It is not, indeed, supposed that the present work is without 

 glaring faults, of which no one can be more sensible than the 

 Author. Whatever faults, however, it may contain, they are not 

 in general ascribal^le to carelessness. An incredible amount of 

 labour has been bestowed upon its preparation, in the exami- 

 nation of herbaria, the consultation of authorities, and the 

 verification of facts. Nor has he rested on his oAvn judgment, 

 but has profited by the counsel of friends, who have in more 

 than one instance contributed valuable notes on subjects in 

 which they are the highest authorities. Sir W. J. Hooker 

 not only opened his rich Herbarium and Library, but gave 

 much oral information on Ferns, Mosses, and Jungermannise ; 

 Dr. Hooker supplied some admirable notes on the geographical 

 distribution of Ferns, besides giving much advice on a variety 

 of subjects during the progress of the work ; and Mr. Churchill 

 Babington has contributed far the greater part of the informa- 

 tion on the distribution of Lichens. The Author's most grateful 

 thanks are due to these and other Botanists who have so 

 readily acceded to his washes, or have taken interest in his 

 labours. 



It remains only to state that the work is not intended nor 

 calculated for persons who have not already some general 

 knowledge of Botany. At the same time it is beheved, unless 

 the Author has entirely failed in his attempt, that there is no 

 part which is not intelligible to any one who has made himself 

 master of Dr. Lindley's or Dr. Balfour's Introductions to the 

 Study of Botany. 



King's Clctfe, 

 Fehruary \Qth, 1857 



