VII. FORMULA EXPLAINED. 65 
of experience, there can be only very few known British plants 
which he has not seen living or dried. All such plants or names, 
however, will have a brief notice in the latter portion of this work. 
The records of localities in local guide-books, county-histories, and 
such-like publications, are usually altogether ignored; unless in 
those cases where they have been already adopted into some work 
expressly botanical; an adoption unfortunately far too frequent, and 
giving permanence to many errors. In such cases, the usual 
ordeal for acceptance or distrust is applied to them here; hence 
the rejection of many plants adopted into Ravenshaw’s Devon 
Flora, Balfour's Edinburgh Flora, etc., on bad authority or no 
authority. The original series of the Phytologist has been care- 
fully consulted throughout, and has been found highly serviceable 
in its numerous facts, although not free from occasional errors by 
correspondents. But the ‘ New Series” of that periodical, under 
its incompetent editorship, and largely contributed to by ignorant 
pretenders in botany, has been wholly ignored, as standing too 
far below the grade of scientific reliability. The statements of 
some few individual botanists and collectors are also disregarded, 
through grave distrust of their good faith or their botanical know- 
ledge. If anything else has been overlooked, which ought to 
have altered the filling in of the formula under any species, it 
may be attributed to the errors or oversights which must be 
unavoidable in a work involving in its preparation the collection 
and examination of thousands upon thousands of special details ; 
often very petty details, if looked at singly and separately, not in 
their collective bearings. e 
The First line of the Formula traces the area of the plant 
within Britain, from south to north, by citing the nos. of those 
provinces, as explained on pages 8 to 5, in which it has been 
reported to occur. The enclosure by crescent curves () dis- 
tinguishes the provinces into which the species is known or 
suspected to have been introduced through human agency, 
although it may be indisputably native in other provinces. 
In various cases of plants being fairly accounted indigenous in 
EK 
