PREFACE. 



This work, so long announced, is at last completed. Begun 

 three years ago, and at first interrupted by ill-health and 

 other causes, for the last twenty months it has been the subject 

 of continuous labour. 



When I undertook the task of compiling a Guide to the 

 Literature of Botany within the compass of a few months, I 

 much underrated the magnitude of the task I had set myself 

 to do. In common with most people, I believed Pritzel's 

 Thesaurus to be practically complete to the end of 1871'; I 

 fancied therefore I had but to select from that storehouse, add 

 the titles of such new books as had since appeared, and arrange 

 the whole in the order of subjects. The delay in the issue 

 of the present work is chiefly due to the unlooked-for heavy 

 labour which was found necessary to produce a result which 

 could be deemed satisfactory. 



The history of my work is as follows. Having agreed to 

 compile a classified subject-index of short titles, I began by 

 extracting from Pritzel such as I thought should be included. 

 In order to attain the brevity necessary to compress my 

 subject within the limits of about two hundred pages, I decided 

 to reject certain classes of works, unless some special reason 

 should plead for their retention. Thus I shut out the greatest 

 portion of introductory works in foreign languages, theses, 

 lectures, inaugural dissertations, works of more medical than 



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