48 DATA FOR DETERMINING 



rank among the rarest of British plants. These examples 

 will indicate the use of the table towards determining the 

 comparative scarcity or frequency of species. It would 

 be easy to group the species in lists according thereto ; 

 but as this would be merely a repetition, though dif- 

 ferently arranged, of the information contained in the 

 table, I avoid the additional type and paper that would 

 be required. My object is to condense such matters as 

 much as possible. It is usually a more facile task to make 

 a large book, than to convey the same actual information 

 in a small one. 



III. REMARKS ON THE DATA FOR DETERMIN- 

 ING THE DISTRIBUTION OF PLANTS WITHIN 

 BRITAIN. 



The latitudinal extent of Britain, the varied elevation 

 of its surface, its peculiar geographical position between 

 an immense ocean on the one side and a wide continent 

 on the other, with the local differences in its climate de- 

 pendent on these peculiarities, would naturally lead a 

 botanist to expect considerable diversity in its vegetation 

 at the opposite extremities of the island, as well as in the 

 low plains and on the mountain heights. This, indeed, 

 is so obvious on the most superficial examination, that 

 every British disciple of Flora is aware of the fact ; but 

 the amount of these differences, and the peculiarities in 

 the range and limits of species, have been very little in- 

 vestigated, although such an inquiry opens out to the 

 student of nature, views far more exalted, and a field of 

 research far wider and more interesting, than the mere 

 collection and examination of individual objects can ever 

 afford to him. The commonest weed thus acquires an 



