440 THE ZOOLOGIST. 



geological, indirectly refers to some of the most disputed points 

 in the discussion of zoo-geographical distribution. Dr. Guppy 

 tells us that his investigations were largely connected with the 

 study of plant-distribution, the details of which are promised in 

 a second volume. It is probable that no real knowledge of a 

 fauna or flora is possible without some acquaintance with the 

 geology of the floor on which they flourish, and it is more than 

 probable that the biology of the future will embrace a much 

 larger geological consideration than it does at present. 



Dr. Guppy has his own views and forms his own conclusions 

 on the debatable question of submerged continents ; he is con- 

 vinced that "islands have always been islands"; he denies that 

 there is any evidence that the various islands of the Fiji Group 

 were ever amalgamated, or that they were ever joined to the 

 Solomon Group. He thus gives no support to the hypothesis of 

 a Pacific Continent, nor to the theory of a Melanesian Plateau. 

 He advocates the view that these islands are due to " emerg- 

 ence," which has been in operation probably since the later 

 Tertiary period, and is even now not suspended. Such an argu- 

 ment, it is, however, admitted, cannot apply to Hawaii in the 

 North Pacific, which exhibits no evidence of emergence, and 

 bears the impress of antiquity by the number of its endemic 

 plants and animals, and his hypothesis must therefore be con- 

 fined to the southern portion of the tropical Pacific. Conse- 

 quently the fauna and flora of the Fijis must be considered as 

 due to derivative migration, and not to the survivors of an older 

 and submerged continent. Beyond the work of ocean currents, 

 Dr. Guppy refers much to the direct agency of birds, more par- 

 ticularly as to plant distribution, but for proofs and details on 

 this question we must await the publication of the second volume. 



Whether these views are generally accepted, or the reverse, 

 there can be no doubt that this volume affords a brilliant example 

 of the way in which a purely geological study can be made the 

 preface for the most important zoological discussion. 



