is the case here as with other scientific systems ; those are the best cha- 

 racters which lead to a knowledge of the object sought for in the nearest 

 and clearest way, keeping in view also as much as possible its natural 

 affinities. The difficulties certainly are greater in the cryptogams than 

 among the flowering plants, because their characters are fewer, and the 

 forms of their organs more variable as regards size and shape. 



In regard to the genera, the publisher has judiciously desired that nine 

 plates should be devoted to their, illustration. They are all drawn from 

 nature by the talented Mr. Fitch, F.L.S., and on the same plan as the 

 plates of Ferns in Hooker and Arnott's late editions of the "British 

 Flora." 



References are given to the volumes and pages of the "Species Filicum" 

 for fuller characters of the genera and species, as well as for figures, more 

 precise localities, and more copious observations ; and it is hoped that 

 the present volume will form a useful vade-mecum for the travelling 

 botanist and the cultivator of Ferns, and for ready consultation in the 

 Herbarium. 



The Author cannot close these introductory remarks without expressing 

 his acknowledgments to numerous friends and correspondents for their 

 valuable communications of specimens (often accompanied by notes) from 

 various parts of the world. Many of these are recorded under their habitats 

 (or localities) in his former work ; and a repetition of them would be out of 

 place in this. But space must still be found for the names of those persons 

 to whom we are indebted for the discovery of any new species, or any new 

 or interesting locality in connection with the geographical distribution of 

 plants. 



The commencement of the Author's formation of a Fern-Herbarium 

 dates as far back as 1811, with the correspondence of the illustrious Swartz, 

 only four years after the publication of his invaluable " Synopsis Filicum;" 

 a model for future works of the kind. It is, however, from comparatively 

 new and distant regions, which have been within the last half-century so 

 extensively explored by our men of science, that the most important collec- 

 tions have been derived, and to these botanists and travellers he is anxious 

 thus to express his obligations : 



From the East Indies, including the Malay Peninsula and Islands : 

 From Wallich, Buchanan, Hamilton, Hooker fil. and Thomson, Gideon 

 Thomson, Beddome, Lady Dalhousie, Anderson, Falconer, Jamieson, Edge- 

 worth, Sir Frederick Adam Jacquemont, Blume, Miquel, De Vriese, 

 Teijsmann, Sir William Norris, Thomas Lobb, Cuming, Wallace, Low, 



