66 FERNS : BRITISH AND FOREIGN. 



wards be placed. But as many species of Linnseua, 

 Swartz, and other old, as well as modern authors, 

 are but indifferently described, many being derived 

 from imperfect specimens, and with nothing but the 

 meagre description left us for their identification, it 

 frequently happens that some modern author detects, 

 or supposes he has found out, that the new species of 

 his contemporary is one of the Linnasan or Swartzian 

 doubtful species, and faith in his decision being 

 admitted, familiar names become changed, thus bur- 

 dening the science with additional synonyms, and 

 rendering it in many cases impossible to reconcile one 

 author's views with another. As an instance of the 

 different views of authors on the identification of 

 species and their synonyms, the genus Asplenium is a 

 good example, it having within these few years, and 

 near about the same time, been revised by Dr.Mettenius, 

 Sir W. J. Hooker, and Mr. Moore. The two latter 

 had the advantage of profiting by Dr. Mettenius's 

 views, but in a great many cases I find it quite impos- 

 sible to reconcile or agree with the views of either. 

 As an example of the different views, I will cite the 

 plant known in gardens for the last forty years by the 

 name of Asplenium Sheplierdii. The above-mentioned 

 authors place it as a synonym, each under a different- 

 species and with different synonyms. To show the 

 impossibility of reconciling one with the other, it will 

 be sufficient to notice that in the Index Filicum it is 

 found as one of twenty-three synonyms under Dipid' 

 zium radicans. Believing as I do that these synonyms 

 represent several distinct species, and the plant in 

 question being one of them, I deem it best to retain 

 it under the name it has been so long known bv, and 



