x a PREFACE. 
~The reader will find in the present . edition, 
many Species added to the British Flora; some of, 
them non-descript: A few have been discarded. be- 
cause confessedly not indigenous, but some doubt- 
ful ones are yet retained, upon the principle, that 
their retention can produce no inconvenience, 
whilst their omission might = a real defect. 
“In the Cryptogamia class, and in some other 
patts where the Species are’ very numerous, new 
arrangements have been attempted, in hopes of 
facilitating their investigation. The system of 
Agarics formed for the second edition, has been 
improved, and considerably augmented: and lastly, 
_ to gain more room, the uses of the different plants 
have beén thrown into Notes at the foot of the 
page. ge! 3 
~ The Author cannot conclude without expressing 
his gratitude for the very liberal assistance he has 
experienced, and his hopes of its continuance; con- 
scious that the efforts of any individual would avail 
but little towards perfecting the — of the 
pore Islands. 
Besides the list of contributors to the present 
edition he begs leave more particularly to mention 
the respectable names of, Mr. Arzetivs, Demon-- 
_strator of Botany in the University of Upsal, who 
looked over great part of the Author's collection, 
