86 PEOCEEDINGS OF THE 



The species generally found on and near cultivated land were not 

 tabulated and they are not included in the maps of this paper. 

 There are 113 of them. Of these 8 are species of Fumaria. 8oine 

 of them and probably Linaria supina may be true natives in at 

 least a part of the British Isles and might be transferred to 

 class 3 where they would add to the Atlantic element. The 

 remainder of the species of this class extends far into the Mediter- 

 ranean region. No attempt has been made in this place to map 

 the species of classes 2 and 3 separately. Tliey are therefore 

 represented collectively in the maps. It is, liowever, obvious 

 that the inclusion of the littoi-al species contributes largely to the 

 deeper shading of the coastal regions. To what extent this is the 

 case will be seen in the following paragraphs. 



The number of species recognised as " .Southern " is 155 and of 

 those of class 1 (in and near cultivated land) 13, so that 142 are 

 included in map 1. Of these 66 are represented in the map of 

 the Atlantic and 76 in that of the Mediterranean elements. 



Southern Elements considered fjeneralhj (Map 1). — The definition 

 of " Southern Elements " as given on page 85 is illustrated 

 very clearly in the inset of map 1, so that it appears unnecessary 

 to enlarge on that point. Looking at the main map, we are 

 struck by two features — the extreme concentration of the Southern 

 elements in a narrow belt on the Channel Coast and their thinning 

 out towards tlie interior, and in Great Britain also towards the 

 north and north-east. The Channel belt would appear still 

 narrower if it were feasible to map the Southerns according to 

 their actual areas instead of the vice-counties in which they 

 occur, and the same applies to the littoral zones generally ; but 

 problems like the present, in which we have to deal with general 

 phenomena and broad averages, are treated better on a wide basis. 

 However, there is among the Southern element one class of 

 plants which is tied to the coasts as such, and apart from cliujatic 

 conditions. They are plants peculiar to sea-cliffs, sandy shores, 

 salt marshes, &c. These "littorals," as we may call them brietly, 

 share in the crowding of the Southern elements towards the 

 coasts, and this share requires to be gauged correctly. They form 

 almost exactly one-third (33*8 per cent.) of the total of the 

 Southerns. They are relatively more numei'ous — though only 

 slightly so — -in Great Britain than in Ireland, their percentages 

 being 30 (48 out of 134) and 30 (24 out of 81) respectively. 

 This preponderance is noticeable on all the coasts of Great 

 Britain, but most marked on the East coast, where 41'3 per cent, 

 of the Southerns are littoral, the corresponding figures for the 

 South and West being 35-25 per cent, and 34*3 per cent. In 

 Ireland, on the other hand, the eastern and western coasts have 

 about equal shares in littoral Southerns. Consequently, if we 

 were to exclude this littoral class, we should see the blank area 

 in the north and north-east of Great Britain (map 1) expand 

 very much towards the south, particularly on the east coast, while 

 some of the hatched shading of the coastal zones would pass into 



