A LIST OF THE FERNS AND FERN ALLIES OF NORTH 

 AMERICA NORTH OF MEXICO, WITH PRINCIPAL SYNO- 

 NYMS AND DISTRIBUTION. 



By William R. Maxon, 



Ai<1 in ('I'liptogumic Botany, Division of Plants. 



In all the literature relatino- to American ferns and the so-called 

 " fern allies/'' there have hitherto appeared but two systematic treatises 

 of sufficiently wide scope to include the entire territory of North 

 America north of Mexico, namely, the Ferns of North America, b}' 

 Prof. D. C. Eaton (1877-1880), and Our Native Ferns and Their Allies 

 (in several editions, 1881-1900), by Prof. L. M. Underwood. The 

 first of these, a monograph of two large quarto volumes, contains 

 descriptions and colored figures of all species comprised in the groups 

 know^n at that time as the orders Filices and Ophioglossaceae. The 

 treatmtni: is full but concise, the style clear, the figures for the most 

 part excellent; and the work as a whole must be regarded as the founda- 

 tion for all subsequent studies of North American ferns. Without 

 its good influence it is unlikelv that the present degree of progress 

 could have been attained-, but we should remember first of all that it 

 represents a critical estimate of the groups as they were understood 

 over twenty years ago, and that since its appearance there has elapsed 

 a period marked by unexampled botanical activity and progress. 

 There has been collected in the meantime abundant material of many 

 species either entirely new or then represented in herbaria l)y mere 

 fragments, and with the aid of these specimens careful studies have 

 been accomplished in the light of which not only new specific names 

 have been proposed, but many changes in the older definitions of spe- 

 cies have been shown to be desirable. If, then, we recognize that there 

 have been and must continue to be many departures from the treat- 

 ment contained in Professor Eaton's great work, we ma}- escape that 

 extreme conservatism which occasionally manifests itself in opposing 

 innovation of almost any sort, and which regards the setting aside of 

 an opinion there expressed as a proceeding hardly within the bounds 

 of propriety". 



Proceedings U. S. National Museum, Vol. XXIII— No 1226. 



619 



