INTRODUCTION. XXxilL 



sincere thanks : — Professor Don, who has afforded me 

 every possible information on the subject of nomen- 

 clature, and in no single instance have I intentionally 

 changed a name in opposition to his views. This asser- 

 tion seemed requisite in justice to myself, lest, having,^ 

 in some way or other, altered more than half the 

 names employed by Sir J. E. Smith, (and therefore in 

 general use,) I might perchance be charged with the 

 most paltry of all ambitions — the desire to subvert an 

 established name : Mr. Smith, of the Royal Botanic 

 Gardens at Kew, who has also assisted me in the 

 nomenclature of genera, and of whom I have else- 

 where spoken ; Mr. Foster, ' the highly respected 

 Vice-President of the Linnean Society ; Mr. Ward, 

 of whose excellent plan of cultivating Ferns I have 

 already said so much, and whose extensive collec- 

 tions, both of living and dried specimens, have always 

 been open to me ; Mr. C. C. Babington, of Cam- 

 bridge, whose collection and valuable notes have 

 been unreservedly placed in my hands ; Mr. White, 

 of Cloudesley-square, who has taken infinite pains to 

 determine for me the venation in Pteris, Lomaria, 

 Ceterach, and indeed in every genus that presented 

 any difficulty ; Mr. Bowerbank, whose splendid micro- 

 scope has been constantly at my service ; Dr. Gre- 

 ville, of Edinburgh; Mr. Moore, of the Dubhn 

 Society's Botanic Garden ; Mr. R. Ball, of Dubhn ; 

 Mr. J. Ball, of Cambridge ; Mr. Heysham, of Carhsle; 

 Mr. E. J. Quekett, of Wellclose-square, London ; Mr. 

 T.B. Flower, of Surry-street, Strand, London; Miss 



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