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one, Polygamia. Dr. Forster observed, in his voyage 

 round the world, that this class was subject to great ex- 

 ception, on account of the trees of tropical climates, so 

 many of which are constantly or occasionally polygamous; 

 that is, each individual frequently bears some imperfect 

 flowers, male or female, along with its perfect or united 

 ones. Such a circumstance reduces any genus to the 

 class Polygamia ; and on this principle Mr. Hudson, think- 

 ing perhaps that he made a great improvement, removed 

 our Ilex Aquifolium, or Holly, thither, though Ilex is well 

 placed by Linnaeus in the fourth class. The author of the 

 present essay has ventured to propose a scheme, which is 

 adopted in his Flora Britaimica, for getting clear of this 

 difficulty. He considers as polygamous such genera only 

 as, besides having that character in their organs of im- 

 pregnation, have a difference of structure in the other 

 parts of their two kinds of flowers. Thus Atriplex has, in 

 its perfect flowers, a regular spreading calyx, in five equal 

 segments ; in the attendant female ones a compressed 

 one, of two leaves, subsequently much enlarged. 



The genera thus circumstanced are so very few, as far 

 as we have discovered, that possibly the class might, but 

 for the uniformity of the system, be abolished. We can- 

 not indeed tell what future discoveries may be made ; and 

 its character, on the above foundation, is sufficiently clear 

 and permanent; for flowers of an essentially different 

 configuration, can hardly vary into each other. The or- 

 ders of the last class of the Linnaean system, Cryptoga- 

 mia, are natural, and preserved, all nearly the same, by 

 every systematic projector. The original appendix to 

 this system, the Palmce, would be a great blemish therein, 

 as an artificial arrangement : for such an arrangement 

 ought to be so formed as to admit every thing, on some 

 principle or other. But this stumbling-block is now re- 

 moved. The palm tribe were placed thus by themselves, 

 merely till their fructification should be sufficiently known. 



