78 HOLARCTIC REGION. [CH. II 



Australia. That there should be peculiar genera is quite 

 in accord with both these modes of origin ; but the fewness 

 of the peculiar genera and their alliance with Australian 

 forms seems to render it necessary to place the entire 

 Polynesian realm within the Australian, and at most to 

 regard it with Mr Wallace as a subregion (exclusive in 

 this case of the Solomons). 



Mr Sclater's regions the most convenient. 



The question is, What system shall we adopt ? 



The ideal system would be one which agreed entirely 

 with the distribution of land and sea and their inhabitants; 

 but that is unfortunately impracticable. The next best 

 is obviously the plan to try ; and Mr Sclater's regions are, 

 with an exception here and there, coincident with the 

 continents and larger islands. The great thing is not to 

 dispute the standard to be taken, but to agree in holding 

 to one standard. As a mere matter of convenience it is 

 immaterial whether we join Europe, Asia, and North 

 America into one Holarctic region, or use the current 

 terms of Nearctic and Palaearctic for the Old and New 

 World divisions of this extensive tract. What we want 

 to do is to find a common outline into which the details 

 can be inserted. Mr Wallace in a recent lecture upon 

 the regions most convenient for adoption 1 urges the 

 retention of the Sclaterian regions for the following three 

 principal reasons : 



(1) They are founded upon and approximate to the 

 great primary divisions of the earth, which there is reason 



1 Nature, 1894. 



