ADVERTISEMENT, 
In this Edition, the Errors of the former are corrected; the 
number of genera is taken from the 8th edition of the Genera 
Plantarum, by Thaddaeus Haenke, member of the Scientific 
Society at Prague, printed in 3/91 ; which includes all the 
genera (amounting to 1683) discovered to that time, by Lin~ 
naeus, Forster, Thunberg, L. 'Heritier, Swartius, Aiton, and 
others.—In this edition of the ^genera (and it is said by the 
instruction of Dr. Thunberg) four of the original classes of 
Linnaeus are omitted, viz. gynandria , moncecia , dioecia, and 
pofygamia ; as also the appendix : And the several genera 
are incorporated with the other classes according to the num¬ 
ber of males and females to each genus ; But the prowcling 
the regular classes with plants of such different singularities 
in their sexual disposition, seems such a mutilation of the 
Linn .as an System, as I cannot approve of, till sanctioned 
by more general authority ; for it seems much more pleasing 
to see plants of particular singularities ranged together; be¬ 
sides the great confusion and inconvenience that will arise to 
all modem writers who have adopted the regular system of 
Linnseus, which hath now been long established and approved. 
The number of species is taken from the 14th edition of the, 
Systema Vegetabilium , by Dr. Murray, printed in 1784, which 
includes all the genera and species of Linnmus the elder, and 
