270 VI. EXPLANATIONS OF THE 



been before remarked. Such segregates are now less familiar to many 

 botanists ; so that often llieir localilies remain unrecorded, or are 

 perhaps recorded erroneously for some other allied species. Many 

 botanists give little attention to grasses, sedges, willows, brambles, roses, 

 and other plants not easy to discriminate ; the consequences being 

 similar, in the species being less recorded or mis-recorded, in com- 

 parison with other plants of greater interest to collectors, or more 

 satisfactorily distinct and distinguishable. So, likewise, various incon- 

 spicuous species are probably often overlooked, and thus supposed to be 

 more rare than is the fact; nobody would overlook the Clematis or 

 Bryonia, if actually looking out for plants ; though many might pass 

 the Limosella or Littorella unobserved. These and various other cir- 

 cumstances will always interfere with our attempts either to place 

 plants in a consecutive series, or to combine them into groups, in 

 accordance with their true rarity or frequency. 



It might seem needless to add further, that a census list for Britain 

 in general cannot be applicable to any one separate county or other 

 section of the whole island. Nor could lists for a few isolated spots 

 make more than a highly imperfect approach towards a true census for 

 entire Britain. And yet the blundering stupidity of some writers, who 

 attempt phyto-geographical statistics, and who even pretend to prescribe 

 rules and methods for ascertaining the relative frequency of plants, 

 shows loo plainly that the local conditions may be confused with the 

 general, — that half-a-dozen or half-a-score records of parochial abun- 

 dance or scarcity may be misconstrued into an adequate geographical 

 census of species. 



Second. — In regard to the columns of figures which follow the names 

 of the plants under distinctive initial letters. These figures indi- 

 cate the number of subprovinces for large sections or divisions of 

 Britain ; and are intended to give some idea respecting the part of 

 Britain in which each species is more or less fully distributed. The 

 first double column, with the head letters S and N, shows the number 

 of subprovinces for South Britain, as distinguished from JVliddleand 

 North Britain ; the two latter being taken together. As eiiplaiued on 

 page 135, the former includes 18 subprovinces, and the two latter divi- 

 sions include 20. In order to render the numerical contrast more 

 exact, the subproviiice of East Trent, coiresponding with the county of 

 Lincoln, is here reckoned along with South Britain, instead of Mid 

 Britain. The two letters will be explained thus : — 



