INTRODUCTION. 



XUl 



know of any other objections than these, which I hope to set aside 

 by the following remarks. 



First, as to its uncertainty. That it is not open to this charo-e, 

 no one will, I think, assert; on the contrary, it is admitted on all 

 hands that it fully participates in those imperfections to which human 

 contrivances are subject, particularly such as, like natural history, 

 are from their nature not susceptible of mathematical accuracy. But 

 while no claim is advanced on its behalf to superiority in this respect 

 over artificial methods, it may be safely stated, that it is not more 

 uncertain than the celebrated sexual system of Linnaeus, the only 

 one with which it is worth comparing it. By uncertain, I mean that 

 the characters of the classes and orders of the Natural system are not 

 more subject to exceptions than those of the Linnean, as perhaps may 

 be proved from documents in the hands of every English reader. We 

 are so accustomed to believe that the certainty of the sexual system 

 is equal to its simplicity, that this opinion has acquired the nature 

 of a fixed prejudice, and we are perhaps not prepared to assent to 

 the truth of a contrary proposition. Without, however, travelling 

 out of the way, or seeking for proofs of it among books or plants 

 with which the reader is unacquainted, the following table of excep- 

 tions to the sexual system, taken from Smith's Compendium of the 

 Flora Britannica, may possibly carry some weight with it : — 



Linnean Class or Order. 





.SO 



_ t* K 1> 



g > tS 'S 



O) 02 <^ , 



^ ^^ " 



O PhU "> 



^ 8 & 



Monandria 



Triandria Monogynia 



Tetrandria 



Pentandria Monogynia 



Pentandria Digynia, excluding Umbellatse 



Pentandria Tiigynia 



Pentandria Hexagynia 



Hexandria Trigynia 



Hexandria Polygynia 



Octandria , 



Decandria 



Dodecandria 



Monoecia 



Dioecia 



5 



9 



21 



41 



8 



5 



1 



5 



1 



12 



21 



6 



24 



14 



173 



2 

 4 

 2 



43 



