



