VI. LOCAL SPECIES. 443 



6. Local Species. 



Subject to the remarks in the preceding section, on the 

 areas and limits of plants, many of the inequalities of 

 distribution in Britain may be conveniently traced, and in 

 some degree also explained, in connexion with the geo- 

 graphical divisions of the surface by lines of latitude and 

 longitude, or with elevation above the sea-level. This 

 has been exemplified in some detail by the lists and 

 tables printed on preceding pages, and will receive some 

 further elucidation a few pages onward. 



But many of the plants are either too local or too 

 general, to exhibit any limitary connexion with latitude 

 or longitude. A species distributed through the entire 

 length and breadth of the island, and passing probably to 

 other countries northward and southward of Britain, can- 

 not be said to have such limits here. And on the con- 

 trary, some of the plants which are restricted to a single 

 province or two, or even smaller sections of surface, may 

 have their very local distribution related to other condi- 

 tions more closely than to lines of latitude or longitude. 

 If special lists of the most local plants should be required 

 for any purpose, they can readily be made out either from 

 the ' census of species ' or from the ' areas of species.' 

 In the former, they stand together at the latter part of 

 the list, as species peculiar to a single sub-province, or 

 to two or three sub-provinces. In the latter, they are 

 more scattered ; but are still easily distinguished by the 

 single or few provincial nos. set after their names. 

 Looking to the last group of the census, the 77 plants 

 restricted to a single sub -province may be apportioned 

 between the divisions of Britain thus : — 



South Britain, 44. Mid and North Britain, 33. 

 Or, looking to the ternary division, which disjoins 



