PREFACE TO THE THIRD VOLUME. 
Tie subjects of the present work, for reasons 
which prevail in many publications of the kind, 
have been inserted without reference to any par- 
ticular arrangement or system. ‘Those plants 
yeceived the earliest place, the observations re- 
specting which were earliest matured, and the 
drawings of which were first completed. Al- 
though this plan has been objected to in some 
foreign criticisms, it is the one pursued in several 
of the most extensive and useful botanical works 
of the day, which are accompanied with plates ; 
and in periodical publications, or those which 
appear in successive numbers, it has more than 
one decided advantage. It gives time for all the 
figures to be completed at leisure, from perfect 
. specimens, in proper and convenient seasons ; at 
the same time that it does not necessitate prema- 
ture and imperfect descriptions of their subjects, 
which must take place were an arrangement adopt- 
