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On the Geographical Distribution of British Plants. 

 By the Rev. W. H. Coleman, M.A. 



Much valuable advice has been given to the authors of local Floras 

 in the several works of Mr. Watson, and the present writer has largely 

 profited by his suggestions. Having been long engaged in a work of 

 this nature, and therefore having, as he trusts he may say without 

 presumption, acquired some experience, he has thought that some 

 account of the method pursued by himself and his colleague may be 

 acceptable to the readers of the ' Phytologist,' and useful to those 

 who shall hereafter be engaged in any similar work. 



In collecting materials for a Flora of an English county, it was soon 

 discovered that the work would be extremely imperfect, as a view of 

 the botanical productions of the county collectively, unless not only 

 diligent search had been made for the rarer species in every part of 

 it, but also some security could be given that the prevalence of the 

 plants presumed to be common was uniform throughout it. Some 

 years after observations had been commenced, it was found that so 

 little progress in this respect had been made, that if the materials had 

 then been published, the work could hardly have been called a Flora of 

 the county, but merely one of two or three of the principal towns, with 

 some scattered records of the rest of the county. It was no satisfac- 

 tion, however it might have proved an excuse, to observe that many 

 others of our local Floras were liable to the same objection ; and it 

 was therefore determined to seek a remedy for the defect. 



The first plan that suggested itself for this purpose was that of 

 forming catalogues of plants found within a circle of five miles radius 

 round each of the principal towns of the county. But upon tracing 

 these circles on a map it was found that some of them would partially 

 overlie one another ; while large tracts remote from any large town 

 would still be excluded. Some plan was therefore sought which should 

 not be liable to either of these objections. And first the purely geo- 

 metrical one was tried of dividing the whole county into a series of 

 irregular hexagons, by joining the points dissecting the distance be- 

 tween every two adjacent principal towns. This was easily enough 

 done on the map, but was found to be useless in the field, and after 

 some trial was given up. The old political divisions called hundreds 

 were proposed, but found too arbitrary : and unions of parishes were 

 found to give unnatural districts difficult to determine in the field. It 

 was therefore at length determined to adopt some purely natural divi 



