INTRODUCTION. XXX111 



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 deemed 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 Dublin 

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

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

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

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



