MOXOECIA. 357 



sponding Classes. Heptandria and Tetrandria, 

 Zostera, the only remaining genus of Gynandria 

 Poli/andria in Linnaeus, I have long ago ventured 

 to remove to Monandria Monogynia ; see Engl. 

 Bot, t. 467. 



Class 21. Monoecia. Stamens and Pistils in separate 

 flowers, but both growing on the same individual 

 plant. Orders 9 or 10. 



Several reformers of the Linnrean system have also 

 abolished this Class and the two following, by way of 

 rendering that system more simple. Ten years* addi- 

 tional experience since the preface to the seventh 

 voliime of EnglUh Botany was written, have but con- 

 firmed my opinion, there given, on this subject. If 

 any plants ought to be removed from these Classes, 

 they must be such as have the structure of all the 

 accessory parts of the flower exactly alike, (the essential 

 parts, or stamens and pistils only, difl'ering,) in both 

 barren and fertile flowers ; and especially such as have 

 in one flower perfect organs of one kind, accompanied 

 by rudiments of the other kind, for these rudiments 

 are liable occasionally to become perfect. By this 

 means dioecious species of a genus, as in Lychnisy 

 Valeriana, Rume.v, &c., would no longer be a re- 

 proach or inconvenience to the system. But, on the 

 other hand, some difliculty would occasionally arise to 

 a student, in deciding whether there were any real 

 difl'erence of structure between these accessory partsor 



