138 IV. PHYSICAL GEOGRAPHY. 



deemed a western province, although it has a line of 

 eastern coast likewise. 



As to the three groups which together make up the 

 province of the North Isles. One group is completely 

 western, namely, the Hebrides ; another is eastern by 

 longitude, namely, Shetland ; and the intermediate group 

 of Orkney is eastern with respect to Scotland, western 

 with respect to England. In climate and productions all 

 three might appropriately go along with Western Scot- 

 land. In the Summary of Distribution they are so 

 taken ; and almost the only result of any importance is, 

 that the one or two species peculiar to Shetland are there 

 entered as exclusively western ; namelj% Arenaria norve- 

 gica and the more doubtful Cerastium nigrescens. It 

 would have been a better geographical arrangement origi- 

 nally (if a paucity of botanical records had not then pre- 

 vented) to have united the Hebrides with the West High- 

 land province, instead of uniting these isles with the two 

 more northerly and easterly groups. Botanically, it may 

 be deemed indiilerent with which of those two provinces 

 the Hebrides are associated. They contain no plants 

 peculiar to the group, and extremely few which are not 

 recorded also for Orkney or Shetland ; most of their spe- 

 cies being common to both the latter-named groups. 



The areas of the two longitudinal divisions, or more 

 strictly those of the two sides of the island, here traced 

 out, may be given in square miles thus : — 



West Britain 43,833. East Britain 43,580. 

 The proportion of mountainous land is larger on the 

 western side. In South Britain, only the western side is 

 mountainous ; the undulating plains of the South of 

 England lying chiefly on the eastern side of the island. 

 In advancing northwards, the eastern side becomes moun- 

 tainous also. There is little difi^erence between the abso- 



