IV. EXPLANATIONS. 369 



generally, and in the vegetable kingdom at large. Nytnan's ' Sylloge 

 FlorsB Europasae' has supplied the requisite data for the fifih column; 

 those for the sixth column being derived from Lindley's 'Vegetable 

 Kingdom.' The numbers are doubtless very incomplete for the earth 

 generally; but the statements and guesses about them, as set forth in 

 the latter work, are probably the best yet placed on record in any single 

 treatise. The absolute numbers are perhaps false in every instance ; and 

 if regarded as approximate calculations or estimates they are certainly 

 of unequal truth ; and so far they can '^ive only imperfect comparisons. 

 An enumeration of the orders, placed in a series according to the num- 

 ber of British species they include, may well enough represent their 

 comparative share in constituting the flora of this island. But by itself 

 it would of course fail to show by what ordinal peculiarities the flora of 

 Britain is distinguished from that of the earth generally, or of Europe, 

 or of any given country. And in seeking to know the phyto-geographical 

 features of Britain itself, we should ascertain wherein they differ from 

 the floral physiognomy elsewhere. 



2. Distributive Census.— This designation is given to the repetition of 

 the orders in a second series because their numerical values are there 

 stated for eight different divisions of the island, not as one collective 

 whole. Thus stated, they become data for comparing the botany of one 

 portion of Britain with another, or that of the whole with its parts. In 

 repeating the series, a change has been made from the ordinal to the 

 generic name, in those orders having only a single genus to represent 

 them in Britain. Three treble columns of figures succeed the list of 

 names. The first column states the number of species in each order for 

 total Britain, and for its western and eastern divisions, before explained 

 on pages 136 to 139. The second column states the numbers for the 

 southern, middle, and northern divisions of the island, also before 

 explained on pages 134 to 136. The third column states the numbers 

 for the three ascending stages of tle\iition, as they were explained on 

 page 230. The numbers are counted from the ' Summary of Distribu- 

 tion,' with some half-dozen alterations and corrections. 



The series of ordinal and generic names might be re-arranged iu 

 accordance with the predominating figures iu any of the columns ; and 

 when so re-arranged they would of course represent the botany of the 

 corresponding division of the island, regarded from the systematic jjoint 

 of view. The series for the eastern and western divisions would continue 



VOL. IV. 



^B 



