230 AHCTIC ANIMALS. [CH. V 



divergent the further they are removed from the hypo- 

 thetical seat of origin. This can be defended by a series 

 of facts. There has been of late a considerable amount of 

 discussion as to the value of the Palsearctic and Nearctic 

 regions of Mr Sclater. It has been proposed to unite 

 them into one common region to which the name Holarctic 

 has been applied by Prof. Newton. This is accepted by 

 Dr Heilprin in his work upon Geographical Distribution. 

 More recently Mr Wallace has defended the retention of 

 the two separate regions. The present object is not to 

 attempt to decide upon the relative values of these two 

 opinions but to emphasise the fact that there has been a 

 discussion, and to point out that there never has been any 

 question as to the distinctness of two such regions as the 

 Neotropical and the Oriental. An ingenious reconciliation 

 has been suggested by Dr Hart Merriam who would 

 institute a Boreal region cut off from Nearctic, and joined 

 to the Palsearctic leaving the rest of the Nearctic alone 

 as a distinct " Southern " region. This proposal brings 

 into prominence the very close resemblance of the circum- 

 polar fauna; indeed out of the 30 genera of mammals 

 in the Boreal region only 10 are peculiar to America. 

 If we were to adopt a slightly different plan and cut off a 

 boreal region or Arctic region as it has been termed from 

 both Palsearctic and Nearctic the almost complete identity 

 of the circumpolar fauna would be clearly demonstrated. 

 Such animals as the Reindeer, the Glutton, the Elk, the 

 Lemming, the Arctic Fox are circumpolar in range. 

 Between the Palsearctic and the Nearctic, after this large 

 slice has been cut off from both, there is not a little 



