EXPLANATIONS OF THE FORMULA. 57 



logue,' by reason of their insufficient claim to be accounted 

 British, are without numbers to their names. On account 

 of such species having been elsewhere reported as native or 

 naturalised plants, it appeared desirable to make some slight 

 mention of them in the pages of this work. 



In the larger and discontinued edition, before adverted 

 to, a woodcut was given with each species, to assist the eye 

 of the reader by a visible diagram of its distribution. In 

 the more condensed plan of the ])resent work, it has been 

 deemed advisable to omit that illustration ; some hope be- 

 ing retained, that the omission may be equally well com- 

 pensated for, hereafter, although in a different manner. 

 The scries of figures in the first line, underneath the name 

 of the plant, will answer the same purpose tolerably well for 

 the present. The facts are the same, whether told in a line 

 of text, or shown in a diagram; but it requires a certain 

 mental effort in readers, to conceive the figures in situ, if 

 shown only in a line. 



Underneath the name of the species, ten lines are devoted 

 to an epitome or condensed sketch of its distribution within 

 Britain. They are designed to show those circumstances 

 which are requisite for the pm-pose of enabling botanical 

 geographers to make comparisons between the floral statis- 

 tics of different portions of the earth. It is hoped that the 

 use and application of these data, to the purposes of sci- 

 ence, will become sufficiently apparent, as the present work 

 advances ; although, to persons little acquainted with its 

 subject, such applications cannot be so clearly apparent 

 while species are treated singly and successively. 



The first line shows, by their nuinbers, the provinces 

 within which the species has been ascertained or reported to 

 grow. The uninclosed numbers show those provinces in 

 which it is so far wild or established as to be faii-ly con- 

 sidered a British species — native, denizen, or colonist, as 



I 



