PREFACE. 



When the writer issued this little book in 1880 as the 

 honest effort of a novice to provide for the study of our ferns 

 a convenient handbook by means of which they might be 

 identified, he had no idea that the first edition would be 

 exhausted within a year, and much less that a sixth edition 

 would ever be called for. Though frequently urged to 

 extend its scope, he has felt that if, with all the traces of its 

 early imperfections of plan, there is still a demand for such a 

 handbook, it is best to leave it in its original form, with only 

 such changes as our changed conceptions of structures, 

 relationships, and definition of species demand. Not only 

 is this preservation of the original plan in harmony with the 

 feeling of sentiment, but it seems the more desirable since the 

 writer is preparing a monograph of all the North American 

 Ferns (including those of the West Indies and the continent 

 as far as the Isthmus), and in this more elaborate work he 

 hopes from a study of a wider range of forms to include 

 many more general matters that our own limited fern flora, 

 though quite diverse, do not furnish a sufficient basis for 

 inclusion here, and others still that would be out of place in 

 an elementary manual. 



Changes in this edition are mostly verbal and such as arise 

 from the modifications of nomenclature or the changed 

 ideas of homologies and relations of structures. The chapter 

 on nomenclature has been wholly rewritten and extended, 

 particularly because the present edition more than any other 

 contributes to a modification of generic names. 



V 



