466 NOTE ON THE FLORAS OF MK. FORBES. 



plants into * types of distribution ' was originally proposed 

 in a small volume entitled ' Remarks on the Geographical 

 Distribution of British Plants ; chiefly in connexion with 

 Latitude, Elevation, and Climate,' which was published in 

 1835. The types were there very briefly explained ; but 

 a tabular list of all the known British species was given 

 in an Appendix to the same volume, and each species 

 was severally referred to its appropriate type, after a labo- 

 rious comparison of published records and numerous ma- 

 nuscript notes of localities. The numerical value or 

 proportions of the types might thus be readily ascertained 

 by reckoning up the number of species assigned to each 

 of them. 



Ten years afterwards, in 1845, Mr. Edward Forbes, Pro- 

 fessor of Botany in King's College, London, made a com- 

 munication to the meeting of the British Association, 

 assembled at Cambridge, in which he announced that 

 " the vegetation of the British islands may be said to be 

 composed of five floras;" obviously meaning, that the 

 species might be arranged into five groups, in accordance 

 with peculiarities of their geographical distribution. To 

 account for these alleged five floras, he advanced a con- 

 jectural hypothesis, that their species had been created in 

 diflFerent places, and at different geological periods ; also, 

 that they had migrated into Britain from those diff'erent 

 places, by diff'erent routes, and at different and widely 

 distant periods ; which places, routes and periods he en- 

 deavoured to fix and explain. 



It is hoped that either a subsequent volume of this pre- 

 sent work, or a separate publication, may be devoted to 

 the external relations of British botany, treated in accord- 

 ance with the truths of Nature. At present the reader's 

 attention is requested simply to the distribution of plants 

 within Britain itself Omitting the Hebridean, which in- 



