WORLD-DISTEIBUTION OF THE BRITISH CARYOPHYLLACE.E. 189 



4. That out of tbe 15 species additional to the above 14, which 

 belt the world in the north temperate zone (groups 2 and 6, with Ce- 

 rastium latifolinm omitted), 1 only (Silene nocti/Iord) is an annual weed 

 of cultivated ground, the other 14 (with doubt attaching to Silene injlaia 

 for the New World) are all plants that there is no reasonable chance 

 that human agency has interfered to disseminate. 



5. That 12 of the species belong to a set of plants that descend 

 only to low levels in high latitudes, and in Britain and through Central 

 Europe are found only in mountainous places, usually at a considerable 

 elevation above the level of the sea. Note the wide general area of 



. dispersion which under these very peculiar circumstances these plants 

 nevertheless attain, 7 of the species reaching all round the world. This 

 is a point which it would be interesting to have illustrated in full detail, 

 but to do this would stretch this paper out beyond reasonable l^ounds. 



6. That we cannot, upon consideration of the dispersion of the spe- 

 cies in Britain and through the rest of the world, see that the fact of 

 our insular position makes any appreciable difference in our flora. 

 Britain has no species confined to it, and possesses boreal and non- 

 boreal species, dispersed through it in the same way in which it might 

 be expected they would be if it formed part of the Continent, without 

 any German Ocean intervening. 



7. The remarkable correlation that exists between the dispersion of 

 the species in Britain and over the whole globe. The species of groups 

 6, 8, and 9 (with the half exception of Sagina subidata) are all " High- 

 land " or " Scottish " in their type of distribution through Britain; 

 and for the non-boreal species, the sequence of the species, arranging 

 them according to their frequency, corresponds to a large extent. This 

 point also it Avould be interesting to follow out in detail. 



Finally, looking back upon the whole matter, whether we believe 

 that each of these 59 species has always kept its individuality intact, 

 and been dispersed from a single centre, or whether we hold that the 

 types have been materially changed through bygone ages, what a vista 

 for reflection upon the length of time and amount of change in the 

 physical condition of the world needful to account for such a condition 

 of things as we see at the present time spread before us does such a 

 muster roll of facts as this open out ! 



