X PREFACE. 



botanical interest, and foreign local floras of narrow boundaries ; 

 I rarely gave two works by the same author on the same 

 subject, but selected that one I thought most advisable. For 

 example, Dr. Engler has produced a thesis, and a monograph, 

 of the genus Saxifraga ; I have included the latter but not 

 the former. Of course the selection is not of easy accom- 

 plishment ; I have endeavoured to judge every case on its 

 own merits, and where I could hardly decide on certain 

 doubtful books, I have chosen to err on the side of inclusion 

 rather than the reverse. I have given Belt's Naturalist in 

 Nicaragua, but excluded its confessed model, Bates's Naturalist 

 on the Amazons, purely on these grounds. Tn doing this, I 

 had to consider whether the amount of botanical information 

 given was sufficient to warrant the citation of the book. 

 Another point was, what were to be considered indej)endeut 

 publications ? I laid down these two canons : the possession 

 of separate pagination, and a full title-page ; the existence 

 of both of these was essential for the right of any tract to 

 be included in the Guide. I have explained some of these 

 matters elsewhere,^ and need not here repeat much of what I 

 have already sjjoken. In a few instances I have found it 

 needful to relax the stringency of my rules, but such cases 

 are not common. I have chosen to be sometimes inconsistent, 

 for the sake of including an important work, which would 

 have been shiit out by rigorous observance of these rules. 



The aim I set before myself was to give all the works 

 likely to be wanted by my fellow-countrymen, either for a 

 knowledge of their own botanical literature, local and colonial 

 floras, or for trade ; keeping specially in view those districts 

 likely to be visited by the traveller from these shores. I have 

 1 Trimen's Journal of Botany, 1880, pp. 167-177. 



