156 PTERIS. 



considers the essential character to depend upon the " indusium e margine frondis 

 reflexo in limbum meinbranaceum trauseunte," to distinguish it from " Pferis, — 

 indusium margini frondis adnatum, ab ipso distinctum, limbo membranaceo." 

 He has thus preserved Pferis nearly in the same state as Professor Agardh, and 

 apparently coming to the same conclusion, quite independent of any knowledge of 

 each other's views. 



Mr. J. Smith's "Arrangement and Definition of the Ferns," though read before 

 the Linna^an Society in 1840, was not published till 1842 (in Hook. Journ. of 

 Botany, vol. iv.). This author's views, as he tells us, so nearly coincided with 

 those of Presl, that he thinks it necessary to explain that he never saw Presl's 

 'Tentamen' till 1838. Here Allosorus (Bernhardi, /. Sm.') is placed among 

 the Nudisori, and reduced to A. crispus and its supposed alUes, " J. gracilis, A. 

 cilialus, Pr., and A. hirsutus, Pr.," while the majority are united with Cassebeera, 

 Kaulf., and the rest constitute the genus Platyzoma, J. Sm., with the exception 

 of Cerafodacti/lis, J. Sm. {Allosorus, Kze.), and which I have clearly ascertained 

 to be Llavea of Lagasca. Amphiblestra is retained, and Litobrochia, with which 

 Campteria is united, and Doryopteris is formed, at the expense of Litobrochia, of 

 Pleris pahnata and its allies : but we scarcely see on what ground, since the 

 Cassebeera pedata and its affinities, which hold the same relation to that genus 

 that P. palmata does to Litobrochia, remain there. Pteris is confined to the 

 free-veined species, and stands exactly as in Presl.* 



The only remaining author worthy of notice, who has written on the Filices 

 on a comprehensive scale, and whose works generally on the Ferns are full of the 

 most valuable information, M. Fee, has, in his ' Genera Filicum ' (his ' Cinquierae 

 Mcinoire sur la famille des Fougeres ') in the main followed Presl's views. He 

 establishes the genus Heterophlebium (already noticed) ior the Pteris grandi flora, 

 L., and other authors. His Pteris however includes the ^jMz7m«-group, which 

 Presl refers to Allosortcs : and he adopts Pellcea of Link, for the species of Allo- 

 sorus, as we have ourselves done. Doryopteris is made to include the Pteris 

 articulata of Kaulfuss, which, though agreeing in venation, and perhaps texture 

 of frond, is at variance with the character of the genus : " Les frondes out une 

 forme pediaire on hastee, qui donne a ses plantes un port curieux ;" whereas P. 

 articulata has quite the habit of Pellcea, especially of Pellma hastata. 



Having thus enlarged upon the changes the genera have undergone, according 

 to the views of some of the more recent writers on Ferns, in the old genus Pteris, 

 it may be as well here, and to avoid needless repetition, to express our opinion 

 that as new light is continually being thrown upon this family of plants, it is 

 premature to sanction the great multiphcation of genera by lajing stress on the 

 nature of the venation when unaccompanied by any corresponding changes in 

 fructification or any marked differences in habit, and more philosophical to con- 

 sider such groups in the light of sections or subgenera. The importance of the 

 vascular structure is acknowledged; an arrangement, to say the least, equally 

 natural, is preserved, and some degree of stabihty is given to names invented and 

 sanctioned by the most illustrious botanists that ever lived.f 



* In his very recent ' Catalogue of Ferns in the Royal Gardens of Kew ' (1856), 

 Mr. J. Smith adopts Cryptogramme, Br., removes it from the Nudisori (or Poly- 

 podiece), and transfers it to Pterideee, and he adopts Pellaa of Link for the 

 majority of species of Platyloma, and Campteria is in part only separated from 

 Litobrochia. 



t In the first number of a little work just put into my hands, while preparing 

 this sheet, entitled ' Index Filicum,' by Mr. Thomas Moore, it is shown (though 

 I do not vouch for the accuracy) that the genus Pteris alone, and not the Pteris 

 of Linnaeus, but of more recent writers, Agardh, Fee, etc., is described under no 

 less than eighteen different generic names, Clieilanthes under fourteen, and As- 

 plenium under nineteen ! 



