PREFACE. 



At the end of the year 1832, a small work, under 

 the title of " Outlines of the Geographical Distribution 

 of British Plants" was privately circulated, in the 

 hope of obtaining such communications from others, 

 as would facilitate the preparation of a more extended 

 and more accurate work on the same subject. This 

 expectation has been partly fulfilled, though not to 

 the whole extent hoped for. The proposed work was 

 commenced; but it very soon became evident, that, 

 in order to complete such a work on the scale in- 

 tended, several years would be required, and (what 

 was more alarming) many volumes be filled. The 

 attempt was in consequence abandoned; and the 

 substitution of a small series of separate works, on a 

 much more humble scale, has been decided upon. 

 The following essay is one of these, and contains such 

 general and preliminary remarks, lists and tables, as 

 seem requisite to direct the attention of observers 

 towards those points, connected with the subject of 

 vegetable distribution, both as to facts and causes, 

 which appear to demand their first notice ; a tolerable 

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