#60 PRINCIPLES OF BOTANY, ETC. 
ders have been improved and extended. The most 
successful labourers on the subject have been Barsc# 
and Jusstru, but especially the latter. 
Barscu has established 77 families, which, with 
a few exceptions, are pretty natural. Jussizu, whe 
had an opportunity of seemg a much greater num- 
ber of plants, has described 100. families, 
§ 144. | | 
The aboye may suffice to give the beginner a 
slicht idea of the most important systetas: a ge- 
neral view will shew us what remains to be dene, 
and will convince us, that m the innumerable and 
endless varieties in the structure of plants, human. 
ingenuity will never be able to contrive a perfect 
system. 
WT. BOs 
