LINN^US. 299 



Monoecia and Dioecia, the characters distinctive of 

 the classes are employed for the orders. Polygamia 

 has three orders, Monceda, Dioecia, Trimcia ; and 

 the last class, Cryptogamia, is divided into four or- 

 ders, consisting of the Filices or Ferns, the Musci 

 or IMosses, the Algce, and the Futigi. 



The genera are established upon characters derived 

 from all the parts of fructification compared together, 

 according to their number, figure, proportion, and 

 situation ; but as this volume was intended to con- 

 tain all the plants known to the author, the natural 

 characters thus formed could not be employed on 

 account of their length, and he has used the essential 

 cliaracter, which is shorter, and consists of those 

 marks that serve to distinguish the genera from each 

 other in the natural orders ; while at the head of 

 each class, the genera are synoptically disposed, be- 

 ing defined by their factitious characters, or those 

 by which one is distinguished from another in the 

 artificial order only. 



The remarks which we have already made re- 

 specting the generic and specific names, apply equal- 

 ly to this department. These last, in the systems 

 of former botanists, were lengthened descriptions, 

 taken from various circumstances, and seldom in 

 any degree distinctive; but Linnajus reduced them 

 to twelve words at most, and derived them from 

 some remarkable difference in the leaves, roots, 

 stems, or other unvarying properties. These short 

 phrases he continued to call the specific name, but 

 they are now properly considered as the specific 

 character ; while he invented what he called the 

 trivial name, consisting of a single word added to 

 the generic, and which we now use as the specific. 



