10 liSTTRODUCTORY OBSERVATIONS. 



restricted range. The scope of this work must needs he 

 confined to a view of the present vegetation of Britain, 

 and of the manner in which the component species of 

 that vegetation are now distributed within the area of 

 Britain itself ; together with such inferences as maybe 

 drawn from existing circumstances, in regard to the pro- 

 bable origin of those species here ; that is, whether 

 placed in Britain by natural causes, or whether intro- 

 duced by human agency. Such have been the objects in 

 view while bringing together and examining the details 

 about species individually and separately, which are 

 printed in the three former volumes. And the same 

 object will be carried forward in the present volume, by 

 so re-arranging those details (augmented and corrected) 

 as to convert the individual and separated facts into col- 

 lective and comparative expositions. Though it will be 

 but a dry and unreadable manner of recording the infor- 

 mation, — one adapted for reference, rather than for read- 

 ing, — an arrangement of the species into tabular lists 

 seems best suited to effect the purpose in view ; and 

 much of this volume will consequently be devoted to 

 such lists. The greatest amount of special and general 

 facts can thus be recorded in a condensed form, under 

 different points of view ; and can thus be made read}'- for 

 the use of Phyto-geographers, whenever the botany of other 

 countries shall become portrayed in like manner. But 

 it will not be until the like arrangements have been 

 made for other countries, that Botanists will clearly 

 comprehend the use and bearings of the Cybele Bri- 

 tannica. 



No similar works are yet in existence, treating the 

 geographic botany of other countries in like detail and 

 fulness ; although there are many treatises of a more 

 general character, — which unfortunately means of a more 



