PD EG «A C.F. XV 
it became neceflary to give up the Order of 
- the Parts of the Vegetable, and follow that of 
the Syftem. 
The Syftem is divided, 1. into Claes. 2. Or- 
ders. 3. Genera. 4. Species. 5. Varieties. Now 
as the Clafles, Orders, and Genera, which come 
firftin the Syftem, are eftablifhed on the Fruéti- 
fication alone, it became neceffary to give this 
Part of the Vegetable the Preference in Point 
of Order; and we have accordingly made the 
Fructification the Subject of the feveral Chapters 
of the firft Part of this Work. 
In the fecond Part, we have given a full Ex- 
plation of the Clafes, Orders and Genera of the 
Syftem; which indeed contain the whole Theo- 
retic Part of it, the Doétrines of Species and Va- 
rieties having, as Linnaus obferves, a nearer Re- 
lation to the Praétice. The Reafon for proceed- 
ing to the Syftem immediately after the Fructi- 
fication is manifeft; as the Theory of the Syftem 
is eftablifhed on the Fructification alone, an Ac- 
count of the latter was all that was neceflary to 
prepare the Reader for underftanding the Ex- 
planation of the former, which, as has been faid, 
was the principal Object of the Work. 
a4 In 
