vi PREFACE. 
subject. Influenced in this way, I have gone over 
the volume very carefully, and brought it up as 
far as I could to the present state of knowledge 
regarding the topics upon which it treats. Several 
striking and novel facts connected with all the 
departments, and especially with fungi, I have 
been compelled for want of space to omit alto- 
gether; while I have been led by the popular 
nature of the book to glance briefly and super- 
ficially over subjects which are worthy of the 
profoundest study; and upon which, in other 
circumstances, I should have liked to dwell at 
more adequate length. I believe, however, that 
nothing of any real importance has been left out. 
It is confessedly a difficult task to make such 
obscure subjects intelligible and interesting to the 
ordinary reader without sacrificing scientific ac- 
curacy. Whether I have succeeded in doing so 
it is not for me to say; but I am sure that 
those who best know the difficulty will be most 
ready to sympathize with my attempt, and to 
generously overlook all its imperfections, of which 
none can be more sensible than myself. 
Upwards of a hundred pages of new matter 
have been added; and eleven new illustrations 
