50 



ox GEXEKA A'JD SPECIES 



extended only to Goniophlebium, being- tlie seventy-third 

 g-enus in alphabetical order, up to which are enumerated 

 1,738 species with their synonyms ; from this data it may 

 be calculated that the number of species, when the work is 

 complete, will amount to above 4,000. As an instance of 

 the labour and investigation required, I will select the 

 g'enus Acrosiichum. Under this original generic name of 

 Linnaeus, no less than 401 specific names are enumerated 

 in alphabetical rotation, with references to their authorities, 

 occupying twelve pages : with the exception of nine names, 

 the whole are in italics, signifying that they are synonyms, 

 the nine being in roman typo, indicating that they are the 

 only true species of Acrnsticlmiii as now adopted. When 

 complete, this work will be an invaluable treasure to 

 Pteridologists. 



I have now to notice the works of Sir William Hooker , 

 who in 1820 became Professor of Botany in the University 

 of Glasgow, and in 1841, Director of the Roj-al Gardens 

 at Kew, but before the first date he had gained reputation 

 as a crj'ptogamic botanist. His first g-reat work on Ferns 

 was in conjunction with Dr. Greville, of Edinburgh, also a 

 famous crj'ptogamio botanist, entitled " Icones Filicum," a 

 Vv'ork of two folio-sized volumes, containing 2.30 finely 

 executed plates of new and rare Ferns, each plate con- 

 t.aining niag-ulfied portions of the fructification exhibitinn- 

 the characters of the genera as then defined, with accom- 

 panying descriptive letter-press. In this work two new 

 genera are characterised, viz., Deparla and Jamesonia, each 

 founded upon a sing-le species. 



His next work of importance is Hooker and Bauer ',s 

 " Genera Filicum," which commenced with a set of draw- 

 ings begun in 1833 by the late eminent botanical draucrhts- 

 man Francis Bauer, from specimens from time to time 



