XXXIV INTRODUCTION. 



directly brought to his notice on good personal authority at any 

 later date. 



The name of a personal authority or witness for the county is 

 added from one of the three following sources. First, the 

 labels of specimens (sp.) still preserved in the Compiler's 

 herbarium, or which have passed through his hands for 

 inspection. In the former of these two cases the specimen 

 may have reached the herbarium through intermediate persons, 

 the donor and collector not being identical ; and as the space 

 at command cannot admit two or three names, sometimes it 

 may be the name of donor, sometimes that of collector, which 

 is cited; usually the latter. Second, other manuscript (ins.) 

 notes of localities communicated by correspondents, on whose 

 good faith and prevailing accuracy due reliance can be placed. 

 These notes have frequently been sent in the form of remarks 

 in letters, and some of them afterwards withrawn or corrected ; 

 and it is possible that, in now reverting to them for use here, 

 the first remark may turn up again apart from the forgotten 

 correction. Third, local catalogues (cat.) of plants drawn up 

 by botanists resident in or visiting the places to which the 

 catalogues are made to relate. These lists have usually been 

 made out by marking in a copy of the * London Catalogue 

 of British Plants ' the names of all those actually seen by 

 the marker within the area under consideration ; separate 

 marks being used to distinguish between the indigenous and 

 introduced plants. 



No fixed rule can be laid down as to precedence in the 

 citations ; perhaps most usually a preference will be given 

 to the " sp." But "cat." may often come more readily to 

 hand, and thus be cited instead, without always implying 

 that no specimen has been seen from the county. The printer 

 is instructed to leave out the abbreviations (sp. ms. cat.) if 

 want of space in the half line may render such an omission 

 necessary. Only a single selected authority can be cited 

 within the space allotted; although in many cases there may 



