vi PREFACE. 



Acknowledgments are here rendered to those who have aided 

 in the preparation of this edition. Especially we would men- 

 tion Dr. Sereno Watson, of the Botanic Gardens at Cambridge 

 for access to numerous specimens ; Professor Daniel C. Eaton, 

 of Yale, for elucidating the synonymy of Asptdium pattdum ; 

 and most of all, Mr. George E. Davenport for very many kindly 

 suggestions, specimens, and courtesies extending through a 

 series of years. 



SYRACUSE UNIVERSITY, 

 Feb. 18, 1888. 



PREFACE TO FIFTH EDITION. 



IN the fourth edition (1893) numerous changes were made: 

 (i) by rewriting several of the chapters, (2) by the addition of 

 four species new to our flora, and (3) by the modification of 

 the nomenclature to conform with the " Rochester rules." The 

 further amendment of these rules at Madison, Wisconsin, 

 in August, 1893, renders necessary two or three additional 

 changes. It is also a pleasure to record two additional species 

 which have been found in the country since the fourth edition 

 was published, viz., Dryopteris simulata from New England, and 

 Equisetum Mexicanum from Southern California, the former 

 described by Mr. George E. Davenport, and the latter discov- 

 ered by Prof. A. J. McClatchie of Pasadena, California. The 

 total number described is, therefore, 230 ; of these 1 59 are ferns 

 and the remaining 71 are fern allies. In other respects the 

 present edition is essentially the same as the fourth. 



AUBURN, ALABAMA, 

 Nov. 15, 1895. 



