PREFACE. 
SixcE the completion of the Synopsis Planta- 
rum Succulentarum, the procession of time, and 
the consequent progress of our knowledge concerz.- 
ing the difficult plants which it is the peculiar bu- 
siness of that publication to explain, have advanced 
with steady and successful steps. And the Author's 
unwearied friends, and increasing opportunities, 
have enabled him to accumulate, digest and ar- 
range, in Linnzan Classes, the materials contained 
in the subsequent pages; which he humbly trusts 
will be found acceptable to the admirers of Succu- 
lent Plants, and not unuseful to Botauists at large : 
not merely on account of the new species those 
pages propose, describe, and teach how to incor- 
porate with the ancient stock ; but especially by 
B 
