328 POPULAR GEOGRAPHY OF PLANTS. 



belief that England possessed within its own limits a special 

 flora, created originally within those limits; and we are 

 moreover reminded that its species are identical with those 

 of the Continent. 



There is, indeed, another manner in which an area of 

 land often becomes gradually covered with plants, namely, 

 by the means of transport with which they are provided ; 

 such, for instance, as seed-down, or by the agency of cur- 

 rents of water which convey the seed, or by that of birds. 

 But with regard to some portion of the British flora, such 

 a method is considered unlikely ; first, because the plants 

 themselves are not adapted by their nature for such trans- 

 port; and, secondly, because certain groups of plants on 

 which the theory rests are not universally dispersed over 

 our islands, as we may conclude they would have been (had 

 they been transported), by the same means which first in- 

 troduced them, but are " congregated in such a way as to 

 form distinct regions or provinces, which have remained 

 unchanged as long as we have any record," sketched out 

 moreover " in the likenesses of distant and distinct lands." 



As neither of these two methods original creation within 

 the island, or that of transport into it appears adequate to 

 account for the distribution of plants which now exists, a 



